阅读说明：本技术 电梯轿厢位置确定方法、装置、计算机设备和存储介质 (Elevator car position determining method, elevator car position determining device, computer equipment and storage medium ) 是由 陈刚 黄立明 钟海峰 李晓明 刘贤钊 张彩霞 于 2020-06-04 设计创作，主要内容包括：本申请涉及一种电梯轿厢位置确定方法、装置、计算机设备和存储介质。方法包括：获取安装在电梯轿厢外表面的测距雷达从初始位置进行反射板切换的切换次数,根据切换次数确定测距雷达当前时刻对应的目标反射板的反射板标识；反射板依次间隔地设置在电梯井道的侧壁上；获取通过测距雷达得到的当前时刻的测量距离,根据测量距离,得到测距雷达与目标反射板之间的相对高度；测量距离为测距雷达与目标反射板之间的距离；获取与反射板标识对应的基准距离；基准距离为目标反射板与基准反射板之间的垂直距离,基准反射板为与电梯井道的底坑或顶部距离最近的反射板；根据相对高度和基准距离,确定电梯轿厢的当前位置。采用本方法能够保证测距雷达的精确度。(The application relates to an elevator car position determination method, an elevator car position determination device, a computer device and a storage medium. The method comprises the following steps: acquiring the switching times of a distance measuring radar arranged on the outer surface of an elevator car for switching a reflector from an initial position, and determining a reflector identifier of a target reflector corresponding to the distance measuring radar at the current moment according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals; obtaining a measurement distance of the current moment obtained by a ranging radar, and obtaining the relative height between the ranging radar and a target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate; acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is the vertical distance between the target reflecting plate and the reference reflecting plate, and the reference reflecting plate is the reflecting plate closest to the bottom pit or the top of the elevator shaft; the current position of the elevator car is determined from the relative height and the reference distance. The method can ensure the accuracy of the range radar.)

1. A method of determining elevator car position, the method comprising:

acquiring the switching times of a distance measuring radar arranged on the outer surface of an elevator car for switching a reflector from an initial position, and determining a reflector identifier of a target reflector corresponding to the current moment of the distance measuring radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

Obtaining the measurement distance of the current moment obtained by the ranging radar, and obtaining the relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

determining a current position of the elevator car based on the relative height and the reference distance.

2. The method of claim 1, wherein the step of obtaining a reference distance corresponding to the reflector plate identifier comprises:

inquiring a preset database according to the reflecting plate identifier to obtain a plurality of distances between the target reflecting plate and the reference reflecting plate; the preset database stores the distance between every two adjacent reflecting plates;

and adding the plurality of intervals to obtain a reference distance corresponding to the reflecting plate identifier.

3. The method of claim 2, wherein the spacing between two adjacent reflective plates is obtained by:

Acquiring echo signals of the two adjacent reflecting plates; carrying out fast Fourier transform processing on the echo signals to obtain signal peak values corresponding to the echo signals;

and acquiring the difference value of the distance of the signal peak value corresponding to each echo signal as the distance between every two adjacent reflecting plates.

4. The method of claim 1, further comprising:

when the ranging radar receives echo signals from a plurality of reflecting plates, respectively acquiring the signal intensity of the echo signal of each reflecting plate;

determining a reflecting plate with the maximum signal intensity from the reflecting plates;

generating a control instruction according to the reflecting plate with the maximum signal intensity, and sending the control instruction to the ranging radar; and the control instruction is used for triggering the ranging radar to mark the reflecting plate with the maximum signal intensity as a target reflecting plate.

5. The method of claim 1, wherein the step of obtaining the relative height between the range radar and the target reflecting plate from the measured distance comprises:

acquiring an included angle between the range radar and the outer surface of the elevator car;

Calculating the product of the measured distance and the cosine value of the included angle as the relative height between the ranging radar and the target reflecting plate;

the step of determining the current position of the elevator car based on the relative height and the reference distance comprises:

acquiring a first vertical distance between the reference reflecting plate and a plane where a top or a pit of the elevator shaft is located, and a second vertical distance between the ranging radar and the bottom or the top of the elevator car;

determining a current position of the elevator car based on the first vertical distance, the second vertical distance, the relative height, and the reference distance.

6. The method according to any one of claims 1 to 5, further comprising, after the step of obtaining the measured distance of the current time obtained by the range radar:

acquiring a plurality of flat layer distances corresponding to the reflecting plate marks from a database; the leveling distance represents the relative distance between the ranging radar and a target reflecting plate corresponding to each leveling when the elevator car reaches each leveling position;

determining a target flat bed distance equal to the measuring distance from each flat bed distance;

And acquiring a flat floor identification corresponding to the target flat floor distance, and determining the flat floor where the elevator car is located currently according to the flat floor identification.

7. The method of claim 6, further comprising:

acquiring each reference flat layer distance of the elevator car at a reference temperature, and acquiring a first distance of the ranging radar relative to a correction reflecting plate at the reference temperature; the correction reflecting plate is arranged on the outer side of the elevator car and is a set distance away from the ranging radar;

acquiring a second distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected;

correcting each leveling distance of the elevator car at the temperature to be corrected according to each reference leveling distance, the first distance and the second distance;

and/or the presence of a gas in the gas,

acquiring the reference distance between every two adjacent reflecting plates at the reference temperature;

and correcting the distance between every two adjacent reflecting plates at the temperature to be corrected according to the reference distance, the first distance and the second distance.

8. An elevator car position determining apparatus, the apparatus comprising:

The reflecting plate identification determining module is used for acquiring the switching times of the reflecting plate switching of the ranging radar arranged on the outer surface of the elevator car from the initial position and determining the reflecting plate identification of the target reflecting plate corresponding to the current moment of the ranging radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

a relative height acquisition module, configured to acquire a measurement distance at the current time obtained by the ranging radar, and obtain a relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

the reference distance acquisition module is used for acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

and the car position determining module is used for determining the current position of the elevator car according to the relative height and the reference distance.

9. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 7.

Technical Field

The present application relates to the field of elevator car technologies, and in particular, to a method and an apparatus for determining an elevator car position, a computer device, and a storage medium.

Background

With the development of society, elevators have gradually become essential equipment in various buildings in order to facilitate people's lives. In order to ensure the safety of the elevator operation, it becomes important to measure the position of the elevator car and determine the position of the elevator car. At present, the radar ranging mode is mostly adopted in traditional measurement to elevator car position, installs the radar in positions such as well top, pit, car top and car bottom, acquires the distance of radar apart from car top, car bottom, well top and pit respectively, calculates the distance of acquireing to obtain the actual position of car.

However, in the process of ascending or descending the elevator car, along with the increase of the distance between the radar and the elevator car, the distance measurement accuracy of the radar is gradually reduced, so that the error of the position of the elevator car obtained through actual measurement is large, and the measurement accuracy of the position of the elevator car is low.

Therefore, the current measuring method of the position of the elevator car has the problem of low measuring accuracy of the position of the elevator car.

Disclosure of Invention

In view of the above, it is necessary to provide an elevator car position determining method, an elevator car position determining device, a computer device, and a storage medium, for solving the technical problem that the measurement accuracy of the elevator car position is low in the above measurement method.

A method of elevator car position determination, the method comprising:

acquiring the switching times of a distance measuring radar arranged on the outer surface of an elevator car for switching a reflector from an initial position, and determining a reflector identifier of a target reflector corresponding to the current moment of the distance measuring radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

obtaining the measurement distance of the current moment obtained by the ranging radar, and obtaining the relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

Determining a current position of the elevator car based on the relative height and the reference distance.

In one embodiment, the step of obtaining a reference distance corresponding to the reflector plate identifier includes:

inquiring a preset database according to the reflecting plate identifier to obtain a plurality of distances between the target reflecting plate and the reference reflecting plate; the preset database stores the distance between every two adjacent reflecting plates;

and adding the plurality of intervals to obtain a reference distance corresponding to the reflecting plate identifier.

In one embodiment, the distance between two adjacent reflection plates is obtained by:

acquiring echo signals of the two adjacent reflecting plates; carrying out fast Fourier transform processing on the echo signals to obtain signal peak values corresponding to the echo signals;

and acquiring the difference value of the distance of the signal peak value corresponding to each echo signal as the distance between every two adjacent reflecting plates.

In one embodiment, the method further comprises:

when the ranging radar receives echo signals from a plurality of reflecting plates, respectively acquiring the signal intensity of the echo signal of each reflecting plate;

Determining a reflecting plate with the maximum signal intensity from the reflecting plates;

generating a control instruction according to the reflecting plate with the maximum signal intensity, and sending the control instruction to the ranging radar; and the control instruction is used for triggering the ranging radar to mark the reflecting plate with the maximum signal intensity as a target reflecting plate.

In one embodiment, the step of obtaining the relative height between the ranging radar and the target reflecting plate according to the measured distance includes:

acquiring an included angle between the range radar and the outer surface of the elevator car;

calculating the product of the measured distance and the cosine value of the included angle as the relative height between the ranging radar and the target reflecting plate;

the step of determining the current position of the elevator car based on the relative height and the reference distance comprises:

acquiring a first vertical distance between the reference reflecting plate and a plane where a top or a pit of the elevator shaft is located, and a second vertical distance between the ranging radar and the bottom or the top of the elevator car;

determining a current position of the elevator car based on the first vertical distance, the second vertical distance, the relative height, and the reference distance.

In one embodiment, after the step of obtaining the measured distance of the current time obtained by the ranging radar, the method further includes:

acquiring a plurality of flat layer distances corresponding to the reflecting plate marks from a database; the leveling distance represents the relative distance between the ranging radar and a target reflecting plate corresponding to each leveling when the elevator car reaches each leveling position;

determining a target flat bed distance equal to the measuring distance from each flat bed distance;

and acquiring a flat floor identification corresponding to the target flat floor distance, and determining the flat floor where the elevator car is located currently according to the flat floor identification.

In one embodiment, the method further comprises:

acquiring each reference flat layer distance of the elevator car at a reference temperature, and acquiring a first distance of the ranging radar relative to a correction reflecting plate at the reference temperature; the correction reflecting plate is arranged on the outer side of the elevator car and is a set distance away from the ranging radar;

acquiring a second distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected;

correcting each leveling distance of the elevator car at the temperature to be corrected according to each reference leveling distance, the first distance and the second distance;

And/or the presence of a gas in the gas,

acquiring the reference distance between every two adjacent reflecting plates at the reference temperature;

and correcting the distance between every two adjacent reflecting plates at the temperature to be corrected according to the reference distance, the first distance and the second distance.

An elevator car position determining apparatus, the apparatus comprising:

the reflecting plate identification determining module is used for acquiring the switching times of the reflecting plate switching of the ranging radar arranged on the outer surface of the elevator car from the initial position and determining the reflecting plate identification of the target reflecting plate corresponding to the current moment of the ranging radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

a relative height acquisition module, configured to acquire a measurement distance at the current time obtained by the ranging radar, and obtain a relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

the reference distance acquisition module is used for acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

And the car position determining module is used for determining the current position of the elevator car according to the relative height and the reference distance.

A computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:

acquiring the switching times of a distance measuring radar arranged on the outer surface of an elevator car for switching a reflector from an initial position, and determining a reflector identifier of a target reflector corresponding to the current moment of the distance measuring radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

obtaining the measurement distance of the current moment obtained by the ranging radar, and obtaining the relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

Determining a current position of the elevator car based on the relative height and the reference distance.

A computer-readable storage medium, on which a computer program is stored which, when executed by a processor, carries out the steps of:

acquiring the switching times of a distance measuring radar arranged on the outer surface of an elevator car for switching a reflector from an initial position, and determining a reflector identifier of a target reflector corresponding to the current moment of the distance measuring radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

obtaining the measurement distance of the current moment obtained by the ranging radar, and obtaining the relative height between the ranging radar and the target reflecting plate according to the measurement distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and a reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft;

determining a current position of the elevator car based on the relative height and the reference distance.

The method, the device, the computer equipment and the storage medium for determining the position of the elevator car can determine the current position of the elevator car by arranging a plurality of reflecting plates on the side wall of an elevator shaft at intervals, installing the ranging radar outside the elevator car, determining the reflecting plate identifier of the target reflecting plate corresponding to the ranging radar according to the switching times of the ranging radar for switching the reflecting plates from the initial position, acquiring the reference distance corresponding to the reflecting plate identifier, acquiring the measurement distance of the ranging radar at the current moment, determining the relative height between the ranging radar and the target reflecting plate according to the measurement distance, and finally determining the current position of the elevator car according to the relative height and the reference distance. The distance measuring radar does not need to measure the distance to the top of a well or a pit all the time, the measuring distance of the distance measuring radar is reduced, the distance measuring precision of the distance measuring radar is guaranteed, the measuring error is reduced through accurate calculation, and the technical problem that the measuring precision is low in the traditional measuring mode is solved.

Drawings

Fig. 1 is a diagram of an application scenario of an elevator car position determination method in one embodiment;

fig. 2 is a schematic flow diagram of a method of determining elevator car position in one embodiment;

fig. 3 is a dimensional explanatory diagram in an elevator car position determining method in one embodiment;

fig. 4 is a graph of distance-amplitude change in a method of determining elevator car position according to one embodiment;

FIG. 5 is a schematic flow chart of the target reflecting plate determining step in one embodiment;

FIG. 6 is a schematic diagram of a target reflector switching process in one embodiment;

FIG. 7 is a schematic view showing the installation position of the correcting reflecting plate in one embodiment;

fig. 8 is a block diagram showing the structure of an elevator car position determining apparatus in one embodiment;

FIG. 9 is a diagram illustrating an internal structure of a computer device according to an embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The method for determining the position of the elevator car can be applied to the application environment shown in fig. 1. The distance measuring radar 102 is arranged on the outer side of the elevator car, and a plurality of reflecting plates are sequentially arranged on the wall of the elevator shaft on the same side as the distance measuring radar 102 at intervals; of course, the radar signal may also be an angle reflector or other objects capable of effectively reflecting the radar signal, and is not particularly limited herein; the reflecting plates are denoted as R1 and R2 … Rn in this order in terms of their mounting positions. The distance between any two adjacent reflecting plates can be recorded as d, the numerical value of the distance d can be determined according to the precision of different ranging radars, and the general range is several meters to dozens of meters. Therein, the range radar 102 communicates with a server 104 over a network. The distance measuring radar 102 may be a millimeter wave radar, and the server 104 may be implemented by an independent server or a server cluster composed of a plurality of servers.

In one embodiment, as shown in fig. 2, there is provided an elevator car position determining method, which is described by taking the method as an example applied to the server 104 in fig. 1, and includes the following steps:

step S202, obtaining the switching times of the distance measuring radar arranged on the outer surface of the elevator car for switching the reflecting plate from the initial position, and determining the reflecting plate identifier of the target reflecting plate corresponding to the current moment of the distance measuring radar according to the switching times; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals.

The initial position may be a position of a reflection plate closest to the top of the elevator hoistway or the pit, that is, a position of the reflection plate R1 or the reflection plate Rn in fig. 1, or may be a position of any reflection plate, and is not particularly limited herein.

The number of times of switching may be the number of times of switching the reflection plate with respect to the initial position when the elevator car reaches the current position from the initial position, that is, the number of reflection plates through which the ranging radar 102 passes when reaching the target reflection plate corresponding to the current time from the initial position.

In a specific implementation, the target reflecting plate of the ranging radar 102 at the current time may be determined according to the number of times of switching the reflecting plate by the ranging radar 102 calculated from the initial position, for example, as shown in fig. 1, when the position of the reflecting plate R1 closest to the top of the elevator hoistway is taken as the initial position, if the elevator car descends from the position of the reflecting plate R1 for the first time and the reflecting plates are switched 3 times in the descending process, it indicates that the ranging radar 102 passes through the reflecting plates R1, R2, R3 and R4 in sequence, the target reflecting plate corresponding to the ranging radar 102 at the current time is the 4 th reflecting plate, and the reflecting plate identifier is R4; for another example, when the position of the reflecting plate Rn closest to the bottom of the elevator shaft is taken as the initial position, the finally obtained switching frequency is the switching frequency of the elevator car relative to the reflecting plate Rn in the running process, if the switching frequency of the reflecting plate switching by the distance measuring radar 102 is 4 times, it indicates that the distance measuring radar 102 passes through the reflecting plates Rn, Rn-1, Rn-2, Rn-3 and Rn-4, and the reflecting plate identifier of the target reflecting plate corresponding to the current time is Rn-4.

In practical application, since the elevator car does not always start to operate from the initial position, and the ascending and descending processes of the elevator car may have been performed for multiple times, the server 104 may respectively obtain the first switching times during the ascending process and the second switching times during the descending process of the elevator car, and make a difference between the first switching times during the ascending process and the second switching times during the descending process to obtain the switching times relative to the initial position, and further determine the reflector identifier of the target reflector corresponding to the current time of the ranging radar 102 according to the switching times and the reflector identifier of the reflector corresponding to the initial position. For example, if the elevator car has ascended and descended a plurality of times, and the second switching frequency for switching the reflectors during descending is 5 times, and the first switching frequency for switching the reflectors during ascending is 3 times, the switching frequency for switching the reflectors by the range radar 102 is 5-3-2 times with respect to the initial position R1, which indicates that the range radar 102 has passed through the reflectors R1 and R2 in sequence, and the target reflector corresponding to the current time is the third reflector, and the reflector identifier thereof is R3.

Similarly, the initial position may also be set to the position of the reflection plate closest to the elevator hoistway pit, that is, the position of Rn, or the position of any other reflection plate, and the process of determining the reflection plate identifier of the target reflection plate at the current moment of the ranging radar 102 according to the switching times is similar to the above process, and is not described again here.

In practical application, can set up backup battery for range radar to when the elevator outage, range radar still can take notes the reflecting plate sign of reflecting plate.

Step S204, obtaining the measuring distance of the current moment obtained by the ranging radar, and obtaining the relative height between the ranging radar and the target reflecting plate according to the measuring distance; the measuring distance is the distance between the ranging radar and the target reflecting plate.

In specific implementation, the distance measuring radar 102 may transmit a radar wave signal to the target reflection plate, receive an echo reflected from the target reflection plate, calculate a measurement distance between the distance measuring radar 102 and the target reflection plate according to a time interval between the transmitted radar signal and the target reflection plate and a propagation speed of the radar signal, and then the server 104 may obtain the measurement distance from the distance measuring radar 102, and determine a relative height between the distance measuring radar and the target reflection plate at the current time according to the measurement distance. As shown in fig. 3, if R2 is used as the target reflection plate, R may represent the measured distance, and h may represent the relative height between the ranging radar and the target reflection plate.

Further, in practical application, radar signals transmitted by the range radar 102 need to be capable of scanning the reflecting plates and receiving echoes from the reflecting plates, so that a certain included angle is formed between the signal transmitting direction of the range radar and the outer surface of the elevator car, and the relative height between the range radar and the target reflecting plate can be determined according to the included angle and the measuring distance. For example, in fig. 3, if the angle is θ, the relative height can be expressed as: h is r cos θ.

Step S206, acquiring a reference distance corresponding to the reflecting plate identifier; the reference distance is a vertical distance between the target reflecting plate and the reference reflecting plate, and the reference reflecting plate is a reflecting plate closest to the bottom pit or the top of the elevator shaft.

In a specific implementation, after the server 104 obtains the reflector identifier of the target reflector, the vertical distance between the target reflector and the reference reflector may be further searched from the database, and the vertical distance is used as the reference distance corresponding to the reflector identifier. For example, in fig. 3, when the reflection plate R1 closest to the top of the elevator shaft is used as the reference reflection plate and R2 is used as the target reflection plate, the reference distance corresponding to the target reflection plate R2 can be represented by H1.

And step S208, determining the current position of the elevator car according to the relative height and the reference distance.

In a specific implementation, after determining the relative height between the ranging radar 102 and the target reflecting plate and determining the vertical distance between the target reflecting plate and the reference reflecting plate, i.e. the reference distance, the server 104 can obtain the position of the ranging radar relative to the reference reflecting plate according to the relative height and the reference distance, and use the position as the current position of the elevator car.

Further, if the installation position of the ranging radar is not parallel to the plane where the top or the bottom of the elevator car is located, the vertical distance of the ranging radar relative to the plane where the top or the bottom of the elevator car is located needs to be obtained, and the current position of the elevator car is determined according to the vertical distance, the relative height and the reference distance.

In the method for determining the position of the elevator car, a plurality of reflecting plates are arranged on the side wall of the elevator shaft at intervals, a distance measuring radar is arranged on the outer side of the elevator car, the reflecting plate identifier of a target reflecting plate corresponding to the distance measuring radar is determined according to the switching times of the distance measuring radar for switching the reflecting plates from the initial position, the reference distance corresponding to the reflecting plate identifier is obtained, the measuring distance of the distance measuring radar at the current moment is obtained, the relative height between the distance measuring radar and the target reflecting plate is determined according to the measuring distance, and finally the current position of the elevator car is determined according to the relative height and the reference distance. The measuring distance of the distance measuring radar is reduced, so that the distance measuring precision of the distance measuring radar is guaranteed, the measuring error is reduced through accurate calculation, and the technical problem that the measuring precision is low in the traditional measuring mode is solved.

In one embodiment, the step of acquiring the reference distance corresponding to the reflector mark in step S206 includes: inquiring a preset database according to the reflecting plate identifier to obtain a plurality of intervals between the target reflecting plate and the reference reflecting plate; the preset database stores the distance between every two adjacent reflecting plates; and adding the plurality of intervals to obtain a reference distance corresponding to the reflecting plate identifier.

In the concrete implementation, after the setting of each reflecting plate is completed, the distance between any adjacent reflecting plates needs to be acquired, and is stored in a database corresponding to the reflecting plate identifier, the storage form of the distance can be (reflecting plates Rn-1 and Sn-1), and the reference distance corresponding to each reflecting plate is the vertical distance between the reflecting plate and the reference reflecting plate. For example, if the reference reflection plate is R1 and the target reflection plate is R3, the distance between the target reflection plate and the reference reflection plate includes: the distance between R1 and R2 is denoted as S1, and the distance between R2 and R3 is denoted as S2, and the reference distance corresponding to the reflector mark of the target reflector R3 is S1+ S2.

Alternatively, after the distance between adjacent reflective plates is obtained, the reference distance corresponding to the reflective plate identifier of each reflective plate may be calculated in advance, and the reflective plate identifier and the reference distance may be directly stored in the database, for example, each reflective plate identifier and the reference distance may be stored in the form of (reflective plate Rn, reference distance Dn), and after the reflective plate identifier of the target reflective plate is determined, the corresponding reference distance may be directly obtained from the preset database according to the reflective plate identifier.

In the embodiment, the distances between the adjacent reflecting plates are stored in the database, after the reflecting plate identification is determined, a plurality of distances between the target reflecting plate and the reference reflecting plate are searched from the database, and the sum of the distances is calculated to serve as the reference distance corresponding to the reflecting plate.

In one embodiment, the distance between two adjacent reflection plates is obtained by: acquiring echo signals of every two adjacent reflecting plates; carrying out fast Fourier transform processing on the echo signals to obtain signal peak values corresponding to the echo signals; and acquiring the difference value of the distances of the signal peak values corresponding to the echo signals, and taking the difference value as the distance between every two adjacent reflecting plates.

In a specific implementation, the distance between adjacent reflection plates may be calculated according to an echo signal received by a ranging radar when an elevator or the ranging radar is initially powered on, specifically, the echo signal of each adjacent reflection plate may be obtained by the ranging radar, and the echo signal from the adjacent reflection plate is processed by Fast Fourier Transform (FFT), an algorithm for calculating discrete fourier transform by using a computer, so as to obtain a distance-amplitude variation graph, as shown in fig. 4, where a distance of a horizontal axis represents a relative distance between the ranging radar and the reflection plate, and an amplitude of a vertical axis represents an intensity of the echo signal, and a signal peak value corresponding to each echo signal is determined from the distance-amplitude variation graph, that is, a signal intensity when the radar signal is completely transmitted to any reflection plate is determined. And when the distance-amplitude change graph determines that the signal intensities from the two adjacent reflecting plates are respectively the maximum, the relative distances between the ranging radar and the two reflecting plates are respectively recorded as a first relative distance d11 and a second relative distance d12, and the difference value of the first relative distance and the second relative distance is obtained to obtain the distance between every two adjacent reflecting plates.

In practical application, because the distance measuring radar and the surface of the elevator car have an included angle (such as a theta angle in fig. 1), when the difference value between the first relative distance and the second relative distance is obtained, the included angle between the distance measuring radar and the surface of the elevator car needs to be obtained, the product of the difference value and the cosine value of the included angle theta is calculated, the distance between every two adjacent reflecting plates can be obtained, and the calculation process can be expressed by a formula as follows: (d11-d12) cos θ.

Alternatively, the distance between two adjacent reflection plates may be obtained by directly measuring the distance between the adjacent reflection plates by a measuring device (such as a high-precision measuring instrument) after the reflection plates are completely set.

In this embodiment, through obtaining the echo signal of adjacent reflecting plate, obtain the signal peak that each echo signal corresponds after carrying out fast fourier transform to echo signal, obtain the interval of adjacent reflecting plate according to the difference of signal peak to after confirming the reflecting plate sign, confirm the reference distance that corresponds with the reflecting plate sign according to the interval between the adjacent reflecting plate, further confirm the position of elevator car.

In one embodiment, the method for determining the position of the elevator car further comprises the step of determining a target reflecting plate, and specifically comprises the following steps:

step S502, when the ranging radar receives echo signals from a plurality of reflecting plates, respectively acquiring the signal intensity of the echo signal of each reflecting plate;

step S504, determining a reflecting plate with the maximum signal intensity from all the reflecting plates;

step S506, generating a control instruction according to the reflecting plate with the maximum signal intensity, and sending the control instruction to the ranging radar; and the control command is used for triggering the ranging radar to mark the reflecting plate with the maximum signal intensity as a target reflecting plate.

In a specific implementation, in the process of switching the target reflecting plate, the ranging radar receives echo signals from the plurality of reflecting plates, and at this time, the target reflecting plate can be determined from the plurality of reflecting plates according to the echo signals from the respective reflecting plates. More specifically, after the ranging radar receives echo signals from all the reflecting plates, the signal intensity of each echo signal is determined firstly, the signal intensities are compared, the reflecting plate with the maximum signal intensity is determined from all the reflecting plates, a control command is generated according to the reflecting plate with the maximum signal intensity, and the control command is sent to the ranging radar so as to trigger the ranging radar to identify the reflecting plate with the maximum signal intensity as a target reflecting plate.

For example, as shown in fig. 6, in order to schematically illustrate the process of switching the target reflecting plate by the ranging radar, assuming that the elevator car is in the ascending process, the radar signal is irradiated on the reflecting plate R2 from the beginning and is gradually and completely irradiated on the reflecting plate R2, the irradiation range on the reflecting plate R2 is gradually reduced and the irradiation range on the reflecting plate R1 is gradually increased along with the ascending of the elevator car until the radar signal is completely irradiated on the reflecting plate R1. The signal strength of the reflector plate R1 received by the range radar is A in the switching process _R1The signal intensity on the reflection plate R2 is A_R2During the ascending of the elevator car, when A_R2>A_R1When the signal intensity is the maximum, the reflector R1 is used as the target reflector; when A is_R2<A_R1At this time, the target reflecting plate of the range radar is switched from R2 to R1.

In this embodiment, through the signal strength who obtains the echo signal from different reflecting plates, compare each signal strength, confirm the biggest reflecting plate of signal strength to steerable range radar is the target reflecting plate with the biggest reflecting plate sign of signal strength, carries out the switching of target reflecting plate with control range radar.

In one embodiment, the step of obtaining the relative height between the ranging radar and the target reflection plate according to the measured distance in step S204 includes: acquiring an included angle between a distance measuring radar and the outer surface of an elevator car; and calculating the product of the measured distance and the cosine value of the included angle as the relative height between the ranging radar and the target reflecting plate.

In the concrete implementation, because in practical application, the signal emission direction of the range radar 102 and the side surface of the elevator car form an included angle, after the measurement distance between the range radar and the target reflecting plate is determined, the included angle between the range radar and the outer surface of the elevator car can be obtained first, and the relative height between the range radar and the target reflecting plate is obtained by calculating the product of the measurement distance and the cosine value of the included angle.

Alternatively, the relative height between the ranging radar and the target reflecting plate can be determined according to the horizontal distance and the measured distance by acquiring the horizontal distance between the ranging radar and the side wall of the hoistway, for example, in fig. 3, k represents the horizontal distance, r represents the measured distance, and then the relative height between the ranging radar and the target reflecting plate

In one embodiment, the step of determining the current position of the elevator car according to the relative height and the reference distance in step S208 includes: acquiring a first vertical distance between a reference reflecting plate and a plane where a top or a bottom pit of an elevator shaft is located, and a second vertical distance between a ranging radar and the bottom or the top of an elevator car; and determining the absolute position of the elevator car in the hoistway according to the first vertical distance, the second vertical distance, the relative height and the reference distance.

In the specific implementation, when the distance measuring radar and the top or the bottom of the elevator car are not on the same plane, and the reference reflecting plate and the top or the pit of the elevator shaft are not on the same plane, before determining the current position of the elevator car, the server needs to obtain a first vertical distance between the reference reflecting plate and the plane where the top or the pit of the elevator shaft is located and a second vertical distance between the distance measuring radar and the bottom or the top of the elevator car, and the absolute position of the elevator car in the elevator shaft is determined according to the first vertical distance, the second vertical distance, the relative height and the reference distance. In fig. 3, for example, the second vertical distance is denoted by D, the first vertical distance is denoted by H0, the relative height is denoted by H, the target reflecting plate is R2, and the reference reflecting plate is R1, so that the reference distance D1 is H1, and the distance L between the bottom of the elevator car and the top of the hoistway is H0+ H1+ H + D.

If the distance between the top of the elevator car and the top/pit of the hoistway is calculated, the second vertical distance may be the distance between the ranging radar and the top of the elevator car, and if d 'is the second vertical distance, the distance L between the top of the elevator car and the top of the hoistway is H0+ H1+ H-d' in fig. 3.

In the above embodiment, the absolute position of the elevator car in the hoistway can be determined by obtaining the included angle between the distance measuring radar and the outer surface of the elevator car, obtaining the first vertical distance between the reference reflection plate and the plane where the top or pit of the elevator hoistway is located, and obtaining the second vertical distance between the distance measuring radar and the bottom or the top of the elevator car, calculating the relative height according to the included angle, and further according to the first vertical distance, the second vertical distance, the relative height and the reference distance, so that the elevator car is controlled according to the obtained absolute position of the elevator car.

In one embodiment, after the step of obtaining the measured distance of the current time obtained by the ranging radar, the method further includes: acquiring a plurality of flat layer distances corresponding to the reflecting plate marks from a database; the leveling distance represents the relative distance between the ranging radar and the target reflecting plate corresponding to each leveling when the elevator car reaches each leveling position; determining a target flat bed distance equal to the measurement distance from each flat bed distance; and acquiring a flat floor identification corresponding to the target flat floor distance, and determining the current flat floor of the elevator car according to the flat floor identification.

In a specific implementation, each flat layer has one corresponding reflection plate, and multiple flat layers can correspond to the same reflection plate, so each reflection plate can be a target reflection plate with multiple flat layer distances, and the reflection plate identifier of each reflection plate and the corresponding multiple flat layer distances can be correspondingly stored in a database, for example, in the form of (reflection plate Rn, flat layer distances: dn1, dn2, dn 3). After the measuring distance between the distance measuring radar and the target reflecting plate at the current moment is obtained through the distance measuring radar, a plurality of flat layer distances corresponding to the reflecting plate identification of the target reflecting plate are screened out from a database, the measuring distances are compared with the flat layer distances respectively, whether the measuring distances are equal to one of the flat layer distances or not is determined, when the flat layer distances equal to the measuring distances are determined from the flat layer distances, the flat layer distances are used as the target flat layer distances, the flat layer identifications corresponding to the target flat layer distances are obtained, and the flat layer where the elevator car is located at present is determined. For example, if the measured distance at the current time is equal to the flat bed distance of the 9 th floor, the corresponding flat bed identifier is 9, and the flat bed where the elevator car is currently located is determined to be the 9 th floor.

Further, the server generates a corresponding control command according to the current flat floor where the elevator car is located, sends the control command to the elevator controller, and controls the elevator car to move through the elevator controller, for example, when a stopping command that the elevator stops at a certain flat floor is received, the obtained measurement distance is equal to the flat floor distance corresponding to the flat floor, and the obtained reflecting plate identifier is the same as the reflecting plate identifier corresponding to the flat floor, so that the elevator car is controlled to stop at the current flat floor.

In this embodiment, a plurality of flat bed distances corresponding to the reflecting plate identifiers are obtained from the database, the measurement distance at the current moment is compared with each flat bed distance, a target flat bed distance equal to the measurement distance is determined, the flat bed identifier of the target flat bed distance is obtained, and the flat bed where the elevator car is currently located is determined, so that the motion of the elevator car can be controlled according to the flat bed distance.

In one embodiment, the method further comprises: acquiring each reference flat layer distance of the elevator car at a reference temperature, and acquiring a first distance of the ranging radar relative to the correction reflecting plate at the reference temperature; the correction reflecting plate is arranged on the outer side of the elevator car and is a set distance away from the ranging radar; acquiring a second distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected; and correcting each flat layer distance of the elevator car at the temperature to be corrected according to each reference flat layer distance, the first distance and the second distance.

The correcting and reflecting plate is used for correcting the flat bed distance of the elevator car at different temperatures.

It is understood that due to the temperature change, the building may have thermal barrier shrinkage phenomenon, resulting in a change in actual position (e.g., actual flat position of each floor, and a distance between adjacent reflective plates). The linear expansion coefficient of common steel and concrete is 10 multiplied by 10^ -6, and for a 100-meter tall building, the influence of temperature change is large when the temperature changes by 1 ℃, the actual position changes by 1mm, the temperature changes by 30 ℃ and the actual position changes by 30mm, so that the temperature compensation correction is needed.

In concrete realization, the correction reflecting plate can be installed outside the elevator car and at a position away from the ranging radar by a set distance, and the correction reflecting plate only needs to reflect weak radar signals and the ranging radar can detect the weak radar signals. When temperature compensation correction is carried out, the server can acquire the flat distance of each floor at the reference temperature as the reference flat distance, acquire the distance of the ranging radar relative to the correction reflecting plate at the reference temperature and record the distance as a first distance, and acquire the distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected and record the distance as a second distance when the temperature changes. Because the expansion with heat and contraction with cold of steel, concrete are with the temperature linear correlation, consequently, can utilize its and the distance deviation between the correction reflecting plate that the range radar acquireed to carry out the correction to the flat bed distance of treating each floor under the temperature of correcting. The elevator car leveling distance is recorded as the leveling distance to be corrected under the temperature to be corrected according to the reference leveling distances, the first distance under the reference temperature and the second distance under the temperature to be corrected. Wherein, the correction process of each flat layer distance to be corrected can be expressed by a relational expression as follows:

For example, as shown in FIG. 7, the installation of the temperature correction reflecting plate is schematically illustrated, and the correction reflecting plate is installed at a distance ranging radar D_OAt a position where a relative distance between the ranging radar and the correcting reflection plate measured under a certain reference temperature condition (e.g., 25 ℃) is assumed to be D_O(25 ℃), the reference flat floor distance corresponding to each floor is d_nm(25 ℃ C.). The relative distance measured between the range radar and the correcting reflecting plate is D at the temperature to be corrected (for example, 15 ℃), and_O(15 ℃) can be used for calculating the flat-bed distance d of each floor at the temperature (15 ℃) to be corrected according to the relational expression_nmThe computational expression (15 ℃) is:

further, in another embodiment, after acquiring a first distance of the ranging radar relative to the correction reflecting plate at the reference temperature and acquiring a second distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected, the reference distance between every two adjacent reflecting plates at the reference temperature can be acquired; and correcting the distance between every two adjacent reflecting plates at the temperature to be corrected according to the reference distances, the first distance and the second distance.

The distance between every two adjacent reflecting plates can be corrected by the correcting reflecting plates, in the concrete implementation, the distance between every two adjacent reflecting plates at the reference temperature can be acquired and used as the reference distance, and the distance deviation between the correcting reflecting plates and the distance acquired by the ranging radar can be used for correcting the distance between the adjacent reflecting plates at the temperature to be corrected. That is, the distance between adjacent reflective plates at the temperature to be corrected can be calculated according to the reference distance, the first distance at the reference temperature and the second distance at the temperature to be corrected, and the distance is recorded as the distance to be corrected. The correction process of each distance to be corrected can be expressed by the following relational expression:

According to the relational expression of the to-be-corrected flat bed distance and the relational expression of the to-be-corrected interval, after the first distance, the second distance and the reference flat bed distance of each floor are obtained or the first distance, the second distance and the reference interval between adjacent reflecting plates are obtained, the to-be-corrected flat bed distance corresponding to each floor or the to-be-corrected interval between adjacent reflecting plates at the to-be-corrected temperature can be obtained through calculation.

In the above embodiment, the influence of temperature change on the flat bed distance of the elevator car and the distance between the adjacent reflecting plates is considered, and the temperature compensation method is adopted to correct the flat bed distance of each floor of the elevator car and the distance between the adjacent reflecting plates at the temperature to be corrected, so as to avoid the problem that the actual position of the elevator changes due to the influence of temperature, and the uncorrected flat bed position is still adopted to control the action of the elevator car, so that potential safety hazards exist, or the uncorrected reflecting plate distance is adopted to determine the position of the elevator car, so that the calculation result has the problems of larger deviation and inaccurate result.

It should be noted that, this application does not do specifically and restricts the interval of two liang of adjacent reflecting plates, the contained angle of range radar and elevator car surface, also does not have higher required precision, because range radar is after the installation is accomplished, the contained angle is generally just fixed unchangeable, consequently, this application only restricts elevator car at the operation in-process, the radar signal of range radar transmission can keep hitting on the reflecting plate always, range radar can measure always promptly with arbitrary one reflecting plate or arbitrary two adjacent reflecting plate between the distance can.

It should be understood that although the steps in the flowcharts of fig. 2 and 5 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 2 and 5 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performing the sub-steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least some of the sub-steps or stages of other steps.

In one embodiment, as shown in fig. 8, there is provided an elevator car position determining apparatus including: a reflector identification determination module 802, a relative height acquisition module 804, a reference distance acquisition module 806, and a car position determination module 808, wherein:

the reflecting plate identifier determining module 802 is configured to obtain the number of times for switching the reflecting plate from an initial position by the ranging radar installed on the outer surface of the elevator car, and determine the reflecting plate identifier of the target reflecting plate corresponding to the current time of the ranging radar according to the number of times for switching; the reflecting plates are sequentially arranged on the side wall of the elevator shaft at intervals;

A relative height obtaining module 804, configured to obtain a measured distance at the current time obtained by the ranging radar, and obtain a relative height between the ranging radar and the target reflecting plate according to the measured distance; the measured distance is the distance between the ranging radar and the target reflecting plate;

a reference distance obtaining module 806, configured to obtain a reference distance corresponding to the reflector identifier; the reference distance is the vertical distance between the target reflecting plate and the reference reflecting plate, and the reference reflecting plate is the reflecting plate closest to the bottom pit or the top of the elevator shaft;

a car position determination module 808 configured to determine a current position of the elevator car based on the relative height and the reference distance.

In an embodiment, the reference distance obtaining module 806 is specifically configured to: inquiring a preset database according to the reflecting plate identifier to obtain a plurality of intervals between the target reflecting plate and the reference reflecting plate; the preset database stores the distance between every two adjacent reflecting plates; and adding the plurality of intervals to obtain a reference distance corresponding to the reflecting plate identifier.

In one embodiment, the above apparatus further comprises:

the echo signal acquisition module is used for acquiring echo signals of every two adjacent reflecting plates; carrying out fast Fourier transform processing on the echo signals to obtain signal peak values corresponding to the echo signals;

And the distance difference value acquisition module is used for acquiring the difference value of the distances of the signal peak values corresponding to the echo signals, and the difference value is used as the distance between every two adjacent reflecting plates.

In one embodiment, the above apparatus further comprises:

the signal intensity acquisition module is used for respectively acquiring the signal intensity of the echo signal of each reflecting plate when the ranging radar receives the echo signal from the plurality of reflecting plates;

the reflecting plate determining module is used for determining the reflecting plate with the maximum signal intensity from all the reflecting plates;

the control instruction generating module is used for generating a control instruction according to the reflecting plate with the maximum signal intensity and sending the control instruction to the ranging radar; and the control command is used for triggering the ranging radar to mark the reflecting plate with the maximum signal intensity as a target reflecting plate.

In an embodiment, the relative height obtaining module 804 is specifically configured to: acquiring an included angle between a distance measuring radar and the outer surface of an elevator car; calculating the product of the measured distance and the cosine value of the included angle as the relative height between the ranging radar and the target reflecting plate;

the car position determination module 808 is specifically configured to: acquiring a first vertical distance between a reference reflecting plate and a plane where a top or a bottom pit of an elevator shaft is located, and a second vertical distance between a ranging radar and the bottom or the top of an elevator car; and determining the absolute position of the elevator car in the hoistway according to the first vertical distance, the second vertical distance, the relative height and the reference distance.

In one embodiment, the above apparatus further comprises:

the leveling distance acquisition module is used for acquiring a plurality of leveling distances corresponding to the reflecting plate identifiers from the database; the leveling distance represents the relative distance between the ranging radar and the target reflecting plate corresponding to each leveling when the elevator car reaches each leveling position;

the target flat bed distance determining module is used for determining a target flat bed distance equal to the measuring distance from all the flat bed distances;

and the leveling identifier acquisition module is used for acquiring a leveling identifier corresponding to the target leveling distance and determining the current leveling of the elevator car according to the leveling identifier.

In one embodiment, the above apparatus further comprises:

the first distance acquisition module is used for acquiring each reference flat layer distance of the elevator car at a reference temperature and acquiring a first distance of the ranging radar relative to the correction reflecting plate at the reference temperature; the correction reflecting plate is arranged on the outer side of the elevator car and is a set distance away from the ranging radar;

the second distance acquisition module is used for acquiring a second distance of the ranging radar relative to the correction reflecting plate at the temperature to be corrected;

the distance correction module is used for correcting each flat layer distance of the elevator car at the temperature to be corrected according to each reference flat layer distance, the first distance and the second distance; and/or the presence of a gas in the gas,

The distance acquisition module is used for acquiring the reference distance between every two adjacent reflecting plates at the reference temperature;

and the distance correction module is used for correcting the distance between every two adjacent reflecting plates at the temperature to be corrected according to the reference distances, the first distance and the second distance.

It should be noted that, the elevator car position determining apparatus of the present application corresponds to the elevator car position determining method of the present application one to one, and the technical features and the advantages thereof described in the above embodiment of the elevator car position determining method are all applicable to the embodiment of the elevator car position determining apparatus, and specific contents may refer to the description in the embodiment of the method of the present application, and are not described herein again, and thus, the description is hereby made.

Further, each module in the above-described elevator car position determining apparatus may be implemented in whole or in part by software, hardware, and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as shown in fig. 9. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer device is used to store data generated during the determination of the position of the elevator car. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement an elevator car position determination method.

Those skilled in the art will appreciate that the architecture shown in fig. 9 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is further provided, which includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method embodiments when executing the computer program.

In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.