阅读说明：本技术 室内物料监管装置 (Indoor material supervision device ) 是由 袁强 于 2021-10-09 设计创作，主要内容包括：本发明提出一种室内物料监管装置,包括：物料三维扫描系统和智能体积测量及告警处理系统；物料三维扫描系统包括：激光雷达模块、索道滑车模块、电动滑轨模块、无线供电模块、无线数据传输模块；智能体积测量及告警处理系统包括：智能处理模块、网络传输模块。本发明具有全自动物料堆体测量、测量无死角,精度高及报警及时的特点,大大降低了人工带来的不确定性及监测的成本。(The invention provides an indoor material supervision device, which comprises: a material three-dimensional scanning system and an intelligent volume measurement and alarm processing system; the material three-dimensional scanning system includes: the system comprises a laser radar module, a cableway pulley module, an electric slide rail module, a wireless power supply module and a wireless data transmission module; the intelligent volume measurement and alarm processing system comprises: intelligent processing module, network transmission module. The invention has the characteristics of full-automatic material pile body measurement, no dead angle in measurement, high precision and timely alarm, and greatly reduces the uncertainty and monitoring cost caused by manpower.)

1. An indoor material supervision device, comprising: a material three-dimensional scanning system and an intelligent volume measurement and alarm processing system;

the three-dimensional scanning system of material includes: the system comprises a laser radar module, a cableway pulley module, an electric slide rail module, a wireless power supply module and a wireless data transmission module; the first wireless transmission module and the laser radar module of the wireless data transmission module are arranged on the cableway pulley module; the cableway pulley module is arranged on the electric sliding rail module; the wireless power supply module provides electric energy for the laser radar module, the cableway pulley module and the first wireless transmission module; the wireless charging transmitting device of the wireless power supply module is arranged on the electric sliding rail module;

the intelligent volume measurement and alarm processing system comprises: the system comprises an intelligent processing module used for calculating the volume of the material and sending a control command, and a network transmission module used for transmitting the command and receiving signals for the intelligent processing module.

2. The indoor material supervision device according to claim 1, characterized in that the cableway trolley module comprises an electric trolley and a cableway carrying the electric trolley; the cableway pulley module is used for driving the laser radar module and the first wireless transmission module to do reciprocating linear motion on the cableway.

3. The indoor material supervising device according to claim 2, wherein said electric sliding rail module is erected on both sides of the indoor ceiling, each side is installed with a sliding rail, a pulley moving on said sliding rail and a motor driving said pulley to move; and two ends of the cableway pulley module are respectively fixed on the two pulleys, and the cableway is pulled by the two pulleys and keeps straight.

4. The indoor material supervision apparatus of claim 1, wherein the wireless power supply module comprises: a power supply battery and a wireless charging and transmitting device are used for supplying electric energy to the laser radar module, the cableway pulley module and the first wireless transmission module; the wireless charging transmitting device is arranged on a slide rail at one end of the electric slide rail module; the power supply battery is arranged on the cableway pulley module; the wireless charging transmitting device is powered by an external power supply; the power supply battery is provided with a wireless charging receiving device, and the power supply battery is wirelessly charged by receiving the magnetic induction signal sent by the wireless charging transmitting device.

5. The indoor material supervision apparatus of claim 1, wherein the wireless data transmission module comprises a first wireless transmission module, a second wireless transmission module, a third wireless transmission module; the first wireless transmission module is used for transmitting point cloud data acquired by the laser radar module and controlling an instruction of the electric tackle in the cableway tackle module to move; the second wireless transmission module is used for transmitting a control instruction of a motor which is arranged on the slide rail on one side of the electric slide rail module and drives the pulley to move; the third wireless transmission module is used for transmitting a control instruction of a motor which drives the pulley to move on the slide rail on the other side of the electric slide rail module.

6. The indoor material supervision device according to claim 1, wherein the intelligent processing module calculates and outputs a material volume calculation result according to the point cloud data collected by the lidar module, calculates a material volume difference according to historical material volume data, and outputs the material volume difference and alarm information to the network transmission module; the intelligent processing module controls the motion of the electric pulley and controls two slide rail motors in the electric slide rail module to rotate simultaneously so as to control the motion of the pulley.

7. The indoor material supervision device according to claim 1, wherein the network transmission module receives the point cloud data, transmits a motion command for controlling the cableway pulley module, and transmits a motion command for controlling two slide rail motors in the electric slide rail module; and simultaneously, the network transmission module sends a material volume calculation result and alarm information which are calculated by the intelligent processing module to a cloud user.

8. The indoor material supervision apparatus of claim 1, wherein the intelligent processing module comprises: a B spline curve fitting calculation module and a point cloud data noise elimination module;

the B spline curve fitting calculation module is used for calculating an envelope curve of a section of the indoor material stack in the vertical direction;

and the point cloud data noise elimination module eliminates the noise of the point cloud data by adopting a mode of combining a point cloud matching algorithm with the physical position and the angle matching of the point cloud according to the overlapping area of the point cloud data.

Technical Field

The invention relates to the field of stack measurement and quantity change monitoring and alarming, in particular to an indoor material supervision device.

Background

In the warehousing industry, the accuracy of the quantity of the stored goods such as grains, ores, materials and the like in the warehouse is the most important issue for enterprises and customers. With the rapid development of the warehouse logistics industry, the stored goods are frequently changed due to the frequent warehouse entry and exit. Related enterprises are increasingly concerned about whether the quantity of goods is accurate or not and whether the loss phenomenon occurs or not. For this reason, the warehousing enterprises spend a great deal of manpower, material resources and financial resources to ensure the safety of the goods. Usually, enterprises hire full-time staff to watch the warehoused goods for 24 hours in turn; or a camera is additionally arranged in the warehouse to remotely monitor the condition of the warehouse. Although the methods have the effect of monitoring the quantity of the goods to a certain extent, the method has huge expenditure, and loopholes of goods supervision still occur due to factors such as fatigue or relaxed vigilance of people and the fact that a monitoring camera cannot monitor a large warehouse or an uneven material surface without dead angles.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an indoor material supervision device.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

the invention provides an indoor material supervision device, which comprises: a material three-dimensional scanning system and an intelligent volume measurement and alarm processing system;

the material three-dimensional scanning system includes: the system comprises a laser radar module, a cableway pulley module, an electric slide rail module, a wireless power supply module and a wireless data transmission module; a first wireless transmission module and a laser radar module of the wireless data transmission module are arranged on the cableway pulley module; the cableway pulley module is arranged on the electric sliding rail module; the wireless power supply module is used for providing electric energy for the laser radar module, the cableway pulley module and the first wireless transmission module; the wireless charging transmitting device of the wireless power supply module is arranged on the electric sliding rail module;

the intelligent volume measurement and alarm processing system comprises: the intelligent processing module is used for calculating the volume of the material and sending out a control command, and the network transmission module is used for transmitting the command and receiving signals for the intelligent processing module.

Preferably, the cableway pulley module comprises an electric pulley and a cableway for bearing the electric pulley; the cableway pulley module is used for driving the laser radar module and the first wireless transmission module to do reciprocating linear motion on the cableway.

Preferably, the electric slide rail modules are erected at two sides of the indoor shed roof, and each side is provided with a slide rail, a pulley moving on the slide rail and a motor driving the pulley to move; the two ends of the cableway pulley module are respectively fixed on the two pulleys, and the cableway is pulled by the two pulleys and keeps straight.

Preferably, the wireless power supply module includes: a power supply battery and a wireless charging and transmitting device are used for supplying electric energy to the laser radar module, the cableway pulley module and the first wireless transmission module; the wireless power supply module is arranged on a slide rail at one end of the electric slide rail module; the power supply battery is arranged on the cableway pulley module; the wireless charging transmitting device is powered by an external power supply; the power supply battery is provided with a wireless charging receiving device, and the power supply battery is wirelessly charged by receiving the magnetic induction signal sent by the wireless charging transmitting device.

Preferably, the wireless data transmission module comprises a first wireless transmission module, a second wireless transmission module and a third wireless transmission module; the first wireless transmission module is used for transmitting point cloud data acquired by the laser radar module and an instruction for controlling the movement of the electric tackle in the cableway tackle module; the second wireless transmission module is used for transmitting a control instruction of a motor which drives the pulley to move on the slide rail at one side of the electric slide rail module; and the third wireless transmission module is used for transmitting a control instruction of a motor for driving the pulley to move on the slide rail on the other side of the electric slide rail module.

Preferably, the intelligent processing module calculates and outputs a material volume calculation result according to the point cloud data acquired by the laser radar module, calculates a material volume difference according to historical material volume data, and outputs the material volume difference and alarm information to the network transmission module; the intelligent processing module controls the motion of the electric pulley and controls two sliding rail motors in the electric sliding rail module to rotate simultaneously so as to control the motion of the pulley.

Preferably, the network transmission module receives the point cloud data, transmits and controls the motion instruction of the cableway pulley module, and transmits and controls the motion instruction of two slide rail motors in the electric slide rail module; and meanwhile, the network transmission module sends a material volume calculation result and alarm information which are calculated by the intelligent processing module to a cloud user.

Preferably, the intelligent processing module comprises: a B spline curve fitting calculation module and a point cloud data noise elimination module; the B spline curve fitting calculation module is used for calculating an envelope curve of a section of the indoor material stack in the vertical direction; and the point cloud data noise elimination module eliminates the noise of the point cloud data by adopting a mode of combining a point cloud matching algorithm with the physical position and angle matching of the point cloud according to the overlapping area of the point cloud data.

The invention can obtain the following technical effects:

the invention has the characteristics of full-automatic material pile body measurement, no dead angle in measurement, high precision and timely alarm, and greatly reduces the uncertainty and monitoring cost caused by manpower.

Drawings

FIG. 1 is a block diagram of an indoor material monitoring apparatus according to an embodiment of the present invention;

FIG. 2 is a functional diagram of various modules in an indoor material monitoring apparatus according to an embodiment of the present invention;

FIG. 3 is a flow chart of an intelligent processing module controlling other modules to collect material pile point cloud data according to an embodiment of the invention;

FIG. 4 is a flow chart of intelligent processing module point cloud data calculation according to an embodiment of the invention.

Wherein the reference numerals include: the system comprises a material three-dimensional scanning system 1, a pulley 101, an electric slide rail module 102, a second wireless transmission module 103, a first wireless transmission module 104, a cableway pulley module 105, a laser radar module 106, a wireless power supply module 107, a third wireless transmission module 108, a network 2, an intelligent volume measurement and alarm processing system 3, a network transmission module 301 and an intelligent processing module 302.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same blocks. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

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

The specific operation of the present invention will be described in detail with reference to fig. 1 to 4:

FIG. 1 shows a specific structure of an indoor material supervision device;

FIG. 2 illustrates the function of various modules in an indoor material monitoring apparatus;

as shown in fig. 1 and fig. 2, the present invention provides an indoor material monitoring device, including: the system comprises a material three-dimensional scanning system 1 and an intelligent volume measurement and alarm processing system 3;

the material three-dimensional scanning system 1 includes: the system comprises a laser radar module 106, a cableway pulley module 105, an electric slide rail module 102, a wireless power supply module 107 and a wireless data transmission module;

the intelligent volume measurement and alarm processing system 3 includes: intelligent processing module 302, network transmission module 301. Setting the direction parallel to the cableway as the direction of an x axis; the direction parallel to the slide rail is set as the y-axis direction.

The detailed description of each component module of the indoor material supervision device is as follows:

the laser radar module 106 mainly scans the surface of the material stack to quickly, massively and accurately acquire three-dimensional information of the surface of the material. The laser radar collects a piece of linear point cloud data of the material surface at the current scanning position in real time, and sends the collected point cloud data to the intelligent volume measurement and alarm processing system 3 through the first wireless transmission module 104.

The cableway pulley module 105 mainly functions to drive the laser radar module 106 and the first wireless transmission module 104 to make reciprocating linear motion on the cableway, so as to obtain the point cloud information of the material pile. The cableway pulley module 105 includes an electric pulley and a cableway carrying the electric pulley.

The electric slide rail modules 102 are erected at two sides of an indoor ceiling, and each side is provided with a slide rail, a pulley 101 moving on the slide rail and a motor driving the pulley 101 to move; the two ends of the cableway pulley module 105 are respectively fixed on the two pulleys 101, and the cableway is pulled by the two pulleys 101 and keeps straight. In order to ensure the straightness of the cableway, the cableway is pulled by adopting a sliding rail mode. Other ways of carrying the cableway, such as racks, etc., can also be adopted. Since the warehouse for storing materials is large in both the length direction and the width direction and the stacking surface of the materials is not flat, the electric slide rail module 102 needs to be installed to ensure that the lidar module 106 carried by the cableway pulley module 105 can scan all positions of the warehouse. The motorized trolley module 102 may be omitted when the surface of the material in the warehouse is relatively flat and all locations of the warehouse can be scanned by the lidar module 106 carried by the cableway trolley module 105 alone.

Due to the large area of the warehouse, cables hundreds of meters long need to be dragged to work together in order to avoid power consumption of the laser radar module 106, the cableway pulley module 105 and the wireless data transmission module. The invention designs a power supply module adopting wireless charging. The wireless power supply module 107 includes: a power supply battery and a wireless charging and transmitting device which are shared by the laser radar module 106, the cableway pulley module 105 and the first wireless transmission module 104; the wireless charging transmitting device is arranged on a slide rail at one end of the electric slide rail module 102; the power supply battery is arranged on the cableway pulley module 105; the wireless charging transmitting device is powered by an external power supply; the power supply battery is provided with a wireless charging receiving device, and the power supply battery is wirelessly charged by receiving the magnetic induction signal sent by the wireless charging transmitting device.

The wireless data transmission module comprises a first wireless transmission module 104, a second wireless transmission module 103 and a third wireless transmission module 108; the first wireless transmission module 104 is used for transmitting point cloud data acquired by the laser radar module 106 and an instruction for controlling the movement of the electric trolley in the cableway trolley module 105; the second wireless transmission module 103 is used for transmitting a control instruction of a motor which drives the pulley 101 to move on a slide rail on one side of the electric slide rail module 102; the third wireless transmission module 108 is configured to transmit a control instruction of a motor that drives the sled 101 to move on a rail on the other side of the electric rail module 102.

The intelligent volume measurement and alarm processing system 3 controls the material three-dimensional scanning system 1 through the network 2, and transmits the material volume difference and alarm information to the cloud user through the network 2.

The intelligent volume measurement and alarm processing system 3 receives the linear point cloud data, forms a three-dimensional space point cloud sequence according to the movement speed of the cableway pulley module 105, adopts invalid point elimination, point cloud matching and point cloud splicing methods to obtain effective material point cloud data, utilizes curved surface integration to obtain material volume, calculates material volume difference according to historical material volume data, and then outputs the material volume difference and alarm information to the network transmission module 301; the intelligent processing module 302 controls the movement of the electric trolley and controls two slide rail motors in the electric slide rail module 102 to rotate simultaneously, so as to control the movement of the trolley 101.

The network transmission module 301 receives the point cloud data, transmits and controls the motion instruction of the cableway pulley module 105 and transmits and controls the motion instruction of two slide rail motors in the electric slide rail module 102 through the network 2; meanwhile, the network transmission module 301 sends the material volume calculation result and the alarm information calculated by the intelligent processing module 302 to the cloud user through the network 2.

The intelligent processing module comprises: a B-spline curve fitting calculation module and a point cloud data noise elimination module.

And the B-spline curve fitting calculation module is used for calculating an envelope curve of the section of the indoor material stack in the vertical direction. And the B-spline curve fitting calculation module calculates an envelope curve of a section of the indoor material stack in the vertical direction by adopting a B-spline curve fitting method (the prior art) according to the point cloud data at the same position of the x axis. And then, calculating the surrounding area of the curve at the section according to the enveloping curve, and further, obtaining the specific volume of the warehouse material pile according to the product of the sum of the area of the sections calculated at each position and the distance of each section.

And the point cloud data noise elimination module eliminates the noise of the point cloud data by adopting a mode of combining a point cloud matching algorithm with the physical position and angle matching of the point cloud according to the overlapping area of the point cloud data.

The sampling interval set by sampling is usually smaller than the scanning coverage radius of the laser radar, so that the obtained point cloud data has an overlapping area, and the point cloud data noise elimination module adopts a mode of combining a point cloud matching algorithm with a point cloud physical position and point cloud angle matching to eliminate the noise of the point cloud data and reduce the influence of point cloud data inaccuracy on volume calculation caused by mechanical motion position errors.

The point cloud data noise elimination module removes measurement noise points from the point cloud data using statistical analysis techniques. And (4) performing statistical analysis on the neighborhood of each point, and removing neighborhood points which do not accord with a certain standard.

Specifically, the method comprises the following steps: the point cloud data noise elimination module firstly respectively calculates the average distance from each point to all adjacent points according to Gaussian distribution, and calculates to obtain a mean value mu and a standard deviation sigma; and finally, regarding the points with the neighborhood distance larger than mu + stdmul sigma in the set of the neighborhood points as noise points, and removing the noise points from the point cloud data. (stdmul represents a threshold for multiples of standard deviation, which can be specified by itself)

In one embodiment of the invention, stdmul in the point cloud data noise elimination module is set to 3.

The specific working process of the point cloud data noise elimination module is as follows: the method comprises the steps of extracting collected point cloud data covered at the same position of the y axis, iteratively accumulating the point cloud data of the y axis and the point cloud data of the y axis, obtaining the position with the minimum sum of errors, namely the coincident position of scanning twice at the same position, calculating the point cloud average value at the coincident position after noise points are removed, ensuring the accuracy and reliability of the obtained point cloud data, and improving the accuracy of material volume calculation.

The process of the intelligent processing module 302 controlling the laser radar module 106, the cableway pulley module 105 and the electric slide rail module 102 to collect the point cloud data of the material pile through the network transmission module 301 is shown in fig. 3.

Firstly, the intelligent processing module 302 sends out a control instruction according to a preset movement speed, and the control instruction is sent to the cableway pulley module 105 through the network transmission module 301 and the first wireless transmission module 104. The cableway pulley module 105 receives the control command, and the electric pulley drives the laser radar module 106 to move on the cableway along the positive direction of the x axis (in fig. 1).

The intelligent processing module 302 sends an acquisition command to the laser radar module 106 through the network transmission module 301 and the first wireless transmission module 104, the laser radar module 106 starts scanning, and scanning point cloud data passing through the material position at present is transmitted back to the intelligent processing module 302 through the first wireless transmission module 104 and the network transmission module 301 in real time.

When the electric block moves to the end point along the cableway direction, the intelligent processing module 302 simultaneously sends a movement instruction to the electric slide rail module 102 through the network transmission module 301, the second wireless transmission module 103 and the third wireless transmission module 108, and after receiving the movement instruction, the motors on the two sides of the electric slide rail module 102 simultaneously drive the two blocks 101 to advance for a specified distance along the positive direction of the y axis (in fig. 1), and then the operation is stopped. At this time, the intelligent processing module 302 sends an instruction to the cableway pulley module 105 through the network transmission module 301 and the first wireless transmission module 104 again, so that the electric pulley moves along the x-axis negative direction. Averagely taking k calibration position points along the slide rail in the y-axis direction, stopping the electric slide rail module 102 when reaching one calibration position point, averagely taking n position points along the cableway in the x-axis direction, and acquiring point cloud data m times by the laser radar module 106 when the cableway pulley module 105 reaches one position point on the cableway.

In one embodiment of the invention, the warehouse has a length of 100 meters in the y-axis direction, a width of 40 meters in the x-axis direction, and a height of 10 meters. In order to ensure the volume calculation accuracy of the warehouse materials, the laser radar samples every 5 centimeters in the x-axis direction running along the cableway, so that n is 800. The scanning coverage radius of the laser radar is 10 meters, and every 5 meters of the laser radar on the y-axis slide rail is taken as a calibration position point, so that k is 20. m is the number of point clouds collected by each frame of the laser radar, and the number of data collected by the laser radar is 2000 per frame.

After the above steps are completed, the intelligent processing module 302 receives all the material pile point cloud data from the laser radar module 106 through the first wireless transmission module 104 and the network transmission module 301, and obtains k × m × n spatial point cloud data, so that the collection is completed.

In one embodiment of the present invention, the amount of point cloud data obtained by the intelligent processing module 302 is 2000 × 20 × 800 spatial point cloud data.

After the acquisition is finished, the intelligent processing module 302 sends a reset instruction to the electric slide rail module 102 and the cableway pulley module 105 through the network transmission module 301 and the wireless data transmission module, so that the electric slide rail module and the cableway pulley module are reset to the initial position. After the cableway pulley module 105 moves to the initial position, the wireless charging transmitting device automatically carries out wireless charging on the power supply battery on the cableway pulley.

The process of processing the cloud data of the material pile point by the intelligent processing module 302 is shown in fig. 4.

The intelligent processing module 302 performs invalid point elimination, point cloud matching and point cloud data splicing on the acquired k × m × n space point cloud data to form complete and effective warehouse material surface space point cloud. The intelligent processing module 302 uses the ground of the warehouse as the bottom surface of the material, in the x-axis direction, the point clouds collected at each position are connected by using the B-spline curve of the control point, the two ends of the y-axis are used as the boundary, the fixed integral calculation is carried out on the B-spline curve, the area enveloped by the B-spline curve is obtained, and the sum of the product of the area enveloped by the B-spline curve and the distance point in the x-axis direction is the material volume.

And comparing the calculated volume of the material with the volume of the material stored in the previous database, and generating alarm data when the volume of the material changes. The intelligent processing module 302 sends the volume change difference and the alarm related information to the cloud user through the network transmission module 301.

The point cloud data processing method of one embodiment of the invention is as follows:

the method comprises the steps of collecting point cloud data every 5 meters, taking the data collected every time at intervals as a section of a material pile in the vertical direction, taking the ground of the warehouse as the bottom surface of a material pile body, and calculating the volume of the material pile according to an area integral principle;

the point cloud data noise elimination module is used for eliminating and simplifying invalid points of point cloud data on a cross section in the vertical direction according to the position and the angle of a known radar erected in a warehouse, in one embodiment of the invention, the scanning detection range of the radar is 270 degrees, and the radar is arranged at a position 1 meter away from the roof and is higher than the material stacking height, so that only the collected point cloud data within less than 180 degrees need to be reserved;

combining the characteristics of actual point cloud collection, calculating an envelope curve of a section of the material in the vertical direction by a B-spline curve fitting calculation module aiming at point cloud data at the same position of an x axis by adopting a B-spline curve fitting method (the prior art), calculating the surrounding area of the curve at the section in the vertical direction according to the envelope curve, and further obtaining the volume of the warehouse material pile according to the product of the sum of the area of the sections calculated at each position and the distance between each section;

for the y-axis direction, the coverage radius of the laser radar is 10 meters, and the sampling interval is 5 meters, so that the obtained point cloud data has an overlapping area, and for the point cloud data in the overlapping area, the point cloud data noise elimination module eliminates the noise of the point cloud data by adopting a way of combining a point cloud matching algorithm (the prior art) with the physical position and angle matching of the collected point cloud;

the method comprises the steps of extracting collected point cloud data covering 6 meters at the same position of a y axis, iteratively accumulating the point cloud data of the y axis and the point cloud data of the y axis, obtaining the position with the minimum error sum, namely the position of the coincidence position of the same position scanning twice, calculating the average value of the position of the coincidence position after noise points are removed, ensuring the accuracy and reliability of the obtained point cloud data, and improving the material volume calculation precision.

In conclusion, the invention provides an indoor material supervision device, which has the characteristics of full-automatic material stack body measurement, no dead angle in measurement, high precision and timely alarm, and greatly reduces the uncertainty and monitoring cost caused by manpower.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be taken as limiting the invention. Variations, modifications, substitutions and alterations of the above-described embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.