Distance measurement method and system
阅读说明：本技术 一种测距方法和系统 (Distance measurement method and system ) 是由 王丹 陆满君 吴雄君 李志民 唐坤 于 2019-12-02 设计创作，主要内容包括：本发明公开了一种测距方法和系统,包含：第一定标杆,置于起始点且其上分别设有第一信标和第二信标,第一定标杆与地平面垂直,第一信标和第二信标位于不同的高度位置；第二定标杆,置于目标点且其上设有信源,第二定标杆保持与地平面垂直；第一信标和第二信标分别与信源无线通信,分别得到第一信标与信源之间以及第二信标与信源之间的信号传输时间差,进而得到第一信标到信源之间的距离以及第二信标到信源之间的距离的测量,最终获得起始点与目标点之间的距离。本发明利用多个信源和信标组合来实现距离测量,实现起始点和目标点之间的距离的测量,而且不受两个位置海拔高度不一致的影响。(The invention discloses a distance measuring method and a system, comprising: the first beacon post is arranged at the starting point and is provided with a first beacon and a second beacon respectively, the first beacon post is vertical to the ground plane, and the first beacon and the second beacon are positioned at different height positions; the second calibration rod is arranged at the target point and provided with an information source, and the second calibration rod is kept perpendicular to the ground plane; the first beacon and the second beacon are in wireless communication with the information source respectively, signal transmission time differences between the first beacon and the information source and between the second beacon and the information source are obtained respectively, further the distance between the first beacon and the information source and the distance between the second beacon and the information source are measured, and finally the distance between the starting point and the target point is obtained. The invention realizes distance measurement by combining a plurality of information sources and beacons, realizes the measurement of the distance between a starting point and a target point, and is not influenced by the inconsistency of the altitudes of the two positions.)
1. A ranging system, comprising:
the first beacon post is arranged at the starting point and is provided with a first beacon and a second beacon respectively, the first beacon post is vertical to the ground plane, and the first beacon and the second beacon are positioned at different height positions;
the second calibration rod is arranged at the target point and provided with an information source, and the second calibration rod is kept perpendicular to the ground plane; the first beacon and the second beacon are in wireless communication with the information source respectively, signal transmission time differences between the first beacon and the information source and between the second beacon and the information source are obtained respectively, further the distance between the first beacon and the information source and the distance between the second beacon and the information source are measured, and finally the distance between the starting point and the target point is obtained.
2. The ranging system of claim 1,
the beacon includes:
the first special ultra-wideband transceiving chip is used for receiving or transmitting ultra-wideband pulse signals;
and the first microprocessor is connected with the first special ultra-wideband transceiver chip through a serial port to complete the conversion between data and ultra-wideband pulse signals.
3. The ranging system according to claim 1 or 2,
the source includes:
the second special ultra-wideband transceiving chip is used for receiving or transmitting ultra-wideband pulse signals;
and the second microprocessor is connected with the second special ultra-wideband transceiver chip through a serial port to complete the conversion between the data and the ultra-wideband pulse signal.
4. The ranging system of claim 3,
the source further comprises:
the display module is connected with the second microprocessor through a serial port and used for displaying distance information;
and the storage module is connected with the second microprocessor through a serial port and is used for storing the data to be retained or providing the stored data to the second microprocessor so as to facilitate the access of the second microprocessor.
5. The ranging system according to claim 2 or 3 or 4,
the beacon and/or the source further comprise;
a battery for providing power to the beacon or the source;
the power supply switching module is used for switching the power supply mode;
the power supply conversion module is used for converting voltage;
when the external power supply mode is adopted, the external power supply provides voltage input of the whole beacon and/or the signal source, the power supply conversion module performs voltage conversion on the external power supply to provide special voltage for the beacon and/or the signal source, and meanwhile, the power supply conversion module connects the external power supply with a corresponding battery to finish charging the battery;
when the system normal power supply mode is adopted and the external power supply is removed, the corresponding battery in the beacon and/or the information source supplies power to the system, the power supply conversion module converts the output voltage of the battery to the voltage used by the beacon and/or the information source, and meanwhile, an interface with the external power supply is cut off.
6. A ranging method based on the ranging system as claimed in any of claims 1 to 5, characterized in that the method comprises the following steps:
step T1: respectively placing a first calibration rod and a second calibration rod at a starting point and a target point, and keeping the first calibration rod and the second calibration rod perpendicular to a ground plane;
step T2: respectively starting a first beacon on a first calibration rod, a second beacon on the first calibration rod and an information source on a second calibration rod, wherein the first beacon and the second beacon are respectively in wireless communication with the information source to respectively obtain signal transmission time differences between the first beacon and the information source and between the second beacon and the information source, so as to further obtain the distance between the first beacon and the information source and the distance between the second beacon and the information source;
step T3: the source calculates the horizontal distance between the starting point and the target point.
The step T2 further includes the following steps:
the first beacon and the second beacon are in wireless communication with an information source respectively, and the information source is in a monitoring state and waits for first handshake signals of the beacons respectively;
each beacon is awakened from an idle state periodically and sends corresponding first handshake signals to the information source respectively;
the information source receives the first handshake signals sent by the beacons, and replies corresponding second data frames to the beacons to prompt the beacons to carry out subsequent communication ranging processes;
each beacon records a corresponding current first time T1Writing data into corresponding bytes of a corresponding pre-sent third data frame Poll, and immediately sending the third data frame Poll; after receiving each third data frame Poll, the information source records the current second time T respectively2And the effective data T carried by the third data frame Poll1The information is stored in a microprocessor of the information source;
the information sources respectively record the current third time T3Then respectively sending a fourth data frame Reverse to each beacon; after each beacon receives the corresponding fourth data frame replay respectively, the corresponding fourth data frame replay is recorded respectivelyFourth previous time T4；
Each beacon respectively records the current fifth time T5And respectively converting the data T at the fourth time and the fifth time4、T5Writing the data into corresponding bytes of a fifth data frame Final which is to be sent, and immediately sending the fifth data frame Final to the information source respectively; after the information source receives the corresponding fifth data frame Final, respectively recording the current sixth time T6；
The information source records the first time T according to the above1To a sixth time T6Substituting the formula (1) to calculate to respectively obtain the transmission time difference T between the first beacon and the information source and between the second beacon and the information sourceTWRSubstituting the first beacon into a formula (2), respectively calculating the distance between the first beacon and the information source and the distance between the second beacon and the information source, and displaying the distances on a display module of the information source; the equations (1) and (2) are:
D＝c×TTWR(2)
wherein, T1Is the time, T, at which the respective beacon sends the third data frame Poll2Is the time, T, at which the source receives the third data frame Poll3Is the time, T, at which the source sends the fourth data frame response4Is the time, T, at which the respective beacon receives the fourth data frame response5Is the time, T, at which the respective beacon transmits the fifth data frame Final6The moment when the source receives the fifth data frame Final; t isround1＝T4-T1，Tround2＝T6-T3，Treply1＝T3-T2，Treply2＝T5-T4(ii) a D represents the distance between the beacon and the source; c represents the speed of propagation of the radio in the air.
7. The ranging method of claim 6,
the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-1) as follows:
wherein D isABIs the distance between the first beacon and the second beacon, a known quantity; dACIs the distance between the first beacon and the source; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point on the line segment AB, which is equal to the height of the information source; dHBIs the distance between the second beacon and point H; dCHIs the distance between the source and the point H, i.e. the horizontal distance between the starting point and the target point.
8. The ranging method of claim 6,
the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-2) as follows:
wherein D isABIs the distance between the first beacon and the second beacon, a known quantity; dACIs the distance between the first beacon and the source; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point which is equal to the height of the information source on the extension line of the line segment AB in the downward direction; dHBIs the distance between the second beacon and point H; dCHIs the distance between the source and the point H, i.e. the horizontal distance between the starting point and the target point.
9. The ranging method of claim 6,
the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-3) as follows:
wherein D isABIs the distance between the first beacon a and the second beacon B, a known amount; dACIs the distance between the first beacon and the source C; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point with the height equal to that of the information source C on the upward direction extension line of the line segment AB; dHBIs the distance between the second beacon B and the point H, DCHIs the distance between the source C and the point H, i.e. the horizontal distance between the starting point and the target point.
Technical Field
The invention relates to the technical field of radio ranging, in particular to a method and a system for realizing distance measurement by utilizing a plurality of information sources and beacon combinations.
Background
In working scenes such as map mapping, engineering construction and the like, the problem of measuring the horizontal distance between two coordinate points at high precision is often involved, in a field environment, detection equipment based on laser, infrared and the like mostly depends on linear propagation of light due to the shielding of trees and plants, and is difficult to use in the occasions due to the fact that the detection equipment is based on the measurement mechanism of the detection equipment. Distance measurement under some indoor environment, because the sheltering from of indoor goods shelves, article, the application range of distancer based on laser, infrared is also very limited. The ranging method based on pulse radio communication can effectively solve the problem, and is particularly used in occasions with low precision requirements. The method for measuring the distance based on the pulse radio communication has the advantages of high transmission rate, strong anti-interference capability, good environmental adaptability and the like, and is more and more emphasized in the occasions of distance measurement and indoor positioning.
The ultra-wideband communication is a carrier-free communication technology, uses nanosecond-level non-sine wave narrow pulse to transmit data, and can realize the data transmission rate of hundreds of Mbits/s-Gbits/s in the range of about 10 meters. The time domain adopts the extremely narrow pulse, on the frequency domain, the occupied bandwidth is wider, the wireless power density is low, other wireless equipment cannot be interfered, and the self anti-interference performance is enhanced. The ultra-wideband communication does not need carrier waves, only needs to transmit instantaneous pulse signals, consumes little electric energy, is very suitable for being adopted in portable measuring instruments with higher power consumption requirements, and has the measuring precision of up to 10 cm.
Ultra-wideband communication mainly achieves measurement of the distance between a signal source and a beacon through wireless communication between the beacon and the signal source. For example, when bilateral two-way symmetric ranging is adopted, a communication mode with a certain flow is formed between a beacon and an information source, and in the communication flow, the time of a time mark reaching different nodes in the communication flow is recorded, which is equivalent to calculating the transmission time of a pulse between the beacon and the information source, so that the distance between the beacon and the information source is calculated. Therefore, it is necessary to develop a method and system for distance measurement using multiple source and beacon combinations.
Disclosure of Invention
The invention aims to provide a distance measurement method and a distance measurement system, which realize distance measurement by utilizing a plurality of information sources and beacon combinations, realize the measurement of the distance between a starting point and a target point and are not influenced by the inconsistency of the altitudes of two positions.
In order to achieve the purpose, the invention is realized by the following technical scheme:
a ranging system, comprising:
the first beacon post is arranged at the starting point and is provided with a first beacon and a second beacon respectively, the first beacon post is vertical to the ground plane, and the first beacon and the second beacon are positioned at different height positions;
the second calibration rod is arranged at the target point and provided with an information source, and the second calibration rod is kept perpendicular to the ground plane; the first beacon and the second beacon are in wireless communication with the information source respectively, signal transmission time differences between the first beacon and the information source and between the second beacon and the information source are obtained respectively, further the distance between the first beacon and the information source and the distance between the second beacon and the information source are measured, and finally the distance between the starting point and the target point is obtained.
Preferably, the beacon comprises:
the first special ultra-wideband transceiving chip is used for receiving or transmitting ultra-wideband pulse signals;
and the first microprocessor is connected with the first special ultra-wideband transceiver chip through a serial port to complete the conversion between data and ultra-wideband pulse signals.
Preferably, the source comprises:
the second special ultra-wideband transceiving chip is used for receiving or transmitting ultra-wideband pulse signals;
and the second microprocessor is connected with the second special ultra-wideband transceiver chip through a serial port to complete the conversion between the data and the ultra-wideband pulse signal.
Preferably, the source further comprises:
the display module is connected with the second microprocessor through a serial port and used for displaying distance information;
and the storage module is connected with the second microprocessor through a serial port and is used for storing the data to be retained or providing the stored data to the second microprocessor so as to facilitate the access of the second microprocessor.
Preferably, said beacon and/or said source further comprises;
a battery for providing power to the beacon or the source;
the power supply switching module is used for switching the power supply mode;
the power supply conversion module is used for converting voltage;
when the external power supply mode is adopted, the external power supply provides voltage input of the whole beacon and/or the signal source, the power supply conversion module performs voltage conversion on the external power supply to provide special voltage for the beacon and/or the signal source, and meanwhile, the power supply conversion module connects the external power supply with a corresponding battery to finish charging the battery;
when the system normal power supply mode is adopted and the external power supply is removed, the corresponding battery in the beacon and/or the information source supplies power to the system, the power supply conversion module converts the output voltage of the battery to the voltage used by the beacon and/or the information source, and meanwhile, an interface with the external power supply is cut off.
The invention also provides a distance measuring method based on the distance measuring system, which comprises the following steps:
step T1: respectively placing a first calibration rod and a second calibration rod at a starting point and a target point, and keeping the first calibration rod and the second calibration rod perpendicular to a ground plane;
step T2: respectively starting a first beacon on a first calibration rod, a second beacon on the first calibration rod and an information source on a second calibration rod, wherein the first beacon and the second beacon are respectively in wireless communication with the information source to respectively obtain signal transmission time differences between the first beacon and the information source and between the second beacon and the information source, so as to further obtain the distance between the first beacon and the information source and the distance between the second beacon and the information source;
step T3: the source calculates the horizontal distance between the starting point and the target point.
The step T2 further includes the following steps:
the first beacon and the second beacon are in wireless communication with an information source respectively, and the information source is in a monitoring state and waits for first handshake signals of the beacons respectively;
each beacon is awakened from an idle state periodically and sends corresponding first handshake signals to the information source respectively;
the information source receives the first handshake signals sent by the beacons, and replies corresponding second data frames to the beacons to prompt the beacons to carry out subsequent communication ranging processes;
each beacon records a corresponding current first time T1Writing data into corresponding bytes of a corresponding pre-sent third data frame Poll, and immediately sending the third data frame Poll; after receiving each third data frame Poll, the information source records the current second time T respectively2And the effective data T carried by the third data frame Poll1The information is stored in a microprocessor of the information source;
the information sources respectively record the current third time T3Then respectively sending a fourth data frame Reverse to each beacon; after each beacon receives the corresponding fourth data frame replay, the beacon records the current fourth time T4；
Each beacon respectively records the current fifth time T5And respectively converting the data T at the fourth time and the fifth time4、T5Writing the data into corresponding bytes of a fifth data frame Final which is to be sent, and immediately sending the fifth data frame Final to the information source respectively; after the information source receives the corresponding fifth data frame Final, respectively recording the current sixth time T6；
The information source records the first time T according to the above1To a sixth time T6Substituting the formula (1) to calculate to respectively obtain the transmission time difference T between the first beacon and the information source and between the second beacon and the information sourceTWRAnd substituting the obtained product into formula (2) to respectively calculateCalculating the distance between the first beacon and the information source and the distance between the second beacon and the information source, and displaying the distances on a display module of the information source; the equations (1) and (2) are:
D＝c×TTWR(2)
wherein, T1Is the time, T, at which the respective beacon sends the third data frame Poll2Is the time, T, at which the source receives the third data frame Poll3Is the time, T, at which the source sends the fourth data frame response4Is the time, T, at which the respective beacon receives the fourth data frame response5Is the time, T, at which the respective beacon transmits the fifth data frame Final6The moment when the source receives the fifth data frame Final; t isround1＝T4-T1，Tround2＝T6-T3，Treply1＝T3-T2，Treply2＝T5-T4(ii) a D represents the distance between the beacon and the source; c represents the speed of propagation of the radio in the air.
Preferably, the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-1) as follows:
wherein D isABIs the distance between the first beacon and the second beacon, a known quantity; dACIs the distance between the first beacon and the source; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point on the line segment AB, which is equal to the height of the information source; dHBIs the distance between the second beacon and point H; dCHIs the distance between the source and the point H, i.e. the horizontal distance between the starting point and the target point.
Preferably, the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-2) as follows:
wherein D isABIs the distance between the first beacon and the second beacon, a known quantity; dACIs the distance between the first beacon and the source; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point which is equal to the height of the information source on the extension line of the line segment AB in the downward direction; dHBIs the distance between the second beacon and point H; dCHThe distance between the source and the point H, namely the horizontal distance between the starting point and the target point;
preferably, the step T3 further includes:
the source calculates the horizontal distance between the starting point and the target point according to equation set (3-3) as follows:
wherein D isABIs the distance between the first beacon a and the second beacon B, a known amount; dACIs the distance between the first beacon and the source C; dBCIs the distance between the second beacon and the source; dAHThe distance between the first beacon and a point H is the point with the height equal to that of the information source C on the upward direction extension line of the line segment AB; dHBIs the distance between the second beacon B and the point H, DCHIs the distance between the source C and the point H, i.e. the horizontal distance between the starting point and the target point.
Compared with the prior art, the invention has the beneficial effects that: the distance measurement is realized by combining a plurality of information sources and beacons, the distance between a starting point and a target point is measured, and the influence of the inconsistency of the altitudes of the two positions is avoided; the ultra-wideband communication is adopted between the information source and the beacon, the self anti-interference performance is enhanced, the consumed electric energy is small, the ultra-wideband communication method is suitable for a portable measuring instrument with higher power consumption requirement, and the measuring precision is higher.
Drawings
FIGS. 1-3 are schematic diagrams of the present invention for distance measurement using multiple sources and beacons;
fig. 4 is a flow chart of communication between a beacon and a source of the present invention;
fig. 5 is a schematic hardware component diagram of beacon a or beacon B according to the present invention;
fig. 6 is a diagram showing the hardware composition of the source C of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1-6 in combination, the present invention provides a method and system for distance measurement using multiple sources and beacon combinations, the ranging system comprising a
As shown in fig. 5, the beacon a (or beacon B) includes a first microprocessor, a first dedicated ultra-wideband transceiver chip (also called UWB ranging module), a first battery (e.g. a first lithium battery), and a first power conversion module. The first microprocessor is connected with the first special ultra-wideband transceiver chip through a serial port to complete conversion between data and ultra-wideband pulse signals. The first lithium battery is connected with the first power supply switching module, and the first power supply switching module is connected with the first power supply conversion module. The first lithium battery provides power for the entire beacon transceiver. The first power supply switching module is used for switching power supply and determining an external power supply mode or a normal working mode (power supply of the first lithium battery). The first power conversion module is used for voltage conversion. When an external power supply mode is adopted, external power supply provides voltage input of the whole circuit, the first power supply conversion module converts the voltage of the external power supply on one hand and provides special voltage for a chip on a circuit board, and on the other hand, the external power supply is connected with the first lithium battery to finish charging of the first lithium battery; when the external power supply is removed, namely the system is in a normal working mode, the first lithium battery in the beacon transceiver supplies power to the whole circuit, the first power supply conversion module converts the output voltage of the first lithium battery to the voltage used by the circuit chip, and meanwhile, an interface for external power supply is cut off.
As shown in fig. 6, the information source C includes a second microprocessor, a second dedicated ultra-wideband transceiver chip (also called UWB ranging module), a display module, a storage module, a second battery (for example, a second lithium battery), and a second power conversion module. The second microprocessor is connected with the second special ultra-wideband transceiver chip through a serial port to complete conversion between data and ultra-wideband pulse signals. The storage module is connected with the second microprocessor through a serial port, and stores data to be retained or provides the stored data to the second microprocessor so as to be accessed. The second lithium battery is connected with the second power supply switching module, and the second power supply switching module is connected with the second power supply conversion module. The second lithium battery provides power for the whole information source transceiver. The second power supply switching module is used for switching power supply and determining an external power supply mode or a normal working mode (power supply of a second lithium battery). The second power conversion module is used for voltage conversion. When the external power supply mode is adopted, the external power supply provides voltage input of the whole circuit, the second power supply conversion module converts the voltage of the external power supply on one hand to provide special voltage for a chip on the circuit board, and on the other hand, the external power supply is connected with a second lithium battery to finish charging of the second lithium battery; when the external power supply is removed, namely the system is in a normal working mode, the second lithium battery in the information source transceiver supplies power to the whole circuit, the second power supply conversion module converts the output voltage of the second lithium battery to the voltage used by the circuit chip, and meanwhile, an interface with the external power supply is cut off. And a display module in the information source is connected with the second microprocessor through an SPI bus, and the distance information required to be displayed is displayed.
In a wireless communication system, a common ranging method is based on time of arrival (TOA) estimation, i.e. calculating the time difference T between the transmission and reception of a pulse, and knowing that the propagation speed of a radio in the air is c 3 × 108m/s, then the distance D can be calculated using equation (1):
D＝c×T (1)
due to the influence of the Ranging error caused by clock drift, frequency drift, received signal level and antenna delay, the Ranging mechanism used herein is a method of bilateral Two-dimensional Two-Way Ranging (SDS-TWR), and the communication flow chart is shown in fig. 4, and the specific flow is: assuming that the distance information between the beacon and the source needs to be tested, the beacon is at T1A data frame (Poll) is sent out at time T2The data frame arrives at the information source at the moment, and the information source processes the data frame and processes the data frame at T3A responsive data frame (response) is sent at time T4At the moment, the response frame arrives at the beacon, after processing by the beacon, at T5An end frame (Final) is again sent at time T6The arrival at the information source is a complete ranging process, and the transmission time difference T between the beacon and the information source can be obtained by the derivation of the formula (2)TWR：
Wherein, T1Is the time of sending Poll data frame by beacon, T2Is the time, T, at which the source receives the Poll data frame3Is the time, T, at which the source sends a reply data frame4Is the time, T, at which the beacon receives the reply data frame5Is the time at which the beacon sends the Final data frame, T6Is the time at which the source receives the Final data frame, Tround1＝T4-T1，Tround2＝T6-T3，Treply1＝T3-T2，Treply2＝T5-T4。
Will transmit time difference TTWRSubstituting into equation (1), the distance between the beacon and the source can be calculated.
In the invention, the beacon A and the beacon B of the scaling
As shown in fig. 1, making a perpendicular from point C to segment AB and intersecting at point H, the following equations can be listed according to the pythagorean theorem:
wherein D isABIs the distance between point a and point B, a known quantity; dAHThe distance between the point A and the point H is the point on the line segment AB with the same height as the information source C; dACIs the distance between point a and point C; dHBIs the distance between point B and point H, DCHIs the distance between point C and point H; further derivation from the formula can further yield:
and deducing the required horizontal distance DCHAnd A, B, C, respectively.
In the present invention, since the relative positions of the
corresponding to the situation in fig. 3, equation (6) may be listed:
in practical application, the calculation is carried out according to the formulas (4-6) respectively, and then D is calculatedAHAnd DHBJudging, determining whether the two are positive values or not, discarding the rest, and finally substituting into equation to calculate DCH。
The invention provides a distance measuring method, which comprises the following specific implementation steps in the test process:
step S1: a tester holds the calibration rod by hand, places the
step S2, power switches of the beacon A and the information source C are turned on, the beacon A is in wireless communication with the information source C, the information source C is in a monitoring state, and a handshaking signal of the beacon A is waited;
step S3: beacon a periodically wakes up from an idle state and sends a handshake data frame (Blink) to the source C;
step S4: the information source C receives the handshake signal sent by the beacon A and replies a data frame (RangingInit) to the beacon A to prompt that the beacon A can carry out subsequent communication ranging processes;
step S5: beacon A records the current time TA1Writing data into corresponding bytes of a data frame Poll to be sent, and immediately sending the data frame Poll; letterAfter the source C receives the data frame Poll, the current time T is recordedA2And the effective data T carried by the Poll data frameA1Stored in the microprocessor of the source C;
step S6: the information source C records the current time TA3Then, sending data frame Reverse; after receiving the data frame replay, the beacon A records the current time TA4；
Step S7: beacon A records the current time TA5And data T is combinedA4、TA5Writing the data frame Final into a corresponding byte of the data frame Final to be sent, and immediately sending the data frame Final; after the information source C receives the Final of the data frame, the current time T is recordedA6；
Step S8: source C according to recorded TA1-TA6Substituting the formula (2) for calculation to obtain the distance between the test points AC, and displaying the distance on a display module of the information source C end;
step S9: turning on a power switch of the beacon B, repeating the steps S3-S8, and in the same way, testing the distance between the BC and displaying the distance on a display module of the information source C;
it should be noted that, step S9 described in this embodiment is not limited to this, and here, the distance between the ACs is measured first, and then the distance between the BC is measured, but the present invention may also describe the distance between the BC is measured first, and then the distance between the ACs is measured, and the specific sequence of steps is not limited to the above; in the invention, the power switches of the beacon A and the information source C can be started firstly, then the power switch of the beacon B can be started, the power switches of the beacon B and the information source C can be started firstly, then the power switch of the beacon A can be started, and the power switches of the beacon A and the beacon B information source C can be started simultaneously, so long as the measurement of the distance between the ACs and the distance between the BC can be realized.
Step S10: the information source C performs three sets of calculations according to the formulas (4-6), and then performs the calculation on the information source DAHAnd DHBJudging that the two are positive values, and discarding the rest to calculate DCHAnd displayed on the display module.
In conclusion, the invention can realize the measurement of the distance between the starting point and the target point and is not influenced by the inconsistent altitude of the two positions.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. Various modifications and alterations to this invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be determined from the following claims.
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