阅读说明：本技术 一种用于室内多目标定位的超声波定位系统及方法 (ultrasonic positioning system and method for indoor multi-target positioning ) 是由 黄大荣 李芸倩 佘兴彬 张续 江晓松 李洪勇 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种用于室内多目标定位的超声波定位系统,其中,定位目标包括第一超声波收发模块及第一时钟模块；超声波定位装置包括第二超声波收发模块及第二时钟模块；时钟同步装置包括第三超声波收发模块及第三时钟模块；定位区域内任意位置的第一超声波收发模块至少能与两个第二超声波收发模块相互传递超声波信号,第三超声波收发模块能够与所有第一超声波收发模块及所有第二超声波收发模块相互传递超声波信号。本发明还公开了基于上述系统的用于室内多目标定位的超声波定位方法。与现有技术相比,本发明能够实现设备之间的时钟同步,进而获得较为精确的超声波传播时间,提高超声波定位系统的定位精度。(The invention discloses ultrasonic positioning systems for indoor multi-target positioning, wherein a positioning target comprises a ultrasonic transceiver module and a clock module, an ultrasonic positioning device comprises a second ultrasonic transceiver module and a second clock module, a clock synchronization device comprises a third ultrasonic transceiver module and a third clock module, the ultrasonic transceiver module at any position in a positioning area can at least mutually transmit ultrasonic signals with the two second ultrasonic transceiver modules, and the third ultrasonic transceiver module can mutually transmit ultrasonic signals with all the ultrasonic transceiver modules and all the second ultrasonic transceiver modules.)

The ultrasonic positioning system for indoor multi-target positioning is characterized by comprising a clock synchronization device, a positioning target, an ultrasonic positioning device and a processor in communication connection with the ultrasonic positioning device, wherein the positioning target comprises a th ultrasonic receiving and transmitting module and a th clock module, the ultrasonic positioning device comprises a second ultrasonic receiving and transmitting module and a second clock module, the clock synchronization device comprises a third ultrasonic receiving and transmitting module and a third clock module, the th ultrasonic receiving and transmitting module at any position in a positioning area can at least mutually transmit ultrasonic signals with the two second ultrasonic receiving and transmitting modules, and the third ultrasonic receiving and transmitting module can mutually transmit ultrasonic signals with all th ultrasonic receiving and transmitting modules and all second ultrasonic receiving and transmitting modules.

ultrasonic positioning method for indoor multi-target positioning, characterized in that the ultrasonic positioning system for indoor multi-target positioning according to claim 1 is used to realize indoor multi-target positioning, and the ultrasonic positioning method for indoor multi-target positioning comprises the following steps:

s1, performing clock synchronization of the positioning target, the ultrasonic positioning device and the clock synchronization device;

s2, the positioning target sends ultrasonic positioning signals containing sending time to at least two ultrasonic positioning devices;

s3, the ultrasonic positioning device sends the time for receiving the ultrasonic positioning signal and the sending time to the processor;

and S4, the processor determines the position of the positioning target based on the time of receiving the ultrasonic positioning signal and the sending time.

3. An ultrasonic positioning method for indoor multi-object positioning as defined in claim 2, wherein step S1 includes:

the third ultrasonic transceiver module sends ultrasonic signals to each th ultrasonic transceiver module and each second ultrasonic transceiver module, and records corresponding sending time;

each ultrasonic transceiver module and each second ultrasonic transceiver module feed back ultrasonic signals to the third ultrasonic transceiver module after receiving the ultrasonic signals sent by the third ultrasonic transceiver module;

the third ultrasonic transceiver module receives the ultrasonic signals fed back by each th ultrasonic transceiver module and each second ultrasonic transceiver module and records corresponding receiving time;

calculating a time delay with one-way propagation between each th ultrasonic transceiver module and each second ultrasonic transceiver module based on the transmission time and the reception time;

the third ultrasonic transceiver module sends ultrasonic time synchronization signals to each th ultrasonic transceiver module and each second ultrasonic transceiver module, and the ultrasonic time synchronization signals comprise ultrasonic time synchronization signal sending time and corresponding one-way propagation time delay;

each th ultrasonic transceiver module and each second ultrasonic transceiver module achieve clock synchronization with the third ultrasonic transceiver module based on the transmission time of the synchronization signal and the corresponding one-way propagation time delay.

4. An ultrasonic positioning method for indoor multi-object positioning as defined in claim 1, wherein step S4 includes:

the processor calculates the propagation time of the positioning target and the ultrasonic positioning device and calculates the propagation distance based on the time of receiving the ultrasonic positioning signal and the sending time; and fitting the propagation distance by using a polynomial fitting function, inquiring a corresponding table between the measured distance and the real distance according to the data obtained by fitting, and analyzing and processing the data obtained by inquiry by using a Kalman filter to obtain the position of the intelligent trolley.

5. An ultrasonic positioning method for indoor multi-object positioning according to claim 4, further comprising:

dividing the positioning area into a plurality of grids, measuring the actual position and the measured position of each grid, and establishing a corresponding table between the measured distance and the actual distance.

6. An ultrasonic positioning method for multi-object positioning indoors as claimed in claim 4, wherein the positioning target transmits ultrasonic positioning signals including transmission times to at least two ultrasonic positioning devices a plurality of times within a preset time, the processor performs data smoothing on the times of receiving the ultrasonic positioning signals a plurality of times and the transmission times by using a sliding mean filter, and then performs arithmetic averaging to obtain the propagation time, and the preset time is less than or equal to 5 ms.

Technical Field

The invention relates to the field of positioning, in particular to ultrasonic positioning systems and methods for indoor multi-target positioning.

Background

Most of the existing positioning technologies achieve positioning of targets based on GPS signals, and although the positioning requirements of most users can be met, in a specific scene, satellite positioning is difficult to meet the requirements of target positioning, such as target positioning in an indoor scene. In order to meet the requirement of target positioning in indoor scenes, researchers invent various indoor positioning technologies so as to meet the positioning requirement in special scenes.

Common indoor positioning technologies include Wi-Fi-based positioning technology, bluetooth-based positioning technology, infrared-based positioning technology, RFID-based positioning technology, ultrasonic-based positioning technology, and the like. The Wi-Fi-based positioning technology and the Bluetooth-based positioning technology have similar working principles, and the distance from a target to be positioned to a fixed node is estimated by measuring the RSSI value of the target to be positioned, so that the position of the current target is calculated. Because Wi-Fi signal and bluetooth signal all receive the interference of other signals easily, lead to positioning accuracy lower, and the installation cost is higher, are not suitable for the location of targets such as indoor intelligent vehicle. Due to the linear propagation characteristic of infrared rays, signals are difficult to pass through obstacles, and the infrared-based positioning technology cannot be used for target positioning requirements in complex scenes. The RFID-based positioning technology adopts a radio frequency mode to perform non-contact bidirectional communication data exchange, can provide positioning service with centimeter-level precision, but because the RFID is not convenient to integrate into a target to be positioned, and secondly, more RFID beacons are required to be arranged for realizing high-precision positioning, and the installation is troublesome.

The positioning technology based on ultrasonic waves has high overall positioning accuracy and simple system structure, and is suitable for positioning indoor targets, but the existing ultrasonic positioning system is usually based on a reflection type distance measurement method, namely an ultrasonic signal transceiver module is integrated into without synchronizing clock signals at a transceiver end, but the module is less used for constructing the positioning system, because the modules can generate interference when being simultaneously applied, and the position change of each vehicle can not be observed in real time.

In summary, how to implement clock synchronization in indoor multi-target positioning so as to implement accurate positioning of indoor multiple targets is a problem that needs to be solved urgently by those skilled in the art.

Disclosure of Invention

Aiming at the defects in the prior art, the technical problems to be solved by the invention are as follows: how to predict the driving state of the vehicle on the road in advance provides a judgment basis for a driver, and safety accidents are avoided.

In order to solve the technical problems, the invention adopts the following technical scheme:

ultrasonic positioning system for indoor multi-target positioning comprises a clock synchronization device, a positioning target, an ultrasonic positioning device and a processor in communication connection with the ultrasonic positioning device, wherein the positioning target comprises a ultrasonic transceiver module and a clock module, the ultrasonic positioning device comprises a second ultrasonic transceiver module and a second clock module, the clock synchronization device comprises a third ultrasonic transceiver module and a third clock module, the ultrasonic transceiver module at any position in a positioning area can at least mutually transmit ultrasonic signals with two second ultrasonic transceiver modules, and the third ultrasonic transceiver module can mutually transmit ultrasonic signals with all ultrasonic transceiver modules and all second ultrasonic transceiver modules.

Preferably, the ultrasonic positioning system for indoor multi-target positioning is adopted to realize indoor multi-target positioning, and the ultrasonic positioning method for indoor multi-target positioning comprises the following steps:

s1, performing clock synchronization of the positioning target, the ultrasonic positioning device and the clock synchronization device;

s2, the positioning target sends ultrasonic positioning signals containing sending time to at least two ultrasonic positioning devices;

s3, the ultrasonic positioning device sends the time for receiving the ultrasonic positioning signal and the sending time to the processor;

and S4, the processor determines the position of the positioning target based on the time of receiving the ultrasonic positioning signal and the sending time.

Preferably, step S1 includes:

the third ultrasonic transceiver module sends ultrasonic signals to each th ultrasonic transceiver module and each second ultrasonic transceiver module, and records corresponding sending time;

each ultrasonic transceiver module and each second ultrasonic transceiver module feed back ultrasonic signals to the third ultrasonic transceiver module after receiving the ultrasonic signals sent by the third ultrasonic transceiver module;

the third ultrasonic transceiver module receives the ultrasonic signals fed back by each th ultrasonic transceiver module and each second ultrasonic transceiver module and records corresponding receiving time;

calculating a time delay with one-way propagation between each th ultrasonic transceiver module and each second ultrasonic transceiver module based on the transmission time and the reception time;

the third ultrasonic transceiver module sends ultrasonic time synchronization signals to each th ultrasonic transceiver module and each second ultrasonic transceiver module, and the ultrasonic time synchronization signals comprise ultrasonic time synchronization signal sending time and corresponding one-way propagation time delay;

each th ultrasonic transceiver module and each second ultrasonic transceiver module achieve clock synchronization with the third ultrasonic transceiver module based on the transmission time of the synchronization signal and the corresponding one-way propagation time delay.

Preferably, step S4 includes:

the processor calculates the propagation time of the positioning target and the ultrasonic positioning device and calculates the propagation distance based on the time of receiving the ultrasonic positioning signal and the sending time; and fitting the propagation distance by using a polynomial fitting function, inquiring a corresponding table between the measured distance and the real distance according to the data obtained by fitting, and analyzing and processing the data obtained by inquiry by using a Kalman filter to obtain the position of the intelligent trolley.

Preferably, the method further comprises the following steps:

dividing the positioning area into a plurality of grids, measuring the actual position and the measured position of each grid, and establishing a corresponding table between the measured distance and the actual distance.

Preferably, within a preset time, the positioning target sends multiple ultrasonic positioning signals including sending time to at least two ultrasonic positioning devices, the processor performs data smoothing on the multiple times of receiving the ultrasonic positioning signals and the sending time by using a sliding average filter, and then performs arithmetic averaging to obtain the propagation time, wherein the preset time is less than or equal to 5 ms.

In summary, the ultrasonic positioning system and method for indoor multi-target positioning disclosed by the invention can solve the following problems:

through a clock synchronization mechanism similar to a PTP protocol, clocks of the ultrasonic signal transmitting and receiving ends are synchronized to obtain more accurate ultrasonic propagation time.

The ultrasonic wave signals are modulated to carry local time information of signal transmitting time, and the local time information is used for calculating the propagation time of the ultrasonic wave.

The acquired ultrasonic propagation time is processed by a digital signal processing method so as to improve the positioning accuracy of the ultrasonic positioning system.

Drawings

FIG. 1 is a flow chart of embodiments of the disclosed ultrasonic positioning method for indoor multi-object positioning;

FIG. 2 is a schematic position diagram of a embodiment ultrasonic locating device of the ultrasonic locating system for indoor multi-object location disclosed in the present invention.

Detailed Description

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 with reference to the accompanying drawings.

The invention discloses an ultrasonic positioning system for indoor multi-target positioning, which comprises a clock synchronization device, a positioning target, an ultrasonic positioning device and a processor in communication connection with the ultrasonic positioning device, wherein the positioning target comprises a ultrasonic transceiver module and a clock module, the ultrasonic positioning device comprises a second ultrasonic transceiver module and a second clock module, the clock synchronization device comprises a third ultrasonic transceiver module and a third clock module, the ultrasonic transceiver module at any position in a positioning area can at least mutually transmit ultrasonic signals with two second ultrasonic transceiver modules, and the third ultrasonic transceiver module can mutually transmit ultrasonic signals with all ultrasonic transceiver modules and all the second ultrasonic transceiver modules.

As shown in fig. 2, in a specific implementation, four ultrasonic positioning devices (a to D in fig. 2) may be used, and are distributed around a positioning area, the positioning area is set to be a square of 1.5m by 1.5m, a driving area of a vehicle is in the square, and in order to ensure full coverage of the area, the positioning devices are distributed in the center of an area boundary: when the ultrasonic locating devices are distributed at the four midpoints of the boundary of the locating area, as shown in the figure. Because the minimum measurement distance is not less than 35cm, the view blind area of each receiving end is within the circumferential range taking 35cm as the radius and taking each receiving end as the center of a circle, but because the maximum measurement distance of two receiving ends on adjacent boundaries is 120cm, the view blind area of each receiving end can be ensured to be within the effective distance measurement range of the other two receiving ends. Thus, distributing the ultrasonic locating devices at the center of the boundary of the locating area maximizes the effective ranging coverage of the ultrasonic locating system. And in order to ensure that all the positioning targets and the ultrasonic positioning device can be synchronized with the clock synchronization device, the clock synchronization device is arranged in the center of the square.

In the invention, the working principle of the ultrasonic positioning system for indoor multi-target positioning is as follows:

s1, performing clock synchronization of the positioning target, the ultrasonic positioning device and the clock synchronization device;

s2, the positioning target sends ultrasonic positioning signals containing sending time to at least two ultrasonic positioning devices;

s3, the ultrasonic positioning device sends the time for receiving the ultrasonic positioning signal and the sending time to the processor;

and S4, the processor determines the position of the positioning target based on the time of receiving the ultrasonic positioning signal and the sending time.

The existing positioning technology such as Wi-Fi-based positioning technology, Bluetooth-based positioning technology and the like is difficult to meet the accurate positioning requirement of targets such as intelligent vehicles and the like in indoor scenes due to high installation cost and easy interference of other signals. The ultrasonic positioning system provided by the invention has lower installation cost, and can obtain higher positioning precision by matching with the method provided by the invention.