CN217543371U - Indoor positioning system based on ultrasonic ranging - Google Patents

Abstract

An indoor positioning system based on ultrasonic ranging, comprising: the system comprises a fixed base station and a mobile terminal positioning node, wherein the fixed base station is fixedly arranged at the indoor top, and the mobile terminal positioning node is arranged indoors; the fixed base station comprises a first main control MCU which is respectively and electrically connected with a first wireless communication module, a first ultrasonic transmitting and receiving module and a first power supply module and processes data information of each module; the mobile end positioning node comprises a second main control MCU, the second main control MCU is respectively and electrically connected with a second wireless communication module, a second ultrasonic transmitting and receiving module, a steering engine module, an electronic compass module and a second power module, and data information of all the modules is processed to enable the mobile end node to complete positioning; through the technical scheme, the indoor environment is accurately positioned, the system has the advantages of low cost and few blind areas, and is simple in structure and flexible in positioning.

Description

An indoor positioning system based on ultrasonic ranging

technical field

The utility model relates to the technical field of indoor positioning, in particular to an indoor positioning system based on ultrasonic ranging.

Background technique

The outdoor positioning technology represented by GPS is quite mature. However, when you are indoors, because GPS signals need to penetrate buildings, indoor positioning will continue to rely on outdoor positioning technologies such as GPS, which will make the positioning results unreliable, and the positioning accuracy is difficult to guarantee. GPS positioning results are drastically degraded by multipath effects and signal shadowing. Commonly used indoor positioning technologies include UWB technology, Wi-Fi technology, Bluetooth technology, RFID technology, etc., but most indoor positioning technology equipment is expensive. At present, the ultrasonic technology is quite mature, the production cost of the ultrasonic module is also quite low, and the ultrasonic wave has the characteristics of good directivity, which is very suitable for indoor positioning.

Between 1989 and 1992, Olivetti's laboratory developed one of the earliest indoor positioning systems, the infrared-based Active Badges positioning system, but it was not popularized due to its great flaws. Subsequently, the AT&T laboratory designed an ultrasonic-based Active Bat system on its basis. Using the TOA algorithm, the positioning can be achieved by processing at least three sets of data, and the error can be controlled within 3~4cm. Compared with western countries, domestic indoor positioning technology research is relatively late, and the technology is not mature enough, but there has been great progress and innovation. The method designed an ultrasonic ranging system that is easy to control. In 2013, Zhang Yonghong and others from Nanjing University of Information Technology removed the noise from ultrasonic signals.

Utility model content

Aiming at the deficiencies in the prior art, the utility model provides an indoor positioning system based on ultrasonic ranging, which realizes accurate positioning of the indoor environment, and has the advantages of low cost, less blind area, simple structure and flexible positioning.

To achieve the above object, the utility model adopts the following technical solutions:

An indoor positioning system based on ultrasonic ranging, comprising: a fixed base station and a mobile terminal positioning node, the fixed base station is fixedly installed on the indoor top, and the mobile terminal positioning node is set indoors;

The fixed base station includes a first main control MCU, and the first main control MCU is electrically connected with the first wireless communication module, the first ultrasonic transmitting and receiving module, and the first power supply module, and processes the data information of each module. ;

The mobile terminal positioning node includes a second main control MCU, and the second main control MCU is respectively connected with the second wireless communication module, the second ultrasonic transmitting and receiving module, the steering servo module, the electronic compass module, and the second power supply module. Electrical connection, and processing the data information of each module to complete the positioning of the mobile end node;

Wherein, the communication connection between the first wireless communication module and the second wireless communication module enables the mobile terminal positioning node to match the fixed base station when positioning needs; the second ultrasonic transmitting and receiving module is installed on the steering steering gear, so that the The steering of the steering gear enables the second ultrasonic transmitting and receiving module to transmit ultrasonic waves in different directions; the second ultrasonic transmitting and receiving module and the first ultrasonic transmitting and receiving module are connected through ultrasonic communication to realize ranging; the electronic compass module is used to obtain direction information.

In order to optimize the above technical solutions, the specific measures taken also include:

Further, the mobile terminal positioning node further includes a temperature sensor, and the temperature sensor is electrically connected with the second main control MCU.

Further, the mobile terminal positioning node further includes a WIFI communication module, the WIFI communication module is telecommunicationly connected with the second main control MCU, and the WIFI communication module is communicatively connected with the PC terminal.

Further, the frequencies of the first ultrasonic transmitting and receiving module and the second ultrasonic transmitting and receiving module are both 40KHZ.

The beneficial effects of the present invention are as follows: the application uses the combination of the steering gear and the second ultrasonic transmitting and receiving module, and at the same time obtains the distance and direction information of the positioning node of the mobile terminal in space with the help of the electronic compass module, which greatly reduces positioning. Compared with the existing multi-point positioning, the system has less dependence on the base station. Most of the modules used in this application are relatively conventional, so the construction and operation costs of the entire system are very low. Therefore, the system of the present application has a simple structure, flexible positioning, and low technical requirements in terms of construction.

Description of drawings

FIG. 1 is a schematic diagram of the distribution of fixed base stations and mobile terminal positioning nodes by position of the present invention.

FIG. 2 is a schematic diagram of the connection relationship of each module of the fixed base station of the present invention.

FIG. 3 is a schematic diagram of the connection relationship of each module of the mobile terminal positioning node of the present invention.

4 is a schematic diagram of the connection relationship of the steering steering gear of the present invention.

FIG. 5 is a schematic diagram of the position positioning relationship between the mobile terminal positioning node A and the fixed base station B in the embodiment of the present invention.

Detailed ways

The present utility model will be described in detail below with reference to the accompanying drawings.

The main technical solutions of this application are:

An indoor positioning system based on ultrasonic ranging, comprising: a fixed base station and a mobile terminal positioning node, the fixed base station is fixedly installed on the indoor top, and the mobile terminal positioning node is set indoors;

The fixed base station includes a first main control MCU, and the first main control MCU is electrically connected with the first wireless communication module, the first ultrasonic transmitting and receiving module, and the first power supply module, and processes the data information of each module;

The mobile terminal positioning node includes a second main control MCU, and the second main control MCU is electrically connected to the second wireless communication module, the second ultrasonic transmitting and receiving module, the steering servo module, the electronic compass module, and the second power supply module, respectively. Connect, and process the data information of each module so that the mobile end node completes the positioning;

The communication connection between the first wireless communication module and the second wireless communication module enables the mobile terminal positioning node to match the fixed base station when positioning needs; the second ultrasonic transmitting and receiving module is installed on the steering steering gear, so that the steering steering gear The turning of the second ultrasonic wave transmitting and receiving module enables the second ultrasonic transmitting and receiving module to transmit ultrasonic waves in different directions; the communication connection between the second ultrasonic transmitting and receiving module and the first ultrasonic transmitting and receiving module realizes ranging; the electronic compass module is used to obtain direction information.

Further, the mobile terminal positioning node also includes a temperature sensor, and the temperature sensor is electrically connected with the second main control MCU; so that the second main control MCU can use the temperature information to communicate between the first ultrasonic transmitting and receiving module and the second ultrasonic transmitting and receiving module. Correct the distance detected between them (for example, with normal temperature as the limit, the measured distance will increase by 1 cm for every one degree Celsius increase, and the measured distance will decrease by 1 cm for every one degree Celsius decrease)

Further, the mobile terminal positioning node further includes a WIFI communication module, the WIFI communication module is telecommunicationly connected with the second main control MCU, and the WIFI communication module is communicatively connected with the PC terminal for transmitting the data information in the second main control MCU to the PC terminal. PC side.

Further, the frequency of the first ultrasonic transmitting and receiving module and the second ultrasonic transmitting and receiving module is 40KHZ.

Further, the mobile terminal positioning node also includes a third ultrasonic transmitting and receiving module, and the third ultrasonic transmitting and receiving module is connected with the third ultrasonic transmitting and receiving module of another mobile terminal positioning node through ultrasonic communication, so as to realize the mutual communication between the mobile terminal positioning nodes. distance measurement;

Wherein, the second wireless communication modules between the mobile terminal positioning nodes are communicatively connected to each other, so as to realize the data interaction between the second main control MCUs.

Further, the frequency of the third ultrasonic transmitting and receiving module is 80KHZ.

The specific embodiments of the application system are as follows:

Refer to Figures 1-3. The fixed base station is composed of the following contents: LORA wireless communication module (the first wireless communication module), 40kHz ultrasonic receiving module, 40kHz ultrasonic transmitting module (receiving and transmitting are combined into the first ultrasonic transmitting and receiving module), the first power supply module, the single-chip microcomputer— - The first master control MCU. Among them, the 40kHz ultrasonic transmitting and receiving module serves for conventional positioning, and LORA is responsible for communicating with the mobile node and receiving positioning instructions from the mobile node.

Refer to Figures 1-3. The mobile terminal node consists of the following contents: electronic compass module, steering gear, 80kHz ultrasonic transmitter module, 40kHz ultrasonic transmitter module, 80kHz ultrasonic receiver module, and 40kHz ultrasonic receiver module (wherein, the 40kHz transmitter and receiver are combined into the second ultrasonic transmitter and Receiving module, 80kHz transmission and reception are combined into the third ultrasonic transmission and reception module), LORA wireless communication module (the second wireless communication module, responsible for the communication with the fixed base station), WiFi communication module (responsible for sending the positioning data together to the PC), temperature sensor, second power supply module, single-chip microcomputer - the second main control MCU. Among them, the 40kHz ultrasonic receiving and transmitting module is responsible for participating in the conventional positioning mode. The electronic compass can indicate the orientation of the node, and it is combined with the steering gear to participate in the determination of the direction. The 80kHz ultrasonic transmitter and receiver module is responsible for participating in partner positioning mode. The LORA module is responsible for communicating with fixed base stations and other mobile nodes. The temperature sensor is responsible for participating in the correction of the ranging. The Wi-Fi module is responsible for uploading the positioning information to the server.

Conventional positioning mode: Any mobile positioning node within the range of the four fixed base stations can use the conventional positioning mode. In the conventional positioning mode, the mobile positioning node first sends a positioning request, and the request is sent to the fixed base station through the LORA module. Each request carries the number of the fixed positioning base station that may be nearby, and the fixed positioning base station node is designated to enter the waiting state. Wherein, each fixed base station and mobile terminal positioning node has a unique number designation. The fixed base station enters the waiting state immediately after receiving the instruction through its own LORA module, so that the matching of the fixed base station and the mobile terminal positioning node is completed.

Refer to Figures 4-5. After the matching is completed, the mobile terminal positioning node searches for a fixed base station through the cooperation of the steering servo and the second ultrasonic transmitting and receiving module to achieve positioning. Specifically: every time the steering gear on the positioning node of the mobile terminal rotates an angle, the second ultrasonic transmitting and receiving module sends an ultrasonic signal once, and waits for a timeout period. When the timeout occurs, the fixed base station has not received a response. If it is not in the direction of the current steering gear, continue to rotate by an angle, the angle of rotation is the angle of the ultrasonic wave emitted by the ultrasonic transmitter module (the ultrasonic wave emitted by the second ultrasonic transmitter and receiver module is a wide-angle range, and the rotation of the steering gear The angle is also this wide angle), then repeat the previous operation, continue to send ultrasonic signals and wait. When the mobile node transmits ultrasonic signals and receives a response from the ultrasonic module of the fixed base station within the timeout period, measuring the waiting time in the middle and correcting the ultrasonic ranging according to the current ambient temperature can obtain the difference between the mobile node and the fixed base station. distance, and the direction of the mobile node where the fixed node is located can be obtained according to the angle of rotation of the steering gear and the pointing of the electronic compass at that time (for example, the starting direction of the steering gear is the due south pointed by the electronic compass every time, Rotate the clock by an angle, so that when there is an ultrasonic signal back, the detection direction of the ultrasonic wave relative to the south will be known), and then specify the next nearby base station, and repeat the above complete ranging process to measure the distance and direction. If there is still no ultrasonic response after the steering gear completes 360° rotation, it means that the designated fixed base station is not within the effective ranging range, so skip the fixed base station and continue to designate the next fixed base station; move through two or more fixed base stations The position of the end positioning node is determined.

It is further added that it is not accurate to search for the location of the mobile terminal positioning node only through one fixed base station, so better positioning results can be obtained through multiple base stations. Specifically: refer to Figure 5. It can be seen from the above content that the steering gear can be made to start from the true south pointed by the electronic compass every time, and rotate an angle clockwise each time, so that when there is an ultrasonic signal returning, the detection of the ultrasonic wave relative to the true south can be known. direction. In the embodiment of FIG. 5, the return signal is searched just in the due south direction of the origin. At this time, since the position of the fixed base station is fixed, and the distance between the mobile terminal positioning node and the fixed base station is known by ultrasonic ranging, it can be known that the mobile terminal positioning node must be on the circle in Figure 5 (the circle in the figure). The diameter is the distance detected). Combined with the detection direction of the ultrasonic wave (this embodiment is due south) and the detection wide angle of the ultrasonic wave, it can be known that the two extreme positions where the mobile terminal positioning node is located (A1 and A2 in Figure 5), that is, the mobile terminal positioning node must be On this inferior arc between A1 or A2 or between A1 and A2, because only at these positions can a return signal be obtained. At this time, another matching fixed base station is located in the same way, and the intersection between them is the location of the mobile terminal positioning node. In this way, the location of the mobile node is determined according to the location of the fixed base station.

Among them, after the mobile terminal positioning node knows the distance and direction information between the mobile terminal and two nearby fixed base stations, a positioning can be completed. In Figure 5, α is the transmission angle of the ultrasonic transmitter module of the mobile terminal positioning node. In the mode, it is considered that B in Figure 5 is the location of the fixed base station, A is on the inferior arc between A1 and A2, A is not marked in the figure, it can be known from geometry that ∠A1BA2 is also equal to α. When the mobile node A and a fixed base station B complete a range and direction measurement, it can be known that A is on the inferior arc between A1 and A2. When the mobile node and two fixed nodes complete the distance and direction measurement, The possible location is the intersection of two inferior arcs. It can also measure the distance with four nearby fixed base stations, and complete the positioning through the four-point positioning method. It should be appreciated that there is more than one way to complete the positioning here, as long as the positioning is completed according to the distance and direction information that have been measured. In this normal mode, since the mobile node can know the distance and direction between itself and the base station, and use the electronic compass to know its own orientation, combining these pieces of information can use fewer base stations to complete positioning, which greatly reduces positioning. blind spot.

The present application also provides a partner positioning mode other than the conventional positioning mode. In this mode, a third ultrasonic transmitting and receiving module is required. In the above-mentioned conventional positioning mode, if the nearby available positioning base stations are insufficient, the partner positioning mode can be activated, and the area where the target mobile node is located can be further narrowed with the help of other nearby mobile nodes with known positions. In partner mode, due to the lack of nearby fixed base stations, if there are other mobile nodes with known positions within the ranging range, these mobile nodes can participate in assisted positioning, and these nodes are called assisted positioning nodes. Partner positioning cannot be completed when there are no other auxiliary positioning nodes nearby. When a complete conventional positioning cannot be completed, the target mobile node will activate the partner positioning mode. In this mode, first the target mobile node has completed the interaction with the nearby fixed base stations that can be positioned, and then the target mobile node will use LORA to communicate with possible Other nearby mobile nodes send requests. After the request is sent, the 80kHz ultrasonic transmitting/receiving module (the third ultrasonic transmitting and receiving module) transmits an ultrasonic wave every time the steering gear rotates by an angle. At this time, the rotation angle of the steering gear is 80kHz ultrasonic transmission. /The angle covered by the transmission of the receiving module. After the ultrasonic wave is transmitted, the target mobile node waits for a timeout period. When the wait times out, it considers that the auxiliary positioning node is not in the direction pointed by the current steering gear, and the steering gear continues to rotate, then transmits the ultrasonic wave and waits, so Repeat, when the servo rotates 360° and still does not receive a response, it means that the auxiliary positioning node is not nearby, and continue to specify the next auxiliary positioning node. If the position of the designated auxiliary positioning node is also in an unknown state, the auxiliary positioning node will respond negatively, and the target mobile node will skip this node. After completing the request and positioning for other nearby mobile nodes, the target mobile node can try positioning again according to the known information. In this mode, the location blind area of the mobile node changes dynamically, but it is always smaller than the location blind area in the conventional location mode, which is the supplementary effect of this mode to the conventional location mode.

Among them, the installation method of 80kHz ultrasonic receiving/transmitting module is horizontal installation, the purpose is to serve the partner positioning; module.

It should be noted that the terms such as "up", "down", "left", "right", "front", "rear", etc. quoted in the utility model are only for the convenience of description and clarity, not for use In order to limit the applicable scope of the present invention, the change or adjustment of the relative relationship shall also be regarded as the applicable scope of the present invention without substantially changing the technical content.

The above are only the preferred embodiments of the present utility model, and the protection scope of the present utility model is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present utility model belong to the protection scope of the present utility model. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (4)

1. an indoor positioning system based on ultrasonic ranging, is characterized in that, comprises: fixed base station and mobile terminal positioning node, fixed base station is fixedly installed on indoor top, and mobile terminal positioning node is arranged in indoor; The fixed base station includes a first main control MCU, and the first main control MCU is electrically connected with the first wireless communication module, the first ultrasonic transmitting and receiving module, and the first power supply module, and processes the data information of each module. ; The mobile terminal positioning node includes a second main control MCU, and the second main control MCU is respectively connected with the second wireless communication module, the second ultrasonic transmitting and receiving module, the steering servo module, the electronic compass module, and the second power supply module. Electrical connection, and processing the data information of each module to complete the positioning of the mobile end node; Wherein, the communication connection between the first wireless communication module and the second wireless communication module enables the mobile terminal positioning node to match the fixed base station when positioning needs; the second ultrasonic transmitting and receiving module is installed on the steering steering gear, so that the The steering of the steering gear enables the second ultrasonic transmitting and receiving module to transmit ultrasonic waves in different directions; the second ultrasonic transmitting and receiving module and the first ultrasonic transmitting and receiving module are connected through ultrasonic communication to realize ranging; the electronic compass module is used to obtain direction information. 2 . The indoor positioning system based on ultrasonic ranging according to claim 1 , wherein the mobile terminal positioning node further comprises a temperature sensor, and the temperature sensor is electrically connected to the second main control MCU. 3 . 3 . The indoor positioning system based on ultrasonic ranging according to claim 1 , wherein the mobile terminal positioning node further comprises a WIFI communication module, and the WIFI communication module is telecommunicationly connected with the second main control MCU, 3 . And the WIFI communication module is in communication connection with the PC terminal. 4 . The indoor positioning system based on ultrasonic ranging according to claim 1 , wherein the frequency of the first ultrasonic transmitting and receiving module and the second ultrasonic transmitting and receiving module are both 40KHZ. 5 .

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