Outdoor nursing positioning system and positioning method

Abstract

The invention relates to an outdoor nursing positioning system and method, and belongs to the field of positioning equipment. A positioning module is worn on a nursed person, a positioning base station is arranged on an unmanned aerial vehicle, the positioning module transmits a wireless signal to the positioning base station, and after the positioning base station receives the wireless signal, the relative position of the positioning module and the positioning base station is calculated; and inversely solving the absolute position of the positioning module according to the absolute position of the unmanned aerial vehicle and the relative position of the positioning module and the positioning base station. The absolute position of the nursed person can be accurately determined, the unmanned aerial vehicle takes the absolute position of the nursed person as a destination to carry out real-time accompanying flight, the unmanned aerial vehicle can follow the nursed person all the time, and the nursing effect is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of positioning equipment, in particular to an outdoor care positioning system and a positioning method. Background Art

[0002] The elderly and children have limited behavioral abilities and need care during outdoor activities. Since guardians have limited energy, it is difficult to always pay attention to the location and movements of the elderly or children, so drone care systems have emerged.

[0003] The existing drones are used for accompanying flights during care. The drones must move with the movement of the person being cared for. Therefore, the positioning between the person being cared for and the drone is crucial. There are two existing positioning methods. One is video tracking collaborative positioning, that is, when the person being cared for moves, the drone's onboard camera can be used for face recognition, and then the outdoor activities of the elderly (such as trajectory, help, lost, etc.) are tracked throughout the whole process. In order to ensure that the onboard camera can accurately capture the target elderly during the tracking process, near-low-altitude frontal face capture is generally used for accompanying flight. Once lost, the elderly care service cannot be completed. This method relies heavily on face recognition for tracking. Since both humans and drones are moving targets, there is a problem of low recognition rate, and it is easy to lose during the tracking process; in addition, it is easily interfered by other pedestrians on the ground, and the expected target person being cared for cannot be successfully identified, resulting in a loss of tracking. Therefore, this method is mainly used in tracking scenarios with a single target. The other is GPS / Beidou tracking collaborative positioning, that is, the elderly wear GPS / Beidou positioning modules bound to their identity information to achieve absolute positioning, and after fusing with the absolute position of the drone, human-machine collaborative relative positioning can be achieved, which can effectively improve the problem of low face recognition rate. Its disadvantage is that due to the obstruction of urban high-rise buildings and the wearing of personnel, GPS / Beidou positioning will produce large errors, making it impossible to achieve accurate positioning of the sidewalk, and ultimately making collaborative positioning difficult. In addition, the module has high power consumption, which is not conducive to long-term use. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an outdoor care positioning system and a positioning method to reduce power consumption and improve positioning accuracy.

[0005] To solve the above problems, the technical solution adopted by the present invention is: an outdoor care positioning method, in which a positioning module is worn on the person being cared for, a positioning base station is set on the drone, the positioning module transmits a wireless signal to the positioning base station, and after the positioning base station receives the wireless signal, the relative position of the positioning module and the positioning base station is calculated, and then the absolute position of the positioning module is reversed according to the absolute position of the drone and the relative position of the positioning module and the positioning base station.

[0006] Furthermore, the positioning base station includes a plurality of antennas evenly distributed on a circumference, and there is a spacing between two adjacent antennas.

[0007] Furthermore, multiple antennas simultaneously receive the wireless signal transmitted by the positioning module, and one of the antennas is used as a reference antenna. The reference antenna extracts the phase of the wireless signal as the reference phase, and the relative position of the positioning module and the positioning base station is calculated based on the phase difference between the phase of the wireless signal extracted by other antennas and the reference phase.

[0008] Furthermore, the wireless signal transmitted by the positioning module is an ultra-wideband signal.

[0009] The outdoor care positioning system includes a drone and a positioning module for transmitting wireless signals. The drone is provided with a positioning base station for receiving wireless signals, a processor for positioning calculation, a network module for signal transmission, and a power module for power supply. The positioning base station, the network module, and the power module are all connected to the processor.

[0010] Furthermore, the positioning base station includes a plurality of reference antennas and control antennas uniformly distributed in a circle around the reference antennas.

[0011] Furthermore, there are 8 reference antennas.

[0012] Furthermore, the processor is connected to a storage module.

[0013] Furthermore, the network module includes a wired network module and a wireless network module, and both the wired network module and the wireless network module are connected to the processor.

[0014] The beneficial effects of the present invention are as follows: the positioning module adopted by the present invention can transmit ultra-wideband signals, and the ultra-wideband has the characteristics of low power consumption and high-speed transmission. The positioning module has low power consumption and long battery life.

[0015] The positioning method of the present invention can accurately determine the absolute position of the person being cared for. The drone takes the absolute position of the person being cared for as the destination for real-time accompanying flight. The drone can always follow the person being cared for, thereby ensuring the care effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of an outdoor care positioning system of the present invention;

[0017] Figure 2 It is a diagram of the angles of the wireless signal when it reaches different wires;

[0018] Figure 3 It is a schematic diagram of the position relationship between the antenna array and the positioning module during positioning;

[0019] Figure 4 yes Figure 3 Enlarged schematic diagram of the antenna array. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0021] The outdoor care positioning system of the present invention is as follows: Figure 1 As shown, it includes a drone 2 and a positioning module 1 for transmitting wireless signals. The drone 2 is provided with a positioning base station 3 for receiving wireless signals, a processor 4 for positioning calculation, a network module 5 for signal transmission and a power module 6 for power supply. The positioning base station 3, the network module 5 and the power module 6 are all connected to the processor 4.

[0022] The positioning module 1 is worn on the person being cared for, and the positioning module 1 can be prepared as a commonly used wearable device such as a bracelet, or the positioning module 1 can be integrated with a traditional wearable device.

[0023] The drone 2 can use the existing technology, and the positioning base station 3 is used to receive the wireless signal sent by the positioning module 1, so that the processor 4 can calculate the relative position of the positioning module 1 and the positioning base station 3 according to the wireless signal. The relative position of the positioning module 1 and the positioning base station 3 is the relative position of the person under care and the drone 2. The absolute position of the drone 2 is known, so the processor 4 can calculate the absolute position of the person under care according to the absolute position of the drone 2 and the relative position of the person under care and the drone 2, and then take the absolute position of the person under care as the destination and fly towards the person under care to achieve companion flight. The present invention can continuously adjust the position of the drone 2 according to the change of the position of the person under care by receiving the wireless signal sent by the positioning module 1 in real time and performing positioning, so that the person under care is always under the monitoring of the drone 2, and effective companion flight is achieved.

[0024] The power module 6 is used to supply power to each component, and a battery can be used. The network module 5 is used to communicate with the terminal device, and can transmit the location, activity trajectory and other information of the person being cared for to the terminal device, which can be the guardian's mobile phone, computer, tablet and other devices.

[0025] In addition, the processor 4 is also connected to a storage module 7, which can store basic information of the person being cared for, etc. A camera can also be set on the drone 2 to capture the activity images of the person being cared for, and the storage module 7 stores the activity images of the caregiver.

[0026] The network module 5 includes a wired network module 51 and a wireless network module 52, both of which are connected to the processor 4. The wireless network module 52 communicates with the terminal device wirelessly, and can transmit the location information of the person being cared for to the terminal device. The wired network module 51 is connected to the terminal device via a network cable, and can regularly transmit information such as the activity trajectory of the person being cared for to the terminal device.

[0027] The positioning module 1 of the present invention adopts an ultra-wideband signal source and can transmit ultra-wideband signals. Ultra-wideband is a carrier-free communication technology that uses discontinuous narrow pulses. The device transmits low power, so it has the characteristics of low power consumption and strong endurance. It also has the advantages of fast transmission speed, strong anti-interference ability, low cost, etc.

[0028] The outdoor care positioning method of the present invention is that the person being cared for wears a positioning module 1, and a positioning base station 3 is set on the drone 2. The positioning module 1 transmits a wireless signal to the positioning base station 3. After the positioning base station 3 receives the wireless signal, the relative position of the positioning module 1 and the positioning base station 3 is calculated, and then the absolute position of the positioning module 1 is reversed according to the absolute position of the drone 2 and the relative position of the positioning module 1 and the positioning base station 3.

[0029] The positioning base station 3 of the present invention includes multiple reference antennas and reference antennas uniformly distributed in a circumference around the reference antennas. All antennas are vertically arranged, and there is a spacing between two adjacent reference antennas. The reference antennas are specifically 8, and can also be 9, 10, etc. Multiple antennas simultaneously receive the wireless signal transmitted by the positioning module 1. Due to the different positions of the antennas, the phases of the wireless signals received by different antennas are different, that is, the wireless signals received by different antennas have a phase difference. The relative position of the positioning module 1 and the positioning base station 3 can be calculated using this phase difference.

[0030] Multiple antennas simultaneously receive the wireless signal transmitted by the positioning module 1, and one of the antennas is used as a reference antenna. The reference antenna extracts the phase of the wireless signal as the reference phase, and the relative position of the positioning module 1 and the positioning base station 3 is calculated based on the phase difference between the phase of the wireless signal extracted by other antennas and the reference phase.

[0031] Specifically, the present invention uses two coordinate systems for positioning, one is an absolute coordinate system, which is fixed, and the positions of the positioning module 1 and the drone 2 in the absolute coordinate system are the absolute positions, and the other is a relative coordinate system, which moves with the movement of the drone 2. In the present invention, the reference antenna is used as the coordinate origin, the x-axis and y-axis are horizontal, and the z-axis is vertical, such as Figure 4 shown.

[0032] like Figure 2 As shown, the distance between the two antennas is d, and the signal waves received by the two antennas have a distance differenceΔ L, Δ L and phase difference Δ φ has the following relationship:

[0033]

[0034] Where λ is the wavelength of the wireless signal.

[0035] Since the distance R from the tag to the base station is much larger than the distance d of the antenna array, the maximum distance difference is the antenna distance d of the antenna array. The angle θ is defined as the angle between the incoming wave and the two antenna arrays, and the following relationship exists:

[0036]

[0037] Pick (According to experience, the best effect is achieved when d is half the wavelength), then:

[0038]

[0039] The phases of signals received by different antennas at the same time are somewhat different. The schematic diagram of antenna array and spatial positioning is shown in Figure 3 and Figure 4 shown.

[0040] In the figure, the reference antennas C1 are evenly distributed on the circle, and the circle C2 below is the coverage of the base station. The radius R of the circle C2 is set to twice the height H of the drone 2. 1, 2, 3, 4, 5, 6, 7, 8 represent 8 reference antennas, and 9 represents the reference antenna.

[0041] The unit vector formed between each reference antenna and the reference antenna is denoted as μ i (i=1,2...n, n is the number of control antennas), the coordinate origin and the test point T (T is the location of the positioning module 1, which is also the location of the person being cared for) form a vector r. The unit vector is as follows:

[0042] μ i =(cosα i ,sinα i ,0)

[0043] Among them, α i represents the unit vector μ i The angle with the x-axis. The test point T vector is as follows: r = (x, y, z). According to the inner product definition:

[0044]

[0045] Among them, θ i Let r and μ be vectors i The angle between them can be deduced:

[0046]

[0047] Define the angle between vector r and the x-axis as β x , the angle with the y-axis is β y , the angle with the z-axis is β z , then the following conditions must be met:

[0048]

[0049] Further simplifying:

[0050] cosθ i =cosβ x ·cosα i +cosβ y ·sinα i

[0051]

[0052] The matrix [cosα i ,sinα i ] is denoted as matrix A,

[0053] matrix Denoted as matrix X,

[0054] The matrix cosθ i Denoted as matrix L,

[0055] Taking different values ​​of i, according to the matrix equation, solve AX=L, X=(A T A) -1 A T L, cosβ can be easily solved x , cosβ y . Then solve the x, y, and z coordinates.

[0056] According to the spatial relationship:

[0057]

[0058] Due to cosβ x , cosβ y It has been obtained in the previous step, and cosβ can be obtained more easily here z Since the height H between the positioning base station 3 and the positioning module 1 is known, therefore:

[0059]

[0060] Similarly, it is relatively easy to find the modulus of the vector r composed of the coordinate origin and the test point T Therefore, the final test point coordinates are:

[0061]

[0062] x and y are the coordinates of the person being cared for in the relative coordinate system, thus realizing human-machine positioning.

[0063] After the relative coordinates of the person being cared for are calculated, their absolute coordinates can be calculated.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Outdoor care positioning method, characterized by: A positioning module (1) is worn on the person being cared for, and a positioning base station (3) is arranged on the drone (2). The positioning module (1) transmits a wireless signal to the positioning base station (3). After receiving the wireless signal, the positioning base station (3) calculates the relative position of the positioning module (1) and the positioning base station (3), and then reversely solves the absolute position of the positioning module (1) based on the absolute position of the drone (2) and the relative position of the positioning module (1) and the positioning base station (3).

2. The outdoor care positioning method according to claim 1, characterized in that: The positioning base station (3) comprises a plurality of antennas evenly distributed on a circumference, with a spacing between two adjacent antennas.

3. The outdoor care positioning method according to claim 2, characterized in that: Multiple antennas simultaneously receive wireless signals transmitted by a positioning module (1), one of the antennas is used as a reference antenna, the reference antenna extracts the phase of the wireless signal as the reference phase, and the relative position of the positioning module (1) and the positioning base station (3) is calculated based on the phase difference between the phase of the wireless signal extracted by other antennas and the reference phase.

4. The outdoor care positioning method according to claim 1, characterized in that: The wireless signal emitted by the positioning module (1) is an ultra-wideband signal.

5. Outdoor care positioning system, characterized by: The invention comprises an unmanned aerial vehicle (2) and a positioning module (1) for transmitting wireless signals. The unmanned aerial vehicle (2) is provided with a positioning base station (3) for receiving wireless signals, a processor (4) for positioning calculation, a network module (5) for signal transmission, and a power supply module (6) for power supply. The positioning base station (3), the network module (5) and the power supply module (6) are all connected to the processor (4).

6. The outdoor care positioning system according to claim 5, characterized in that: The positioning base station (3) comprises a plurality of reference antennas and control antennas uniformly distributed in a circumferential shape around the reference antennas.

7. The outdoor care positioning system according to claim 6, characterized in that: There are 8 reference antennas.

8. The outdoor care positioning system according to claim 5, characterized in that: The processor (4) is connected to a storage module (7).

9. The outdoor care positioning system according to claim 5, characterized in that: The network module (5) comprises a wired network module (51) and a wireless network module (52), and both the wired network module (51) and the wireless network module (52) are connected to the processor (4).

Images