A Spatial Pointing and Positioning Method and Device Based on UWB

Abstract

The present invention discloses a spatial pointing and positioning method and device based on UWB, including a pointing device and a pointed device. At least two UWB antennas of the pointing device arranged front and back and an IMU inertial navigation chip are provided on the pointing device. At least two UWB anchors are provided on the pointed device at intervals, and at least one UWB anchor antenna is provided on the UWB anchor. The first azimuth angle α is obtained through the IMU inertial navigation chip of the pointing device imu , and the second azimuth angle α is calculated by cooperating the UWB antenna of the pointing device and the UWB anchor antenna through the distance and phase difference obtained in the DS-TWR ranging process uwb . Finally, a fusion algorithm is used to fuse the first azimuth angle α imu and the second azimuth angle α uwb to obtain the accurate pointing attitude of the pointing device, and the coordinates of the projection point of the pointing device on the pointed device are calculated according to the pointing attitude

Description

Technical Field

[0001] The present invention relates to the field of interaction, and particularly relates to a spatial pointing and positioning method and device based on UWB. Background Art

[0002] In the traditional interaction method of a TV screen, there are often only the up, down, left, and right buttons of the remote control. In some scenarios that require quick selection and input, such as inputting using a virtual keyboard, the input efficiency of the remote control is very low. Currently, there are already some pointing remote controls using UWB technology that can quickly move the cursor to the desired target, greatly improving the interaction efficiency. However, existing products also have some defects:

[0003] 1. The antennas of existing UWB pointing remote controls on the market are arranged horizontally, occupying a large horizontal area, resulting in the product being only in the form of a remote control and having a large volume. In addition, the head of the remote control will bulge slightly to place the antenna, affecting the aesthetics;

[0004] 2. The usage area of existing UWB pointing remote controls is often in front of the screen, and the pointing effect is not good on the side of the screen, resulting in limitations in the applicable scenarios. For example, in a meeting or teaching scenario, the speaker often needs to hold a tool and stand on the side of the screen to make some marking operations on the interface, and existing products are difficult to meet the requirements. Summary of the Invention

[0005] The main purpose of the present invention is to provide a spatial pointing and positioning method and device based on UWB that not only has a normal usage range in front of the screen, but also achieves the same accuracy requirements in the usage scenario on the side of the screen, and can meet the usage needs of various pointing devices including remote controls and teaching pointer pens.

[0006] The present invention provides a spatial pointing and positioning method and device based on UWB, including a pointing device and a pointed device. At least two pointing device UWB antennas arranged front and back are provided on the pointing device, and at least two UWB anchors are provided on the pointed device at intervals, and a spatial coordinate system based on the UWB anchors is established through the two UWB anchors;

[0007] The pointing device performs DS-TWR ranging with the UWB anchors respectively, and obtains the coordinates (x remote , y remote , z remote ) of the pointing device in the spatial coordinate system of the UWB anchors, and obtains phase differences pdoa1 and pdoa2 through the pointing device UWB antennas in the pointing device;

[0008] An IMU inertial navigation chip is provided inside the pointing device, and the included angle θ between the pointing device and the horizontal plane where it is located and the first azimuth angle α calculated by inertial navigation can be obtained based on the IMU inertial navigation chip. imu ;

[0009] Based on the phase differences pdoa1 and pdoa2 and the coordinates (x remote , y remote , z remote ), the attitude vector based on the pointing device can be calculated, and the second azimuth angle α can be obtained. uwb ;

[0010] A fusion algorithm is used to fuse the first azimuth angle α imu and the second azimuth angle α uwb to obtain the accurate pointing attitude of the pointing device, and the projection point coordinates of the pointing device on the pointed device are calculated according to the pointing attitude.

[0011] Preferably, the IMU inertial navigation chip can obtain the attitude rotation matrix R of the pointing device through an attitude algorithm, and obtain a unit vector pointing from the tail to the head according to the installation attitude of the IMU inertial navigation chip inside the pointing device. And the unit vector is converted into a unit vector in the geodetic coordinate system so as to obtain the included angle θ between the pointing device and the horizontal plane z = z remote , and the first azimuth angle α calculated by inertial navigation. imu .

[0012] Preferably, the end point coordinates of the attitude vectors that satisfy the signal phase difference relationship between the pointing device and the two UWB anchors are calculated respectively, and the solution of their intersection is taken as the end point coordinates (x, y, z) of the attitude vector based on the pointing device.

[0013] Preferably, the fusion algorithm is the kalman algorithm.

[0014] A device for a UWB-based spatial pointing and positioning method, the device includes a pointed device, two UWB anchors arranged at intervals on the pointed device, and a pointing device;

[0015] The UWB anchor includes an anchor UWB baseband and at least one anchor UWB antenna;

[0016] The pointing device includes a pointing device UWB baseband, at least two pointing device UWB antennas arranged front and back, a Bluetooth SoC, and an IMU inertial navigation chip.

[0017] Preferably, two anchor UWB antennas are provided in at least one of the UWB anchors, and when the UWB anchor provided with the two anchor UWB antennas performs DS-TWR ranging with the pointing device, the height z of the pointing device in the space coordinate system based on the UWB anchor can be calculated. remote 。

[0018] Preferably, the pointing device is a remote control or a pointer pen.

[0019] Preferably, the UWB anchor is provided in the device to be pointed.

[0020] Preferably, the UWB anchor is an external device that can be clipped, set or fixed on the device to be pointed, and the external device can be located on both sides of the device to be pointed, on the upper edge of the device to be pointed, on the lower edge of the device to be pointed or on the periphery of the device to be pointed.

[0021] Preferably, an acceleration sensor ACC is provided in the UWB anchor. The attitude at the time of its own installation can be obtained through the acceleration sensor ACC, so that when the UWB anchor is installed, the attitude can be adjusted according to the antenna pattern, and the antenna pattern faces the pointing device better to improve the system performance. During the process of adjusting the attitude, the UWB anchor can calculate the current attitude angle in real time through the acceleration sensor ACC, so as to compensate when calculating the height z of the pointing device in the space coordinate system based on the UWB anchor. remote when compensating.

[0022] The beneficial effects of the UWB-based spatial pointing and positioning method and device of the present invention are as follows:

[0023] 1. Compared with the design of dual antennas on the front side of the pointing device in the prior art, it can be applied to products such as long pointer pens, and the appearance is more beautiful than the existing design, so it can be applied to more usage scenarios.

[0024] 2. In addition to being applicable to new products, if the installation and setting of external devices are adopted, it can be applied to old display devices such as televisions and projectors, so as to empower traditional products and make them have the same functions as new devices.

[0025] 3. Higher accuracy and more applicable scenarios, and it can be adapted to usage scenarios such as closer demonstrations, so as to meet the usage needs of more customers.

[0026] 4. The azimuth angle is calculated by two methods, and the two calculated azimuth angles are fused by the kalman algorithm, so that the finally calculated azimuth angle is more accurate. Description of the Drawings

[0027] Figure 1 This is the usage state diagram of the UWB-based spatial pointing positioning method and device of the present invention;

[0028] Figure 2 This is the schematic structural diagram of one embodiment of the UWB anchor point of the UWB-based spatial pointing positioning method and device of the present invention;

[0029] Figure 3 This is the schematic structural diagram of another embodiment of the UWB anchor point of the UWB-based spatial pointing positioning method and device of the present invention;

[0030] Figure 4 This is the schematic structural diagram of the pointing device of the UWB-based spatial pointing positioning method and device of the present invention;

[0031] Reference numerals in the figure: 1, device to be pointed at; 2, pointing device; 3, UWB anchor point; 21, UWB baseband of the pointing device; 22, Bluetooth SoC; 23, IMU inertial navigation chip; 24, UWB antenna of the pointing device; 31, UWB baseband of the anchor point; 32, acceleration sensor ACC; 33, UWB antenna of the anchor point.

[0032] The realization, functional features and advantages of this objective will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0033] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Refer to Figure 1 、 Figure 2 and Figure 4 An embodiment of the UWB-based spatial pointing positioning method and device of the present invention is proposed:

[0035] A UWB-based spatial pointing positioning method and device, the device includes a device to be pointed at 1, two UWB anchor points 3 arranged on both sides of the device to be pointed at 1, and a pointing device 2. The UWB anchor point 3 includes an anchor point UWB baseband 31 and an anchor point UWB antenna 33. The pointing device 2 includes a pointing device UWB baseband 21, two UWB antennas 24 of the pointing device arranged front and back, a Bluetooth SoC 22, and an IMU inertial navigation chip 23.

[0036] In this embodiment, the pointed device 1 is a television, with two UWB anchor points 3 installed inside the television, with a fixed distance d between them. Alternatively, the pointed device 1 could be a projector, with the UWB anchor points being two external devices that can be clamped or fixed to either side of the pointed device 1. The two external devices communicate with each other to determine the distance d between them, and also determine the pointed surface based on the midline between them. This surface is equivalent to the television screen and the projector screen. The external device can be paired with the pointing device 2 via Bluetooth. Pointing device 2 obtains information such as the battery level of the external device via the Bluetooth connection.

[0037] The pointing device 2 performs DS-TWR ranging with the two UWB anchor points 3, and obtains the phase differences pdoa1 and pdoa2 and distances r1 and r2 between the pointing device 2 and the two UWB anchor points 3. A coordinate system is established with the center of the pointed device 1, and the coordinates of the UWB anchor points 3 on the left and right sides are:

[0038]

[0039] In this embodiment, the height of the pointing device 2 relative to the pointed device 1 in the use environment does not need to change greatly. Otherwise, the second embodiment of this patent is adopted. Therefore, since the height of the pointing device 2 is within a certain range most of the time, the height of the pointing device 2 is set to 0. remote It is also set as a known condition, that is, a fixed value, according to the following formula:

[0040]

[0041] And calculate the coordinates of pointing device 2 (x remote ,y remote ,z remote ).

[0042] The pointing device 2 contains a 6-axis IMU inertial navigation chip 23. The attitude rotation matrix R of the pointing device 2 can be obtained through the attitude algorithm. According to the installation attitude of the IMU inertial navigation chip 23 inside the pointing device 2, the local coordinate system is abstracted into a unit vector pointing from the tail to the head. Thus, the vector is converted to the vector in the geodetic coordinate system Therefore, the rolling state of the pointing device 2 can be ignored, and the pointing device 2 and the horizontal plane z=z remote The angle θ, and the first azimuth angle α calculated by inertial navigation imu .

[0043] Since the first azimuth angle obtained by the pointing device 2 through inertial navigation will have cumulative errors, it is assumed that the attitude vector of the pointing device The coordinates of the end point are (x,y,z).

[0044] z = z remote +sinθ

[0045]

[0046] The phase difference obtained by DS - TWR ranging is pdoa1, and the incident angle of the signal received from the left UWB anchor 3 on the pointing device is:

[0047]

[0048] where λ is the wavelength of the UWB signal, and d ant is the distance between the two UWB antennas 24 of the pointing device before and after. Similarly, for the triangle formed by the pointing device vector and the anchor coordinates, the same angle should also be calculated using the cosine theorem:

[0049]

[0050] According to the above formula, the end coordinates (x1, y1, z1) of the attitude vector of the pointing device 2 can be calculated.

[0051] Since there may be two solutions for the result of the above calculation, use the same algorithm to calculate (x2, y2, z2) through the right UWB anchor 3, so as to eliminate the ambiguity according to the two obtained results and obtain the accurate end coordinates (x, y, z) of the attitude vector of the pointing device 2, and the second azimuth angle α of the pointing device 2 can be obtained through the formula uwb

[0052] α uwb = atan2(y, x)

[0053] The second azimuth angle α of the pointing device calculated using UWB uwb , and the first azimuth angle α originally calculated by inertial navigation imu , are fused using the kalman algorithm. Among them, α uwb has a large measurement jitter but no cumulative error, while α imu has a very small measurement jitter but has a cumulative error. Fusing the two ensures the stability and accuracy of the attitude vector of the pointing device.

[0054] The pointing device 2 calculates the projection point coordinates on the screen through the attitude vector, and feeds the coordinates back to the screen through Bluetooth or other communication means, and finally displays an accurately positioned cursor on the screen to complete the function of absolute pointing.

[0055] Refer to Figure 1 , Figure 3 and Figure 4, another embodiment of the UWB-based spatial pointing and positioning method and device of the present invention is proposed:

[0056] A UWB-based spatial pointing and positioning method and device. The device includes a device to be pointed 1, two UWB anchors 3 arranged on both sides of the device to be pointed 1, and a pointing device 2. The UWB anchor 3 includes an anchor UWB baseband 31, two anchor UWB antennas 33, and an acceleration sensor ACC32. In actual use, one UWB anchor 3 can adopt a single anchor UWB antenna 33, and the other UWB anchor 3 can adopt the design of two anchor UWB antennas 33. The design of both using dual antennas will obtain higher accuracy and better stability. The pointing device 2 includes a pointing device UWB baseband 21, two pointing device UWB antennas 24 arranged front and back, a Bluetooth SoC 22, and an IMU inertial navigation chip 23.

[0057] In this embodiment, the device to be pointed 1 is a TV, and the two UWB anchors 3 are arranged inside the TV and the distance d between them is fixed. In addition to this solution, the device to be pointed 1 can also be a projector, and the UWB anchors 3 can be two external devices that can be clamped or fixed on both sides of the device to be pointed 1. The two external devices communicate with each other to obtain the distance d between them, and obtain the pointed surface based on the midline of the two, and this pointed surface is equivalent to the screen of the TV and the curtain of the projector. The external device can be Bluetooth paired with the pointing device 2. The pointing device 2 obtains information such as the power of the external device through Bluetooth connection.

[0058] In addition, for the UWB anchor 3 existing as an external device, the acceleration sensor ACC32 can obtain its own installation attitude, so that when the UWB anchor 3 is installed, it can adjust its attitude according to the antenna pattern, and face the pointing device 2 with a better orientation of the antenna pattern to improve the system performance. During the process of adjusting the attitude, the UWB anchor 3 can calculate the current attitude angle in real time through the acceleration sensor ACC32, so as to compensate when calculating the height z of the pointing device in the space coordinate system based on the UWB anchor. remote when compensating.

[0059] The pointing device 2 performs DS-TWR ranging with the UWB anchors 3 respectively, and obtains the phase differences pdoa1 and pdoa2 and distances r1 and r2 between the pointing device 2 and the two UWB anchors 3. And because the dual-antenna design is adopted in this embodiment, the PDoA received by the UWB anchor 3 from the pointing device 2 can also be obtained. remote Taking the center of the device to be pointed 1 as the coordinate system, the coordinates of the UWB anchors on the left and right sides are respectively:

[0060]

[0061] And according to the following formula:

[0062]

[0063] where d anc is the antenna spacing between two anchor UWB antennas 33 on a single UWB anchor. From the above formula, the coordinates (x remote , y remote , z remote ) of the pointing device 2 are calculated.

[0064] The pointing device contains a 6-axis IMU inertial navigation chip 23 inside, and the attitude rotation matrix R of the remote control can be obtained through the attitude algorithm. According to the installation attitude of the IMU inertial navigation chip 23 inside the pointing device 2, a unit vector pointing from the tail to the head is abstracted in the local coordinate system so as to convert this vector into a vector in the geodetic coordinate system Thus, the roll state of the attitude of the pointing device 2 can be ignored, and the angle θ between the pointing device 2 and the horizontal plane z = z remote , and the first azimuth angle α calculated by inertial navigation are obtained imu .

[0065] Since there will be an accumulated error in the first azimuth angle obtained by the pointing device 2 through inertial navigation, it is assumed that the end coordinates of the attitude vector of the pointing device 2 are (x, y, z). Where

[0066] z = z remote + sinθ

[0067]

[0068] The phase difference obtained by DS-TWR ranging is pdoa1, and the signal incident angle received by the pointing device 2 from the left UWB anchor 3 is:[[]]

[0069]

[0070] where λ is the wavelength of the UWB signal, and d ant is the distance between the front and rear UWB antennas 24 of the pointing device 2. Similarly, for the triangle formed by the pointing device vector and the anchor coordinates, the same angle should also be calculated using the cosine theorem:[[]]

[0071]

[0072] According to the above formula, the end coordinates (x1, y1, z1) of the attitude vector of the pointing device 2 can be calculated.

[0073] Since there may be two solutions for the result of the above calculation, the same algorithm is used to calculate (x2, y2, z2) through the right UWB anchor 3, so as to eliminate the ambiguity according to the two obtained results, and obtain the end coordinates (x, y, z) of the attitude vector of the pointing device 2 accurately, and the second azimuth angle α of the pointing device 2 can be obtained through the formula uwb

[0074] α uwb = atan2(y, x)

[0075] The second azimuth angle α of the pointing device 2 calculated by UWB uwb , and the first azimuth angle α calculated by the original inertial navigation imu , are fused using the kalman algorithm, where α uwb has a large measurement jitter but no cumulative error, while α imu has a very small measurement jitter but has a cumulative error. Fusing the two ensures the stability and accuracy of the attitude vector of the pointing device.

[0076] The pointing device 2 calculates the projection point coordinates on the screen through the attitude vector, and feeds the coordinates back to the screen through Bluetooth or other communication means, and finally displays a cursor with accurate position on the screen to complete the function of absolute pointing.

[0077] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A spatial pointing and positioning method based on UWB, characterized in that it includes a pointing device and a pointed device. At least two UWB antennas of the pointing device are arranged front and back. At least two UWB anchors are arranged at intervals on the pointed device, and a spatial coordinate system based on the UWB anchors is established through the two UWB anchors; The pointing device respectively performs DS-TWR ranging with the UWB anchors and obtains the coordinates of the pointing device in the spatial coordinate system of the UWB anchors , and obtains a phase difference through the pointing device UWB antenna in the pointing device and ; An IMU inertial navigation chip is provided inside the pointing device, and the angle between the pointing device and the horizontal plane where it is located can be obtained according to the IMU inertial navigation chip and the first azimuth angle calculated by inertial navigation ; Based on the phase difference and as well as the coordinates it is possible to calculate the attitude vector based on the pointing device and obtain the second azimuth angle ; The first azimuth angle is fused using a fusion algorithm and the second azimuth angle to obtain the accurate pointing attitude of the pointing device, and calculate the coordinates of the projection point of the pointing device on the pointed device according to the pointing attitude; An acceleration sensor ACC is provided inside the UWB anchor. The attitude when the UWB anchor is installed can be obtained through the acceleration sensor ACC, so that when the UWB anchor is installed, its attitude can be adjusted according to the antenna pattern, and the antenna pattern can better face the pointing device to improve the system performance. During the attitude adjustment process, the UWB anchor can calculate the current attitude angle in real time through the acceleration sensor ACC, so as to compensate when calculating the height of the pointing device in the space coordinate system based on the UWB anchor. for compensation.

2. The UWB-based spatial pointing positioning method according to claim 1, characterized in that, The IMU inertial navigation chip can obtain the attitude rotation matrix R of the pointing device through an attitude algorithm, and obtain a unit vector pointing from the tail to the head according to the installation attitude of the IMU inertial navigation chip inside the pointing device , and the unit vector is converted into a unit vector in the geodetic coordinate system , so as to obtain the included angle between the pointing device and the horizontal plane where it is located , as well as the first azimuth angle of inertial navigation calculation .

3. The UWB-based spatial pointing and positioning method according to claim 1, wherein Calculate the end coordinates of the attitude vectors that satisfy the signal phase difference relationship between the pointing device and the two UWB anchors respectively, and take the intersection solution of the two as the end coordinates of the attitude vector based on the pointing device. .

4. The UWB-based spatial pointing and positioning method according to claim 3, characterized in that, The fusion algorithm is the Kalman algorithm.

5. A device for a spatial pointing and positioning method based on UWB, characterized in that the device includes a pointed device, two UWB anchors arranged at intervals on the pointed device, and a pointing device; the UWB anchor includes an anchor UWB baseband and at least one anchor UWB antenna; the pointing device includes a pointing device UWB baseband, at least two UWB antennas of the pointing device arranged front and back, a Bluetooth SoC, and an IMU inertial navigation chip, An acceleration sensor ACC is provided inside the UWB anchor. The attitude when the UWB anchor is installed can be obtained through the acceleration sensor ACC, so that when the UWB anchor is installed, its attitude can be adjusted according to the antenna radiation pattern, and the antenna radiation pattern can better face the pointing device to improve the system performance. During the attitude adjustment process, the UWB anchor can calculate the current attitude angle in real time through the acceleration sensor ACC, so as to compensate when calculating the height of the pointing device in the space coordinate system based on the UWB anchor. for compensation.

6. The apparatus for the UWB-based spatial pointing positioning method according to claim 5, wherein At least two anchor UWB antennas are provided inside at least one of the UWB anchors, and when the UWB anchor provided with the two anchor UWB antennas performs DS-TWR ranging with the pointing device, the height of the pointing device in the space coordinate system based on the UWB anchor can be calculated. .

7. The device for the UWB-based spatial pointing and positioning method according to claim 5, characterized in that the pointing device is a remote controller or a pointer pen.

8. The apparatus for the UWB-based spatial pointing and positioning method according to claim 5, characterized in that, The UWB anchor is arranged inside the pointed device.

9. The apparatus for the UWB-based spatial pointing and positioning method according to claim 5, wherein The UWB anchor is an external device that can be clamped, arranged or fixed on the pointed device. The external device can be located on both sides of the pointed device, on the upper edge of the pointed device, on the lower edge of the pointed device, or on the periphery of the pointed device.

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