Pose estimation method of a tag device, spatial interaction system, and electronic device

Abstract

The application provides a posture estimation method of a tag device, a space interaction system and an electronic device. The posture estimation method of the tag device comprises the following steps: determining a tag coordinate system according to the position of the tag device, and determining an accelerometer coordinate system according to the position of an accelerometer of the tag device. The gravitational acceleration of the tag system is determined. An anchor-tag rotation matrix set is determined. A target rotation matrix is determined according to the relative orientation angle between the tag device and an anchor device. The posture estimation information of the tag device in the anchor coordinate system is obtained according to the target rotation matrix. Therefore, the posture estimation method, the space interaction system and the electronic device provided by the application can reduce the design distance of the antenna on the tag device, reduce the antenna complexity of the tag device, and thus meet the light and thin, small and compact requirements of the tag device. Meanwhile, the posture estimation accuracy of the tag device on the anchor device side can also be improved.

Description

Technical Field

[0001] This application relates to the field of indoor positioning, and more specifically, to a method for attitude estimation of a tag device, a spatial interaction system, and an electronic device. Background Technology

[0002] Ultra-wideband (UWB) technology is a wireless communication technology. In indoor positioning scenarios, both the anchor device and the tag device are equipped with at least three antennas. The anchor device and the tag device communicate wirelessly using UWB technology to achieve distance measurement between the tag device and the anchor device, and attitude estimation of the tag device on the anchor device side. However, due to the miniaturization requirements of the tag device, the spacing between the antennas in the tag device is small, resulting in severe coupling between antennas and poor reception performance, thus affecting the attitude estimation of the tag device on the anchor device side. Summary of the Invention

[0003] In view of the above problems, this application provides a method for attitude estimation of a tag device, a spatial interaction system, and an electronic device.

[0004] In a first aspect, this application provides a method for attitude estimation of a tag device. The attitude estimation method includes: determining a tag coordinate system based on the position of the tag device, and determining an accelerometer coordinate system based on the position of the accelerometer on the tag device; acquiring the real-time acceleration of the tag device, including real-time gravitational acceleration; determining the tag system gravitational acceleration based on a preset accelerometer-tag rotation matrix and the real-time acceleration, wherein the tag system gravitational acceleration is a representation of the real-time gravitational acceleration in the tag coordinate system, and the accelerometer-tag rotation matrix is ​​a rotation matrix from the accelerometer coordinate system to the tag coordinate system; and determining the tag system gravitational acceleration based on the tag system gravitational acceleration. Gravitational acceleration and the pre-set anchor point system gravitational acceleration are used to determine the anchor-beacon rotation matrix set. The anchor-beacon rotation matrix set is a collection of rotation matrices from the tag coordinate system to the pre-set anchor point coordinate system. The anchor point coordinate system is determined based on the position of the pre-set anchor point device. The anchor point system gravitational acceleration is the representation of real-time gravitational acceleration in the anchor point coordinate system. The target rotation matrix is ​​determined based on the relative azimuth angle between the tag device and the anchor point device. The target rotation matrix is ​​one of the rotation matrices in the anchor-beacon rotation matrix set. Based on the target rotation matrix, the attitude estimation information of the tag device in the anchor point coordinate system is obtained.

[0005] In one implementation, the attitude estimation method further includes: determining the real-time acceleration of the anchor system based on the anchor-tag rotation matrix obtained at the previous moment and the real-time acceleration of the tag device, wherein the real-time acceleration of the anchor system is a representation of the real-time acceleration in the anchor coordinate system; filtering the real-time acceleration of the anchor system to obtain the gravitational acceleration of the anchor system, wherein the gravitational acceleration of the anchor system is a representation of the gravitational acceleration of the tag device in the anchor coordinate system; and determining the gravitational acceleration of the tag system based on the anchor-tag rotation matrix and the tag rotation matrix obtained at the previous moment, and based on the gravitational acceleration of the anchor system.

[0006] In one implementation, the relative azimuth angle includes the anchor system horizontal angle, the anchor system vertical angle, and the tag system azimuth angle. The attitude estimation method further includes: determining the anchor-target direction vector based on the anchor system horizontal angle and the anchor system vertical angle, where the anchor system horizontal angle is the horizontal azimuth angle of the tag device relative to the anchor device in the anchor coordinate system, the anchor system vertical angle is the vertical azimuth angle of the tag device relative to the anchor device in the anchor coordinate system, and the anchor-target direction vector is the representation of the unit vector pointing from the anchor device to the tag device in the anchor coordinate system; and determining the target rotation matrix based on the anchor-target rotation matrix set, the anchor-target direction vector, and the tag system azimuth angle.

[0007] In one implementation, the attitude estimation method further includes: determining the real-time gravitational acceleration based on the anchor-tag rotation matrix and the gravitational acceleration of the anchor system obtained at the previous moment; and determining the tag system gravitational acceleration based on the tag-tag rotation matrix and the real-time gravitational acceleration.

[0008] In one implementation, the attitude estimation method further includes: determining a minimum rotation matrix based on the gravitational acceleration of the anchor system and the gravitational acceleration of the tag system, wherein the minimum rotation matrix is ​​the rotation matrix that makes the gravitational acceleration of the anchor system rotate to the gravitational acceleration of the tag system with the smallest rotation angle; and determining an anchor-tag rotation matrix set based on the minimum rotation matrix and a preset rotation matrix around an axis, wherein the rotation matrix around an axis is the rotation matrix corresponding to the gravitational acceleration of the tag system as the rotation axis.

[0009] In one implementation, the attitude estimation method further includes: determining the anchor-to-tag direction vector based on the anchor-to-tag rotation matrix set and the anchor-to-tag direction vector, wherein the anchor-to-tag direction vector is the representation of the unit vector pointing from the tag device to the anchor device in the tag coordinate system; obtaining the coordinate value of the anchor-to-tag direction vector on the target coordinate axis, wherein the target coordinate axis is the coordinate axis corresponding to the azimuth angle of the tag system; and determining the target rotation matrix based on the coordinate value and the azimuth angle of the tag system.

[0010] In one implementation, the attitude estimation method further includes: determining a cost function for the coordinate values ​​and the azimuth angle of the tag system; solving the cost function to obtain the optimal solution for the coordinate values, so as to determine the target rotation matrix.

[0011] In one implementation, the anchor point device has at least three antennas, and the anchor point coordinate system is determined based on the relative positions of the three antennas of the anchor point device. The tag device has two antennas, and the tag coordinate system is determined based on the relative positions of the two antennas of the tag device.

[0012] In a second aspect, this application provides a spatial interaction system, including a tag device and an anchor point device, wherein the tag device and / or the anchor point device are used to perform the attitude estimation method in the first aspect.

[0013] Thirdly, this application provides an electronic device, which is a tag device or anchor device in the spatial interaction system of the second aspect.

[0014] Therefore, the attitude estimation method, spatial interaction system, and electronic device provided in this application can reduce the design spacing of antennas on the tag device and lower the antenna complexity, thereby meeting the requirements for thinner and smaller tag devices. Simultaneously, even when the tag device has only two antennas, by acquiring the acceleration on the tag device and determining the rotation matrix set from the tag coordinate system to the anchor coordinate system based on the direction of gravitational acceleration in the anchor coordinate system, and then determining the target rotation matrix from the tag coordinate system to the anchor coordinate system based on the azimuth angle between the tag device and the anchor device, the attitude estimation of the tag device in the anchor coordinate system is completed, improving the attitude estimation accuracy of the tag device on the anchor device side. Furthermore, the attitude estimation method for the tag device provided in this application has low algorithm complexity, can be applied to various electronic devices, and has strong compatibility. Attached Figure Description

[0015] Figure 1 A schematic diagram of the spatial interaction system provided in this application.

[0016] Figure 2 A schematic diagram of the anchor point coordinate system provided in this application.

[0017] Figure 3 A schematic diagram of the label coordinate system provided in this application.

[0018] Figure 4 A schematic diagram of the attitude estimation method provided in this application.

[0019] Figure 5 Another schematic diagram of the attitude estimation method provided in this application.

[0020] Figure 6 Another schematic diagram of the attitude estimation method provided in this application.

[0021] Figure 7 Another schematic diagram of the attitude estimation method provided in this application.

[0022] Figure 8 Another schematic diagram of the attitude estimation method provided in this application.

[0023] Figure 9 Another schematic diagram of the attitude estimation method provided in this application. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly described below with reference to the accompanying drawings.

[0025] It is understood that the connection relationships described in this application refer to direct or indirect connections. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. For example, A can be directly connected to C, and C can be directly connected to B, thus achieving a connection between A and B through C. It is also understood that the "A connects to B" described in this application can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0026] In the description of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0027] In the description of this application, the words "first," "second," etc., are used only to distinguish different objects and do not limit the quantity or order of execution, nor do they imply that they must be different. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0028] Please see Figure 1 , Figure 1 A schematic diagram of the spatial interaction system 1 provided in this application. The spatial interaction system 1 includes a tag device 11 and an anchor point device 12.

[0029] Anchor point device 12 is equipped with at least three antennas. The relative positions of the at least three antennas determine the anchor point coordinate system A. System A is a coordinate system with anchor point device 12 as the reference and origin. Here, we will illustrate this using an example where anchor point device 12 has three antennas. For example, as... Figure 2As shown, system A consists of an X-axis, a Y-axis, and a Z-axis. The three antennas are antenna A, antenna B, and antenna C. The line connecting antenna A and antenna B forms the X-axis of system A, and the line connecting antenna A and antenna C forms the Y-axis. The Z-axis of system A can be determined based on the established X and Y axes and the right-hand rule. Specifically, the Z-axis of system A is perpendicular to the plane defined by the X and Y axes. Therefore, the relative positions of antennas A, B, and C can determine the X, Y, and Z axes of system A, thus defining system A. It should be understood that the method for determining system A based on the relative positions of the three antennas is merely illustrative, and this application does not limit the method for determining system A based on the relative positions of at least three antennas.

[0030] The tag device 11 is equipped with at least two antennas. The relative positional relationship between the at least two antennas determines the tag coordinate system T. The T system is a coordinate system with the tag device 11 as the reference and origin. Here, we will illustrate this using an example where the tag device 11 has two antennas. For example, as... Figure 3 As shown, the T-system consists of an X-axis, a Y-axis, and a Z-axis, with antennas D and E. The line connecting antennas D and E forms the X-axis of the T-system. The direction perpendicular to the surface of the tag device 11 forms the Y-axis of the T-system, and the direction directly forward that the tag device 11 points forms the Z-axis of the T-system. Therefore, the relative positional relationship between antennas D and E determines the X-axis of the T-system. The Y-axis and Z-axis of the T-system can then be determined based on the attitude and orientation of the tag device 11. Thus, the T-system is ultimately determined. It is understood that the method of determining the T-system based on the relative positional relationship between two antennas is merely illustrative, and this application does not limit the method of determining the T-system based on the relative positional relationship between at least two antennas.

[0031] Anchor device 12 and tag device 11 communicate wirelessly via ultra-wideband (UWB) technology to obtain the relative position of tag device 11 with respect to anchor device 12, thereby achieving tag device 11 positioning. Specifically, anchor device 12 can transmit an UWB pulse signal to tag device 11. The UWB pulse signal includes its transmission timestamp information. After receiving the UWB pulse signal, tag device 11 calculates the time difference between the time the UWB pulse signal was transmitted by anchor device 12 and the time the UWB pulse signal was received by tag device 11, based on the transmission timestamp information and the reception timestamp information. Since the UWB pulse signal is essentially an electromagnetic wave signal, its propagation speed in the medium is approximately equal to the speed of light. Therefore, anchor device 12 or tag device 11 can calculate the distance between anchor device 12 and tag device 11 based on the time difference between the time the UWB pulse signal was transmitted by anchor device 12 and the time the UWB pulse signal was received by tag device 11 and the speed of light. That is, tag device 11 is positioned using the Time of Arrival (TOA) positioning method.

[0032] Furthermore, the tag device 11 can transmit ultra-wideband pulse signals to the anchor device 12. Since the ultra-wideband pulse signals arrive at different antennas on the anchor device 12 at different times, there is a phase difference between the received ultra-wideband pulse signals at different antennas on the anchor device 12. The anchor device 12 can calculate the distance between itself and the tag device 11 based on the phase difference between the received ultra-wideband pulse signals at different antennas. That is, the tag device 11 is located using the Phase Difference of Arrival (PDOA) positioning method.

[0033] In some embodiments, the anchor device 12 can be an electronic device such as a UWB base station, smart speaker, smart TV, air purifier, humidifier, smart lamp, desktop computer, router, smart socket, water dispenser, refrigerator, smart switch, smart door lock, customer premise equipment (CPE), TV set-top box, tablet computer, mobile phone, etc.

[0034] In some embodiments, the tag device 11 may be an electronic device such as an electronic tag, a laptop computer, a remote control, or an embedded terminal device.

[0035] In some embodiments, the tag device 11 and the anchor device 12 in the spatial interaction system 1 can be interchanged. That is, any electronic device in the spatial interaction system 1 can be a tag device 11, an anchor device 12, or both. This application does not limit the specific device type of the electronic device in the spatial interaction system 1.

[0036] In some embodiments, the number of tag devices 11 and anchor devices 12 in the spatial interaction system 1 may be greater than one. The relative positions and movement states of the tag devices 11 and anchor devices 12 can also be flexibly set according to actual needs. This application does not impose any limitations on the number, placement, or movement states of the tag devices 11 and anchor devices 12.

[0037] In some embodiments, the tag device 11 is equipped with an accelerometer. An acceleration coordinate system B can be determined based on the position of the acceleration. The B system is a coordinate system with the accelerometer as the reference and origin. The accelerometer can measure the real-time acceleration of the tag device 11. The real-time acceleration of the tag device 11 measured by the accelerometer is represented in the B system.

[0038] In addition to locating the tag device 11, the spatial interaction system 1 can also estimate the attitude of the tag device 11 on the anchor device 12 side. Thus, the anchor device 12 and / or the tag device 11 can acquire not only relative position information such as the relative distance and azimuth angle between the tag device 11 and the anchor device 12, but also the pointing orientation information and motion trajectory information of the tag device 11. In various application scenarios, this can significantly improve the interactive experience between the tag device 11 and the anchor device 12. For example, in a remote control application scenario based on UWB technology, the anchor device 12 is a UWB receiver set on a television, and the tag device 11 is a remote control for controlling the television. Based on the attitude estimation of the tag device 11 on the anchor device 12 side, the pointing orientation of the remote control can be obtained, thereby accurately calculating the specific coordinates of the remote control's pointing orientation mapped onto the television screen. For example, in the context of augmented reality (AR) applications based on UWB technology, the anchor device 12 is a fixed UWB base station, and the tag device 11 is AR glasses. The AR glasses use eye-tracking technology to obtain the user's gaze direction, and then the anchor device 12 can render the corresponding virtual scene and objects or perform corresponding operations based on the user's gaze direction.

[0039] To achieve attitude estimation of the tag device 11 on the anchor device 12 side, it is necessary to obtain the horizontal and vertical azimuth angles of the tag device 11 in the A-frame and the horizontal and vertical azimuth angles of the anchor device 12 in the T-frame, and then obtain the attitude angles of the tag device 11 on the anchor device 12 side to achieve attitude estimation of the tag device 11 on the anchor device 12 side. However, due to the need for miniaturization and portability of the tag device 11, the antenna spacing on the tag device 11 needs to be designed to be small, resulting in large coupling between antennas and poor reception performance, thus affecting the attitude estimation of the tag device 11 on the anchor device 12 side. In addition, in application scenarios where only two antennas are set on the tag device 11, the tag device 11 cannot simultaneously obtain the horizontal and vertical azimuth angles of the anchor device 12 in the T-frame, resulting in low attitude estimation accuracy of the tag device 11 on the anchor device 12 side.

[0040] Therefore, this application provides an attitude estimation method that can meet the requirements of miniaturization and portability of the tag device 11, and at the same time improve the attitude estimation accuracy of the tag device 11 on the anchor point device 12 side.

[0041] Specifically, please refer to Figure 4 , Figure 4 This is a schematic diagram of the attitude estimation method provided in this application. The attitude estimation method is applied to the space interaction system 1. Specifically, the attitude estimation method can be executed by the anchor point device 12 and / or the tag device 11, or by other electronic devices in the space interaction system 1. This application does not limit the subject executing the attitude estimation method. The attitude estimation method specifically includes the following steps.

[0042] Step S41: Determine the tag coordinate system based on the position of the tag device 11, and determine the accelerometer coordinate system based on the position of the accelerometer of the tag device 11.

[0043] Specifically, the tag coordinate system (T-system) is determined based on the position of the tag device 11, that is, a coordinate system established with the tag device 11 as the origin. The accelerometer coordinate system (B-system) is determined based on the position of the accelerometer on the tag device 11, that is, a coordinate system established with the acceleration as the origin. The coordinate axes directions and settings in the T-system and B-system are described in the previous text and will not be repeated here.

[0044] When tag device 11 executes step S41, electronic components such as the controller and processor in tag device 11 can directly establish a T-system based on the position of tag device 11 and a B-system based on the position of the accelerometer. When anchor device 12 and / or other electronic devices in space interaction system 1 execute step S41, they can determine the T-system and B-system through tag device 11 and obtain relevant information about the T-system and B-system based on the communication connection with tag device 11.

[0045] Step S42: Obtain the real-time acceleration of the tag device 11.

[0046] The real-time acceleration of tag device 11 is represented in the B-frame. When tag device 11 executes step S41, it can directly measure the real-time acceleration of tag device 11 in the B-frame using an accelerometer. When anchor device 12 and / or other electronic devices in the space interaction system 1 execute step S41, they can obtain the real-time acceleration of tag device 11 from tag device 11 based on the communication connection with tag device 11.

[0047] Step S43: Determine the gravitational acceleration of the label system based on the preset label rotation matrix and real-time acceleration.

[0048] The rotation matrix indicates the coordinate transformation relationship between two coordinate systems. Based on the rotation matrix, the representation of the same vector in one coordinate system can be transformed to its representation in another. The preset accelerometer-scaling rotation matrix is ​​the rotation matrix from the B-frame to the T-frame. Since the accelerometer is located on the terminal device, there is a preset coordinate transformation relationship between the T-frame established based on the terminal device's position and the B-frame established based on the accelerometer's position. Based on this preset coordinate transformation relationship, the preset accelerometer-scaling rotation matrix can be obtained.

[0049] In some embodiments, multiplying the rotation matrix by the matrix form of the vector to be transformed yields the matrix form of the transformed vector. For example, the rotation matrix... This represents the coordinate transformation relationship from frame B to frame T. The vector to be transformed is 'a', where 'a' represents the coordinates in frame B. Then the transformed vector is 'b', where b = ... *a. b is essentially the same vector as a, while b is the representation of that vector in the T system.

[0050] In some embodiments, real-time acceleration may include the self-motion acceleration of the tag device 11 and real-time gravitational acceleration. Even when the tag device 11 is stationary relative to the ground, its real-time acceleration still includes real-time gravitational acceleration. Therefore, real-time gravitational acceleration can be obtained from the real-time acceleration of the tag device 11. For example, the real-time gravitational acceleration can be extracted from the real-time acceleration by performing separation, filtering, or other processing on the real-time acceleration of the tag device 11. Since real-time gravitational acceleration is represented in the B-frame, the coordinate system representing real-time gravitational acceleration can be transformed from the B-frame to the T-frame using the tag-scaling rotation matrix, thereby obtaining the tag-system gravitational acceleration, i.e., the representation of real-time gravitational acceleration in the T-frame, to achieve the determination of the tag-system gravitational acceleration based on the preset tag-scaling rotation matrix and real-time acceleration.

[0051] Step S44: Determine the anchor-tag rotation matrix set based on the gravitational acceleration of the tag system and the preset gravitational acceleration of the anchor point system.

[0052] The gravitational acceleration of the anchor point system is the representation of gravitational acceleration in the A-frame. The gravitational acceleration of the anchor point system can be determined by the anchor point device 12. Since the anchor point device 12 is typically a fixed, stationary device, the anchor point coordinate system determined based on the position of the anchor point device 12 is also typically a coordinate system that is fixed and stationary relative to the Earth. Furthermore, since the value of gravitational acceleration is constant and its direction is always vertically downward, the representation of gravitational acceleration in the A-frame is stable, fixed, and unchanging.

[0053] The representation of gravitational acceleration in different coordinate systems can be obtained by converting the rotation matrix between the different coordinate systems. Conversely, the rotation matrix between different coordinate systems can also be obtained by converting the representation of gravitational acceleration in different coordinate systems. Therefore, based on the gravitational acceleration of the label system and the gravitational acceleration of the preset anchor point system, the rotation matrix between the T system and the A system can be obtained, that is, the anchor-label rotation matrix. It can be understood that for the same vector, its representation is different in different coordinate systems. Since the rotation angle between these different coordinate systems may not be unique, the rotation matrix between these different coordinate systems may also not be unique. That is, based on the gravitational acceleration of the label system and the gravitational acceleration of the preset anchor point system, we can essentially obtain the set of rotation matrices between the T system and the A system, that is, the anchor-label rotation matrix set composed of multiple anchor-label rotation matrices. The anchor-label rotation matrix set is the collection of rotation matrices from the label coordinate system to the preset anchor point coordinate system.

[0054] Step S45: Determine the target rotation matrix based on the relative azimuth angle between the tag device 11 and the anchor point device 12.

[0055] After determining the anchor-beacon rotation matrix set, one of the anchor-beacon rotation matrices in the set can be selected as the target rotation matrix based on the relative azimuth angle between the tag device 11 and the anchor point device 12. It can be understood that the target rotation matrix corresponds both to the rotation angle relationship shown by the relative azimuth angle between the tag device 11 and the anchor point device 12, and to the rotation angle relationship between the gravitational acceleration of the tag system and the gravitational acceleration of the anchor point system. Therefore, the target rotation matrix can better characterize the attitude estimation information of the tag device 11 in the anchor point coordinate system.

[0056] Step S46: Based on the target rotation matrix, obtain the attitude estimation information of the tag device 11 in the anchor point coordinate system.

[0057] The attitude estimation information may include pitch angle, yaw angle, roll angle, etc. The attitude estimation information can characterize the position and attitude angles of the tag device 11 in the anchor coordinate system, thus characterizing the motion of the tag device 11. Since the target rotation matrix can characterize the rotational relationship between the tag coordinate system and the anchor coordinate system, it can also characterize the position and attitude angles of the tag device 11 in the anchor coordinate system. In other words, based on the target rotation matrix, the attitude estimation information of the tag device 11 in the anchor coordinate system can be obtained.

[0058] Therefore, the attitude estimation method, spatial interaction system 1, and electronic device provided in this application can reduce the design spacing of antennas on the tag device 11 and reduce the antenna complexity of the tag device 11, thereby meeting the requirements for the tag device 11 to be thinner and smaller. At the same time, even when the tag device 11 has only two antennas, by obtaining the acceleration on the tag device 11 and according to the direction of gravitational acceleration in the anchor coordinate system, the rotation matrix set from the tag coordinate system to the anchor coordinate system can be obtained. Based on the azimuth angle between the tag device 11 and the anchor device 12, the target rotation matrix from the tag coordinate system to the anchor coordinate system can be determined to complete the attitude estimation of the tag device 11 in the anchor coordinate system, thereby improving the attitude estimation accuracy of the tag device 11 on the anchor device 12 side.

[0059] Please see Figure 5 , Figure 5 Another schematic diagram illustrating the attitude estimation method provided in this application. Specifically, Figure 4 Step S43 in the attitude estimation method may specifically include the following steps.

[0060] Step S431: Determine the real-time acceleration of the anchor system based on the anchor-anchor rotation matrix obtained in the previous moment and the real-time acceleration of the tag device 11.

[0061] The real-time acceleration of the anchor point system is the representation of real-time acceleration in the anchor point coordinate system. After the tag device 11, anchor device 12, and / or other electronic devices in the space interaction system 1 acquire the real-time acceleration of the tag device 11, they can convert the representation of the real-time acceleration of the tag device 11 from the acceleration coordinate system B to the anchor point coordinate system A. Specifically, the representation of the same vector in different coordinate systems can be obtained by conversion using a rotation matrix between the different coordinate systems. Therefore, the real-time acceleration of the tag device 11 can be converted from the representation in the acceleration coordinate system B to the representation in the anchor point coordinate system A according to the tag-anchor rotation matrix.

[0062] The plus-anchor rotation matrix can be obtained by... Figure 4 The target rotation matrix obtained in steps S41-S45 is converted to obtain the target rotation matrix. Specifically, the target rotation matrix indicates the transformation relationship between the label coordinate system T and the anchor point coordinate system A, and the preset label-addition rotation matrix indicates the transformation relationship between the B system and the T system. Therefore, multiplying the label-addition rotation matrix by the target rotation matrix yields the label-anchor rotation matrix. Since... Figure 4 Steps S41-S45 in the process continue to be executed. Therefore, the target rotation matrix obtained in the previous moment can be used for conversion to estimate the anchor-addition rotation matrix in the previous moment.

[0063] Step S432: Filter the real-time acceleration of the anchor point system to obtain the gravitational acceleration of the anchor point system.

[0064] The gravitational acceleration of the anchor point system is the representation of the gravitational acceleration of the tag device 11 in the anchor point coordinate system. Filtering the real-time acceleration of the anchor point system can remove the components other than gravitational acceleration, thus retaining the gravitational acceleration of the anchor point system. Specifically, the real-time acceleration of the anchor point system includes the movement velocity of the tag device 11 itself, gravitational acceleration, noise, etc. The movement velocity and / or noise of the tag device 11 itself are represented by higher frequency components in the frequency spectrum, while the gravitational acceleration is represented by lower frequency components. Filtering the real-time acceleration of the anchor point system, for example, with a second-order Butterworth low-pass filter, can filter out the gravitational acceleration of the anchor point system, thereby removing the movement velocity and other components and / or noise of the tag device 11 itself. In addition, filtering based on the real-time acceleration of the anchor point system benefits from the constant and stable characteristics of the anchor point coordinate system A, allowing for stable and constant filtering of the real-time acceleration of the anchor point system, which can improve the filtering accuracy and stability.

[0065] Step S433: Based on the anchor-tag rotation matrix and the tag-label rotation matrix obtained in the previous moment, determine the tag system's gravitational acceleration based on the anchor system's gravitational acceleration.

[0066] The tag-system gravitational acceleration is the representation of the gravitational acceleration of the tag device 11 in the tag coordinate system T. The anchor-system gravitational acceleration can be converted into a representation in the accelerometer coordinate system B using the anchor-tag rotation matrix obtained at the previous moment. That is, the real-time gravitational acceleration is determined based on the anchor-tag rotation matrix and the anchor-system gravitational acceleration obtained at the previous moment. The real-time gravitational acceleration is the representation of the gravitational acceleration of the tag device 11 in the accelerometer coordinate system B.

[0067] The real-time gravitational acceleration is then further converted into a representation in the label coordinate system T through a preset addition-label rotation matrix, thus obtaining the label system gravitational acceleration.

[0068] Please see Figure 6 , Figure 6 Another schematic diagram illustrating the attitude estimation method provided in this application. Specifically, Figure 4 Step S45 in the attitude estimation method may specifically include the following steps.

[0069] Step S451: Determine the anchor-beacon direction vector based on the horizontal angle and vertical angle of the anchor system.

[0070] The relative azimuth angle between the tag device 11 and the anchor point device 12 includes the anchor point system horizontal angle, the anchor point system vertical angle, and the tag system azimuth angle. The anchor point system horizontal angle is the horizontal azimuth angle of the tag device 11 relative to the anchor point device 12 in the anchor point coordinate system, and the anchor point system vertical angle is the vertical azimuth angle of the tag device 11 relative to the anchor point device 12 in the anchor point coordinate system. The anchor-tag direction vector is the representation of the unit vector pointing from the anchor point device 12 to the tag device 11 in the anchor point coordinate system.

[0071] Among them, the anchor-beacon direction vector It can be represented in matrix form as follows.

[0072]

[0073] in, The horizontal azimuth angle of the tag device 11 relative to the anchor point device 12 in the anchor point coordinate system. The vertical azimuth angle of the tag device 11 relative to the anchor point device 12 in the anchor point coordinate system.

[0074] Step S452: Determine the target rotation matrix based on the anchor-marker rotation matrix set, the anchor-marker direction vector, and the azimuth angle of the label system.

[0075] The anchor-tag rotation matrix set includes multiple rotation matrices from the tag coordinate system T to the preset anchor point coordinate system A, with the target rotation matrix being one of them. The tag system azimuth angle is one of the azimuth angles of the anchor point device 12 relative to the tag device 11 in the tag coordinate system T, such as a horizontal angle or a vertical angle. Here, the example of a horizontal angle is used, but this application does not limit the type of tag system azimuth angle.

[0076] In some embodiments, the tag device 11 is provided with two antennas. The tag device 11 can measure one of the azimuth angles of the anchor device 12 relative to the tag device 11 in the tag coordinate system T based on the phase difference between the signals transmitted by the anchor device 12 and the two antennas on the tag device 11. The type of tag system azimuth angle can be obtained according to the arrangement of the two antennas, and the arrangement of the two antennas can also be flexibly adjusted according to the type of tag system azimuth angle to be obtained. Compared with setting three or more antennas on the tag device 11 to obtain more types of tag system azimuth angles, in this application, the tag device 11 can obtain only one type of tag system azimuth angle and combine it with... Figure 4 The attitude estimation method of the tag device 11 can accurately estimate the attitude of the tag device 11 in the anchor point coordinate system, and the structure of the tag device 11 can also be simplified, made lighter and smaller.

[0077] Based on the anchor-beacon direction vector and the tag system azimuth angle, one of the anchor-beacon rotation matrix sets can be determined that matches the relative position angle between the anchor point device 12 and the tag device 11 indicated by the anchor-beacon direction vector and the tag system azimuth angle. Then, based on the representation of gravitational acceleration in the anchor point coordinate system... With the acceleration due to gravity of the label system By understanding the rotational transformation relationship between the coordinates, the target rotation matrix can be obtained. That is, the target rotation matrix can represent the gravitational acceleration in the anchor point coordinate system. Converted to label-based gravitational acceleration It can also indicate the relative position angle between the anchor point device 12 and the tag device 11, thereby better representing the attitude estimation information of the tag device 11 in the anchor point coordinate system.

[0078] Please see Figure 7 , Figure 7 Another schematic diagram illustrating the attitude estimation method provided in this application. Specifically, Figure 6 Step S452 in the attitude estimation method may specifically include the following steps.

[0079] Step S71: Determine the minimum rotation matrix based on the gravitational acceleration of the anchor point system and the gravitational acceleration of the tag system.

[0080] Wherein, the minimum rotation matrix is ​​the one that makes the gravitational acceleration of the anchor point system... Rotate to the label system's gravitational acceleration Furthermore, it is the rotation matrix with the smallest rotation angle. Specifically, taking the Y-axis of the coordinate system A as vertically downward as an example, the preset gravitational acceleration is represented in the A-system. It can be represented in matrix form as follows.

[0081]

[0082] Based on the anchor-mark rotation matrix, it is possible to... With the acceleration due to gravity of the label system They can be mutually converted, thus allowing the construction of a minimum rotation vector v, such that... Rotate by the minimum angle to... Overlap. Where v = At this point, the matrix form corresponding to v is the minimum rotation matrix.

[0083] Step S72: Determine the anchor-beacon rotation matrix set based on the minimum rotation matrix and the preset rotation matrix around the axis.

[0084] Wherein, the rotation matrix around the axis is the acceleration due to gravity of the label system. Let be the rotation matrix corresponding to the rotation axis. A vector rotating along the rotation axis retains its representation unchanged; therefore, multiplying the rotation matrix about the axis by the minimum rotation matrix on the right is equivalent to... After rotating to the minimum angle, continue along... The rotation matrix corresponding to the rotation along the rotation axis in the direction is also known as the anchor-marker rotation matrix. Wherein, along... The anchor-mark rotation matrix varies depending on the angle of rotation of the rotation axis. Therefore, the anchor-mark rotation matrix corresponding to all rotation angles forms the anchor-mark rotation matrix set.

[0085] Please see Figure 8 , Figure 8 Another schematic diagram of the attitude estimation method provided in this application. Specifically, step S452 in the attitude estimation method shown in the figure may include the following steps.

[0086] Step S81: Determine the anchor-beacon direction vector based on the anchor-beacon rotation matrix set and the anchor-beacon direction vector.

[0087] The tag-anchor direction vector is the representation of the unit vector pointing from the tag device 11 to the anchor point device 12 in the tag coordinate system T. Since the anchor-tag direction vector is the representation of the unit vector pointing from the anchor point device 12 to the tag device 11 in the anchor point coordinate system A, the tag-anchor direction vector and the anchor-tag direction vector should be vectors with opposite directions. Furthermore, the anchor-tag direction vector can be obtained by left-multiplying the anchor-tag direction vector by one of the vectors in the anchor-tag rotation matrix set and then reversing the direction.

[0088] Step S82: Obtain the coordinate values ​​of the anchor-beacon direction vector on the target coordinate axis.

[0089] The target coordinate axis is the coordinate axis corresponding to the azimuth angle of the tag system. For example, when the azimuth angle of the tag system is horizontal, the target coordinate axis can be the X-axis of the tag coordinate system T; when the azimuth angle of the tag system is vertical, the target coordinate axis can be the Y-axis of the tag coordinate system T. The tag device 11 can calculate the coordinate value of the anchor-marker direction vector on the target coordinate axis based on the angle between the anchor-marker direction vector and the target coordinate axis.

[0090] Step S83: Determine the target rotation matrix based on the coordinate values ​​and the azimuth angle of the label system.

[0091] The coordinate values ​​and the azimuth angle of the tag system can represent the relative position angle between the anchor device 12 and the tag device 11. Therefore, based on the coordinate values ​​and the azimuth angle of the tag system, one of the anchor-tag rotation matrices in the anchor-tag rotation matrix set can be determined. The rotation direction corresponding to this matrix matches the relative position angle between the anchor device 12 and the tag device 11. This anchor-tag rotation matrix can then be used as the target rotation matrix.

[0092] Please see Figure 9 , Figure 9 Another schematic diagram of the attitude estimation method provided in this application. Specifically, step S452 in the attitude estimation method shown in the figure may include the following steps.

[0093] Step S91: Determine the cost function for the coordinate values ​​and the azimuth angle of the label system.

[0094] The cost function J can be represented as the relationship between the coordinate values ​​and the azimuth angle of the label system. Here, the representation of J is as follows.

[0095]

[0096] in, The coordinates of the anchor-beam direction vector on the target coordinate axis. For the azimuth of the label system, This refers to the coordinates of the tag-anchor direction vector on the target coordinate axis, calculated based on the tag system azimuth angle actually measured by the tag device 11. To obtain the anchor-beacon direction vector based on the anchor point system's horizontal and vertical angles actually measured by the anchor point device 12, the coordinate values ​​of the beacon-anchor direction vector on the target coordinate axis are further estimated based on the anchor-beacon direction vector and the anchor-beacon rotation matrix set.

[0097] Step S92: Solve the cost function to obtain the optimal solution for the coordinate values, and then determine the target rotation matrix.

[0098] By constructing the cost function, we can find that... and The closest anchor-mark rotation matrix is ​​one of the anchor-mark rotation matrices in the set. That is, by solving the cost function, we can obtain... The optimal solution ensures that the direction of the marker-anchor direction vector obtained from the relative position angle of the tag device 11 measured by the anchor point device 12 and the anchor-mark rotation matrix set is aligned with the direction of the marker-anchor direction vector calculated from the relative position angle of the anchor point device 12 measured by the tag device 11. At this point, The anchor-target rotation matrix corresponding to the optimal solution is the target rotation matrix.

[0099] In some embodiments, the cost function can be solved using the Gauss-Newton iteration method.

[0100] Therefore, the attitude estimation method, spatial interaction system 1, and electronic device provided in this application can reduce the design spacing of antennas on the tag device 11 and reduce the antenna complexity of the tag device 11, thereby meeting the requirements for the tag device 11 to be thinner and smaller. Simultaneously, even when the tag device 11 has only two antennas, by obtaining the acceleration on the tag device 11 and based on the direction of gravitational acceleration in the anchor point coordinate system, a set of rotation matrices from the tag coordinate system to the anchor point coordinate system can be obtained. Furthermore, based on the azimuth angle between the tag device 11 and the anchor point device 12, the target rotation matrix from the tag coordinate system to the anchor point coordinate system can be determined to complete the attitude estimation of the tag device 11 in the anchor point coordinate system, thus improving the attitude estimation accuracy of the tag device 11 on the anchor point device 12 side. In addition, the attitude estimation method provided in this application has low algorithm complexity, can be applied to various electronic devices, and has strong compatibility.

[0101] Those skilled in the art should recognize that the above embodiments are only used to illustrate this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of protection claimed in this application.

Claims

1. A method for attitude estimation of a tag device, characterized in that, The attitude estimation method includes: The tag coordinate system is determined based on the position of the tag device, and the accelerometer coordinate system is determined based on the position of the accelerometer of the tag device; The real-time acceleration of the tag device is obtained, including real-time gravitational acceleration; The tag system gravitational acceleration is determined based on the preset accelerometer-to-tag rotation matrix and the real-time acceleration. The tag system gravitational acceleration is the representation of the real-time gravitational acceleration in the tag coordinate system, and the accelerometer-to-tag rotation matrix is ​​the rotation matrix from the accelerometer coordinate system to the tag coordinate system. Based on the gravitational acceleration of the tag system and the preset gravitational acceleration of the anchor point system, an anchor-tag rotation matrix set is determined. The anchor-tag rotation matrix set is a set of rotation matrices from the tag coordinate system to the preset anchor point coordinate system. The anchor point coordinate system is determined according to the position of the preset anchor point device. The gravitational acceleration of the anchor point system is the representation of the real-time gravitational acceleration in the anchor point coordinate system. The target rotation matrix is ​​determined based on the relative azimuth angle between the tag device and the anchor point device, and the target rotation matrix is ​​one of the rotation matrices in the anchor-tag rotation matrix set; Based on the target rotation matrix, the attitude estimation information of the tag device in the anchor point coordinate system is obtained.

2. The attitude estimation method as described in claim 1, characterized in that, The attitude estimation method further includes: Based on the anchor-tag rotation matrix obtained at the previous moment and the real-time acceleration of the tag device, the real-time acceleration of the anchor system is determined, and the real-time acceleration of the anchor system is the representation of the real-time acceleration in the anchor coordinate system. The real-time acceleration of the anchor point system is filtered to obtain the gravitational acceleration of the anchor point system, which is the representation of the gravitational acceleration of the tag device in the anchor point coordinate system. Based on the anchor-tag rotation matrix and the tag rotation matrix obtained at the previous moment, the gravitational acceleration of the tag system is determined according to the gravitational acceleration of the anchor system.

3. The attitude estimation method as described in claim 1, characterized in that, The relative azimuth angle includes the anchor system horizontal angle, the anchor system vertical angle, and the tag system azimuth angle. The attitude estimation method further includes: Based on the horizontal angle and the vertical angle of the anchor point system, the anchor-beacon direction vector is determined. The horizontal angle of the anchor point system is the horizontal azimuth angle of the tag device relative to the anchor point device in the anchor point coordinate system. The vertical angle of the anchor point system is the vertical azimuth angle of the tag device relative to the anchor point device in the anchor point coordinate system. The anchor-beacon direction vector is the representation of the unit vector pointing from the anchor point device to the tag device in the anchor point coordinate system. The target rotation matrix is ​​determined based on the anchor-mark rotation matrix set, the anchor-mark direction vector, and the label system azimuth angle.

4. The attitude estimation method as described in claim 2, characterized in that, The attitude estimation method further includes: The real-time gravitational acceleration is determined based on the anchor-anchor rotation matrix obtained in the previous moment and the gravitational acceleration of the anchor point system. The gravitational acceleration of the tag system is determined based on the tag rotation matrix and the real-time gravitational acceleration.

5. The attitude estimation method as described in claim 3, characterized in that, The attitude estimation method further includes: Based on the gravitational acceleration of the anchor point system and the gravitational acceleration of the tag system, a minimum rotation matrix is ​​determined. The minimum rotation matrix is ​​the rotation matrix that minimizes the rotation angle of the gravitational acceleration of the anchor point system to the gravitational acceleration of the tag system. Based on the minimum rotation matrix and the preset rotation matrix around the axis, the anchor-tag rotation matrix set is determined, wherein the rotation matrix around the axis is the rotation matrix corresponding to the gravitational acceleration of the tag system as the rotation axis.

6. The attitude estimation method as described in claim 3, characterized in that, The attitude estimation method further includes: Based on the anchor-mark rotation matrix set and the anchor-mark direction vector, the mark-anchor direction vector is determined. The mark-anchor direction vector is a representation of the unit vector pointing from the label device to the anchor point device in the label coordinate system. Obtain the coordinate value of the tag-anchor direction vector on the target coordinate axis, where the target coordinate axis is the coordinate axis corresponding to the azimuth angle of the tag system; The target rotation matrix is ​​determined based on the coordinate values ​​and the azimuth angle of the label system.

7. The attitude estimation method as described in claim 6, characterized in that, The attitude estimation method further includes: Determine the cost function for the coordinate values ​​and the azimuth angle of the tag system; Solve the cost function to obtain the optimal solution for the coordinate values, and then determine the target rotation matrix.

8. The attitude estimation method as described in any one of claims 1 to 7, characterized in that, The anchor point device is equipped with at least three antennas, and the anchor point coordinate system is determined based on the relative positions of the three antennas of the anchor point device. The tag device is equipped with two antennas, and the tag coordinate system is determined based on the relative positions of the two antennas of the tag device.

9. A spatial interaction system, characterized in that, It includes a tag device and an anchor device, wherein the tag device and / or the anchor device are used to perform the attitude estimation method as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, The electronic device is the tag device or the anchor point device in the spatial interaction system as described in claim 9.

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