Radar rotation angle adjusting method and system based on scene interaction

Abstract

The invention relates to the technical field of radar control, and relates to a radar rotation angle adjusting method and system based on scene interaction. Obtaining the three-dimensional coordinates of four vertexes of the projection area of the projector according to the height, the projection ratio and the aspect ratio of the projector to the projection area, and obtaining the three-dimensional coordinates of the radar; determining an initial rotation angle of the radar; the heart rate of a patient and electromyographic signals of legs are collected, and a compensation angle is calculated according to the heart rate and the electromyographic signals; and determining the sum of the compensation angle and the initial rotation angle as the rotation angle of the radar. The rotation angle of the radar is adjusted according to the physiological signal of the patient, and the problem that the radar cannot accurately capture the key action track of the patient due to body imbalance of the patient is solved.

Description

Technical Field

[0001] The present invention generally relates to the field of radar control technology. More specifically, the present invention relates to a radar rotation angle adjustment method and system based on scenario interaction. Background Art

[0002] Rehabilitation training methods based on motion capture technology have gradually become an important tool for patient rehabilitation, especially in improving motor function and emotional experience. This method generally relies on real-time capture and analysis of the patient's body movement data, by accurately measuring the patient's movements, including displacement, speed, angle, and other movement characteristics. This data is then used to generate interactive virtual scenes, and the patient's movements can directly affect game characters, environmental changes, or other interactive feedback elements in the virtual world. This situational interactive therapy is particularly suitable for children's rehabilitation. It emphasizes the purposeful introduction of vivid and specific scenes with specific emotional colors and images as the main body to stimulate children's participation interest and emotional experience, achieve effective interaction and timely feedback, and obtain patients' movement data with high precision and high density.

[0003] In a rehabilitation training system based on situational interaction, radar (such as millimeter-wave radar, optical radar, or other motion capture radar) captures the patient's (particularly pediatric) body movements in real time and contactlessly. This captured motion data is used to drive interactive elements in the virtual scene (such as controlling game characters and triggering scene feedback). Mechanical scanning radars rotate through a mechanical mechanism, covering a specific angle range. This reciprocating rotation allows the radar to gradually scan a larger area or multiple directions. This enables the radar to gradually complete detection of the surrounding environment and acquire data from different angles.

[0004] To ensure the accuracy of human motion data detected by radar, existing technologies typically minimize the radar's rotation angle (scanning range). A smaller scanning range allows the radar beam to cover a limited area more densely per unit time, resulting in a longer dwell time in each direction and improving the signal-to-noise ratio (SNR) and position resolution of single-point measurements.

[0005] However, the behavioral patterns of patients (especially children) during scenario-based interactive training are highly unpredictable and vary from person to person. When a physician-designed scenario successfully sparks a child's interest or a specific emotional state (such as excitement, curiosity, or the urge to imitate), the child may exhibit large movements. In this case, if the radar's rotation angle is too small, the patient's body parts (or entire body) may quickly move out of the radar's limited detection area, making it impossible to continuously and completely capture the patient's key movements. This can lead to interrupted, delayed, or distorted interactive feedback in the virtual scene. Summary of the Invention

[0006] In order to solve the technical problem that the rotation angle of the above-mentioned radar is too small and it is impossible to continuously and completely capture the patient's key movement trajectory, the present invention proposes a radar rotation angle method and system based on scenario interaction.

[0007] In a first aspect, a radar rotation angle adjustment method based on scenario interaction includes: in a world coordinate system with the center of gravity of the projection area as the origin, obtaining the three-dimensional coordinates of the four vertices of the projection area of ​​the projector according to the height of the projector from the projection area, the projection ratio and the aspect ratio, and obtaining the three-dimensional coordinates of the radar, wherein the projection area is a rectangular area; determining the initial rotation angle of the radar; collecting the patient's heart rate and electromyographic signals of the legs, and calculating the compensation angle according to the heart rate and the electromyographic signals, wherein the compensation angle is proportional to the heart rate, the compensation angle is inversely proportional to the electromyographic signals, and the compensation angle is related to an initial compensation angle of a preset size; and determining the sum of the compensation angle and the initial rotation angle as the rotation angle of the radar.

[0008] Preferably, obtaining the three-dimensional coordinates of the four vertices of the projection area of ​​the projector includes: calculating the horizontal coordinate coefficients x , where the calculation formula is: ,in h is the height of the projector from the projection area, a is the projection ratio of the projector; calculate the ordinate coefficient y , where the calculation formula is ,in b is the aspect ratio of the projector; determine the three-dimensional coordinates of the four vertices of the target projection area as: (-x, y, 0), (x, -y, 0), (-x, -y, 0) and (x, y, 0).

[0009] Preferably, in response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being greater than or equal to 0, the formula for calculating the initial scanning angle of the radar is: , where (x1, y1, z1) are the three-dimensional coordinates of the radar, α is the initial scanning angle of the radar; in response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being less than 0, the formula for calculating the initial scanning angle of the radar is: .

[0010] Preferably, the formula for calculating the compensation angle is: .

[0011] in, θ is the compensation angle, θ0 is the initial compensation angle, E is the electromyographic signal, E 0 is the standard electromyographic signal of the preset size, H is the heart rate, H 0 is the standard heart rate of the preset size, exp() is the exponential function with the constant e as the base, norm () is the standard normalization function, norm () is used to Mapped to the value range (0,1).

[0012] Preferably, the initial compensation angle is 10°.

[0013] Preferably, the standard electromyographic signal is 20 μV.

[0014] Preferably, the standard heart rate is 75 bpm.

[0015] Preferably, the patient's heart rate is obtained by a sliding window mean filtering algorithm, wherein the formula for calculating the patient's heart rate is: , H is the heart rate, N is the window size, h i For the i Real-time heart rate at all times, h k is the real-time heart rate at the current moment, i and k All are positive integers.

[0016] Preferably, the patient's electromyographic signal is obtained by a sliding window mean filtering algorithm, wherein the formula for calculating the patient's heart rate is: , E is the electromyographic signal, N is the window size, e i For the i Real-time heart rate at all times, e k is the real-time heart rate at the current moment, i and k All are positive integers.

[0017] In a second aspect, a radar rotation angle adjustment system based on scenario interaction includes a processor and a memory, wherein the memory stores a computer program, and is characterized in that the processor executes the computer program to implement a radar rotation angle adjustment method based on scenario interaction as described in any one of claims 1 to 9.

[0018] The beneficial effects of the present invention are: The present invention uses the patient's (current moment) electromyographic signal and heart rate to adjust the compensation angle, thereby correcting the radar's rotation angle. The smaller the patient's electromyographic signal or the larger their heart rate, the greater the probability that the patient is unbalanced and out of the radar's scanning range, and the larger the radar rotation angle. Based on this, the present invention adjusts the radar's rotation angle based on the patient's physiological signals, avoiding the problem of the radar being unable to accurately capture the patient's key movements due to imbalance. Furthermore, when the patient is relatively balanced, the radar's rotation angle is reduced to increase the accuracy of the patient's motion data. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an illustrative and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 is a flowchart schematically illustrating the steps of a radar rotation angle adjustment method based on scenario interaction according to an embodiment of the present invention; Figure 2 is a schematic diagram of the positional relationship between a radar and a projection area according to an embodiment of the present invention; Figure 3 Schematically shows a structural block diagram of a radar rotation angle adjustment system based on scenario interaction according to this embodiment. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0021] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] Figure 1 The figure schematically shows a flowchart of the steps of a radar rotation angle adjustment method based on scenario interaction according to an embodiment of the present invention.

[0023] like Figure 1 As shown, a radar rotation angle adjustment method based on scenario interaction includes steps S1 to S4.

[0024] Step S1: Obtain the three-dimensional coordinates of the four vertices of the projection area of ​​the projector according to the height of the projector from the projection area, the projection ratio and the aspect ratio, and obtain the three-dimensional coordinates of the radar.

[0025] The projection area is a rectangular area. The three-dimensional coordinates of the four vertices of the projection area and the three-dimensional coordinates of the radar are all in a world coordinate system with the center of gravity of the projection area as the origin.

[0026] In one embodiment, obtaining the three-dimensional coordinates of the four vertices of the projection area of ​​the projector includes: calculating the abscissa coefficients x , where the calculation formula is: ,in h is the height of the projector from the projection area, a is the projection ratio of the projector; calculate the ordinate coefficient y , where the calculation formula is ,in b is the aspect ratio of the projector; determine the three-dimensional coordinates of the four vertices of the target projection area as: (-x, y, 0), (x, -y, 0), (-x, -y, 0) and (x, y, 0).

[0027] For clarification, the throw ratio refers to the ratio of projection distance to image width. The aspect ratio is the ratio between the width and height of a video image, and the aspect ratio of a projector is the ratio between the width and height of the projected image. Based on the projector's height from the projection area, the throw ratio, and the aspect ratio, the positions of the four vertices of the projection area—that is, their 3D coordinates—can be determined.

[0028] Step S2: Determine the initial rotation angle of the radar.

[0029] In one embodiment, in response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being greater than or equal to 0, the formula for calculating the initial scanning angle of the radar is: , where (x1, y1, z1) is the three-dimensional coordinate of the radar, α is the initial scanning angle of the radar.

[0030] like Figure 2 As shown, the circle is the radar and the matrix in the xy plane is the projection area. Initial scanning angle α is the angle between the first vector and the second vector, so according to the angle formula between vectors, we can deduce ,in is the first vector, which is the vertex vector with coordinates (-x, -y, 0) pointing from the radar position to the projection area, is the second vector, which is the vertex vector with coordinates (x, y, 0) pointing from the radar position to the projection area, and the first vector satisfy: , the first vector satisfy: . Then further deduce the above calculation of initial scanning angle α formula.

[0031] In another embodiment, in response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being less than 0, the initial scanning angle α is the third vector and the fourth vector The angle between the third vector is the vertex vector with coordinates (-x, y, 0) pointing from the radar position to the projection area, and the fourth vector is the vertex vector with coordinates (x, -y, 0) pointing from the radar position to the projection area. Therefore, the first vector satisfy: , the first vector satisfy: . Then further deduce and calculate the initial scanning angle α The formula is: .

[0032] It should be noted that when the patient is interacting with the situation, he or she moves in the projection area of ​​the projector, so the radar collection range needs to cover the projection area of ​​the projector.

[0033] Step S3: collecting the patient's heart rate and electromyographic signals of the legs, and calculating the compensation angle according to the heart rate and the electromyographic signals.

[0034] The compensation angle is proportional to the heart rate, inversely proportional to the electromyographic signal, and is related to an initial compensation angle of a preset size.

[0035] It's important to note that electromyography (EMG) is an electrical signal that reflects muscle activity. The electrical activity generated by muscle contraction is called an EMG signal. The strength of the EMG signal is generally proportional to the degree of muscle activity; the stronger the muscle contraction, the stronger the signal. Heart rate refers to the number of heartbeats per unit time, usually expressed in beats per minute (bpm). When emotionally excited, the sympathetic nerves become activated, typically causing the heart rate to increase. Once emotions calm, the heart rate gradually returns to normal.

[0036] In one embodiment, the formula for calculating the compensation angle is: .

[0037] in, θ is the compensation angle, θ 0 is the initial compensation angle,E is the electromyographic signal, E 0 is the standard electromyographic signal of the preset size, H is the heart rate, H 0 is the standard heart rate of the preset size, exp() is the exponential function with the constant e as the base, norm () is the standard normalization function, norm () is used to Mapped to the value range (0,1).

[0038] In one embodiment, the initial compensation angle θ 0 is 10°. Standard EMG signal E 0 is 20μV. Standard heart rate H 0 is 75bpm.

[0039] It should be noted that when a patient's heart rate is greater than the standard heart rate, it indicates that the patient is in an excited state. The higher the heart rate, the more excited the patient is, and the greater the probability that the patient's body will leave the projection area. When the patient's electromyographic signal is less than the standard electromyographic signal, it indicates that the patient's muscle activity is weak. The smaller the electromyographic signal, the weaker the patient's muscle activity, and the greater the probability that the patient's body will leave the projection area. Based on this, the compensation angle is proportional to the heart rate and inversely proportional to the electromyographic signal.

[0040] In one embodiment, the patient's heart rate is obtained by a sliding window mean filtering algorithm, wherein the formula for calculating the patient's heart rate is: , H is the heart rate, N is the window size, h i For the i Real-time heart rate at all times, h k is the real-time heart rate at the current moment, i and k are all positive integers. Similarly, the patient's electromyographic signal is obtained by the sliding window mean filtering algorithm, where the formula for calculating the patient's heart rate is: , E is the electromyographic signal, N is the window size, e i For the i Real-time heart rate at all times, e k is the real-time heart rate at the current moment, i and k In one embodiment, the window size N The value of is 5.

[0041] It should be noted that real-time heart rate and electromyography signals are often affected by noise, such as sensor errors and environmental interference. This noise can cause data fluctuations, thus affecting the calculation of the compensation angle. Sliding window mean filtering can reduce the impact of this noise and make the signal more stable. Sliding window mean filtering is a simple filtering method based on local data. It smoothes the signal by calculating the mean of the data within the window and reduces the impact of high-frequency noise. The steps for implementing sliding window mean filtering are: within a fixed-size window, the average of all data points in the window is calculated and used as the filtered output at the current moment. The window slides along the signal's time axis, repeatedly calculating a new average value each time it slides one data point. In the above embodiment, the window size N is 5, meaning that each time the heart rate or electromyography signal is calculated, the real-time data from the previous five moments is considered. A larger window size improves the smoothing effect, but also increases computational latency and data distortion. A smaller window size improves response speed but may not smooth out strong noise. Calculating the heart rate and electromyographic signal (at the current moment) using the sliding window mean filter can avoid large data errors in the real-time heart rate or real-time electromyographic signal caused by excessive noise interference.

[0042] Real-time heart rate and real-time electromyography (EMG) are physiological data collected by sensors over time. Real-time heart rate refers to the number of heartbeats per minute at a given moment, representing an instantaneous measurement of the heart rate. Real-time EMG refers to the electrical activity of muscles collected in real time at each moment.

[0043] Step S4: Determine the sum of the compensation angle and the initial rotation angle as the rotation angle of the radar.

[0044] It should be noted that compensation angle dynamically adjusts the radar's rotation angle based on physiological signals (such as the patient's heart rate and electromyography). Its primary purpose is to compensate for changes in the patient's physiological state, thereby ensuring accuracy and stability during radar scanning.

[0045] The patient's heart rate and leg EMG signals are both currently collected data, and the radar's rotation angle is also the radar's rotation angle at that moment. In other words, the patient's heart rate and leg EMG signals are collected in real time, and the radar's rotation angle is also calculated in real time. The radar's initial rotation angle only needs to be calculated once, and it doesn't change over time. The same initial rotation angle is used for calculating the radar's rotation angle at each moment.

[0046] Based on this, the present invention determines the spatial coordinates and radar position of the patient's activity area through the parameters of the projector, and calculates the initial rotation angle covering the entire projection area. On this basis, the patient's heart rate and leg electromyographic signals are monitored in real time: through the dual signal feedback of heart rate and electromyography, the trend of changes in the patient's movement amplitude is predicted, and the radar scanning range is actively expanded when the patient is emotionally excited or the muscles are relaxed (high risk of imbalance) to avoid movement loss; when the patient's condition is stable, a smaller scanning angle is maintained to ensure single-point measurement accuracy; sliding window filtering is used to improve the reliability of physiological signals and ensure that the compensation mechanism responds in a timely and anti-interference manner. The present invention can improve the continuity of motion capture and the authenticity of virtual feedback in situational interactive rehabilitation training, and is particularly suitable for pediatric patients with unpredictable behavior.

[0047] Figure 3 Schematically shows a structural block diagram of a radar rotation angle adjustment system based on scenario interaction according to this embodiment.

[0048] The present invention also provides a radar rotation angle adjustment system based on scenario interaction. Figure 2 As shown, the system includes a processor and a memory, and the memory stores computer program instructions. When the computer program instructions are executed by the processor, a radar rotation angle adjustment method based on scenario interaction according to the first aspect of the present invention is implemented.

[0049] The system also includes other components well known to those skilled in the art, such as a communication interface, and the configuration and functions of which are known in the art, so they will not be described in detail here.

[0050] In the present invention, the aforementioned memory can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, the computer-readable storage medium can be any suitable magnetic or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc., or any other medium that can be used to store the required information and can be accessed by an application, module, or both. Any such computer storage medium can be part of, accessible to, or connectable to a device. Any application or module described in the present invention can be implemented using computer-readable / executable instructions that can be stored or otherwise maintained by such a computer-readable medium.

[0051] In the description of this specification, "multiple" and "several" mean at least two, such as two, three or more, unless otherwise clearly defined.

[0052] While several embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous modifications, variations, and alternatives will occur to those skilled in the art without departing from the concept and spirit of the present invention. It should be understood that various alternatives to the embodiments of the present invention described herein may be employed in practicing the present invention.

Claims

1. A radar rotation angle adjustment method based on scenario interaction, characterized in that: include: In a world coordinate system with the center of gravity of the projection area as the origin, obtaining the three-dimensional coordinates of the four vertices of the projection area of ​​the projector according to the height of the projector from the projection area, the projection ratio, and the aspect ratio, thereby obtaining the three-dimensional coordinates of the radar, wherein the projection area is a rectangular area; Determine the initial rotation angle of the radar; collecting the patient's heart rate and electromyographic signals of the legs, and calculating a compensation angle based on the heart rate and the electromyographic signals, wherein the compensation angle is proportional to the heart rate, inversely proportional to the electromyographic signals, and related to an initial compensation angle of a preset size; The sum of the compensation angle and the initial rotation angle is determined to be the rotation angle of the radar.

2. The radar rotation angle adjustment method based on scenario interaction according to claim 1, characterized in that: Obtaining the three-dimensional coordinates of the four vertices of the projection area of ​​the projector includes: Calculate the abscissa coefficient x , where the calculation formula is: ,in h is the height of the projector from the projection area, a is the projection ratio of the projector; calculate the ordinate coefficient y , where the calculation formula is ,in b is the aspect ratio of the projector; Determine the three-dimensional coordinates of the four vertices of the target projection area as: (-x, y, 0), (x, -y, 0), (-x, -y, 0) and (x, y, 0).

3. The radar rotation angle adjustment method based on scenario interaction according to claim 2, characterized in that: In response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being greater than or equal to 0, the formula for calculating the initial scanning angle of the radar is: , where (x1, y1, z1) are the three-dimensional coordinates of the radar, α is the initial scanning angle of the radar; In response to the horizontal coordinate corresponding to the three-dimensional coordinate of the radar being less than 0, the formula for calculating the initial scanning angle of the radar is: .

4. The radar rotation angle adjustment method based on scenario interaction according to claim 1, characterized in that: The formula for calculating the compensation angle is: ； in, θ is the compensation angle, θ 0 is the initial compensation angle, E is the electromyographic signal, E 0 is the standard electromyographic signal of the preset size, H is the heart rate, H 0 is the standard heart rate of the preset size, exp() is the exponential function with the constant e as the base, norm () is the standard normalization function, norm () is used to Mapped to the value range (0,1).

5. The radar rotation angle adjustment method based on scenario interaction according to claim 4, characterized in that: The initial compensation angle is 10°.

6. The radar rotation angle adjustment method based on scenario interaction according to claim 4, characterized in that: The standard electromyographic signal is 20 μV.

7. The radar rotation angle adjustment method based on scenario interaction according to claim 4, characterized in that: The standard heart rate is 75 bpm.

8. The radar rotation angle adjustment method based on scenario interaction according to claim 1, characterized in that: The patient's heart rate is obtained by a sliding window mean filtering algorithm, where the formula for calculating the patient's heart rate is: , H is the heart rate, N is the window size, h i For the i Real-time heart rate at all times, h k is the real-time heart rate at the current moment, i and k All are positive integers.

9. The radar rotation angle adjustment method based on scenario interaction according to claim 1, characterized in that: The patient's electromyographic signal is obtained by the sliding window mean filtering algorithm, and the formula for calculating the patient's heart rate is: , E is the electromyographic signal, N is the window size, e i For the i Real-time heart rate at all times, e k is the real-time heart rate at the current moment, i and k All are positive integers.

10. A radar rotation angle adjustment system based on scenario interaction, comprising a processor and a memory, wherein the memory stores a computer program, characterized in that: The processor executes the computer program to implement the radar rotation angle adjustment method based on scenario interaction as described in any one of claims 1 to 9.

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