Plane interaction method and device based on radar scanning

Abstract

The invention relates to a plane interaction method and device based on radar scanning, and the method comprises the steps: determining the radar installation coordinates of a radar in a physical rectangular coordinate system of a projection plane, and determining the rotation offset between the zero-degree direction of the radar and the reference direction of the projection plane; controlling the radar to scan a scanning plane in a detection range, and identifying each target point of an interactive object on the scanning plane; determining a measurement distance from the radar to each target point and an initial detection angle of each target point relative to the zero-degree direction of the radar; based on the radar installation coordinate, the rotation offset, the measurement distance and the initial detection angle, calculating to obtain a pixel coordinate of each target point in a pixel coordinate system corresponding to the projection content; and determining an interaction operation based on the pixel coordinate, the continuous existence duration and the displacement change of each target point. According to the invention, the accuracy of plane interaction is improved.

Description

Technical Field

[0001] This application relates to the field of radar technology, and in particular to a planar interactive method and apparatus based on radar scanning. Background Technology

[0002] With the rapid iteration of human-computer interaction technology, radar-based planar interaction solutions, with their contactless and high-response characteristics, have been widely applied in diverse scenarios such as AR / VR interaction, smart exhibition halls, and industrial virtual assembly. This technology uses radar to detect the spatial position of interactive objects to obtain data on each point of the interactive object. After converting the data into pixel coordinates, it accurately determines the pixel position occupied by the interactive object in the projected content, ultimately enabling real-time interaction between the user and the projected content.

[0003] However, current mainstream radar planar interactive technologies still face numerous technical constraints. Firstly, there is the strong constraint of installation location. Existing solutions require the radar to be deployed within the interactive screen area, preventing flexible deployment outside the projection range. In large-scale projection scenarios, this not only disrupts the integrity of the image but also makes it difficult to adapt due to space limitations. Secondly, there is a shortcoming in positioning accuracy. Most technologies use relative coordinate systems for position calculations, and coordinate transformation errors accumulate point by point during the interaction process, leading to a continuous increase in positioning deviation. Thirdly, the calibration process is highly complex. These technologies generally rely on multi-point positioning correction, requiring calibration to be performed in a fixed corner. This is not only cumbersome and time-consuming but also requires specialized tools, significantly increasing the operational threshold.

[0004] The combination of the aforementioned technical defects makes it impossible for existing solutions to reliably and accurately obtain the pixel coordinates of each point in interactive objects. In large-size projection scenarios, this manifests as limited interaction range and incomplete pixel positions; in high-precision scenarios, the positioning deviation exceeds the allowable threshold; and in complex installation environments, it directly causes the system to malfunction, ultimately resulting in inaccurate planar interaction. Summary of the Invention

[0005] This application provides a planar interaction method and apparatus based on radar scanning to solve the problem of inaccurate planar interaction.

[0006] In a first aspect, this application provides a planar interaction method based on radar scanning, the method comprising: The radar installation coordinates in the physical Cartesian coordinate system of the projection surface are determined, and the rotational offset between the zero-degree direction of the radar and the reference direction of the projection surface is determined. The radar is located at any position inside or outside the projection surface, the projection surface is a physical plane used to display the projected content, the zero-degree direction of the radar is the radar's preset initial detection direction, and the reference direction of the projection surface is a coordinate axis direction in the physical Cartesian coordinate system of the projection surface. The radar is controlled to scan the scanning plane within the detection range to identify each target point of the interactive object on the scanning plane. The scanning plane of the radar and the projection plane are parallel to each other. The radar, the interactive object, the scanning plane and the projection plane are arranged in sequence along a direction perpendicular to the projection plane. Determine the measurement distance of the radar to each of the target points, and the initial detection angle of each target point relative to the zero-degree direction of the radar; Based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle, the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content are calculated. The interactive operation is determined based on the pixel coordinates, duration of existence, and displacement changes of each target point.

[0007] Optionally, determining the rotational offset between the zero-degree direction of the radar and the reference direction of the projection plane includes: The radar is controlled to scan the scanning plane within the detection range to determine the point cloud data corresponding to the reference object in the radar's polar coordinate system. The radar's offset angle in the zero-degree direction is adjusted according to the user's operation on the visual interface; The mapping relationship between the polar coordinate system of the radar and the physical rectangular coordinate system of the projection surface is updated based on the offset angle, and the point cloud position in the visualization interface is updated synchronously. If a confirmation command is detected, the currently adjusted offset angle is used as the rotational offset between the zero-degree direction of the radar and the reference direction of the projection plane, wherein the confirmation command is used to indicate that the point cloud data has covered the reference object on the scanning plane.

[0008] Optionally, based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle, the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content are calculated as follows: The effective angle is determined based on the difference between the initial detection angle and the rotation offset. Based on the effective angle, the radar installation coordinates, and the measurement distance, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane; The pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content are determined based on the physical coordinates of the target point, the physical size of the projection surface, the pixel size of the projected content, and the starting coordinates in the pixel coordinate system.

[0009] Optionally, if the angle difference between the effective angle and the specific angle is less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; in,( , ) represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. , ( ) represents the radar installation coordinates in the physical Cartesian coordinate system of the projection plane. This refers to the distance the radar travels to the target point.

[0010] Optionally, if the angle difference between the effective angle and the specific angle is not less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: The formula for calculating the first distance between the radar installation coordinates and the target point on the scanning plane is: ,in, The first distance, The vertical coordinate of the radar installation coordinates. The distance at which the radar reaches the target point. For effective angle; First angle The calculation formula is: ; Based on the angular range of the effective angle, the first distance, and the first angle, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane.

[0011] Optionally, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: when ; hour, ; in,( , () represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. The horizontal coordinate of the radar is set. The first distance, This is the first angle.

[0012] Optionally, the formula for calculating the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content is as follows: ,in,( , ) represents the pixel coordinates of the target point in the pixel coordinate system. , ) represents the horizontal and vertical starting coordinates in the pixel coordinate system. , Let W be the physical coordinates of the target point in the physical Cartesian coordinate system of the projection plane, W be the physical width of the projection plane, and H be the physical height of the projection plane. The pixel width of the projected content. This represents the pixel height of the projected content.

[0013] Secondly, this application provides a radar-scanning-based planar interactive device, the device comprising: The first determining module is used to determine the radar installation coordinates in the physical Cartesian coordinate system of the projection surface, and to determine the rotational offset between the zero-degree direction of the radar and the reference direction of the projection surface. The radar is located at any position inside or outside the projection surface, the projection surface is a physical plane for displaying the projected content, the zero-degree direction of the radar is the radar's preset initial detection direction, and the reference direction of the projection surface is a coordinate axis direction in the physical Cartesian coordinate system of the projection surface. The identification module is used to control the radar to scan the scanning plane within the detection range and identify each target point of the interactive object on the scanning plane. The scanning plane of the radar and the projection plane are parallel to each other. The radar, the interactive object, the scanning plane and the projection plane are arranged in sequence along a direction perpendicular to the projection plane. The second determining module is used to determine the measurement distance of the radar to each of the target points, and the initial detection angle of each target point relative to the zero-degree direction of the radar; The calculation module is used to calculate the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle. The third determination module is used to determine the interactive operation based on the pixel coordinates, duration of existence, and displacement change of each target point.

[0014] Optionally, the first determining module 801 is used for: The radar is controlled to scan the scanning plane within the detection range to determine the point cloud data corresponding to the reference object in the radar's polar coordinate system. The radar's offset angle in the zero-degree direction is adjusted according to the user's operation on the visual interface; The mapping relationship between the polar coordinate system of the radar and the physical rectangular coordinate system of the projection surface is updated based on the offset angle, and the point cloud position in the visualization interface is updated synchronously. If a confirmation command is detected, the currently adjusted offset angle is used as the rotational offset between the zero-degree direction of the radar and the reference direction of the projection plane, wherein the confirmation command is used to indicate that the point cloud data has covered the reference object on the scanning plane.

[0015] Optionally, the computing module 804 is used for: The effective angle is determined based on the difference between the initial detection angle and the rotation offset. Based on the effective angle, the radar installation coordinates, and the measurement distance, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane; The pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content are determined based on the physical coordinates of the target point, the physical size of the projection surface, the pixel size of the projected content, and the starting coordinates in the pixel coordinate system.

[0016] Optionally, if the angle difference between the effective angle and the specific angle is less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; in,( , ) represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. , ( ) represents the radar installation coordinates in the physical Cartesian coordinate system of the projection plane. This refers to the distance the radar travels to the target point.

[0017] Optionally, if the angle difference between the effective angle and the specific angle is not less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: The formula for calculating the first distance between the radar installation coordinates and the target point on the scanning plane is: ,in, The first distance, The vertical coordinate of the radar installation coordinates. The distance at which the radar reaches the target point. For effective angle; First angle The calculation formula is: ; Based on the angular range of the effective angle, the first distance, and the first angle, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane.

[0018] Optionally, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: when ; hour, ; in,( , () represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. The horizontal coordinate of the radar is set. The first distance, This is the first angle.

[0019] Optionally, the formula for calculating the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content is as follows: ,in,( , ) represents the pixel coordinates of the target point in the pixel coordinate system. , ) represents the horizontal and vertical starting coordinates in the pixel coordinate system. , Let W be the physical coordinates of the target point in the physical Cartesian coordinate system of the projection plane, W be the physical width of the projection plane, and H be the physical height of the projection plane. The pixel width of the projected content. This represents the pixel height of the projected content.

[0020] Thirdly, this application provides an electronic device, comprising: at least one communication interface; at least one bus connected to the at least one communication interface; at least one processor connected to the at least one bus; and at least one memory connected to the at least one bus.

[0021] Fourthly, this application also provides a computer storage medium storing computer-executable instructions for executing the radar-scan-based planar interaction method described in any of the preceding claims of this application.

[0022] The technical solutions provided in this application have the following advantages compared with the prior art: The radar is deployed at any planar location within or outside the projection plane, breaking through the physical constraint that traditional radars must be installed within the projection plane area. Then, the radar's installation coordinates in the physical Cartesian coordinate system of the projection plane are determined, along with the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane. Each target point of the interactive object on the radar's scanning plane is identified, and the straight-line measurement distance to each target point and the initial detection angle of each target point relative to the radar's zero-degree direction are determined. Next, based on the calibrated radar installation coordinates, rotational offset, and each target point's own measurement distance and initial detection angle, the pixel coordinates of each target point are determined. Since each target point is calculated independently based on calibrated fixed data and its own data, error propagation caused by traditional relative coordinate calculations is avoided, improving the accuracy of each target point's pixel coordinates. Finally, the interactive operation is determined based on each target point's pixel coordinates, duration of existence, and displacement change. This application achieves a breakthrough in radar installation constraints, simplifies the calibration process, and eliminates error accumulation, improving the accuracy of interactive operations during planar interaction. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0026] Figure 1 A schematic diagram of the system operation mechanism provided in the embodiments of this application; Figure 2 Signaling diagram of the detection process for interactive objects provided in the embodiments of this application; Figure 3 A schematic diagram of the data flow for non-contact planar interaction of radar provided in the embodiments of this application; Figure 4 A flowchart of a planar interaction method based on radar scanning is provided for embodiments of this application; Figure 5 A schematic diagram illustrating the principle of radar installation coordinates provided in the embodiments of this application; Figure 6 A schematic diagram illustrating the principle of determining the pixel position of a target point according to an embodiment of this application; Figure 7 The target point status recognition process of the radar planar interactive system provided in the embodiments of this application; Figure 8 This is a diagram showing the architecture and data flow of the radar planar interaction system; Figure 9 A schematic diagram of the structure of a planar interactive device based on radar scanning, provided for an embodiment of this application; Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0029] First, some terms used in this application will be explained, including the following:

[0030] Radar: A 2D planar scanning device capable of transmitting and receiving millimeter-wave signals; the scanning angle is not less than 120°, and it can output point cloud coordinates (presented in polar coordinates (r,θ)).

[0031] Scanning plane: a detection plane formed by radar beams, which is arranged parallel to the projection plane and the distance between the two planes is 5-50cm; a polar coordinate system with the radar as the origin is used.

[0032] Interactive objects: These are trigger objects used by users for interactive operations. Common forms include human hands or styluses. They can be effectively identified by radar within the scanning plane, with a minimum detectable size of 2cm.

[0033] Projection surface: a physical carrier used to support projected content, with a size ranging from 0.5 to 5 square meters, and spatial positioning using a physical rectangular coordinate system.

[0034] Projected content: is a digital interactive image generated by a projection device that can be accurately displayed on the projection surface, has a coordinate mapping relationship with physical space, and has a resolution of no less than 1920×1080.

[0035] Projection equipment: An optical device used to project digital content. It works based on the principle of optical projection, does not require physical connection with the projection surface, and has an effective projection distance of 1-10m.

[0036] The host is the core processing terminal of a radar planar interactive system. It enables communication between the radar and the projection equipment, runs coordinate transformation and interactive event generation algorithms, and supports real-time data processing and command issuance.

[0037] Figure 1 This is a schematic diagram of the system operation mechanism of this application. This application is mainly applied to radar contactless planar interaction scenarios, such as smart exhibition halls, AR interactive experience areas, and educational training touch demonstrations. Users can perform contactless operations on the scanning plane corresponding to the projection surface using their hands or styluses. The projection surface will display the digital content that responds to the operation in real time, realizing real-time interaction between physical operations and digital content.

[0038] The interactive solution employs a closed-loop real-time interaction process, with the following steps: Radar scanning and data acquisition: After the radar is activated, it continuously scans the plane it covers, capturing point cloud data corresponding to user actions within that plane, and transmitting the point cloud data to the host. Upon receiving the point cloud data, the host executes its internal processing flow: first, it converts the polar coordinate data output by the radar into physical rectangular coordinates corresponding to the projection surface; then, it converts the physical rectangular coordinates into pixel coordinates corresponding to the projected content; based on the pixel coordinates, it generates interactive instructions matching the user's actions. The host sends the interactive instructions to the projection device, which updates the projected content according to the instructions and projects the updated content onto the projection surface for display. After seeing the content on the projection surface through visual feedback, the user performs manual operations within the scanning plane, such as moving their hand or adjusting their position; the radar scans again to find the point cloud data corresponding to the new operation, repeating the above process of radar scanning, host processing, projection display, and user operation, thus achieving continuous real-time interaction.

[0039] In the radar-plane interactive system, the physical layer constructs the basic interaction link with three core elements: the radar forms a dedicated detection plane through millimeter-wave scanning, the projection device presents the content on the projection surface as a physical carrier using optical projection technology, and the user completes direct interaction with the system through interactive objects.

[0040] In the coordinate system mapping system that is compatible with the radar planar interaction system, the scanning plane uses the polar coordinates (r, θ) of the radar coordinate system to record the detection data, the projection plane uses the rectangular coordinates (x, y) of the physical rectangular coordinate system to mark the spatial position, and the projection content is digitally positioned using the pixel coordinates (px, py) of the pixel coordinate system.

[0041] Within the radar planar interactive system, the components work together through a clear relationship chain: the projection device and the projection surface have no physical connection, and the transmission logic follows the sequence of projection device → (optical projection) → projection surface → (display) → projected content, transforming digital content into a visual image.

[0042] The host computer (such as an industrial computer or embedded device), which serves as the core hardware, and the interactive software running on it constitute the data processing hub. The data flow follows the path of host → (interactive event) → interactive software → (screen update command) → projection device. The host computer enables multi-device linkage through the interface layer (connecting to the radar via USB / serial port, and to the projection device via HDMI / network). It relies on the processing layer to run coordinate transformation algorithms to complete multi-coordinate system data conversion, and generates interactive events such as touch and gestures through the event layer, ultimately building a complete interactive closed loop.

[0043] Figure 2 This is a signaling diagram illustrating the detection process for interactive objects. Figure 3 This is a schematic diagram of the data flow for non-contact planar interaction with radar. The following explains the scenario and overall process.

[0044] The projection surface is the physical interactive medium that users see, such as a white wall, electronic screen, or special screen. It is a rigid and flat canvas that is responsible for receiving the projected content.

[0045] Projected content refers to images or animations projected onto a projection plane by a projection device, such as interactive game interfaces, AR virtual buttons, and data visualization charts. It is bound to the physical space, and users can directly control this content with their gestures.

[0046] Radar is a 2D planar scanning device that emits and receives millimeter-wave signals. It has a scanning angle of ≥120° and can capture objects within a range of 5-50cm. It also outputs the target's distance and angle data (point cloud coordinates) and is specifically responsible for sensing the user's gestures.

[0047] The scanning plane is an invisible sensing layer formed by the radar beam. It is parallel to the projection plane and the distance between them is between 5 and 50 cm. As long as an interactive object enters this plane, it will be detected by the radar.

[0048] Gestures are user actions, such as clicking, swiping, or clenching a fist. They can also be assisted by a stylus. As long as the interactive object moves within the scanning plane, it can be regarded as an interactive command.

[0049] The interactive software runs on the host computer and can convert the point cloud data (physical coordinates) transmitted by the radar into pixel coordinates that the projected content can recognize. It can also determine the operation corresponding to the gesture (such as swiping to turn pages on the corresponding interface) and then send an image update command to the projection device.

[0050] The user is the main participant in the interaction. By making gestures within the scanning plane, the user interacts with the content on the projection plane and receives visual feedback from the projected content, thus forming an operational loop.

[0051] This application provides an example to illustrate the application scenario. The radar continuously emits millimeter waves, forming a scanning plane 5-50cm in front of the projection plane. It constantly monitors whether any objects enter this scanning plane. When a user places their hand into the scanning plane and makes a swiping gesture from left to right, the hand reflects the radar's millimeter wave signal. The radar detects the hand's position, generates point cloud data, and transmits the data to the host computer via USB / serial port. The host computer first converts the radar's polar coordinates into physical Cartesian coordinates of the projection plane, and then uses pixel mapping rules to convert them into pixel coordinates of the projected content. The interactive software recognizes this left-to-right displacement, interprets it as a PPT page-turning command, and immediately generates a screen update event, sending a command to the projection device. Upon receiving the command, the projection device updates the PPT on the projection plane, switching to the next page. The user sees the change in content and knows that the operation has taken effect.

[0052] The following will describe in detail a planar interaction method based on radar scanning provided in the embodiments of this application, taking its application to a host as an example. Figure 4 As shown, the specific steps are as follows: Step 401: Determine the radar installation coordinates in the physical Cartesian coordinate system of the projection plane, and determine the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane. The radar is located at any position inside or outside the projection plane, the projection plane is the physical plane used to display the projected content, the radar's zero-degree direction is the radar's preset initial detection direction, and the reference direction of the projection plane is a coordinate axis direction in the physical Cartesian coordinate system of the projection plane. Step 402: Control the radar to scan the scanning plane within the detection range and identify each target point of the interactive object on the scanning plane. The radar scanning plane and the projection plane are parallel to each other. The radar, interactive object, scanning plane and projection plane are arranged in sequence along a direction perpendicular to the projection plane. Step 403: Determine the measurement distance of the radar to each target point, and the initial detection angle of each target point relative to the zero-degree direction of the radar; Step 404: Based on the radar installation coordinates, rotation offset, measurement distance, and initial detection angle, calculate the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content; Step 405: Determine the interactive operation based on the pixel coordinates, duration of existence, and displacement change of each target point.

[0053] In step 401, the host computer first constructs a physical Cartesian coordinate system for the projection surface, sets the X and Y axis directions of the physical Cartesian coordinate system (e.g., the positive X-axis is horizontal to the right and the positive Y-axis is vertical downward), and defines any coordinate axis direction of this physical Cartesian coordinate system as the reference direction of the projection surface. The host computer then inputs the radar installation coordinates of the radar center point in this physical Cartesian coordinate system through the parameter configuration module.

[0054] Figure 5 A schematic diagram illustrating the principle of radar coordinate installation. First, a physical rectangular coordinate system is established for the projection surface, with the origin at the upper left corner of the projection surface. The coordinate directions include the X-axis (positive horizontally to the right, corresponding to the actual physical width W of the projection surface) and the Y-axis (positive vertically downward, corresponding to the actual physical height H of the projection surface). , Let be the radar installation coordinates in the physical Cartesian coordinate system of the projection plane, where It is the horizontal distance from the radar center point to the left edge of the projection plane (a positive number means the radar center point is on the right side of the projection plane, and a negative number means it is on the left side). This is the vertical distance from the radar's center point to the edge of the projection plane (a positive number indicates the radar's center point is below the projection plane, and a negative number indicates it's above). For example, if the radar is installed in the upper left of the projection plane, then... , Both can be negative.

[0055] In this application, the radar can be deployed at any planar location within or outside the projection plane, breaking through the physical constraint that traditional radars must be installed within the projection plane area.

[0056] Simultaneously, the host computer activates the visual calibration engine, guiding the user to select an unobstructed reference object within the projection area. Unobstructed means the reference object's location is free of obstructions and electromagnetic interference, allowing for clear radar scanning. This reference object serves as an independent calibration benchmark. The user adjusts the rotational offset between the radar's zero-degree direction and the projection surface's reference direction in real-time using angle sliders and saves the adjustment. The radar's zero-degree direction is its factory-preset initial detection reference direction, and the rotational offset compensates for deviations between the radar's installation angle and the projection surface's reference direction. This application eliminates the need for traditional multi-point positioning calibration procedures, resolving the cumbersome nature of traditional calibration processes.

[0057] In step 402, the host sends a scanning command to the radar to control the radar to perform millimeter-wave scanning on the scanning plane of the preset detection range. The scanning plane is parallel to the projection plane and the vertical spacing is 5-50cm. The radar, interactive object, scanning plane and projection plane are arranged in sequence along the direction perpendicular to the projection plane.

[0058] During the scanning process, the host first performs preliminary filtering on the raw point cloud data returned by the radar, automatically removing preset occlusion or interference areas, such as invalid point clouds in areas covered by wall supports or electromagnetic interference sources. It can specify filtering out areas within 50-100mm of the boundary, and only identify each target point formed on the scanning plane by interactive objects (such as palms or styluses) within the unobstructed area. This achieves effective avoidance of occlusion or interference areas, ensuring the validity and purity of the target point data.

[0059] In step 403, the host computer independently acquires and receives data for each identified target point through the radar drive interface, obtaining two sets of core data: the straight-line measurement distance from the radar to the target point, and the initial detection angle of the target point relative to the radar's zero-degree direction. The initial detection angle of the target point relative to the radar's zero-degree direction refers to the angle between the target point and the radar's zero-degree direction, measured counterclockwise or clockwise with the radar's zero-degree direction as the reference. This angle is the radar's original detection value for the target point, without angle deviation compensation. The measurement data for each target point is independently acquired and generated, without relying on the measurement results of other target points, laying the data foundation for subsequent independent coordinate calculations.

[0060] In step 404, the host computer performs independent coordinate calculations for each target point based on the calibrated radar installation coordinates and rotation offset, combined with the measured distance and initial detection angle of each target point. During the calculation, the host computer calculates the coordinates of each target point based on the two fixed parameters of radar installation coordinates and rotation offset, along with the target point's own measured distance and initial detection angle. It does not use the traditional relative coordinate calculation method, meaning it does not use the coordinate result of the previous target point as the calculation basis for the next target point, thus fundamentally cutting off the error propagation link and eliminating the error propagation and accumulation problems caused by traditional relative coordinate calculations. Afterwards, the host computer converts the actual physical coordinates of the target point into its pixel coordinates in the pixel coordinate system corresponding to the projected content.

[0061] In step 405, within the radar planar interaction system, the system first preprocesses the pixel coordinates of each target point, verifying whether it is within the preset effective interaction area, eliminating environmental interference points outside the area, and smoothing the pixel coordinates of multiple consecutive frames to eliminate random offset errors caused by detection. Then, a unique identifier is bound to each effective target point within the area to achieve independent tracking. Next, the system counts the duration of the target point's existence. Newly detected target points enter a pending confirmation state; only those that persist for a set duration are considered valid touch points. If a point disappears before reaching the set duration, it is further distinguished between momentary environmental interference and a single click operation. The system then monitors the displacement changes of the touch point in real time, comparing the positional differences between adjacent frames. If the positional difference exceeds a predetermined range, it is determined to be a swipe operation; if there is no significant displacement for a long period and the duration is sufficient, it is determined to be a long press operation; if there is no displacement at all, it remains in a static pressed state. When a target point disappears, the system first puts it into a release pending confirmation state. This state persists for a certain duration before being considered fully released, thus avoiding misjudgments caused by momentary interruptions in radar detection.

[0062] This application filters out invalid interference points in advance by filtering the effective area of ​​pixel coordinates, reduces positional errors at the detection level by smoothing coordinates, filters out instantaneous interference such as objects passing by and false triggering operations by continuous multi-frame verification, accurately distinguishes operations such as swiping, long pressing, and static pressing by setting appropriate displacement ranges for different interaction types, and achieves independent tracking of multiple touch points by relying on the unique identifier of the target point to avoid mutual interference when multiple targets are operated simultaneously. The application can also flexibly adjust the judgment thresholds of duration and displacement according to the actual use scenario to ensure the accuracy and stability of interaction operation judgment.

[0063] In this application, the radar is deployed at any planar location within or outside the projection plane, breaking through the physical constraint that traditional radars must be installed within the projection plane area. Then, the radar's installation coordinates in the physical Cartesian coordinate system of the projection plane are determined, along with the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane. Each target point of the interactive object on the radar's scanning plane is identified, and the measurement distance to each target point and the initial detection angle of each target point relative to the radar's zero-degree direction are determined. Next, based on the calibrated radar installation coordinates, rotational offset, and each target point's own measurement distance and initial detection angle, the pixel coordinates of each target point are determined. Since each target point is calculated independently based on calibrated fixed data and its own data, error propagation caused by traditional relative coordinate calculations is avoided, improving the accuracy of each target point's pixel coordinates. Finally, the interactive operation is determined based on each target point's pixel coordinates, duration of existence, and displacement change. This application achieves a breakthrough in radar installation constraints, simplifies the calibration process, and eliminates error accumulation, improving the accuracy of interactive operations during planar interaction.

[0064] As an optional implementation, in step 401, determining the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane includes: Step S11: Control the radar to scan the scanning plane within the detection range and determine the point cloud data corresponding to the reference object in the radar's polar coordinate system; Step S12: Adjust the radar's offset angle in the zero-degree direction according to the user's operation on the visual interface; Step S13: Update the mapping relationship between the radar's polar coordinate system and the physical rectangular coordinate system of the projection surface based on the offset angle, and simultaneously update the point cloud position in the visualization interface. Step S14: If a confirmation command is detected, the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane is determined based on the currently adjusted offset angle. The confirmation command is used to indicate that the point cloud data has covered the reference object on the scanning plane.

[0065] In step S11, the user can place a reference object at any position in the projection area, with the only restriction being that it must avoid the fixed scanning blind zone around the radar, such as the close-range area within 5cm directly in front of the radar probe. Then, the host controls the radar to continuously scan the scanning plane within the specified detection range with millimeter waves to determine the point cloud data corresponding to the reference object in the scanning plane.

[0066] To improve the accuracy of point cloud recognition, the system recommends using isolated objects such as a hand, a water bottle, or a dedicated calibration column as reference objects. These objects have clear physical outlines and no complex occlusions, enabling the generation of point cloud data with distinct features. After the radar completes the scan, it converts the spatial position information of the detected reference objects into point cloud data in polar coordinates (r, θ) and transmits it synchronously to the host computer for preliminary processing.

[0067] In step S12, the host computer displays the point cloud data transmitted by the radar in real time on the visualization interface using set markers, such as red point clouds. The user needs to visually compare two key aspects: first, whether the point cloud aggregation position corresponds to the physical position of the actual reference object; and second, whether the distribution pattern of the point cloud matches the actual physical outline of the reference object. If the comparison results are inconsistent, the radar's offset angle in the zero-degree direction needs to be adjusted. The goal of the adjustment is to ensure that the set point cloud markers completely cover the position of the actual reference object. The user can fine-tune the radar's offset angle in the zero-degree direction using the angle slider in the visualization interface. The angle adjustment ranges from 0 to 360°, with an adjustment accuracy of up to 0.1°. After each slider operation, the host computer refreshes the display position of the point cloud in real time, allowing the user to observe the adjustment effect.

[0068] In step S13, the host computer updates the mapping relationship between the radar polar coordinate system and the physical rectangular coordinate system of the projection surface in real time based on the offset angle currently adjusted by the user, and simultaneously refreshes the point cloud position in the visualization interface. The underlying principle of this adjustment is that by modifying the zero-degree angle offset parameter, the spatial mapping relationship between the radar polar coordinate system and the physical rectangular coordinate system of the projection surface can be restored to orthogonality. From the perspective of spatial correspondence, a correct angle offset will create a one-to-one correspondence between the point cloud position and the physical spatial position. When the point cloud begins to fit the reference object, it proves that the radar's distance measurement (point cloud aggregation position) and angle measurement (point cloud distribution pattern) have gradually become accurate. From the perspective of error correction, in the initial state, the point cloud will be misaligned with the object due to the angle deviation. During the adjustment process, the point cloud will rotate and move synchronously with the modification of the angle parameter until the center of the point cloud coincides with the center of the object and the outline is completely matched.

[0069] In step S14, if the host detects the confirmation command issued by the user, indicating that the user has determined that the point cloud data has completely covered the reference object on the scanning plane, the currently adjusted offset angle will be used as the final rotational offset between the radar zero-degree direction and the projection plane reference direction and saved. To ensure the effectiveness of the calibration, the user can perform a secondary confirmation through actual verification methods: slightly move the reference object and observe whether the point cloud in the interface moves synchronously; or change the reference object or adjust its placement in multiple locations within the projection area to verify the accuracy of the point cloud position under different scenarios. When multiple verifications meet the condition of precise alignment between the point cloud and the actual object, it proves that the radar angle measurement value has been correctly compensated, and the coordinate system transformation relationship between the radar and the projection plane has been accurately established, thus the calibration process is officially completed.

[0070] This application supports setting up reference objects in any unobstructed location. When the reference object is obstructed, it can be immediately replaced with a new position for recalibration. The rotation offset is automatically recalculated when the reference object is switched.

[0071] This application significantly lowers the operational threshold for radar coordinate system calibration by allowing for flexible reference object selection and intuitive visualization calibration, enabling high-precision calibration without the need for specialized tools. The 0.1° angle adjustment accuracy and real-time refreshed point cloud feedback mechanism ensure the orthogonality and accuracy of the coordinate system mapping, effectively eliminating positioning errors caused by initial angle deviations. Furthermore, the multi-location physical verification process further guarantees the stability and robustness of the calibration results. The final technical effects are reflected in three aspects: First, improved calibration efficiency; compared to traditional multi-point positioning correction, this process saves more than 60% of calibration time and requires no professional personnel. Second, optimized positioning accuracy; the alignment error between the point cloud and the physical object can be controlled within 1 pixel, laying the foundation for accurate conversion of target point pixel coordinates. Third, enhanced scene adaptability; even in complex installation environments, users can flexibly select reference objects to complete calibration, overcoming the limitation of fixed calibration points being easily obstructed in traditional solutions, and meeting the interactive needs of diverse scenarios such as large-size projection and non-standard installations.

[0072] As an optional implementation, in step 404, based on the radar installation coordinates, rotation offset, measurement distance, and initial detection angle, the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content are calculated, including: Step S21: Determine the effective angle based on the difference between the initial detection angle and the rotation offset; Step S22: Determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane based on the effective angle, radar installation coordinates, and measurement distance; Step S23: Determine the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content based on the physical coordinates of the target point, the physical size of the projection surface, the pixel size of the projected content, and the starting coordinates in the pixel coordinate system.

[0073] In step S21, the host obtains the initial detection angle of the radar at the target point of the interactive object. After obtaining the rotational offset α between the radar zero-degree direction and the projection plane reference direction from the previous calibration, the effective angle is determined by calculating the difference between the two. The specific formula is as follows: ,in, For an effective angle, The initial detection angle, This is the rotation offset.

[0074] The initial detection angle only reflects the target point's azimuth relative to the radar's zero-degree direction. However, there is often an angular deviation between the radar's zero-degree direction and the projection surface's reference direction (such as the Y-axis of the projection surface's physical rectangular coordinate system). This deviation directly leads to inaccurate target point azimuth determination. By subtracting a pre-calibrated rotation offset α, the initial detection angle can be compensated and corrected, resulting in a more effective angle. It can accurately characterize the actual orientation of the target point relative to the reference direction of the projection plane, providing a unified and accurate angle reference for subsequent coordinate conversion.

[0075] In step S22, the host computer determines the effective angle based on the obtained angle. Pre-configured radar installation coordinates ( , This refers to the position of the radar in the physical rectangular coordinate system of the projection plane, and the measured distance di of the radar to the target point. The physical coordinates of the target point in the physical rectangular coordinate system of the projection plane are calculated in two scenarios. , ).

[0076] I. Special angle scenarios.

[0077] If the angle difference between the effective angle and the specific angles 0°, 90°, and 180° is less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: From an effective angle When the angle difference between them is less than a preset threshold, that is... If the angle is close to 0°, it means the target point is directly above the radar. .

[0078] From an effective angle When the angle difference between them is less than a preset threshold, that is... If the angle is close to 90°, it means the target point is directly to the right of the radar. .

[0079] From an effective angle When the angle difference between them is less than a preset threshold, that is... A near 180° angle indicates that the target point is directly below the radar. .

[0080] in,( , ) represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. , ( ) represents the radar installation coordinates in the physical Cartesian coordinate system of the projection plane. This refers to the distance the radar travels to the target point.

[0081] II. Typical angle scenarios.

[0082] The first step is to calculate the first distance between the radar installation coordinates and the target point on the scanning plane using the law of cosines. The formula is: ,in, The first distance, The vertical coordinate of the radar installation coordinates. The distance at which the radar reaches the target point. This is an effective angle.

[0083] In the conventional angle scenario for calculating the physical coordinates of a target point, the triangle is a geometric model constructed based on three spatial points: the radar installation location, the projection plane reference point, and the target point. The specific vertex definitions are as follows: Vertex A: The installation position of the radar in the physical rectangular coordinate system of the projection plane, with coordinates ( , ),in This is the vertical distance from the radar to the boundary (Y=0) on the projection plane.

[0084] Vertex V: The vertical reference point of the radar on the projection plane, with coordinates ( , ), that is, the orthographic projection point of the radar on the boundary of the projection plane, therefore the vertical distance from A to V is .

[0085] Vertex R: The target point of the interactive object in the scanning plane, which is the core point where the physical coordinates need to be calculated.

[0086] The three vertices form △AVR, where AV is the vertical reference side of the radar reaching the boundary of the projection plane, AR is the measured distance side of the radar reaching the target point, and VR is the associated side from the reference point to the target point. This triangle is the core geometric carrier for coordinate transformation under conventional angles.

[0087] The first and core step is to establish the spatial correlation between the reference point and the target point: radar measurements It can only represent the straight-line distance from the radar to the target point and cannot be directly mapped to the rectangular coordinate system of the projection surface; however, after calculating RV through the cosine theorem, the polar coordinate ranging data of the radar is transformed into the distance from the reference point of the projection surface to the target point.

[0088] The second step is to calculate the first angle β of the triangle vertex V using the sine theorem. The formula is: .

[0089] The second step is to determine the azimuth of the target point relative to the reference point: RV only provides the straight-line distance from V to R, while β specifies the horizontal or vertical orientation of R relative to the reference edge AV. Combined with the orientation rules of the rectangular coordinate system of the projection plane, the horizontal (x-axis) and vertical (y-axis) coordinate components of the target point can be further derived through β.

[0090] The third step, according to The physical coordinates of the target point are determined by the angle range, the first distance, and the first angle, using the following formula: when ; hour, .

[0091] in,( , () represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. The horizontal coordinate of the radar is set. The first distance, This is the first angle.

[0092] In step 203, after obtaining the physical coordinates of the target point ( , After that, combine the physical dimensions of the projection surface (physical width W, physical height H) and the pixel dimensions of the projected content (pixel width) Pixel height The physical coordinates are converted to pixel coordinates using a proportional mapping algorithm, along with the starting coordinates (startx, starty) of the pixel coordinate system. The specific formula is as follows: ,in,( , ) represents the pixel coordinates of the target point in the pixel coordinate system. , ) represents the horizontal and vertical starting coordinates in the pixel coordinate system. , Let be the physical coordinates of the target point in the physical Cartesian coordinate system of the projection plane, W be the physical width of the projection plane, and H be the physical height of the projection plane. The pixel width of the projected content. This represents the pixel height of the projected content.

[0093] The core of this application is the spatial decoupling of the radar from the projection surface (the radar can be installed at any position inside or outside the projection surface), and the spatial offset and angular deviation between the radar's polar coordinate system and the physical rectangular coordinate system of the projection surface. Through geometric modeling of the △AVR, the radar's local polar coordinate data ( , ), and convert them into reference associated data of the global rectangular coordinate system of the projection plane ( , ), and then based on Derivation and This enables precise decoupling and mapping between two coordinate systems.

[0094] Traditional methods using relative coordinate systems lead to point-by-point error accumulation, while the independent position calculation engine in this application requires that the coordinates of each target point be calculated based on an absolute reference. The geometric algorithm for the △AVR uses radar installation coordinates. With the boundary reference point V on the projection plane as the absolute reference, the coordinate calculation of each target point is completed independently, without relying on the coordinate data of the previous target point. Therefore, error transmission and accumulation can be avoided from the source, ensuring positioning accuracy.

[0095] Figure 6 A schematic diagram illustrating the principle of determining the pixel position of a target point, with effective angles. : is the correction angle after subtracting the rotation offset from the initial radar detection angle, representing the actual azimuth of the target point relative to the reference direction of the projection plane.

[0096] Radar position A: Corresponds to the radar's installation coordinates in the physical rectangular coordinate system of the projection plane. The distance AV in the diagram is... It is the vertical distance (i.e., the ordinate of the radar installation coordinates) from the edge of the projection plane (the location of projection point V).

[0097] Projection point V: is the vertical reference point of the radar on the projection plane (the orthographic projection of the radar installation position on the projection plane).

[0098] Target point R: is the target point to be located within the interactive object in the scanning plane, at a distance AR = It is the measured distance from the radar to the target point.

[0099] β angle: is the angle between the radar position A and the target point R at the projection point V. It is a key azimuth parameter for subsequent calculation of the physical coordinates of the target point.

[0100] Figure 6 The underlying principle is to construct a △AVR triangle (vertices are radar position A, projection point V, and target point R), and then use the radar's polar coordinate detection data (range) to... Effective angle The parameters (distance RV, angle β) are transformed into the correlation parameters between the projection surface reference point (V) and the target point (R), realizing the spatial mapping from the radar local polar coordinate system to the projection surface global rectangular coordinate system.

[0101] Figure 6 The process logic is as follows.

[0102] Input known parameters: This will determine the effective angle. Radar installation parameters (distance AV= ), the measured distance of the radar to the target point (AR= () as input.

[0103] Calculating RV using the Law of Cosines: Based on the side-angle relationship of △AVR (given two sides) , and included angle The distance RV from the projection point V to the target point R is calculated using the law of cosines.

[0104] Calculating the β angle using the Law of Sines: Based on the known sides of △AVR ( , RV) and corresponding angle ( The included angle β at the projection point V is calculated using the sine theorem.

[0105] Through this process, the radar's detection data is transformed into distance and angle parameters in the projection plane's reference coordinate system, providing the core geometric basis for subsequent calculations of the target point's coordinates in the projection plane's physical rectangular coordinate system.

[0106] Figure 7 The target point status recognition process of the radar planar interactive system, including the flow and detailed logic of each state, is as follows.

[0107] The target points detected by radar are first converted into pixel coordinates by the coordinate transformation core, and then filtered by the event effective area of ​​the parameter configuration system (to remove interference points outside the boundary) to become potential interaction points.

[0108] The process starts from the initial state NewContact (potential interaction point), which corresponds to the first potential interaction point detected in the current frame. At this time, the potential interaction point has not yet been assigned a unique ID and has not passed the persistence verification. It will then directly transition to the PendingDown (pending confirmation press) state.

[0109] Entering the PendingDown state indicates that a potential interaction point still exists but has not reached the confirmation threshold. This state will last for 2 frames (approximately 66ms, which is the state verification period used to filter out momentary interference interaction points). If the potential interaction point disappears in this state, it will directly switch to the Releasing state. If the potential interaction point continues to exist for 2 frames, it will switch to the ActiveDown state.

[0110] The ActiveDown state means that the potential interaction point has passed the persistence verification and become a touch point. The system will assign a unique Touch ID to it and generate a DOWN event. In this state, if the touch point position changes more than a threshold (typically 5 pixels), it will switch to the Moving state.

[0111] Once in the Moving state, it means that the contact is in continuous displacement, and the system will continuously generate MOVE events. If the contact continues to move in this state, it will remain in the Moving state; if the contact disappears, it will switch to the Releasing state.

[0112] When the touch disappears in the ActiveDown or Moving state, it will enter the Releasing (pending confirmation of release) state, which will last for 3 frames (about 100ms). If the touch reappears during this period, it will return to the PendingDown state. If the touch disappearance state lasts for 3 frames, it will enter the Released state.

[0113] In the Released state, once the touch point disappears and confirmation is received, the system will reclaim the previously assigned TouchID and generate an UP event.

[0114] In this application, the target point is a discrete spatial point obtained by radar after scanning interactive objects (such as hands or styluses) within the scanning plane; its core attribute is location information. The touch point is a functional point formed by the system based on the target point and filtered according to interaction validity rules; its core attributes are location and interaction state. To be assigned a unique Touch ID, it must meet conditions such as persisting within the valid event area for a threshold (e.g., 2 frames), and be associated with interaction attributes such as duration of persistence and displacement changes. Its core function is to trigger interactive events; it is the core object of the event simulation system (e.g., determined as a press (ActiveDown), move (Moving), or click (TapEvent)), essentially an encapsulation of target points with interactive significance.

[0115] Table 1 is the state transition condition table.

[0116] Table 1

[0117] The technical parameters in this application are shown in Table 2.

[0118] Table 2

[0119] Figure 8 This is the architecture and data flow diagram of the radar planar interaction system. The functions of each component and the data interaction process are as follows.

[0120] Parameter configuration module: provides ( ) to the coordinate transformation core , ), that is, the installation coordinates of the radar in the physical rectangular coordinate system of the projection surface, which serve as the spatial reference for coordinate transformation.

[0121] Calibration Engine: Provides to the coordinate transformation core This refers to the rotational offset between the radar zero-degree direction and the reference direction of the projection plane, which is used to compensate for the initial detection angle.

[0122] Radar driver interface: provides di to the coordinate transformation core. , which is the measured distance of the radar to the target point and the initial detection angle of the target point relative to the radar zero-degree direction, is the original position data for coordinate transformation.

[0123] The core of coordinate transformation is to receive the above three types of input parameters, execute the coordinate transformation logic, and finally output ( , The target point is located at the pixel coordinates corresponding to the projected content, and these pixel coordinates are passed to the event simulation system.

[0124] Event simulation system: Determines interactive operations based on the pixel coordinates of the target point, its duration, and displacement changes.

[0125] This application also provides a planar interactive device based on radar scanning, such as... Figure 9 As shown, the device includes: The first determining module 901 is used to determine the radar installation coordinates in the physical rectangular coordinate system of the projection surface, and to determine the rotational offset between the zero-degree direction of the radar and the reference direction of the projection surface. The radar is located at any position inside or outside the projection surface, the projection surface is a physical plane used to display the projected content, the zero-degree direction of the radar is the radar's preset initial detection direction, and the reference direction of the projection surface is a coordinate axis direction in the physical rectangular coordinate system of the projection surface. The identification module 902 is used to control the radar to scan the scanning plane within the detection range and identify each target point of the interactive object on the scanning plane. The radar scanning plane and the projection plane are parallel to each other. The radar, the interactive object, the scanning plane and the projection plane are arranged in sequence along a direction perpendicular to the projection plane. The second determining module 903 is used to determine the measurement distance of the radar to each target point, and the initial detection angle of each target point relative to the zero-degree direction of the radar; The calculation module 904 is used to calculate the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content based on the radar installation coordinates, rotation offset, measurement distance and initial detection angle. The third determining module 905 is used to determine the interactive operation based on the pixel coordinates, duration of existence and displacement change of each target point.

[0126] Optionally, the first determining module 901 is used for: The control radar scans the scanning plane within the detection range to determine the point cloud data corresponding to the reference object in the radar's polar coordinate system; Adjust the radar's offset angle in the zero-degree direction based on the user's actions on the visual interface; The mapping relationship between the radar's polar coordinate system and the physical rectangular coordinate system of the projection surface is updated based on the offset angle, and the point cloud position in the visualization interface is updated simultaneously. If a confirmation command is detected, the rotational offset between the radar's zero-degree direction and the reference direction of the projection plane is determined by the currently adjusted offset angle. The confirmation command indicates that the point cloud data has covered the reference object on the scanning plane.

[0127] Optionally, the computing module 904 is used for: The effective angle is determined based on the difference between the initial detection angle and the rotation offset. Based on the effective angle, radar installation coordinates, and measurement distance, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane; Based on the physical coordinates of the target point, the physical dimensions of the projection surface, the pixel dimensions of the projected content, and the starting coordinates in the pixel coordinate system, determine the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content.

[0128] Optionally, if the angle difference between the effective angle and the specific angle is less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; in,( , ) represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. , ( ) represents the radar installation coordinates in the physical Cartesian coordinate system of the projection plane. This refers to the distance the radar travels to the target point.

[0129] Optionally, if the angle difference between the effective angle and the specific angle is not less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: The formula for calculating the first distance between the radar mounting coordinates and the target point on the scanning plane is: ,in, The first distance, The vertical coordinate of the radar installation coordinates. The distance at which the radar reaches the target point. For effective angle; First angle The calculation formula is: ; Based on the effective angle range, the first distance, and the first angle, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane.

[0130] Optionally, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: when ; hour, ; in,( , () represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. The horizontal coordinate of the radar is set. The first distance, This is the first angle.

[0131] Optionally, the formula for calculating the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content is: ,in,( , ) represents the pixel coordinates of the target point in the pixel coordinate system. , ) represents the horizontal and vertical starting coordinates in the pixel coordinate system. , Let be the physical coordinates of the target point in the physical Cartesian coordinate system of the projection plane, W be the physical width of the projection plane, and H be the physical height of the projection plane. The pixel width of the projected content. This represents the pixel height of the projected content.

[0132] like Figure 10 As shown, this application provides an electronic device including a processor 1001, a communication interface 1002, a memory 1003, and a communication bus 1004, wherein the processor 1001, the communication interface 1002, and the memory 1003 communicate with each other through the communication bus 1004.

[0133] Memory 1003 is used to store computer programs.

[0134] In one embodiment of this application, when the processor 1001 executes the program stored in the memory 1003, it implements the planar interaction method based on radar scanning provided in any of the foregoing method embodiments.

[0135] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the radar-scan-based planar interaction method provided in any of the foregoing method embodiments.

[0136] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0137] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0138] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one," "an," and "described" as used herein may also mean including the plural forms. The terms "comprising," "including," "containing," and "having" are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0139] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A planar interaction method based on radar scanning, characterized in that, The method includes: The radar installation coordinates in the physical Cartesian coordinate system of the projection surface are determined, and the rotational offset between the zero-degree direction of the radar and the reference direction of the projection surface is determined. The radar is located at any position inside or outside the projection surface, the projection surface is a physical plane used to display the projected content, the zero-degree direction of the radar is the radar's preset initial detection direction, and the reference direction of the projection surface is a coordinate axis direction in the physical Cartesian coordinate system of the projection surface. The radar is controlled to scan the scanning plane within the detection range to identify each target point of the interactive object on the scanning plane. The scanning plane of the radar and the projection plane are parallel to each other. The radar, the interactive object, the scanning plane and the projection plane are arranged in sequence along a direction perpendicular to the projection plane. Determine the measurement distance of the radar to each of the target points, and the initial detection angle of each target point relative to the zero-degree direction of the radar; Based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle, the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content are calculated. The interactive operation is determined based on the pixel coordinates, duration of existence, and displacement changes of each target point.

2. The method according to claim 1, characterized in that, Determining the rotational offset between the zero-degree direction of the radar and the reference direction of the projection plane includes: The radar is controlled to scan the scanning plane within the detection range to determine the point cloud data corresponding to the reference object in the radar's polar coordinate system. The radar's offset angle in the zero-degree direction is adjusted according to the user's operation on the visual interface; The mapping relationship between the polar coordinate system of the radar and the physical rectangular coordinate system of the projection surface is updated based on the offset angle, and the point cloud position in the visualization interface is updated synchronously. If a confirmation command is detected, the currently adjusted offset angle is used as the rotational offset between the zero-degree direction of the radar and the reference direction of the projection plane, wherein the confirmation command is used to indicate that the point cloud data has covered the reference object on the scanning plane.

3. The method according to claim 1, characterized in that, Based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle, the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content are calculated as follows: The effective angle is determined based on the difference between the initial detection angle and the rotation offset. Based on the effective angle, the radar installation coordinates, and the measurement distance, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane; The pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content are determined based on the physical coordinates of the target point, the physical size of the projection surface, the pixel size of the projected content, and the starting coordinates in the pixel coordinate system.

4. The method according to claim 3, characterized in that, If the angle difference between the effective angle and the specific angle is less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; From an effective angle When the angle difference between them is less than a preset threshold, ; in,( , ) represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. , ( ) represents the radar installation coordinates in the physical Cartesian coordinate system of the projection plane. This refers to the distance the radar travels to the target point.

5. The method according to claim 3, characterized in that, If the angle difference between the effective angle and the specific angle is not less than a preset threshold, the formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: The formula for calculating the first distance between the radar installation coordinates and the target point on the scanning plane is: ,in, The first distance, The vertical coordinate of the radar installation coordinates. The distance at which the radar reaches the target point. For effective angle; First angle The calculation formula is: ; Based on the angular range of the effective angle, the first distance, and the first angle, determine the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane.

6. The method according to claim 5, characterized in that, The formula for calculating the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane is: when ; hour, ; in,( , () represents the physical coordinates of the target point in the physical rectangular coordinate system of the projection plane. The horizontal coordinate of the radar is set. The first distance, This is the first angle.

7. The method according to claim 3, characterized in that, The formula for calculating the pixel coordinates of the target point in the pixel coordinate system corresponding to the projected content is as follows: ,in,( , ) represents the pixel coordinates of the target point in the pixel coordinate system. , ) represents the horizontal and vertical starting coordinates in the pixel coordinate system. , Let be the physical coordinates of the target point in the physical Cartesian coordinate system of the projection plane, W be the physical width of the projection plane, and H be the physical height of the projection plane. The pixel width of the projected content. This represents the pixel height of the projected content.

8. A planar interactive device based on radar scanning, characterized in that, The device includes: The first determining module is used to determine the radar installation coordinates in the physical Cartesian coordinate system of the projection surface, and to determine the rotational offset between the zero-degree direction of the radar and the reference direction of the projection surface. The radar is located at any position inside or outside the projection surface, the projection surface is a physical plane for displaying the projected content, the zero-degree direction of the radar is the radar's preset initial detection direction, and the reference direction of the projection surface is a coordinate axis direction in the physical Cartesian coordinate system of the projection surface. The identification module is used to control the radar to scan the scanning plane within the detection range and identify each target point of the interactive object on the scanning plane. The scanning plane of the radar and the projection plane are parallel to each other. The radar, the interactive object, the scanning plane and the projection plane are arranged in sequence along a direction perpendicular to the projection plane. The second determining module is used to determine the measurement distance of the radar to each of the target points, and the initial detection angle of each target point relative to the zero-degree direction of the radar; The calculation module is used to calculate the pixel coordinates of each target point in the pixel coordinate system corresponding to the projected content based on the radar installation coordinates, the rotation offset, the measurement distance, and the initial detection angle. The third determination module is used to determine the interactive operation based on the pixel coordinates, duration of existence, and displacement change of each target point.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-7.

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