A robot autonomous obstacle crossing method, system and storage medium

Abstract

The application provides a robot autonomous obstacle-crossing method, system and storage medium, and relates to the technical field of robot motion planning.The method comprises the following steps: determining, by a pressure sensing device, whether a snake robot contacts an obstacle in a running direction; determining, by an image acquisition device, a current obstacle type of the obstacle; determining a motion posture of a head joint according to the current obstacle type; determining an inclination angle of the obstacle relative to the head joint according to the motion posture; updating a general gait curve according to the inclination angle to obtain an obstacle step curve; and controlling the snake robot to cross the obstacle according to the obstacle step curve.The application significantly improves the motion effect of the snake robot when encountering an obstacle by fusing pressure sensing and visual information.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot motion planning, in particular to a robot autonomous obstacle crossing method and system and a storage medium. BACKGROUND

[0002] At present, multi-joint bionic robots are attracting more and more attention due to their own super-redundant degrees of freedom. Among them, a snake robot is a widely used multi-joint bionic robot. The snake robot can adapt to complex motion scenarios by generating different motion gaits. For example, a traveling wave gait is used as the main motion gait of the robot in flat terrain to control the robot to move in the direction of the snake curve.

[0003] In the related art, when the snake robot performs the traveling wave gait, if a small unknown obstacle is encountered on the path, the snake robot will collide with the obstacle, which greatly affects the motion speed and running efficiency. When a larger unknown obstacle is encountered on the path, due to the angle of view, the snake robot cannot observe all the parameters of the obstacle using a camera or a laser radar, and can only change the path to bypass the obstacle. The above two cases will cause the snake robot to need to make complex motion adjustments when encountering obstacles, thereby affecting the motion effect of the snake robot. SUMMARY

[0004] The problem solved by the present application is how to improve the motion effect of the snake robot when encountering obstacles.

[0005] To solve the above problems, the present application provides a robot autonomous obstacle crossing method, system and storage medium.

[0006] In a first aspect, the present application provides a robot autonomous obstacle crossing method, which is applied to a snake robot, the snake robot comprising a head joint and a plurality of pitch joints, the head joint and all the pitch joints being connected in turn, wherein the head joint is provided with a pressure sensing device and an image acquisition device;

[0007] The robot autonomous obstacle crossing method comprises:

[0008] When the snake robot performs a normal traveling wave gait according to a normal gait curve, whether the snake robot contacts an obstacle in the direction of travel is determined by the pressure sensing device;

[0009] When the snake robot contacts the obstacle, the current obstacle type of the obstacle is determined by the image acquisition device;

[0010] According to the current obstacle type, the motion posture of the head joint is determined;

[0011] determine an inclination angle of the obstacle relative to the head joint according to the motion posture;

[0012] update the common gait curve according to the inclination angle to obtain an obstacle step curve;

[0013] control each of the pitch joints of the snake robot to sequentially perform obstacle climbing according to the obstacle step curve until the last pitch joint completes obstacle climbing.

[0014] Optionally, the pressure sensing device is arranged on a contact surface of the head joint and the ground, and the determination of whether the snake robot contacts the obstacle in the motion direction includes:

[0015] detecting, by the pressure sensing device, a surface pressure of the head joint in the motion direction; when a pressure pulse output by the pressure sensing device is acquired, it is determined that the surface has the surface pressure, and when the pressure pulse output by the pressure sensing device is not acquired, it is determined that the surface does not have the surface pressure;

[0016] when the surface has the surface pressure, it is determined that the snake robot does not contact the obstacle in the motion direction;

[0017] when the surface does not have the surface pressure, it is determined that the snake robot contacts the obstacle in the motion direction.

[0018] Optionally, the determination of the current obstacle type of the obstacle when the snake robot contacts the obstacle includes:

[0019] acquiring, by the image acquisition device, an image of the head joint in the motion direction when the snake robot contacts the obstacle;

[0020] convert the image into an HSV space image, extract saturation of the HSV space image, and obtain a saturation value of each pixel in the HSV space image;

[0021] determine an average value and a standard deviation average value of saturation of the HSV space image according to the saturation value of each pixel;

[0022] determine the current obstacle type of the obstacle according to the average value and the standard deviation average value.

[0023] Optionally, the determination of the current obstacle type of the obstacle according to the average value and the standard deviation average value includes:

[0024] When both the average value and the standard deviation average value are smaller than corresponding preset thresholds, it is determined that the image is in a gray state;

[0025] When any value of the average value and the standard deviation average value is greater than the corresponding preset threshold value, it is determined that the image is in a bright state;

[0026] If the image is in the gray state, the current obstacle type is determined to be a convex type;

[0027] If the image is in the bright state, the current obstacle type is determined to be a concave type.

[0028] Optionally, the current obstacle type includes a convex type and a concave type; the determining the movement posture of the head joint according to the current obstacle type, comprising;

[0029] When the current obstacle type is the convex type, adjusting the movement posture of the head joint to a head-up movement;

[0030] When the current obstacle type is the concave type, the movement posture of the head joint is adjusted to a head-down movement.

[0031] Optionally, determining the inclination angle of the obstacle relative to the head joint according to the motion posture includes:

[0032] determining a contact posture between the head joint and the obstacle according to the movement posture of the head joint;

[0033] determining a vertical height of the pressure generating location from the ground based on the pressure generating location of the surface pressure;

[0034] The tilt angle is determined according to the vertical height.

[0035] Optionally, updating the normal gait curve according to the inclination angle to obtain an obstacle step curve includes:

[0036] By means of the inclination angle, the step height, step width and inclination degree of the obstacle are determined in sequence;

[0037] The normal gait curve is updated according to the step height, the step width and the inclination to obtain the obstacle step curve, wherein the obstacle step curve is a motion curve of the head joint on the obstacle.

[0038] Optionally, controlling each pitch joint of the snake-like robot to traverse the obstacle in sequence according to the obstacle step curve until the last pitch joint completes the obstacle traverse includes:

[0039] determine the joint angle of the snake robot when performing the normal traveling wave gait according to the phase difference between two adjacent pitch joints, the traveling wave amplitude of each pitch joint and the motion frequency;

[0040] determine the fitting joint angle required by each pitch joint when fitting the obstacle step curve according to the real-time position of each pitch joint on the obstacle step curve, in combination with the distance between adjacent pitch joints;

[0041] fit the obstacle step curve through the fitting joint angle, and control each pitch joint of the snake robot to perform obstacle climbing in turn until the last pitch joint completes fitting the obstacle step curve.

[0042] In a second aspect, the present application provides a robot autonomous obstacle climbing system, which is applied to a snake robot, the snake robot comprising a head joint and a plurality of pitch joints, the head joint and all the pitch joints being connected in turn, wherein the head joint is provided with a pressure sensing device and an image acquisition device.

[0043] The robot autonomous obstacle climbing system comprises:

[0044] a sensing unit, configured to determine whether the snake robot contacts an obstacle in the direction of travel through the pressure sensing device when the snake robot performs a normal traveling wave gait according to a normal gait curve;

[0045] a judging unit, configured to determine the current obstacle type of the obstacle through the image acquisition device when the snake robot contacts the obstacle;

[0046] a posture analysis unit, configured to determine the motion posture of the head joint according to the current obstacle type;

[0047] a calculating unit, configured to determine the inclination angle of the obstacle relative to the head joint according to the motion posture;

[0048] a curve updating unit, configured to update the normal gait curve to obtain an obstacle step curve according to the inclination angle;

[0049] a control unit, configured to control each pitch joint of the snake robot to perform obstacle climbing in turn until the last pitch joint completes obstacle climbing according to the obstacle step curve.

[0050] In a third aspect, the present application provides a computer readable storage medium, which stores a computer program, the computer program being executed by a processor to implement the robot autonomous obstacle climbing method described above.

[0051] The robot autonomous obstacle crossing method, system and storage medium of the present application significantly improve the movement effect of the snake-shaped robot when encountering obstacles by fusing pressure perception and visual information. First, the pressure sensing device arranged at the head joint is used to monitor whether the robot contacts the obstacle in real time. The instant sensing capability of the pressure sensing device facilitates the robot to react at the first time when encountering obstacles, avoiding collision or stagnation caused by delayed discovery of obstacles. Once the obstacle is detected, the type of the obstacle is determined by analyzing the image obtained by the image acquisition device. The type of the obstacle provides key information for the subsequent action of the robot. The movement posture of the head joint determined according to the type of the obstacle further helps the robot to adjust the posture to adapt to the shape of the obstacle, enhancing the adaptability of the robot to complex terrain. Subsequently, the inclination angle of the obstacle is determined and the normal gait curve is updated to the obstacle step curve, so that the robot can accurately adjust the action of each pitch joint behind the head joint according to the obstacle step curve, realizing smooth and efficient obstacle crossing action. In the whole process, the robot is no longer simply dependent on the preset gait mode, but can dynamically adjust its behavior according to the real-time perceived environmental information, thus showing more flexible, stable and efficient movement effect when encountering obstacles, effectively improving the autonomous obstacle crossing ability and movement efficiency of the snake-shaped robot in complex environment. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 Flowchart of the robot autonomous obstacle crossing method of the embodiment of the present application;

[0053] Figure 2 Structure schematic diagram of the snake-shaped robot of another embodiment of the present application;

[0054] Figure 3 Schematic diagram of the robot contacting the obstacle of another embodiment of the present application;

[0055] Figure 4 Schematic diagram of the robot contacting the obstacle of another embodiment of the present application;

[0056] Figure 5 Schematic diagram of the obstacle height detection in another embodiment of the present application;

[0057] Figure 6 Schematic diagram of the obstacle height detection in another embodiment of the present application;

[0058] Figure 7 Schematic diagram of the step width detection of the obstacle in another embodiment of the present application;

[0059] Figure 8 Structure schematic diagram of the robot autonomous obstacle crossing system in another embodiment of the present application. DETAILED DESCRIPTION

[0060] In order to make the above objectives, characteristics and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be construed as being limited to the embodiments set forth herein, but rather, these embodiments are provided so as to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are for illustrative purposes only, and are not intended to limit the scope of the present application.

[0061] It should be understood that each of the steps recited in the method embodiments of the present application can be performed in different orders, and / or in parallel. In addition, the method embodiments can include additional steps and / or omit the steps shown. The scope of the present application is not limited in this respect.

[0062] The term "comprising" and variations thereof as used herein are open-ended, that is, "comprising but not limited to"; the term "based on" is based at least in part on; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". Related definitions are given throughout the description. It should be noted that the concepts mentioned in the present application are merely used to distinguish different devices, modules or units, and are not intended to limit the functions performed by these devices, modules or units.

[0063] It should be noted that the modification of "one" or "multiple" mentioned in the present application is illustrative rather than limiting, and those skilled in the art should understand that, unless otherwise explicitly indicated in the context, it should be understood as "one or more".

[0064] The names of the messages or information exchanged between the devices in the embodiments of the present application are merely for illustrative purposes, and are not intended to limit the scope of the messages or information.

[0065] In combination Figure 1 As shown, the present application provides a robot autonomous obstacle crossing method, which is applied to a snake robot, the snake robot comprising a head joint and a plurality of pitch joints, the head joint and all the pitch joints being connected in turn, wherein the head joint is provided with a pressure sensing device and an image acquisition device.

[0066] Specifically, the snake robot comprises a head joint and a plurality of pitch joints, and in the preferred embodiments of the present application, in combination Figure 2As shown, the snake robot is divided into two parts of head and body, the bottom surface outside of the head joint of the robot is provided with a thin film pressure sensor and a monocular camera capable of observing the front, which are respectively used as a pressure sensing device and an image acquisition device.

[0067] The robot autonomous obstacle crossing method comprises the following steps:

[0068] When the snake robot is performing normal traveling wave gait according to the normal gait curve, the pressure sensing device is used to determine whether the snake robot contacts an obstacle in the direction of travel.

[0069] Specifically, when the snake robot is performing normal traveling wave gait, the pressure sensing device of the head joint is used to monitor in real time whether an obstacle is contacted. The pressure sensing device can sensitively detect the contact of the head with the obstacle, thereby providing a trigger signal for subsequent obstacle identification and obstacle crossing action. This instant perception capability enables the robot to react at the first time of encountering an obstacle, avoiding collision or stagnation caused by delayed discovery of the obstacle, and improving the safety and adaptability of the robot in complex environments. The head of the robot also comprises a wifi module for communication with the upper computer, which can transmit the head pressure data and the head camera image to the upper computer, and receive control instructions from the upper computer.

[0070] When the snake robot contacts the obstacle, the image acquisition device is used to determine the current obstacle type of the obstacle.

[0071] Specifically, when the snake robot detects the contact of the obstacle through the pressure sensing device, the image acquisition device is started immediately, and the type of the obstacle is determined by analyzing the image captured by the head camera. The obstacle is classified by using visual information, and accurate obstacle type identification is the key to effective obstacle crossing, because it determines the subsequent motion posture adjustment and obstacle crossing strategy of the robot. Therefore, in the preferred embodiment of the present application, the robot can quickly identify the characteristics of the obstacle by using image processing technology, thereby providing an accurate basis for subsequent obstacle crossing action, and enhancing the perception and identification ability of the robot for complex terrain.

[0072] According to the current obstacle type, the motion posture of the head joint is determined.

[0073] Specifically, according to the identified obstacle type, the robot determines the motion posture of the head joint, and by adjusting the posture of the head joint, the robot can better adapt to the shape of the obstacle and prepare for subsequent obstacle crossing action. For example, if it is a convex obstacle, the robot may raise the head; if it is a concave area, the robot may lower the head. This posture adjustment helps the robot to maintain stability when contacting the obstacle, reduces collision or jamming caused by improper posture, and improves the smoothness and reliability of the obstacle crossing process.

[0074] According to the motion posture, the inclination angle of the obstacle relative to the head joint is determined.

[0075] Specifically, after the head joint adjusts the posture, the inclination angle of the obstacle relative to the head joint is determined through the joint work of the pressure sensing device and the image acquisition device, which further refines the perception of the shape of the obstacle. The accurate measurement of the inclination angle enables the robot to adjust the motion trajectory of itself more accurately. By calculating the inclination angle, the robot can estimate the height and slope of the obstacle, so as to make more reasonable action adjustment in the process of obstacle crossing, ensuring that each pitch joint can smoothly pass through the obstacle, and improving the accuracy and success rate of obstacle crossing.

[0076] According to the inclination angle, the general gait curve is updated to obtain an obstacle step curve.

[0077] Specifically, according to the measured inclination angle, the robot updates the general gait curve to generate an obstacle step curve that adapts to the obstacle. This step is the core of the obstacle crossing action. By updating the gait curve, the robot can adjust the motion mode from the general traveling gait to the obstacle crossing gait that adapts to the obstacle. The generation of the obstacle step curve enables the robot to maintain a stable motion rhythm during obstacle crossing, and ensures that each pitch joint can move according to the predetermined trajectory, ensuring the continuity and coordination of the obstacle crossing action, and improving the stability and efficiency of obstacle crossing.

[0078] According to the obstacle step curve, each pitch joint of the snake-shaped robot is controlled to cross the obstacle in turn until the last pitch joint completes the obstacle crossing.

[0079] Specifically, finally, according to the updated obstacle step curve, the robot controls each pitch joint to cross the obstacle in turn until the last pitch joint completes the obstacle crossing. This step is the execution phase of the obstacle crossing action. By accurately controlling the motion of each pitch joint, the robot can gradually overcome the obstacle and achieve smooth obstacle crossing. The coordinated motion of each pitch joint ensures the overall stability of the robot during obstacle crossing, avoiding the imbalance or lag of the robot caused by improper action of a single joint.

[0080] The robot autonomous obstacle-crossing method of the present application significantly improves the movement effect of the snake-shaped robot when encountering obstacles by fusing pressure sensing and visual information. First, the pressure sensing device arranged at the head joint is used to monitor in real time whether the robot contacts the obstacle. The instant sensing capability of the pressure sensing device facilitates the robot to react at the first time when encountering obstacles, avoiding collision or stagnation caused by delayed detection of obstacles. Once the obstacle is detected, the type of the obstacle is determined by analyzing the image obtained by the image acquisition device. The type of the obstacle provides key information for the subsequent action of the robot. The movement posture of the head joint determined according to the type of the obstacle further helps the robot to adjust the posture to adapt to the shape of the obstacle, enhancing the adaptability of the robot to complex terrain. Subsequently, by determining the inclination angle of the obstacle and updating the general gait curve to the obstacle step curve, the robot can accurately adjust the action of each pitch joint behind the head joint according to the obstacle step curve, realizing smooth and efficient obstacle-crossing action. In the whole process, the robot no longer simply relies on the preset gait mode, but can dynamically adjust its behavior according to the real-time perceived environmental information, thus showing more flexible, stable and efficient movement effect when encountering obstacles, effectively improving the autonomous obstacle-crossing ability and movement efficiency of the snake-shaped robot in complex environment.

[0081] Optionally, the pressure sensing device is arranged on the contact surface of the head joint and the ground. The determination of whether the snake-shaped robot contacts the obstacle in the direction of movement by the pressure sensing device comprises:

[0082] The surface pressure of the head joint in the direction of movement is detected by the pressure sensing device. When the pressure pulse output by the pressure sensing device is acquired, it is determined that the surface has surface pressure. When the pressure pulse output by the pressure sensing device is not acquired, it is determined that the surface has no surface pressure.

[0083] When the surface has the surface pressure, it is determined that the snake-shaped robot does not contact the obstacle in the direction of movement.

[0084] When the surface has no surface pressure, it is determined that the snake-shaped robot contacts the obstacle in the direction of movement.

[0085] Specifically, in the snake-shaped robot autonomous obstacle-crossing method, the detection of the surface pressure of the head joint in the direction of movement by the pressure sensing device is one of the key steps to realize autonomous obstacle-crossing. In the preferred embodiment of the present application, the pressure sensing device is arranged on the contact surface of the head joint and the ground. Figure 3As shown, when the robot head encounters a convex obstacle, the head top end will be in contact with the slope of the obstacle, at which time the obstacle slope will give the robot a backward thrust, and the robot movement itself has a forward driving force, so that the robot keeps the head top end in contact with the obstacle slope, and the pressure sensor on the side of the head top end will always be higher than the ground, so that it is suspended and no longer detects the contact force with the ground, and thus determines that the robot head encounters the step of the obstacle. In combination Figure 3 As shown, when the robot head encounters a convex obstacle, the head top end will be in contact with the slope of the obstacle, at which time the obstacle slope will give the robot a backward thrust, and the robot movement itself has a forward driving force, so that the robot keeps the head top end in contact with the obstacle slope, and the pressure sensor on the side of the head top end will always be higher than the ground, so that it is suspended and no longer detects the contact force with the ground, and thus determines that the robot head encounters the step of the obstacle. In combination Figure 4 As shown, for the detection curve of the pressure pulse, the asterisk indicates the pressure pulse data generated when the pressure sensor no longer detects the contact with the ground, so as to determine that the robot head encounters the obstacle.

[0086] In the embodiment of the present application, through accurate pressure detection, the robot can perceive the existence of the obstacle at the first time, so as to timely adjust the movement posture and strategy, avoid the collision or stagnation caused by delayed discovery of the obstacle, not only enhance the adaptability and flexibility of the robot in complex terrain, but also significantly improve the safety and reliability of the obstacle crossing process, and reduce unnecessary time delay of the robot in the obstacle crossing process.

[0087] Optionally, when the snake-shaped robot contacts the obstacle, the current obstacle type of the obstacle is determined through the image acquisition device, including:

[0088] When the snake-shaped robot contacts the obstacle, the image of the head joint in the movement direction is acquired through the image acquisition device;

[0089] The image is converted into an HSV space image, and the saturation of the HSV space image is extracted to obtain the saturation value of each pixel in the HSV space image;

[0090] According to the saturation value of each pixel, the average value and the standard deviation average value of the saturation of the HSV space image are determined;

[0091] According to the average value and the standard deviation average value, the current obstacle type of the obstacle is determined.

[0092] Specifically, when the robot head contacts an obstacle, the image acquisition device acquires images of the head joint in the direction of movement. Subsequently, these images are converted into HSV (Hue-Saturation-Value) space images, and the saturation channel is extracted to obtain the saturation value of each pixel. By calculating the average and standard deviation of these saturation values, the characteristics of the image can be further analyzed. When the robot head contacts a convex obstacle, the image captured by the head camera appears dark and monotonous, with unsaturated colors, because the obstacle blocks the light. When a concave area is contacted, the image color appears normal. Therefore, by converting the camera image into HSV space and extracting the saturation S channel image for calculation, the type of obstacle can be determined. Specifically, if the average and standard deviation of the image saturation meet certain conditions (for example, the average is below a certain threshold, and the standard deviation is also below a certain threshold), it is considered that the image is in a dark state, i.e. the obstacle encountered in front is a convex obstacle; otherwise, it is a concave area. This process uses image processing techniques to analyze the color characteristics of the image to distinguish the type of obstacle, providing accurate basis for subsequent obstacle crossing actions.

[0093] In embodiments of the present application, by converting the image into HSV space and extracting the saturation information, the robot can quickly and accurately determine whether the obstacle is convex or concave. This image feature-based judgment method is not affected by changes in environmental light and has high robustness. After accurately identifying the type of obstacle, the robot can take appropriate obstacle crossing strategies, such as adjusting the movement posture of the head joint, to more effectively cross the obstacle.

[0094] Optionally, the determining the current obstacle type of the obstacle according to the average value and the standard deviation average value comprises:

[0095] When the average value and the standard deviation average value are both less than the corresponding preset threshold, it is determined that the image is in a dark state.

[0096] When any of the average value and the standard deviation average value is greater than the corresponding preset threshold, it is determined that the image is in a bright state.

[0097] If the image is in the dark state, the current obstacle type is determined to be a convex type.

[0098] If the image is in the bright state, the current obstacle type is determined to be a concave type.

[0099] Specifically, the obstacle type is determined by analyzing the mean and standard deviation of saturation in the HSV space of the image. When the robot head contacts a raised obstacle, the image captured by the head camera appears gray and monotonous, with unsaturated colors, due to the obstacle blocking light. In this case, both the mean and standard deviation of saturation are below a preset threshold (for example, the mean threshold Tμ is 20.0, and the standard deviation threshold Tσ is 15.0). Conversely, when the robot head contacts a recessed area, the image appears normal in color, with at least one of the mean and standard deviation of saturation exceeding the preset threshold. Therefore, by comparing these values ​​with the preset threshold, the image state can be accurately determined, ultimately determining whether the obstacle is raised or recessed. This process leverages statistical analysis methods in image processing technology, enabling rapid identification of obstacle types through simple threshold determination, providing an accurate basis for subsequent obstacle traversal. In a preferred embodiment of the present invention, when the robot's head contacts a raised obstacle or a recessed area, the head camera image will show a significant difference. If the obstacle is raised, the head camera will lack light input, resulting in a dull, monotonous, and unsaturated color. If the area is recessed, the head camera image will display normal color. Based on this, the camera image is converted to HSV space, and the saturation S channel image is extracted for calculation. The calculation formula for determining whether it is a raised obstacle is as follows:

[0100] ;

[0101] in, S i is the pixel value of the S channel, i Represents the pixel index, N is the total number of pixels, μ S and σ S are the mean and standard deviation of pixel saturation, T μ and T σ are the thresholds of the saturation mean and standard deviation, respectively. When the above formula is satisfied, the image is considered to be in a gray state, that is, the obstacle encountered in front of the robot is a convex obstacle, otherwise it is a concave area.

[0102] In this embodiment of the present invention, by setting a clear threshold, the robot can quickly distinguish between dark and bright states in an image, thereby accurately determining the type of obstacle. This method is not only simple and efficient, but also highly robust to changes in ambient light, and can operate stably under various lighting conditions.

[0103] Optionally, the current obstacle type includes a convex type and a concave type; the determining the movement posture of the head joint according to the current obstacle type, comprising;

[0104] adjusting the motion posture of the head joint as a head-lowering motion when the current obstacle type is the recessed type.

[0105] adjusting the motion posture of the head joint as a head-lowering motion when the current obstacle type is the recessed type.

[0106] Specifically, when the current obstacle type is identified as the protruding type, the robot adjusts the motion posture of the head joint as a head-raising motion; conversely, when the current obstacle type is identified as the recessed type, the robot adjusts the motion posture of the head joint as a head-lowering motion. This adjustment is based on the physical characteristics of the obstacles: protruding obstacles require the robot to raise its head to avoid collision and smoothly climb, while recessed areas require the robot to lower its head to ensure a smooth transition. This motion posture adjustment based on obstacle type enables the robot to adapt more flexibly to different types of obstacles, improving the success rate and efficiency of obstacle crossing.

[0107] In embodiments of the present application, by adjusting the motion posture of the head joint according to the obstacle type, the robot can more accurately respond to different types of obstacles, reducing collisions or stalls caused by improper posture. This flexible adjustment mechanism not only improves the autonomy and flexibility of the robot, but also significantly improves the reliability and practicality of the robot in actual applications.

[0108] Optionally, determining the inclination angle of the obstacle relative to the head joint according to the motion posture comprises:

[0109] determining the contact posture of the head joint with the obstacle according to the motion posture of the head joint;

[0110] determining the vertical height of the pressure-generating position from the ground according to the pressure-generating position of the surface pressure;

[0111] determining the inclination angle according to the vertical height.

[0112] Specifically, first, the contact posture of the head joint with the obstacle is determined according to the motion posture of the head joint (looking up or looking down). Then, the vertical height of the position where the pressure is generated from the ground is determined by the pressure sensing device. Finally, the inclination angle of the obstacle is calculated using the vertical height. When the robot head contacts the convex obstacle and performs the looking-up motion, the head joint contacts the slope of the obstacle, and the pressure sensor detects a pressure pulse. By analyzing the position of the pressure pulse and the posture of the head joint, the vertical height of the position where the pressure is generated from the ground can be determined. Using the trigonometric relationship, combined with the vertical height and the motion parameters of the head joint, the inclination angle of the obstacle is calculated. This process not only relies on the accurate data of the pressure sensor, but also combines the motion posture of the head joint, so that the robot can accurately perceive the inclination degree of the obstacle, providing key parameters for subsequent obstacle crossing actions.

[0113] In the embodiments of the present application, by accurately determining the inclination angle of the obstacle, the robot can more accurately adjust its motion trajectory, ensuring that each pitch joint can smoothly pass through the obstacle. This accurate perception and adjustment mechanism not only reduces the collision or jam caused by improper posture, but also improves the continuity and coordination of the obstacle crossing process.

[0114] Optionally, the updating of the normal gait curve according to the inclination angle to obtain an obstacle step curve comprises:

[0115] The step height, step width and inclination degree of the obstacle are sequentially determined according to the inclination angle;

[0116] The normal gait curve is updated according to the step height, step width and inclination degree to obtain the obstacle step curve, wherein the obstacle step curve is a motion curve of the head joint on the obstacle.

[0117] Specifically, first, the step height, step width and inclination degree of the obstacle are sequentially determined using the inclination angle determined before. These parameters are obtained by analyzing the pressure sensor data and the motion posture of the head joint. When the robot head contacts the obstacle and determines the inclination angle, the step height and width of the obstacle can be calculated by the position of the pressure pulse detected by the pressure sensor and the motion posture of the head joint. For example, when the robot head passes over the vertex of the slope of the obstacle, the head pressure sensor will be suspended again, and at this time the height of the obstacle can be determined. By these parameters, combined with the theory of planar step curve, the normal gait curve is updated to generate an obstacle step curve that adapts to the obstacle. The obstacle step curve describes the motion trajectory of the head joint on the obstacle, so that the robot can smoothly cross the obstacle according to the predetermined trajectory. Combined with the inclination angle of the obstacle, the robot can adjust its motion trajectory more accurately, ensuring that each pitch joint can smoothly pass through the obstacle. This accurate perception and adjustment mechanism not only reduces the collision or jam caused by improper posture, but also improves the continuity and coordination of the obstacle crossing process. Figure 5As shown in the figure, if the snake-like robot is crawling and climbing a raised obstacle slope, the pressure sensor on the robot's head will continuously contact the obstacle slope, thereby detecting pressure pulses. This state will continue until the head passes the top of the obstacle slope. At this time, the head pressure sensor will be suspended again, thereby realizing the height detection of the obstacle. Figure 6 As shown in the figure, if the snake-like robot is crawling up a slope in a sunken area, after detecting the slope's inclination angle, the head joint module is kept in horizontal motion, so that the head pressure sensor remains suspended. The body joint behind the head joint is continuously fitted into the sunken slope until the head pressure sensor contacts the ground and generates a pressure pulse. The measured obstacle height at this point is the height of the sunken area.

[0118] In a preferred embodiment of the present invention, the standard gait curve is updated based on step height, step width, and inclination. Each obstacle's raised or recessed portion is abstracted as a step curve. The step curve is a piecewise function. The first half of the function is a one-dimensional Gaussian function, describing the inclination of the obstacle edge. The second half of the function is a constant, representing the platform height of the obstacle or recessed step. The step curve's piecewise function uses 3.717σ as the segmentation point. This is because for a Gaussian function, the height decays to 0.1% of its maximum value at a distance of 3.717σ from the peak along the x-axis. This error is negligible when the robot is fitting the curve.

[0119] Since the shape of the obstacle is irregular, the shape between the obstacle and the ground can be abstracted into multiple step curves using the above method, so that the entire obstacle step curve is composed of multiple single step curves. The parametric equation of a single step curve is:

[0120] ;

[0121] Where x is the displacement along the direction of robot movement, z is the height from the ground, h is the step height, w is the step width, σ is the inclination of the step, and e is a constant.

[0122] For the obstacle step curve of a combination of multiple steps, the following formula can be used to accumulate it:

[0123] ;

[0124] in, h n,last For the front n The height of the combined steps is x n,last is the length of the first n steps in the x-axis direction, h n 、 w n 、σ n are the height, width, and inclination of the nth step respectively.

[0125] For the n The slope of each step is affected by σ n and h n The combined influence of the two factors is used to estimate the inclination angle using trigonometric calculations. Considering the width of the step at the inclination is 3.717 σ n , tilt angle θ n The calculation formula is as follows:

[0126] ;

[0127] in, h n is the height of the nth step, σ n is the inclination of the nth step.

[0128] In another preferred embodiment of the present invention, the head pressure sensor is still used to constantly detect whether the head touches a new obstacle. When the head touches a new obstacle step, it is determined that the head has completed the step of the previous obstacle, and the distance from the top of the previous obstacle step to the starting point of the new obstacle is used as the width of the previous obstacle step, so that subsequent joints follow the movement of the head joint. Figure 7 As shown in the figure, when the snake robot head detects a new obstacle step, the width of the current obstacle step can be calculated. Assuming that the new obstacle step is the n+1th step, the calculation formula for the current step width is as follows:

[0129] ;

[0130] in, x n,last is the length of the first n steps in the x-axis direction, x n-1,last is the length of the first n-1 steps in the x-axis direction.

[0131] In an embodiment of the present invention, by accurately updating the gait curve, the robot can generate a motion trajectory that adapts to the specific shape of the obstacle, ensuring that each pitch joint can pass through the obstacle smoothly. This not only improves the continuity and coordination of the obstacle crossing process, but also reduces collisions or jams caused by improper posture, thereby improving the success rate and efficiency of obstacle crossing.

[0132] Optionally, the control of each of the pitch joints of the snake robot to sequentially climb the obstacle according to the obstacle step curve until the last pitch joint completes the obstacle climbing comprises:

[0133] According to the phase difference between the adjacent two pitch joints, the traveling wave amplitude of each pitch joint and the motion frequency, the joint angle of the snake robot when performing the normal traveling wave gait is determined;

[0134] According to the real-time position of each pitch joint on the obstacle step curve, in combination with the distance between the adjacent pitch joints, the fitting joint angle required by each pitch joint when fitting the obstacle step curve is determined;

[0135] The obstacle step curve is fitted by the fitting joint angle, and each of the pitch joints of the snake robot is controlled to sequentially climb the obstacle until the last pitch joint completes the fitting of the obstacle step curve.

[0136] Specifically, first, according to the phase difference between the adjacent two pitch joints, the traveling wave amplitude of each pitch joint and the motion frequency, the joint angle of the snake robot when performing the normal traveling wave gait is determined. These parameters are the basic parameters of the normal motion of the snake robot, which ensures that the robot can smoothly advance according to the predetermined gait curve. Then, according to the real-time position of each pitch joint on the obstacle step curve, in combination with the distance between the adjacent pitch joints, the fitting joint angle required by each pitch joint when fitting the obstacle step curve is determined. Therefore, dynamic fitting of the obstacle step curve is required to ensure that each joint can accurately adapt to the shape of the obstacle. When the head of the robot determines the step height, width and inclination of the obstacle, the normal gait curve is updated by these parameters to generate the obstacle step curve. Then, the real-time data of the head pressure sensor and the image acquisition device are used to dynamically adjust the angle of each pitch joint, so that it can smoothly pass through the obstacle. For example, when the head of the robot passes over the vertex of the slope of the obstacle, the subsequent pitch joints will gradually adjust the angle according to the obstacle step curve, and climb the obstacle one by one until the last pitch joint completes the obstacle climbing.

[0137] In the preferred embodiment of the present application, the multi-joint robot can perform two-dimensional morphological fitting on the step curve, and the i-th pitch joint angle of the robot is:

[0138] ;

[0139] Where s represents the arc length of the step curve starting from x=0, p(s) represents the curvature of the curve, m represents the distance between the two pitch joints, represents the position of the i-th pitch joint on the step curve, so indicates the joint angle required for the robot to fit the step curve; indicates the joint angle required for the robot to perform the normal traveling wave gait, wherein A indicates the traveling wave amplitude, is the motion frequency, indicates the phase difference between two adjacent joint angles. Through superposition, it can ensure that the robot realizes stable forward movement on the basis of fitting the step curve.

[0140] In the embodiment of the present application, by precisely controlling the angle of each pitch joint, the robot can generate a motion trajectory that adapts to the specific shape of the obstacle, ensuring that each pitch joint can smoothly pass through the obstacle. Especially in the face of complex terrain and variable obstacles, this dynamic adjustment mechanism not only improves the continuity and coordination of the obstacle crossing process, but also reduces the collision or jam caused by improper posture, improves the success rate and efficiency of obstacle crossing.

[0141] In combination Figure 8 As shown, the present application also provides a robot autonomous obstacle crossing system, which is applied to a snake-shaped robot, the snake-shaped robot comprising a head joint and a plurality of pitch joints, the head joint and all the pitch joints being connected in turn, wherein the head joint is provided with a pressure sensing device and an image acquisition device;

[0142] The robot autonomous obstacle crossing system comprises:

[0143] A sensing unit is configured to determine whether the snake-shaped robot contacts an obstacle in the direction of travel through the pressure sensing device when the snake-shaped robot performs a normal traveling wave gait according to a normal gait curve;

[0144] A judging unit is configured to determine the current obstacle type of the obstacle through the image acquisition device when the snake-shaped robot contacts the obstacle;

[0145] A posture analysis unit is configured to determine the motion posture of the head joint according to the current obstacle type;

[0146] A calculation unit is configured to determine the inclination angle of the obstacle relative to the head joint according to the motion posture;

[0147] A curve updating unit is configured to update the normal gait curve according to the inclination angle to obtain an obstacle step curve;

[0148] A control unit is configured to control each pitch joint of the snake-shaped robot to cross the obstacle in turn according to the obstacle step curve until the last pitch joint completes the obstacle crossing.

[0149] The robot autonomous obstacle-crossing system of the present application significantly improves the movement effect of the snake-shaped robot when encountering obstacles by fusing pressure sensing and visual information. Firstly, the pressure sensing device arranged at the head joint is used to monitor in real time whether the robot contacts the obstacle. The instant sensing capability of the pressure sensing device facilitates the robot to respond at the first time when encountering the obstacle, avoiding collision or stagnation caused by delayed discovery of the obstacle. Once the obstacle is detected, the type of the obstacle is determined by analyzing the image obtained by the image acquisition device. The type of the obstacle provides key information for the subsequent action of the robot. The movement posture of the head joint determined according to the type of the obstacle further helps the robot to adjust the posture to adapt to the shape of the obstacle, enhancing the adaptability of the robot to complex terrain. Subsequently, the inclination angle of the obstacle is determined and the normal gait curve is updated to the obstacle step curve, so that the robot can accurately adjust the action of each pitch joint behind the head joint according to the obstacle step curve, realizing smooth and efficient obstacle-crossing action. In the whole process, the robot no longer simply relies on the preset gait mode, but can dynamically adjust its behavior according to the real-time perceived environmental information, thereby exhibiting more flexible, stable and efficient movement effect when encountering obstacles, effectively improving the autonomous obstacle-crossing ability and movement efficiency of the snake-shaped robot in complex environment.

[0150] The embodiment of the present application provides a computer readable storage medium, and the storage medium stores a computer program. When the computer program is executed by a processor, the robot autonomous obstacle-crossing method is realized.

[0151] Alternatively, a non-volatile computer readable storage medium stores a computer program. When the computer program is executed by a processor, the processor executes the following operations:

[0152] When the snake-shaped robot performs normal traveling wave gait according to the normal gait curve, whether the snake-shaped robot contacts the obstacle in the traveling direction is determined by the pressure sensing device;

[0153] When the snake-shaped robot contacts the obstacle, the current obstacle type of the obstacle is determined by the image acquisition device;

[0154] According to the current obstacle type, the movement posture of the head joint is determined;

[0155] According to the movement posture, the inclination angle of the obstacle relative to the head joint is determined;

[0156] According to the inclination angle, the normal gait curve is updated to obtain the obstacle step curve;

[0157] According to the obstacle step curve, each pitch joint of the snake robot is controlled to successively perform obstacle crossing until the last pitch joint completes obstacle crossing.

[0158] The computer readable storage medium of the present application significantly improves the movement effect of the snake robot when encountering obstacles by fusing pressure sensing and visual information. Firstly, the pressure sensing device arranged at the head joint is used to monitor whether the robot contacts the obstacle in real time. The instant sensing capability of the pressure sensing device facilitates the robot to make a response at the first time when encountering obstacles, avoiding collision or stagnation caused by delayed discovery of obstacles. Once the obstacle is detected, the type of the obstacle is determined by analyzing the image obtained by the image acquisition device. The type of the obstacle provides key information for the subsequent action of the robot. The movement posture of the head joint determined according to the type of the obstacle further helps the robot to adjust the posture to adapt to the shape of the obstacle, enhancing the adaptability of the robot to complex terrain. Subsequently, the inclination angle of the obstacle is determined and the normal gait curve is updated to the obstacle step curve, so that the robot can accurately adjust the action of each pitch joint behind the head joint according to the obstacle step curve, realizing smooth and efficient obstacle crossing action. In the whole process, the robot no longer simply relies on the preset gait mode, but can dynamically adjust its behavior according to the real-time perceived environmental information, thus showing more flexible, stable and efficient movement effect when encountering obstacles, effectively improving the autonomous obstacle crossing ability and movement efficiency of the snake robot in complex environment.

[0159] Although the present application has been disclosed as above, the protection scope of the present application is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and these changes and modifications will fall within the protection scope of the present application.

Claims

1. A robot autonomous obstacle crossing method, characterized in that: The method is applied to a snake-like robot, which includes a head joint and a plurality of pitch joints, wherein the head joint and all the pitch joints are connected in sequence, wherein the head joint is provided with a pressure sensing device and an image acquisition device; The robot autonomous obstacle crossing method comprises: When the snake-like robot performs a normal traveling wave gait according to a normal gait curve, the pressure sensing device is used to determine whether the snake-like robot contacts an obstacle in the direction of travel; When the snake-like robot contacts the obstacle, determining the current obstacle type of the obstacle through the image acquisition device; determining a movement posture of the head joint according to the current obstacle type; determining, based on the motion posture, an inclination angle of the obstacle relative to the head joint; Updating the normal gait curve according to the inclination angle to obtain an obstacle step curve, wherein the method specifically includes: sequentially determining the step height, step width, and inclination degree of the obstacle according to the inclination angle; updating the normal gait curve according to the step height, step width, and inclination degree to obtain the obstacle step curve, wherein the obstacle step curve is a motion curve of the head joint on the obstacle; According to the obstacle step curve, each pitch joint of the snake-like robot is controlled to traverse obstacles in sequence until the last pitch joint completes the obstacle traverse, which specifically includes: determining the joint angle of the snake-like robot when performing a normal traveling wave gait according to the phase difference between two adjacent pitch joints and the traveling wave amplitude and movement frequency of each pitch joint; determining the fitting joint angle required for each pitch joint when fitting the obstacle step curve according to the real-time position of each pitch joint on the obstacle step curve and the spacing between adjacent pitch joints; fitting the obstacle step curve through the fitting joint angle, and controlling each pitch joint of the snake-like robot to traverse obstacles in sequence until the last pitch joint completes fitting the obstacle step curve.

2. The robot autonomous obstacle traversal method according to claim 1, characterized in that: The pressure sensing device is provided on the contact surface between the head joint and the ground, and judging whether the snake-like robot contacts an obstacle in the direction of travel by using the pressure sensing device includes: The pressure on the surface of the head joint in the direction of movement is detected by the pressure sensing device; when a pressure pulse output by the pressure sensing device is obtained, it is determined that surface pressure exists on the surface; when no pressure pulse output by the pressure sensing device is obtained, it is determined that no surface pressure exists on the surface; When the surface pressure exists on the surface, determining that the snake-like robot does not contact the obstacle in the moving direction; When the surface pressure does not exist on the surface, it is determined that the snake-like robot has contacted the obstacle in the moving direction.

3. The robot autonomous obstacle traversal method according to claim 1, characterized in that: When the snake-like robot contacts the obstacle, determining the current obstacle type of the obstacle by the image acquisition device includes: When the snake-like robot contacts the obstacle, the image of the head joint in the movement direction is acquired by the image acquisition device; Converting the image into an HSV spatial image, and performing saturation extraction on the HSV spatial image to obtain a saturation value of each pixel in the HSV spatial image; Determine the average value and the average standard deviation of the saturation of the HSV spatial image according to the saturation value of each pixel; A current obstacle type of the obstacle is determined according to the average value and the average value of the standard deviation.

4. The robot autonomous obstacle traversal method according to claim 3, characterized in that: The determining, based on the average value and the average value of the standard deviation, the current obstacle type of the obstacle includes: When both the average value and the standard deviation average value are smaller than corresponding preset thresholds, it is determined that the image is in a gray state; When any value of the average value and the standard deviation average value is greater than the corresponding preset threshold value, it is determined that the image is in a bright state; If the image is in the gray state, the current obstacle type is determined to be a convex type; If the image is in the bright state, the current obstacle type is determined to be a concave type.

5. The robot autonomous obstacle traversal method according to claim 1, characterized in that: The current obstacle type includes a convex type and a concave type; and determining the movement posture of the head joint according to the current obstacle type includes: When the current obstacle type is the convex type, adjusting the movement posture of the head joint to a head-up movement; When the current obstacle type is the concave type, the movement posture of the head joint is adjusted to a head-down movement.

6. The robot autonomous obstacle traversal method according to claim 2, characterized in that: Determining the inclination angle of the obstacle relative to the head joint according to the motion posture includes: determining a contact posture between the head joint and the obstacle according to the movement posture of the head joint; determining a vertical height of the pressure generating location from the ground based on the pressure generating location of the surface pressure; The tilt angle is determined according to the vertical height.

7. A robot autonomous obstacle crossing system, characterized in that: The system is applied to a snake-like robot, which includes a head joint and a plurality of pitch joints, wherein the head joint and all the pitch joints are connected in sequence, wherein the head joint is provided with a pressure sensing device and an image acquisition device; The robot autonomous obstacle crossing system includes: a sensing unit, configured to determine, by means of the pressure sensing device, whether the snake-like robot contacts an obstacle in its traveling direction when the snake-like robot performs a normal traveling wave gait according to a normal gait curve; a judgment unit, configured to determine a current obstacle type of the obstacle through the image acquisition device when the snake-like robot contacts the obstacle; a posture analysis unit, configured to determine a movement posture of the head joint according to the current obstacle type; a calculation unit, configured to determine an inclination angle of the obstacle relative to the head joint according to the motion posture; a curve updating unit, configured to update the normal gait curve according to the inclination angle to obtain an obstacle step curve, wherein the updating unit specifically includes: sequentially determining the step height, step width, and inclination degree of the obstacle according to the inclination angle; and updating the normal gait curve according to the step height, step width, and inclination degree to obtain the obstacle step curve, wherein the obstacle step curve is a motion curve of the head joint on the obstacle; A control unit is used to control each pitch joint of the snake-like robot to traverse obstacles in sequence according to the obstacle step curve until the last pitch joint completes the obstacle traverse, which specifically includes: determining the joint angle of the snake-like robot when performing a normal traveling wave gait according to the phase difference between two adjacent pitch joints and the traveling wave amplitude and movement frequency of each pitch joint; determining the fitting joint angle required for each pitch joint when fitting the obstacle step curve according to the real-time position of each pitch joint on the obstacle step curve and the spacing between adjacent pitch joints; fitting the obstacle step curve by using the fitting joint angle, and controlling each pitch joint of the snake-like robot to traverse obstacles in sequence until the last pitch joint completes fitting the obstacle step curve.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the robot autonomous obstacle surmounting method according to any one of claims 1 to 6 is implemented.

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