A crawling gait planning method for a multi-legged robot

Abstract

A kind of multi-branch robot's crawling gait planning method, it is related to mechanical arm motion control and planning field.The three-branch robot is configured, according to the situation, pre-planning arrangement is arranged on the path, limit to two step lengths, according to two step lengths, define the preset angle corresponding to each pitch joint in the state of grabbing, solve in advance by inverse kinematics, according to the step length of the first step, the bottom two mechanical arms hold the first two grab points, the top mechanical arm is idle, combined with visual identification system, judge whether there is yaw angle and next step length, execute crawling scheme planning, repeat execution until the final point, release the last second grab point, all joints move to zero position.Cover equidistant crawling, non-equidistant crawling, turning crawling, sharp turning crawling four typical application scenarios, through the standardized mechanical arm coordinated motion control, reduce the control complexity of multi-branch robot, improve the crawling motion efficiency and scene adaptability.

Description

Technical Field

[0001] This invention relates to the field of motion control and planning technology for robotic arms, specifically a crawling gait planning method for multi-branch robots. Background Technology

[0002] For on-orbit service robots, planning the high-speed, orderly movement of each robotic arm joint is a prerequisite for the robot to quickly and efficiently complete its work objectives. Reasonably planning the robotic arm's movement to enable the robot to crawl to its work position in a coordinated, rapid, wide-range, and standardized gait is an important research area. For example, Chinese invention patent application CN121589835A discloses a crawling gait planning method for a crawlable robotic arm. Its technical solution, targeting a single seven-degree-of-freedom redundant robotic arm, details the technical aspects of achieving an alternating crawling gait at both ends, enabling the robotic arm to achieve wide-range, rapid movement.

[0003] Currently, most existing space robot motion planning focuses on the case where a single robotic arm performs crawling functions, while there is relatively little research on the case where robots composed of multiple robotic arms, i.e., multi-branch robots, perform crawling tasks.

[0004] Compared to single-arm robots, multi-branch robots have significantly increased degrees of freedom, making them prone to redundant structures and significantly increasing system complexity and control difficulty, thus requiring a simple and stable control planning method. Furthermore, while some research exists on crawling gait in existing crawling multi-branch robots, a standardized and normalized set of gait patterns and movement sequences has not yet been established, and planning methods and motion efficiency still need further improvement. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a crawling gait planning method for multi-branch robots, covering four typical application scenarios: equidistant crawling, non-equidistant crawling, turning crawling, and sharp-turn crawling. Through standardized coordinated motion control of the robotic arm, the control complexity of multi-branch robots is reduced, and crawling efficiency and scenario adaptability are improved.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a crawling gait planning method for a multi-branch robot, comprising the following steps:

[0007] Step S1, Initial Robot Configuration: Configure a three-branch robot with three symmetrical seven-degree-of-freedom robotic arms evenly arranged circumferentially along the edge of the robot's body. The seven joints of each robotic arm are all rotational joints, and the rolling and pitching are alternately arranged from the connecting end of the robotic arm to the free end. Among them, joints 1, 3, 5, and 7 are rolling degrees of freedom, and joints 2, 4, and 6 are pitching degrees of freedom. In the zero position, the center points of the seven joints are on the same straight line, and all pitch joints are parallel to each other. The free end of the robotic arm is equipped with a gripping tool for gripping the gripping point on the crawling path. In the initial state, the three-branch robot is evenly arranged in a Y shape.

[0008] Step S2, Pre-crawling path planning: Based on the starting and ending points of the actual crawling path, pre-plan the layout along the path. There are several gripping points, and their placement is restricted so that the distance between any two adjacent gripping points is only divided into preset steps. and spare step size Two kinds, The yaw angle is set between adjacent steps according to the requirements, and the grab points are numbered according to the crawling sequence. Determine the step length for each step during the crawling process. and direction;

[0009] Step S3, Robot state definition before crawling: Based on the preset step size and spare step size Define a set of preset joint angles for each pitch joint under two adjacent gripping point gripping states, denoted as preset angle one and preset angle two, and solve the joint angles of each pitch joint in advance through inverse kinematics;

[0010] Step S4: Crawling Scheme Determination: The bottom single robotic arm of the three-branch robot configured in Step S1 grasps the starting point of the crawling path laid out in Step S2. First, based on the step length of the first step, the pitch joints of the robot's three robotic arms are moved to the corresponding angle positions, so that the two robotic arms at the bottom of the robot grasp the first two grasping points respectively, while the robotic arm at the top of the robot remains idle. Then, the crawling scheme is planned using the visual recognition system: it is determined whether there is a yaw angle in the next step. If there is no yaw angle, the step length for the next step is determined, and the step length is the preset step length. Perform equidistant crawling movements, with the step size being the spare step size. Perform non-equidistant crawling maneuvers; if a yaw angle exists. Then determine the magnitude of the yaw angle. When performing a turning and crawling maneuver, Perform a sharp turn and crawl maneuver at the same time;

[0011] Step S5, Crawling Task Termination: After each grasping point, determine whether the next grasping point is the final point. If it is not the final point, continue to execute the crawling plan in step S4. If it is the final point, first release the second to last grasping point, and then move all joints of the robot's three robotic arms to the zero position to end the crawling task.

[0012] Furthermore, the preset angle corresponds to a step size. In the equidistant crawling scenario, when two robotic arms of the three-branch robot respectively grasp two adjacent grasping points, and the third robotic arm does not grasp any grasping points: the joint angles of joints 2, 4, and 6 of the robotic arm that grasps the larger grasping point are respectively... , , The robotic arm that grasps the smaller grasping point has joint angles of joints 2, 4, and 6 as follows: , , ,and For the robotic arm that did not grasp the gripping point, the joint angles of joints 2, 4, and 6 are respectively... , , .

[0013] Furthermore, the preset angle two corresponds to the step size. In the non-equidistant crawling scenario, the joint angles of joints 2, 4, and 6 of the robotic arm that grasps the smaller-numbered grasping point and the robotic arm that does not grasp any grasping points are the same as the preset angle 1. For the robotic arm that grasps the larger-numbered grasping point, the joint angles of joints 2, 4, and 6 are respectively... , , ,and .

[0014] Furthermore, the specific steps of the equidistant crawling action are as follows:

[0015] (1) The robotic arm that gripped the smaller gripping point releases, and the robotic arm that gripped the larger gripping point becomes the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation.

[0016] (2) Rotate joints 2, 4 and 6 of the three robotic arms synchronously so that the joint angles of each robotic arm reach the angle positions corresponding to the preset angle.

[0017] (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

[0018] Furthermore, the specific steps of the non-equidistant crawling action are as follows:

[0019] (1) The robotic arm that gripped the smaller gripping point releases, and the robotic arm that gripped the larger gripping point becomes the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation.

[0020] (2) Rotate joints 2, 4 and 6 of the three robotic arms synchronously so that the joint angles of each robotic arm reach the angle positions corresponding to the preset angle 2.

[0021] (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

[0022] Furthermore, the specific steps of the turning and crawling action are as follows:

[0023] (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point.

[0024] (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso deflects and aligns with the elevation plane containing the line connecting the current gripping point and the next gripping point;

[0025] (3) The robotic arm that grasps the current grasping point is used as the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation.

[0026] (4) The next step size is the preset step size. Or a spare step size Simultaneously rotate joints 2, 4, and 6 of the three robotic arms to the angle position corresponding to preset angle one or preset angle two;

[0027] (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

[0028] Furthermore, the specific steps of the sharp turn crawling maneuver are as follows:

[0029] (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point.

[0030] (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso is tilted and positioned on the vertical plane where the line connecting the current gripping point and the next gripping point is located, thus completing the change of the robotic arm's gripping role.

[0031] (3) Modify the corresponding parameters of preset angle one and preset angle two to adapt to the gripping role of the robotic arm after turning. When the number of sharp turn crawls is even, the modified preset angle one and modified preset angle two are consistent with the original preset angle one and original preset angle two. When the number of sharp turn crawls is odd, the modified preset angle one and modified preset angle two change as follows:

[0032] Modified preset angle 1: For the robotic arm grasping the smaller grasping point, the angles of joints 2, 4, and 6 are respectively... , , For the robotic arm that grasps the larger grasping point and the robotic arm that does not grasp the grasping point, joints 2, 4, and 6 are respectively , , ;

[0033] Modified preset angle two: For the robotic arm grasping the smaller grasping point, the angles of joints 2, 4, and 6 are respectively , , For the robotic arm that grasps the larger grasping point and the robotic arm that does not grasp the grasping point, joints 2, 4, and 6 are respectively , , ;

[0034] (4) The next step size is the preset step size. Or a spare step size Simultaneously rotate joints 2, 4, and 6 of the three robotic arms to the angle positions corresponding to the modified preset angle one or preset angle two;

[0035] (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] 1. The method of this invention takes into account the situation of a multi-branch robot in space performing a crawling task under the coordinated movement of each robotic arm. By limiting the number and range of motion of the controlled joints, the difficulty of solving the joint angles and the difficulty of control are reduced. At the same time, by simplifying the movement mode of the robot during crawling, the robot can move more efficiently on a track with a specific step length while ensuring that the robot completes the crawling task. Furthermore, the method appropriately adjusts the corresponding robotic arm motion plan for situations where non-equidistant step lengths or yaw occurs during movement. It is highly adaptable to different scenarios and can quickly and efficiently reach the target point, thereby improving work efficiency.

[0038] 2. The method of the present invention provides a standardized solution for the crawling motion of multi-branch robots in space. Based on pre-set path grasping points, robotic arm motion modes and judgment algorithms, it is easy to deploy and implement in practical engineering applications, and the corresponding parameters can be flexibly modified and the planned gait can be adjusted according to actual conditions. Attached Figure Description

[0039] Figure 1 This is a flowchart of the method of the present invention;

[0040] Figure 2 This is a schematic diagram illustrating the composition of a three-branch robot according to an example of the present invention;

[0041] Figure 3 This is a schematic diagram illustrating the degrees of freedom of a single robotic arm in this invention;

[0042] Figure 4 This is a schematic diagram of the gait nodes of the robot in the equidistant crawling situation from a horizontal perspective in this invention;

[0043] Figure 5 This is a schematic diagram of the robot's gait nodes under non-equidistant crawling conditions from a horizontal perspective in this invention;

[0044] Figure 6 This is a schematic diagram of the robot's gait nodes in a turning and crawling situation from an overhead view in this invention;

[0045] Figure 7 This is a schematic diagram of the robot's gait nodes in a sharp turn crawling situation from an overhead view in this invention. Detailed Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0047] To address the technical challenges of coordinated, rapid, wide-range, and standardized gait crawling motion in robotic arms, this invention discloses a crawling gait planning method for multi-branch robots. This embodiment uses a three-branch robot composed of three identical seven-degree-of-freedom robotic arms as an example to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention, nor is it intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0048] Robot structure description:

[0049] The multi-branch robot structure combination targeted by this invention Figure 2 As shown, the robot torso controls three robotic arms. It adopts a rotationally symmetrical base structure, with three gripping points evenly distributed circumferentially along its edge. The three robotic arms, with identical configuration and parameters, are initially connected to the robot torso at equal angles. Simultaneously, the robot torso is equipped with a vision recognition system for identifying the yaw angle and step length of subsequent grasping steps along the path during the crawling task.

[0050] The structural combination of a single robotic arm Figure 3 As shown, this is a symmetrical seven-DOF robotic arm. All seven joints are rotary joints with roll or pitch degrees of freedom. Roll and pitch are alternately arranged from the connecting end towards the free end. The center points of the seven joints are on the same straight line when in the zero position. Joints 1, 3, 5, and 7 have roll degrees of freedom, while joints 2, 4, and 6 have pitch degrees of freedom. Simultaneously, gripping tools are installed at both ends of the robotic arm. The gripping tool at the connecting end is used to grasp gripping points on the torso, while the gripping tool at the free end is used to grasp gripping points along the crawling path during subsequent crawling.

[0051] Robot crawling gait planning:

[0052] The method of this invention covers four typical application scenarios: equidistant crawling, non-equidistant crawling, turning crawling, and sharp-turn crawling. Its overall process combines... Figure 1 As shown, the specific steps are as follows:

[0053] Step S1, Initial Robot Configuration:

[0054] Configure a three-branch robot so that all pitch joints (joint 2, joint 4, joint 6) of each robotic arm are parallel to each other, and all joints of all robotic arms are in the zero position. In the initial state, the three-branch robot is evenly arranged in a Y shape.

[0055] Step S2, Path planning before crawling:

[0056] Based on the actual starting and ending points of the crawling path, the layout is planned and arranged in advance as needed along the path. There are several gripping points, and their placement is restricted so that the distance between any two adjacent gripping points is only divided into preset steps. and spare step size Two scenarios, The yaw angle can be set between adjacent steps as needed, and the grab points are numbered according to the crawling sequence. Then grab the point Starting point, grab point The final point is determined, thus establishing the step size for each step during the crawling process. and direction.

[0057] Step S3, Define the robot's state before crawling:

[0058] According to the preset step size determined in step S2 and spare step size Define two preset joint angle sets for the pitch joints of a three-branch robot when it completes the grasping state of two adjacent grasping points, denoted as preset angle one and preset angle two, respectively. The joint angles of each pitch joint in preset angle one and preset angle two are solved in advance by the inverse kinematics of the robotic arm. Specifically:

[0059] Preset angle 1 includes the angular positions that joints 2, 4, and 6 of the three robotic arms should reach under equidistant crawling conditions, corresponding to... , combined Figure 4 As shown in section (c), when the two robotic arms at the bottom of the three-branch robot grasp two adjacent gripping points respectively, and the top robotic arm does not grasp a gripping point, the specific positions are as follows:

[0060] For the robotic arm that grasps the larger number among adjacent grasping points, the joint angles of joints 2, 4, and 6 are respectively... , , ;

[0061] For the robotic arm that grasps the smaller number among adjacent grasping points, the joint angles of joints 2, 4, and 6 are respectively... , , ;

[0062] in, ;

[0063] For the robotic arm that did not grasp the gripping point, the joint angles of joints 2, 4, and 6 are respectively... , , .

[0064] Preset angle two includes the angular positions that joints 2, 4, and 6 of the three robotic arms should reach under non-equidistant crawling conditions, corresponding to... , combined Figure 5 As shown in section (c), when the two robotic arms at the bottom of the three-branch robot grasp two adjacent gripping points respectively, and the top robotic arm does not grasp a gripping point, the specific positions are as follows:

[0065] For the robotic arm that grasps the larger number among adjacent grasping points, the joint angles of joints 2, 4, and 6 are respectively... , , ;

[0066] in, ;

[0067] For the robotic arm that grasps the smaller number among adjacent grasping points, the joint angles of joints 2, 4, and 6 are respectively... , , ;

[0068] For the robotic arm that did not grasp the gripping point, the joint angles of joints 2, 4, and 6 are respectively... , , .

[0069] The specific solution methods for preset angle one and preset angle two are as follows:

[0070] when At this time, the gripping tools at the free ends of the two robotic arms at the bottom of the three-branch robot grip two adjacent numbered gripping points respectively. The center of the robot's torso is located on the perpendicular bisector of the vertical plane connecting the two gripping points. Based on the actual dimensions of the three-branch robot, the joint angles of joints 2, 4, and 6 of one of the robotic arms are solved using inverse kinematics. Generally, two sets of solutions are obtained: one set is... , , The other group is , , ,in The other robotic arm will also have two corresponding solutions, one of which is... , , The other group is , , .choose , , The joint angles of robotic arm joints 2, 4, and 6, which are used to grasp larger grasping points. , , The joint angles of robotic arm joints 2, 4, and 6, which are used to grasp smaller grasping points. , , The joint angles of robotic arm joints 2, 4, and 6, which are not gripped.

[0071] when At this time, the joint angles of joints 2, 4, and 6 of the robotic arm grasping the smaller grasping point and the robotic arm not grasping the grasping point are the same as in the case of equidistant crawling. Based on this, the joint angles of joints 2, 4, and 6 of the robotic arm grasping the larger grasping point can be calculated using inverse kinematics, generally yielding two sets of solutions: one set is... , , The other group is , , ,in ,and .choose , , The joint angles of robotic arm joints 2, 4, and 6, which are used to grasp larger gripping points.

[0072] At this point, all pitch degrees of freedom for preset angle one and preset angle two can be obtained.

[0073] Step S4: Crawling scheme determination:

[0074] The single robotic arm at the bottom of the three-branch robot configured in step S1 is grasped at the starting point of the crawling path laid out in step S2. Since there is no yaw angle issue in the first step, the step size of the first step is used as the preset step size. Or a spare step size The robot positions joints 2, 4, and 6 of its three robotic arms at preset angles (either angle one or angle two). The two bottom robotic arms grip the first two gripping points, while the top robotic arm remains idle. The three-branch robot then uses its onboard visual recognition system to execute a crawling plan: first, it determines if a yaw angle is present for the next step; if not, it further determines the next step size. If the step size is a preset value... Then perform equidistant crawling motions; if a spare step size is used... Then perform a non-equidistant crawl maneuver; if a yaw angle exists... Then, further determine the magnitude of the yaw angle. Then perform a turning and crawling maneuver, if Then, a sharp turn crawling action will be executed. The specific crawling actions are as follows:

[0075] I. Equidistant crawling

[0076] Isometric crawling refers to a movement pattern in which a robot crawls towards a target position with a fixed, preset step size without changing direction. Figure 4 The diagram illustrates the gait nodes for equidistant crawling, where (a) represents the robot's current posture (example: preset step size), (b) represents the robot's rolling motion towards the next grasping point, and (c) represents the robot's next posture (example: preset step size). The specific steps of the gait planning method are as follows:

[0077] (1) The robotic arm that grasped the smaller grasping point releases, and the robotic arm that grasped the larger grasping point is used as the power source to drive the robot to roll to the next step. After the roll is completed, the robotic arm that grasped the larger grasping point changes to the robotic arm that grasped the smaller grasping point, the robotic arm that did not grasp the grasping point changes to the robotic arm that grasped the larger grasping point, and the robotic arm that grasped the smaller grasping point changes to the robotic arm that did not grasp the grasping point.

[0078] (2) Synchronously rotate joints 2, 4 and 6 of the three robotic arms so that the joint angles of the three robotic arms reach the angle positions corresponding to the preset angle.

[0079] (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, locks the corresponding grasping point, and completes the single-step equidistant crawl.

[0080] II. Non-equidistant crawling

[0081] Non-equidistant crawling refers to a movement pattern where the robot crawls towards the target position without changing direction, but the next step length is not equal to the preset step length. Figure 5 The diagram illustrates the gait nodes for non-equidistant crawling, where (a) represents the robot's current posture (example: preset step size), (b) represents the robot's rolling motion towards the next gripping point, and (c) represents the robot's next posture (example: spare step size). The specific steps of the gait planning method are as follows:

[0082] (1) The robotic arm that grasped the smaller grasping point releases, and the robotic arm that grasped the larger grasping point is used as the power source to drive the robot to roll to the next step. After the roll is completed, the robotic arm that grasped the larger grasping point changes to the robotic arm that grasped the smaller grasping point, the robotic arm that did not grasp the grasping point changes to the robotic arm that grasped the larger grasping point, and the robotic arm that grasped the smaller grasping point changes to the robotic arm that did not grasp the grasping point.

[0083] (2) Synchronously rotate joints 2, 4 and 6 of the three robotic arms so that the joint angles of the three robotic arms reach the angle positions corresponding to the preset angle 2 respectively;

[0084] (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, locks the corresponding grasping point, and completes the single-step non-equidistant crawling.

[0085] III. Crawling around turns

[0086] Turning and crawling refers to a situation where the robot has a yaw angle of less than 90° during crawling, requiring a slight change in the crawling direction. Figure 6 The diagram illustrates the gait nodes for a turning and crawling scenario. (a) shows the robot's current posture, with the two bottom robotic arms grasping the two current gripping points. (b) shows the robot disengaging from the previous gripping point, centered on the middle gripping point. (c) shows the robot rotating around the middle gripping point to align with the next direction. (d) shows the robot's posture after rolling forward and completing the grasping action. The specific steps of the gait planning method are as follows:

[0087] (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point.

[0088] (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso deflects and aligns with the elevation plane containing the line connecting the current gripping point and the next gripping point;

[0089] (3) The robotic arm that grasps the current grasping point is used as the power source to drive the robot to roll to the next step. After the roll is completed, the robotic arm that grasps the current grasping point becomes the robotic arm that grasps the smaller grasping point in the next step, the robotic arm that does not grasp the grasping point becomes the robotic arm that grasps the larger grasping point in the next step, and the last robotic arm becomes the robotic arm that does not grasp the grasping point.

[0090] (4) If the next step size is the preset step size Then, the joints 2, 4, and 6 of the robot's three robotic arms will rotate synchronously, so that the joint angles of the three robotic arms reach the angle positions corresponding to the preset angle. If the next step size is a spare step size... Then, the joints 2, 4 and 6 of the robot's three robotic arms will rotate synchronously, so that the joint angles of the three robotic arms reach the angle positions corresponding to the preset angle two respectively.

[0091] (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, locks the corresponding grasping point, and completes the single-step turning crawl.

[0092] IV. Crawling on sharp turns

[0093] Sharp-turn crawling refers to a situation where the robot has a yaw angle of more than 90° during crawling, requiring a significant change in crawling direction. Figure 7 The diagram illustrates the gait nodes for a crawling maneuver involving sharp turns. (a) shows the robot's current posture, with the two bottom robotic arms grasping the first two gripping points. (b) shows the robot disengaging from the previous gripping point, centered on the middle gripping point. (c) shows the robot rotating to the next gripping point from the middle gripping point and completing the grasp. The specific steps of the gait planning method are as follows:

[0094] (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point.

[0095] (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso is tilted and positioned on the elevation plane where the line connecting the current gripping point and the next gripping point is located. The robotic arm that grips the current gripping point is transformed into the robotic arm that grips the smaller gripping point in the next step. The robotic arms that do not grip the gripping point remain unchanged. The last robotic arm is transformed into the robotic arm that grips the larger gripping point in the next step.

[0096] (3) Modify the corresponding parameters of preset angle one and preset angle two to adapt to the gripping role of the robotic arm after turning, specifically:

[0097] When the number of sharp turn crawls is even, the modified preset angle 1 and modified preset angle 2 are the same as the original preset angle 1 and original preset angle 2. When the number of sharp turn crawls is odd, the modified preset angle 1 and modified preset angle 2 change as follows:

[0098] Modified preset angle one:

[0099] For the robotic arm that grasps the smaller grasping point, the angles of joints 2, 4, and 6 are respectively , , ;

[0100] For the robotic arm that grasps larger grasping points, the angles of joints 2, 4, and 6 are respectively... , , ;

[0101] For the robotic arm that did not grasp the gripping point, the angles of joints 2, 4, and 6 are respectively , , ;

[0102] Modified preset angle two:

[0103] For the robotic arm that grasps the smaller grasping point, the angles of joints 2, 4, and 6 are respectively , , ;

[0104] For the robotic arm that grasps larger grasping points, the angles of joints 2, 4, and 6 are respectively... , , ;

[0105] For the robotic arm that did not grasp the gripping point, the angles of joints 2, 4, and 6 are respectively , , ;

[0106] (4) If the next step size is the preset step size Then, the joints 2, 4, and 6 of the robot's three robotic arms will rotate synchronously, so that the joint angles of the three robotic arms reach the angle positions corresponding to the modified preset angle. If the next step size is a spare step size... Then, the joints 2, 4 and 6 of the robot's three robotic arms will rotate synchronously, so that the joint angles of the three robotic arms reach the angle positions corresponding to the modified preset angle 2 respectively.

[0107] (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, locks the corresponding grasping point, and completes the single-step sharp turn crawl.

[0108] Step S5: Crawling task terminated.

[0109] During the crawling process, after each grasping point, the three-branch robot uses its onboard vision recognition system to determine whether the next grasping point is the final point. If it is not the final point, the crawling plan in step S4 continues. If it is the final point, when any of the three-branch robot's robotic arms grasps the final point, it is considered that the end of the path has been reached. At this time, the second to last grasping point is released first, and then all joints of the robot's three robotic arms are moved to the zero position to end the crawling task.

[0110] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0111] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A crawling gait planning method for a multi-branch robot, characterized in that: Includes the following steps: Step S1, Initial Robot Configuration: Configure a three-branch robot with three symmetrical seven-degree-of-freedom robotic arms evenly arranged circumferentially along the edge of the robot's body. The seven joints of each robotic arm are all rotational joints, and the rolling and pitching are alternately arranged from the connecting end of the robotic arm to the free end. Among them, joints 1, 3, 5, and 7 are rolling degrees of freedom, and joints 2, 4, and 6 are pitching degrees of freedom. In the zero position, the center points of the seven joints are on the same straight line, and all pitch joints are parallel to each other. The free end of the robotic arm is equipped with a gripping tool for gripping the gripping point on the crawling path. In the initial state, the three-branch robot is evenly arranged in a Y shape. Step S2, Pre-crawling path planning: Based on the starting and ending points of the actual crawling path, pre-plan the layout along the path. There are several gripping points, and their placement is restricted so that the distance between any two adjacent gripping points is only divided into preset steps. and spare step size Two kinds, The yaw angle is set between adjacent steps according to the requirements, and the grab points are numbered according to the crawling sequence. Determine the step length for each step during the crawling process. and direction; Step S3, Robot state definition before crawling: Based on the preset step size and spare step size Define a set of preset joint angles for each pitch joint under two adjacent gripping point gripping states, denoted as preset angle one and preset angle two, and solve the joint angles of each pitch joint in advance through inverse kinematics; Step S4: Crawling Scheme Determination: The bottom single robotic arm of the three-branch robot configured in Step S1 grasps the starting point of the crawling path laid out in Step S2. First, based on the step length of the first step, the pitch joints of the robot's three robotic arms are moved to the corresponding angle positions, so that the two robotic arms at the bottom of the robot grasp the first two grasping points respectively, while the robotic arm at the top of the robot remains idle. Then, the crawling scheme is planned using the visual recognition system: it is determined whether there is a yaw angle in the next step. If there is no yaw angle, the step length for the next step is determined, and the step length is the preset step length. Perform equidistant crawling movements, with the step size being the spare step size. Perform non-equidistant crawling maneuvers; if a yaw angle exists. Then determine the magnitude of the yaw angle. When performing a turning and crawling maneuver, Perform a sharp turn and crawl maneuver at the same time; Step S5, Crawling Task Termination: After each grasping point, determine whether the next grasping point is the final point. If it is not the final point, continue to execute the crawling plan in step S4. If it is the final point, first release the second to last grasping point, and then move all joints of the robot's three robotic arms to the zero position to end the crawling task.

2. The crawling gait planning method for a multi-branch robot according to claim 1, characterized in that: The preset angle corresponds to the step size. In the equidistant crawling scenario, when two robotic arms of the three-branch robot respectively grasp two adjacent grasping points, and the third robotic arm does not grasp any grasping points: the joint angles of joints 2, 4, and 6 of the robotic arm that grasps the larger grasping point are respectively... , , ; The robotic arm that grasps the smaller grasping point has joint angles of joints 2, 4, and 6 as follows: , , ,and For the robotic arm that did not grasp the gripping point, the joint angles of joints 2, 4, and 6 are respectively... , , .

3. The crawling gait planning method for a multi-branch robot according to claim 2, characterized in that: The preset angle corresponds to the step size. In the non-equidistant crawling scenario, the joint angles of joints 2, 4, and 6 of the robotic arm that grasps the smaller-numbered grasping point and the robotic arm that does not grasp any grasping points are the same as the preset angle 1. For the robotic arm that grasps the larger-numbered grasping point, the joint angles of joints 2, 4, and 6 are respectively... , , ,and .

4. The crawling gait planning method for a multi-branch robot according to claim 1, characterized in that: The specific steps of the equidistant crawling action are as follows: (1) The robotic arm that gripped the smaller gripping point releases, and the robotic arm that gripped the larger gripping point becomes the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation. (2) Rotate joints 2, 4 and 6 of the three robotic arms synchronously so that the joint angles of each robotic arm reach the angle positions corresponding to the preset angle. (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

5. The crawling gait planning method for a multi-branch robot according to claim 1, characterized in that: The specific steps of the non-equidistant crawling action are as follows: (1) The robotic arm that gripped the smaller gripping point releases, and the robotic arm that gripped the larger gripping point becomes the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation. (2) Rotate joints 2, 4 and 6 of the three robotic arms synchronously so that the joint angles of each robotic arm reach the angle positions corresponding to the preset angle 2. (3) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

6. The crawling gait planning method for a multi-branch robot according to claim 1, characterized in that: The specific steps of the turning and crawling maneuver are as follows: (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point. (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso deflects and aligns with the elevation plane containing the line connecting the current gripping point and the next gripping point; (3) The robotic arm that grasps the current grasping point is used as the power source to drive the robot to roll to the next step. After the roll is completed, the three robotic arms complete the role rotation. (4) The next step size is the preset step size. Or a spare step size Simultaneously rotate joints 2, 4, and 6 of the three robotic arms to the angle position corresponding to preset angle one or preset angle two; (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

7. The crawling gait planning method for a multi-branch robot according to claim 1, characterized in that: The specific steps of the sharp turn crawling maneuver are as follows: (1) The robotic arm that gripped the smaller gripping point is released, and the joint 6 of the robotic arm that gripped the larger gripping point is rotated to adjust the robot's posture, so that the robotic arm that gripped the smaller gripping point is disengaged from the corresponding gripping point. (2) Adjust the yaw angle The value is assigned to joint 7 of the robotic arm that grasps the larger grasping point, causing it to rotate. The angle is adjusted so that the robot's torso is tilted and positioned on the vertical plane where the line connecting the current gripping point and the next gripping point is located, thus completing the change of the robotic arm's gripping role. (3) Modify the corresponding parameters of preset angle one and preset angle two to adapt to the gripping role of the robotic arm after turning. When the number of sharp turn crawls is even, the modified preset angle one and modified preset angle two are consistent with the original preset angle one and original preset angle two. When the number of sharp turn crawls is odd, the modified preset angle one and modified preset angle two change as follows: Modified preset angle 1: For the robotic arm grasping the smaller grasping point, the angles of joints 2, 4, and 6 are respectively... , , For the robotic arm that grasps the larger grasping point and the robotic arm that does not grasp the grasping point, joints 2, 4, and 6 are respectively , , ; Modified preset angle two: For the robotic arm grasping the smaller grasping point, the angles of joints 2, 4, and 6 are respectively , , For the robotic arm that grasps the larger grasping point and the robotic arm that does not grasp the grasping point, joints 2, 4, and 6 are respectively , , ; (4) The next step size is the preset step size. Or a spare step size Simultaneously rotate joints 2, 4, and 6 of the three robotic arms to the angle positions corresponding to the modified preset angle one or preset angle two; (5) The robotic arm to be grasped moves to the target grasping point, closes the gripping tool at its free end, and locks the corresponding grasping point.

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