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CN-121994247-A - Differential robot and track planning method, device and storage medium thereof

CN121994247ACN 121994247 ACN121994247 ACN 121994247ACN-121994247-A

Abstract

The application relates to the technical field of robots and discloses a differential robot, a track planning method, a track planning device and a storage medium thereof, wherein the method comprises the steps of generating a continuous time parameterized spline track by taking the pose projection position of the differential robot on a two-dimensional plane as a flat output variable based on the differential flat characteristic of the differential robot; the method comprises the steps of obtaining a spline track, calculating the linear speed of a differential robot at each moment according to the spline track, identifying an operation period when the linear speed is lower than a set linear speed threshold value, reconstructing an orientation angle change path in the current operation period by utilizing the kinematic characteristic that the differential robot allows in-situ rotation for the identified operation period on the premise of keeping the position change rule of the original spline track unchanged, and generating a complete motion track containing corrected direction information as a target motion track of the differential robot.

Inventors

  • ZHANG JIAXIN

Assignees

  • 深圳市优必选科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260224

Claims (10)

  1. 1. The differential robot track planning method is characterized by comprising the following steps of: based on differential flat characteristics of the differential robot, taking the pose projection position of the differential robot on a two-dimensional plane as a flat output variable to generate a continuous time parameterized spline track, wherein the spline track meets the constraint of a safe passage corridor; calculating the linear speed of the differential robot at each moment according to the spline track, and identifying an operation period when the linear speed is lower than a set linear speed threshold; And reconstructing a direction angle change path in the current operation period by utilizing the kinematic characteristic of the differential robot allowing in-situ rotation on the premise of keeping the position change rule of the spline track unchanged, and generating a complete motion track containing corrected direction information as a target motion track of the differential robot.
  2. 2. The differential robot trajectory planning method of claim 1, wherein generating a continuous time parameterized spline trajectory based on differential flatness characteristics of the differential robot using a pose projection position of the differential robot on a two-dimensional plane as a flat output variable comprises: Modeling the pose projection position as a continuous function which changes with time by utilizing the differential flat characteristic of the differential robot; a piecewise fifth-order polynomial is adopted to represent the time evolution process of the continuous function which changes along with time, so that a continuous path formed by a plurality of track segments is formed; And converting the optimized variable into all coefficients of five-order polynomials of each track segment through a predefined analytic mapping relation by taking position coordinates and corresponding operation time length at the connecting point of each track segment as optimized variables, and obtaining a continuous-time parameterized spline track under the condition of meeting position, speed and acceleration continuity.
  3. 3. The differential robot trajectory planning method according to claim 1, characterized in that the calculating the linear velocity of the differential robot at each moment from the spline trajectory and identifying the operation period in which the linear velocity is lower than a set linear velocity threshold value includes: Solving a first derivative of the pose projection position in the spline track with respect to time to obtain speed components at each time point, and synthesizing the corresponding linear speed according to the speed components; And traversing the whole time interval of the spline track, and identifying the time interval of which the linear velocity is smaller than the set linear velocity threshold value so as to determine a low-speed running period required to be subjected to direction reconstruction processing.
  4. 4. The differential robotic trajectory planning method of claim 1, wherein said reconstructing the angular change of direction path within the current run period comprises: Taking the actual orientation angle of the differential robot at the beginning of the operation period as an initial reference, and taking the target orientation angle required to be reached at the end of the operation period as a terminal reference; On the premise of keeping the actual position state of the differential robot in the operation period unchanged, a continuous orientation angle change path from the initial reference to the terminal reference is constructed by adopting a mode of uniform angular velocity rotation or polynomial interpolation.
  5. 5. The differential robotic trajectory planning method of claim 1, wherein the constructing of the safety corridor comprises: and acquiring barrier distribution information in the environment, and combining the outline dimension of the differential robot and a preset safety margin to generate a safety passage corridor comprising a plurality of mutually overlapped convex areas.
  6. 6. The differential robotic track planning method of claim 5, wherein generating a continuous time parameterized spline track further comprises: Constructing a nonlinear optimization problem, wherein the nonlinear optimization problem takes the minimum total movement time as a primary optimization target and takes control energy consumption as an auxiliary target; And solving the nonlinear optimization problem under the conditions of meeting the conditions of initial and termination state matching, track high-order continuity, dynamic physical amplitude limiting, geometric constraint applied by a safety passage corridor and linear speed lower limit constraint for avoiding singularity of differential flat mapping in a low-speed region, and generating a continuous time parameterized spline track.
  7. 7. The differential robot trajectory planning method according to claim 5, wherein the acquiring the obstacle distribution information in the environment and combining the outline dimension of the differential robot with a preset safety margin, generating a safety passage corridor including a plurality of mutually overlapping convex areas, comprises: Acquiring barrier distribution information in the environment, and generating an initial reference path by combining the outline dimension of the differential robot and a preset safety margin; constructing a corresponding convex region by taking a discrete path point on the initial reference path as a center; the convex areas are ensured to be overlapped with each other by restraining the distance between the central points of the adjacent convex areas to be smaller than twice the expansion radius; The position or size of the male regions is adjusted such that the first male region contains a starting position and the last male region contains a target position to form the safety corridor.
  8. 8. A differential robot trajectory planning device, comprising: The spline track generation module is used for generating a continuous time parameterized spline track by taking the pose projection position of the differential robot on a two-dimensional plane as a flat output variable based on the differential flat characteristic of the differential robot, wherein the spline track meets the constraint of a safe passage corridor; The operation period identification module is used for calculating the linear speed of the differential robot at each moment according to the spline track and identifying the operation period when the linear speed is lower than a set linear speed threshold; And the singularity processing module is used for reconstructing a direction angle change path in the current operation period by utilizing the kinematic characteristic that the differential robot allows in-situ rotation on the basis of keeping the position change rule of the spline track unchanged, and generating a complete motion track containing corrected direction information as a target motion track of the differential robot.
  9. 9. A differential robot, characterized in that it comprises a processor and a memory, the memory storing a computer program, the processor being adapted to execute the computer program to implement the differential robot trajectory planning method of any one of claims 1-7.
  10. 10. A computer readable storage medium, characterized in that it stores a computer program which, when executed on a processor, implements the differential robot trajectory planning method according to any one of claims 1-7.

Description

Differential robot and track planning method, device and storage medium thereof Technical Field The present application relates to the field of robots, and in particular, to a differential robot, and a method, an apparatus and a storage medium for track planning thereof. Background In the prior art, in the differential robot track optimization method, modeling modes such as multiple dependency points, grids or distance functions are adopted in obstacle avoidance processing, the formed obstacle avoidance constraint generally has non-convexity and strong non-linear characteristics, so that the optimization problem is difficult to converge, long in solving time, easy to fall into a local optimal solution, and difficult to meet the requirements of planning instantaneity and running stability in practical application. Disclosure of Invention In view of this, the embodiments of the present application provide a method, an apparatus, a differential robot, and a computer-readable storage medium for track planning of a differential robot, so as to achieve safe, smooth, and physically feasible track generation. In a first aspect, an embodiment of the present application provides a method for planning a track of a differential robot, including: based on differential flat characteristics of the differential robot, taking the pose projection position of the differential robot on a two-dimensional plane as a flat output variable to generate a continuous time parameterized spline track, wherein the spline track meets the constraint of a safe passage corridor; calculating the linear speed of the differential robot at each moment according to the spline track, and identifying an operation period when the linear speed is lower than a set linear speed threshold; And reconstructing a direction angle change path in the current operation period by utilizing the kinematic characteristic of the differential robot allowing in-situ rotation on the premise of keeping the position change rule of the spline track unchanged, and generating a complete motion track containing corrected direction information as a target motion track of the differential robot. In an alternative embodiment, the generating a continuous time parameterized spline track based on differential flatness characteristics of the differential robot and using pose projection positions of the differential robot on a two-dimensional plane as flat output variables includes: Modeling the pose projection position as a continuous function which changes with time by utilizing the differential flat characteristic of the differential robot; a piecewise fifth-order polynomial is adopted to represent the time evolution process of the continuous function which changes along with time, so that a continuous path formed by a plurality of track segments is formed; And converting the optimized variable into all coefficients of five-order polynomials of each track segment through a predefined analytic mapping relation by taking position coordinates and corresponding operation time length at the connecting point of each track segment as optimized variables, and obtaining a continuous-time parameterized spline track under the condition of meeting position, speed and acceleration continuity. In an optional embodiment, the calculating the linear velocity of the differential robot at each moment according to the spline track, and identifying the operation period in which the linear velocity is lower than the set linear velocity threshold value includes: Solving a first derivative of the pose projection position in the spline track with respect to time to obtain speed components at each time point, and synthesizing the corresponding linear speed according to the speed components; And traversing the whole time interval of the spline track, and identifying the time interval of which the linear velocity is smaller than the set linear velocity threshold value so as to determine a low-speed running period required to be subjected to direction reconstruction processing. In an alternative embodiment, said reconstructing the orientation angle change path in the current operation period includes: Taking the actual orientation angle of the differential robot at the beginning of the operation period as an initial reference, and taking the target orientation angle required to be reached at the end of the operation period as a terminal reference; On the premise of keeping the actual position state of the differential robot in the operation period unchanged, a continuous orientation angle change path from the initial reference to the terminal reference is constructed by adopting a mode of uniform angular velocity rotation or polynomial interpolation. In an alternative embodiment, the construction of the safety corridor comprises: and acquiring barrier distribution information in the environment, and combining the outline dimension of the differential robot and a preset safety margin to generate a safety pas