Research On Motion Planning Method For Quadruped Robot Waling On Stair-like Terrain

Based on a self-designed quadruped robot experimental platform,this article studies the stable walking of quadruped robots on stair-like terrain without external perception sensors.A high stability and robustness control system is designed,which effectively improves the stability of quadruped robots walking on stair-like terrain.Specifically,it includes the following contents:(1)Based on the functional requirements of the robot,a software and hardware control architecture is designed.UP board is selected as the core hardware device,and the SPI-to-CAN communication method is used to communicate with the joint motor.In addition,according to the requirements of the functional implementation,the control algorithm is divided into different modules,such as low-level communication and upper-level control.(2)The D-H table is listed based on the structural parameters of the quadruped robot,and the forward and inverse kinematics solutions are obtained.Secondly,a robot centroid navigation algorithm based on leg odometer is designed according to the kinematic model,which successfully estimates the position and velocity of the robot centroid.Finally,the single rigid body dynamic model of the quadruped robot is completed,thus completing the modeling work of the quadruped robot.(3)A climbing gait with high stability margin is designed for the quadruped robot,and a foot trajectory with obstacle avoidance characteristics is designed using polynomial fitting.In addition,by analyzing the characteristics of stair-like terrain,a three-dimensional plane fitting slope estimation algorithm combining foot pose is proposed.Finally,by using the obtained terrain information to adjust the foot position and body posture of the robot,and by using the model predictive control(MPC)algorithm to calculate the foot reaction force that meets the climbing task,stable walking of the quadruped robot on stair-like terrain is achieved.(4)The slope estimation algorithm and motion control strategy proposed in this article are deployed on the simulation and physical robot platforms,successfully achieving smooth walking of the robot on stair-like terrain with a height of 10 cm and a roll fluctuation less than 3.6°.This verifies the feasibility and effectiveness of the motion control algorithm proposed in this article.The quadruped robot control system proposed in this article effectively achieves stable walking of the robot on stair-like terrain,providing a certain reference value for the walking of quadruped robots in unstructured terrain.