Flying Trot Control Method for Quadruped Robot Based on Trajectory Planning

TL;DR

This paper introduces a control method for quadruped robots to perform flying trot gaits by integrating offline trajectory planning with real-time balance control, inspired by animal motion analysis.

Contribution

It presents a novel control framework combining trajectory planning, posture adjustment, CoM regulation, and active compliance for flying trot gait in quadruped robots.

Findings

Maximum speed reached 4.73 body lengths per second.

The control method effectively maintains stability during dynamic running.

Simulation and experiments validate the approach's feasibility.

Abstract

An intuitive control method for the flying trot, which combines offline trajectory planning with real-time balance control, is presented. The motion features of running animals in the vertical direction were analysed using the spring-load-inverted-pendulum (SLIP) model, and the foot trajectory of the robot was planned, so the robot could run similar to an animal capable of vertical flight, according to the given height and speed of the trunk. To improve the robustness of running, a posture control method based on a foot acceleration adjustment is proposed. A novel kinematic based CoM observation method and CoM regulation method is present to enhance the stability of locomotion. To reduce the impact force when the robot interacts with the environment, the virtual model control method is used in the control of the foot trajectory to achieve active compliance. By selecting the proper parameters for the virtual model, the oscillation motion of the virtual model and the planning motion of the support foot are synchronized to avoid the large disturbance caused by the oscillation motion of the virtual model in relation to the robot motion. The simulation and experiment using the quadruped robot Billy are reported. In the experiment, the maximum speed of the robot could reach 4.73 times the body length per second, which verified the feasibility of the control method.