Trot Gait Control of an Underactuated Planar Quadruped Robot via Hybrid Zero Dynamics

Dynamically stable control methods are crucial for quadruped robot locomotion. This study focuses on applying a time-invariant control technique, specifically the Hybrid Zero Dynamics (HZD) approach, to enhance the trot gait of underactuated planar quadruped robots. A comparison with a common time-variant method, Proportional-Derivative (PD) feedback control, and a parametric investigation of both techniques are also presented. The case study involves a six-link, knee-less quadruped robot model with four degrees of freedom, for which the dynamic equations are carefully formulated for both continuous and impact phases. Simulations conducted in MATLAB compare and analyze the control parameters of the two methods. The results indicate that the proposed HZD approach yields more symmetric and uniform movements while requiring lower control effort compared to the PD method. Interestingly, as control gains increase in the PD method, its performance and control efforts begin to resemble those of the HZD approach. This research offers a detailed investigation of the simulation outcomes and control parameters, contributing to potential improvements in quadruped robot trot gait performance.

کلیدواژه ها:

Quadruped robot ، Dynamically stable control ، Hybrid Zero Dynamics ، Trot Gait ، Underactuated