Mathematical Model and Control Simulation of Hexapod Robot Locomotion in Tripod Gait

Abstract

This paper presents the research of a hexapod robot as it movement along a defined path. Firstly, the performance of the robot product architecture is presented and a mathematical kinematic model of the robot is derived according to it, i.e. its legs using the Denavit-Hartenberg method and homogeneous transformations. The purpose of this was to obtain the equations of inverse kinematics. A simplified robot product architecture based on rectangular robot design was used to perform the mathematical model. It is shown by a simplified kinematic scheme. In addition, a control algorithm was performed using a PID controller in each ankle. The controller’s parameters are adjusted on one leg of the robot, and after that, this is used to adjust the control on the other legs in this way. The simulation of the controlled motion of the robot was performed using the computer program MATLAB Simulink and the Simscape Multibody environment. In doing so, only the robot's movement on flat terrain was observed. The tripod gait was chosen for the motion model due to the simplicity of creating the model and performing the simulation, as well as the speed of movement.