Trajectory Parameter Optimization of a Six-legged Robot Following an Elliptical Trajectory

This study proposes a locomotion method applicable to a 6-legged mobile robot with passive wheels. To achieve the desired movements of the robot, it is necessary to control the end points of the robot's legs to reach specific target positions. Leg end point positions can be defined relative to the robot's central coordinate system through kinematic modeling, which includes both forward and inverse kinematics. This study equips the proposed robot with passive wheels at the ends of its legs to facilitate movement through its actions. The robot's locomotion is planned by tracking an elliptical trajectory at its leg end points, and it gains propulsion for linear movement through the relationship between the absolute velocity of the wheels relative to the ground and the relative velocity of the legs in the robot's frame. The robot's performance is evaluated through 236 experiments, using the height, xaxis length, and y-axis length of the elliptical trajectory as design parameters. The results indicate that the optimal trajectory is achieved at a height of 92.5mm, with x-axis and y-axis lengths of 120mm and 70mm, respectively. Future research will focus on designing a mechanism for flexible switching between wheels and legs, as well as analyzing steering performance.