Trajectory planning for a quadruped robot.

摘要

This thesis presents the development of a trajectory planner for a four legged robot. This study is the initial step toward integrating a quadruped robot into a team of wheeled robots available in the Robotics lab at the department of Mechanical Engineering at RMC. For the purposes of this thesis, the specifics of the SILO 4 robot have been used in the trajectory planner. The trajectory planner that has been developed can be implemented on any quadruped robot with the insect leg architecture.The trajectory planner allows a quadruped robot to closely follow a given two dimensional path by producing the required joint positions, velocities and accelerations. Appropriate gaits are used in conjunction with stability analysis, leg and body trajectories, and kinematic equations to allow for omni-directionality of locomotion, simplicity of implementation and maintenance of static stability.The trajectory planner used a two phase discontinuous creeping gait in conjunction with a discontinuous spinning gait to plan the different foot and body positions to follow a desired path. Static stability was checked and maintained throughout the gaits by ensuring that the projection of the centre of gravity would always remain within the support polygon. The body and foot positions produced by the gaits were joined using appropriate trajectories and then the Inverse Kinematic Problem was solved to produce joint trajectories that would allow a quadruped to follow a desired path. The dynamics of the robot legs were also developed and the produced joint variables were then used to obtain torque requirements to allow the motors to be sized.