MODELING, IDENTIFICATION, AND CONTROL OF A PNEUMATICALLY ACTUATED, FORCE CONTROLLABLE ROBOT

This research focuses on modeling and control of a light-weight and in expensive pneumatic robot that can be used for position tracking and f or end-effector force control. Unlike many previous controllers, our a pproach more fully accounts for the nonlinear dynamic properties of pn eumatic systems such as servovalve how characteristics and the thermod ynamic properties of air compressed in a cylinder. We show with theory and experiments that pneumatic actuators can rival the performance of more common electric actuators. Our pneumatic robot is controlled by extending existing manipulator control algorithms to handle the nonlin ear how and compressibility of air. The control approach uses the tria ngular form of the coupled rigid body and air how dynamics to establis h path tracking, In addition to the trajectory tracking control law, a hybrid position/force control algorithm is developed. The experimenta l results indicate that the tip forces on the robot can be controlled without the need for an expensive force/torque sensor usually required by electric motor driven systems.