Reactive Control of a Mobile Manipulator Using Pseudo-Joint Damping
Ward, Keith Ronald
Arkin, Ronald C.
MetadataShow full item record
Reactive control for mobile manipulation involves a tight coupling of sensors to motor response. Pseudo-forces exerted on the end-effector and limbs of the mobile manipulator must be distributed over the entire structure. Pseudo-joint damping provides a mechanism for this process. Damping functions were used to create motion of the end-effector which emulated the characteristics of biological systems. The target biological characteristics were a general bell-shaped curve of the end-effector speed profile, an initial and final end-effector speed of zero, and a scaling of the speed profile with distance to goal. The damping functions were then evaluated for time, distance, safety, and flexibility to determine if the biological characteristics corresponded to improved performance of the mobile manipulator. The simulations showed that by reproducing the characteristics of biological systems, improved performance of the mobile manipulator was realized. The set of linear and square damping functions were found to perform best in a series of varying environments. Both damping functions were shown to produce different ending configurations of the arm, and to be more or less aggressive by varying the damping parameters in the functions. This allows the performance of the mobile manipulator to be adjusted based on any a priori information about the environment.