Control in Robotics and Automation

Abstract

The main motivation of this chapter is to take a step toward intelligent robotic systems through the combination of event-based motion planning and nonlinear feedback control. In this research, an integrated event-based planning and control method has been developed using a motion reference variable other than time. It has been successfully applied to single-robot arm motion planning and control, as well as multi-robot coordination planning and control. A new planning and control scheme—event-based planning and control—has been developed. Instead of time, the events of a system are used as a motion reference to describe the motion plan and to drive the system. The time is implicitly included inside the motion plan and the control process. The planning along with the feedback control becomes a real-time dynamic process. The event-based planning and control theory has been applied to single-robot motion planning and control. The time and energy optimization techniques are used to determine event-based trajectories. The significance of the event-based motion planning and control scheme is its compatibility with sensor-based planning and control, because sensed events in robotic manipulation rarely, if ever, occur in a precise time scale. The event-based motion reference for the planning and control of coordinated robots has been introduced. It drives the system to achieve an optimal coordination. A new hybrid position-force controller has been developed. It incorporates the robot dynamics as well as the dynamics of robot joint motors. The event-based multi-robot coordination scheme is developed with a consideration of the implementation. It naturally lends itself to a distributed computing architecture.