LYAPUNOV-BASED CONTROL OF A ROBOT AND MASS-SPRING SYSTEM UNDERGOING AN IMPACT COLLISION

The control of a dynamic system that transitions from free motion to motion with a deformable surface is challenging problem of practical concern for robotics applications. A control challenge for these systems is that the equations of motion are different when the system status changes suddenly from a non-contact state to a contact state. A nonlinear controller is designed to command a robot to collide with a deformable unactuated mass-spring system and regulate the spring-mass to a desired compressed state. Lyapunov-based methods are used to develop a continuous controller that yields global asymptotic regulation of the spring-mass and robot links. Unlike some other results in literature, the developed continuous force controller does not depend on sensing the impact, measuring the impact force, or the measurement of other acceleration terms. Experimental results are provided to validate our analysis.