Motion control strategy for robot manipulators in the neighbourhood of singularities

BEATRIZ MORALES; RICARDO CARELLI; CECILIA GARCÍA

Buenos Aires

Simposio; 4th. International Symposium on Intelligent Components and Instruments for Control Applications, SICICA 2000; 2000

Asociación Argentina de Control Automático, AADECA

In this work, a control strategy applied to robot manipulators operating close to singularities is presented. The robot is considered to be in contact with the environment and close to the singularity region. Robot manipulator control is through a PD controller with inverse dynamic. Due to its interaction with the environment, the manipulator incorporates an impedance loop that modifies the robot reference according to the interaction force. In the vicinity of the singularity, the algorithm generates a fictitious force to which a second impedance function is applied. This causes a small deviation to the original robot trajectory to avoid the singularity region. The algorithm is based on the minimum singular value in order to generate the module and direction of the fictitious force. This strategy is applied to a teleoperation system without time delay.