Identification of actuation efforts using limited sensory information for space robots

Autonomous space robots are needed for future missions such as satellite capture and large space structure construction. Precise control of these space robots is important for space missions but real world factors such as unpredictable actuator behavior can degrade performance. Sensing capabilities in space robots to measure and compensate for this uncertainty are limited by the practical issues of issues of weight, complexity and reliability. This paper presents a method that does multi-actuator sensing with a reduced number of actuators. A force/torque sensor is mounted between a space robot´s spacecraft and its manipulators and is used to identify manipulator joint actuator outputs while simultaneously estimating spacecraft thruster forces and moments. Theoretical development and simulation results are presented