A natural indirect adaptive controller for a satellite-mounted manipulator

The work considers the design of an indirect adaptive controller for a satellite equipped with a robotic arm manipulating an object. Model uncertainty on the manipulated object can considerably impact the overall behavior of the system. In addition, the dynamics of the actuators of the base satellite are non-linear and can be affected by malfunctioning. Neglecting these two phenomena may lead to excessive control effort or to performance degradation. To deal with these issues, an indirect adaptive control approach is pursued in this paper, which allows consideration of relevant features of the actuators’ dynamics, such as loss of effectiveness. Furthermore, an adaptive law that preserves the physical consistency of the inertial parameters of the various rigid bodies comprising the system is employed. The performance and robustness of the controller are first analyzed and then validated in a realistic simulation study.