Model-independent performance tracking control of robotic arm-hand systems

In this paper, we present a novel robust adaptive performance tracking control strategy for robotic arm-hand systems to achieve trajectory tracking in the joint space. A scaling error transformation is incorporated into an asymmetrical barrier function to guarantee prescribed performance specifications for the output angular displacement errors. To handle unknown parameter uncertainties, fundamental properties of the system matrices utilized, such that the complex matrix computation can be converted into simple scalar computation. The immediate benefit of this way is that a model-independent robust adaptive performance tracking control strategy can be implicitly derived. Also, with the minimum eigenvalue of the designed positive definite matrix being inserted into the controller structure, the need for system-related term analysis during control design and stability assessment can be circumvented. Furthermore, by virtue of the performance tracking method, a fingertip position control scheme in the operational space is developed. The numerical simulations show the effectiveness of the proposed dynamic model and control schemes.