An Adaptive Controller for Robotic Manipulators with Unknown Kinematics and Dynamics

The ability for kinematics to adapt is important for robotic systems applied in complex environments. This paper focuses on the trajectory control problems of a robotic system with varying kinematics at the end-effector. A new adaptive control approach is developed for robotic manipulators with unknown kinematics and dynamics. This is achieved by using a model-free adaptive controller combined with a kinematics observer. The introduced kinematics observer allows for estimating the kinematic parameters, even under some unconventional application scenarios where typical image processing based techniques are not applicable. Stability of the model-free control with kinematics observer is proven. Control performance and estimation results have been assessed for a wider range of scenarios in a simulation environment which incorporates full nonlinear arm dynamics, finite sampling time and sensor noise.