Hybrid Position-Compliance Control of Redundantly Actuated Parallel Kinematic Manipulators (RA-PKM) Equipped with Serial Elastic Actuators (SEA)
Sprache des Vortragstitels:
92nd Annual Meeting of the International Association of Applied Mathematics and Mechanics
Sprache des Tagungstitel:
Redundantly actuated parallel kinematic manipulators (RA-PKM) are ideal candidates in robotic applications combining dynamic performance with high accuracy. Actuation redundancy further allows for modulation of the end-effector (EE) stiffness. A recent trend in robotics is the use of inherently compliant and elastic components, eventually leading to soft continuum robots, which shall provide tailored solutions for human-robot collaboration and assistance applications. One way to introduce compliance is to use serial elastic actuators (SEA). This yields two kinematically decoupled dynamic systems, the RA-PKM mechanism and the actuation system, that are force-coupled by (passive) elastic elements, where the DOF of the actuation system exceeds the DOF of the RA-PKM according to the degree of actuation redundancy. Due to the kinematic decoupling the RA-KM is underactuated.
Thus standard model-based control methods for fully actuated systems (e.g. servo constraints, augmented PD) are not applicable. Therefore, a flatness-based position control is proposed, along with a stiffness modulation approach. Results are presented for a planar 2RR/RRR RA-PKM.