Evaluation of Dynamic Performance of Non-Spherical Parallel Orientation Manipulators through Bond Graph Multi-Body Simulation

摘要

Dynamic performance of a parallel orientation manipulator requiring a small form factor is primarily determined by the dynamic response of the corresponding actuators. Hence, identifying a suitable kinematic architecture for such a manipulator is constrained by the choice of the actuator, which is based on several application-specific requirements such as dynamics, compactness, positioning accuracy, etc. The kinematic topology of each of the two architectures that can accommodate a prospective voice coil linear motor consists of three identical closed loops. These two candidate architectures are compared, one of which requires the actuator bodies to rotate, thereby introducing inertial effects that impact performance. This paper quantifies the performance improvements when no such inertial effects are present. Through dynamic simulation of the multi-body systems resulting from the candidate architectures, the architecture that provides superior performance in terms of settling times and expended energy in a random robotic maneuver can be identified. For this purpose, the multibody models of the candidate architectures were developed and subsequently a Monte-Carlo performance benchmarking study was conducted. This study identified the architecture in which the actuator bodies did not rotate to be more desirable, as indicated by lower settling times and lower expended energy in executing a set of random maneuvers. The multi-body dynamic models were developed in bond graph formalism because of the flexibility it offers for modeling closed loop kinematic systems that are free of causal conflicts.