The investigation of the maneuverability deterioration based on acceleration radius theory

Maneuverability is the measure of the dynamic performance of a manipulator in a specific posture or configuration, and acceleration radius is one of the most utilized indices of it. Acceleration radius can be utilized as the reference to judge whether further dynamic analysis should be performed when evaluating the controllability and feasibility of the manipulator following the prescribed path with assigned kinematic and kinetic requirements in the planning phase. When utilizing acceleration radius as the dynamic reference in the planning phase, it can prevent wasting the calculation cost due to these non-necessary dynamic analyses, and it can also be utilized as the benchmark in the on-line control.However, the existence of the configuration errors is inevitable in reality, and it deteriorates the dynamic performance of a manipulator with the ideal configuration parameters and leads to the potential risk of failing to achieve an assigned dynamic task. To investigate the adverse behavior caused by the configuration errors and to provide some clues to avoid or reduce their influence, this article proposes a novel and systematic method which can be used to evaluate the maneuverability deterioration of a non-redundant serial manipulator system due to the influence of configuration errors, and it also provides an index, deterioration rate, to quantitate this kind of deterioration. Deterioration rate can be utilized to quantitate the maneuverability deterioration due to the influence of configuration errors in a prescribed workspace or region and can also be treated as the safety or derating margin when proceeding with the control or path planning.