Improving the design of high speed mechanisms through multi-level kinematic synthesis, dynamic optimization and velocity profiling

- This paper presents a layered mechanism design optimisation approach.
- It enables kinematic and dynamic optimisation combined with velocity profiling.
- The approach is applied to an industrial mechanism design problem.
- A reconfigurable test rig was constructed to validate performance gains.
- Experimental results confirm an overall reduction of 85% in peak-to peak torque.

This paper deals with the fundamental mechanical engineering challenge of mechanism design. While there is a significant body of research associated with mechanism design there are few, if any, approaches that consider kinematic synthesis and optimisation of dynamic performance in an integrated manner. To address this gap, this paper presents a layered (multi-level) design optimisation approach that enables kinematic and dynamic optimisation combined with velocity profiling of the motor/drive system. The approach is presented for both new design and redesign tasks, and is based on the use of inverse kinematic and inverse dynamic analysis, and a novel strategy for generating instantiations of spatial mechanisms that satisfy kinematic quality indicators but with improved dynamic performance. The experimental results validate not only the individual stages of the approach and the models but also the overall improvements achievable through the application of the method. In this regard, the experimental (practical) mechanism exhibited performance improvements in the peak-to-peak torque of 63%, which correlate closely with those predicted theoretically after kinematic and dynamic optimisation. The introduction of a velocity cam function is shown to improve the dynamic quality indicators further and results in an overall reduction in peak-to-peak torque demand of 85%.