Dynamics and Chaos Intensity Analysis of Under-Actuated Mechanism by Uniformity and Particle Swarm Optimization

Generally, nonlinear systems have dynamic uncertainties, and under certain conditions, the systems exhibit different chaos intensities. Therefore, it is an important consideration for designers to realize the suppression and enhancement of chaos intensity under nonlinear factors according to the actual situation, but there are few research results on this problem. To investigate the dynamic performance and chaotic intensity of a nonlinear mechanism, a planar closed-chain under-actuated mechanism, which has not been extensively studied before, is taken as an example. It is worth noting that a small change in the parameters of a nonlinear system will cause a large change in the motion state of the system and even the mutual transformation between chaotic phenomena and periodic phenomena. To solve this problem, uniformity is used to evaluate the chaos intensity of the system. Finally, based on uniformity, the particle swarm optimization algorithm successfully achieves the suppression and enhancement of the chaos intensity of the closed-chain under-actuated five-bar mechanism by optimizing its linkage length and driving speed, and the results are verified by the experimental platform.