Dimension collaborative optimization design of a multi-closed-loop space deployable mechanism

This paper presents a new multi-closed-loop space deployable mechanism. The position analysis of the deployable mechanism has been carried out based on the loop constraint equations. Then, under the premise of the given aperture diameter and the range of opening angles, the mathematical model of dimension optimization of the deployable mechanism is established, in which the design variables are bar lengths, and the objective functions include maximizing the expansion ratio and the minimal transmission angle, and minimizing the driven stroke. By the collaborative optimization method, the optimization problem is divided into two levels: a system level which is used to coordinate the inconsistency of the coupling variables in subsystems, and three parallel subsystems which are used to minimize the difference between the optimization scheme of subsystems and the goal of the system level. The dimension parameters of deployable mechanisms can be optimized through the established collaborative optimization model. Simulation results show that the deployment process is smooth without the dead points when the expansion ratio, the driven stroke and the minimum transmission angle are 15∶1, 198mm and 22°, respectively.