Accuracy analysis of a multi-closed-loop deployable mechanism

Abstract

The multi-closed-loop deployable mechanism generates distortion which is caused by the deviation of each rod after being assembled as a result of manufacturing error, which leads to the degradation of the antenna performance or excess of the given envelope. The multi-closed-loop deployable mechanisms consist of many closed loops and have complicated topology structure and loop constraints coupling. The positioning accuracy analysis of such mechanism is more difficult than the open-chain mechanisms or the single-loop mechanisms. In order to solve this problem, first, based on the minimum of elastic deformation energy, the distortion analysis model is constructed. Second, the sensitivity of the mechanism distortion to the individual rod deviation is investigated by examining the Lagrange multipliers. By means of this model, the allowable tolerance of multi-closed-loop deployable mechanism is discussed and calculated. Last but not least, the above method and model are applied to the four-closed-loop deployable mechanism to solve the problems of its distortion, sensitivity, and tolerance in both fully deployed and folded configurations. It is demonstrated in this paper that the model and method proposed are well accommodated to the accuracy analysis of such mechanisms. The achievement of the research will help reduce the difficulties of the assembling and manufacturing of the multi-closed-loop deployable mechanisms.

Link adjustment for spatial multi-loop deployable structures considering redundant constraints based on multi-objective discrete optimization

“…Yang et al. 7 reported a new concept—“comprehensive adjustment amount”—as an objective function and utilized the optimization method to perform an accuracy analysis for the ESS. Based on this model, the researchers implemented a sensitivity evaluation and tolerance allocation.…”

An optimum design method for a new deployable mechanism in scissors bridge

“…In the area of optimization design for deployable mechanism, many research works have been conducted. 10–21 Zeng et al. 10 established a parameter optimization model of the bridge expanding device and bridge sections based on the virtual prototyping technology, the optimization design of the device is further carried out by the limit loads of hydraulic cylinders; however, it did not consider the practical situation of the difference between pushing force and pulling force.…”

“…With regard to the research focusing on how to reduce the error caused by deployable structure, Yi et al. 16 made an accuracy analysis of a multi-closed-loop deployable mechanism involving manufacturing error and distortion, Zhao et al. 17 conducted a study on spatial multiloop deployable structures to ensure accurate performance and deployable reliability with multiobjective discrete optimization.…”

Deployment accuracy analysis of cable-strut deployable mechanism with joint clearances and forces constrained

“…Plenty of researchers have been devoted to studying the influence of joint clearance. Most of the studies concentrated on single-loop linkage [15][16][17][18][19][20], but the common deployable mechanisms are multi-loop linkages that have loop constraints coupling and complicated topology structure [21,22]. The analytical method used in single-loop linkage may not be applicable to it on account of challenges of highly nonlinear and strong coupling.…”

“…The analytical method used in single-loop linkage may not be applicable to it on account of challenges of highly nonlinear and strong coupling. Few achievements have been obtained on accuracy analysis of multi-loop linkage with joint clearances to be considered, Yang Y et al [22] have analysed the relationships between distortion of whole mechanism and deviation of each rod based on the minimum of elastic deformation energy and Lagrange multiplier method, but the influence of joint clearance has not been considered. Ding J. and Wang C. [23] have decoupled the multi-loop mechanism with joint clearances based on matrix method and particle swarm optimization, but they only have investigated the maximum deployment error.…”