由于存在加工误差等因素,可展机构各连杆实际加工长度与理论计算长度往往不同,需要在装配时对其调整。多环闭链可展机构具有闭环多、环约束互相耦合、参数关系复杂等特点。为解决在尺寸调整时存在的高非线性、强耦合等问题,以均方根形式定义多环闭链机构的综合调整量,并以调整结构势能最小作为目标函数,推导出多环闭链可展机构尺寸调整的基本数学模型。根据实际调整方式,提出单向调整和双向调整两种计算模型。在此基础上,对多构态下多环闭链可展机构的尺寸调整方法进行研究。通过算例对上述方法和模型进行验证。结果表明,利用该方法得到的调整结果能满足可展机构多构态、多约束、多种调整方式的要求。研究成果有助于降低多环闭链可展机构的装配和加工难度。
Due to the fact of manufacturing error,the realistic length of the linkages of the deployable mechanisms is always different from the theoretical one. It occurs the adjustment of linkages when assembling. The multi-closed-loop deployable mechanisms have the characteristics of many of closed loops,coupling of loop constraints and complication of parameters. In order to solve the problem of high nonlinear and tight coupling during the size adjustment of these mechanisms,the complex adjustment amount of the multi-closed-loop mechanisms is defined by root-mean-square algorithm. Aimed to minimize the adjustment potential energy,the basic size adjustment model of the multi-closed-loop deployable mechanisms is derived. According to the mode of the adjustment in practice,the unidirectional and bidirectional computation model is proposed. Based on that,the adjustment method of the multi-closed-loop mechanisms in the multi-configuration is investigated. The above method and models are verified by the examples. The results demonstrate that the calculated models satisfy the demands for multi-configuration,multi-constraint and multi-adjustment. The achievement will help to reduce the difficulty of assembling and manufacturing of the multi-closed-loop deployable mechanisms.