单自由度八杆仿生机构构型与尺度同步设计方法

Integration Design Method of Configuration and Dimension for One DOF Eight-bar Bio-inspired Mechanism

单自由度八杆仿生机构杆长参数较多,是仿生机器人领域研究的难点之一。为提高设计效率,提出一种构型与尺度同步设计方法。在选定的运动链和机架的基础上,以不等式形式分步给出运动可行性及外形约束条件,使得上一步的杆长可作为下一步求解的已知值。通过该过程,在得到八杆仿生机构构型的同时,快速得到所有杆长的初步可行域。循环上述过程,逐步缩小约束条件的范围,可使得八杆机构的杆长快速接近目标值。在此基础上,分类讨论了连杆搭接顺序、约束条件及基本运动链的差异对求解难度及构型结果的影响。利用所提出的单自由度八杆仿生机构的设计方法,在对初始条件进行合理选取的前提下,可在初步得到构型的同时将杆长限定在较小范围内,实现了构型与尺度的同步设计。该方法还可应用于其他单自由度机构的设计当中,具有较好的借鉴意义。

The one DOF eight-bar bio-inspired mechanism has many link length parameters and is difficult to design, which is the difficulty of research in the field of bio-inspired robots. In order to improve the design efficiency, an integration design method of configuration and dimension is proposed. On the basis of the selected kinematic chain and frame, the movement feasibility and shape constraint conditions are given step by step in the form of inequalities, so that the link lengths of the previous step can be used as the known value of the next step. Through this process, while obtaining the configuration of the eight-bar bio-inspired mechanism, the initial feasible region of all link lengths can be quickly obtained. The above-mentioned process is cycled to gradually reduce the range of constraint conditions, so that the link lengths of the eight-bar mechanism can quickly approach the target values. Then the effect of links adding sequence, constraint conditions and the difference of basic kinematic chain on solving difficulty and configuration results is analyzed. By using the design method of the one DOF eight-bar mechanism, on the premise of reasonable selection of initial conditions, the initial configurations can be obtained and the lengths of the links can be limited in a small range, so that the integration design of the configuration and the dimension can be realized. This method can also be applied to the design of other one DOF mechanisms and has a good reference significance.