空间RSSR机构的装配偏差区间分析

Assembly deviation interval analysis of spatial RSSR mechanism

针对空间RSSR曲柄摇杆机构装配偏差分析问题,首先基于区间分析法和三角模糊数的概念建立了包含间隙和杆长尺寸偏差变动信息的区间模型,构建了偏差回路和非线性区间参数方程组,并对非线性区间参数方程组进行了求解。其次,对空间RSSR机构进行了运动仿真,得出了输出角的名义数据,并与非线性区间参数方程组的求解结果进行对照,绘制出了角位移曲线及不同隶属度情形下的角位移偏差对比曲线。最后,分析了关节处间隙变动和杆长偏差对机构输出角位移偏差的影响。分析结果表明:在机构输出角位移曲线的极小值与极大值点附近,间隙与杆长的变动对输出角位移偏差的影响较显著,且间隙与杆长误差越大,角位移偏差受到影响也越大;调整隶属度数值至合适数值,机构输出角位移偏差有明显改善。

Aiming at the assembly deviation analysis problem of spatial Revolute-Spherical-Spherical-Revolute(RSSR)crank-rocker mechanism,the interval models including gap deviation and rod length deviation were established based on interval analysis and triangular fuzzy number.The deviation loop and nonlinear interval parameter equations were constructed,and the equations were solved.The motion simulation of spatial RSSR mechanism was carried out,and the nominal data of output angle was obtained.Compared with the results of nonlinear interval parameter equations,the angular deviation curve and comparison curve of angular deviation under different membership value were drawn.The influence of the joint clearance variation and the rod length deviation on output angular displacement deviation of the mechanism was analyzed,and the analysis results showed that the deviation of clearance and rod length had a significant impact on the output angular displacement near the minimum and maximum points of the output angular displacement curve.The larger the deviations of joint clearance and rod length were,the greater impact on the output angular displacement deviation was.The output angular displacement deviation of the mechanism was significantly decreased by adjusting the membership value to a suitable value.