三自由度冗余驱动飞行模拟器设计及分析

摘要

A three-degree-of-freedom (3-DOF) rotational redundant-actuation flight simulator is proposed.It includes three degrees of freedom,six actuators and 3 redundant actuators.Based on the 3-DOF RRR spherical parallel manipulator,the parallelogram mechanism is introduced to accomplish the redundant actuation so that the flight simulator can be manipulated by enough power.The use of the parallelogram mechanism improves the stiffness and overcomes the drawback of the low power of an electric motor compared with hydraulic power.The parameters of 3-DOF spherical parallel manipulator are changed to gain the smallest volume of the manipulator of the flight simulator relatively.Direction-cosine is built with the analytically spherical theory;then the Jacobian matrix is established based on the direction-cosine.The inverse kinematics is solved with the constant intersection angle principle and the constraint equations are established at the same time.The interference that limits the input angles of the parallelogram mechanism is considered,so that the ranges of input angle are gained by the cross vector product theorem.Based on the range of input angles,an effective numerical algorithm of forward kinematics and inversely kinematical equations and the workspace volume are obtained.The results show that the volume of flight simulator proposed in this paper is apparently larger than the Stewart parallel manipulator.%提出一种三转动自由度冗余驱动飞行模拟器.在3-RRR球面并联机构的基础上,通过球面平行四边形机构的引入而实现冗余驱动,从而克服电机驱动相对于液压驱动功率相对较小的缺点.将一般3-RRR球面并联机构的参数进行变化,从而设计出体积相对较小的运动机构.利用空间球面解析理论建立了各支链的方向余弦,在方向余弦建立的基础上给出机构的雅可比矩阵.利用支链夹角不变原理建立了机构的约束方程,进行了运动学反解分析.考虑球面平行四边形冗余驱动支链的干涉情况,根据向量叉积定理计算得出了输入转角范围,并通过一种数值正解算法计算得到机构给定输入参数的工作空间.分析结果表明,在给定特定结构参数的情况下,所提出的飞行模拟器具有转角大的优点,远远大于传统的Stewart机构,从而为飞行模拟器的实际应用提供一种新的选择.