一种无传统防扭力臂的直升机旋翼操纵机构位置解分析

Displacement Analysis of a New Type of Helicopter Rotor Control Mechanism without Traditional Non-rotating Scissor

直升机旋翼操纵机构是一种比较复杂的混联机构,此类混联机构的整机精准运动学全解研究尤为重要。提出一种新型的旋翼操纵机构,该机构采用一种2SPS+RPU+PS机构作为并联驱动模块,从而省去了传统机构中的防扭力臂,以该机构为例给出了此类旋翼操纵机构的位置解全解。首先,分析了旋翼操纵机构约束力/矩,计算了其自由度。其次,通过理清机构中的几何和尺寸约束关系,得到了机构的约束方程。通过约束方程建立起桨距角和旋转倾斜盘位姿参数的耦合关系,结合Sylvester消元法得到了求解旋转倾斜盘位姿的解析模型,进而得到整体机构的运动学反解。再次,采用消元法求解了2SPS+RPU+PS机构的位置正解封闭解,通过上层机构的运动传递关系,得到了三个桨距角的表达式,从而完成了整体机构正解分析。最后,给出机构在一般位形下的位置解算例,实现了旋翼操纵机构的位置正反解精准求解。该研究为旋翼操纵机构的位置解研究提供了参考。

The helicopter rotor control mechanism is a type of relatively complex hybrid mechanism,and the research on the complete kinematics of this type of hybrid mechanism is particularly important.A new type of helicopter rotor control mechanism is proposed,which uses a 2SPS+RPU+PS mechanism as a parallel driving module,eliminating the non-rotating scissor in traditional mechanisms.Taking this mechanism as an example,a complete solution to the displacement of this class of control mechanism is provided.Firstly,the constraint forces/torques of the control mechanism is analyzed,and its degree of freedom is calculated.Secondly,by clarifying the geometric and dimensional constraints in the mechanism,the constraint equations of the mechanism are obtained.The coupling relationship between the pitch angles of three blades and the pose parameters of the rotating swashplate is established through constraint equations.Combined with the Sylvester elimination method,an analytical model for solving the pose of the rotating swashplate is obtained,and then the inverse displacement of the overall mechanism is obtained.Once again,the closed form solution of the forward displacement of the 2SPS+RPU+PS mechanism is solved using the elimination method.Through the motion transmission relationship of the upper mechanism,the pitch angles of the three blades are obtained,and thus the forward displacement of the overall mechanism analysis is completed.Finally,an example of the displacement analysis of the mechanism in a general configuration is provided,achieving accurate solutions of the forward and inverse displacement of the control mechanism.This study provides a reference for the displacement research of helicopter rotor control mechanisms.