新型过约束正交并联六维力传感器测量模型与静态标定试验

面向航空航天领域对重载大吨位多维测力传感器的急需,通过引入冗余测力分支,提出一种适用于重载测力场合的新型过约束正交并联六维力传感器结构,在提高传感器结构刚度和承载能力的同时有效抑制了关节摩擦对多维力传感器测量精度的影响。基于螺旋理论,推导得到了该并联传感器一阶静力影响系数矩阵,建立理想状态下该新型过约束正交并联六维力传感器测量数学模型。考虑各测量分支的初始预紧力与刚度,基于传感器静力平衡方程与补充建立的位移协调方程,推导建立考虑初始预紧力与分支刚度因素下该新型过约束正交并联六维力传感器测量数学模型。在此基础上,设计并研制该新型过约束正交并联六维力传感器样机,搭建传感器加载标定与信号采集及处理试验系统,对新型过约束正交并联六维力传感器进行了加载标定试验。根据试验结果计算了传感器测量误差矩阵,分析得到了传感器测量精度,从而为重载过约束并联六维力传感器的开发与应用提供了参考。

Measurement Model and Calibration Experiment of New Over-constrained and Orthogonal Parallel Six-dimensional Force Sensor

The heavy load multi-dimensional force/torque sensors have become more needed in the fields of aeronautics and astronautics. By introducing redundant load branch, a suitable for heavy load occasions of new over-constrained and orthogonal parallel six dimensional force sensor structures is designed and developed to improve the sensor structure stiffness and bearing capacity, at the same time can effectively restrain the influence of joint friction on the multi-dimensional force sensor measurement accuracy. Based on screw theory, the order static effect coefficient matrixes of the sensor is derived, establish the mathematical model of sensor which under ideal conditions. Considering the initial pre-tightening force and stiffness of measuring branch, based on the static equilibrium equations and displacement compatibility equations, mathematical model for calibration is deduced. The six-dimensional force sensor was manufactured, set the load calibration and signal acquisition and processing experiment system, on the basis of the developed prototype of new over-constrained、orthogonal parallel six dimensional force sensor and the static calibration is performed. To calculate the sensor measurement error matrix, according to the analysis of experimental results obtained measurement accuracy. The study provides reference for the development and application of the overload and over-constrained and orthogonal parallel six-dimensional force sensor.