适用于力反馈的三圆盘磁流变液执行器工作机理及建模

Working principle and modeling of three-plate magnetorheological fluid actuator for force feedback

为了提高磁流变液执行器力学模型的精度,建立了适用于电流随机变化且包含磁滞特性的三圆盘磁流变液执行器的分段线性力矩-电流模型.分析了执行器的工作原理,推导了基于Bingham塑性模型的力矩公式.磁路由铁磁物质和磁流变液组成,说明了这2种物质的磁特性,分析了铁磁物质中存在磁滞以及在磁流变液中观察不到磁滞的原因.铁磁物质的磁滞特性影响了执行器的力矩-电流特性,实验表明力矩和电流之间存在磁滞.当电流变化过程为0-1.2-0 A时,不包含磁滞特性的二次多项式模型的残余标准差分别为8.2和11.2 N.mm,分段线性模型的残余标准差分别为5.9和6.2 N.mm,分段线性模型的精度比较高.

To improve the accuracy of a magnetorheological-fluid （MRF） actuator mechanical mod- el, considering hysteresis, a piecewise linear torque-current model of a three-plate MRF actuator suit- able for random current change is established. The working principle of the actuator is analyzed, and a torque formula based on the Bingham plastic model is derived. The ferromagnetic material and MRF form the magnetic circuit, and their magnetic properties are introduced. Reasons of hysteresis being in the ferromagnetic material and no hysteresis observed in the MRF are studied. Hysteresis of the ferromagnetic material affects the torque-current relationship of the actuator, and the experimental results show that the hysteresis phenomenon exists between the torque and current. With the current sequential variation of 0-1. 2-0 A,the residual standard deviation of the quadratic-multinomial model without considering hysteresis is 8.2 and 11.2 N·mm, respectively, and the residual standard devia- tion of the piecewise linear model is 5.9 and 6. 2 N· mm, respectively. The piecewise linear model is more accurate than the quadratic-multinomial model.