摘要
为克服转台低速运动时摩擦力测量不准确的缺点,设计了具加速度计的摩擦力测量系统以实现精确测量。利用加速度计测量的启动加速度,获得伺服转台的所需驱动力矩,利用霍尔传感器获得驱动电流,获得电机的总的驱动力矩,从而获得伺服转台的干扰力矩。测量中转矩纹波对摩擦力的测量影响巨大,其主要由机械及电气因素引起,具有周期性特征,设计了数字滤波器误差滤除,获得摩擦力矩的有效值,进而采用非线性最小二乘拟合出摩擦力矩的Stribeck参数,最后在光电设备转台中实验。结果表明,将测量得摩擦力矩加入原有伺服转台模型中,正弦引导时,可准确表现出转台位置秃顶及速度反向"0"速点不连续的现象,仿真与实验的速度误差有效值为0.044°/s,相关系数达0.990 9,位置误差有效值为0.026 5°,相关系数达0.995。该测量系统及方法可有效精确测量出伺服转台的Stribeck摩擦力矩,该测量方法亦可用于其他光电设备摩擦力矩测量。
In order to overcome the shortcoming that friction measurement is not accurate when the servo table moves at low speed,a measurement system of friction with accelerometer is designed to achieve accurate measurement.The start toque of servo table can be acquired using start accelerate which measured by accelerometer,drive current is also obtained using hall element,and the total toque of the motor can be got,then disturbance toque of servo table can be obtained,the toque ripple have a huge impact on friction measurement.The toque ripple is mainly caused by mechanical and electrical factor,and it has periodicity characteristic,the digit filter is designed to filter error which is caused by toque ripple,then the virtual value of friction toque can be acquired,then the parameter of friction toque can be obtained using nonlinear least squares method.The experiment is carried out on the optoelectronie device.The experiment results shows：the measurement friction is added to actual systems,when the system is guided with sine curve,the phenomenon of position bald and discontinuous ＂0＂velocity,the effective value of velocity error between experiment and simulation is 0.044°/s,the correlation coefficients can reach to 0.990 9,the effective value of position error is 0.026 5°,the correlation coefficients can reach to 0.995.This measurement system and method can effectively and accurately measure friction toque of servo table,and this can be used in measurement of friction toque on other optoelectronic device.
出处
《电子测量技术》
2013年第11期92-97,共6页
Electronic Measurement Technology
