摘要
目前国外先进的电动执行器都具有力矩关断功能,当执行器出现堵转时,可以有效减少过大的输出力矩对阀门造成的损坏。力矩关断功能的关键问题是能够精确检测出力矩,采用传感器方法虽然较为简便,但是对安装空间有要求,还提高了成本,降低了系统的可靠性以及执行器的寿命。针对这个问题,提出一种软件检测实时力矩的方法。采用与电机参数无关的力矩数学模型,以避免参数变化对力矩测量的影响;通过检测电机的电压和电流来计算电机的定子磁链,再根据定子磁链来计算实时力矩,以提高计算精度;采用反馈补偿的方法来消除定子磁链计算过程中由于纯积分运算所产生的发散问题;采用选取多组力矩计算结果进行曲线拟合再平均的方法,解决执行器内部的蜗轮蜗杆对电机转速和力矩耦合较大的问题。针对2台不同功率等级的电动执行器进行力矩测量的标定实验。实验结果表明,在负载变化的条件下,无论执行器运行于高速还是低速,该方法都可以实时准确地测量出力矩,从而验证了所提方法的有效性和可行性。
Currently, the superior electric actuator has the ability of torque-off, which will highly reduce the dam-age caused by excessive torque in the case of locking .Precise detection of torque is the key issue of the ability .It is simple to detect the torque by sensor, however, the sensor needs installation space and it will increase the cost, and also it will reduces the reliability and decrease the life of actuator.To solve the problem, this paper proposes a software method to detect torque in real-time .To eliminate the influence from parameter variation a mathematical model irrelevant to motor parameters is built up .Also, to improve calculation precision, motor voltage and motor current are detected for stator flux calculation , and then the real-time torque is calculated accordingly .The diver-gence caused by pure integral operation is eliminated by feedback compensation during flux calculation process . Several groups of torque detection result are processed by curve fitting and then averaged afterward to solve the problem of severe coupling between worm gear, motor speed and torque.The experiments for torque calibration are performed on two electric actuators with different rated power .The experiment results show that the real-time torque can be detected precisely even under variation loads , whenever the actuator operates in high speed or low speed , so the effectiveness and the feasibility of the proposed approach is proved .
出处
《电子测量与仪器学报》
CSCD
北大核心
2015年第3期415-426,共12页
Journal of Electronic Measurement and Instrumentation
关键词
电动执行器
定子磁链
反馈补偿
力矩检测
electric actuator
stator flux
feedback compensation
torque detection
