电机电流控制的电动冲击扳手定扭矩研究

Exploring Constant Torque of Electric Impact Wrench Controlled by Motor Current

针对电动冲击扳手在紧固螺栓时存在输出转矩波动较大的问题,提出了基于电流参数的电动冲击扳手定扭矩控制策略。首先,通过信号采集系统同步采集扳手在紧固螺栓过程中的输出扭矩信号和电机电流信号,并利用SG(Savitzky-Golay)滤波器对信号中的噪声进行降噪处理。然后结合多项式曲线拟合建立了扳手输出扭矩与电机电流的多项式模型关系,结果表明扳手输出扭矩与电机电流之间为3阶多项式关系。最后通过实验平台进行验证分析。实验结果表明,在该控制策略下,可实现通过控制电机电流来对扳手进行定扭矩控制,并且控制误差小于4%,提高了电动冲击扳手定扭矩控制系统的控制精度和鲁棒性。

The large output torque fluctuation during the electric impact wrench fastens bolts. Therefore, the paper proposes a torque control strategy of the electric impact wrench based on current parameters. Firstly, the experiment uses the signal acquisition system to synchronously collect the output torque signal and motor current signal of the wrench in the process of fastening bolts. The SG(Savitzky-Golay) filter was used to reduce the noise in the signal. Then, the paper uses the polynomial curve fitting to establish the polynomial relation between wrench output torque and motor current. The results show that the relation between the output torque of the electric impact wrench and the motor current is a third-order polynomial relation. Finally, experiments are carried out to verify the results. The experimental results show that the torque control of the electric impact wrench is achieved by controlling the motor current and that the control error is less than 4%, thus improving the control accuracy and robustness of the electric impact wrench torque control system.