机械

针对电动冲击扳手在紧固过程中扭矩难以测量以及实现精确控制的问题，提出利用测量冲击次数来实现定扭矩控制的控制方法。首先，建立冲击次数与螺栓受压数据采集平台，采集每次冲击过程中的螺栓受压情况，并将采集数据进行小波阈值去噪处理。然后，将处理后的数据通过经验公式转化成扭矩值，将每次冲击后得到的扭矩值进行逐个对应，建立非线性关系模型。最后，设计控制系统实现定扭矩控制，并通过实验平台验证扭矩控制精度。实验表明，可以通过采集扭矩的冲击次数来实现定扭矩控制，并且控制误差在1%以内，控制精度随着扭矩的增大而变小。由此实现了电动冲击扳手定扭矩控制。

Aiming at the problem that it is difficult to measure the torque and realize the precise control during the tightening process of electric impact wrench, a control method to realize the fixed torque control by measuring the number of impacts is proposed. Firstly, a data collection platform for the number of impacts and bolt pressure is established, the bolt pressure during each impact process is collected, and the wavelet threshold denoising of the collected data is conducted. Then, the processed data is converted into torque value through the empirical formula, and a nonlinear model is established corresponded to the torque value obtained after each impact. Finally, the control system is designed to realize the fixed torque control, and the torque control accuracy is verified by the experimental platform. The experiments show that the fixed torque control can be realized by collecting the number of the impacts of the torque, and the control error is within 1%, and the control accuracy decreases with the increase of the torque, which realizes the fixed torque control of the electric impact wrench.