基于PIC单片机的数显扭矩扳手控制系统设计

Design of digital display torque wrench control system based on PIC MCU

针对传统机械扳手在扭矩控制方面存在的精度低、可靠性差等问题,设计并实现了一种数显扭矩扳手控制系统。以外围接口控制器(PIC)单片机为核心,通过脉宽调制(PWM)波脉冲调试驱动H桥型电机驱动电路,采集电机运转中的电流和转速信号构建数学模型,并使用滑动加权平均滤波算法消除采集信号中随机噪声的干扰,以提高采集精度,实现对扭矩的精确控制。实验结果表明:在1200~3000 N·m扭矩范围内,控制系统可达到±5%的扭矩控制精度,且运行稳定、可靠,具有很高的实用价值。

Aiming at the problems of low precision and poor reliability in torque control of traditional mechanical wrench,a digital display torque wrench control system is designed and implemented.The control system is based on peripheral interface controller(PIC)micro controller unit(MCU).By adjusting the drive circuit of H-bridge motor with PWM wave pulse,current and rotating speed signals in motor running are collected to build mathematical model,and the sliding weighted average filtering algorithm is used to eliminate the interference of random noise in the collected signals so as to improve the acquisition precision and realize the precise control of torque.The experimental results show that in the range of 1200~3000 N·m,the control system can achieve±5%torque control precision,and the operation is stable and reliable,it has high practical value.