基于转速转矩双闭环的液黏调速控制方法研究

液黏风扇调速系统存在滞环、死区、饱和区等多种非线性特性,在调速过程中,其输入输出关系曲线存在最大可达44%的滞环和大约为43%的死区,非线性度最大可达30%。设计了转速-转矩双闭环模糊控制策略:结合Stribeck摩擦理论,按照稳态曲线的分段线性规律将控制过程分段,获得模糊控制表;基于扩展卡尔曼滤波环节修正转矩测量值,从主动轴与从动轴之间的转矩传递关系分析输出转速变化规律,并进行试验验证。结果表明:相比于PID控制策略,所提出的控制策略将转速误差降低了75%,滞环减小至小于11%,消除死区,拓宽控制电压输入范围,有效改善了系统稳态调速过程中表现出的非线性滞环和死区现象。

Research on Hydro Viscous Speed Regulation Control Method Based on Speed Torque Double Closed Loop

The hydro viscous fan speed regulation system features many nonlinear characteristics such as hysteresis, dead zone, saturation zone, and so on. Therefore, the input-output relationship curve has a hysteresis of up to 44% and a dead zone of about 43% during the speed control process. The maximum non-linearity may reach 30%. Aiming at the open-loop nonlinear phenomenon mentioned above. In this paper, a speed-torque double closed-loop fuzzy control strategy is designed: combined with Stribeck friction theory, the control process is segmented according to the piecewise linear law of the steady-state curve, and the fuzzy control table is obtained. Based on the extended Kalman filter, the torque measurement value is adjusted by the filter link, and the change rule of the output speed from the torque transmission relationship between the driving shaft and the driven shaft is analyzed. The test results show that compared with the PID control strategy, the proposed control strategy can reduce the speed error by 75% and the hysteresis to less than 11%. Moreover, the dead zone is eliminated, the control voltage is widened to the input range, and the nonlinear hysteresis and dead time phenomenon in the steady-state speed regulation process of the system are effectively improved.