结构试验闭环补偿控制技术初探
A Preliminary Study on Closed-loop Compensation Control for Structural Test

飞机结构强度试验受外界条件作用较明显，试验误差可能发生较大变化。强度试验采用的经典PID控制器，该控制器对误差控制能力有限，难以有效降低试验控制误差。为了解决这个问题，提出一种闭环补偿控制技术。在对控制参数优化技术、PID自适应技术及开环补偿控制技术研究的基础上，深入分析了外界因素对试验的影响机制，设计了一种闭环补偿控制算法，此算法可以根据试验精度的变化控制器输出信号进行实时补偿。补偿控制算法可能导致试验控制系统出现稳定性的问题，所以利用赫尔维茨稳定性判据对该方法的稳定性进行了证明。同时设计了两个结构试验工况对本方法进行物理验证。试验结果表明：本文控制方法对于改善试验控制精度是合理有效的，并在将来有更为广泛的应用价值。
Aircraft structural test is affected greatly by the environmental conditions, so that testing control error may be changed largly. The traditional PID controller cannot control testing error effectively. To solve the problem, a closed-loop compensation control technique is developed. Based on the control parameter optimization technique, PID self-adaptive technique and open-loop compensation control scheme, the effect mechanism of environmental conditions was analyzed. A closed-loop compensation control algorithm was designed. Using this control algorithm, the output signal of controller can be compensated in real time to decrease the environmental effect, and the loading system can be controlled precisely. On the other side, the closed-loop compensation control technique may result in system instability, so Hurwitz stability criterion was used to verify the stability of this method. In order to validate the method, two test setups were designed and the verification experiments were perofrmed. The results showed that the present method was effective and reasonable to improve the testing control accuracy, and could be widely used in relevant tests in the future