National Key laboratory on Aircraft Fight Control, School of Automation Science and Electrical Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel). 2018 Nov 20;18(11):4050. doi: 10.3390/s18114050.
The aircraft full-scale fatigue test is widely used in the modern aircraft industry for the safety of flight. Generally, the aircraft full-scale fatigue test is achieved by structural loading; multiple hydraulic actuators are used to apply load for force control. The fatigue loading test takes approximately several years. A key challenge is how to accelerate the loading frequency to shorten the total test time. Nevertheless, when pluralities of hydraulic actuator simultaneously increase the loading frequency, the mutual coupling force from the low rigidity of the aircraft structure will cause a large loading error, meaning that the test cannot be implemented. Although it is possible to reduce error by adding sensors, the force sensors need to connect several kilometers of cable. This paper proposed a novel motion synchronous composite decoupling control strategy with fewer sensors. The control method compensates the negative coupling effect of the channels by integrating the command signals and feedback signals of all channels. It can suppress coupling force and reduce errors at higher frequencies, thereby shortening the experiment time. Opposed to traditional decoupling control methods, advantages of this strategy are that it only needs force sensors and it does not need additional displacement or velocity and acceleration sensors to collect state variables for building the state space. Furthermore, it has been experimentally verified that the new motion synchronous composite decoupling control method can indeed guarantee sufficient control accuracy when the test frequency is increased. The method has great economic significance for shortening test duration.
飞机全尺寸疲劳试验在现代飞机工业中被广泛应用于飞行安全。通常，飞机全尺寸疲劳试验通过结构加载来实现；为了进行力控制，会使用多个液压作动器施加负载。疲劳加载试验大约需要几年时间。一个关键的挑战是如何提高加载频率以缩短总测试时间。然而，当多个液压作动器同时增加加载频率时，由于飞机结构的低刚性，相互耦合力会导致较大的加载误差，这意味着测试无法进行。虽然可以通过添加传感器来减小误差，但力传感器需要连接数公里的电缆。本文提出了一种新颖的运动同步复合解耦控制策略，该策略使用的传感器较少。该控制方法通过整合所有通道的指令信号和反馈信号来补偿通道的负耦合效应。它可以在更高频率下抑制耦合力并减小误差，从而缩短实验时间。与传统的解耦控制方法相比，该策略的优点在于，它仅需要力传感器，并且不需要额外的位移或速度和加速度传感器来收集状态变量以构建状态空间。此外，实验验证了新的运动同步复合解耦控制方法确实可以在提高测试频率时保证足够的控制精度。该方法对于缩短测试时间具有重要的经济意义。
