基于实时混合试验误差累积规律的时滞影响修正方法

为减小实时混合试验中的时滞影响，通常要对数值子结构计算得到的控制指令进行在线时滞补偿。为了保障实时性，要求作动器的负载不宜过大并处于最佳的性能区间。由于大比尺实时混合试验中物理子结构负载较大，对控制系统和作动器性能都提出较高的要求。此外，目前时滞补偿算法是无法完全消除时滞影响的，也即，时滞普遍存在于实时混合试验中且无法避免。针对上述问题，基于双显式数值积分算法的误差累积规律，该文提出了一种可以在试验后对试验结果进行修正以消除时滞不利效应的方法。分析了时滞对于实时混合试验结果的影响，对较大时滞情况下，尽管系统稳定，但可能得到“错误”的试验结果；通过理论推导，证明提出方法的合理性和适用性；通过4种实时混合试验工况的模拟，验证物理子结构分别为线性刚度、线性阻尼、非线性刚度及非线性阻尼构件的时滞修正效果。结果表明:所提出的方法可以显著降低时滞对于试验结果的影响；该方法对试验中时滞补偿效果不理想的情况，可以对位移、速度和加速度结果进行修正。

A POST-CORRECTION METHOD FOR THE INFLUENCE OF TIME DELAY IN REAL-TIME HYBRID SIMULATION BASED ON THE ERROR PROPAGATION OF NUMERICAL INTEGRATION ALGORITHM

The time delay effect in a real-time hybrid simulation (RTHS) is basically compensated through the compensation of the displacement command calculated by the numerical substructure, then the compensated command is sent to the actuator to vanish the delay. In RTHS, the loading is generally small related to the capacity of the actuator to keep the performance of actuator in a relatively ideal range. This also limits the conduction of large-scale RTHS. Due to the large loading, higher requirements are put on the control system and actuator of RTHS. Moreover, the state-of-art time-delay compensation method cannot eliminate the effects of time delay completely. For the problems mentioned above, this study proposed a method that can reduce the influence of the time delay after an RTHS. This method is based on the error propagation of the dual explicit numerical integration algorithm. To illustrate the method proposed in this study; it analyzed the effect of time delay on the RTHS results and in some cases with a large time delay, the time delay may cause results to be almost completely "wrong"; it gave the theoretical derivation process of the method proposed; it performed simulation verification in four cases when the physical substructures are linear stiffness, linear damping, nonlinear stiffness and nonlinear damping, respectively. The results show that: the method proposed can restore test results according to the error propagation of the dual numerical integration algorithm, reduce the errors caused by the time delay. In the case that the effort of delay compensation is not satisfactory due to the limitation of the test equipment, the method can simultaneously correct the displacement, velocity and acceleration results after the test.