In real-time hybrid testing, systems are separated into a numerically simulated substructure and a physically tested substructure, coupled in real time using actuators and force sensors. Actuators tend to introduce spurious dynamics to the system which can result in inaccuracy or even instability. Conventional means of mitigating these dynamics can be ineffective in the presence of nonlinearity in the physical substructure or transfer system. This paper presents the first experimental tests of a novel passivity-based controller for hybrid testing. Passivity control was found to stabilize a real-time hybrid test which would otherwise exhibit instability due to the combination of actuator lag and a stiff physical substructure. Limit cycle behaviour caused by nonlinear friction in the actuator was also reduced by 95% with passivity control, compared to only 64% for contemporary methods. The combination of passivity control with conventional methods is shown to reduce actuator lag from 35.3 degrees to 13.7 degrees. A big advantage of passivity control is its simplicity compared with model-based compensators, making it an attractive choice in a wide range of contexts.

中文翻译：

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非线性实时混合测试的无源控制

在实时混合测试中，系统被分成数值模拟的子结构和物理测试的子结构，并使用致动器和力传感器实时耦合。执行器往往会向系统引入虚假动态，这会导致不准确甚至不稳定。在物理子结构或传输系统中存在非线性的情况下，减轻这些动态的传统方法可能无效。本文介绍了用于混合测试的新型基于无源控制器的首次实验测试。被动控制被发现可以稳定实时混合测试，否则由于执行器滞后和刚性物理子结构的组合而表现出不稳定性。通过被动控制，由执行器中的非线性摩擦引起的极限循环行为也减少了 95%，相比之下，当代方法只有 64%。被动控制与传统方法的结合显示出将执行器滞后从 35.3 度减少到 13.7 度。与基于模型的补偿器相比，无源控制的一大优势在于其简单性，使其在广泛的环境中成为有吸引力的选择。