磁流变Stewart隔振平台H_∞半主动控制研究

Research on H_∞ Semi-active Control of Magnetorheological Stewart Vibration Isolation Platform

为改善星箭界面低频振动环境,采用磁流变阻尼器作为半主动控制元件,设计六杆Stewart隔振平台,替代原有锥壳过渡支架。采用牛顿-欧拉法建立整星隔振平台动力学模型。针对星箭界面低频振动环境在特定频段振动量级较大的特点,采用H_∞控制进行控制器综合,通过选择合适的加权函数,对特定频段振动进行重点衰减。磁流变阻尼器采用双sigmoid模型,并设计新型半主动控制策略,跟踪期望阻尼力。仿真结果表明,相对传统控制方法,H_∞半主动控制在特定频段减振效果较好,且在其他频段控制效果没有恶化,验证了算法的有效性。

To improve the interface vibration environment of satellite and the rocket,a six-pole vibration isolation platform is presented,using magnetorheological(MR)damper as semi-active control device.The dynamic model of the satellite vibration isolation platform is established by using the Newton-Euler method.In order to focus on the specific frequency band attenuation,the H_∞ control is used to integrate the controller.By selecting the appropriate weighting function,the vibration of a particular frequency band is attenuated.The MR damper adopts double sigmoid model,and a novel semi-active control strategy is designed to track the desired damping force.Based on the system model and controller,control system simulation is researched.The simulation results show that H_∞ semi-active control is better than the traditional control method,and the control effect is not deteriorated in other frequency bands.The effectiveness of the algorithm is verified.