Gain-Scheduled Vibration Isolation Control Using Semi-Active Actuator

研究了具有可变阻尼器机构的半主动执行器的模型，并建立了新的阻尼器模型，该模型的阻尼系数被可变气门机构线性地改变，其中伺服阀可以采用孔板开启率。我假设阀门的位移是由一个非线性弹簧限制的。将该阻尼器模型应用于车辆悬架，并引入了线性参数变系统，其中包括可变阻尼器模型。因此，我设计了增益预定控制系统，并通过仿真结果验证了所设计的控制器能够根据悬架的状态平滑地改变系统的阻尼系数，并将其应用于磁流变液阻尼器。将磁流变阻尼器的特性识别为输入电流与阻尼系数之间的关系。我把这个关系近似为行程速度的五分之一次方的函数。并设计了将输入电流加到磁流变阻尼器的控制系统，使磁流变阻尼器的阻尼器系数与所提出的增益调度控制器的输出一致。通过实验验证了该方法的有效性。此外，还验证了我设计的卡尔曼滤波器可以估计行程速度。我还研究了半主动控制系统在四自由度结构中的应用。针对降阶模型设计了所提出的控制系统。仿真结果表明，当阻尼系数变化范围较小时，该方法能有效地抑制振动。在变化范围变大的情况下，通过切换带冲程速度符号的控制器，找出了高阶振型的激励问题。

I have examined a modelling of a semi-active actuator with a variable damper mechanism and have constructed the new damper model whose damping coefficient is assumed to be linearly changed by the variable valve mechanism, where the servo valve can adopt the orifice open rate. I assume that the valve displacement is restricted by a nonlinear spring. The damper model has been applied to a vehicle suspension and I have introduced the linear parameter varying system involving the variable damper model. Thus, I have designed the gain-scheduled control system and it has been verified from simulation results that the damping coefficient is smoothly changed according to the state of the suspension and the proposed controller can perform the specified control.Furthermore, I have applied the proposed method to a Magneto-Rheologial fluid damper. The characteristics of the MR damper were identified as the relation between input current and damping coefficient. I approximated the relation as the function of the one fifth power of stroke velocity. And I have designed the control system that put the input current to the MR damper, so that the MR damper coefficient coincides with output from the proposed gain-scheduled controller. By carrying out experiments effectiveness of the proposed method has been verified. Also it has been verified that a Kalman filter I designed can estimate the stroke velocity.I have also examined application of the semi-active control system to a four-degree-of-freedom structure. I designed the proposed control system for the reduced-order model. It has been verified from simulation results that the proposed method can suppress the vibration when the variable range of damping coefficient is relatively small. I have found out excitation problem of the higher modes by switching of the controller with sign of the stroke velocity in case that the variable range becomes large.