Integrated Optimum Design of Structure and Servosystem in Information Processing Equipments

本研究提出了结构和伺服系统的优化设计方法，以实现更高的性能有关的定位和稳定性。该方法采用灵敏度分析和非线性规划相结合的方法，考虑了结构和伺服系统的综合优化设计。控制系统的性能指标通常表示为频域和时域特性。因此，本研究考虑两种类型的伺服系统，即一种是由动态补偿器如相位超前和相位滞后补偿器组成，以处理所需的频率特性，另一种是由LQI控制系统组成，其中控制器被设计为获得期望的瞬态响应。用有限元法建立了大自由度结构的初始空间模型。伺服系统的性能和稳定性取决于控制输入和输出信号之间的频响函数（FRF）的增益和相位特性等结构特性。本研究提出的整合式最佳化方法，可使闭环系统在高阶自然模态下具有更高的伺服特性与稳定性。从原空间模型出发，建立了两个模态模型，一个是小自由度的模态缩减模型，另一个是中自由度的原模态模型，在原模态模型构成的闭环系统稳定的约束下，对由模态缩减模型构成的伺服系统的性能进行了优化。通过一个简化的定位装置模型结构验证了方法的有效性和实用性。

This study presents approaches for optimum design of structure and servosystem to realize higher performances concerning the positioning and the stability. The proposed approaches use the sensitivity analysis and the nonlinear programming method, in which the integrated optimum design of structure and servosystem is taken into consideration. The performance specifications of the control system are generally expressed as the cahracteristics on frequency and time domains Therefore, this study considers two types of the servosystem, namely one is composed of dynamic compensator such as phase-lead and phase-lag compensators in order to deal with the desired frequency characteristics, and the other is composed of LQI control system in which the controller is desighed to achieve the desired transient responses. The original spatial model of a structure with large degrees of freedom (DOF) is made by the finite element method (FEM). The perfomances and the stability of the servosystem depend on the structural characteristics such as the gain and the phase properties of frequency response function (FRF) between the control input and the output signals. Higher performances of the servo properties and stability of the closed-loop system against the high order natural modes are achieved by the integrated optimization presented in this study. Two modal models are made from the original spatial model, namely one is the reduced modal odel of small DOF and the other is the original modal model of medium DOF.The properties of the servosystem composed of the reduced modal model are optimized under the constranit that the closed-loop system composed of the original modal model must be stable. Effectiveness and practicability of the approaches are verified with a simplified model structure of a positioning device.