Integrated Optimum Design of Structure and Servosystem in Information Processing Equipments

提出了结构和伺服系统的优化设计方法，以实现更高的定位性能和稳定性。该方法采用灵敏度分析和非线性规划方法，考虑了结构和伺服系统的整体优化设计。控制系统的性能指标一般表示为频域和时域上的特性，因此，本研究考虑两种类型的伺服系统，一种是由相超前和相滞后补偿器等动态补偿器组成，以处理期望的频率特性，另一种是由LQI控制系统组成，其中控制器被设计为实现期望的瞬态响应。采用有限元法建立了大自由度结构的原始空间模型。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增益和频响函数（FRF）相位特性等结构特性。本文提出的综合优化方法提高了伺服特性的性能，提高了闭环系统对高阶自然模态的稳定性。在原始空间模型的基础上建立了两个模态模型，即小自由度的简化模态模型和中等自由度的原始模态模型。在由原模态模型组成的闭环系统必须稳定的约束下，对由简化模态模型组成的伺服系统进行了性能优化。通过一个定位装置的简化模型结构验证了该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.