Control and Design of Fast Tool Servos for Precision Machining

这笔拨款为开发用于加工应用的高带宽快速执行器和控制提供资金。快速刀具伺服系统将用于加工软件编程的确定性曲面，并补偿加工过程中出现的动态误差。该研究将首先开发一种创新的快速执行器，该执行器将双级固态执行器与流体动力传动相结合，在紧凑的封装中实现高带宽执行。将多变量线性鲁棒性能控制设计方法，将重复控制、预演前馈控制和切削力的影响整合到统一的反馈控制公式中，用于执行器精确生成动态轨迹。为了实现尽可能快的致动器响应，从而可以加工出精细的特征，还将研究脉宽调制的开关控制。将进行加工实验，以测试驱动器和控制能力。特别是，快速工具伺服系统将用于生成非圆形发动机气缸内径形状，以补偿圆柱形误差和表面纹理，从而改善气缸与活塞的配合和摩擦学条件，从而减少排放，提高燃油经济性，并简化制造工艺。如果成功，本研究的结果将导致在速度、精度和一致性等不规则形状零件的加工，如发动机活塞轮廓、活塞销孔和气缸孔的改进。所提出的工作也可能应用于零件的确定性摩擦学表面的加工，如滑动轴承、直线导轨和液压阀/气缸。所提出的工作也有助于一般运动控制领域。所提出的驱动器和控制设计方法有助于扩展运动控制性能，并在加工之外找到新的应用。

This grant provides funding for the development of high bandwidth fast actuators and control for machining applications. The fast tool servos will be used to machine software programmed deterministic surfaces and compensate for dynamic errors occurred in the process. The research will first develop an innovative fast actuator, which combines dual-stage solid state actuators with fluid power transmission for high bandwidth actuation in a compact package. Multivariable linear robust performance control design method, which incorporates repetitive control, previewed feedforward control, and the effect of the cutting force in a unified feedback control formulation, will be developed for the actuator to precisely generate dynamic trajectories. To realize the fastest possible actuator response so that a fine feature may be machined, switching control for pulse width modulation will also be investigated. Machining experiment will be conducted to test the actuator and control capabilities. In particular, the fast tool servos will be used to generate non-circular engine cylinder bore shapes for compensating cylindrical errors and surface texture to provide improved cylinder-piston fit and tribology conditions, thereby reducing emission, increasing fuel economy, and simplifying manufacturing processes.If successful, the results of this research will lead to improvements in the speed, accuracy, and consistency of machining such irregularly shaped parts as engine piston profiles, piston pin holes, and cylinder bores. Potentially the proposed work could also be applied to machining deterministic tribology surface in parts like journal bearings, linear guide ways, and hydraulic valves/cylinders. The proposed work also contribute in the general motion control field. The proposed actuator and control design methods may contribute to extend the motion control performance and find new applications besides machining.