基于开环快刀伺服的微结构表面高速车削创成

Open-loop fast tool servo-based high-speed turning of micro-structured surfaces

提出了一种开环快刀伺服(Fast tool servo,FTS)系统实现方法,对微结构表面进行高速切削以提高微结构制造效率.针对宽频FTS系统设计,以压电叠堆和柔性铰链为驱动器和导向机构,借助解析模型优化设计了FTS装置参数并进行了有限元验证,实验测试结果表明所设计的FTS获得了预期性能.针对宽频域轨迹跟踪,采用线性动力学模型级联静态Prandtl-Ishlinskii迟滞模型,构建并联合辨识获得了FTS输入与输出间的映射模型,并通过动态迟滞补偿实现了kHz级宽频域内一致性的建模精度和轨迹跟踪精度.最终,借助精密数控车床和FTS样机搭建了切削系统,以典型微结构表面切削创成验证了所提出开环FTS高速切削的可行性.

We developed an open-loop fast tool servo(FTS)system to achieve high-speed turning of microstructured surfaces and improve manufacturing efficiency.In terms of mechanical design,the FTS was built with a stacked piezoelectric actuator and a flexure mechanism,and the structural parameters were determined using analytical kinetostatic and dynamics models,which were then verified using finite element analysis.The experimental testing of the prototype revealed that the designed FTS satisfied the design target to a great extent.In the case of wide-bandwidth trajectory tracking,a hybrid model that can accurately capture the dynamic hysteresis of an actuator over a wide frequency band was created by cascading the linear dynamics model and the nonlinear Prandtl–Ishlinskii,and accordingly,the hybrid model was used to develop a compensation model for the actuator to precisely track the desired trajectory in the open-loop mode.The modeling and trajectory tracking results revealed consistent accuracy over a kilohertz band.Finally,a harmonic microgrid surface was generated by installing the FTS on a precision CNC(Computer numerical control)lathe,demonstrating the feasibility of the constructed open-loop FTS for high-speed turning.