多重时变因素耦合作用下复杂曲面的混合补偿恒力气囊抛光方法研究

Under the traction of large scientific devices such as Shenguang project, the high-precision and complex curved optical elements are in huge demand. How to manufacture such elements in batches has become an important issue. Polishing is an important stage in manufacturing process flow, but its removal is unstable and time-varying, which affects process certainty and polishing efficiency. Based on this, this project takes the high efficient bonnet polishing of complex surface as the object, and the removal instability inducing by the multiple time-varying factors as the starting point. It aims to improve removal stability based on force monitoring and compensation. Dynamic contact model of tool and workpiece is built to explore the contact state, and the mechanism of time-varying characteristics of the process is clarified. The relationship between multiple time-varying factors (such as tool performance and workpiece curvature) and polishing force is revealed, which is used to derive the multiple time-varying tool influence function(TIF) model of the bonnet polishing. The hybrid compensation strategy mixing with off-line compensation and on-line adaptive compensation is proposed to suppress the time-varying characteristics of polishing force and TIF, so as to break through constant force bonnet polishing method with hybrid compensation technology for complex curved surfaces. The findings of this project can improve the polishing stability and manufacturing efficiency of complex curved surfaces, and provide a technical reference for improving the batch manufacturing capability of complex curved surfaces.

在神光工程等国家大科学装置的牵引下，高精度复杂曲面光学元件需求量巨大，如何批量制造该类元件是一个重大难题。抛光是该类元件加工的重要环节，但受到抛光过程时变因素影响，元件加工效率和批量制造水平受到极大限制。本项目以复杂曲面的高效气囊抛光为对象，以多重时变因素耦合作用导致去除稳定性不足为切入点，围绕基于力监控与补偿来提升去除稳定性的目标开展研究。从建立工具与曲面的动态接触模型出发，探索二者接触状态变化规律，阐明多重时变特征产生机理；建立多重时变因素（如工具性能、工件曲率）与抛光力的映射关系，揭示抛光力的时变规律，推导气囊抛光多重时变去除特性预测模型；提出离线与在线自适应相耦合的复杂曲面混合补偿抛光策略，抑制多重时变因素耦合作用下抛光力、去除特性的时变性，以此来突破复杂曲面的混合补偿恒力气囊抛光方法。项目成果可提高复杂曲面元件抛光稳定性和加工效率，为提升复杂曲面元件批量化制造水平提供技术参考。

针对复杂曲面气囊高效抛光过程中去除时变影响加工精度与效率的问题，首先通过工具与曲面的动态接触分析，掌握多重时变因素（工具性能、工件曲率）与抛光力的映射关系，并建立了气囊抛光多重时变去除特性预测模型；然后，建立了考虑去除时变的动态去除模型，实现了加工误差的动态预测；进一步，建立了基于加工误差的机器人运动误差离线补偿模型，通过运动误差原位补偿大幅提升运动精度以及去除稳定性；最后，搭建了基于力控的机器人气囊抛光系统，开发了具有恒力控制能力的复杂曲面机器人气囊进动运动控制算法和工艺软件，实现了复杂曲面机器人气囊在线自适应恒力抛光。通过本项目研究，构建了基于离线与在线补偿结合的复杂曲面机器人气囊恒力抛光软硬件能力，初步形成了复杂曲面机器人气囊高效动态抛光关键方法，为复杂曲面光学元件加工提供了一种兼具“高效率、高精度、低成本”优势的技术选择。