基于全局任务坐标系的高维运动平台受限优化轮廓控制

High-performance contour machining based on high-dimensional motion stages is an important part of modern manufacturing technology. It has great strategic significance and potential applications in various industry to realize high-speed and high-precision contouring motion control. Currently, the study on multi-axis coupling dynamics modeling for these systems are not complete. Existing contouring error calculation model and task coordinate frame theory cannot completely solve the tracking problem for high-speed and large-curvature contouring tasks in systems with more than two DOFs. The online trajectory planning methods are also sensitive to modeling errors and external disturbances. This project is to develop high acceleration and high precision multi-axis motion stages and test systems. Multi-axis coupling dynamics modeling method and parametric model representation based on the rigid-flexible coupling characteristics will be studied. The contouring error calculation model which is suitable for the real-time control realization will be explored and corresponding global task coordinate frame definition will be proposed for complex high-dimensional trajectory. Taking the modeling errors and disturbances into consideration, the constraints of time-varying dynamics will be studied as well as the kinematics constraints, under both of which an online trajectory planning method will be proposed for contouring tracking tasks. With the proposed systematic theory and design method of coordinated contouring control, the results of this project will help high-dimensional motion stages realize their potential of high-speed/high-precision contouring tracking with strong disturbance rejection capability.

基于高维运动平台的高性能轮廓加工是现代制造技术的重要组成部分，实现高速高精度协调轮廓运动控制具有重要的战略意义和工业应用前景。现有针对该类系统的多轴耦合动力学建模研究并不完备、轮廓误差计算模型和任务坐标系理论无法彻底解决二维以上系统高速大曲率轮廓跟踪问题、受限约束下在线轨迹规划方法也易受到建模误差与外干扰等因素的影响。本项目将研制能实现高加速和高精度的多轴精密运动平台及试验系统，研究其基于刚柔耦合特性的多变量耦合动力学建模理论及参数化模型表示方法；探索高维复杂轮廓下适用于实时控制的轮廓误差计算模型及全局任务坐标系定义；考虑建模误差以及外干扰影响，研究高维系统轮廓跟踪任务中受运动学和时变动力学约束下的在线轨迹规划方法；通过系统建立受限优化协调轮廓控制设计理论与方法，实现此类高维运动平台具有强抗干扰能力的高动态高精度轮廓跟踪。

在现代化制造业领域，高维运动平台作为一类通用的基础性部件广泛的应用于各种高端精密制造设备中，例如精密加工中的多轴联动数控机床、焊接生产线上的多轴机器人手臂、半导体产业所需用到的精密光刻系统等。此类系统的实际任务往往需要实现空间曲线轮廓或曲面轮廓加工。随着行业对设备的加工精度、动态性能和制造效率等性能指标日益增高的要求，现有的多轴轮廓协调控制策略已无法实现其要求，具体而言主要有以下几个问题：高维运动平台由于某些部件的相对柔性等特征，往往导致各轴动力学之间存在耦合，制约了系统的动态性能；此外，现有轮廓误差模型和轴间协调机制在高速大曲率复杂轮廓任务下性能较差；同时为满足机电系统轮廓运动跟踪任务中的高效率要求，此类系统需要在受限于实际中各种运动学和动力学约束的情况下，以尽量快的运动速度完成作业任务，提高运动速度有助于获得高效率的运动跟踪性能，但也可能会违反此类约束，造成控制器饱和，进而导致运动跟踪精度的急剧恶化甚至控制系统失稳。因此，本课题围绕如何实现高维运动平台的高性能轮廓运动控制这一主题，研究了高维运动平台的刚柔耦合特性及建模方法，建立了适用于高维复杂轮廓曲线的轮廓误差模型和全局任务坐标系，提出了适用于多轴的有效运动协调机制和轮廓控制方法，最后，完成了考虑运动学和动力学约束限制的轨迹规划方法，所提出的集成在线轨迹规划和自适应鲁邦控制的双环控制算法同时保证了系统最短时间的瞬态跟踪性能和高精度的稳态跟踪性能。