大变形非线性柔性铰链多轴平台设计与高带宽协同控制

High-precision micro-hole array laser drilling equipment requires the motion stage which can achieve high-speed precision interpolation of millimeter-scale stroke. The existing galvanometer-based laser drilling machine is less accurate and easy to produce the tapered holes. Due to the existence of friction and large inertia, it is difficult for the traditional mechanical motion stage to meet the high-efficiency requirements of micro-hole array laser drilling. This project studies how to use the large deformation flexible hinge mechanism and the direct drive approach to realize the high-speed interpolation and high-speed positioning movement with the millimeter stroke, which can greatly improve the production efficiency of the micro-hole array laser drilling equipment. The main research contents are as follows: 1) Study the nonlinear stiffness and inertia formulas of large deformation flexible hinge based on plate and shell theory, overcoming the disadvantages of the existing beam model cannot be adapted to the flexible hinge with large width to thickness ratio; 2) study the bearing ability of single side bearing flexible hinge to realize dynamic balance design of macro-micro system and achieve multi-axis dynamic characteristic matching; 3) study nonlinear stiffness/frequency estimation and compensation method to realize high-transmission control of low-frequency and nonlinear systems; 4) study the motion planning method of macro-micro composite system with nonlinear low-frequency modal to realize fast and precise positioning. The project's research provides theoretical support for the design and high-bandwidth coordinated control of multi-axis motion stage based on large-stroke nonlinear flexible hinges.

高精密微孔阵列激光加工等装备需要运动平台实现毫米级行程的高速精密插补。现有基于振镜的激光打孔设备精度低且会产生锥孔，传统机械平台由于存在摩擦，且惯性较大，导致加工效率较低，难于满足微孔阵列高效加工需求。本项目研究如何利用大变形柔性铰链机构与直驱方式来实现毫米行程的高速插补和高速定位运动，从而大幅提高微孔阵列激光加工设备的生产效率。主要研究内容有：1）研究基于板壳理论的大变形柔性铰链非线性刚度与惯性近似解析模型，克服现有梁模型不能适应大宽厚比柔性铰链的弊端；2）研究单边承载柔性铰链的承载能力，实现宏微系统的动态平衡设计，并实现多轴动态特性匹配；3）研究刚度频率非线性估计与补偿方法，实现低频、非线性系统的跨带宽高响应控制；4）研究含非线性低频模态的宏微复合系统的运动规划方法，实现快速精密定位。项目的研究为基于大行程非线性柔性铰链的多轴平台的设计和高带宽协同控制提供理论方法支撑。

高精密微孔阵列激光加工等装备需要运动平台实现毫米级行程的高速精密插补。现有基于振镜的激光打孔设备精度低且会产生锥孔，传统机械平台由于存在摩擦，且惯性较大，导致加工效率较低，难于满足微孔阵列高效加工需求。本项目利用大变形薄片式柔性铰链设计了满足激光微孔阵列加工所需的高频高精大行程需求的XY轴柔性运动平台，针对柔性机构易受谐振扰动、高频噪声等影响的特点开发了基于自抗扰控制技术的高带宽控制系统与适应柔性平台动力学特性的高速高精运动规划方法。其中，在大变形柔性铰链设计方面，提出了适用于大变形非线性工况的柔性铰链变形与刚度计算模型，设计了一种具有增强约束度方向刚度的柔性机构以满足柔性平台的承载要求。在低频非线性系统高带宽控制方面，柔性平台受到的非线性扰动可以通过柔性铰链的连续柔性变形被转换为可以被弹性变形扰动，并利用自抗扰控制技术的扩张观测器来快速估计上述扰动，最终利用自抗扰控制系统的低控制带宽高观测带宽的特点快速补偿扰动实现多轴柔性平台的高带宽控制。在考虑非线性低频模态影响的高速运动规划方面，建立了考虑柔性机构频率鲁棒性约束的运动规划优化方法，定义了一种高阶非对称S型运动规划曲线。在典型低频情况下，5-6阶非对称S型曲线较之现有的对称S型曲线可以缩短定位时达40%以上。基于本项目研究内容设计的多轴柔性平台可以实现50mm/s、50Hz的高频往返运动。本项目的研究成果可以应用于Mini LED芯片巨量转移设备的开发，目前已经作为关键技术获得有国家重点研发计划项目资助。