This paper presents an observer-based fast nonlinear model predictive control (NMPC) scheme for translation control of magnetically levitated (maglev) positioning system subject to input saturation. The motivation lies in the improvement of transient characteristics and control performance for positioning systems. The nonlinear dynamical translation model of the maglev positioning system is derived that does not affect the rotation dynamics with special current conditions. The disturbance estimation, obtained by nonlinear disturbance observer, is introduced in the state receding prediction to compensate the errors caused by disturbances and uncertainties. To reduce the computational burden, the stability of the proposed NMPC is established without using any stability-related terminal costs or constraints, and only the short prediction horizon is required for real-time feasibility. The online optimization algorithm underlying the NMPC scheme takes the process constraints into account, and solves the optimal control problem using a parallel structure at each iteration. Comparative experiments are carried out on the positioner to validate the proposed controller has the outperformance in transient/steady-state trajectory tracking, frequency characteristics and robustness against disturbances. The proposed scheme also provides a guidance for the application of NMPC in industrial mechatronic system with fast dynamics.

本文提出了一种基于观测器的快速非线性模型预测控制 (NMPC) 方案，用于受输入饱和影响的磁悬浮 (maglev) 定位系统的平移控制。其动机在于改进定位系统的瞬态特性和控制性能。推导了磁悬浮定位系统的非线性动力平移模型，该模型不影响特殊电流条件下的旋转动力学。在状态后退预测中引入由非线性扰动观测器获得的扰动估计，以补偿由扰动和不确定性引起的误差。为了减少计算负担，建议的 NMPC 的稳定性是在不使用任何与稳定性相关的终端成本或约束的情况下建立的，并且实时可行性只需要较短的预测范围。NMPC 方案背后的在线优化算法考虑了过程约束，并在每次迭代时使用并行结构解决最优控制问题。在定位器上进行了对比实验，以验证所提出的控制器在瞬态/稳态轨迹跟踪、频率特性和抗干扰鲁棒性方面具有优异的性能。所提出的方案还为NMPC在具有快速动态的工业机电一体化系统中的应用提供了指导。在定位器上进行了对比实验，以验证所提出的控制器在瞬态/稳态轨迹跟踪、频率特性和抗干扰鲁棒性方面具有优异的性能。所提出的方案还为NMPC在具有快速动态的工业机电一体化系统中的应用提供了指导。在定位器上进行了对比实验，以验证所提出的控制器在瞬态/稳态轨迹跟踪、频率特性和抗干扰鲁棒性方面具有优异的性能。所提出的方案还为NMPC在具有快速动态的工业机电一体化系统中的应用提供了指导。