【目的】针对可控励磁直线同步电动机(CELSM)在复杂突变负载扰动作用下难以同时兼顾高精度轨迹跟踪、强抗扰能力与控制输入平滑性的问题,提出一种改进型变增益超螺旋滑模控制(IVG-STSMC)策略,以提升系统动态响应品质并抑制滑模控制中的高频抖振。【方法】首先建立CELSM在d-q坐标系下的数学模型。在此基础上,采用连续Softsign函数替代传统符号函数,并引入基于状态误差的变增益自适应调节机制,构建变增益超螺旋滑模控制器(VG-STSMC),以缓解固定增益与符号函数不连续切换引起的抖振与收敛速度之间的矛盾。进一步地,在VG-STSMC基础上引入无需加速度测量的非线性干扰观测器(NDOB),对系统集总扰动进行在线估计,并通过前馈补偿构建IVG-STSMC复合控制框架。【结果】仿真结果表明,在幅值为1 mm、频率为0.5 Hz的正弦参考轨迹跟踪条件下,IVG-STSMC在跟踪精度、速度平滑性及电流抖振抑制方面整体优于比例积分控制和传统SMC。在t=1.0 s施加50 N阶跃负载、t=2.5 s切除负载的复合工况下,相较VG-STSMC,IVG-STSMC的最大跟踪误差降幅51.8%;在扰动切入瞬间,误差峰值降幅为65.5%。同时,IVG-STSMC进一步改善了扰动切换时刻速度与q轴电流响应的平滑性。【结论】所提IVG-STSMC策略能够有效协调CELSM进给系统在复杂负载扰动条件下的轨迹跟踪精度、抗扰性能与控制输入平滑性,验证了变增益高阶滑模调节与扰动前馈补偿协同机制的有效性。

[Objective] To address the challenge that controllable excitation linear synchronous motor (CELSM) faces in simultaneously achieving high-precision trajectory tracking, strong disturbance rejection, and smooth control input under complex sudden load disturbances, an improved variable-gain super-twisting sliding mode control (IVG-STSMC) strategy is proposed. This strategy aims to enhance the system’s dynamic response quality and suppress the high-frequency chattering inherent in conventional sliding mode control. [Methods] Firstly, a mathematical model of the CELSM in the d-q coordinate system was established. On this basis, a continuous Softsign function was employed to replace the traditional sign function, and a variable-gain adaptive adjustment mechanism based on state errors was introduced to construct the VG-STSMC controller. This step was taken to alleviate the conflict between chattering and convergence speed caused by the fixed gain and discontinuous switching of the sign function. Furthermore, a nonlinear disturbance observer (NDOB) without acceleration measurement was incorporated into the VG-STSMC to estimate the lumped disturbance online. Finally, a composite IVG-STSMC control framework was established through feedforward compensation. [Results] Simulation results demonstrated that under the condition of sinusoidal reference trajectory tracking with an amplitude of 1 mm and a frequency of 0.5 Hz, IVG-STSMC outperformed both proportional integral control and conventional SMC overall in terms of tracking accuracy, speed smoothness, and current chattering suppression. Under the compound working condition where a 50 N step load was applied at t=1.0 s and removed at t=2.5 s, a 51.8% reduction in maximum tracking error was achieved by IVG-STSMC compared to VG-STSMC, and a 65.5% reduction in peak error was recorded at the exact moment the disturbance was introduced. Furthermore, the smoothness of the speed and q-axis current responses during disturbance switching was further improved by IVG-STSMC. [Conclusion] The proposed strategy effectively coordinates trajectory tracking accuracy, disturbance rejection capability, and control input smoothness of the CELSM feed system under complex load disturbances, verifying the effectiveness of the synergistic mechanism between variable-gain higher-order sliding mode regulation and disturbance feedforward compensation.