人工心脏泵磁悬浮转子非线性特性及控制方法研究

Research on Nonlinear Characteristics and Control Method for Artificial Heart Pump Magnetic Suspension Rotor

引入滑动模态变结构控制,对转子转速大于6000r/min时转子产生的颤振及转子在强干扰下产生的新的平衡位置等非线性效应进行控制。以轴向为例取切换函数,滑动模态按指数律趋向原点,推导出了等效控制方程。用电锤给轴向磁悬浮转子施加冲击干扰,观察变结构控制的结果,发现系统在短暂调整后即恢复平衡位置,渐近稳定,说明采用变结构控制的适应性较好。利用变结构控制对内部参数变动和外部扰动作用不变这一显著特点,可有利于控制血液应力及粘弹性等非线性因素造成的转子扰动,从而使得系统数学模型的不准确性、实际系统的不确定性及镇定的复杂性得以解决。

The aim of this study was to enhance the robustness of the artificial heart pump magnetically suspended rotor by slide model variable structural control （VSC）. The VSC was used to control quiver as rotor rotated faster than 6000r/min as well as positional changes as the rotor run into strong exterior disturbances. Taking the axial bearing as an example of switch function, the slide mode obeys the index rule incline to origin. From this, an equivalent control equation can be concluded. Using an electric hammer, an impact disturbance was created on the axial magnetic bearing, and the effect of VSC was evaluated. Following a small adjustment, the system returned to the position of equilibrium. The system is asymptotically stable. VSC improves stability and robustness. The use of VCS to minimize interior vibration and exterior disturbance is necessary to control blood stress and viscoelasticity. The VSC mathematical model is accurate, and the uncertainty and adjustment complexity for a truth system are solved.