This paper introduces a new type of active electrostatic suspension system without using position sensors. The concept is to design a feedback controller without using position signals of the object instead using the voltage signals. In the working process of the electrostatic suspension system, the capacitance formed between the electrode and the suspended object is treated as a capacitor of two parallel plates, and if the gap length between them is changed the capacitance is then changed. This causes to change the voltage across the capacitance formed between the electrode and suspended object. This voltage is measured, and it then is used to estimate all variables of the system that are the displacement, velocity of the suspended object, and voltage across the capacitance formed. These estimated values are employed in the feedback schema instead of actual states values. The design of the controller follows the classical observer state-space approach. First, a state feedback controller is constructed with the assumption that all the state variables of the suspension system that are displacement, velocity of the suspended object, and voltage across the capacitance formed by the electrodes and the suspended object, are available for feedback. Second, a full observer is designed for estimating all the states from the measured voltage across the capacitance. Finally, the estimated signals produced by the full observer are used in the feedback controller instead of the actual states, and the self-sensing electrostatic suspension without using position sensors is achieved. The experimental and simulation results show that the suspended object successfully levitated at reference gap without using position sensors.

本文介绍了一种不使用位置传感器的新型主动静电悬架系统。其概念是设计一种反馈控制器，而不使用对象的位置信号，而是使用电压信号。在静电悬浮系统的工作过程中，在电极和悬浮物之间形成的电容被视为两个平行板的电容器，如果改变了它们之间的间隙长度，则电容会改变。这导致改变在电极和悬浮物之间形成的电容两端的电压。测量该电压，然后将其用于估算系统的所有变量，这些变量是位移，悬浮物体的速度以及所形成的电容两端的电压。在反馈模式中采用这些估计值，而不是实际状态值。控制器的设计遵循经典的观察者状态空间方法。首先，在假设悬浮系统的所有状态变量（包括位移，悬浮物体的速度以及由电极和悬浮物体形成的电容两端的电压）可用于反馈的情况下，构造状态反馈控制器。其次，设计了一个完整的观察器，用于根据电容两端的测量电压估算所有状态。最后，由完整观察者产生的估计信号用于反馈控制器，而不是实际状态，从而实现了无需使用位置传感器的自感式静电悬架。