Sensorless control of a novel stepped hydraulic flow control valve

Abstract 

This paper aims to create a sensor-less feedback position detection for a flow control orifice actuated by a stepper motor. Nowadays, many applications such as hydraulic and pneumatic systems use a stepper motor as an actuator, instead of traditional mechanical or solenoid. In nonlinear environment such as hydraulic systems, a stepper motor may suffer from step losing and leads to poor controllability of the system. Mechanical sensors are usually used as a feedback of the position and speed, but at the same time the harsh environment of hydraulic applications prevents implementing this kind of sensing. On the other hand, a sensor-less technique based on Kalman filter was used to control a stepper motor in different applications. This research represents a primarily investigation of the performance of Kalman filter in these for the valve based on modelling and simulation.