Energy-Efficient PM-Flux-Based Sensorless Soft Landing Control for Binary Electromagnetic Actuator

Binary actuators with discrete states are widely used in various fields, including medical endoscopes, combustion engine valves, and manufacturing applications with the advantages of simple system structure, low manufacturing cost, and high repeatability. Electromagnetic actuating mechanism is often adopted for such binary actuators due to its simplicity and accessibility. By utilizing the magnetic flux of permanent magnet (PM) and electromagnet simultaneously, such electromagnetic actuators can achieve higher force density with minimum power consumption. However, nonlinear magnetic reluctance force accelerates the mover toward the discrete state, causing an impulsive collision with the stator and so impairing the reliability of the binary actuator performance. To address such issues, this article proposes a PM-driven-flux-based sensorless control of electromagnetic binary actuators to realize the soft landing of the mover and therefore minimize the undesired contact bounce, surface wear, and associated acoustic noise. Overcoming the trade-off between the soft landing performance, fast actuation time, and potential energy consumption is also considered in the proposed control strategy. The experimental results show significant reduction rates more than 80% on the contact bounce amplitude and mover landing velocity, while also reducing the actuation time and energy consumption more than 30% as compared to the other conventional control methods in prior art.