Dynamic modelling of a normal-force actuator

The paper has described the modelling of the dynamic behaviour of a simple normal-force actuator. It has shown that a relatively simple model can give very satisfactory prediction of current and position. Initial rapid fluxing of the core followed by freewheeling has been presented as a simple means of improving the conventional excitation method, giving much reduced noise and vibration, and improved efficiency. Furthermore, the monitoring of the current during freewheeling has been proposed as a means of exploiting the capabilities of electronics to achieve more improvement