Reluctance actuators boast a high motor constant in small air-gap applications when compared to Lorentz actuators. Inherent non-linearities in the F-I relation limit force predictability. Replacing conventional current control with flux control can greatly improve force predictability. Traditionally, hall sensors or hysteresis modelling are employed for accurate flux estimation. This thesis proposes a calibration strategy and control architecture for hybrid flux estimation. The novel control architecture is implemented on a test set-up at MI-Partners. The flux estimator consists of a high pass filtered sense coil and a low pass filtered current probe for integration drift correction. Through comparison of force estimation errors due to magnetic hysteresis, (analog) integration drift and integration errors the optimal crossover frequency was calculated to be 13 mHz. The hybrid control architecture is capable of force prediction accuracy on par with hall control. Simulated positioning accuracy even shows an improvement of 13%, simulations show an improvement in maximum error from 423  micrometer to 369 micrometer. A positioning accuracy improvement of up to 332% over a similar current controlled system has been demonstrated.

In the semiconductor industry, the demand for a continuously higher throughput puts tough requirements on the force capacity and accuracy of actuators. Reluctance actuators, as a promising alternative to the present state-of-the-art Lorentz actuators, are capable of achieving much higher force densities. On the other hand, reluctance actuators suffer from strong intrinsic nonlinearity, such as the quadratic and position-dependent current-force relation, negative stiffness, and magnetic hysteresis, making accurate control challenging. These nonlinear effects can be much suppressed if, instead of controlling the current through the driving coil, the magnetic flux in the actuator core is controlled. As a preparation step for implementing the flux control experimentally on reluctance actuators, this project aims to design and realise the necessary hardware for flux control implementation, including a reluctance actuator prototype and a test setup, and then dynamically calibrate the actuator for flux measurement and control. More specifically, a hybrid reluctance actuator prototype that is suitable for flux control, as well as a test setup for measuring the position and dynamic force output of the actuator, are designed and realised. Using this setup, relations between key variables of the actuator are measured to enable nonlinear compensation in the current and flux control, and a hybrid flux measuring scheme using a Hall sensor and a sense coil is proposed and experimentally implemented. Although noise in the flux measurement is effectively minimised, the result shows a mismatch in the frequency domain between the outputs of the Hall sensor and the sense coil, where further investigation is needed to improve the feasibility of this approach. Furthermore, a hybrid force measuring scheme is proposed and implemented where errors of the load cell due to high-frequency dynamics of the setup can be compensated using acceleration measurements, leading to a wider frequency range for the force measurement. With the realised hardware and the obtained measurements from this project, the next step in future works would be to experimentally implement the flux control on a reluctance actuator and compare its performance with the standard current control.