Adaptive microprocessor control of a linear helical reluctance motor

It has been shown previously that open-loop control, using a dedicated microprocessor, achieves a very satisfactory dynamic and static performance. However, this performance is only valid provided that output inertia and load torque do not vary. This paper extends the work to closed-loop operation in which a nonlinear sampled-data feedback controller is proposed. It is found that the resulting system resolution is inferior to that achieved with open-loop control and leads to the concept of two-mode control with open-loop control operating at input displacement demands below ±1°, to achieve good resolution. Finally an adaptive controller is implemented to cope with wide variation of load mass of about three times the rotor mass. Optimum dynamic resolution is of the order of ±0.25° (¿ ± 3× 10¿3m).