Investigation Of Controlling System For Magnetostrictive Actuator

The controlling system of a magnetostrictive actuator was investigated, based on automatic control theory and combined with the static and dynamic properties of magnetostrictive materials. The printed circuit board was designed, and the system was debugged. The controlling system is made up of two parts, the hardware and the software. The hardware composes of several parts such as human-machine interface, analog-to-digital converter, memory interface, digital control power. The software functions as data collection, disposal and output. The system has characteristics of speediness, high precision and automatism.The static and dynamic properties, such as magnetostriction, hysteresis loop, dynamic strain coefficient and magnetomechanical coupling coefficient were measured with the magnetic measurement system of multiple parameters. It is found that the measurement result is reliable and repeated and that the parameters can be used to design an actuator.The model of the closed loop controlling system for the actuator was founded in reference to automatic control theory. Based on the input-output model and the transfer function, the simulations, such as step and frequency response and the design of appropriate digital controller were carried out.The hardware circuit of the system was designed on the base of circuit theory. The core of the controlling system-CPU is DSP (TMS320C31). The circuit design mainly includes interface designs, such as address coding circuit, memory, human-machine, AD converter, the power, etc. The PCB was protracted and tested. The testing result indicates that the circuit design is logical, and it can reach an expected target.The testing of time domain property for the actuator, the installation and debugging for the controlling system were completed. The time domain property test contains static property test and step response test. Depended on the result of the test, the transfer function of the system was deduced. The debugging comprises open loop and closed loop debugging. The result shows that the controlling system works steady, quickly and precisely. The actuator can achieve the minimal step distance of less than 0.2 urn.