New results for position estimation in electro-magnetic actuators using a modified discrete time class A/B model reference approach

In this paper, a number of new results are presented that have been achieved with a previously suggested approach for estimating the armature position of electro-magnetic actuators. With the assumption that only current and voltage measurements are available, a discrete time model reference adaptive system (MRAS) is used. It is shown that by identification of the parameters of the electrical subsystem, an accurate estimate for the armature position can be obtained. A combination of two discrete time MRAS methods is proposed in order to take advantage of their complementary properties. It is shown in practical experiments that with this approach robust and fast estimation of the electrical parameters is achieved and the position estimation can thus be solved in real world applications. Moreover, the dependencies of the electrical parameters on the magnetic hysteresis are shown.