Position estimation in electro-magnetic actuators using a modified discrete time class A/B model reference approach

Abstract

In this paper, the use of a discrete time model reference adaptive approach is proposed for estimating the armature position of electro-magnetic actuators. It is assumed that current and voltage measurements are available, only. It is shown that by identification of the parameters of the electrical subsystem, a unique and accurate estimate for the armature position can be obtained. To this end two discrete time MRAS methods are combined in order to take advantage of 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 environments.

A Solution to Ambiguities in Position Estimation for Solenoid Actuators by Exploiting Eddy Current Variations

“…The state-of-the-art works [23,27,28] model eddy current losses inside an actuator by a lumped parameter system. In general, all the above-mentioned techniques, disregarding the estimation approach, exhibit the strong sensitivity of the different parameter model containing a leakage resistor in parallel to the main inductance of the solenoid.…”

“…However, due to a high measurement variance, the work avoids the exploitation of that parameter. Instead, the works [27,28] identify the parallel resistance by means of a model adaptive reference system (MRAS) and validate the usability of this parameter for position estimation in experimental tests. In order to improve the estimation performance, the information is merged with an estimate of the differential inductance by means of binary decision-making.…”

“…In order to improve the estimation performance, the information is merged with an estimate of the differential inductance by means of binary decision-making. Further improvements are obtained by increasing the sample time of current and voltage measurements [27,28]. Nevertheless, such high sampling and computational efforts seem not to be adequate in low-cost applications.…”

State and parameter estimation in solenoid nonlinear equations

“…The position to inductance dependance is refined in the work of Dülk and Kovácsházy, where the external load on the solenoid is also estimated, as well as in their other previous works,() where the same authors developed a method such that a sinusoidal component is superposed onto the base duty ratio of the drive PWM. Other methods() use a model reference adaptive system approach to estimate the change in electrical parameters depending on the armature position.…”

“…Recently, contactless estimation of the armature position in electromagnetic actuators has acquired great interest in the research community. [1][2][3][4][5][6][7][8][9][10][11] In a system control or the detection of defects and anomalies, it is very important to know at any time the air gap width or the armature position of a solenoid. To this aim, different approaches have been proposed in the literature.…”