In this paper, a study of a tubular linear actuator with a hybrid core is presented. Through a finite-element analysis software and force measurements, it is shown that, by using a hybrid core combining a permanent magnet and a ferromagnetic material, a higher force density can be achieved in relation of that achieved by using a ferromagnetic core alone. Also, by keeping the ferromagnetic part, the sensorless detection of the core position is possible. A simple position control strategy is proposed, using the inductance variation to indirectly detect the position of the core, in which the duty cycle of the PWM voltage is changed to compensate variations of position or load force. In order to experimentally test the linear motor with hybrid core and the proposed control strategy, a prototype and a control circuit were built. The experimental results clearly demonstrate the advantages and applicability of the hybrid core in linear actuators.

在本文中，提出了一种具有混合芯的管状线性致动器的研究。通过有限元分析软件和力测量结果表明，通过使用结合了永磁体和铁磁材料的混合磁芯，相对于单独使用铁磁磁芯，可以获得更高的力密度。而且，通过保持铁磁部分，可以无传感器地检测芯位置。提出了一种简单的位置控制策略，利用电感变化量间接检测铁芯的位置，其中改变PWM电压的占空比以补偿位置或负载力的变化。为了对混合核心的直线电机进行实验测试，并提出控制策略，建立了原型和控制电路。