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The composite electromagnetic linear actuator features a co-axial integrated design that merges the moving coil and moving iron actuator types. This design leads to significant interactions among electrical, magnetic, and thermal fields during operation, which in turn affect energy consumption and temperature increases. To further improve the material utilization rate of the actuator and optimize its comprehensive performance, such as force density and temperature rise, a multi-physical field collaborative optimization method was proposed. First, the energy consumption and temperature rise mechanisms of the actuator were analyzed. The bidirectional coupling relationships of multi-physical fields during its operation are studied. Simulations and experiments were conducted to establish the rules governing the spatiotemporal evolution of energy consumption and temperature fluctuations under standard operational conditions. Based on this, a system-level collaborative optimization model for the actuator was established. Sensitivity analysis helped segregate the design variables into system-level and independent categories. Subsequently, using a multi-objective genetic algorithm, the optimal parameter settings were determined. The optimization results revealed that the force constant of the main driving components increased by 5.4%, and the average temperature of the coil decreased by 6.3%; additionally, the starting force of auxiliary components increased by 2.3%, and the temperature of the yoke decreased by 0.8%. [ABSTRACT FROM AUTHOR]

As an important actuator component, the electromagnetic linear actuator has a significant impact on the performance of fully flexible variable valve trains. Aiming at the shortcomings of the conventional moving coil electromagnetic linear actuator (MCELA) with low force density and insufficient end-passive self-holding ability, a novel compound electromagnetic linear actuator (CELA) integrating the advantages of MCELA and the moving iron electromagnetic linear actuator (MIELA) was proposed in this work. The CELA has two operating modes, including single drive mode and cooperative drive mode, and its loss variation is different from that of the single MCELA or MIELA. Firstly, the current and displacement curves under different operating modes were obtained through experiments, which were then used as the excitation source to quantitatively analyze the copper and iron losses under different working conditions by means of 3D finite element simulation. The loss distribution and ratio of CELA under typical operating conditions were discussed in detail. The effects of stroke and valve opening duration on CELA losses were analyzed. The results show that there are significant differences in the loss variation rules between the two operating modes, the losses increase as the working stroke increases in single drive mode. In the cooperative drive mode, the losses are much greater than in the single drive mode, with the losses decreasing in the initial stage and then increasing as the stroke increases. None of the valve opening durations had a significant effect on losses. This study provides a reference for loss studies of other novel electromagnetic linear actuators. [ABSTRACT FROM AUTHOR]

Aiming at the low force density and the lack for lack of self-holding ability at the end of conventional moving-coil electromagnetic linear actuators, a novel compound electromagnetic linear actuator was proposed. According to the structural characteristics, the mathematical model was established; also the cooperative drive mode with high driving capability and the single drive mode with low energy consumption were analyzed. Combining the inverse system and the feed-forward + PI feedback algorithm, the multi-mode coordinated controller of the compound electromagnetic linear actuator was designed. A simulation model was established by MATLAB/Simulink, and a prototype test platform was built. The effectiveness of the coordinated control method was verified through simulation and experiments. The results show that the actuator has good dynamic characteristics under different driving modes, and the displacement control errors are less than ± 0.02 mm. The self-holding force of actuator is as 229.3 N. In the cooperative driving mode, the driving force may reach 574.9 N, and the turn-on transition time is as 4.8 ms; the turn-on transition time under the single drive is as 6.9 ms. [ABSTRACT FROM AUTHOR]

The new compound electromagnetic linear actuator (CELA) features high energy efficiency, high power ratio, fast response and high precision. However, it is compact in structure due to volume constraints. Also, there are significant internal electrical, magnetic and thermal coupling effects and the temperature rise problem is prominent. In this paper, the electric-magnetic-thermal coupling mechanism of multiple physical fields inside the CELA was analyzed first. Considering the influence of different driving modes on energy consumption, the theoretical model of energy consumption was built based on iron loss separation. The heat transfer mechanism and process of the mechanism were studied with energy consumption as heat source. Considering the influence of thermal characteristics on the material properties, an accurate numerical model with electric-magnetic-thermal multi-physical field bidirectional coupling was established. The energy consumption distribution and the transient change characteristics of the temperature distribution with time and space were studied quantitatively under different driving modes and different operating conditions of the CELA. A test platform for energy consumption and temperature rise was established to verify the accuracy of theoretical analysis and simulation. The results showed the test and simulation results were in good agreement under typical operating conditions, with the error less than 2%. [Display omitted] • Compound actuator based on the coaxial integration of two different actuators. • Bidirectional coupling model of electric-magnetic-thermal was established. • Heat transfer mechanism and process of actuator were studied. [ABSTRACT FROM AUTHOR]

The iron loss of inner yoke accounts for the majority of iron loss of an electromagnetic linear actuator (ELA). Therefore, the reduction of iron loss of inner yoke is of great importance to the reduction of iron loss of the whole ELA. This study investigates the formation mechanism and distribution law of ELA iron loss and proposes a reduction scheme by arranging groove structures in the inner yoke. The direction of groove arranged in inner yoke was determined based on the formation mechanism of inner yoke iron loss. Through simulation and calculation based on finite‐element model of electromagnetic field, the authors investigated the effects of the number of grooves as well as groove width on the iron loss and performance of ELA. The optimal grooving scheme of ELA was determined by comprehensive analysis and analytic hierarchy process. Finally, block and static force tests were carried out based on ELA prototype. It was found that the simulation results were consistent with test results, indicating the accuracy of the simulation model. [ABSTRACT FROM AUTHOR]

Electromagnetic linear actuators are widely used as drives in gas regulating valve, which is the key factor to determine the performance of the gas valve. In order to improve the performance of Electromagnetic direct-drive gas valve (EMDGV), a compound controller for non-repetitive point-to-point motions was proposed in this paper, combining with the advantages of Active disturbance rejection control (ADRC), Time-optimal control (TOC) and Sliding mode control (SMC). Simulation and experimental results show that the proposed method has the characteristics of fast response and high precision, and can achieve soft landing control. The response time is less than 8 ms, the control accuracy is 0.02 mm, and the seating velocity is within 0.04 m/s. The proposed method also has strong robustness to actuator parameter variation and good anti-disturbance ability. [ABSTRACT FROM AUTHOR]

Electromagnetic linear actuators, as key executive components, have a vital impact on the performance of fully flexible variable valve trains. Considering that the conventional moving coil electromagnetic linear actuator (MCELA) has the disadvantages of low force density and a lack of end-passive self-holding ability, a novel composited electromagnetic linear actuator (CELA) is proposed by combining the performance advantages of MCELA and moving iron electromagnetic linear actuator (MIELA) in this work. Firstly, the structure and magnetic circuit design scheme of the proposed actuator are introduced and the finite element simulation model is established. The magnetic field distribution and force characteristics of the actuators are assessed by finite element simulation. Secondly, the construction of the prototype of the actuator is outlined, based on which the feasibility of the design scheme and the steady-state performance of the actuator are verified. Finally, the coordinated control strategy is proposed to realize the multi motion coordination control of the actuator. The research results show that the maximum starting force of the CELA with the end-passive self-holding ability is 574.92 N while the holding force can approach 229.25 N. Moreover, the CELA is proven to have excellent dynamic characteristics and control precision under different motion modes and to have an improved adaptability to the complex working conditions of internal combustion engines. [ABSTRACT FROM AUTHOR]