As a kind of energy converter, high quality electromagnetic linear actuator is the focus of the research. A new flow regulation method for metering pump is proposed, a novel bi-stable linear force actuator (BLFA) is investigated corresponding to reduce power consumption and enhance drive capability. A coupling model including a loss model, an electromagnetic model and a mechanical model was constructed. The influence rule of the structural parameters on force characteristic was investigated. Through structural parameter design, force versus position characteristic is high-linearity in working area and the minimum threshold value of drive force (start-up force) reaches 139 N without spring mechanism, which effectively reduces the device’s volume. Besides, power consumption in holding phase is decreased because of holding force. Moreover, an innovative pulse current excitation mode was adopted to reduce power consumption further. Experimental and simulation results validate the static and dynamic performance of BLFA. The circulating power consumption of prototype is 3.1 J, which does not change with the working frequency and has decreased by 34% compared with the traditional excitation mode. Additionally, the advantage of BLFA’s performance was also verified with directly-driven metering pump flow characteristic experiment.

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Direct-Driving Automated Mechanical Transmission (DAMT) gearshift actuator is a kind of electromagnetic linear actuator. In practical application, the actual gearshift force in each steady states is significantly different from the electromagnetic force model. For the optimization of gear shifting actuator with undetermined volume constraint, this paper presents a variable weight coefficient optimization method of electromagnetic linear actuator which equates the output forces under different steady states in the fitness function. These are intended to adjust the relationships among the optimized objects by using the fitness function to improve the overall optimization effect. In order to obtain the fitness value of each combination parameter accurately, finite element analysis (FEA) is adopted in this paper, to improve the efficiency of the algorithm, and a more efficient simulated annealing-particle swarm optimization algorithm (SA-PSO) is used by the proposed optimization method. Finally, experiment is carried out based on prototype of gearshift actuator to verify the optimization results. The results show that the maximum electromagnetic force and terminal electromagnetic force are both increased by more than 20%, and the volatility of gearshift force is reduced 26.4%, which ensures the structure compactness and fast response. The proposed method decreases the volatility by 27.5% compared with the constant weight coefficients and improves the gearshift force in each stage. INDEX TERMS DAMT, gearshift actuator, variable weight coefficient optimization, experiment.

In accordance with the developing trend of “safety, comfort and low-carbon” technology, the market for intelligent X-by-wire chassis is huge. A new requirement of the X-by-wire system, including the response, accuracy, energy consumption and fault-tolerance, is put forward. Based on the analysis of the structure and design flow of the brake-by-wire (BBW) system, this paper analyzes the research status and development trend of the control methods of braking force, coordination control strategies and fault-tolerant control of the BBW system. The application possibilities of direct-driving technology in the BBW system are analyzed. At present, the key points of research focus on considering the influence of the multi-field coupling effect in the design, observing and compensating various nonlinear factors, and having a higher requirement for fault-tolerant control. Finally, an intelligent direct-driving BBW system is proposed as a research direction, which takes high efficiency and energy saving as a foothold and aims at breakthroughs in dynamic response, control accuracy and fault-tolerant abilities.

In this study, to enhance the frequency-flow characteristics of the novel electromagnetic direct-drive pump (EDDP). An adaptive disturbance observer-based improved super-twisting sliding mode control (ISTSMC-ADOB) is proposed to address the problem in which the response quality is deteriorated by factors such as parameter mismatch and disturbance. An adaptive disturbance observer (ADOB) is designed to achieve adaptive compensation, avoid the use of high-gain feedback, and extend the applicability of the conventional disturbance observer (DOB). An improved super-twisting sliding mode control (ISTSMC) based on the fast terminal sliding mode (FTSM) algorithm is designed to ensure faster convergence of the error in finite time. By combining the ADOB with the ISTSMC, the conservative parameter selection of the sliding mode control (SMC) is avoided, and the accuracy and robustness are further strengthened. The stability is analyzed based on Lyapunov. The results show that the proposed method effectively improves the steady-state accuracy, response speed, and robustness in trajectory tracking of the electromagnetic linear actuator (EMLA) for the EDDP. This further enhances the frequency-flow characteristics of the system.