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.
Automated mechanical transmission has many advantages such as simple structure, high mechanical efficiency, and low cost. But the poor gearshift performance restricts the massive application of the automated mechanical transmission, and it can be improved through innovation of structure and control. To reduce the requirement of shift force and improve the shift performance, a new direct-drive electromagnetic gearshift system which consists of servo synchronizer and 2-degree-of-freedom electromagnetic actuator is adopted. The specific structure and working principle of the gearshift system including servo synchronizer are described, and the equation of force-amplifying ratio is deduced. Due to the complexity of the gearshift system and uncertainties of the gearshift process, active disturbance rejection control method is designed. The active disturbance rejection controller can eliminate the nonlinearity of the 2-degree-of-freedom actuator. The extended state observer can estimate and compensate the uncertainties, parameter variations, and external disturbances. Simulations are carried out, and the result comparison with proportional–integral–derivative controller indicates the superiority of the active disturbance rejection control method. Test bench and control system are developed to verify the performance of the newly designed system and control method. The experimental results show that, when the gearshift system is equipped with servo synchronizer, the driving force and the maximum volatility of driving force can be reduced by 35% and 5%, respectively, and the impact generated by active disturbance rejection control method is reduced by 36% compared with proportional–integral–derivative method. The new gearshift system achieves a better gearshift performance. Combined with the newly designed control strategy, the direct-drive electromagnetic gearshift system provides a new solution for automated mechanical transmission applications.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.