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The limited-angle torque motor (LATM) is an electric actuator capable of rotating within a limited angular range and outputting a stable torque. It features a simple structure and high reliability and can be used in precise position or torque control scenarios. To reduce the torque fluctuation within the constant torque range (CTR), the effects of the stator tooth topology and size, PM magnetization direction and size, and sleeve permeability on the torque-angle characteristic of the LATM within the CTR were analyzed through FEM simulation, and the characteristics of the LATM before and after optimization were compared. Furthermore, a magneto-thermal coupling simulation of the steady-state temperature increase and thermal deformation generated by the LATM was conducted to study the effect of temperature on the LATM. The results show that the optimized LATM can output a more stable torque within the CTR and that the rated torque fluctuation rate relative to the torque at the zero position decreases by 3.2%. In addition, the temperature increase and corresponding thermal deformation of the optimized motor at 20 °C decreased by 0.22% and 0.29%, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a methodology for evaluating different flight control actuation system architectures in the early conceptual design phase. In particular, this paper shows how hydraulic and electric actuators can be modeled even if very little is known about the aircraft design or requirements while still including the most dominant static and dynamic characteristics. Singular Value Decomposition is used to estimate model parameters and actuator characteristics from industrial data. This is a quick way to estimate what is needed with little input. The purpose of the models is to predict the power consumption, cooling needs, weight, and size. This is performed by integrating the actuator models in a dynamic simulation framework that also includes a flight simulator and surrounding systems. The results from subsystem studies support the aircraft design process, where actuator characteristics affect the engine performance and aircraft sizing. The methodology is applied to a generic fighter by comparing hydraulic and electric actuation system architectures. Besides providing a generic approach to the actuator modeling, the parameters that affect both the static and dynamic characteristics of an electromechanical and electrohydrostatic actuator are estimated with reasonably good accuracy with only four design parameters as input. [ABSTRACT FROM AUTHOR]

The transition of heavy machinery systems in agriculture is becoming increasingly urgent due to evolving regulations, market volatility in fossil fuels, and the imperative to achieve decarbonization objectives in the sector. Agricultural machinery has recently experienced an increase in automation, resulting in a higher implementation of electric actuators and systems in agricultural machinery. This, combined with the higher energy efficiency of electric powertrains and the potential of local energy generation on farms, makes full electrification of these systems increasingly attractive. In this article, a new model capable of simulating electric non-road heavy machinery systems with a local grid-connected energy management system and two on-field energy replenishment modes: on-field battery exchange and charging, is presented. The model is built as a discrete event simulation, and planning algorithms are implemented to enable agent cooperation and process optimization. Moreover, the model is configured with real-world weather, geographical, and operational data collected from two participating Swedish farms, and two case studies are conducted, simulating full electric field operation on the farms. The results show that it is possible to perform the fieldwork with a process time consumption that is only 5% higher than a diesel-driven machine system baseline while consuming just 37.5% of the energy. The effects of different battery sizes, grid connection power levels, and energy replenishment modes are explored, and the impact on the total process effectiveness and electrical system load is shown. It is concluded that although a battery-based system can reach similar process effectiveness to its diesel counterpart, the batteries in the system must have an alternative use during periods of low farming activity for the system to be economically competitive. • Novel study, battery-electric agricultural systems with on-field energy replenishment. • Battery-electric agricultural systems can achieve similar effectiveness to diesel. • On-field battery exchange achieves higher effectiveness than on-field charging. • The potential for secondary applications such as providing grid services is high. [ABSTRACT FROM AUTHOR]