With technological advances and industrial upgrading, high-performance equipment has put higher demands on the performance of electro-mechanical actuators. With a view to making electro-mechanical actuators more reliable and integrated, firstly, an integrated electro-mechanical actuator module (IEMM) with multiple structural forms was proposed in this paper, and a comparative analysis was performed on the characteristics of different transmission schemes. Then, the feasibility of manufacturing the IEMM’s main bearing components using Carbon Fiber Reinforced Polymer (CFRP) with higher specific stiffness, specific modulus and specific strength was demonstrated by finite element simulation (FEA) software, in a bid to further reduce the weight of the IEMM. Next, a parameter estimation model, a heating power calculation model, and a thermal resistance calculation model were built, so that there is no need to rebuild the whole system model under different demand indexes. On this basis, a multi-objective optimization design model was built with light weight, low power loss, and high level of integration as optimization aims to achieve better comprehensive performance in the early design phase of the IEMM system. However, IEMM’s higher level of integration and its shell made of CFRP with a thermal conductivity of less than 5 W/m°C posed a challenge to the heat dissipation of the motor stator. Therefore, a thermal network model needs to be created in AMESim to evaluate the temperature of IEMM’s parts and components under different working conditions. Finally, the process of IEMM performance optimization design was described and improved, and performance optimization design was conducted by taking one of IEMM’s transmission schemes as an example.

Electro-hydrostatic actuators (EHAs) combine the advantages of electric and hydraulic actuation, and it results in a preferable solution for heavy load actuation. The required power level of the EHA is increasing because it is being introduced to large vehicles such as submarines and heavy launch vehicles. Thus, a 30 kW EHA is under development for launch vehicles, which simultaneously require high dynamic performance, light weight, high efficiency, etc. Therefore, a dedicated multi-objective optimization design method is proposed for the preliminary design of the 30 kW EHA. In this study, firstly, the design requirements were analyzed for the launch vehicle application, and the objectives and the constraints of the optimization design were defined for the 30 kW EHA. Secondly, dedicated models were developed for evaluating each objective or constraint, including weight, bandwidth, and efficiency. Thirdly, the multi-objective EHA optimization design was implemented based on the genetic algorithm. Lastly, the optimization design results were evaluated through simulation analysis, which demonstrated that the 30 kW EHA achieved more than 10 Hz bandwidth with under 72 kg weight while the efficiency was also optimized.