Digital Twin Modeling of Electro-Hydraulic Asymmetric Actuator System with Parameters Identified under High-Speed Conditions

The electro-hydraulic asymmetric actuator system is widely used in high-precision fields such as aerospace, robotics, and exoskeletons. As application scenarios evolve toward higher speeds and greater precision, the nonlinear characteristics and multi-physics coupling behavior of these systems become increasingly prominent. The accuracy of their modeling and identification directly impacts the effectiveness of system dynamic performance evaluation, control strategy design, and predictive optimization. Therefore, this paper combines the system structure and transmission characteristics to carry out digital twin modeling and parameter identification research under high-speed conditions. First, a coupling model based on motor-load characteristics and flow characteristics is established; then, the least squares method is proposed to identify the frequency domain Bode response of the motor-controlled pump system and the time domain nonlinear parameters of the hydraulic transmission system; finally, the two models are organically combined to establish a Simulink-AMESim co-simulation model, and the accuracy of the constructed nonlinear model is verified through simulation and experimental comparison. The experimental results show that the speed response error is within 0.5%, and the position tracking error is within 0.5mm. This method can accurately model the electro-hydraulic asymmetric actuator system under high-speed conditions.