Parameter Adaptive Sliding Mode Force Control for Aerospace Electro-Hydraulic Load Simulator

Abstract

The aerospace electro-hydraulic servo simulator is used to simulate the air load received during flight, and is used for the performance test and acceptance test of aerospace servo actuators on the ground. The force loading accuracy of the load simulator is an important assessment index. Because the loading system and the actuator system to be tested are coupled together, the free displacement of the system to be tested during loading will bring huge disturbance to the loading system, thus how to suppress external interference has always been a hot issue in the control field. This paper addresses this issue under the influence of nonlinear friction and uncertain external disturbance. First, the exact mathematical model of the system is derived, and the characteristics of the system are described by the state equations. Second, in order to obtain the relevant parameters in the controller, the system parameters are identified. Third, the parameter adaptive sliding mode force control based on the reaching law is proposed, and the performance of the control algorithm is analyzed theoretically. Finally, the new control method is applied in the aerospace electro-hydraulic servo simulator, and the results show that the new control algorithm can suppress the external interference by 95% or more, and the control accuracy is more than 97%, which fully demonstrates the effectiveness of the control method.

Study on High-Precision Tension Control Technology for a Cold-Rolling Pilot Mill with Hydraulic Tension

“…Jing Huang et al derived the exact mathematical model of the control system, proposed the parameter-adaptive sliding-mode force control based on the reaching law and carried out experimental research. Their results fully demonstrated the effectiveness of the control method [12]. Guichao Yang and Jianyong Yao proposed an innovative multilayer neuroadaptive controller to further improve the output force tracking performance of electro-hydraulic load simulators with uncertainty rejection, where closed-loop stability is guaranteed, and extensive comparative application results were achieved [13].…”

Terminal Sliding Mode Force Control Based on Modified Fast Double-Power Reaching Law for Aerospace Electro-Hydraulic Load Simulator of Large Loads

“…Theorem 1. For the aerospace electro-hydraulic load simulator (22), including the bounded displacement disturbance and the strong phase lag, under the controller as shown in Equation ( 35), the force tracking error of the simulator can converge to a small neighbor range of the system's equilibrium point in finite time, and the system is asymptotically stable.…”

“…In a research study, a finite-time sliding mode control based on the modified GMS friction model, which is identified by PSO, has been designed to acquire an accurate system model and compensate for uncertain disturbances and nonlinear friction, ensuring the dynamic performance and static precision of the loading system, while achieving a finite-time convergence [19]. Parameter estimation [20,21] and identification [22], aimed at system uncertainties and nonlinear disturbances, integrated into a sliding force control model, is adopted to eliminate parametric uncertainties, which strengthens the system's robustness, as well as exhibiting a strong anti-interference ability and loading accuracy. Based on a proposed disturbance coupled model containing mechanical backlash, a decoupled position interference and mitigated oscillation caused by the backlash are achieved by the control strategy of an almost disturbance decoupling.…”

State and Disturbance Observer based Robust Disturbance Rejection Control for Friction Electro-Hydraulic Load Simulator

“…where t V is the total control volume (m 3 ), e  is the volume elastic modulus of oil, p A is the effective area of the hydraulic cylinder piston (m 2 ), ct C is the equivalent leakage coefficient.…”

“…The electro-hydraulic load simulator has the capability to replicate intricate loads in laboratory settings, which finds extensive application in evaluating the performance of advanced servo mechanisms [1][2][3][4]. Nevertheless, the accuracy of load simulation is hindered by motion disturbances arising from the tested servo mechanism, thereby posing a significant challenge [5][6][7][8][9]. To address this issue and enhance load reconstruction precision, researchers have developed a pioneering friction electro-hydraulic load simulator (FEHLS) [10,11].…”