## 1 Introduction
Characteristics of swashplate control analysis with pressure compensation valve [14], design of a swash plate control mechanism [15], high frequency vibration of the swash plate near the equilibrium state [16], and the overall dynamic characteristics of the variable pump [17] are included in this research. Figure 1: (a) Aircraft engine driven pump; (b) Aircraft engine motor driven pump. Many scholars have studied pressure control of the hydraulic pump, [PERSON] et al. [18] studied the control problem of variable load and unknown load pressure, and a two-order nonlinear controller including feed forward and feedback control was designed. The stability of the pump control system was proved based on the Lyapunov theory, and the feasibility of the controller was verified by experiments. A mathematical model of an open-circuit pump was established by [PERSON] [19; 20], and the controller was established based on pressure compensating, load-sensitive control and torque control respectively. Experiments were carried out to verify the effectiveness of the controllers. [PERSON] [21] proposed for the first time not using any linearization or order reduction, and an adaptive and model-based discharge pressure control design for the variable displacement axial piston pumps (VDAPPs), whose dynamical behaviors are highly nonlinear and described by a fourth-order differential equation. A nonlinear supply pressure controller for a variable displacement axial piston pump was proposed in reference [22]. A load flow disturbance observer was proposed to deal with unknown and time-varying load flow. A nonlinear feed forward controller was derived using the differential flatness property of the system, and a feedback controller was implemented to stabilize the system. The adaptive control design to solve the trajectory tracking problem of a Delta robot with uncertain dynamical model was described in reference [23]. The output-based adaptive control was designed within the active disturbance rejection framework. New aspects of a recursive backstepping design methodology from both a theoretical and application point of view were explored in reference [24]. Three main topics such as control of multivariable nonlinear systems, steering control of light passenger vehicles and coordinated steering and braking control of commercial heavy vehicles were investigated from a backstepping perspective. In this paper, the control methods of pressure continuous regulation electrohydraulic proportional aviation axial piston pump(EHPAAPP) are considered to achieve the objectives of the following aspects: the response time of the electro-hydraulic proportional variable pump, which is defined as not exceeding 0.05 s during the process of pressure adjustment, the instantaneous peak pressure not exceeding 135% of the rated outlet pressure, the response time is not more than 0.05 s, and the stability time does not exceed 1 s.  
The paper is organized as follows: Section 2 discusses the feasibility of a pressure continuous regulation of EHPAAPP; Section 3 establishes its mathematical model and dynamic characteristics are analyzed. The PID control method, linear quadratic regulator (LQR) based on feedback linearization method and backstepping sliding control method are added to this nonlinear system in Section 4, and the contents of this paper are concluded in Section 5.