The Research And Implementation On Vertical Pneumatic Control Of Air Bearing Testbed

Nowadays the development of technology is advancing rapidly. With the implementation of the US Apollo program and China’s Chang E moon program, countries intensified competition for space resources. In this environment, it put forward higher requirements on the quality of the spacecraft, which deeply highlights the importance of a full physical simulation system. In this paper, we research the vertical movement of the all-physical simulation system.Firstly, we discuss the characteristics and the technical difficulties of the vertical movement control method of the air bearing testbed. Combined with the actual control of the project environment, the whole control process is divided into two major steps, the displacement control and the pressure track. We outline the two-step control flow. Then it analyses the mechanical and aerodynamic about the most important part of the control system- the proportional valve and the control cavity, and we get a detailed system model.Secondly, the displacement control is studied. Combined with the actual characteristics of the vertical movement, it develops higher control requirements of the rapidity and overshoot about the vertical movement. In order to solve the contradiction between speed and low overshoot, the displacement controller was designed based on the composite nonlinear feedback control. And the functions of the parameters about the composite nonlinear feedback control are discussed through the simulation. Finally, the extended state observer of the ADRC was designed, and we verify the superiority of control.Thirdly, the pressure tracking research is done. It analyzes that the pressure tracking control system is a non-linear multi-interference control system. And the sliding mode variable structure control method is put forward. A detailed analysis of the sliding mode control about the completely robust reasons was done. The different approaches laws were compared through simulation. Finally the highlighted flaws-buffeting about the sliding mode control was analyzed and proposed solutions which had been verified by simulation.Finally, the vertical motion control system hardware and software was designed for the flotation units. Hardware consists of an industrial computer, sensors, signal acquisition card, actuators and wireless transmission components. Software mainly uses embedded real-time operating system as a development platform, improved real-time system processing, and designed a user interface for observing the information of the control flow feedback intuitively. Finally, a practical engineering test has been done to achieve the desired control requirements.