Research On Heave-heeling Decoupling Control Of Air Cushion Vehicle

As a new type of high performance vessel, the air cushion vehicle plays an important role in civil transportation and military application. It is through the fan to the bottom cushion gas, forming high pressure air cushion to support the weight of the vehicle and to make the vehicle sail in the suspended above the surface. Therefore, ACV has the characteristics of high speed, good seakeeping, amphibious etc.However, due to the high-speed air cushion vehicle sail of the surface of the water and lack of water rotary device, in turning operation is easy to sideslip and heeling, impacting the cushion performance. While ACV sailing in waves, due to the constant change of air cushion pressure, in a greater vertical acceleration at the same time, it would also produce heeling moment and change heeling gesture. In short,there is always a coupling effect between the heave and the heeling degrees of freedom, in order to improve the performance of the cushion, the research on the decoupling control of the heave and heeling of air cushion vehicle is needed.In this paper, the decoupling control method of the heave and heeling of air cushion vehicle is ADRC, which is a direct decoupling control method based on the model. Firstly,the mutual coupling control channel is decoupled into an independent channel,and then the Active Disturbance Rejection Controller is designed for the decoupled channel. The whole research process is as follows:Firstly, the fixed coordinate system and the hull motion coordinate system are established, and the conversion relation between them is obtained by the rotation transformation. Then, the force and moment of each part of the ACV are obtained by the method of separation model. The differential equation of the six degree of freedom of the air cushion is obtained by the momentum theorem and the momentum moment, and the dynamic model is established. Using direct and steady rotary simulation test of the ACV established mathematical model is verified.Secondly, the mathematical model of the complex lifting system is modeled separately.It consists of three parts: the pressure flow model of the pad, the volume change model of the air cushion and the discharge model of the apron. The air cushion pressure and fan pressure of the mathematical model of the cushion lift system with the multi-dimensional Newton iteration method. And the introduction of the heave stability and damping coefficient to analyze the static cushion rise of the ACVThen, the ADRC (Active Disturbance Rejection Controller, ADRC) of this paper were introduced,which is composed of four parts: Derivative tracker arrangements of the transition process (Tracking Differentiator, TD), disturbance estimated ESO device(Extended State Observer, ESO), non-linear error feedback control law (Nonlinear Error Feedback, NLEF), and the final dynamic linear compensation.Finally, the active disturbance rejection control technique is applied to the decoupling control of the multivariable system. The standard form of the multi variable system active disturbance rejection decoupling control is obtained by the analysis of the decoupling process. The mathematical model of the heave and heeling of the ACV is simplified,and then it is transformed into a standard form which is in accord with the active disturbance rejection decoupling control. Then the ADRC is used to decouple the heave and heeling of the ACV.