The Research On Air Cushion Pressure Control Methods Of ACV

Air Cushion Vehicle (ACV) is a high-performance ship，its hull is completely supportedby air cushion and fly on the water or ground. Air boosters provide power for ACV, it isamphibious. In the sailing process, pads liter pressure stability greatly affects handling andsafe navigation of the ACV, so the study for pressure control method has importantsignificance. PID control algorithm due to its simple practicality, it can be well applied inpressure control pad liter, but the traditional PID control method lacks adeptness, it is difficultto achieve good control effect.In this paper, the particle swarm optimization algorithm is proposed, based on improvedparticle swarm optimization algorithm, adaptive PID control method is brought out for ACVcushion pressure control. In order to solve the delay problem from the input to the output inACV’s cushion system, the paper introduces gray prediction model to forecast the next timecushion pressure to reach advance correction purposes. Little research exists at home andabroad about the ACV pressure control; this paper is the first time using such control methodfor the ACV cushion pressure. The paper is based on one ACV, to establish the six degrees offreedom mathematical model and air cushion system mathematical model. Cushion pressurecontrol system is studied out based on improved PSO-PID controller, which is based on graytheory. The specific contents are as follows:First, six degrees of freedom motion mathematical model is built for the Air CushionVehicle. The mathematical model is built for each part of the ACV, According to the theoremof momentum and moment of momentum theorem, six degrees of freedom motion equation isbrought out in a fixed coordinate system, and it is converted into a coordinate system, whichis suitable for the expression of the hydrodynamic and aerodynamic, and complete six degreesof freedom motion simulation model for the ACV. By direct flight characteristics androtational characteristics of simulation experiments, the paper verifies the correctness of themodel.Secondly, the mathematical model is built for air cushion system, the relation betweenflow and pressure is studied for each part of the air cushion system, and flow balanceequations are established. Through the experiments of heel and trim, simulation experimentsverify air cushion system mathematical model. According to the mathematical model for aircushion system, improved PSO-PID controller is designed based on GM (1,1) model. GM (1,1) model can predict the future cushion date according to the historical dates, it compare with the desired pressure date, the differential is as an input for improved PSO-PID controller.Based on the difference, particle swarm optimization algorithm tunes the three parameters ofthe PID controller.Finally, a simulation environment is established, which is as much as possible tomaintain with the real environment, in order to verify the effectiveness of the proposedcontrol method. Simulation experiments are carried out under different wave’s situations, andthe output value of the cushion pressure is tested, to compare with the original data withoutcontrol to verify effectiveness of such control method.