Magneto-rheological Fluid Mount Based On Squeeze Model And Enigne Vibration Isolation Control System

Engine is a widely used thermal power machinery, the vibration of which is one of the main vibration source of vehicle(cars, ships, aircraft, etc.). Engine has a wide frequency, multi-sources and multi main frequency vibration when it runs. It not only affect normal work of equipments and instruments on the vehicles, but also decrease riding comfort, and have a serious effect on surrounding environment, and even cause serious property and lives damage. Mounting system can reduce the energy to the launch vehicle transmitted from the engine. The rubber mount and hydraulic mount are used generally at present, which can not meet the isolation requirements in a wider frequency range. So the semi-active mount based magnetorheological fluid(MRF) is studied extensively. A four-cylinder in-line diesel engine is taken to study in this paper; mechanical model and magenetic circuit design of MRF mount is discussed; the engine vibration isolation system is simulated; the PID and human-simulated intelligent control(HSIC) methods are studied; and the test is carried out on the engine vibration bench. The specific work is as followed:â‘ For small displacement of engine vibration, a kind of MRF mount based on the model of disk squeeze is designed and produced. Navier slip condition and boundary compatible condition are established, radial velocity and radial pressure distribution of different location under extrusion are derived. The interface between Newtonian flow area and Bingham flow area is determined, the mathematical expression of stress between two disks changed with the current was calculated. The experimental damping force is in accordance with the theoretical value under the test on MTS870 Electro-hydraulic servo excitation console.â‘¡The exciting force and torque of the four-cylinder in-line diesel engine are analyzed. So the main vibration exciting sources of engine are second order reciprocating inertia force and overturning moment, and the force of the incentives is estimated. According to Lagrange equation, the two freedom degrees dynamic model of engine vibration isolation system based MRF mount. Influence of force transmission rate by frequency ratio and damping is analyzed, and the range of stiffness is estimated.â‘¢The dominant ideology of HSIC is to study and simulate human control functions based on control structure macro-scale on human. For vertical vibration and overturning around the output shaft, the PID and HSIC methods are designed and simulated. It shows that the HSIC has a good isolation effect.â‘£The engine vibration isolation test and control system is built using the engine test platform in Chongqing jiaotong university. Using CompactRIO (reconfigurable compact input and output ) embedded real-time controller of NI Company, the data acquisition and real-time control programs are compiled. Vibration isolation control of engine is carried out in different conditions and then the data of PID and HSIC based on MRF mount is analyzed and processed. The results show that the HSIC has good isolation performance in the low and high frequency.