Research On Vehicle Multi-dimensional Vibration Isolation Platform Based On 4-UPS/UPU Parallel Mechanism

In the driving process of motor vehicle,vechicle vibration causesd by uneven road,the power plant,wheels,the transmissions system and the other rotating parts in the driving process of motor vehicle.Generally the uneven pavement is the main factor causing the vehicle vibration,which makes the vehicle equipment in the transport process subjected to multi-dimensional vibration and load shock from the ground and reduces the accuracy of the equipment or even affects the use of the equipment.Accordingly,in order to enhance the multi-dimensional vibration and load impact of the on-board equipment in the transport process,it is necessary to effectively isolate the vehicle-mounted equipment.In this paper,we use multi-dimensional vibration of vehicle equipment as the research background to study a 5-DOF vibration isolation system which based on parallel mechanism.In this paper we have analyzed the characteristics of the vibration type of the motor vehicle in the driving process,then we proposed a 4-UPS/UPU type five freedom parallel mechanism as a vibration isolation system based on the multi-dimensional vibration of vehicle equipment during transportation.By using the screw theory,the vibration isolation platform has three moving and two rotational five degrees of freedom and we use the vector method of 4-UPS/UPU dimensional vibration isolation system to conduct a detailed analysis of kinematics.The kinematics of the 4-UPS/UPU five-dimensional vibration isolation system was carried out by using the mathematics analysis software MATLAB to verify the correctness of the inverse kinematics solution.The working principle of MR damper is analyzed,and the selection of MR damper is applied to the branch of the vibration isolation system.The dynamic model of vibration isolation mechanism is established by using Kaine equation,and then we analyzed the vibration characteristics of the parallel vibration isolation mechanism and studied the transmission performance of the vibration isolation platform under the complex excitation environment.Through genetic algorithm,the parameters of the coefficient of stiffness coefficient,the damping coefficient and the vibration isolation quality of the branch spring in the transfer rate function are optimized and analyzed.Then the stiffness and damping of the parallel vibration platform were modeled with the undamped vibration equation was established to solve the fifth-order natural frequency.The natural frequencies of the vibration isolation are simulated by using SolidWorks and ADAMS,and the correctness of the theoretical calculation is verified.In order to eliminate the influence of the flexible deformation of the flexible deformation on the carrier equipment in the complex vibration environment,we made the rigid flexible coupling model of parallel vibration isolation mechanism.The vibration isolation performance of the parallel vibration isolation platform is verified by the experimental results of sinusoidal sweep excitation,pulse excitation and power spectrum.As can be seen from the simulation results,this thesis can effectively suppress the vibration of the upper platform.