Experimental Vibration Simulation for Heavy Duty Vehicle Seat Suspension with a Multiple-DOF Motion Platform

This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one. For estimating the displacement accurately, a double integration approach in the frequency domain is applied to the measured acceleration after it is calibrated using the static phase acceleration data. The experimental results of two different sine wave vibrations show that the desired motion profile of single-frequency vibration and the estimated displacement can match very well. The estimated z axis displacement of a vehicle through a speed bump is scaled down in magnitude by a quarter and implemented in the motion platform. The estimated displacement matches the trend of the real vehicle bump vibration. All the test results confirm that this 6-DOF motion platform can emulate the real vehicle vibration and can be applied to the multi-DOF vibration analysis for a heavy duty vehicle seat suspension in lab.