THE INERTIAL EFFECT OF ACCELERATION FIELDS ON A SELF-DECOUPLED WHEEL FORCE TRANSDUCER

Abstract

WHEEL FORCE TRANSDUCER (WFT) IS A TOOL WHICH CAN MEASURE THE THREE-AXIS FORCES AND THREE-AXIS TORQUES APPLIED TO THE WHEEL IN VEHICLE TESTING APPLICATIONS. HOWEVER, THE TRANSDUCER IS GENERALLY MOUNTED ON THE WHEEL OF A MOVING VEHICLE, WHEN ABRUPTLY ACCEL-ERATING OR BRAKING, THE MASS/INERTIA OF THE TRANSDUCER ITSELF HAS EXTRA EFFECTS ON THE SENSOR RESPONSE SO THAT INERTIA/MASS LOADS WILL BE DETECTED AND COUPLED INTO THE SIGNAL OUTPUTS. THIS IS THE INERTIA COUPLING EFFECT THAT DECREASES THE SENSOR ACCURACY AND SHOULD BE AVOIDED. IN THIS PAPER, THE INERTIA COUPLING PROBLEM INDUCED BY SIX DIMENSIONAL ACCELERATIONS IS INVESTIGATED FOR A UNIVERSAL WFT. INERTIA LOAD DISTRIBUTION OF THE WFT IS SOLVED BASED ON THE PRINCIPLE OF EQUIVALENT MASS AND ROTARY INERTIA FIRST-LY, THUS THEN ITS IMPACT CAN BE IDENTIFIED WITH THE THEORETICAL DERIVATION. FEM SIMULATION AND EXPERIMENTAL VERIFICATION ARE PERFORMED AS WELL. RESULTS SHOW THAT STRAINS IN SIMULATION AGREE WELL WITH THE THEORETICAL DERIVATION. THE RELATIONSHIP BETWEEN THE APPLIED ACCELERATION AND INERTIA LOAD FOR BOTH WHEEL FORCE AND MOMENT IS THE APPROXIMATE LINEAR RESPECTIVELY. THE RELATIVE ERRORS ARE ACCEPTABLE WITHIN LESS THAN 5% AND THE MAXIMUM IMPACT OF INERTIA LOADS ON THE SIGNAL OUTPUT IS ABOUT 1.5% IN THE MEASURING RANGE.