Pulley´s clamping force and axial position measurements for electro-mechanical continuously variable transmission in automotive applications

This paper presents clamping force and axial position measurements of secondary pulley clamping force actuator for Electro-mechanical Dual Acting Pulley (EMDAP) Continuously Variable Transmission (CVT). From these measurements, the relationship between axial position and clamping force in the range of 0 to 20 kN is established. A force sensor is placed between two movable pulleys to measure the clamping force, while an incremental encoder of 500 pulses per revolution is attached to the pinion shaft to indirectly measure the axial pulley position. Measurements are done using Matlab/Simulink© program and Arduino Uno based data acquisition system. The experimental results show that when the clamping force is between 0 and 10 kN, the relationship between clamping force and axial position can be approximated using third-order polynomial equation with an average error of 0.35%, while between 10 kN and 20 kN, the relationship can be approximated using a linear equation with an average error of 0.02%. Based on this relationship, the calibrated position sensor could be used to replace the force sensor to indirectly measure the pulley clamping force.