Torque meters for calibration of roller testing systems

BEP Europe in Bruges, a manufacturer of testing systems for assembly lines in the automotive industry, utilises HBK’s range of HBM T40B torque meters and a TIM-PN measurement amplifier for the calibration of braking forces in new test benches.

To minimise the error margin of the measurement data as much as possible, BEP has defined a precise procedure for calibration/verification. The manufacturer of test benches uses the measured values of HBK’s torque meters as a reference value for the roller test benches.

As part of Burke E. Porter (BEP) Group, BEP Europe is a manufacturer of testing systems for assembly lines, that are supplied to the plants of practically all the well-known automotive brands. The testing systems are set up at the end of the production lines for the testing and adjustment of various vehicle parts and functions, including brakes, suspension and road handling. They adjust lighting, wheel alignment and test sensors for Advanced Driver Assistance Systems (ADAS), Adaptive Cruise Control (ACC), Head-up Display (HuD) and assisted parking.

Frank Verschuere, supervisor of the automation department within BEP said: “The roller test benches are equipped with four sets of rollers for four wheels so that a car wheel sits between two rollers. Each set of rollers is driven by an electric motor. For each set we measure the force brought to bear by the electric motor on the car tyres, so that we can measure both the car’s power and the braking force. We also have to take into account the mechanical frictional losses and electric losses in the electric motor.”

The test benches and testing procedures are developed according to the end customer’s specifications. For every test function a calibration procedure has been developed, to minimise the error margin of the measurement data as far as possible. Within the test benches the HBM torque meters are used for the calibration of braking forces. Since 2002 the T10F torque measurement readers and the MP60 measurement amplifier have also been used. 

Recently, BEP Europe switched to the T40B and the TIM-PN measurement amplifier, which – used together – constitute a complete digital torque measurement system. HBK’s tools were chosen because of the data processing speed and accuracy of the HBM torque measurement sensors.

“Every roller test bench is subject to calibration after assembly and subsequently at periodic intervals,” said Yann Germain, Technical Quality Manager at BEP Europe. “Once the measurements have been executed in accordance with the prescribed procedures, the torque measurement sensor is fitted onto the electric motors’ drive. By verifying and calibrating our measurements using an HBM sensor, we know whether the set measured values of our roller test benches fall within the tolerances. The testing systems are also re-calibrated if it turns out that deviations appear in the vehicles’ measurement results.”