^Title Torque Measurement Using Wireless Technology

The team designed a new differential assembly for the 2011 prototype. Theoretical calculations are always a good approach when designing from scratch. However, validation and data acquisition are a must for the development.

The team needed to monitor the behaviour of the system as, initially, there were a few concerns. Typical strain gauge installation was not an option for the measurement of torque transmitted to the driveshaft because of rotation. The required wireless data transmission couldn’t even be partly stationary (e.g. the receiving antenna) as the shaft is always moving. Finally, the shape and physical packaging of the rear of the car did not provide easy installation of a wireless data transmission system.

To begin with technicians installed strain gauges on each driveshaft. They connected these to a strain gauge to radio telemetry T24-SA transmitter. A machined short cylinder, acting like a holder for the transmitter and the battery, mounted on the driveshaft. The team installed the T24-AO1 wireless receivers on a bracket near the transmitter for better signal transmission. They then connected these to the car’s data acquisition system (Motec ACL). Engineers required a calibration to convert the electric signal into a known torque. To obtain this, they used a lever supporting a known weight to apply the desired torque.