Small Vehicle Dynamometer

A dynamometer serves to measure power and torque. In our case, these measurements will be taken at the wheels of the SAE Baja vehicle. This gives the University of Wyoming Baja Racing Team a way to quantify their vehicle's potential. While engine size used in the Baja vehicle is constrained (10 horsepower), actual torque delivered to the wheels may vary due to drivetrain efficiency. Currently, industry does not supply a dynamometer for this class of small vehicles. Our senior design project aims to design and construct a chassis dynamometer that assists in design and tuning of the drivetrain and other necessary components for this year's and future Baja vehicles. Our chassis dynamometer includes a stand that supports the vehicle and a single mechanical friction brake to apply load at one wheel. A load cell placed beneath the brake caliper measures force generated by the torque delivered to the wheels. RPM at the engine and the wheels is measured using a magnetic proximity sensor. Measured force multiplied by the distance between the center of rotation and load cell position, gives torque. Once known, wheel speed and torque are used to calculate the power delivered to the wheels. Closed loop electronic control was applied to engine throttle and applied brake load to automate testing.