MRI: Acquisition of Automotive Tire Force and Moment Sensors

Bucknell University, Lewisburg PA

Investigators

Abstract

Significant investments are being made in intelligent roadway infrastructure; manufacturers are deploying increasingly advanced driver assistance systems; and researchers are racing to develop reliable autonomous vehicles that can take over the task of driving entirely. Despite these remarkable advances fundamental research is needed to develop accurate models of overall vehicle dynamics and potential feedback control for future autonomous and smart vehicle systems. To function effectively, autonomous vehicles must accurately sense and respond to changing roadway conditions. By supporting the acquisition of instrumented wheels-- to provide real-time data generated by the tires interacting with the road surface-- this Major Research Instrumentation award will contribute to U.S. competitiveness in the quickly evolving international automotive sector. These data will allow researchers at Bucknell University, Penn State University and other institutions to conduct experiments, share data and collaborate with others to develop algorithms to determine road conditions from sensors. The improvement in fundamental understanding of the interaction of individual tires operating in-situ with the road will enable continued advances in vehicle control, autonomous vehicle operation, and intelligent roadway systems. The instrumented wheels supported by this award are designed to capture all six forces and moments that are generated by the tire interacting with the road. A custom-manufactured adapter provides physical connection between the wheel rim and load cells, which in turn transfers tire forces and moments to the vehicle chassis. Wheel forces up to 24 kN and torques up to 7.2 kNm, which represent tire behaviors beyond even the most extreme skidding, can be measured with less than 0.1% error. The sensors will be installed on a drive-by-wire research vehicle with computer-controlled independent front steering and independent rear drive. The vehicle is instrumented with a dual-antenna GPS and inertial measurement sensors that provide measurements of the vehicle kinematics. By comparing wheel force and moment data to steering torque inputs, model predictions, vehicle motion measurements, and pavement measurements, the instrumented wheels enable advanced actuation strategies and unique methods of identifying road surface friction conditions. These data will enable designers to develop adaptive control systems that allow autonomous vehicles to better sense road conditions and to optimize the modeling and use of steering and braking inputs to improve vehicle safety, performance, and efficiency.