Finding Coefficient of Friction Using Three Directional Load Cells

Now more than ever, safety is one of the most important aspects of vehicle manufacturing. Advanced Driver Assistance Systems (ADAS) continue to improve, making vehicles safer every year. Sensors and systems for braking, traction control, and handling help drivers maintain control both on and off the road. A problem that arises in vehicle manufacturing and testing is measuring the traction between tires and roads. A popular method for estimating tire-road coefficient of friction is the “Magic Formula”, a formula to analyze tire characteristics using four dimensionless coefficients; however, it fails to consider camber, turning, or lateral motion.

Michigan Scientific is constantly striving to help improve the industry with our diverse range of products, each with their own variety of applications. Our Three Axis Load Cells have a vast array of capabilities: motorcycle axle and suspension force measurements, force measurements at the vehicle tire patch, force sensors for feedback control of test stands, and more. Recently, we noted the potential to use these loads cells for use in determining the coefficient of friction.

Coefficient of Friction Testing

Being able to accurately measure forces on tires and vehicles allows engineers to better determine how vehicles are affected by slipping. With a better sense of what leads to the max coefficient of friction, Engineers can better program the wheel slip control. This knowledge will help create more opportunities to improve ADAS, which leads to braking and vehicle control becoming safer.

Test Setup

A single load cell can measure three axes simultaneously and allows users to simulate and measure cornering. Three Axis Load Cells are capable of being mounted to both the input and reaction side of traction testing. The tire forces are measured with a load cell connected to the axle, while positioning a load cell beneath the test surface allows the road surface forces to be measured. The compact size of our load cells allows for easy mounting on test fixtures in small spaces. Michigan Scientific Three Axis Load Cells are available in a variety of load ranges, allowing tests to range from small sample materials to construction and agriculture vehicle tires.

Michigan Scientific works continuously toward providing the most accurate and convenient tools to help customers. Discovering new and innovative applications for our product is another way we accomplish this. Contact a Michigan Scientific engineer if new testing applications or questions about this application arise.