1. Advancing the State-of-the-Art in Tire Testing The Tire Society September 21, 2010 Camber Ridge, LLC Dr. James F. Cuttino, President jcuttino@camberridge.com www.camberridge.com 704-575-1688

2. Camber Ridge, LLC Agenda Motivation for Examining Current Capabilities Lab-Based Tire Testing On-Road Tire Testing Pros and Cons A Design Proposal Conclusions MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN 2

3. Camber Ridge, LLC Motivation FMVSS 126 Protocol for Electronic Stability Control 100% Compliance by September, 2011 Current development relies heavily on prototype testing on proving grounds Each prototype vehicle = $500,000 (passenger car) 50 - 100 prototypes to production NCAP Rollover Protocols Similar developmental costs In summary, need to simulate extreme maneuvers Requires dynamic inputs in slip angle, loads, camber Simulations rely on projected curves and extrapolation 3 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

4. Camber Ridge, LLC Motivation Heavy Truck Industry –Few facilities can handle size / high loads (10,000 - 15,000 lbs normal) –High torque requirements –Durability testing –Tire harmonics –Rolling Resistance / Fuel Economy –Pending regulations for electronic stability control –Impact of customer-specified options (including tires) on vehicle compliance with regulations –New regulations for stopping distance 4 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

5. Camber Ridge, LLC In-Lab Testing Systems Akron Standard (early 1900’s) 5 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

6. Camber Ridge, LLC Subtleties of Design Freudenmann, T., Unrau, H.-J., and El-Haji, M., ‘‘Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements,’’ Tire Science and Technology, TSTCA, Vol. 37, No. 4, October – December 2009, pp. 254-278. Care required not to introduce parasitic errors 6 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

7. Camber Ridge, LLC In-lab Testing Systems Prüfstand für Fahrzeug/Fahrbahn Federal High- way Research Institute (BASt), Germany 7 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

8. Bristol (concrete)Atlanta Camber Ridge, LLC Modeling the Surface (Samples from Race Tracks in the US) Talledega Darlington Texas Concord 80 Grit Sandpaper 8 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

9. Camber Ridge, LLC On-road Testing Systems 9 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

10. Camber Ridge, LLC GM Tire Cornering Test Vehicle Cortese, A.D., and C.S. Rockafellow, “General Motors Proving Ground Tire Cornering Test Vehicle”, SAE Transactions, 1971-02-01, Paper 710092 Correction Wheel 5th Wheel Sensor Correction Wheel Test Wheel 10 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

11. Camber Ridge, LLC On-road Testing Systems 1972 - Michelin PLR Citroën components, two small-block Chevrolet 350 V- 8s, one to drive test tire, other to power the vehicle. 11 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

12. Camber Ridge, LLC Current In-lab Systems Pro’s –Controlled environment –Good Repeatability –Historical Data Pool –Industry Standard –24-7 Operation Con’s –Simulated road surface - concerns on accuracy –Load limits, depending on application –Torque magnitude and control –Limits on wet traction studies, etc. 12 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

13. Camber Ridge, LLC Comparison of Belt vs. Asphalt Increasing Slip M. G. Pottinger, G. A. Tapia, C. B. Winkler, and W. Pelz, "A Straight-Line Braking Test for Heavy Duty Truck Tires," Paper No. 45, ACS Rubber Division, Cleveland, OH, 10/17-20/95, published in Rubber World, Vol. 214, No. 6, September 1996, pp. 29-36. 13 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

14. Camber Ridge, LLC Comparisons of 2 Belt Coatings M. G. Pottinger, G. A. Tapia, C. B. Winkler, and W. Pelz, "A Straight-Line Braking Test for Heavy Duty Truck Tires," Paper No. 45, ACS Rubber Division, Cleveland, OH, 10/17-20/95, published in Rubber World, Vol. 214, No. 6, September 1996, pp. 29-36. 14 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

15. Camber Ridge, LLC Belt vs. On-road Results M. G. Pottinger, G. A. Tapia, C. B. Winkler, and W. Pelz, "A Straight-Line Braking Test for Heavy Duty Truck Tires," Paper No. 45, ACS Rubber Division, Cleveland, OH, 10/17-20/95, published in Rubber World, Vol. 214, No. 6, September 1996, pp. 29-36. Belt MachineOn-road Trailer 15 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

16. Camber Ridge, LLC Comparison of 3 Common Lab Configurations Freudenmann, T., Unrau, H.-J., and El-Haji, M., ‘‘Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements,’’ Tire Science and Technology, TSTCA, Vol. 37, No. 4, October – December 2009, pp. 254-278. MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN 16 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

17. Camber Ridge, LLC Rolling Resistance Flat Hydrodynamic Bearing, 1.71 m Drum, 2.0 m Drum Freudenmann, T., Unrau, H.-J., and El-Haji, M., ‘‘Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements,’’ Tire Science and Technology, TSTCA, Vol. 37, No. 4, October – December 2009, pp. 254-278. Discrepancy largest for 2.0 m drum 17 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

18. Camber Ridge, LLC Current On-road Systems Pro’s –Realistic operating conditions –Ability to study affects such as temperature –Control over surface and profiling (asphalt, concrete, cleats, etc.) –Wet traction, snow, other Con’s –Repeatability dependent on ability to control environment –Compliance of system limits loads –Metrology frame coupled with load frame –Dependence on driver variability –Limited throughput 18 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

19. Camber Ridge, LLC Braking Results vs. Track Location Treichel and Drahne, Tire Tests with a New Tracking System for Passenger Cars, SAE 880581, 1988. Uncontrolled Braking PositionBraking Position Controlled 19 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

20. Camber Ridge, LLC Effect of Temperature on Braking Performance Treichel and Drahne, Tire Tests with a New Tracking System for Passenger Cars, SAE 880581, 1988. Increasing Temp 20 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

21. Camber Ridge, LLC Opportunities for Improvement Limitations to existing technologies: –Generally limited to quasi-static testing conditions –Limited load ranges, particularly for belt machines –Limited torque applications in driving / braking –Generally simulated surfaces (drums, belts, abrasive surfaces) –Often restricted to lower speeds –Open loop operation forces dependence on carpet plots and lookup tables for dynamic simulations 21 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

22. Camber Ridge, LLC Opportunities for Improvement Opportunities to advance state-of-the-art –More realistic interface –Wet traction, off-road (military), etc. –Dynamic input –High torque braking (heavy truck, aircraft) –ABS braking / system analysis –Long distance wear studies –Rolling Resistance –Drift and Pull –Hardware in the Loop Capabilities 22 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

23. Camber Ridge, LLC “Ideal” Design Approach Contact Interface rules - protect at all costs. Simplify design as much as possible. Separate load loops from metrology loops where possible and appropriate. Consider modularity, flexibility. Control environment while providing variability. Minimize special order components. 23 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

24. Camber Ridge, LLC “Ideal” Design Approach –Accuracy vs. Repeatability Each has its place –Resolution / Sensitivity High loads and torques vs. Rolling resistance, drift and pull, uniformity –Constraints and actuation Force Inputs - downforce, torque, Fx, etc. Displacement Inputs - Yaw Angle, Camber Angle, Steer Angle –Rigid constraints critical for controlled, displacement based inputs 24 MOTIVATIONLAB-BASEDON-ROADPROS/CONSDESIGN

25. Camber Ridge, LLC Conclusion Tire Testing has advanced significantly over the years Advances have been incremental, following two fairly distinctive paths Understanding the history of tire testing provides a strong foundation for developing the next generation of testing capabilities Next meeting of the Camber Ridge Consortium is in late October 25

26. Camber Ridge, LLC