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Dynamic Research, Inc. PRELIMINARY EVALUATION OF REGULATION 78-ANNEX 4APPENDIX DETERMINATION OF TEST TRACK SURFACE FRICTION This document is confidential and proprietary, and it is not to be released to anyone without the permission of Dynamic Research, Inc. 355 Van Ness Ave • Torrance • California 90501 • 310-212-5211 • Fax 310-212-5046 • www.dynres.com Dynamic Research, Inc. OBJECTIVES - SURFACE FRICTION MEASUREMENTS • Accomplish measurements of available surface friction for use in "utilization of adhesion" ABS tests • Measurement of “K” according to ECE R78 Annex 4 Appendix with: – 4 test riders – 3 ABS motorcycles, ABS disabled • Measurement of “Peak Braking Coefficient” based on ASTM E1337 Procedure. This is consistent with ISO 8349 2 Dynamic Research, Inc. SURFACES • High friction pavement • Low friction sealed wetted surface 3 Dynamic Research, Inc. RIDERS • Ideal test rider for purposes of R78-ann4-app would be: – Able to consistently perform braking maneuvers at the limits of adhesion – Able to recover when limits of adhesion are exceeded – Able to follow instructions even when they are complex – Experienced in the test being conducted – Objective in interpretation of instructions • Characteristics of riders used for this study – Experience with engineering evaluations of vehicles (3/4) – Highly skilled motorcycle riders (4/4) 4 Dynamic Research, Inc. RIDERS (cont‘d) • Rider 1: Engineer, experienced amateur racer • Rider 2: Engineering test rider with previous experience in braking evaluations and with motorcycle road racing • Rider 3: Engineering test rider with previous experience in braking evaluations and with extensive motorcycling experience • Rider 4: Experienced amateur racer and professional race instructor, experienced in teaching limit braking skills 5 Dynamic Research, Inc. MOTORCYCLES • BMW R1200 GS – Partially integral combined brake system: hand lever operates F&R brakes, foot pedal operates R brake – ABS off switch • BMW R1200 RT – Partially integral combined brake system: hand lever operates F&R brakes, foot pedal operates R brake • BMW K1200 LT – Fully integral combined brake system: F&R systems both activated by either hand lever or foot pedal • For K measurements, ABS was disabled on all motorcycles 6 Dynamic Research, Inc. INSTRUCTIONS TO TEST RIDERS FOR K MEASUREMENT In order to maximize reproducibility: • Used R78-ann4-app to the extent feasible • Some “clarifications” were needed in order to make the instructions more clear and less ambiguous • Some “variations” were in order to study the effects of “maximum control force” and “non-constant control force” • Riders were reminded to avoid capsize 7 Dynamic Research, Inc. BASELINE INSTRUCTIONS (deviations from R78 are marked in red bold) 1. DETERMINATION OF THE COEFFICIENT OF ADHESION (K) FOR PURPOSES OF VERIFYING THE TEST SURFACES 1.1. The coefficient of adhesion shall be determined from the maximum braking rate, without wheel lock, of the vehicle with the anti-lock device(s) disconnected and braking both wheels or systems simultaneously. [1]/ 1.2. Braking tests shall be carried out by applying the brakes at an initial speed of about 60 km/h (or, in the case of vehicles unable to attain 60 km/h, at a speed of about 0.9 Vmax) to a stop with the vehicle unladen (except for any necessary test instrumentation and/or safety equipment). As constant a force as is practicable must be used on each brake control throughout the tests. 1.3. A series of tests may be carried out up to the critical point reached at incipient wheel(s) lock by varying both the hand and the foot brake control forces, in order to determine the maximum braking rate of the vehicle. [2]2/ 8 Dynamic Research, Inc. NON-CONSTANT FORCE INSTRUCTIONS (deviations from R78 are marked in red bold) 1. DETERMINATION OF THE COEFFICIENT OF ADHESION (K) FOR PURPOSES OF VERIFYING THE TEST SURFACES 1.1. The coefficient of adhesion shall be determined from the maximum braking rate, without wheel lock, of the vehicle with the anti-lock device(s) disconnected and braking both wheels or systems simultaneously. [1]/ 1.2. Braking tests shall be carried out by applying the brakes at an initial speed of about 60 km/h (or, in the case of vehicles unable to attain 60 km/h, at a speed of about 0.9 Vmax) to a stop with the vehicle unladen (except for any necessary test instrumentation and/or safety equipment). 1.3. A series of tests may be carried out up to the critical point reached at incipient wheel(s) lock by varying both the hand and the foot brake control forces, in order to determine the maximum braking rate of the vehicle. [2]2/ 9 Dynamic Research, Inc. BRAKING RATE CALCULATION Speed from Radar sensor (km/h) Z v / gt 0.56 / t 60 40 20 t Time (sec) 10 Dynamic Research, Inc. RESULTS Surface Friction K Measurements Rider Using “Constant” Braking Force, as required by R78 Best 3 runs selected for each rider Brake Both Both Both Both Both Both Surface Motorcycle High High High Low Low Low R1200 GS R1200 RT R1200 LT R1200 GS R1200 RT R1200 LT Mean Std Dev 0.695 0.793 0.608 0.278 0.336 0.313 0.103 0.206 0.119 0.096 0.115 0.053 11 Dynamic Research, Inc. RESULTS Surface Friction K Measurements Rider Using “Non Constant” Braking Force Best 3 runs selected for each rider Brake Surface Motorcycle Mean Std Dev Both Both Both Both Both Both 0.778 0.924 0.672 0.346 0.386 0.400 0.083 0.084 0.035 0.102 0.089 0.032 High High High Low Low Low R1200GS R1200 RT R1200LT R1200GS R1200 RT R1200LT 12 Dynamic Research, Inc. RESULTS Surface Friction PBC Measurements (ASTM E1337) High mu at start of Phase I Individual Samples 1.011 1.003 0.988 0.954 1.046 0.974 1.016 0.994 0.972 0.955 0.920 0.994 Mean 0.979 0.983 0.931 0.933 0.985 Standard Deviation 0.034 High mu at end of Phase I (night time, surface possibly damp) Individual Samples 0.946 0.901 0.890 0.851 0.882 0.857 0.919 0.939 0.940 0.946 0.919 Mean 0.908 Standard Deviation 0.035 13 Dynamic Research, Inc. RESULTS Surface Friction PBC Measurements (ASTM E1337) Low mu at start of Phase I Individual Samples 0.531 0.437 0.516 0.529 0.533 0.521 0.470 0.522 0.434 0.538 0.424 0.427 Mean 0.504 Standard Deviation 0.041 Low mu at end of Phase I Individual Samples 0.505 0.554 0.507 0.542 0.471 0.484 0.550 0.505 0.526 0.462 0.510 Mean 0.507 0.492 0.487 0.507 0.474 Standard Deviation 0.030 14 Dynamic Research, Inc. RESULTS Surface Friction PBC Measurements Example Raw Data from PBC Test 15 Dynamic Research, Inc. RESULTS Surface Friction PBC Measurements Example Raw Data from PBC Test 16