Motorcycle ABS Testing Related to Draft GTR Phase II Results June, 2006 Dynamic Research, Inc. 355...

Motorcycle ABS Testing Related to Draft GTR

Phase II Results

June, 2006

Dynamic Research, Inc.

355 Van Ness Ave • Torrance • California 90501 • 310-212-5211 • Fax 310-212-5046 • www.dynres.com

This document is confidential and proprietary, and it is not to be released to anyone without the permission of Dynamic Research, Inc.

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TOPICS

• OBJECTIVES• DESCRIPTION OF TESTS• METHODS• TEST RESULTS• OBSERVATIONS• DISCUSSION


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OBJECTIVES

• Confirm the feasibility and practicality of the proposed test methods in– 4.9.3, ABS stops on high friction surface– 4.9.4, ABS stops on low friction surface– 4.9.7, ABS response to low to high friction

transition• Refine and clarify test procedures and

parameters so they are reproducible, repeatable• For the various motorcycles and riders, compare

surface friction measurement K to ASTM method • Make observations of the response of the

various motorcycles relative to the proposed criteria– Stopping distance and MFDD– No capsize– Wheel lock– Stay in lane


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DESCRIPTION OF TESTS

• Test sequence included:– ABS stops on high friction surface– ABS stops on low friction surface– ABS response to low to high friction transition– Peak Braking Coefficient (PBC) using K method

(motorcycle ABS off) on• Low friction surface• High friction surface

– PBC using ASTM method • Low friction surface• High friction surface• Wet high friction surface


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• Pilot tests involved 1 motorcycle (BMW R1200GS), 1 rider

– Preliminary test procedures and results were reviewed by Informal Working Group members

– Preliminary results confirmed suitability of sensors, data acquisition

– Detailed Draft Test Procedure was clarified, revised and circulated prior to Main Tests


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• Main tests included 5 motorcycles, 4 riders• Riders were:

– 2 engineering test riders with previous road racing experience (Riders1 and 4)

– 1 engineering test rider (Rider 2)– 1 experienced club racer and professional race

instructor (Rider 3)


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• Motorcycles– Kawasaki ZZR 1400– Honda VFR800– Suzuki Bandit 1200– Yamaha FZ6– BMW F650 GS

• Surfaces– High friction asphalt, dry– High friction asphalt, wet– Low friction coal-tar-sealed asphalt, wet


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• ABS stops on high and low friction surfaces– Approach the test location at 60 km/h– Apply braking force to front lever and foot pedal

• Hand lever force 200 N ± 40N• Foot pedal force 350 N ± 70N• Analog display (needle type) in view of rider shows

applied forces with respect to the target values

– Hold target brake forces until motorcycle comes to rest

– Stay in the test lane– Process and review measured lever/pedal force

data after several runs in order to determine compliance with the criteria

• Determine if more runs are necessary


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• ABS stops on high and low friction surfaces (cont’d)

– Lever/pedal force criteria • Start time is when brake light is initially illuminated

• “Not later than 0.5 seconds after the activation of the brake lamp, the hand and foot actuation forces shall be

within the specified tolerance.” • “from [0.5 s] after the brake light is activated, to the

moment when the vehicle speed falls below [5 km/h],” the average lever and pedal force shall be within the specified tolerance.


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• ABS response for low to high friction transition– Approach the test area at appropriate speed for a

transition speed of 50 km/h (e.g., approach at 70 km/h)

– Apply braking force to front lever and foot pedal at a marked location (e.g., 10 m before the friction transition)

• Hand lever force 200 N ± 40N• Foot pedal force 350 N ± 70N• Analog display (needle type) in view of rider shows

applied forces with respect to the target values– Hold target brake forces until motorcycle comes to

a stop– Stay in the test lane– Process and review measured lever/pedal force

data and speed at transition in order to determine compliance with the criteria


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• Evaluate peak braking coefficient (PBC) using K method and each test motorcycle– Disable ABS– Run tests on high and low friction surfaces– Rider to follow “Baseline Test Instructions”– K value is the average deceleration in g units

from 40 to 20 km/h– Rider makes multiple runs; the maximum result

across multiple runs is the K value


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BASELINE TEST INSTRUCTIONS

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/


(clarifications are indicated in red bold)

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• Evaluate Peak Braking Coefficient (PBC) using ASTM E1337 “Chirp Test” procedure– DRI Mobile Tire Tester– SRTT tire (E1136)– Test speed 64 km/h (40 mph)– Ramp brake torque until after peak slip is

achieved. Peak torque to be achieved in 0.3 to 0.5 seconds

– Measurement is the average of at least 8 measurements


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METHODS

• Motorcycle measurements– Vehicle speed (radar sensor)– Brake master cylinder pressures, front and rear

• Calibrated to indicate lever and pedal force• In some cases, in addition, used force transducer on

brake pedal in place of rear master cylinder pressure

– Brake caliper pressures, front and rear (at banjo bolt)

– Wheel rotational speed, front and rear– Longitudinal acceleration– Pitch angle, pitch rate– Brake rotor temperature, front and rear– Brake light status– Event marker indicating surface transition

occurrence (for applicable runs)


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METHODS


Yamaha FZ6 front wheel showing caliper pressure sensor, optical speed sensor, and brake temperature thermocouple wires

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METHODS


Suzuki Bandit showing rider display of lever/pedal forces and brake rotor temperatures. Also seen is the radar speed and master cylinder pressure sensors

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METHODS


Example master cylinder pressure sensor

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METHODS


Kawasaki ZZR 1400 showing rider displays, speed sensor, and inertial measurement unit

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METHODS


Kawasaki ZZR1400 showing magnetic pickup speed sensor

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METHODS


Kawasaki ZZR1400 doing an ABS stop on low friction surface

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METHODS

• Example time history data (low friction ABS stop)


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METHODS



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METHODS



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METHODS



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METHODS



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METHODS



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METHODS



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METHODS



Note: Black trace is radar speed data that is uncorrected for pitch angle Red trace is radar speed data that is corrected for pitch angle

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TEST RESULTSTEST RESULTS

RiderNumber ofattempts

Number ofsuccessfulattempts

MFDD measurements(m/s2)

1 2 3

1 13 3 8.98 9.96 9.37

2 16 2 8.95 8.69

3 3 1 9.77

4 15 3 9.52 9.27 10.03


Stops on high friction surfaceKawasaki ZZR 1400

• Successful attempt means that initial speed, brake lever and pedal force meet criteria• Draft performance criteria for high friction surface is for MFDD to exceed 6.17 m/s2

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TEST RESULTS

Rider

Number ofattempts



1 2 3

1 6 2 6.35 5.34

2 15 1 4.73

3 13 3 5.47 5.44 5.36

4 9 1 5.20


Stops on low friction surfaceKawasaki ZZR 1400

• Successful attempt means that initial speed, brake lever and pedal force meet criteria• Draft performance criteria for low friction surface is for MFDD to exceed 2.05 m/s2

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TEST RESULTS




1 2

3

1 4 2 9.11 9.47

2 3 1 8.34

3 4 1 8.61

4 10 3 8.40 9.24 8.95


Stops on high friction surfaceSuzuki Bandit 1200


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TEST RESULTS




1 2

3 4

1 5 4 5.24 5.94 4.98 4.53

2 10 1 4.51

3 16 2 3.28 3.38

4 9 3 3.61 3.92 3.40


Stops on low friction surface Suzuki Bandit 1200


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TEST RESULTS




1 2

3

1 6 3 9.37 9.54 9.54

2 5 2 10.04 9.50

3 7 1 9.06

4 15 2 9.09 8.99


Stops on high friction surfaceHonda VFR 800


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TEST RESULTS

Rider

Number of

attempts

Number ofsuccessfu

lattempts


1 2 3 4 5 6 7

1 3 2 4.71 4.69

2 12 7 4.94 5.39 5.11 4.93 4.94 5.40 5.11

3 4 2 4.70 4.52

4 8 1 5.18


Stops on low friction surfaceHonda VFR 800


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TEST RESULTS


Number ofsuccessfu

lattempts


1 2 3

4

1 2 2 7.85 8.05

2 7 4 7.03 7.63 7.94 7.84

3 3 2 7.39 7.82

4 4 2 8.52 8.18


Stops on high friction surfaceYamaha FZ6


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TEST RESULTS




1 2 3

4

1 3 3 5.33 4.42 4.87

2 5 4 3.97 4.10 5.63 5.14

3 3 1 4.20

4 4 3 4.05 4.46 4.33


Stops on low friction surfaceYamaha FZ6


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TEST RESULTS




1 2

3

1 3 3 9.20 9.59 9.41

2 4 3 9.39 8.99 9.76

3 7 1 8.61

4 7 2 9.59 9.75


Stops on high friction surfaceBMW F650GS


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TEST RESULTS




1

1 3 1 4.80

2 3 1 4.99

3 9 1 4.19

4 9 1 5.18


Stops on low friction surfaceBMW F650GS


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TEST RESULTS

During testing of motorcycle

High friction surface

Low friction surface

Wet high friction surface

Kawasaki ZZR1400 0.90 0.49 0.82

Suzuki Bandit 1200 0.92 0.47 0.89

Honda VFR 800 0.91 0.49 0.84

Yamaha FZ6 0.93 0.47 0.85

BMW F650 GS 0.93 0.49 0.84


Peak Braking Coefficient MeasurementsDRI Mobile Tire Tester (ASTM E1337)

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TEST RESULTS

RiderHigh friction

surfaceLow friction

surface

1 1.04 0.56

2 1.18 0.42

3 1.12 0.56

4 1.14 0.53

ASTM PBC 0.90 0.49


Kawasaki ZZR 1400Peak Braking Coefficient measurements

K method and ASTM method

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TEST RESULTS

RiderHigh friction

surfaceLow friction

surface

1 1.09 0.61

2 1.11 0.58

3 1.14 0.53

4 1.03 0.63

ASTM PBC 0.92 0.47


Suzuki Bandit 1200Peak Braking Coefficient measurements


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TEST RESULTS

RiderHigh friction

surfaceLow friction

surface

1 1.02 0.56

2 1.08 0.52

3 1.02 0.39

4 1.09 0.49

ASTM PBC 0.91 0.49


Honda VFR 800Peak Braking Coefficient measurements


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TEST RESULTS

RiderHigh friction

surfaceLow friction

surface

1 1.08 0.56

2 1.00 0.58

3 1.09 0.43

4 1.02 0.34

ASTM PBC 0.93 0.47


Yamaha FZ6Peak Braking Coefficient measurements


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TEST RESULTS

RiderHigh friction

surfaceLow friction

surface

1 1.06 0.51

2 1.07 0.54

3 0.98 0.50

4 0.85 0.48

ASTM PBC 0.93 0.49


BMW F650GSPeak Braking Coefficient measurements


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TEST RESULTS


Comparison of ABS MFDD measurements (÷9.8 m/s²) and K test measurement for each motorcycle on the high friction surface. Also shown is the corresponding ASTM PBC.

High Friction Surface

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

1.10

1.20

1.30

Kawasaki Suzuki Honda Yamaha BMW

ABS test

K

"ASTM PBC"

• K shown is the average for all riders. Each rider “K” represents that rider’s best run• Error bars show range of measurements for all runs.

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TEST RESULTS


Comparison of ABS MFDD measurements (÷9.8 m/s²) and K test measurement for each motorcycle on the low friction surface. Also shown is the corresponding ASTM PBC

Low Friction Surface

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70


ABS test

K

"ASTM PBC"

• K shown is the average for all riders. Each rider “K” represents that rider’s best run• Error bars show range of measurements for all runs.

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TEST RESULTS


Comparison of ABS “adhesion utilization” measurements based on K and ASTM PBC for each motorcycle on the high friction surface.

High Friction Surface

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40


Based on K

Based on ASTM PBC

• Error bars show range of measurements for all runs.

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TEST RESULTS


Comparison of ABS “adhesion utilization” measurements based on K and ASTM PBC for each motorcycle on the low friction surface.

Low Friction Surface

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40


Based on K

Based on ASTM PBC

• Error bars show range of measurements for all runs.

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TEST RESULTS

Data Reduction• ABS stops on high and low friction surface

– MFDD– Corrected stopping distance

• Non ABS stops on high and low friction surface– “K” Peak Braking Coefficient

• Peak Braking Coefficient measured with DRI Mobile Tire Tester– ASTM E1337

• ABS stops for low to high friction transition– Time delay definition and performance criteria for brake

response is not yet specified


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TEST RESULTS


Example Data Low to High Friction Transition

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TEST RESULTS

Data Reduction• Possible method for evaluation of time delay for low

to high friction transition– T1 when the motorcycle rear axle passes the surface

transition– Identify peak longitudinal acceleration (Ax) for the low

friction interval – T2 is when Ax first exceeds [110%] of the low friction

Ax peak – Time delay is T2 – T1

• Assumption– Low friction interval ends 150 ms before T1, to ensure

that motorcycle front tire has not reached the transition


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TEST RESULTS

RiderNo. of

attempts

No. ofsuccessfulattempts

Time Delay (sec)

1 2

1 9 1 0.05

2 4 2 0.36 -0.03

3 6 2 -0.01 0.28

4 22 1 -0.01


Kawasaki ZZR 1400Low to High Friction Transition

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TEST RESULTS

RiderNo. of

attempts


Time Delay (sec)

1 2

1 5 1 -0.01

2 6 1 0.31

3 18 1 0.10

4 5 2 0.07 0.08


Suzuki Bandit 1200Low to High Friction Transition

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TEST RESULTS

RiderNo. of

attempts


Time Delay (sec)

1

1 4 1 0.12

2 5 1 0.22

3 1 1 0.34

4 5 1 0.38


Honda VFR 800Low to High Friction Transition

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TEST RESULTS

RiderNo. of

attempts


Time Delay (sec)

1 2 3

1 3 3 0.15 0.29 0.26

2 6 2 0.12 0.24

3 6 3 0.22 0.50 0.36

4 5 3 0.38 1.14 0.24


Yamaha FZ6Low to High Friction Transition

•Time delay measurement of 1.14 seconds will be used to demonstrate a possible deficiency in this example data reduction algorithm

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TEST RESULTS

RiderNo. of

attempts


Time Delay (sec)

1 2

1 6 1 -0.01

2 7 2 0.16 0.21

3 3 1 0.19

4 6 2 0.17 0.17


BMW F650 GSLow to High Friction Transition

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TEST RESULTS


Example Data Reduction Not Appropriatefor this Example (Time delay = 1.14 sec)

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OBSERVATIONS

Measurement of K (max friction coefficient) of the test surfaces

• Riders are often able to achieve higher Peak Braking Coefficients (PBC) with the K method than those measured with the ASTM method– On average, motorcycle tires may have higher friction

capability than the ASTM SRTT tire• Substantial variability in K value exists between riders,

motorcycles• More variability occurs on low friction surface than on

high friction surface• Rider ranking may change for different motorcycles,

so one rider does not always give the highest value• Surface PBC depends on the method used to measure

it


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OBSERVATIONS

ABS Stops on High and Low Friction Surface• Riders are generally able to achieve target lever and

pedal average force values without difficulty• Number of runs required to first achieve the target

lever and pedal force criteria may range from 1 to more than 10

• Riders improve with practice• Riders find that ease of task varies with motorcycle• Motorcycles in this study generally meet the proposed

performance criteria in draft GTR– Run-to-run variability may be greater for some

motorcycles than others– Run-to-run variability may be greater on low friction

surface than on high friction surface


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OBSERVATIONS

ABS Stops on Low to High Friction Transition• This was generally the most challenging task for riders• Riders had to:

– Apply specific braking lever and pedal forces at a particular ground location

– Hold specified lever and pedal forces through a large change in longitudinal acceleration

• Riders were generally able to achieve the desired lever and pedal force targets

• Riders were generally able to achieve a target transition speed of 50 ± 5 km/h

• It is possible to have a negative time delay– The zero time is when the motorcycle rear axle passes

over the surface transition. At this point, the front tire has been on the higher friction surface for greater than 100 ms


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OBSERVATIONS

General• Adding pressure sensors to most hydraulic systems was

easily accomplished without any substantial volume or “stiffness” change (in particular by using banjo bolts)

• Substantial variation in motorcycle pitch angle influenced the radar based speed measurement. This was accounted for in data processing

• Analog brake effort indicators were very helpful to riders even though (needle type) display time response was perceptible. A faster display might be of some help to riders

• Brake temperature limits at the start of each run were easily met– This might be more difficult with some combined brake

systems where independent brake application is impossible


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OBSERVATIONS

General• For these motorcycles, disabling of ABS was

accomplished easily• ABS “cycling” is different in frequency, amplitude and

nature for various motorcycles• Amount of ABS “cycling” varies by motorcycle, may

vary run-to-run for same motorcycle• Ideal ABS system may not have perceptible “cycling”


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OBSERVATIONS


• Example high frequency ABS control on front wheel; is this “fully cycling?”

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DISCUSSION

ABS Stops on High and Low Friction Surface• If the rider releases the brake lever because of an

impending pitchover, is this a failure? Of the test procedure criteria? Of the performance criteria?


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DISCUSSION

K method or ASTM measurement of PBC• Measurements with Mobile tire tester generally

behave like samples of a normally distributed population

• The estimate of the population is simply the mean of the samples– More samples will improve confidence in the mean– A minimum number of samples is specified– Random measurement errors tend to be removed when

taking the average value


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DISCUSSION

K or ASTM PBC measurement (cont’d)• For K measurement, the result is the “maximum

value” within the sample set– The samples would not be expected to have a normal

distribution (they are limited at one end)– As the number of samples increases, the maximum value

would be expected to continue to increase– Number of samples to be taken is not specified– Random measurement errors tend to be added to the

result


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DISCUSSION

Surface friction transition runs• GTR draft requires that the vehicle deceleration shall

increase after passing over the transition point– How to define time for deceleration increase to occur– How to define time required for deceleration to

“stabilize” at the higher value


Motorcycle ABS Testing Related to Draft GTR Phase II Results June, 2006 Dynamic Research, Inc. 355...

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Transcript of Motorcycle ABS Testing Related to Draft GTR Phase II Results June, 2006 Dynamic Research, Inc. 355...