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Revision of ECE R41

ASEP Concept for Motorcycles

By Heinz Steven

20.02.2007

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• Check the noise emission behaviour of a motorcycle for driving conditions that occur in real world traffic but are not covered by the ISO 362-2 test(s) (not to exceed concept). This should especially include driving conditions on rural roads.

• The checks should make sure that the noise emission behaviour of the motorcycle under these conditions does not deviate significantly from what one would expect from the ISO 362-2 results.

Aim

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• Vehicle speeds between 20 km/h (v_AA’) and 80 km/h (v_BB’)

• Engine speeds at BB’ up to 0.85*(s – n_idle) + n_idle for pmr <= 66,

• up to 3,4105*pmr-0,3315* (s – n_idle) + n_idle, for pmr > 66

with s – rated engine speed in min-1,

n_idle – idling speed in min-1

pmr = Pn in kW/(m0 in kg +75)*1000

pmr is the power to mass ratio index. This is the rated power of the vehicle (Pn) in kW di-vided by the kerb mass of the vehicle (m0) in kg + 75 (to account for the mass of the driver) and multiplied by 1000.

ASEP test area limitations

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ASEP test area limitations

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

0 50 100 150 200 250 300 350 400 450 500

power to mass ratio index

(n -

n_i

dle)

/(s

- n_

idle

)

n_norm_max

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ASEP test area limitations

0

1000

2000

3000

4000

5000

6000

7000

8000

0 50 100 150 200 250 300 350 400 450 500

power to mass ratio index

(n -

n_i

dle)

/(s

- n_

idle

)

n_max, if n_idle =1000 and s = 8000 min-1

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• The reference point is L_wot_i, the wot test result from ISO 362-2 in gear i and n_PP_i, the corresponding engine speed at PP’.

• For engine speeds within the test area but other than n_PP_i a slope has to be defined in order to take into account that the the noise emission increases with engine speed.

• The slope might be different for engine speeds below and above n_PP_i.

• In addition to that it may be necessary to consider an additional tolerance value of x dB.

Reference Point

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Example for an ASEP limit curve

65

70

75

80

85

0 1000 2000 3000 4000 5000 6000

engine speed in min-1

Lmax

in d

B(A

)

noise emission threshold

reference point, 2988 min-1, 74 dB(A), no extra tolerance

power to mass ratio index = 220, idling speed = 1000 min-1, rated speed = 8000 min-1

Reference point, 3000 min-1, 74 dB(A), (tolerance to be added)

n_max ASEP

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• The data of the ECE R41 test campaign in 2006 do not allow the definition of a complete ASEP test. Additional data has to be collected in order to

define the appropriate ASEP limit curve (slope; tolerance),

identify the appropriate PMR threshold value below which it may be not necessary to apply ASEP tests.

• A test protocol was developed by the R41 task force that defines 3 different driving conditions (vehicle and engine speeds and gear selection) to be used for test campaigns.

Tests to be done

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Thank You

Revision of ECE R41