1. Random Cycle Generator
plan and progress report (kick-off on 14 January 2014)

2. Random Cycle Generator
Random Cycle Generator chassis dynamometer test cycle for common driving behaviour
Cycles for laboratory tests for RDE legislation, i.e., PM/PN emissions
Markov chain approach
Based on previous work for HD test cycles
Covering all driving behaviour, as defined in WLTP database
Limit to physical capabilities of the vehicle

3. Markov chain approach Given the driving behaviour “state”: velocity
Random Cycle Generator
Markov chain approach
Given the driving behaviour “state”:
velocity
e.g., average velocity over past 120 seconds
past acceleration
etc.
change velocity for the next second
based on probabilities for change of current state to the new state
update the state
return to step 1

4. RCG components vehicle information spanning factors WLTP database
Random Cycle Generator
RCG components
vehicle information
spanning factors
for short cycles:
amount of variation
per cycle
this meeting:
RDE-LDV 3 Feb.
WLTP database
probabilities
of driving
behaviour
random
cycle generator
constraints and boundary conditions
data received from
Heinz Steven
29 January
cycle validation
driving cycles
check
testing
(outside project scope)
method validation

5. Input to the random cycle generator
examples:
Input to the random cycle generator
Prated = 82 kW
M = kg
F0 = 153 N
F1 = N/[km/h]
F2 = N/[km/h]2
physical vehicle limitations
based on type-approval data:
test mass
rated power
road-load values
chassis dynamometer restrictions (optional)
avoiding tyre slip, by limiting maximal deceleration
cycle limitations: (optional)
total duration (# seconds)
percentages, and order, of urban/rural/motorway(/ex)
amin > - 2 m/s2
Ncycle = 1800 sec
urban  rural  motorway
urban = 27% [distance]
rural = 31% [distance]

6. Translation of physical vehicle limitations to cycle
Random Cycle Generator
Translation of physical vehicle limitations to cycle
drivability buffer of 10% (WLTP)
power at the wheels, from coast down (WLTP)
general force equation: 0.9*3.6*Prated/v > (M*a + F0 + F1 * v + F2 * v2) “Power capping” at higher velocities: (v > 50 km/h) if P > 0.9*Prated set P at 0.9*Prated If v < 50 km/h, engine speed and gear limit the accelerations: “Acceleration capping” at low velocities, based on power at 50 km/h: a < amax = (0.9*3.6*Prated/50 - (F0 + F1 * 50 + F2 * 2500))/M if a > amax  set a = amax for example: 80 kW, km/h and 1400 kg  amax = 3.45 m/s2 50 a v