ISO/PAS 5101:2021

PUBLICLY ISO/PAS
AVAILABLE 5101
SPECIFICATION
First edition
2021-10
Road vehicles — Field load
specification for brake actuation and
modulation systems
Véhicules routiers — Spécification de la charge pour les systèmes
d'actionnement et de modulation des freins
Reference number
© ISO 2021
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 2
5 Percentiles of field coverage .3
6 Base assumptions and boundary conditions . 4
6.1 General . 4
6.2 Lifetime specifications . 4
6.2.1 Vehicle lifetime . 4
6.2.2 Standstill events, slopes and durations . 5
6.2.3 Standstill duration distribution . 5
6.2.4 Brake duration distribution . 5
6.3 Number of brake operations . 6
6.4 Temperature distributions . 7
6.4.1 Global environmental temperature distribution T . 7
env
6.4.2 Temperature distribution at installation location T . 8
inst
6.4.3 Exceptional high temperatures at the installation location . 9
6.4.4 Function specific occurrence and distributions over temperature ranges . 10
6.5 Brake pedal application profile . 11
6.5.1 Parameters for brake pedal apply and release time . 11
6.5.2 Modulation of deceleration during brake events .12
7 Braking system usage .13
7.1 Base brake function .13
7.2 Dynamic stability functions . 14
7.2.1 Electronic brake force distribution (EBD) . 14
7.2.2 Antilock braking system (ABS) . 14
7.2.3 Traction control (TCS). 16
7.2.4 Electronic stability control (ESC) . 20
7.2.5 Trailer sway control (TSC) . 24
7.2.6 Roll-over mitigation functions . 24
7.3 Brake torque optimizing functions . 25
7.3.1 Brake booster support functions . 25
7.3.2 Hydraulic brake assist (HBA) . 36
7.3.3 Hydraulic rear-brake boost (HRB) . 37
7.3.4 Fading support . 37
7.3.5 Brake preconditioning .38
7.4 Assistance functions .40
7.4.1 Standstill management .40
7.4.2 Hill descent control . 45
7.4.3 Adaptive cruise control (ACC) .46
7.4.4 Parking assist (PA). 51
8 Substitution methods .55
8.1 Dependent functions . 55
8.1.1 Substitution of ABS functions . 55
8.1.2 Substitution of hold functions .56
8.1.3 Substitution of fading support manoeuvres . 57
8.1.4 Substitution of brake disc wiping manoeuvres . 57
8.1.5 Substitution of base brake functions .58
Bibliography .59
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,
Vehicle dynamics and chassis components.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Vehicle development programs tend to grow in complexity and integration of the braking system with
chassis dynamics and mechatronics, demanding more robust and comprehensive evaluation programs.
Also, to remain competitive, braking systems and their components’ functionality and application
across multiple vehicle architectures and platforms are increased.
The proper selection and adaptation of field load spectra and profiles to the specific program ensure
functionality, reliability and braking system availability. This document defines a library of field
load schedules to help developing simulation and testing programs tailored to the vehicle or system
specification and requirements. Specific cycles and load collectives including the main functions
associated with everyday driving and operation and exceptional load cases are described to ensure safe
braking behaviour. This document's field load was typically derived from analysing field data collected
from almost 1 million vehicles having driven more than 45 billion km. Several vehicle and brake system
suppliers from vehicles used in different regions worldwide contributed to this field data collection. In
addition, data from driving studies with specific measurement equipment was used. Wherever the data
available from field or studies was not sufficient, existing specifications or expert judgement served to
derive conservative assumptions.
This document provides field loads independent of the vehicle technology, vehicle specification,
intended use and field usage. It remains the manufacturer's responsibility to include and adapt the field
loads to the specific vehicle configuration. The adaptation includes at least:
— define sampling and testing plans, including vehicle configuration(s), road conditions selection of
the specific profiles and load spectra of this document;
— define level of evaluation and integration of simulation, Hardware-in-the-Loop, physical testing
methods, along with other components and software functions part of the testing program;
— agree on performance and reliability criteria (including statistical tools and metrics);
— reflect specific system architectures and control technologies for the unit(s) under testing.
v
PUBLICLY AVAILABLE SPECIFICATION ISO/PAS 5101:2021(E)
Road vehicles — Field load specification for brake
actuation and modulation systems
1 Scope
This document specifies expected field loads for functions provided by the braking system actuator and
modulator and applies to passenger cars and light commercial vehicles (classes M1 and N1, according
to UNECE).
Functions addressed in this document are:
— dynamic stability functions (e.g. electronic stability control);
— brake torque optimizing functions (e.g. electronic brake force distribution);
— brake assistance functions (e.g. hill start assist).
This document only covers functions where data of appropriate maturity are available. There are
additional functions of a braking system, which are not covered by this document.
By describing the expected field loads, this document specifies representative manoeuvres and
occurrences for different functions. These serve as an orientation for the derivation of test procedures.
This document applies to vehicles up to conditional automation (SAE J 3016 level 3) with a maximum of
30 % automated brake operations.
NOTE Field loads for automation levels above level 3 are under consideration for future editions.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
brake booster
part of the actuation unit, excluding master cylinder, in systems with separate actuator and modulator
Note 1 to entry: A brake booster is not part of braking systems with integrated actuator and modulator (see
Figure 1).
3.2
fading
decrease of braking torque as a function of temperature or vehicle speed at constant application force
Note 1 to entry: Amongst others, the decrease of the friction by the temperature is the most important effect.
[SOURCE: ISO 611:2003, 7.1.7, modified — The original term was "brake fade", the word “vehicle” and
Note 1 to entry were added, and the examples were removed.]
3.3
brake friction coefficient
ratio between the tangential force and the normal force, acting between linings and drum or disc
[SOURCE: ISO 611:2003, 9.19.1, modified — The symbols and formula were removed, the original term
was "coefficient of friction".]
3.4
coefficient of adhesion
µ
ratio between the tangential force transmitted to the road by a tyre and the normal force
[SOURCE: ISO 611:2003, 9.19.2, modified — "k" was changed to "µ", the symbols, formula and note were
removed.]
3.5
control time
duration the braking system is controlling the pressure
3.6
fully active brake operation
deceleration intended by the driver and automatically initiated and operated by the braking system
3.7
nominal runout pressure
lowest master cylinder pressure where maximum support from the actuator is reached in quasi-static
operation
Note 1 to entry: Only applies to separated actuator and modulator.
Note 2 to entry: For vacuum-based actuation systems, the nominal runout pressure refers to sea level.
Note 3 to entry: Above this pressure, only the unsupported pressure increase is possible.
3.8
partially active brake operation
deceleration initiated by the driver and supported by the modulation of the wheel brake pressure
3.9
standstill
stopping situation during a trip in which the vehicle is not moving
EXAMPLE Stopping at traffic lights or in heavy traffic situations.
Note 1 to entry: Standstill does not include parking situations.
3.10
steering angle
mean value of angle of left and right front wheel relative to the longitudinal axis of the vehicle
Note 1 to entry: Rear-wheel steering is not considered in this document.
4 General
This document describes use cases represented by manoeuvres and their occurrences for various
functions of the braking system to describe the expected field loads for a braking system. Unless
otherwise specified, these manoeuvres and occurrences are derived from empirical values and
collected field data.
The manoeuvres and occurrences described in this document serve as an orientation to develop test
procedures. The applicability of the generalized field loads detailed in this document needs to consider
the specific braking system and vehicle configuration.
Figure 1 depicts the components of the braking system addressed in this document.
Figure 1 — Components of the braking system
5 Percentiles of field coverage
The braking system supports multiple vehicle dynamics functions. The probability of high usage of all
functions in an individual vehicle is much lower than the probability of high usage of only one single
th
function in an individual vehicle. A specification aiming to cover the 100 percentile vehicle for every
individual function would lead to an over-specification.
The field load for electronic brake force distribution (EBD), antilock braking system (ABS) and adaptive
th
cruise control (ACC) aims to describe the 99 percentile vehicle usage. All other functions described
th
in Clause 7 cover the 95 percentile vehicle usage for each function. However, it is unlikely that all
functions – given the multitude of functions - are used up to the specification limit in one individual
vehicle. This approach leads to a field coverage significantly above 99 %.
th
NOTE 1 ABS, EBD and the standard brake function are specified to cover the 99 percentile vehicle usage
because products only providing this set of functions exist and therefore, the combination effect is weak. ACC is
th
specified to cover the 99 percentile because it is an automation of the standard braking function.
Figure 2 illustrates an example of the usage of an individual function.
Key
X load or stress level with consistent engineering units
Y probability density
a th
99 percentile.
Figure 2 — Schematic example of the probability density function P for the load σ
NOTE 2 Few vehicles experience a very low load; few vehicles experience a very high load; most vehicles
experience a medium level of load.
NOTE 3 Typically, braking system components can endure loads above their specification. Furthermore, the
load a component experiences is typically lower than the load described.
6 Base assumptions and boundary conditions
6.1 General
This clause defines the assumptions for the vehicle lifetime and braking system lifetime. These
assumptions serve as the baseline for the manoeuvres and occurrences of the functions described in
Clause 7.
NOTE Clause 7 describes the field load for braking system functions but not for wearing parts such as brake
pads and brake discs.
6.2 Lifetime specifications
6.2.1 Vehicle lifetime
The field loads described in this document correspond to a vehicle lifetime of either 300 000 km or
8 000 h ignition-on time or 15 years, whichever occurs first.
The expected amount of trips is up to 50 000 over a vehicle lifetime.
6.2.2 Standstill events, slopes and durations
The expected amount of brake operations that lead to a standstill is 480 000 over a vehicle lifetime.
Table 1 shows the distribution of slopes at the standstill events. The values shown include uphill and
th
downhill slopes and cover the 99 percentile. An even distribution between up- and downhill situations
is assumed.
Table 1 — Distribution of standstill events versus slope angle
Slope at a standstill Probability
[%] [%]
> 30 - 50 0,006
> 20 - 30 0,194
> 15 - 20 0,8
> 10 - 15 2
> 5 - 10 9
≤ 5 88
6.2.3 Standstill duration distribution
In total 480 000 standstill events are defined over vehicle lifetime. Table 2 shows the distribution of
their duration. The durations are independent of any active function when the vehicle ignition is on.
th
The distribution covers the 99 percentile usage.
NOTE The parking times between two trips are not considered.
Table 2 — Distribution of standstill duration
Standstill duration Frequency
[s]
0 - 2 126 000
2 - 10 162 000
10 - 30 100 000
30 - 60 47 000
60 - 180 34 000
180 - 900 9 000
> 900 2 000
Sum 480 000
6.2.4 Brake duration distribution
Table 3 shows values of the brake duration distribution of an average driver.
Table 3 — Distribution of brake duration
Brake duration Percentage per class
[s] [%]
0 – 2 57
2 – 5 25
5 - 10 9
10 - 60 8
> 60 1
Sum 100
6.3 Number of brake operations
th
Over a vehicle lifetime, the 99 percentile of brake operations corresponds to 2,2 million brake
operations. Of these 2,2 million brake operations, 600 000 events take place during standstill.
The frequency of brake operations during standstill represents brake operations that begin and end
during vehicle standstill.
Table 4 shows the number of brake operations in deceleration classes of 0,05 g.
The frequencies shown in Table 4 include the base brake function and all functions intended to
decelerate or hold the vehicle.
This document assumes 10 000 kPa is equivalent to 1,0 g for a typically laden vehicle.
Table 4 — Distribution of brake operations versus deceleration and brake pedal force
Deceleration Brake pedal Frequency per class Frequency per class Frequency per class
a
[g] force while driving during standstill
[N]
0,00 ≤ x ≤ 0,05 20 205 033 84 569 289 602
0,05 < x ≤ 0,10 20 639 927 243 706 883 633
0,10 < x ≤ 0,15 29 404 300 115 070 519 370
0,15 < x ≤ 0,20 38 200 177 56 182 256 359
0,20 < x ≤ 0,25 48 84 266 25 350 109 616
0,25 < x ≤ 0,30 57 35 147 16 912 52 059
0,30 < x ≤ 0,35 67 14 463 12 771 27 234
0,35 < x ≤,0,40 77 7 168 9 810 16 978
0,40 < x ≤ 0,45 86 3 893 7 793 11 686
0,45 < x ≤ 0,50 96 2 144 5 892 8 036
0,50 < x ≤ 0,55 105 1 252 4 585 5 837
0,55 < x ≤ 0,60 115 745 3 474 4 219
0,60 < x ≤ 0,65 124 466 2 718 3 184
0,65 < x ≤ 0,70 134 332 2 218 2 550
0,70 < x ≤ 0,75 143 198 1 613 1 811
0,75 < x ≤ 0,80 153 91 1 067 1 158
0,80 < x ≤ 0,85 163 77 995 1 072
0,85 < x ≤ 0,90 172 63 917 980
0,90 < x ≤ 0,95 182 52 831 883
0,95 < x ≤ 1,00 191 41 739 780
1,00 < x ≤ 1,05 201 32 640 672
1,05 < x ≤ 1,10 210 25 534 559
1,10 < x ≤ 1,15 220 19 421 440
1,15 < x ≤ 1,20 230 14 301 315
1,20 < x ≤ 1,25 239 10 175 185
1,25 < x ≤ 1,30 249 9 105 114
> 1,30 > 250 56 612 668
1 600 000 600 000 2 200 000
a
Including brake operations leading to a vehicle standstill.
NOTE 1 Table 4 shows data over a vehicle lifetime according to 6.2.1.
NOTE 2 Brake pedal forces are derived from the deceleration to brake pedal force characteristic of vehicles
which delivered the corresponding field data.
NOTE 3 Brake pedal forces values are used for brake pedal applies during standstill, deceleration values for
brake pedal applies during driving.
NOTE 4 For vehicle configurations differing from those assumptions, the relation between brake pressure
and deceleration is determined individually.
Figure 3 illustrates the corresponding cumulative distributions from Table 4.
Key
X cumulative number of load cycles in counts
g deceleration level in g
1 total cumulative brake operations
2 cumulative brake operations while driving
3 cumulative brake operations during standstill
Figure 3 — Cumulative distribution per class
6.4 Temperature distributions
6.4.1 Global environmental temperature distribution T
env
The distribution of the environmental temperatures, as shown in Table 5, uses the following principles:
— global coverage of typical, low and high-temperature profiles;
— weighting according to human population density, cities with less than 1 000 inhabitants are not
considered;
— extreme temperature events, which do not occur regularly within 10 years, are not covered.
Table 5 — Distribution of environmental temperature
T Probability
env
[°C] [%]
‒ 40 0,5
‒ 30 2
‒ 20 5
‒ 10 5
0 7,5
10 15
20 25
30 25
40 14
50 1
Sum 100
6.4.2 Temperature distribution at installation location T
inst
Table 6 provides the estimated probability distribution as a function of the temperature at the
installation location T .
inst
The temperature at installation location T reflects the superposition of the environmental
inst
temperature T outside the vehicle with the temperature increase dT at the installation location in a
env
combustion engine compartment during vehicle operation.
The dT in electric vehicles is lower and therefore is assumed to be covered by this specification. Use
Formula (1) to determine the temperature distribution at the installation location.
T = T + ΔT (1)
inst env
where
T is the temperature at the installation location of the brake actuation and modulation sys-
inst
tems;
T is the distribution of worldwide environmental temperature outside the vehicle (vehicle
env
independent, see 6.4.1);
ΔT is the temperature increase by vehicle usage at installation location (vehicle dependent,
typical vehicle resulting distribution for T given in Clause 6).
At environmental temperatures of -40 °C, no increase of T by vehicle usage is assumed due to the
inst
airflow's high cooling capability.
Moderate and high environmental temperatures lead to a ΔT of up to 55 K.
Specific temperature effects may be considered when the brake system components directly interact
(have thermal conductivity) through a mechanical connection.
EXAMPLE Direct cooling effect by the connection of an actuator to the passenger compartment.
Table 6 — Distribution of temperature at the installation location
T Probability
inst
[°C] [%]
‒ 40 0,5
‒ 20 2,5
20 28
60 40
80 26
105 3
Sum 100
6.4.3 Exceptional high temperatures at the installation location
Higher ΔT can occur as a combination of exceptional events and devices' proximity with significantly
increased temperatures.
EXAMPLE Stopover after long steep uphill driving at low speed with fully laden trailer and vehicle.
NOTE 1 This occurs only in rare vehicle configurations.
To also cover such exceptional situations, Figure 4 shows representative manoeuvres, including 120 °C.
Phase 1 defines the starting condition. The braking system is heated thoroughly until 105 °C to ensure
all system components start with this initial temperature.
Phase 2 represents the heat-up phase. During this time, with a minimum of 300 s, T shall increase to
inst
120 °C with a constant temperature gradient.
Phase 3 represents the application and cool-down phase. During this time frame of at least 600 s,
apply 10 actuations at 0,15 g and 10 actuations at 0,35 g deceleration requests. These actuations are
applied by input from the brake pedal or as a fully automatic brake operation, whichever mode induces
the system's higher load. The pressure cycle shall follow the ACC-16 and ACC-35 profiles. Distribute
the brake applications, including the corresponding pause times, evenly over time. The installation
temperature of the braking system shall decrease to 105 °C with a constant temperature gradient.
Repeat this procedure a total of 15 times to simulate one occurrence of this situation once every year
over a vehicle lifetime.
Due to the rare occurrence, any combination with other conservative assumptions (e.g. extreme
frequency of use) is not expected.
Key
T temperature at the installation location in °C
inst
t elapsed time [s]
1 conditions for start
2 heat-up phase
3 application and cool-down phase
Figure 4 — Representative manoeuvre for extreme temperatures at the installation location
NOTE 2 The temperature gradients in phase 2 and phase 3 allow the braking system to reach the temperature
it is expected to be subjected to in its installation location.
6.4.4 Function specific occurrence and distributions over temperature ranges
Table 7 shows neglectable occurrences of T /manoeuvre combinations as indicated by "-". Expected
inst
occurrences of T /manoeuvre combinations are indicated by "x". Table 7 only lists manoeuvres that
inst
typically would not occur at all indicated temperature ranges.
The total required number of specified events for a function should not be reduced.
NOTE The manoeuvres shown in Table 7 are described in Clause 7.
Table 7 — T dependent occurrence of manoeuvres
inst
Function Manoeuvre T < –20 °C –20 °C ≤ T ≤ 80 °C T > 80 °C
inst inst inst
Cold Start Cold Start 1 x x -
Cold Start 2 x x -
ABS ABS 1 x x -
ABS 4 x x -
ABS 5 L x x -
ABS 5 R x x -
ABS 7 x x -
Table 7 (continued)
Function Manoeuvre T < –20 °C –20 °C ≤ T ≤ 80 °C T > 80 °C
inst inst inst
HRB HRB 1 - x x
HRB 2 - x x
Fading Fading 1 - x x
Fading 2 - x x
TCS ORD TCS ORD 1a - x x
TCS ORD 1b - x x
TCS ORD 2a - x x
TCS ORD 2b - x x
TCS ORD 3a - x x
TCS ORD 3b - x x
BDW BDW - x x
Manoeuvres with a calculated occurrence of less than one activation in a temperature class can be
omitted. Manoeuvres with an occurrence of fewer than 10 activations in a temperature class can be
carried out by load equivalent manoeuvres at the same temperature. The loss of accuracy is negligible.
6.5 Brake pedal application profile
6.5.1 Parameters for brake pedal apply and release time
6.5.1.1 General
A typical apply and release time of 650 ms is assumed independent of the brake event's target pressure.
The typical application time is from the onset of brake pedal application until pressure reaches 90 % of
the first local maxima (t ). The typical release time is from the time pressure reduces to 90 % of the
a-90
last local maxima until the pressure is fully released (t ), see Figure 5.
r-90
Key
t time
p brake pressure during brake pedal apply
a
p brake pressure during brake pedal release
r
t time from p until p is reached
a-90 a-0 a-90
t time from p until p
r-90 r-90 r-0
a
Target brake pressure of brake pedal apply.
b
Brake pressure level at beginning of brake pedal release.
NOTE The profile illustrates a typical manoeuvre, but not the actual gradient during the apply and releases
times, nor results from field data. During the onset of the application or during the end of the release time,
the gradient can be nonlinear due to the actual driver demand, system sizing, and the system response at low
pressure.
Figure 5 — Example for interpretation of apply and release times
When defining representative pressure profiles for the brake systems function, manufacturers should
consider the typical apply and release times. According to the manufacturer's specific trigger logic,
apply the applicable gradients (rate of change) for functions intended to support the driver during panic
braking or emergencies.
6.5.1.2 Background
The analysis represents field data from more than 570 000 brake events to define typical apply and
release times. The analysis discarded events identified as panic actions before averaging the apply and
release times.
6.5.2 Modulation of deceleration during brake events
6.5.2.1 General
Modulation of deceleration during a brake event represents expected driver behaviour. Analysis of
field data indicates one modulation event per brake event on average. The average modulated volume
is 30 % of the volume at the maximum pressure of each event. The field data also indicates that most
modulation events occur at the end of a brake event and low deceleration.
A suitable representation of this modulation can be implemented by adding a 0,05 g modulation on
every brake release step, as shown in Figure 6.
Key
a
Max.
Figure 6 — Example of brake event with modulated brake pedal release
6.5.2.2 Background
Field data representing 660 000 brake events was analysed. Modulation of deceleration is more
frequent during brake events leading to a standstill than during brake events not leading to a standstill.
The driver tends to avoid the stopping jerk by partly releasing the brake pedal and – when a standstill is
achieved – pushing the brake pedal again to ensure a safe standstill. Brake events leading to standstill
commonly include multiple modulations. On the other hand, a significant fraction of brake events not
leading to a standstill does not show any modulation. One modulation per action is the average for
events leading to a standstill and not leading to a standstill.
7 Braking system usage
7.1 Base brake function
The load of the base brake function highly depends on the specific braking system configuration.
Therefore, generic manoeuvres cannot be given. Relevant manoeuvres and frequencies can be
determined based on the lifetime specifications (see 6.2) and the brake pedal application profile (see
6.5).
7.2 Dynamic stability functions
7.2.1 Electronic brake force distribution (EBD)
EBD is dependent on a variety of vehicle-specific characteristics and software parameters. Therefore,
a generic number or calculation rule cannot be given here. Instead, the following procedure is
recommended to gather the missing information regarding the EBD activation frequency:
Evaluate the minimum deceleration at which the EBD intervention occurs for the typically laden vehicle
on a surface with dry asphalt (µ ~ 1). Determine the deceleration using vehicle test or simulation.
Determine the frequency of brake operations equal or higher to this deceleration using Table 4, column
frequency per class while driving. Use this number as the number for vehicle-specific EBD activations
over a lifetime.
NOTE Based on experience, 50 % of the EBD cycles occur as pressure hold at the rear axle, the other 50 % as
brake pressure release at the rear axle followed by a pressure increase.
7.2.2 Antilock braking system (ABS)
7.2.2.1 Description of function
ABS prevents the wheels from locking and supports the stability and steerability of the vehicle.
7.2.2.2 Manoeuvre description and expected occurrence
Table 8 describes the expected occurrence and manoeuvre parameters for the function of ABS.
Table 8 — Overview of manoeuvres for ABS
Brake
p Speed Control time
MC
Name Frequency µ pedal Use case
[kPa] [km/h] [s]
force [N]
road disturbances,
ABS 1 10 300 0,20 3 000 75 50 1
snow, ice
ABS 2 1 950 0,35 6 000 150 50 1 snow, gravel
ABS 3 500 0,2 – 1,4 10 000 250 70 2 rough road
ABS 4 50 1/0,2/1 13 000 500 100 4 double µ-jump
ABS 5a 25 0,8/0,15 13 000 500 80 4 µ-split
ABS 5b 25 0,15/0,8 13 000 500 80 4 µ-split
emergency stop on
ABS 6 200 1,00 18 000 1 200 80 2
high-µ
emergency stop on
ABS 7 50 0,20 22 000 1 800 70 4
low µ
Total 13 100
NOTE 1 The total control time of the manoeuvres sums up to 3,96 h.
For modulation systems, use master cylinder pressure (p ) as the manoeuvre parameter.
MC
The values of the brake pedal force characteristics are derived from the p , applying the characteristic
MC
from a passenger car.
The manoeuvre parameter brake pedal force shall be used for actuation and integrated brake systems
instead of p .
MC
NOTE 2 The high-pressure events cover 99 % of field data from different vehicle types (passenger cars, vans
and light commercial vehicles with pressure to brake pedal force characteristics corresponding to 27 500 kPa at
1 800 N).
The wheel brake pressure modulation shall be according to the control strategy of the brake system
considered.
As illustrated in Table 9 for the ABS 3 manoeuvre, the front right wheel experiences the same adhesion
level as the front left wheel, plus an offset of 150 ms. The rear wheels experience the same adhesion
levels as the corresponding front wheels with a 300 ms offset.
Table 9 — Pattern of the coefficient of adhesion level for the ABS 3 manoeuvre for all four
wheels
Front left wheel Front right wheel Rear left wheel Rear right wheel
Time Time Time Time
µ µ µ µ
[s] [s] [s] [s]
0,00 0,8 0,00 0,8 0,00 0,8 0,00 0,8
0,10 0,6 0,25 0,6 0,40 0,6 0,55 0,6
0,20 1,0 0,35 1,0 0,50 1,0 0,65 1,0
0,30 0,8 0,45 0,8 0,60 0,8 0,75 0,8
0,40 0,8 0,55 0,8 0,70 0,8 0,85 0,8
0,50 0,2 0,65 0,2 0,80 0,2 0,95 0,2
0,60 1,4 0,75 1,4 0,90 1,4 1,05 1,4
0,70 0,8 0,85 0,8 1,00 0,8 1,15 0,8
0,80 0,8 0,95 0,8 1,10 0,8 1,25 0,8
0,90 1,0 1,05 1,0 1,20 1,0 1,35 1,0
1,00 0,4 1,15 0,4 1,30 0,4 1,45 0,4
1,10 1,2 1,25 1,2 1,40 1,2 1,55 1,2
1,20 0,7 1,35 0,7 1,50 0,7 1,65 0,7
1,30 0,8 1,45 0,8 1,60 0,8 1,75 0,8
1,40 0,8 1,55 0,8 1,70 0,8 1,85 0,8
1,50 0,9 1,65 0,9 1,80 0,9 1,95 0,9
1,60 0,6 1,75 0,6 1,90 0,6 2,05 0,6
1,70 1,0 1,85 1,0 2,00 1,0 2,15 1,0
1,80 0,8 1,95 0,8 2,10 0,8 2,25 0,8
1,90 0,8 2,05 0,8 2,20 0,8 2,35 0,8
2,00 0,7 2,15 0,7 2,30 0,7 2,45 0,7
2,20 0,8 2,35 0,8 2,50 0,8 2,65 0,8
2,65 0,8 2,65 0,8 2,65 0,8 2,65 0,8
The manoeuvre ABS 4 describes sudden changes in coefficients of adhesion to represent changing road
surfaces. These changes in coefficients of adhesion are detailed in Figure 7.
Key
µ coefficient of adhesion
d distance in metres
v target speed at end of manoeuvre ABS 4
target
Figure 7 — Pattern of the µ-level for the ABS 4 manoeuvre
The manoeuvre ABS 5 relates to different coefficients of adhesion (0,8 and 0,15) at the wheels on the
left-hand side and right-hand side of the vehicle.
7.2.2.3 Rationale and additional information
During rough road driving, the coefficient of adhesion and the normal force vary over time. The
manoeuvre ABS 3 only varies the coefficient of adhesion as a combination of both effects.
Other functions can also trigger ABS-cycling; see Clause 8 for corresponding substitution methods.
7.2.3 Traction control (TCS)
7.2.3.1 Description of function
The traction control function modulates the pressure of the individual wheel brakes to avoid slipping of
wheels when accelerating on surfaces with a low coefficient of adhesion.
7.2.3.2 Manoeuvre description and expected occurrence
This document defines five types of manoeuvres to represent the load of the traction control
functionality. Table 10 describes these manoeuvres and their expected occurrence.
NOTE 1 For this function, driving situations are specified instead of pressure versus time because these
depend, for example, on control strategy, vehicle characteristics and parametrization of the function.
Table 10 — Manoeuvre definition and frequency
Accelerator pedal
Road surface Control time for each
position (driver v - v
Driving ma- min max
left/right drive-off
Frequency
request)
noeuvre
[km/h]
µ-split [s]
[%]
TCS 1a 0,2/0,9 40 2 – 5 9 000 approximately 1,5
TCS 1b 0,9/0,2 40 2 – 5 9 000 approximately 1,5
TCS 2a 0,25/0,35 45 2 – 22 5 050 approximately 3,0
TCS 2b 0,35/0,25 45 2 – 22 5 050 approximately 3,0
TCS 3a 0,2/0,9 60 2 – 15 1 000 approximately 2,7
Table 10 (continued)
Accelerator pedal
Road surface Control time for each
position (driver v - v
Driving ma- min max
left/right drive-off
Frequency
request)
noeuvre
[km/h]
µ-split [s]
[%]
TCS 3b 0,9/0,2 60 2 – 15 1 000 approximately 2,7
TCS 4a 0,2/0,9 100 2 – 70 100 approximately 10,0
TCS 4b 0,9/0,2 100 2 – 70 100 approximately 10,0
TCS 5a 0,2/0,9 100 2 – 40 50 approximately 6,0
TCS 5b 0,9/0,2 100 2 - 40 50 approximately 6,0
Total 30 400
NOTE 2 The total control time of the manoeuvres sums up to 18,14 h.
NOTE 3 Symmetrical interventions can often be avoided by engine torque reductions. The residual
symmetrical interventions are covered by left/right manoeuvres.
All manoeuvres describe different coefficients of adhesion at the wheels on the left-hand side and right-
hand side of the vehicle.
Manoeuvre 5 is performed with a brake friction coefficient reduced by 30 % to simulate fading
conditions.
NOTE 4 The manoeuvre definitions do not explicitly specify a road slope; the engine torque values cover road
slopes.
7.2.3.3 Rationale and additional information
The five manoeuvres cover different road surface conditions such as low-µ on both sides of the vehicle
(manoeuvre 2) and different µ-levels on either side of the vehicle (µ-split). Manoeuvres with µ-split are
intended to be carried out symmetrically, i.e. with low-µ on the left side of the vehicle in 50 % of all
cases and low-µ on the right side of the vehicle in 50 % of all cases.
NOTE This clause covers front wheel drive, rear wheel drive and all-wheel drive.
7.2.3.4 Traction control for off-road (TCS ORD)
7.2.3.4.1 Description of function
Some vehicles are used off-road beyond the realm of standard traction control. More and stronger TCS
activations are expected in heavier terrain because the surface can consist of many bumps and holes.
This document considers regular passenger cars, light commercial vehicle and sport utility vehicles.
7.2.3.4.2 Manoeuvre description and expected occurrence
...