Estimation of Influence of ESP on LCV Active Safety in Condition of

Curvilinear Movement

Anton Tumasov, Andrey Vashurin, Eugeny Toropov, Pavel Moshkov and Yury Trusov

Transport Systems Institute, Nizhny Novgorod State Technical University n.a. R.E. Alekseev,

Minin str., 24, 603950 Nizhny Novgorod, The Russian Federation

Keywords: Light Commercial Vehicle, Electronic Stability Control, Electronic Stability Program, Road Test,

Curviline

ar Motion, Line Changing.

Abstract: The article describes the results of road tests of light commercial vehicle equipped by ESP where the

effectiveness of the electronic program estimated in conditions curvilinear manoeuvres: start of the corner

and line changing (in accordance with Russian Standard GOST 31507-2012). The main objective of the

study is the analysis of behaviour of a vehicle equipped with ESP, determination of the moment of ESP

activating as well as the effect of ESP influence on LCV dynamics. The object of study is a metal cargo

LCV with total mass 4500 kg. During the road tests on dry asphalt the vehicle speed and yaw of the

longitudinal and transverse accelerations as well as the steering angle were synchronized registered. The

analysis of experimental data shows that during manoeuvre "start of the corner" the threshold of dynamic

stabilization was found at 58...59 km/h, when in the "line changing" it was about 60...65 km/h, that close to

speeds regulated by GOST binding for all types of LCV (regardless of ESP).

1 INTRODUCTION

One of the main priority directions of Russian

government services and vehicle manufacturers is

the increasing of traffic safety and particularly

vehicles active safety. Light commercial vehicles

(LCV) in Russia constitute a sizeable part of all

vehicles, produced in The Russian Federation (RF).

In this connection, the problems of safety LCV

design and using of intelligent systems are pressing

nowadays.

It is known that every year about 8000000 road

accidents registered in RF. About 30% of them

happened with the commercial vehicles participation

(including LCV). In the case of heavy road accidents

the high percentage of injured and deceased people

could be seen. Using of effective active safety

systems could change this situation for the better.

Intelligent systems, such as electronic stability

control (ESC), could help a driver to keep the

vehicle on the trajectory in various road conditions,

speed of motion and steering manoeuvring.

ESC is well known as various kinds of trade

names (such as ESP), but the main operating

principles of such systems particularly the same.

ESC helps the driver to keep a control over the

vehicle during the extreme manoeuvres. The main

function of ESC is stabilization of the vehicle by

means of trajectory controlling and rollover

prevention. Despite that fact that ESC couldn’t

increase the coefficient of adhesion between the tire

and the road surface, it ensures the driver the

maximum ability of vehicle’s control. ESC systems

are widely used in Europe, USA and others

countries, but in Russia these systems don’t have

such wide application (only foreign vehicles – some

modifications – has ESC, but none of Russian

domestic vehicle has).

In 2008-2009 specialists of Nizhny Novgorod

State Technical University n.a. R.E. Alekseev

(NNSTU) the analysis of road accident with the

participation of commercial vehicles (including

LCV) was made (Groshev and Palkovics, 2010).

The analysis of statistics shows that about 14%

of commercial vehicles drivers before the the crash

made some kind of counter emergency manoeuvres

(Figure 1). The technical state and availability of

vehicle’s equipment play an essential role in such

cases. Particularly, a vehicle, equipped with ESС,

has the best road holding ability at the highest

speeds, in contrast to a similar vehicle without ESС.

118

Tumasov, A., Vashurin, A., Toropov, E., Moshkov, P. and Trusov, Y.

Estimation of Inﬂuence of ESP on LCV Active Safety in Condition of Curvilinear Movement.

In Proceedings of the International Conference on Vehicle Technology and Intelligent Transport Systems (VEHITS 2016), pages 118-123

ISBN: 978-989-758-185-4

Figure 1: The distribution of amount and velocities of

commercial vehicles that took part in mechanical road

accidents.

Analysis results show that ESС can be useful in

more than 30% cases of vehicle manoeuvring at a

speed of 40…60 km/h and in more than 50% cases

of vehicle manoeuvring at a speed of 60…80 km/h.

It was established that installation of ESC

(specifically ESP) system on commercial vehicles

can reduce the number of crash situations, associated

with counter emergency manoeuvres, at least by 8%.

The detailed analysis of severe and extra heavy

road accidents (with injured and deceased people)

shows that commercial transport (including LCV)

takes part in more than 30% of these accidents. It

was found about 20% of severe and extra heavy road

accidents could be avoided or mitigated with the

help of ESC operating (Figure 2). The detailed

analysis of this group of accidents (driveway to the

ditch, rollover, losing control over the vehicle)

shows that in these cases ESC could be really useful

and could be able to come into operation and affect a

road accident outcome.

Figure 2: Supposed efficiency of ESC.

It is interesting to know (Figure 3) that domestic

(produced in Russia) vehicles are more often fall

into road accidents (Nikolskiy, 2010). Meanwhile

more accidents happened on a dry road (more often

than on a wet or snowy road surface – Figure 4).

Presented data allows making a conclusion that a

lot of of severe and extra heavy road accidents with

the participation of commercial vehicles (including

LCV) could be avoided or mitigated with the help of

ESC operating.

Figure 3: The correlation of domestic (Russian) and

foreign commercial vehicles that got into severe and extra

heavy road accidents.

Figure 4: The distribution of severe and extra heavy road

accidents with the participation of commercial vehicles

that happened on roads with different surface condition.

It is worth to underline that since November 1,

2014 all new passenger vehicles weighing up to 3.5

tons and light commercial vehicles sold in the EU

are required to have ESC as standard equipment. In

2015, this requirement extended to other categories

of vehicles. In Russian Federation such kind of

regulation is under the progress and is going to be

obligatory from January 1, 2018. It is also known

that in Russia there is lack of specialists and R&D

laboratories that would be able to produce and set up

ESC systems on vehicles, that is why the domestic

vehicles producers use the services of big-name

corporations (Bosch, Continental, Wabco, Knorr-

Bremse, etc.).

In this case it is interesting to analyze the

behavior of existing vehicle with certified ESC in

condition of different manoeuvres, regulated by

existing Russian Standards, and estimate the

moment of ESC activating as well as the effect of its

influence on vehicle’s dynamics.

2 THE OBJECT OF RESEARCH

The object of the study is a metal cargo LCV

Renault Master 2.3 dci 125 (with total mass 4500

kg) equipped by ESP Bosch 9.0. In this

modification, angular rate sensors, longitudinal and

lateral acceleration sensors are integrated into the

Estimation of Inﬂuence of ESP on LCV Active Safety in Condition of Curvilinear Movement

119

electronic control unit and able to withstand the high

temperature in the engine compartment.

3 DEMANDS OF SAFETY

REGULATION

It was noted above that in Russia there are special

Regulations concerning vehicles steerability and

stability which are mostly similar to requirements,

regulated by Rules of UNECE. At the same time,

Russian Regulations include the requirements,

which do not have analogy among the international

normative documents. The technique of GOST

31507-2012 was taken as a basis for the

experimental studies described below.

The most significant tests from the point of view

of an assessment of active safety properties are:

"start of the corner" and "line changing".

It is possible to allocate the following technical

requirements concerning the over-the-road tests:

– The maximum speed of a vehicle when

performing manoeuvre (further – speed of

manoeuvre Vм) is determined as an

arithmetic average value of speeds of three

test runs with the highest speed without

getting out of road marking limits or any

cornering breakaway.

– The Vм values received at tests should not be

below standard (regulated) Vм values. For

LCV: “start of the corner” V = 60 km/h; “line

changing” V = 70 km/h.

"Start of the corner" test is carried out with the

purpose to define the indicators characterizing

stability of a vehicle in critical modes of movement

on a curvilinear trajectory. On Figure 5 the scheme

of a curvilinear corridor for "start of the corner" test

is shown.

Before entering the corner, a vehicle starts in a

straight motion mode. The highest transmission gear

speed is chosen for ensuring steady functioning of

the engine. At the moment of traversing by the front

wheels of vehicle the border between zone 1 and 2

of the marked corridor the driver quickly removes a

foot from an accelerator pedal and starts turning a

steering wheel to the right for manoeuvre

performance. Position of all other control elements

has to remain constant.

The outside observer (test engineer) notes

cornering breakaway, either getting out of limits of a

marking corridor and informs the driver about it. All

runs are divided into preliminary and control.

Figure 5: Scheme of the road for “start of the corner” test.

All dimensions presented in meters. SS – speed sensors.

Preliminary runs are carried out without

registration of measured parameters for

determination of range of initial speeds for control

runs. Initial speeds of preliminary runs are quite low

– there is no dropping of stability characteristics.

Preliminary runs are finished at a speed when a

vehicle loses its stability.

If cornering breakaway or crossing of the marked

corridor is observing during consecutive three runs

at one speed, all tests are finished.

During tests both: the speed of Vм of a vehicle at

the zone 1 and runs in which there is a cornering

breakaway or a crossing of the marked corridor are

registered. In addition, the angle of rotation of the

steering wheel is registered, allowing define the

maximum angle of rotation of a steering wheel, the

moment of the beginning of manoeuvre, existence of

skid or driver’s mistake. The form of registering

record and value of steering wheel rotation angles let

to judge about the existence of skid in the run. An

average speed of manoeuvres of Vм is the result of

"start of the corner" tests.

On Figure 6 the scheme of a curvilinear corridor

with characteristic sizes for the “line changing” test

is shown. In accordance with Russian regulation, the

"line changing" test is intended to determine the

maximum speed of manoeuvre at changing the line

on a limited track section. Conditions of this test (the

technique) are similar to conditions of the "start of

the corner" test.

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Figure 6: Scheme of the road for “line changing” test. All

dimensions presented in meters. SS – speed sensors.

4 TEST EQUIPMENT

The scheme of test equipment and it’s connection is

shown on Figure 7. The steering angle data was

writing on Kistler Automotive GmbH (steering

angle ± 1250°, error ± 0.1%). The speed of vehicle

recorded by RacelogicVBOX3i 100Hz Data Logger

(absolute error ± 0,1km/ h, the absolute error of

distance measurement ±0,2%). The measurement of

yaw rate as well as longitudinal and lateral

acceleration made by inertial sensor IMU04

Racelogic Ltd. (measuring range: angular velocity of

±450 °/s acceleration ±5g; measurement error: the

angular velocity ±0.014 °/s, acceleration 0,00015g).

The beginning and ending of vehicle movement

fixed by manual trigger timestamp.

Figure 8 shows fragments of LCV tests.

Figure 7: The scheme of test equipment.

Figure 8: LCV road tests: a - “start of the corner”

V = 60 km/; b - “line changing” V = 70 km/h.

5 TEST RESULTS

Graphs of Figure 9 show the results of “start of the

corner” tests. By the character of steering angle and

yaw rate changing it is possible to conclude that a

special function ESP-RMF (rollover suppressing)

was activated. ESP System ESC automatically broke

LCV wheels decreasing the critical lateral

Estimation of Inﬂuence of ESP on LCV Active Safety in Condition of Curvilinear Movement

121

acceleration and the speed of rotation around the

vertical axis, preventing cornering breakaway.

Figure 9: Results of “start of the corner” tests: I – 55 km/h

(ESP was not activated); II – 57,7 km/h (ESP was not

activated); III – 59,2 km/h (ESP was activated); IV – 63

km/h (ESP was activated).

Figure 10: Results of “line changing” tests: I – 60 km/h

(ESP was not activated); II – 65 km/h (ESP was

activated); III – 77 km/h (ESP was activated); IV – 84

km/h (ESP was activated).

Graphs of Figure 10 show the results of “line

changing” tests. In this test (opposed to " start of the

corner ") curves of the angular rotation velocity

(yaw rate) and curves of the steering wheel angle

have similar behavior, thereby driving stability

maintained, LCV continues to move along a path

predetermined by the driver. Threshold ESP during

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“line changing” tests was activated at 60…65 km/ h.

ESP broke LCV wheels, corrected lateral

acceleration thus restoring stability.

This study was conducted in dry weather on dry

pavement as provided in GOST 31507-2012. As it is

shown on Figure 4, more than 25% of severe and

extra heavy road accidents happened on wet and

snowy road surfaces (with a low coefficient of

adhesion). The analysis of dynamics of LCV

equipped by ESP in these conditions could be a

further extension of the performed work.

6 CONCLUSIONS

1. The problem of installation of ESC (specifically

ESP) on commercial vehicles is topical

nowadays in Russia, because commercial

transport takes part in more than 30% of severe

and extra heavy road accidents. Analysis results

show that about 20% of severe and extra heavy

road accidents with the participation of

commercial vehicles (including LCV) could be

avoided or mitigated with the help of ESC

operating. ESC system can be useful in more

than 30% cases of vehicle’s manoeuvring of a

speed of 40…60 km/h and in more than 50%

cases of vehicle’s manoeuvring at a speed of

60…80 km/h.

2. Road tests of light commercial vehicle equipped

by ESP where performed for estimation of the

effectiveness of the electronic program in

conditions curvilinear manoeuvres: start of the

corner and line changing (in accordance with

Russian Standard GOST 31507-2012).

3. The analysis of experimental data shows that

during manoeuvre "start of the corner" the

threshold of dynamic stabilization was found at

58...59 km/h, when in the "line changing" it was

about 60...65 km/h, that close to speeds regulated

by GOST binding for all types of LCV

(regardless of ESP).

4. During “start of the corner” tests a special

function ESP-RMF (rollover suppressing) was

activated by means of braking of LCV wheels,

decreasing the critical lateral acceleration and the

speed of rotation around the vertical axis. During

“line changing” tests ESP broke LCV wheels,

corrected lateral acceleration thus restoring

stability.

5. Further research should be implemented on wet

and snowy road surfaces (with a low coefficient

of adhesion) that will help to analyse the

effectiveness of ESP in different critical

conditions that could happen with a driver.

ACKNOWLEDGEMENTS

This research was done with the financial support of

Ministry of Education and Science of the Russian

Federation in the frame of the complex project “The

establishment of the advanced technology

production of ecological and resources-economy

LCV” under the contract №02.G25.31.006 from

12.02.2013 (Governmental Regulation №218 from

09.04.2010).

The experimental research was conducted with

the use of measurement equipment of the NNSTU

Centre of collective using “Transport Systems”.

REFERENCES

Groshev A., Palkovics L. Application of electronic systems

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http://www.aae-press.ru/j0060/art011.htm.

Nikolskiy V. Prospective Application of Intelligent

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http://www.fisita2010.com/programme/programme/F2

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