THE STEERING SYSTEMMORE THAN JUST COMPONENTS

SOLUTIONS & INNOVATIONS FOR COMMERCIAL VEHICLES

ASIL D

Safety Steering

Computer

Axle Integrated

Safety Angle

Transducer

Each vehicle is different, even if there are only small differences

in vehicle geometry. Our EHLA® steering systems are sufficiently

flexible for this. They can be adjusted via parameters to different

geometries.

When designing your auxiliary steering system we

rely on established standard components which

have already been used in mass production.

REGARDLESS WHETHER MASS PRODUCTION OR A SINGLE VEHICLE, WE ARE THE RIGHT PARTNERS FOR YOU!

GLOBAL MARKET LEADER FOR ELECTRO­HYDRAULIC AUXILIARY STEERING SYSTEMS EHLA®

ELECTRICALLY POWERED HYDRAULIC POWER PACK

ENERGY-SAVINGThe motor is only supplied with power during active steering.

When driving straight ahead for a long time almost no energy is

consumed. The fuel saving is around 0.5 l/100 km. This energy-

saving concept is also ideal for electric and hybrid vehicles.

INDEPENDENCEThe steering system is completely independent of the vehicle‘s

engine with the hydraulic power pack, since no mechanical power

take-off (PTO) is required. That is why the auxiliary steering sys-

tem can be installed in almost every vehicle, regardless of the

manufacturer.

POWERFULThe Hydraulic Power Pack indeed does justice to its name. An axle

loaded with 12 metric tons can be steered in standstill from the left

stop to the right stop in less than four seconds.

INTELLIGENTThe Hydraulic Power Pack communicates via CAN bus with the

safety steering computer. Thus the direction of rotation of the en-

gine, the speed and the engine status of the Hydraulic Power

Pack and with it the movement of the auxiliary steering axle are

monitored and controlled.

EASY INSTALLATION AND ADAPTIONThanks to the integrated hydraulic block the Hydraulic Power

Pack is directly connected to the steering cylinder which means

less piping and less installation time. Furthermore less cable is

required since no proportional valves have to be actuated. The

Hydraulic Power Pack can be installed where space is available.

HIGH SAFETY LEVELAlso with the Hydraulic Power Pack important functions of the

auxiliary steering system can be realised with safety level ASIL D.

PLUG-AND-PLAY (OPTIONAL)Optionally you can get a completely wired stainless steel box, in

which a safety steering computer, the hydraulic tank and the

Hydraulic Power Pack are already installed. The connectors and

hydraulic connections are located at the outside, so that a real

plug and play solution is available.

Hydraulic

Power Pack

ASIL DNEW

Safety Angle

Transducer

Safety Steering

Computer

Axle Integrated

Safety Angle

Transducer

EXAMPLES OF STEERING MODES

GLOBAL MARKET LEADER FOR ELECTRO HYDRAULIC AUXILIARY STEERING SYSTEMS EHLA®

left right menu

manual

1

2 3 4 5

6

EHU – Electronic rear swing-out suppression

ON ROAD

Steering mode All-wheel steering

Steering mode Crab steering

Steering mode Manual e.g. via T-handle

Steering mode Manual via buttons

1

2

3

4

5

6

We offer a big variety of different EHLA® auxiliary steering systems. The number of axles does not matter at all.

When driving through narrow passages the swing-out of the

vehicle‘s rear is suppressed by shifting the steering line.

The self-tracking pusher axle or tag axle is often equipped with

lifting function and pneumatic suspension. In order not to exceed

the permissible axle loads of the rigid axles, the lift axle is used

to accommodate additional axle loads. Our automatic axle load

distribution system can be used here.

This option is particularly interesting if the vehicle chassis is ex-

tended by a lifted pusher axle or tag axle.

AUTOMATIC REAR SWING-OUT SUPPRESSION

AUTOMATIC AXLE LOAD DISTRIBUTION

SOME FEATURESMAXIMUM MANOEUVRABILITY AND HIGH DRIVING STABILITY ARE BY NO MEANS CONTRADICTORY

The steering system is designed as dynamically as you need it.

Maximum manoeuvrability is required for slow speeds and large

steering angles are possible. For higher speeds the steering

angle is reduced to guarantee high directional stability. These

values can be set by parameters.

THE RIGHT EHLA® SYSTEM FOR EACH VEHICLE

ELECTRICALLY POWERED HYDRAULIC POWER PACK

ENERGY-SAVINGThe motor is only supplied with power during active steering.

When driving straight ahead for a long time almost no energy is

consumed. The fuel saving is around 0.5 l/100 km. This energy-

saving concept is also ideal for electric and hybrid vehicles.

INDEPENDENCEThe steering system is completely independent of the vehicle‘s

engine with the hydraulic power pack, since no mechanical power

take-off (PTO) is required. That is why the auxiliary steering sys-

tem can be installed in almost every vehicle, regardless of the

manufacturer.

POWERFULThe Hydraulic Power Pack indeed does justice to its name. An axle

loaded with 12 metric tons can be steered in standstill from the left

stop to the right stop in less than four seconds.

INTELLIGENTThe Hydraulic Power Pack communicates via CAN bus with the

safety steering computer. Thus the direction of rotation of the en-

gine, the speed and the engine status of the Hydraulic Power

Pack and with it the movement of the auxiliary steering axle are

monitored and controlled.

EASY INSTALLATION AND ADAPTIONThanks to the integrated hydraulic block the Hydraulic Power

Pack is directly connected to the steering cylinder which means

less piping and less installation time. Furthermore less cable is

required since no proportional valves have to be actuated. The

Hydraulic Power Pack can be installed where space is available.

HIGH SAFETY LEVELAlso with the Hydraulic Power Pack important functions of the

auxiliary steering system can be realised with safety level ASIL D.

PLUG-AND-PLAY (OPTIONAL)Optionally you can get a completely wired stainless steel box, in

which a safety steering computer, the hydraulic tank and the

Hydraulic Power Pack are already installed. The connectors and

hydraulic connections are located at the outside, so that a real

plug and play solution is available.

Hydraulic

Power Pack

ASIL D NEW

Safety Angle

Transducer

4–7 System Design

6–6 Specification of software safety

requirements

6–8 Software unit design and implementation

4–8 Item integration and testing

6–7 Software architectural design

6–10 Software integration and

testing

6–11 Verification of software safety

requirements

6–9 Software unit testing

Item testing

Test phase verification

Software testing

Test phaseverification

Software testing

Test phaseverification

Design phaseverification

Design phaseverification

Design phaseverification

Softwaretesting

Test phaseverification

Test

pha

ses

Design phases

Scop

e of

Par

t 6

Scop

e of

Par

t 4

Scope of Part 4

Scope of Part 6

6–5

Initi

atio

n of

pro

duct

dev

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men

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oftw

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The processes required for it were already implemented in the

company a few years ago. The result is an ISO 26262-compliant

development process for our electronic components. At the same

time, we remain flexible enough to fulfill individual customer re-

quirements.

This interactive software tool has been developed by us and

matched to the requirements of our customers. PCSnext sup-

ports you during commissioning, maintenance and diagnostics of

the EHLA® auxiliary steering systems. It is designed for develop-

ment and commissioning staff, service experts and for the End-

of-Line-process.

Benefits

➞This user-oriented service tool can be installed on any laptop

and connected with the safety steering computer.

➞Manufacturers of vehicles and automobile repair shops can do

their software updates, diagnostics and parameter settings at

the EHLA® steering system.

➞An external access via TeamViewer is possible.

For simple diagnostic functions the free-of-charge tool

PCSnextLite is available.

UDS (Unified Diagnostic Services) has become established for

the vehicle diagnostics in mass production of commercial ve-

hicles. This interface was implemented by MOBIL ELEKTRONIK

according to ISO 14229 and the safety steering computer can

optionally be prepared for UDS.

Benefits

➞The EHLA® auxiliary steering system can be processed in the

manufacturer‘s diagnostics system of the vehicle without any

additional software.

➞A comprehensive diagnostics of the EHLA® auxiliary steering

system is possible via UDS, so that also I/O‘s can be read and

controlled.

➞End-of-Line Process: The axle alignment or the End-of-Line

parameterisation of the EHLA® auxiliary steering system can

also be done via UDS.

The task of the vehicle manufacturer is to carry out the hazard

analysis and risk assessment. This results in the safety require-

ments for the auxiliary steering system. With the latest generation

of safety steering computers from MOBIL ELEKTRONIK, safety

functions up to ASIL D can be implemented.

ISO 26262 – ALREADY IMPLEMENTED TODAY AT MOBIL ELEKTRONIK

DATA EXCHANGE WITH EXTERNAL SYSTEMS AND SYSTEM DIAGNOSTICS

PCSnext TOOL FOR SERVICE AND DIAGNOSTICS

UDS (UNIFIED DIAGNOSTIC SERVICES)

HIGHEST SAFETY LEVEL ASIL D

C1 C2 C3

E1 QM QM QM

E2 QM QM QM

E3 QM QM ASIL A

E4 QM ASIL A ASIL B

E1 QM QM QM

E2 QM QM ASIL A

E3 QM ASIL A ASIL B

E4 ASIL A ASIL B ASIL C

E1 QM QM ASIL A

E2 QM ASIL A ASIL B

E3 ASIL A ASIL B ASIL C

E4 ASIL B ASIL C ASIL D

Source: ISO 26262-3:2011 | Table 4

S 3

Controllability classSeverity class Probability class

S 1

S 2

The new ISO 26262 requirements often

present great challenges for our customers.

We gladly assist you with our know-how in

this area and more than 45 years of expe-

rience in the design of auxiliary steering

systems.

Ask us for a workshop regarding the topics

Functional Safety / HARA / Safety Concept.

FUNCTIONAL SAFETY

Safety Steering

Computer

Axle Integrated

Safety Angle

Transducer

EHLA® STANDARD FOR COACHES – OPTIMISED FOR YOU

Coach buses are equipped with a steered rear axle. For this

application our EHLA® STANDARD has proven since years. This

auxiliary steering system has also been further optimised for you.

With the latest generation of safety steering computers from

MOBIL ELEKTRONIK, safety functions up to ASIL D can be im-

plemented.

If the vehicle is equipped with an ESP system, the safety steering

computer can access the steering wheel angle via CAN bus. This

means that no safety angle transducer is required for the front

axle. This saves assembly time and reduces the number of com-

ponents.

THERE ARE ALSO VARIOUS POSSIBILITIES OF APPLICATION FOR BUSES

MORE THAN JUST A HIGHLIGHT – THE SYSTEMS HAVE PROVEN THEMSELVES THOUSANDS OF TIMES

MULTI-ARTICULATED BUS

For these complex vehicles the steering of multiple rear axles is

realised by using EHLA® FAILOP. The articulation angle is also

monitored and taken into account by the EHLA® auxiliary steering

system. This auxiliary steering system achieves the highest

safety levels.

BUS STOP AUTOMATIC

A LOT OF SPECIAL FEATURES AVAILABLE:

DOOR COLLISION PROTECTION

When the doors are opened, the system automatically switches

to bus stop mode. After closing the doors and continuing driving,

the rear swing-out suppression is activated in order not to endanger

waiting pedestrians with the rear of the vehicle.

This feature is important, if the back doors of the bus are assem-

bled very close to the steered rear axle. Before opening the doors,

the steering axle is set straight to avoid a collision between door

and axle.

ARTICULATED BUS

The articulation protection of the joint is realised with a safety

steering computer by MOBIL ELEKTRONIK for this buses.

With the latest generation of safety steering computers from

MOBIL ELEKTRONIK, safety functions up to ASIL D can also be

implemented for articulation protection. Integration into the vehicle

control system is possible via CAN bus.

© MAN Truck & Bus AG

Safety Angle

Transducer

ProportionalHydraulic Unit

ASIL D

LENKUNGSteer-by-Wire ARBEITSFUNKTION

Control-by-Wire

FAHRANTRIEBDrive-by-Wire

BREMSEBrake-by-Wire

MOBIL ELEKTRONIK GMBH

Bössingerstraße 33 . D-74243 Langenbeutingen

Phone +49-7946-9194-0 . www.mobil-elektronik.com

ABOUT MOBIL ELEKTRONIK

Introducing the first steer-by-wire systems for heavy duty vehicles

MOBIL ELEKTRONIK has taken a pioneering role in system techno-

logy for mobile automation since 1973. Because a safe and reliable

system is more than the sum of its individual components we

strengthen our core competences safety technology and systems

engineering continuously. This development led to numerous inno-

vative and groundbreaking solutions and we are proud to have

substantially filled terms like steer-by-wire und control-by-wire

with meaning.

What started as a small engineering office has developed into an

internationally active company with more than 110 highly motivated

employees. Our complete systems can be found in all areas of

commercial and special-purpose vehicle construction today. © M

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OVERVIEW OF EHLA® SYSTEMS

Auxiliary steering system for self-tracking

tag axles and pusher axles

Auxiliary steering system for locking axles

Auxiliary steering system for driven,

steered rear axles with centering device

Auxiliary steering system for multiple

steered rear axles

Redundant fail-operational auxiliary

steering system

Auxiliary steering system for 2-, 3- or 4-axle

agricultural trailers

Auxiliary steering system with independent

hydraulic supply for semitrailers

Auxiliary steering system with independent

hydraulic supply