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8/10/2019 Hydractive Citroen Official Training Manual
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TECHNICAL TRAINING
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HYDR CTIVE SUSPENSION
INTRODUCTION
The choice of spring and damping settings of a vehicle's suspensionis
based on two maintriteria.
I - COMFORT
The flexibility and the damping rate are defined so as to isolate theoccupants of the vehicle from
impads
and vibrations by using anoscillating frequency btween0.9 and1.2 Hertzand by limiting verticalaccelerations to 0.25 g (2.45 mls2).
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I
PRINCIPLEOFHYDRACTIVESUSPENSION
For a vehicle t o be comfortable, i t s suspension must be set t o be supple
in flexibility, damping and anti-roll.
These settings do not allow themovement of the vehicle to be
controlled properly when disturbed. In this case, firm suspension isneeded which reduces comfort.
Standard suspension is a compromise defined as a function of the typeof vehicle (family or sports). The role of hydractive is to offer these two
types of settings and to select the ideal solution automatically asa
function of the driving conditions:
No disturbance :supple suspension promoting comfort,
Disturbance: firm suspensionto control themovementso f the vehicle
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Switching t o firm by anticipation
The computerwin switchto the firm position asa function of theevents which risk compromising the stability of the vehicle. The
suspensionwill therefore becomeharder before the vehiclehas
moved.
Switching t o firm by reaction:
EVENT ,
Bend
Steering wheelturned
Request for power
Engine brake
Braking
Th i h h fi i i f i f h
VALUE MEASURED
Angle of rotation
Rotational speed
Development speed
of the acceleratorpedal
Front brake pressure
SENSOR
Steering wheel
Steering wheel
Accelerator pedal
Brake
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* Example of the new laws for switching from the supple state to the
"firm"state.
On the motorway at 120 kmlh(75 mph), in the "auto" position,
switching to "firm" occurs for a steering wheel angle greater than
33 degrees, thisstate i s maintained for 1.2 seconds when the
steering wheel returns to an angle less than 33 degrees. In the
same configuration, in the "sport"position, switching to "firm"
occurs for an angle of 22degrees and this state is then maintained
forl 6 seconds.
On country roads or in town, at 50 kmlh(31 mph), switching to"firm"occurs for a steering wheel angle of 120degrees (a third of
a turn of the steering wheel) when in the"auto
"position and the
time delay is1.2 seconds. In the same conditions, in the "sport"position, switching from supple to "firm" occurs for an angle of 80degrees and this time the time delay is 1.6 seconds.
I VARYING THESPRING
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B - THE HYDROPNEUM TICSPRING
Nitrogen
Membrane
Fluid
The elastic element consists of a
mass of nitrogen of which t he
pressure and volume vary as a
function of the force F applied to
the piston
i
.
Piston
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Comments:
When thevehicle is loaded the volume of nitrogen inthe spheres
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I1
VARIABLE DAMPING
This consists of putting two shock absorbers in parallel and isolating, ornot, one of them to vary the damping.
A - SOFT POSITION
The fluid passes through A towards the main sphere and throughA towards
the additional sphere. Fluid braking is low since the
fluid can flow in two ways +damping is low.
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ANTI-ROLL
-REMINDER OF HOW STANDARD HYDROPNEUMATIC SUSPENSIONWORKS
\
Direction of roll
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B - ACTIVE ANTI-ROLL OFHYDRACTIVESUSPENSION
The circuit i s modified with respect to the standard system in theboth states.
1 - "Soft" state
Vd
Shock absorber
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10
PRESENTATIONOF THE ASSEMBLY
SUMM RY DIAGRAM
Inputs
Outputs
ront stiffness regulato r
SPORT control control electrovalve
Steering wheel
sensor
Vehicle distance
M
ensor
P
piegulator
Light on SPORT
switch
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- POSITION
L M NT
POSITION
Steering wheel sensor
On the steering column behind the steering
wheel
Computer
Control switch
Vehicle speed sensor IOn the gearbox tachometricsocket)
Ventilated housing on the front right wheel
arch under the bonnet
Central console behind the height control
lever
-
Front stiffness regulator electrovalve
Behind the cooling radiator at the front l e f t
Accelerator pedal travel sensor
Braking pressure sensor
Bodv movement sensor
On the pedal arm
-
On the front left of the engine sub-frame
-
Riqht of the front sub-frame
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DIAGRAM OF OPERATING PRINCIPLE
COMPUTER
BOOT
SWITCH
DOOR
SWITCHES
BODY
MOVEMENT
SENSOR
CCELERATOR
PEDAL
SENSOR
SUSPENSION
SWITCH
I
T
VEHICLE
SPEED
SENSOR
STEERING
WHEEL
SENSOR
\
I
v
v
~r
~r
I
7
f
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13
OPERATION OF THE HYDRAULICPART
PRESENTATION
Parts list
1 Front electrovalve
Front stiffnessregulator
Rear electrovalve
Rear stiffnessregulator
Front heightcorrector
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The system differsfrom standard suspension due to the addition of tw
stiffness regulators and (one per axle) each incorporating an
electrovalve.
Note that the pipes connecting the suspension elements to the
regulators havea large diameter (8X
10) in order to reduce load losses
and therefore the response time. Sealing is provided by I S 0 taperedconnectors without gaskets. The tightening torque is 3 to 3.5 mdaN
THE ELECTROVALVE
A-
ROLE
This allows the stiffness regulator to be controlled hydraulically
according to the electrical information it receives from the
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C - OPERATION
I At restAs the coil (5) is notenergised, the spring 1)presses the needle (2) ontothe seat (6).
The following are connected
B
A . L
The user circuit output B i stherefore connected t o thereservoir C.
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D - CHARACTERISTICS
Nominal voltage 13 5V
Nominal intensity 3 A when powering up for 0.5 seconds with
the maximumvoltage.
0.5A when holding by disconnectingthesupply voltage
Maximum cut-outtime < 1.8ms
Resistance 4.8
Control frequency l000z
Hydraulic
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THE STIFFNESS REGULATOR
A ROLE
Two stiffness regulators are fitted (one front and one rear) which
modify the physical state of the suspension as a function of the
status of the electrovalve.
B - CONSTITUTION
Parts list
1 Additional Sphere
3 - Slide valve
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18
C - OPERATING PRINCIPLE
l "Soft" state
HighPressure
Reservoir
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When the electrovalve is energised, the slide valve (3) is subjectedto the high pressureHPon one side and to the suspension pressure
PSon the other.
SinceHP>PS
the slide valve is locked in the "Soft" position.
There is thereforea link between the two suspension elements
and the additional sphere.
This gives:
Large volume of gas (suspension spheres additional sphere)
- soft suspension.
Fluid passes through four shock absorbers (to reach thedditi l h th fl id th h th h k
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2 "Firm" state
HighPressure
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Sthe electrovalve is not energised, the slide valve (3) is subjected to thesuspension pressure PSon one side and to the reservoir pressure
Pr
on theother. Since PS Pr, the slide valve is locked in the "Firm" position.
The additional sphere is therefore completely isolated and the main link
between the two suspension elements i s broken.
Therefore, there is :
Small volume of gas (additional sphere isolated)
Firm suspension
Fluid no longer passes through the shock absorbers(5) since theadditional sphere i s isolated.
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111- STIFFNESS REGULATOR BALL VALVE
A - ROLE
This allows:
In the "Firm" state, the suspension elements to be connectedt
the height corrector during correction or,
e The suspension elements to be isolated for roll, thereforepreventing fluid flowing between the two spheres.
B CONSTITUTION
Parts l i s t
1 - End Stop
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3 - OPERATION
1-
Anti roll When rolling, fluid tends to flowfrom one suspension element tothe other. Itmoves the ball (5)which presses against the seat 4),thus closingthe connection.
As the pressure of the compressedsuspension element is greaterthan that of the extendedsuspension element, the ball i slocked whilst the vehicle is rolling.When the roll stops, there is nolonger any transversestrain onthe vehicleand the ball isreleased.
4 5 6 When turning in the oppositedirection, the ball i s pressedagainst the seat (6)
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3 Outlet correction
Under the effect of the fluiddischarged by the suspension
elements, the ball presses againstthe thrust rod 2) .This thenpresses against the end stop l ) , ti s therefore locked in this positionand does not prevent the fluidflowing.
At the end of the correction, theflow is zero and the ball isreleased.
25
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25
ELECTRONIC OPERATION
I PRINCIPLE
The suspension has two stiffness states and two damping states.Changes in state are controlled by anticipationbyone of the four
parameters of steering wheel angle steeringwheel speed, braking andthe amount the pedal is pressed down
a weH
asby analysing thevertical movement of the body (amplitude of the movement).
The parametersfrom the sensors are compared with variable
thresholds as a function of the vehicle speed. The state changes t o firmwhen the threshold is exceeded; returning to the supple (or soft) stateoccurs when the value of
the parameter is once again lower that thethreshold and after a time delay has elapsed.
COMPUTER
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B - CONSTITUTION
This i s a sealed unit into which are fitted the various electroniccomponents.
The link to the outside i s provided by two connectors each withfifteen channels (one white and one black), which can bedisconnected in any order.
The heart af the computer consists of two TEXAS INSTRUMENTS16kB and
4kB
microprocessors.
The control transistors of the electrovalves (called "intelligent")
are capable of detecting open circuit and closed circuits.
Integrated circuits monitor the supply voltage and protect thecomputer.
C CHARACTERISTICS
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111- SENSORS
A
-
SPORT
CONTROL SWITCH
1
Role
This allows the driver
to
impose the
SPORT
rule.
2
-
Constitution
-
Operation
.
+
ights
I
B 4
C
P
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B - EATON SPEED SENSOR
a) Role
This sensor supplies an electrical signal which is proportionalt o the rotational speed of the secondary gearbox shaft, andtherefore t o the vehicle speed.
b) Position
It is mounted onto the tachometricsocket of the gearbox
c) Operation
1 - Polar wheel
2 H ll
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The essential element of this system i s a plate of 1.2mm length.
current passes over this plate between points and
B.
If
there
i s
no magnetic field, no voltage is obtained between-the equidistant
points E and F.
When a
S N
magnetic field i s applied a t right angles to the plate, a
very low Hall voltage of 0.001 volts
i s
obtained between points
E
and F.
This comes from the deflection of the A B current l ines by the
magnetic field, provided that
the
two simultaneous conditions of
electric current and magnetic field are satisfied).
Operation
Speedo cable
circuit
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d) Calculating the speed
The sensor supplies square signals, of which the frequency isproportional to the speed
We know that the sensor supplies:
- Eight pulses per revolutionof the polarwheel
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C - STEERING WHEEL SENSOR
1 Role
This generates signals which enable the computer to definethe angle and the speed of the steering wheel.
2 Constitution
It is a double optoelectronic sensor. It consists of two l ightemitters, two receivers and a phonic wheel with windows. Thesensor is fixed and the phonic wheel tur s with the steeringwheel. The phonic wheel and the sensor form a compactaleo
make unit, indexed in rotation.
Parts l is t
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3 Operation
Reminder of a photodiode
A photodiode is made from a PNjunction which can beilluminated externall . Its reverse conductivity isproportional to the il umination.
Light
Junction
Inverse voltage:l0V
0 10 20 30
Radiation
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W e therefore have:
A ~ O O O O O O O
A - Emitter
-c
B
L
Receiver
C
Phonic whee l
D Displacement
S Output
4
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d) Operating principle
The computer supplies the sensor with + 5 volts.
C + 5Vsupply
NI0
M
P
U
T
NI
5
9,5
A3
-
S11
N9
9 5
V
A1
.
S21
@
B 3 B
R
..
.
l
C 2
Jo
STEERING WHEEL
SENSOR
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5 Processing of the signal by the computer
a) Work done by the computer
Interprets the signals from the sensor (number ofsteps)
Determines the direction of rotation
Determines the straight line positionCalculates the angle of the steering wheel with~espectto the calculated straight line
Calculates the rotational speed of the steering wheel
Compares the values of the rotational speed and theangle found with the switching to firm thresholds ofthe computer.
Controls, or not, switching of the suspension to the"fi "
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c) Deterining the direction of rotation
As the computer knows the logical order of the codes, itjusthas to compare the new code with the old code to work outthe direction of rotation.
0
New1
0
New 1
0
Old - Left1
Old 1 Right
d) Determining the straight lineDefinition of the "calm steerinq wheel" notion
The steering wheel i s said to be "Calm" when i t s movementsremain within a sector of + 6.5" with respect to a zero point
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The new position of the steering wheel becomes the newpoint
PO, a newse tor
of13
centred aboutPO i s created and
therefore the steering wheel becomes calm, the distancetravelled counter returns to zero and the computer calculatesthe average of the steering wheel positions in this sector.
Definition of distances
The following are known as:
D distance over which the computer has calculated thestraight line,
[BP distance travelled with the steering wheel calm
Application:
Steeringwh i calm 1 Steeringwheelnot calm Steeringwheel calm 2
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Updatinq the straiqht I ine
The computer memorises the straight line osition LD (average of thepositions in the sector: Sum of the num er of steerinq wheel positions
number of acquisitionsand th e distance D over which it has been calculated.
The first straight Iine memor.ised LDo is the position of th e steering whee lwhen Vveh = 30 kmlh PO), therefore the distance memorised i s D
=
0.
A new straight line LDwill
be memorised (average o f the positions in t hesector) as wel l as the distance D over which it was calculated if one of theset w o events arises:
Distance travelled with steering wheel calm DP more than 50 metresthant ha t memorised D: DP = D + 50. Therefore, for as long as thesteering wheel is calm, updating w il l occur every 50 metres, t hememorised distance D increasing by 50 m.
Example :distance memorised D = 500 metres. Af te r travelling adistance DP = 550 metres with steerin wheel calm steering whee lposition updated and Dbecomes equa t o 550 metres Then a t DP
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e) Measuring the angle
The computer counts the code changes emitted by the sensor
with respect to the straight line it has defined.
f
Measuring the speed of rotation
The computer counts the code changes emitted by the sensorin one second.
NOTE:
The
ECU accepts rotational speed signals of up to 2.5" per milli secondfrom the steeringwheel sensor. Any value above this threshold has the same effect.
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SYNOPTIC FOR DETERMINING
STRAIGHT AHEAD POSITION
VS 18
MPH
+6.5
around PSW
DT
0
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D - ACCELERATOR PEDAL TRAVEL SENSOR
1 - Role
This enables the computer to know theposition of theaccelerator pedal.
2 Constitution - Operation
It consists of a variable resistor, of which the cursor i scontrolled.bythe pedal.
Parts
i s t
1 -Protective resistor
2 - Receiving track
3 -Cursor
4 - Resistor
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Characteristics
Main resistor
Protective resistor
4
Computer processing of the signal
a) Work performed by the computer
Reads the sensor voltage with the accelerator pedal
in he 'throttle closed' position and the sensor
voltage with the pedal in the 'throttle open' position.
Deduce the actual electrical stroke of the sensor from
this information.
Divide this actual stroke into a certain number o
steps.
Check how many steps are covered in 32 ms (speed a t
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Previously, the throttle closed position should have beenbetween 10 and 30% of the total theoretical electricalstroke; this was too restrictive and from now on thecomputer will use a minimum effectiveelectricalstroke of100steps for analysing the development of theaccelerator pedal.
The computer has the total electrical stroke stored in i t smemory 0 to 5V,divided into 255 ste which gives avalue of 0.0196 V per step. It is consi4ered that, with thesensor fitted, the throttle closed' should be a maximumof 125 steps, thus giving a minimum effective stroke of
100 steps.
In reality, the computer knows how to adapt t o al lsituations.
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Example:
255 steps divided by 5 V gives a value of 0.0196 V fo r one step.
In theory:
- th ro tt le closed = 125 steps+ 2.45 V- thro tt le open = 255 steps A step = 100 steps = 1.09V
2.45 + 1.96 =4.41- 35 st ps + 0.6V - 0 t o 0.6V =Short circuit fau lt zone- 233 steps 4 5V - 4.5 t o 5 V = Open circuit fau lt zone
The driver swtiches th e ign it ion on:
- The computer reads 1.96 V; 1.96 < 2.54 V (throt tle closed a t 125 steps)
The computer takes these values of 1.96V thus 1.96 + 1.96= 3.92 V. It
therefore has aminimum effective stroke o f 100 steps between 1.96V(throt tle closed) and 3 92 V (throt tle open).
- The driver presses the accelerator pedal and t he computer receives avoltage of 4 47 V; 4 41 V (thrott le open a t 255 steps);
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E - BRAKING PRESSURE SENSOR
This i s a pressure switch i s closed a rest
Nll
B 2 B11
It i s closed for a braking pressure S 35 bar and open for a brakingpressure > 35 bar.
The computer reads the electrical signala t i t s terminal N 11:
If P 35 bar > earth signal,
If P > 35 bar > ''OpenN-- 5 V
F BODY MOVEMENT SENSOR
Role
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3 Operation
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5 Processing of the signal by the computer
a) Work performed by the computerInterprets the signals from the sensor (number of steps)
Determines the direction of rotation of the ring (leadingor trailing)
Calculates the displacement speed
Determines.. the. average height (Have) and updates it. . ... :
Calculates the movement by the difference with theaverage height
comparesthe movement values found with the switchingto firm thresholds of the suspension
, Controls, or not, switching of the suspension to the"firm" state
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G - THE DOORSAND T ILG TE
The aim of the door or tailgate switches is to provide an earthsignal to the computer or not.
They are used for the anti-jolt function which will be discussedlater. The earth s i nal is present when one of the doors or thetai lgate
is opene
Contacts open, a voltage of 12 V is measured at terminals B6and87
.
.
B
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IV STRATEGIES FOR SWITCHING TO FIRM
A PRINCIPLE ELECTROVALVE CONTROL
Normally, the suspension is "supple" (three spheres per axle); thecomputer switches to "firm" (two spheres per axle) via one of thefollowing parameters :
Steering wheel angle( steering wheel sensor
Steering wheel speed )
Amplitude of vertical movement in bothdirections bodymovementsensor
.. .,,
..
Braking brake sensor
Speed the accelerator pedal is being pressed or lifted- pedalsensor
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B -
SWITCHING TO FIRM IN ANTICIPATION
1-
Steeringwheel
a) Using th e angle of rotation
The vehic le speed must have exceeded
30
km h on ce and
the angle must be reater then a l im i t w h ich
IS
a function
f t he vehicle spee .
The suspension wil l return t o soft w he n t h e st ee rin g
wheel angle becomes less than a li m it value
and
a f te r a
1.2 s t imer.
Note:
In the s o r t position, each lim it fo r sw itching t o firm
i s
divide
B
y
1.5
and the timer for retur ning
to
soft
is
mult ipl ied by 1.3.
STEERING WHEEL ANGLE LIMITS
Norm al position)
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FIRM
STEERINGWHEEL
ANGLE
LIMITS
Normal position)
1605
600
5
l
-
1
1
I s 5
.
400
Steering
wheel
angle
degreesh) 300
-
200
-
--
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Specific case of steering wheel centring
Through experience, it has been realised that the steering wheelalways returns to the straight line osition quicker than when it
fmoves to the turning position, wit out itbeing necessary to switchto firm to stabilise the vehicle. Thus, the limits for switching tofirm on the steering wheel return are higher than when turning,and overshooting the straight line posit~onwhich always happens,
i s also filtered.
The limits for switching to firm based on speed are multiplied btwo during the phase when the steering wheel is returning t o t estraight line position and for a ossible maximum overshoot of 170
The straight line position is saif
to have been overshot when thesteerng wheel passes through this point a t a speed greater than130
per second. If, when returning the steering wheel t o thestra~ghtlineposition, a limit for switching to f ~ rmis exceeded, thesoft state will be reinstated when the value becomes less than thisli it d ft d ti
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2- Accelerator pedal
After the ignition has been switched on, the vehicle speed musthave exceededS kmlh once in order to switch tothe firm state.
If the rateof change of the accelerator pedal is greater than a limitwhich is a function of thevehicle speed, the suspension will switchto the 'firm' sate for:
l 2 ifthe vehicle speed 140 kmlh pedal released orif the vehicle speed
>
140 kmlh pressed down
The limits for switching to firm are different depending onwhether the accelerator pedal i s being pressed down or released.
Note: In the sport position, each limit for switching to firm i sdividedby 1.5 and the timer for returning to soft ismultipliedby 1.3.
Itshould be noted that the higher the speed, the higher the limitfor switchingto firm(parallel relationship)
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ACCELERATOR LIMITS(RELEASING)(Normal position)
FIRM
Accelerator
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Considering the vehicle acceleration
if after
a switch to f irm caused by the accelerator, the acceleration or
deceleration of the vehicle is greater than four pulses in 512 ms = 1/2 persecond , the firm position is maintained for the whole time during whichthe limit is exceeded (3 pulses in 512 ms) with a minimum duration of 0.8seconds.
Example:
The vehicle is travelling at 36 kmlh which correspondst o 50 pulses persecond and 25 pulses1500ms. If,during the next 500 ms, the speed sensorsends28 pulses (3 additional pulses), the vehicle is ten travelling at:
in other words, 4.3 kmlhmore than before. Therefore, inone second, thevehicle has acceleratedby4.3 2 = 8.6 kmlh. This is not sufficient tomaintain the firm position; the computer would have had to receive moreth 28 l i th t 500
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Features Fault l Effective
:
stroke l
Fault
---------------
I
Throttle
: Throttle j
SC I closed
100
steps Open I
oc :
J
l
l
I
i
I
~ o ~ t e p s l
.
l
4
5
3
245
1
I I
l
l I
1
l
l
:
V
ref-min tolerahce
V
ref-max
I Ref-diap
Zk Acc
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C - SWITCHING TO FIRM BY REACTION
Body movement
The vehicle speed must be greater than 10 kmlh and themovement (attach or release) must be greater than a limi t as afunction of the vehicle speed.
The limits are different depending on whether the movement is in
the 'attach'direction or the release' direction.
The suspension wi ll return t o the soft state when the amplitude ofthe movement is less than a limit value and after a 0.8s timer.
Note:
n the sport position, the limits for switching t o f i rm as well as thetimer remain unchanged.
BODY MOVEMENT LIMITS(ATTACK)(Normal position)
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BODY MOVEMENT LIMITS (RELEASE)(Normal position)
Frontsuspensionmovementmm)
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Features
Wheel impacts
If the movement speed i s greater than 0.3 mls, the limits take the value of60 mm for 0.4 seconds.
Uneven roads
If the limits take the value of 60 mm for 0.4 seconds, and if this occurs morethan three times in three seconds, the limits takes the value of 60 mm forthe next two seconds.
The wheel impact and uneven road functions are not applied:
If vehicle speed > 159 km/h
the steering wheel angle is greater than half the 'firm'limit for the steering wheel angle at the consideredspeed.
Example: The vehicle is travelling at 120 kmlh
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V - VEHICLE ANTI-JOLT
A VEHICLE LEVELLING
We have seen that when the supply to the computer i s cut, thesuspension is in the "Firm" position (Uelectrovalve= 0).Therefore the additional sphere i s isolated.
If the pressure in the main spheres varies (passengers getting in orout, loading drunloading) a pressure difference with respect tothe additional sphere appears.
When the ignition is switched on, as the additional sphere isconnected to the circuit, the pressure difference translates as ainflux (P additional > Pmain) or a reflux(P additional< Pmain)of fluid in the suspension cylinders, which suddenly alters the rideheight of the vehrcle and causes the vehicle to jump.
ROLE
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- SUMMARY OF OPERATION
+ Ignition
Doorcontact
+ Ignition
IElectrovalvecontrol
Doorcontact
t l0mins
ledrovaive
3 s
.
Qs .
I
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then it:
Reinitialises thecounters
registers, etc...
Illuminates the central warning light for three seconds orcausesit to flash for ten seconds a t a frequency of 1 z if afault is memorised.
C SELECTING THE DATA TABLES
The computerhas in i t s memory the tables of parameters for allthe vehicles which can be fitted with hydractive suspension.
When initialised, the computer reads a code which tells itwhich
table of parameters it should use.
If this code does not exist or i s wrong, the computer systematicallychooses the table o f parameters of the
XANTIA
vehicle andswitches the warning light on permanently.
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AUTO-DIAGNOSTIC
I - GENERAL
The auto-diagnostic has been designed with the aim of improvingreliability and preserving
automat~c
operating for as long asposs~ble
Where it is impossible to control the electrovalves (computer broken,electrovalve connector disconnected, supply voltage too low), thesuspension is in the "firm" state hydraulically. On the other hand, forsensor faults, the suspension is maintained in the "supple" position.
1 Steering wheel, accelerator sensors, electrovalves, computerThere are two types of diagnostic:
By coherence of the signals between themselves.
3 Electrovalves
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3 Electrovalves
The two electrovalves switch to the "firm" position.
4 - Computer
Attempts to reinitialise the computer result in the suspensionswitching to firm for a few seconds.
CMEMORISING FAULT CODESFaults are stored in a non-volatile EEPROM memory (faults arenot erased when the battery is disconnected).
D - CHECKING THE SYSTEM
An after-sales testunit and the suspension computer can beconnected in two different ways:
m Slow rate with coded signals with the OUT 4097Tor OUT4120 Ttools
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arameters: steering wheel angle, vehicle speed,patteryvoltage....
With the behicle stopped, the tester can force thecomputer to operate an electrovalve anda warninglight.
These two functions therefore aloow a compltefunctional test of the suspension system to be carriedoutwithout having to work on the vehicle wiringloom. This test can be static or dynamic.
Computer identification
This gives the hardware and software versions, thecomputer parametersand i t s serial numbers.
Loading theparameter table selection coderemotely
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EMERGENCY
STRATEGY
ANNULLED OR
VALID.
COUNTER
FAULT
U
battery
within
range
11.5V-16V
_
0.5Vfor2s
relaunch
att emp t every
30
S
relaunch
att emp t every
30
S
EMERGENCY
STRATEGY
firm
suspension
firm
Suspension
firm
VALIDATION
60
1
9
TEST Y
SIGNAL
COHERENCE
ELE
C.
TES
T
X
X
X
DETECTION STRATEGY
U b c 1 1V fo r2 s
u b > 16.5Vfor 2 s
Electrovalve control
incoherance < 10 ms
during full voltage
control o f 500 rns
Electrovalve control
incoherence for 500 ms
ANOMALY
DETECTED
battery voltage
outside range
microscopic
supply
breakage
FUNCTION
TESTED
SUPPLY battery
or earth
ELECTROVALVE
FAULT
CODE
DIAG.
WITH
CODED
SIGNALS
53
Front EV)
31
Rear EV)
3
2
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FUNCTION
TESTED
STEERING
WHEEL
PRESSURE
SWITCH
FA ULT
CODE
DIAG.
WITH
CODED
SIGNALS
23
2 1
ANOMALY
DETECTED
Open circuit
n o t w o r k i n g
short circuited
open c i rcuit
short circuit
DETECTION STRATEGY
I
measured
> I
ef max
I
measured < I re f m in
fo r
if
Ve h Sp < 100 kmlh
afte r ignit ion, st. wheel
angle 6.4 for 1 km or
having had a st. whee l
an le > 6.4Oonce:
l
t. W eel angle .4
f o r 3 k m
if
V > 100 kmlh, n o
detect ion
F = l a c c e l > l 5 % f o r
10
S
speed
>
30 kmlh
accel . no t at faul t
speed
>
30 kmlh
no brake in fo
3
decels o f 0.469 in 1 S
ELEC.
TEST
X
SIGNAL
TESTBY
COHERENCE
X
X
X
VALIDATION
4
3
5
5
EMERGENCY
STRATEGY
automat i c
suspension
automat i c
suspension
EMERGENC
STRATEGY
ANNULLED O
VALID.
COUNTER
FAULT
I ref min
15
and no spped signal
for 30
speed O f f 0 kmh
n 512 ns (V > 0 krnlh).
Vl5
speed>30 krnlh and no
transition in the 5
followin the brake
l
witc signal
V signal
>V
ref max
V signal< V ref rnin
for
2
ELEC.
TEST
X
TESTBY
COHERENCE
X
X
X
-. .------------.----------.-------.----------------
VALIDATION
5
5
1
EMERGENCY
STRATEGY
V = 100 km/h
automatic
suspension
automatic
suspension
EMERGENCY
STRATEGY
ANNULLED
OR
VALID.
COUNTER
FA
ULT
signal return
coherent for
20s
movement
angle
measured >
steps
signal return
within range
for 20
signal return
w~thinange
for
2
sand
speed
=
MPH
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VALIDATION
10
ELEC.
TEST
X
X
DETECTION STRATEGY
interna l watchdog
EEprom Check sum
te st EEPROM erasu re
+
readJwrite test
sendinglreceiving test
w hen compu t e r
enerqised
tatu us I npu t w es t
f o r 2 S
Electrovalves no t
cont rol led
EMERGENCY
STRATEGY
reset ip
f i rm susp.
if
V>40
k m l h
f unc t i on
no r ma l w he r e
~ o s s i b l e
fau l t codes
em i t t ed
y
w a r n i n g l i g h t
f i r m
suspension
TEST
IGNAL
Y
COHERENCE
X
X
ANOMALY
DETECTED
p r o g or # p
f au l t
EEPROM
m e m o r y f a u l t
d ~ a g . ~ n e
tlectr valve
con t rol stage
shor t c i rcuited
or open c i rcu i t
FUNCTION
TESTED
COMPUTER
EMERGENCY
STRATEGY
ANNULLED O
VALID.
COUNTER
FAULT
Status
I npu t f o r 2
o n th e 2 stage
FAULT
CODE
DIAG.
WITH
CODED
SIGNALS
54
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- COMPUTER CONNECTIONS
WHITE CONNECTOR
1 - Positive supply of front electrovalve
2 - Positive supply of rear electrovalve
5 Diagnosticline
6-
Tailgateswitch earth signal7 - ~ o o rswitches earth signal
8 - Earth1 - Control through earth of test light
11 - Vehicle speed information
12 - Normal rule (earth)/sport rule( openV)signal
13 - Steeringwheel sensor-
14 - Positive supply of illumination of switch light in sport" position
15 - Earth
DASHBOARDLIGHTOPERATION
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I l l DASHBOARDLIGHTOPERATION
It is supplied directly on the after ignition side 12V) andi s
controlled on the earth side by the computer.
m Ignition switched on the light lights up for three
seconds
Presence of a fault the light flashes for ten seconds a t afrequency of 1 z when driving or when the ignition is
switched on after a shorter initialisation than previously
= 1S).
m Ifthe microprocessor
i sfaulty light permanently
on
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EMERGENCY
STRATEGY
suspension
firm
suspension
f irm
Suspension
f irm
VALIDATION
60
1
-,
EMERGENCY
STRATEGY
ANNULLED OR
VALID.
COUNTER
FAULT
U battery
within
range
11.5V-16V
0.5VforZs
relaunch
atte mpt every
30 S
relaunch
atte mpt every
30
S
ELEC.
TEST
X
X
X
FUNCTION
TESTED
SUPPLY battery
or earth
ELECTROVALVE
SIGNAL
COHERENCE
ANOMALY
DETECTED
batter voltage
J
utsi e range
microscopic
supply
breakage
FAULT
CODE
DIAG.
WITH
CODED
SIGNALS
53
(Front EV)
31
(Rear EV)
3
DETECTION STRATEGY
U b< l l V f o r 2 s
Ub>16 5VforZs
Electrovalve control
incoherance
100 kmlh, no
detection
F
=
1accel>15% for 10
speed > 30 kmlh
accel. no t at fau lt
speed
>
30
kmlh
no brake info
3 decels of 0.469 in 1.5 S
ANOMALY
DETECTED
Open circuit
no t working
short circuited
open circuit
short circuit
FUNCTION
TESTED
STEERING
WHEEL
PRESSURE
SWITCH
TESTIGNALY
COHERENCE
FA ULT
CODE
DIAG.
WITH
CODED
SIGNALS
3
21
VALIDATION
4
S
5
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EMERGENCY
STRATEGY
V
=
100 k m l h
au tomat ic
suspension
au tomat ic
suspension
EMERGENCY
STRATEGY
A N ULLED OR
YI LID
COUNTER
FAULT
signal return
coherent for 20
movement
ang le
measured >2
steps
s ignal re turn
. wi t h in range
fo r 20
TEST
~ G ~ ~ ~Y
COHERENCE
X
ELEC.
TEST
X
VALIDATION
5
1
5
10
DETECTION STRATEGY
accel
>
15
and no spped s ignal
f o r 3
speed dro p of
3
krn/h
in
512 rns V
>
30 krnlh).
V e 5 k m / h f o r 28
fo l low ing d rop and
accel >l5
speed>30 kmfh and no
t rans i t ion in he 5 S
fo l low in the b rake
f
witc signal
Vs ignal >V ref max
V signal< V ref rnin
f o r 2 s
ANOMALY
DETECTED
l i nk in o p e n
circuit or short
circuit
sensor bro ken
ope n c i rcu i t
b roken
short circuited
op en c i rcu i t
broke n shor t
circuited
FUNCTION
TESTED
VEHICLE
SPEED
BODY
MOVEMENT
ACCELERATOR
FAULT
CODE
DIAG.
WITH
CODED
SIGNALS
24
25
22
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FUNCTION
TESTED
COMPUTER
FAULT
CODE
DIAG.
WITH
CODED
SIGNALS
54
ANOMALY
DETECTED
p r o g o r mp
f a u l t
EEPROM
memory fau l t
d ~ a g . ~ n e
t ectrOva ve
contr o l s tage
circuited
or open c i rcu it
DETECTION STRATEGY
in te rna l watchdog
EEprom Check sum
test +
EEPROM erasure
+ r e a d h r i t e e s t
sendingheceiving test
when computer
energised
@'Statusm@' Inputwest
f o r
2 S
Electrovalves n o t
contro l led
ELEC.
TEST
X
X
SIGNAL
TEST
BY
COHERENCE
X
X
VALIDATION
1
1
EMERGENCY
STRATEGY
rese t 1p.
fir m susp.
if V>4 k m l h
f u n c t i o n
n o rm a l w h e re
possible
f a u l t codes
e m i t t e d b y
w a rn i n g l i q h t
f i r m
suspension
EMERGENCY
STRATEGY
ANNULLED OR
VALID
COUNTER
FAULT
Status
Inpu t fo r 2
o n h e 2 stage