SUSPENSION OF PEUGEOT
(GROUP 9)
BETA MECHANICAL (AUTOMOTIVE)
Name :Mohd Nazmi Bin Abdul
Hamid.
Muhammad Al Hakim Bin Md Apandi.
Ahmad Azwari Bin Ab Rahim.
Islamic Calendar
Sunday, 15 April 2012
Introduction.
- Suspension is the term given to the system of
springs,shock absorbers and linkages that connects a vehicle to its
wheels.
- Serve a dual purpose-contributing to the car,s
handling and braking.
- Protects the vehicle it self and any cargo or luggage from damage and wear.
Different suspension
system :
- Conventional suspension system.
- Independent/dependent suspension system.
- Air suspension system.
- Hydro elastic suspension system.
According to William H.( n.d.), state that purpose of
suspension is:
-Make the
major friction between the tire and road
surfaces.
-Good control
of driving influence steering stability.
-Comfort of
his passengers feel secure when in the car.
Two
perspective affect automobile engineers take into account the vehicle dynamics:
Ride –
ability car to smooth out a bumpy road.
Handling – ability
vehicle to secure accelerate, brake and corner.( William H.( n.d.).
Suspension Types: Front.
Dependent Front Suspensions .
The front
wheel on the front axle depending on the font suspensions.solid dependent bar
under the front of car, place on leaf springs and shock absorbers.In the truck,
not used for years in the dependent front suspensions ( William H.( n.d.).
Independent Front Suspensions .
Can move
freely is an advantage for the front wheel in this setup. The MacPherson strut,
developed by Earle S. MacPherson of General Motors in 1947, is the most widely
used front suspension system. The double-wishbone suspension, also known as an
A-arm suspension, is another common type of front independent suspension ( William H.( n.d.).
Suspension
Types: Rear.
Dependent
Rear Suspensions .
Suspension will be easier if
double solid rear wheels in relation to car.Drive axle leaf spring in the former design, the leaf springs clamp directly to the drive axle.
The ends of the leaf springs attach directly to the frame, and the shock
absorber is attached at the clamp that holds the spring to the axle ( William H.( n.d.).
Independent
Rear Suspensions.
If both the front and back suspensions are independent, then all of the
wheels are mounted and sprung individually, resulting in what car
advertisements tout as "four-wheel independent suspension." Any
suspension that can be used on the front of the car can be used on the rear,
and versions of the front independent systems described in the previous section
can be found on the rear axles. Of course, in the rear of the car, the steering
rack the assembly that includes the pinion gear wheel and enables the wheels to
turn from side to side is absent. This
means that rear independent suspensions can be simplified versions of front
ones, although the basic principles remain the same ( William H.( n.d.).
A.Technology Invented.
PSA
Peugeot Citroën.
According to Wikipedia 11 april
2012 state that PSA Peugeot Citroën (officially Peugeot S.A., informally
PSA) is a French multinational manufacturer of automobiles and motorcycles sold
under the Peugeot and Citroën marques. Headquartered in the 16th arrondissement
of Paris, PSA is the second-largest Europe-based automaker (after Volkswagen
Group) and the eighth-largest in the world measured by 2011 unit sales. PSA is listed on the Euronext Paris stock exchange and is a constituent
of the CAC 40 index.
Hydractive.
Hydractive Suspension is a new automotive technology introduced by the
French manufacturer(PSA PEUGEOT CITROEN) in 1990. It describes a development of
the 1954 hydropneumatic suspension
design using additional electronic sensors and driver control of suspension
performance. The driver can make the suspension stiffen (sport mode) or ride in
outstanding comfort (soft mode). Sensors in the steering, brakes, suspension,
throttle pedal and gearbox feed information on the car's speed, acceleration,
and road conditions to on-board computers. Where appropriate, and within
milliseconds, these computers switch an extra pair of suspension spheres in or
out of the circuit, to allow the car a smooth supple ride in normal
circumstances, or greater roll resistance for better handling in corners. This
development keeps PSA in the forefront of suspension design, given the
widespread goal in the auto industry of an active suspension system. All auto
suspension is a compromise between comfort and handling. Auto manufacturers try
to balance these aims and locate new technologies that offer more of both (Wikipedia May 2009).
Hydractive
1 and Hydractive 2.
Hydractive 1 suspension systems had two user presets, Sport and Auto. In
the Sport setting the car's suspension was always kept in its firmest mode. In
the Auto setting, the suspension was switched from soft to firm mode
temporarily when a speed-dependent threshold in accelerator pedal movement,
brake pressure, steering wheel angle, or body movement was detected by one of
several sensors( Wikipedia
May 2009).
In Hydractive 2, the preset names were changed to Sport and Comfort. In
this new version the Sport setting would no longer keep the suspension system in
firm mode, but instead lowered the thresholds significantly for any of the
sensor readings also used in Comfort mode, allowing for a similar level of body
firmness during cornering and acceleration, without the sacrifice in ride
quality the Sport mode in Hydractive 1 systems had caused (Wikipedia May 2009).
Whenever the Hydractive 1 or 2 computers received abnormal sensor
information, often caused by malfunctioning electrical contacts, the car's
suspension system would be forced into its firm setting for the remainder of
the ride (Wikipedia
May 2009).
Hydractive
3.
As stated by Wikipedia May 2009,hydractive 3 uses a new,
incompatible orange LDS fluid, rather than the familiar green LHM mineral oil
used in millions of hydropneumatics vehicles.
The hydractive 3 hydraulic suspension has 2
automatic modes:
§ Motorway position (lowering by
15 mm of the vehicle height above 110 km/h)
§ Poor road surface position (raising by
13 mm of the vehicle height below 70 km/h)
The BHI of the hydractive 3 suspension calculates
the optimum vehicle height, using the following information:
§ Vehicle speed
§ Front and rear vehicle heights
The 3+ hydractive hydraulic suspension has 3
automatic modes:
§ Motorway position (lowering by
15 mm of the vehicle height above 110 km/h)
§ Poor road surface position (raising by
13 mm of the vehicle height below 70 km/h.
Comfort or dynamic suspension
(variation of suspension firmness)
The BHI of the 3+ hydractive suspension calculates
the optimum vehicle height, using the following information (Wikipedia may 2009) :
§ Vehicle speed
§ Front and rear vehicle heights
§ Rotation speed of steering wheel
§ Angle of rake of steering wheel
§ Vehicle's longitudinal acceleration
§ Vehicle's lateral acceleration
§ Speed of suspension travel
§ Movement of the accelerator throttle
(Picture
show by Lakshmi Anand k,2008)
History of the technology.
In World War
II, Paul Magès, with no formal training in engineering, secretly develops the
concept of an oil and air suspension to combine a new level of softness with
vehicle control and self-levelling.
1989 -Citroën
XM: Hydractive Suspension, electronic regulation of the hydropneumatic system;
sensors measure acceleration and other factors.
1990 -Peugeot
405 Mi16x4: first Peugeot equipped with rear hydropneumatic suspension.
1990 -JCB
Fastrac high speed agricultural tractor uses this system for its rear
suspension.
1993 -Citroën
Xantia: Optional Activa (active suspension) system, eliminating body roll by
acting on torsion bars. A Xantia Activa was able to reach more than 1g lateral
acceleration.
2001 -Citroën
C5: Hydractive 3 removes the need for central hydraulic pressure generation;
combined pump/sphere unit for the suspension only and with electric height
adjustment sensors.
2005 -Citroën
C6: An improved version of the C5 system known as Hydractive 3+ (also fitted to
some C5 models).
2008- JCB
Fastrac high speed 7000 series agricultural tractors now use this system for
front and rear suspension (Wikipedia May 2009) .
B.Components Identification.
The
hydractive suspension system of vehicle includes (PDF Review in operating principle) :
¨ an electronic control unit
¨ 2 high pressure electrovalves
¨ vehicle speed sensor
¨ ·steering wheel angle sensor
¨ body movement sensor
¨ a brake pressure switch sensor
¨ acceleration sensor
¨ a "sport" setting selection
switch with a built-in function warning lamp
¨ door switches
Layout of
components of hydractive suspension.
The electronic subsystem.
The
suspension ECU takes signals from the various sensors and based on two sets of
rules (one each for normal and sport suspension), activates the electric
valves. Although there are two electric valves that select the suspension
setting (one for the front and one for the rear wheels), the ECU operates them
as if they were one valve, so in effect, the ECU only has a single output
signal (PDF Review in operating principle).
The
Electronic Control Unit represents
defective though it may be by
collecting, classifying, interpreting and analyzing sensory input. Once it has
interpreted this data, it makes decisions and sends "marching orders"
to the outposts in the hinterlands (Scott
Memmer, 12.11.2000).
According to PDF Review in operating principle,the
ECU uses 7 sensors, which generate a total of 10 'input parameters':
1) Vehicle
speed
2) Steering
wheel position and speed
3) Body
movement magnitude and speed
4) Gas pedal
press and release speed
5) Brake
pressure sensor
6) Door/boot
open sensor
7) Ignition
switch on/off
C.System operation.
The operating
principle of the hydractive suspension system for the vehicle is identical .
It is a
suspension with two stiffness states and two damping states (soft/firm).
The
suspension mode changes are controlled, in anticipation, by one of the five
following parameters( PDF Review in
operating principle ) :
· steering
wheel angle
· steering
wheel speed
· braking
· accelerator
pedal depressed
· body
vertical movement
The sensor
parameters are compared with threshold figures which vary with the vehicle
speed.
As soon as a
parameter value exceeds the threshold, a change to the "firm mode"
occurs; the suspension will return to the "soft mode" when the
parameter value is again lower than the threshold and after a delay (PDF Review in operating principle).
Layout of system operation of hydractive technology.
In addition
to the height lever present on all hydraulically suspended , Hydractive cars
posess a mode switch. This enables the driver to select the normal mode, or a
firmer program - 'Sport'. With the original Hydractive (retrospectively called
Hydractive 1), selecting 'sport' simply removed the centre spheres from the
hydraulic circuit permanently. This was fine for twisty roads and/or
enthusiastic driving, but if there was a problem , the car defaulted to 'sport'
mode which most drivers found too hard for normal driving conditions. However,
Hydractive 2 the parameters were
changed. Setting the switch to 'sport' keeps the car in normal mode, but makes
to the car react and switch to the firmer settings earlier and stay there for a
bit longer before softening up again. This can easily be identified within the
car, as the switch is labelled 'Sport'/'Norm' rather than the 'Sport'/'Auto' of
Hydractive 1 (Citroen Car Club ,(n.d) ) .
Switch that
can changes the mode of the driving soft or firm mode.
D.Benefit that technology invented.
Ø
Soft
suspension for cruising and allowing the driver to cruise in comfort and still
enjoy a responsive car (Chris L.1994-2012).
Ø
It
also moves substantially towards eliminating body roll and if used for a
sportier driver will save tyre wear as well (Wikipedia May 2009) .
Ø
The
continuous self-levelling function also rids suspension design of a number of
unwanted compromises that commonly designers of steel-sprung cars have to
incorporate: as the suspension is always functioning around one predetermined
position, no matter the car's load, the various suspension-geometry issues
become a much simpler equation to solve (Wikipedia
May 2009).
Ø
As
stated Wikipedia May 2009,the same
natural law governing gases also ensures that the suspension's spring-rate
(hardness) is continuously adapted to the weight it has to carry, and to
infinite positions. For example, when the car is standing empty, the pressure
within its spheres is in balance. If one passenger enters the car, this
pressure becomes higher by the value of his weight . The car will have lost
some height, so the self-leveling system immediately reacts and brings the car
up to the predetermined ride height. The result is that the spring rate is kept
constant, regardless of the load of the car.
Ø
Hydractive
so effective is its fast-reacting brainpower. Powerful computer analysis the
data acquired by speed, g-force, throttle, brakes and gearbox sensors, then
decide the most suitable setting and activate the valves via solenoid and
sophisticate power electronics (Mark W,1998-2011).
Ø
Happen
without driver intervention,though manual selector will hold the suspension
(
Stephen H,1989) .
Comparison
before and after with hydractive suspension.
E.Conclusion.
This
technology is a technology that is useful at users.This technology also in line
with progress in our world now.Comfortness is the evident when users use this technology while
drive a vehicle in the road.In addition, this technology is very easy ride in
the vehicle and can be distinguished with in the past . We can conclude
technology influence every aspect of technology to human life,no matter in
automobile sector or other sectors.
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