Delphi Introduces MagneRide Suspension Control Technology
15 September 1999
Delphi Introduces MagneRide(TM) Suspension Control Technology at 1999 IAA
FRANKFURT, Germany, Sept. 14 -- Delphi Automotive Systems
today unveiled its new MagneRide(TM) suspension control
technology, the industry's most advanced variable damping system and one of
the links to complete vehicle chassis integration, according to the engineers
who helped develop it.
The MagneRide system -- introduced here at the Frankfurt International
Motor Show (IAA '99) -- is a high-performance, high-value, semi-active
suspension control system that optimizes vehicle ride and handling by
providing Continuously Variable Real-Time Damping (CV-RTD) control based on
road and driver inputs.
"Up until now, there has not been a variable damping system that performs
as quickly as MagneRide, or one that has enough authority and could be
electronically linked to a vehicle's stability control system," said Dr. Alex
Alexandridis, Delphi Chassis Systems' director of Advanced Engineering for
Europe.
"It's also a high-value, cost-effective system thanks to innovations in
the MR fluids, actuators, and algorithms."
Alexandridis, who led the MagneRide development team, said the system
revolutionizes Continuously Variable Real Time Damping (CVRTD) suspension
technology through use of innovative, Delphi-developed Magneto-rheological
(MR) fluid and valve-less, monotube struts and shock absorbers.
"MagneRide is the first commercially available system that takes full
advantage of the controllable rheology of MR fluids and delivers valve-less
damping control," Alexandridis said. "The results are world-class ride and
handling performance from a very simple, reliable, and quiet system.
"As a stand-alone system, MagneRide offers customers a substantial
improvement in ride quality, vehicle handling and stability," he said. "But
the true impact of MagneRide is felt when it is linked with other chassis
control systems in order to provide the ultimate in vehicle stability control
and active safety."
Highlights of the MagneRide system include:
* Revolutionary Performance -- MagneRide brings variable damping to
high-performance levels currently unmatched in the industry. It helps
overcome the traditional tradeoffs between ride and handling by delivering
increased maximum damping forces with lightning-quick response. It also
delivers ultra-quiet operation in a durable, cost-effective package (see
related release: "Delphi's MagneRide Achieves World-Class Performance .... ");
* Magneto-rheological Fluid -- MagneRide represents the industry's first
commercially available application of MR fluid in a variable damping system.
The fluid enables valve-less dampers and damping level adjustments of up to
1000 times per second. (see related release: "Delphi-Developed Magneto-
Rheological Fluid Enables Next Level .... "); and,
* Unified Chassis Control -- MagneRide is the industry's first valveless
variable damping system that can be electronically linked with other vehicle
chassis controls (see related release: MagneRide's High Speed, Advanced
Capabilities Linked to Unified Chassis Control .....)
DELPHI-DEVELOPED MAGNETO-RHEOLOGICAL FLUID
ENABLES NEXT LEVEL OF VARIABLE DAMPING PERFORMANCE
FRANKFURT -- The use of magneto-rheological (MR) fluid in Delphi
Automotive Systems' new MagneRide(TM) suspension control
technology is not only an industry first, but an enabler to achieving the next
level of variable damping performance.
According to Delphi engineers, the application of MR fluids enables
lightning-quick response and a valve-less damper design, resulting in
never-before-seen levels of performance, virtually silent operation, and the
elimination of electromechanical valves.
In operation, the MagneRide system's electronic control unit continually
sends electrical currents to electromagnetic coils housed in the dampers. The
currents dictate the MR fluids' yield stress, which in turn determines damping
resistance.
MR fluids are produced by suspending magnetically soft particles in a
synthetic hydrocarbon or silicon base fluid. Such fluids are nothing new, but
their application to commercial variable damping systems are, according to
Bill Cornwell, Global Planning Team leader for Intelligent Chassis Controls.
"We are a pioneer in the development of MR fluids for use in damping
systems, but there are other formulations of the fluids which are used for
entirely different applications, such as exercise equipment," Cornwell said.
"What we've developed is a custom-designed fluid for a shock absorber
application that's used on the MagneRide system.
"That means it won't settle out, evaporate, wear down, or be too abrasive
on the damper material that it comes in contact with."
The Delphi-developed MR fluid used in the MagneRide system dampers
features a "bimodal" particle size distribution that incorporates two sizes of
iron microspheres -- large and small -- that are distributed in optimized
proportions.
This combination produces a fluid with the high yield stress and low
viscosity required for damper applications, according to Dr. Alex
Alexandridis, Delphi Chassis' director of Advanced Engineering for Europe and
leader of the team that developed MagneRide.
"Our design optimization studies showed that, for damper applications, MR
fluid should be very thin when no magnetic force is applied, but produce a
high MR effect in a magnetized state," Alexandridis said.
"Our MR fluid does just that -- the applied magnetic field aligns the
metal particles into fibrous structures, controlling the fluid's yield stress
without affecting its viscosity," he said.
"The MR fluid reacts to an external magnetic field in less than
1 millisecond. The MR effect is reversible and not affected by high
temperatures."
Alexandridis said the fluid -- when coupled with MagneRide's high
performance actuation and a unique control algorithm -- delivers "the best
performance we've ever seen in a controlled suspension system.
"It takes suspension control technology to the next level."
DELPHI'S MAGNERIDE(TM) ACHIEVES WORLD-CLASS PERFORMANCE
IN COST-EFFECTIVE SYSTEM USING UNIQUE VALVELESS DAMPING
FRANKFURT -- MagneRide(TM), the sophisticated suspension control system
developed by Delphi Automotive Systems , achieves world-class
performance in a cost-effective package with the first commercial use of
valve-less damping and Magneto-rheological (MR) fluid.
The semi-active system -- the first based on fully integrated algorithm
control -- responds virtually instantaneously and silently to road and driver
inputs. It helps overcome the traditional tradeoffs between ride and handling
because of the magnitude of force it can apply over a broad range of damper
velocities for superior control on even the roughest road surfaces.
At the other end of the scale, it can minimize damping forces as needed
for improved road isolation and ride smoothness, according to Dr. Alex
Alexandridis, leader of the MagneRide development team and Delphi Chassis'
director of Advanced Engineering for Europe.
Bill Cornwell, Global Planning Team leader for Intelligent Chassis
Controls, said the system will first appear on a production vehicle in model
year 2003. It is being introduced here today at the 1999 Frankfurt
International Motor Show.
The system has been demonstrated on a variety of different types of
vehicles, ranging from a high-performance sports car to sport utility vehicles
and passenger cars.
In each case, the system has demonstrated exceptional ability to:
* Increase control of vehicle motions for a flat ride and precise
handling
* Enhance road holding for improved wheel control and a safer, more
secure ride
* Control load transfer characteristics for improved roll control and
handling during sudden, high-speed maneuvers
* Improve road isolation by reducing the transmission of high-frequency
road disturbances through the dampers
Alexandridis said three enabling technologies made the development of
MagneRide possible:
* The MR fluid
* The damping actuator
* The control algorithm
The damping actuators are innovative struts or shock absorbers which are
gas-charged, monotube designs without valves or any other small moving parts.
They were designed and developed by Delphi. Current applied to an
electromagnetic coil inside the damper's piston controls the flow of the
custom-designed MR fluid in the damper.
"This produces a mechanically simple, but very responsive, controllable
damping action," said Alexandridis, "providing a flatter ride during cornering
and reduced 'dive' and 'squat' during braking and accelerating than a passive
suspension system."
It can achieve a much broader damping range and respond much more rapidly
than valve-based systems without generating noise, he said. "Valve-based
systems can be configured for greater damping capability but they become
noisier as a result and can't approach the speed of the MagneRide system."
The valve-less dampers provide a smooth, laminar flow of the MR fluid that
is very quiet, unlike valve-based systems that are prone to noisy, turbulent
flows in the dampers, Alexandridis said.
"With MagneRide, you don't have that 'loose lumber' noise effect, like a
board bouncing around in the trunk, that you get with conventional valve-based
continuously variable real-time damping (CVRTD) systems," he said.
And because of the predictable performance of the laminar flow, the
mechanical characteristics of the damper can be designed and controlled to
accurately meet design specifications, Alexandridis said. "We can build the
system to come within 2 percent or 3 percent of design specifications, which
is a breakthrough in damper design," he said.
The dampers developed for MagneRide can change damping levels as much as
1000 times per second with no lag, if required, and they are extremely stable
and insensitive to cavitation or contamination, Alexandridis said.
The monotube dampers also add to the system's quality and performance
since they're pressurized, they don't lag or fade, and they have excellent
heat dissipation ability, he said.
"The system provides continuously variable damping that outperforms
conventional CVRTD systems, but without the electro-mechanical valves used in
those systems," Alexandridis said.
Several costly sensors required by other manufacturers' semi-active
suspension control systems have been eliminated in MagneRide, he said.
MagneRide uses a cost-effective, simplified sensor set consisting of a
displacement sensor at each vehicle corner, a lateral accelerometer and a
steering hand-wheel displacement sensor.
These sensors determine absolute velocities of the body heave, roll and
pitch motions. The algorithm and ECU use this input to control the
distribution of the normal load through the tire patches by varying the level
of damping at each corner of the vehicle depending on the conditions of the
vehicle's motion, as well as driver inputs (e.g., steering and braking),
Alexandridis said.
MAGNERIDE'S HIGH SPEED, ADVANCED CAPABILITIES
LINKED TO UNIFIED CHASSIS CONTROLS
FRANKFURT -- The extremely high response speed of Delphi Automotive
Systems new MagneRide(TM) suspension control system -- the fastest
on the market -- and the ability to easily manage roll forces, even during
extreme handling maneuvers, is one of the missing links in developing a
complete Unified Chassis Control system.
With MagneRide, Delphi engineers are doing just that -- electronically
linking the braking, suspension, steering and powertrain chassis sub-systems
so they all work in concert to give motorists the best possible control of
their vehicle under all conceivable driving conditions.
"With Delphi Unified Chassis Controls, we will be able to provide vehicles
with greatly improved balance, handling and the highest reserve of tire
grip -- and all at reduced cost, space, weight and complexity," said Bill
Cornwell, leader of Delphi Chassis' Global Planning Team on Intelligent
Chassis Controls.
This next-generation chassis control concept has already been successfully
demonstrated on both luxury passenger cars and high-performance sports cars.
MagneRide adds an ingredient because it provides the level of variable
damping performance in the suspension system demanded in a fully unified
chassis control system, Cornwell said.
"The real value of MagneRide is in its potential for realizing this system
unification to give motorists unparalleled levels of control, confidence and
safety," he said.
"This is the first automotive application of a high-authority, rapid
response actuator with this level of sophistication," he said. "In fact,
we're still learning about the potential chassis control opportunities such an
advanced variable damping system offers.
"We do know two things already: It provides a tremendous improvement in
ride and handling for the customer, and it can be linked to stability control
systems to give them even greater capability," he said.
Dr. Alex Alexandridis, Delphi Chassis' director of Advanced Engineering
for Europe, said of MagneRide, "By linking the variable damping system with
the braking system, ride can be adjusted during braking for better control,
especially on rough roads, based on information from the suspension," he said.
"By sharing sensors among the major chassis subsystems we avoid duplication,
reduce cost and increase overall system reliability," he said.
MagneRide also is fully compatible with Delphi's TRAXXAR(R), other
electronic stability program (ESP) systems and roll control systems like
Delphi's new Dynamic Body Control(TM), Alexandridis said.
"TRAXXAR and other ESP systems use individual wheel brakes differentially
to help stabilize the vehicle and help the driver maintain control during
sudden maneuvers," he said.
"When MagneRide is linked to these chassis control systems, the controlled
suspension can adjust the wheel and body damping characteristics of the
suspension at the very onset of a maneuver, providing excellent stability
throughout. MagneRide in effect controls the lateral and longitudinal load
transfer characteristics of the vehicle during transients and contributes to
the overall stability and response of the vehicle. This way, the ESP system
does not have to apply as much braking, which could surprise the driver and
cause energy losses as the vehicle slows," he said.
Delphi Automotive Systems , with headquarters in Troy, Mich.,
USA, is a world leader in automotive component and systems technology.
Delphi's three business sectors -- Dynamics & Propulsion; Safety, Thermal &
Electrical Architecture; and Electronics & Mobile Communications -- provide
comprehensive product solutions to complex customer needs. Delphi has more
than 200,000 employees and operates 169 wholly owned manufacturing sites, 40
joint ventures and 27 technical centers in 36 countries. Regional
headquarters are located in Paris, Tokyo, and Sao Paulo. Delphi can be found
on the Internet at http://www.delphiauto.com .