Delphi Announces Electrical - Not Mechanical - Components for Steering, Braking, Throttle & Suspension Control
23 February 1998
Delphi Drive-By-Wire Technologies, 'X-By-Wire,' Turn to Electrical - Not Mechanical - Components for Steering, Braking, Throttle & Suspension Control
TROY, Mich., Feb. 23 -- Ultra high-tech vehicles of the 21st
Century won't have to rely on mechanical components for braking, steering,
throttle, and suspension controls. Instead, all those systems can function
electronically through Delphi Automotive Systems new drive-by-wire system,
"X-By-Wire," shown in Detroit today at the 1998 SAE International Congress and
Exposition.
With "X-By-Wire," steering, braking, throttle and other vehicle functions
are performed without the traditional steering column, steering shaft, rack &
pinion gear, brake booster, master cylinder, hydraulic lines, throttle cable
and linkages. Instead, each system is connected by wires that form a pathway
to communicate information from sensors positioned throughout the vehicle to
an electronic control module. This control module then provides input to a
system's actuator that performs the mechanical function of the system.
This unique approach significantly reduces the amount of mechanical
components required in the vehicle and greatly enhances vehicle performance.
Delphi's "X-By-Wire" is being developed by the company's Saginaw Steering,
Chassis, Energy & Engine Management, and Delco Electronics systems divisions.
The systems which make up "X-By-Wire" include:
Brake-By-Wire. The technology behind Delphi's Galileo(TM) braking system
and the world's first production Brake-By-Wire system. Galileo is a family of
intelligent brake control systems that provide brake power assist, ABS,
traction control, vehicle stability enhancement control, regenerative brake
blending control, automated braking, and tunable pedal feel in a single,
modular system.
Throttle-By-Wire. This consists of a pedal module containing sensors that
relay driver acceleration intent information to engine electronic controls,
while also supplying force feedback to the driver. The Engine Management
System then determines and positions the air valve in the appropriate position
through the use of a motor. It also synchronizes air, fuel and dilution
control to improve engine performance and emissions.
Damper-By-Wire. This system features four electronically controllable
dampers (shocks or struts), a steering sensor, and four ride motion sensors.
The sensor information is passed to the electronic control module that
analyzes the vehicle's dynamic conditions and determines the optimum damping
level to command from the dampers. These adjustments are rapid for real-time
control of vehicle ride and handling.
Roll-By-Wire. This system provides real-time roll stiffness control at
the front and rear of the vehicle. Actuators are added to stabilizer bars to
allow active or semi-active control of roll stiffness. This system allows for
reduced head toss and improved wheel articulation in addition to reduced roll
angle.
Front Steer-By-Wire. This system eliminates the mechanical connection
between the driver and the front wheels of the vehicle. With Front Steer-By-
Wire, the traditional steering column, steering shaft and steering gear are
replaced by two actuators positioned in the vehicle's front corners. These
actuators receive input from the control module and turn the front wheels
accordingly. The system also uses an electric motor to provide road feedback
to the driver's handwheel. The operation of the system is transparent to the
driver since a handwheel is still used -- however, future models of this
technology could employ a joystick instead of a traditional steering wheel.
Rear Steer-By-Wire. The technology behind Delphi's Four Wheel Steering
system, this electrical rear steering system uses sensors to position the back
wheels based on front wheel position and vehicle speed. It provides a tighter
turning radius, increases vehicle stability and enhances trailering.
Traxxar(TM). Traxxar is a vehicle stability enhancement system that uses
an extra set of sensors integrated with ABS and Traction Control to apply
individual wheel brake intervention to assist the driver in reducing the
difference between the driver's requested direction and the actual vehicle
direction. Traxxar improves vehicle stability and directional control at the
limit of adhesion over a variety of road conditions.
Delphi's "X-By-Wire" system offers many benefits to OEMs. For instance,
the reduction in hardware requirements for these systems provides vehicle
designers with increased packaging flexibility. In fact, some of the
traditional mechanical componentry is actually eliminated, as with Front
Steer-By-Wire, thereby freeing up space under the hood and reducing vehicle
mass. System modularity simplifies vehicle assembly and reduces labor and
inventory costs.
"X-By-Wire" also enhances the environmental friendliness of vehicle
operation. For example, Throttle-By-Wire reduces engine emissions by
controlling the air and fuel mixture that goes into the engine, especially
under transient conditions, allowing less waste to leave the vehicle as
exhaust and optimizing fuel consumption. Some fuel economy can also be gained
from regenerative braking with the Brake-By-Wire system. Another
environmental attribute of "X-By-Wire" is the electronically controlled
braking and steering systems that eliminate the use and disposal of
traditional hydraulic fluids.
Beyond the appeal to OEMs, the integration of "X-By-Wire" systems
translates into enhanced overall vehicle performance for the consumer. These
"smart" systems are constantly monitoring road conditions, driver input and
vehicle function. These activities are transparent to the driver yet provide
improved ride and handling, fuel economy and safety.
The technology used in Delphi's "X-By-Wire" systems also is being
integrated with collision warning system technology to enable complete
collision avoidance vehicle control. This type of technology was recently
demonstrated on an automated highway system in California.
Delphi Automotive Systems, with headquarters in Troy, Mich., USA, is the
world's most diversified supplier of automotive components and systems. With
the recent integration of Delphi Delco Electronics Systems, Delphi operates
208 manufacturing facilities, 46 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.
"NEXT CENTURY WINNERS" FACT SHEET
"X-BY-WIRE"
NEWS
Delphi develops futuristic drive-by-wire technologies for steering,
braking, throttle and suspension control -- collectively marketed as "X-By-
Wire."
OPERATION
Highlighted "X-By-Wire" technologies include:
Brake-By-Wire
* The world's first production Brake-By-Wire system is Galileo(TM), a
family of intelligent brake control systems that provide brake power
assist, ABS, traction control, vehicle stability enhancement control,
regenerative brake blending control, automated braking, and tunable
pedal feel in a single, modular system.
Throttle-By-Wire
* Consists of a pedal module containing sensors that relay driver
acceleration-intent information to the engine management system, while
also supplying force feedback to the driver.
* The engine management system then determines and positions the air
valve in the appropriate position through the use of a motor.
Damper-By-Wire
* Features four electronically controllable dampers (shocks or struts), a
steering sensor, and four ride motion sensors.
* The sensor information is passed to the electronic control module,
which analyzes the vehicle's dynamic conditions and determines the
optimum damping level to command from the dampers.
Roll-By-Wire
* Provides real-time roll stiffness control at the front and rear of the
vehicle.
* Actuators are added to stabilizer bars to allow active or semi-active
control of the roll stiffness.
* This system allows for reduced head toss and improved wheel
articulation in addition to reduced roll angle.
Front Steer-By-Wire
* Eliminates the mechanical connection between the driver and the front
tires of the vehicle.
* The traditional steering column, shaft and gear are replaced by two
actuators positioned in the vehicle's front corners. These actuators
receive input from the control module and turn the front wheels
accordingly.
Rear Steer-By-Wire
* This is an electrical rear steering system that uses sensors to
position the back wheels based on front-wheel position and vehicle
speed.
* It provides a tighter turning radius, increases vehicle stability and
enhances trailering.
Traxxar(TM)
* Vehicle stability enhancement system uses an extra set of sensors
integrated with ABS and Traction Control to apply individual wheel
brake intervention, assisting the driver in reducing the difference
between the driver's requested direction and the actual vehicle
direction.
BENEFITS
* Eliminates hardware, reducing mass and increasing packaging
flexibility.
* Modularity simplifies vehicle assembly and reduces labor and inventory
costs.
* Enhances environmental responsiveness by reducing engine emissions,
improving fuel economy, and eliminating hydraulic fluids.
SOURCE Delphi Automotive Systems