ABSTRACT
This seminar paper is based upon the
project work being carried out by the collaboration of Delphi-Delco Electronics
(DDE) and General Motors Corporation. It was named the Automotive Collision
Avoidance Systems (ACAS) field operation program to build the tomorrow’s car.
It used latest technologies of radar sensing to prevent collision. Video
imaging to track its path, and uses DGPS for locating the position of the
vehicle on the road. It completely utilized the latest technologies in Robotics
as obstacle sensing, tracking and identification.
INTRODUCTION
All of us would like to drive our car with a
mobile held in one hand, talking to the other person. But we should be careful;
we don’t know when the car just before us applies the break and everything is
gone. A serious problem encountered in
most of the cities, National Highways, where any mistake means no ‘turning back’!
There comes the tomorrows technology; Hand free driven car. Utilizing the modern
technological approach in Robotics.
What is the need for
safety precaution?
All around the world almost 45% of the accidents occur
by mistakes of the driver. In some cases the driver is engaged in some other
affair than driving. In USA
ACAS
It is the Automotive
Collision Avoidance System (ACAS). The ACAS/FOT Program has assembled a highly
focused technical activity with the goal of developing a comprehensive FCW
system that is seamlessly integrated into the vehicle infrastructure.. The FCW system
incorporates the combined ACC & rear-ends CW functionality. The ACC feature
will only be operational when engaged by the driver. On the other hand, the FCW
feature will provide full-time operating functionality whenever the host
vehicle is in use (above a certain min speed). This feature is effective in
detecting, assessing, and alerting the driver of potential hazard conditions
associated with rear-end crash events in the forward region of the host vehicle.
This is accomplished by implementing an expandable system architecture that
uses a combination of: (a) a long range forward radar-based sensor that is
capable of detecting and tracking vehicular traffic, and (b) a forward
vision-based sensor which detects and tracks lanes. The proposed program effort
is focused on providing warnings to the driver, rather than taking active
control of the vehicle.
Due to the
complexity and breadth of the system goals, the on-going design process has
heavily relied on using the established principles of system engineering as a
framework to guide this highly focused deployment design effort. As such, the
technical activities of the program can be grouped into four main activities
within two phases. Phase I started immediately after program inception in, June
1999, and lasted approximately 27 months. Phase II started immediately after
the end of Phase I. The objective was that the two program phases will be
continuous with minimal disruption of program flow and continuity between them.
Consequently, activities that enable the continuous workflow into Phase II will
be initiated during Phase I. The program phases are summarized as:
Phase
I
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1.
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Development -
The program initially focused on a variety of activities associated with the
enhancement, improvement, and maturation processes applied to existing FCW
technologies/components that were developed during the ACAS Program, while
accelerating the development of other key subsystems,
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2.
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Integration -
The refined FCW portfolio of technologies/components was upwardly integrated
into the vehicle platform infrastructure to form a comprehensive rear-end
collision warning system,
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Phase II
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3.
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Deployment
Fleet - The validated design was used to build a deployment fleet of ten
vehicles equipped with the system; and
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4.
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Field
Operational Test - The culmination of this program activity will be the
design and implementation of the FOT plan. The deployment vehicle fleet will
be used to collect valuable market research data in order to assess/validate
the technology, product maturity, and general public perception.
The FOT is the natural
next step of the technology development cycle that was initiated with the
Automotive Collision Avoidance System (ACAS) Development Program. This program
was sponsored through the Technology Reinvestment Project (TRP) and
administered by the National Highway Traffic Safety Administration (NHTSA)
between January 1995 and October 1997. Delphi-Delco Electronics Systems (DDE)
and General Motors (GM) were major participants of the eight-member ACAS
Consortium. Additionally, DDE led the ACAS Consortium. The primary objective
of the ACAS Program was to accelerate the commercial availability of key
collision warning countermeasure technologies, through either improved
manufacturing processes or accelerated technology development activities. The
next logical technical progression of the product development cycle was the
upward integration of these ACAS-developed essential building blocks to form
a complete seamless vehicle system that will be evaluated through a field
operational test program. It is apparent that the introduction of Adaptive Cruise Control (ACC)
systems is imminent. Therefore, posing the notion of a field operational test
of the collision warning technology at this time is apropos. An extensive,
comprehensive collision warning FOT has never been undertaken in the
In support of achieving a
successful field operational test, the ACAS/FOT Program had assembled a
highly focused technical activity with the goal of developing a comprehensive
FCW system that was seamlessly integrated into the vehicle infrastructure.
The performance of the cohesive collision warning vehicle package will be of
sufficient fidelity, robustness, and maturity so that a meaningful field
operational test program can be executed. The FCW system will incorporate the
combined ACC & rear-end CW functionality. The ACC feature will only be
operational when engaged by the driver. On the other hand, the FCW feature
will provide full-time operating functionality whenever the host vehicle is
in use (above a certain minimum speed). This feature will be effective in
detecting, assessing, and alerting the driver of potential hazard conditions
associated with rear-end crash events in the forward region of the host
vehicle.
ACC
It is the Adaptive Cruise
Control system. In the current ACAS
FOT program, four complementary host and road state estimation approaches are
being developed. The complementary approaches are as follows:
(a) vision
based road prediction
(b) GPS based road prediction
(c) radar based scene tracking
(d) yaw rate based road and host state estimation
These four roads and host state estimation approaches are being
correlated and fused by the Data Fusion system and provided parametrically to
the Tracking and Identification Task. The fused road and host state
information provides an improved estimate of the roadway shape/geometry in
the region ahead of the Host vehicle, and an improved estimate of the Host
vehicle’s lateral position and heading within its own lane. This information
is being incorporated into the Tracking and Identification functions to
provide more robust roadside object discrimination and improved performance
at long range, during lane change maneuvers, and during road transitions. In
addition, a new radar-based roadside object discrimination algorithm is also
being developed to cluster and group roadside stationary objects, and the
first generation truck discrimination algorithms developed during the
previous ACAS program are being enhanced. Furthermore, a new yaw rate based
host lane change detection algorithm is also being developed.
GPS(GLOBAL POSITIONING SATELLITE) SYSTEM
The most important part of
the ACC system is the Digitized GPS .Global
Positioning Satellite Systems (GPS) are navigation tools which allow users to
determine their location anywhere in the world at any time of the day. GPS
systems use a network of 24 satellites to establish the position of
individual users. Originally developed by the military, GPS is now widely
utilized by commercial users and private citizens. GPS was originally
designed to aid in navigation across large spaces or through unfamiliar
territory. As a tool for law enforcement, GPS can assist agencies by
increasing officer safety and efficiency.
The
United States Coast Guard defines GPS as "a satellite-based
radio-navigation system." In lay person terms, GPS operates when a
network of satellites "read" the signal sent by a user’s unit
(which emits a radio signal). A GPS unit receives data transmitted from
satellites— at least three satellite data inputs are necessary for accurate
measurements.
The
unit then interprets the data providing information on longitude, latitude,
and altitude. GPS satellites also transmit time to the hundredth of a second
as coordinated with the atomic clock. With these parameters of data and
constant reception of GPS signals, the GPS unit can also provide information
on velocity, bearing, direction, and track of movement.
GPS
receivers can be integrated with other systems, such as a transponder or
transmitter. The transmitter takes information from the GPS receiver and
transmits it to a defined station, such as a police dispatcher. The
dispatcher must have the system to both receive the transmission in
"real time" along with the GPS data. To be truly useful, this
information must be integrated with a Geographic Information System (GIS)
which has a map of the community and translates the longitude and latitude
into addresses.
Brake Control System
A new Delphi Brake Control System
will replace the OEM brake components on the Prototype and FOT deployment
vehicles. The brake control system includes an anti-lock brake system (ABS),
vehicle stability enhancement, and traction control features. For this
program, the brake system will be enhanced to respond to ACC braking commands
while maintaining the braking features and functions that were in the
original brake system.
Over the past two years, the DBC 7.2 brake control system has undergone
significant testing for production programs. During the first year of the
ACAS/FOT program, the brake system was integrated on a chassis mule and one
of the Engineering Development Vehicles. Calibration and tuning of the brake
system has started.
Throttle Control System
The throttle control system
maintains the vehicle speed in response to the speed set by the driver or in
response to the speed requested by the ACC function. The
The information from the ACC
controller and the ACC radar sub-system is fed to the processor through the
CAN bus which has the data rate of 500kbps. The ACC controller controls the
throttle and brake actuators to have effective brake and throttle control.
The primary ACC Subsystem display will be in a head-up display. The
primary ACC display will include the following information:
The vehicle will provide a forward collision warning capability that
will provide alerts and advisory displays to assist drivers in avoiding or
reducing the severity of crashes involving the equipped vehicle striking the
rear-end of another motor vehicle. For the purposes of the FOT, the FCW will
have enabled and disabled modes. The FCW will be enabled and disabled when
conditions specified by the ACAS/FOT engineers are met using the same
mechanism that enables and disables the adaptive capability of the cruise
control. The driver will not be able to disable the FCW, but the driver will
be provided with a control to adjust the sensitivity (alert range) of the FCW
function. The sensitivity adjustment will not permit the FCW function to be
disabled by the vehicle operator.
m
Benefits
Ø Conveniently manages vehicle
speed and headway gap
Ø Complements vehicle styling
Ø Makes cruise control more
useable in most traffic
conditions resulting in a more relaxed
driving experience
Ø Operates under wide range of
environmental conditions
(dirt, ice, day, night, rain, or fog)
Ø Low false alarm rate
Features
Ø Radar-based sensing for
optimal performance
Ø Sensor hidden behind front
grille or fascia
Ø Best available detection and
tracking performance
Ø Manages vehicle speed and
headway gap using throttle
control and limited braking
Ø Automatically notifies
driver of a blocked sensor via
displayed message
Ø Excellent following distance
and speed control
CONCLUSION
Robotics is the part of electronics
engineering, which exploits each aspect of electronics and mechanical
engineering. The developments of robotics have lead to the ACAS program. On
the completion of this program vehicles will change the phase of driving; a handfree
driving.
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