Definition
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 apply the break and everything are 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. Initializing 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. Most of these accidents are fatal. The victims of such accidents are either severly injured, some even risk their life by their careless driving. This was the main reason behind this project work put forward by the Delphi-Delco electronic systems and General Motors Corporation. It was called the Automotive Collision Avoidance Systems (ACAS) field operation program.

ACAS
It was aimed at integration of the latest technology Forward Collision Warning (FCW) and Adaptive Cruise Control (ACC). The project has two phases. The Phase I started by June 1999, it lasted for about 27 months and II phase started immediately just after the Phase I and expected to be complete by 32 months.
The phase I include development and integration of ACC and FCW systems on the automotive. The phase II include the deployment fleet on ten cars and field operation test.

FCW
Forward Collision Warning (FCW) System was one of the achievements of the Delphi-Delco Electronic Systems, which was successfully implemented in the (a) 1994 Toyota Lexus LS400 (b) 1994 GM Cadillac Seville, and © 1998 Opel Vectra. These vehicles have been modified to provide the basic functionality of fully integrated ACC and FCW systems. Forewarn Smart Cruise Control with Headway Alert uses a mechanically scanning, 76 GHz, long-range radar sensor to detect objects in the vehicle's path up to 150 meters or 402 feet ahead. The system helps to reduce the need for drivers to manually adjust speed or disengage cruise control when encountering slower traffic.

ACC
Adaptive Cruise Control (ACC) and Forward Collision Warning (FCW) systems require an ability to resolve and identify robustly the existence of both stationary and moving 'target' vehicles that are in the motion path of the Host vehicle. The performance of these systems is affected by their ability (a) to estimate the relative inter-vehicular path motion (i.e.: range, relative speed, radius of curvature, etc.) between the host vehicle, the roadway ahead of the host, and all of the appropriate targets (i.e.: roadside objects, and in-lane, adjacent lane, and crossing vehicles, etc.); and (b) to predict the mutual intersection of these motion paths. In addition, these systems must be robust in the presence of various types of driving behavior (e.g.: in-lane weaving/drift, lane change maneuvers, etc.) and roadway conditions (e.g. straight roads, curved roads, curve entry/exit transitions, intersections, etc.) that are encountered in the 'real-world' environment.

The target selection approach pursued used a single active forward looking radar sensor augmented with a yaw rate sensor. The forward-looking radar sensor provided target range, range rate, and angular position information. The yaw rate sensor was used to estimate the roadway curvature ahead of the Host vehicle. Delphi's first generation target discrimination algorithms were used to identify overhead bridge objects and to discriminate between moving cars and trucks. The Target / Host kinematics were evaluated to determine target motion status (i.e.: oncoming, stopped, moving, cut-in and cut-out, etc.), and geometric relationships were employed to determine which of the valid roadway objects fell within the Host's forward projected path. The improved algorithms yielded very good results, but they were prone to false alarms during curve entry/exit scenarios and during host lane changes.