SUPPLEMENTAL NISSAN NEWS From: Corporate Communications Department
A30-SN-8092 Date: December 2, 1998

Nissan Develops "ITS CAR 2001-c" Concept Car Incorporating

ITS Vehicle Control Technologies

Tokyo ‐ Nissan Motor Co., Ltd. today announced the development of the "ITS CAR 2001-c" concept car incorporating an array of cutting-edge Intelligent Transport System (ITS) technologies that are being developed to translate ITS into a practical reality. This concept car represents Nissan's proposals for advanced vehicle control systems in the 21st century. It embodies a host of technical innovations in essential vehicle capabilities for "going, cornering and stopping" as well as in the human-machine interface linking the
driver and the car.

Nissan's ITS CAR 2001-c concept car is aimed at compensating for careless human error and at reducing the driver's workload so as to provide greater driving comfort and enjoyment. This is accomplished by supporting the driver in all areas of going, cornering and stopping performance through vehicle control technologies that make extensive use of sophisticated sensing techniques for recognizing the driving environment.

In the area of "going" performance, the car adopts an adaptive cruise control (ACC) system with braking capability and a stop-and-go system for following a preceding vehicle in congested traffic. The combination of these two systems makes it possible for the concept car to follow a preceding vehicle in all driving speed ranges. With regard to "cornering" performance, it adopts a lane-keeping system that automatically steers the vehicle. The integration of these three systems achieves ACC with two-directional control for automatically controlling the longitudinal and lateral movement of the vehicle simultaneously. In the area of "stopping" performance, the concept car adopts a preview braking system, representing an automated braking assist system capable of recognizing the driving environment.

The ITS CAR 2001-c also provides vehicle control performance in line with people's actual driving behavior and wishes, based on the results of driver behavior analyses conducted with a driving simulator. Besides integrating various vehicle control systems, Nissan aims to achieve systems that are easy to understand and feel completely natural to drivers. These analyses have also been used to incorporate innovations in the human-machine interface, including driving control features that are not annoying to drivers and driving mode displays that are simple for drivers to understand. The driving simulator is capable of calculating vehicle motions in real time based on a driver's steering maneuvers and pedal operations. The resulting data are used to create images which correspond to vehicle motions and are displayed on a forward screen. This makes it possible to simulate on a dynamometer the sensations of vehicle motions and the experience of driving.

Nissan envisions a four-stage process of evolution for vehicle control systems. Present control systems represent the first generation, and those incorporated in the ITS CAR 2001-c concept car are positioned as second-generation technologies. Both generations are autonomous systems which do not use the road infrastructure. In the future, third-generation vehicle control systems will appear which will also be able to operate in cooperation with the road infrastructure, such as through the use of information on road surface conditions or the vehicle position. It is projected that fourth-generation systems will facilitate automated driving as a result of further advances in vehicle control technologies.

In August, Nissan also announced the development of the ITS CAR 2001-i concept car incorporating various ITS technologies for providing information to drivers. These information technologies and vehicle control technologies are expected to merge in the coming years. Nissan intends to push ahead vigorously with R&D activities in line with a future vision of ITS in which information, vehicle control and infrastructure are harmonized in totally integrated systems.

Typical Vehicle Control Systems Incorporated in ITS CAR 2001-c
Adaptive cruise control system

Objectives	To reduce driver fatigue and also achieve driving behavior coordinated with the flow of traffic.
Technical overview	A millimeter-wave radar measures the distance from the host vehicle to a preceding vehicle and the relative vehicle velocity. The system controls the throttle and brakes so as to automatically maintain a set headway distance corresponding to the driving speed.

Stop-and-go system for following a preceding vehicle in congested traffic

Objectives

To reduce the annoyance of constantly starting and stopping in congested traffic. To reduce rear-end collisions due to careless error in congested traffic.

Technical overview

The system measures the distance to a preceding vehicle in congested traffic and automatically accelerates or decelerates the host vehicle to maintain the headway distance set by the driver. If the preceding vehicle stops, the host vehicle also stops at the specified distance from it. When the preceding vehicle starts off, the driver is advised by a buzzer and can resume travel by inputting a start-off command.

Lane-keeping system

Objectives	To reduce accidents that occur when inattentive drivers stray from their lane. To reduce fatigue caused by driving operations.
Technical overview	The system helps keeping the host vehicle in its lane when traveling on an expressway or an automated highway system by using a CCD camera to recognize white lines on the road surface.

Preview braking system

Objective

To reduce collision speeds in emergency braking situations.

Technical overview

The system measures the distance to a preceding vehicle and applies pre-brake pressure when it estimates that quick deceleration is needed because of the host vehicle's high speed. This quickens the brake response, shortening the distance before the brakes take effect. It can reduce the collision speed by 5 km/hr in a typical case often seen in rear-end collisions. In this case, a driver traveling at a speed of 50 km/h becomes aware of an emergency situation 20 meters ahead.

Conceptual Diagram of Control Systems on ITS CAR 2001-c

Contact: Foreign Media Section 03-5565-2147