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The objective of this study is to develop a neuro controlled active suspension for the ride quality improvement. The performance index of the optimal control is represented as the frequency-shaped using Parseval's theorem. The incorporation of frequency-dependent weighting matrices allow one to emphasize the specific variables related to the vibrations of the specific bands of frequencies. Once the active control law is obtained, we use the artificial neural networks to train the neuro controller to learn the relation of road input and control force. From the numerical results, we found that back propagation learning does good pattern matching and the neuro controlled suspension may reduce the vertical acceleration of the driver's seat and sprung mass motions significantly at desired bands of frequencies.

The role of sensors and sensing technologies for the next generation vehicle systems are discussed. The control systems for engines and power-train are expected to realize high efficiency with low pollution and comfort drivability. Vehicular safety and chassis control systems are expected to avoid many kinds of traffic accidents caused by the human errors of drivers. Vehicular information systems will help the drivers to get the information to manage their vehicles economically and efficiency. In every system mentioned above, sensors and sensing technologies are playing an increasingly important role. This paper introduces and discusses essential technologies for sensors and sensing which can be expected to bring the solutions to the future automotive systems.

An evaluation was conducted of a mechanical beam switching system that may be appropriate for use with HID lamps. Subjects rated the adequacy of beam change time at several rates, compared with an electrical beam changing system. The results indicate that the subjects rated the mechanical and electrical systems the same, at the shortest change time for the former. Longer change times elicited poorer ratings for the mechanical system. The change from low to high beam was rated better than the change from high to low beam in the mechanical system. This difference was statistically significant at the two slower change rates investigated.

The growing number of electronic components used in automobiles lately has given rise to problems concerning the increasing number, size and weight of the wiring harnesses. As one approach to resolving these problems, the authors proposed a multiplex method based on the direction of signal flow in 1988 (SAE880589). However, the need to reduce the number of wiring harnesses circuits further made it necessary to develop a more sophisticated system. This paper presents an on-board Class A local area network (LAN) system that overcomes the problems in conventional multiplexing systems through the use of a master-slave configuration, a polling selection method and a system that integrates of electronic circuits with switch modules.

Plastic optical fiber has been widely used in the field of short distance optical transmission. However heat resistance of commercial plastic fiber is so low that its applications are limited. Then, a plastic fiber of thermosetting acrylate resin core has been developed. This fiber shows 80%/m retention of light transmittance at 1m after 1,000 hours at 150°C. It resists heat deformation and withstands up to 200 °C for a short time period. Tests show this fiber has desirable mechanical characteristics, along with good environmental resistance. In addition, a fiber which has a silicon resin as a core material was developed which has even better heat resistance.

Mixture formation and the ignition process in 4 cycle 4 cylinder spark ignition engines were investigated, using an optical combustion sensor that combines fiber optics with a conventional spark plug. The sensor consists of a 1-mm diameter quartz glass optical fiber cable inserted through the center of a spark plug. The tip of the fiber is machined into a convex shape to provide a 120-degree view of the combustion chamber interior. Light emitted by the spark discharge between spark electrodes and the combustion flames in the cylinder is transmitted by the optical cable to an opto-electric transducer. As a result, the ignition and combustion process which depends on the mixture formation can be easily monitored without installing transparent pistons and cylinders. This sensor can give more accurate information on mixture formation in the cylinders.

This paper reviews the technological aspects and characteristics of optical fiber gyroscopes, and discusses their automotive applications. The optical system of an all-fiber gyroscope and the fiber optic components to build it are described. An optical phase modulation scheme to improve the sensitivity and the signal processing for the modulated output are discussed. The specifications of some packaged optical fiber gyroscopes are explained. An earth's rotation detection experiment is demonstrated to show the higher performance. The potential automotive related applications of the gyroscope are forecasted. One of the off-board uses of the sensor is the vibration measurements of a vehicle. When used onboard, the optical fiber gyroscopes will improve the navigation accuracy. A navigation result utilized the sensor with a map matching algorithm is reported. The gyroscopes may also be applied to future chassis controls.

Intelligent Vehicle-Highway Systems (IVHS) improve the operation of cars and trucks on public roads by combining information technology with road transportation technologies. The basic ideas about IVHS are by no means new but a number of converging forces have encouraged significant IVHS development in North America recently. Based on the results of a Delphi survey to project realistic future scenarios, both applied and fundamental research agenda are being formulated in a Michigan-based IVHS program to push the IVHS technologies for advanced motorist information systems and for backup vehicle controls under emergency conditions. The scope of the research agenda includes social/human elements as well as hardware and software technological systems. The Michigan research program is expected to contribute to the development of IVHS in North America, both technically and institutionally.

A multiplexed transmission system utilizing newly developed optical polymer has been proposed. The system is composed of a star-shaped optical network, in which optical signals can be transmitted bi-directionally through a fiber and optical branches between the central and local controllers. The new polymer optical fiber has been developed and adopted for this system, and it was designed to be durable to the high temperature in automotive engine rooms. The high temperature resistibility of the fiber has been achieved with utilization of a thermo-setting resin for the core materials. The optical loss characteristics of the fiber is as low as 0.50 dB/m at 660 nm wavelength.

The detection range of an air-fuel ratio sensor is expanded in the rich A/F region. Using a simulation technique, the limiting cause of the detection range in the rich A/F region is identified as insufficient combustion rates of CO and H2 with O2 on the electrode, which prevent realization of a limited diffusion state which is necessary to detect the air-fuel ratio. Applying an improved diffusion layer to decrease the diffusion rates and an improved electrode to increase the combustion rates, it is demonstrated that the detection limit can be expanded to λ=0.6 while that of a conventional sensor is λ=0.8.

A totally integrated vehicle electronic control system is described, which optimizes vehicle performance through use of electronics. The system implements efficient coordination of functions of the engine, drive-train, brakes, steering, and suspension control subsystems to give a smoother ride, better handling and greater safety. The principles of the system are based on control and stability augmentation strategies. Each subsystem has two observers which control the force of the actuators according to the vehicle dynamics. The system features a driver support system which allows the average driver to employ the full performance potential of the vehicle in exceptional situations, and an artificial response control system to ensure optimum response and comfort. Application of the system allows the driver to experience a new level of performance and a marked improvement in handling quality and ride comfort.

This paper describes a state adaptive control method for vehicle suspensions proposed by Hitachi, Ltd. The objective of the control is to improve riding comfort and driving stability in reaction to road iregularities, exterior wind forces, and changes in vehicle loads as well as in reaction to inertial changes during cornering, breaking, and accelerating. The objective is attained by making considerable use of the relative displacement data between the body and the suspension. The state adaptive control system includes four shock absorbers whose damping forces can be tuned in three stages, four height sensors which measure the relative displacement, a vehicle speed sensor, and a microcomputer which decides the optimal damper stage. The validity of the proposed control method is shown through computer simulations and actual driving experiments. Vertical acceleration is reduced by about 55 % by switching from the soft damper to the hard damper in a computer simulation.

Magnetic Phase Shifter is the controlling element to make integral action, excellent in anti-noise performance and makes high stable and reliable controlling device. (1)* We have developed a new compact thyristor chopper equipment controlled by Magnetic Phase Shifter. This equipment has simple controlling circuit and many functions such as wide range duty factor control, adjustable plugging brake, speed up by field weakening, anti-rollback control and so on.

A 24 GHz doppler speed sensor for skid controls has been developed. The microwave sensor is designed using both waveguide and thin-film technologies and assembled into a small integrated unit measuring 27 x 10 x 9 mm. The radar unit and the control circuitry are housed in a waterproof module of 94 x 140 x 78 mm. Part of the casing forms a horn antenna, which radiates a vertically polarized beam incident at 45° on the road surface, when mounted on the vehicle. The error in speed measuring is usually less than 10 percent.

This paper reviews some of the methods and experience with the DRAM Program, as it has been developed for interactive simulation of realistic mechanical machinery. The Program has been made interactive by increasing solution speed and providing for output of a moving drawing of the mechanism on time shared graphic display terminals. At the same time program generality has been expanded by including effects such as Coulomb friction and impact.

Conclusions based on the airborne experiments with laser radars are summarized in this paper. Details of the equipment and the flight procedures will be displayed during the oral presentation at the conference.