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Development of a system which utilizes technology for the recognition of a vehicle's surroundings. Research is currently taking place in many countries, the goals of which are to improve a vehicle's safety and convenience by reducing driver strain through the automation of the recognition, judgment, and operation capabilities that are needed when driving an automobile. To recognize the vehicle's surroundings, we have adopted an image sensor system which offers superior three-dimensional recognition capabilities. In this paper, we will introduce a inter vehicle distance control system which controls the vehicle's throttle and braking functions by detecting the position of the driving lane and the distance to the vehicle in front based on the images obtained by a CCD camera.

Airflow effect is one of the important functions demanded of a rear spoiler. It helps prevent mud or dust from swirling up behind the running vehicle, or in the case of driving in the rain or snow, helps prevent rain or snow from adhering to the rear window. During the design process, we often decide on the shape of a spoiler in a relatively short time, focusing primarily on its appearance. Therefore, we established a design method using the recently developed computational fluid dynamics (CFD) to determine the central cross sectional shape of a spoiler that produces a desired airflow effect. We verified its effectiveness through testing.

We have developed a Hall effect device based height sensor of a smaller size, and with higher temperature operation durability, as compared to conventional devices. Downsizing of the sensor is realized by decreasing a number of parts, and by employing a short bearing. Improvement in heat resistance is achieved by adopting an IC with sufficient heat resistance and a SmCo magnet with high coercive force. In addition, a sensor of a high degree of accuracy is accomplished by improvements in linearity and robustness of magnetic characteristics. Development of a small, heat-resistant and accurate height sensor will promote the spread of systems using a height sensor, such as a High Intensity Discharge (HID) headlamp.

We have developed a power sliding door (PSD) system driven by a push-pull cable. The door closure and slide are operated by different actuators to limit the force required for a compact, light-weight drive unit. This paper introduces the concept of the PSD system using a push-pull cable drive. Two new technologies to achieve the PSD system are also described. One is the door position control for increasing the push-pull cable reliability. The other is a compact position sensor to accurately detect the sliding door's position.

Rear steering system can improve vehicle stability using active control of the rear wheel angles. For designing the rear steering system, environmental conditions, performance deterioration due to aging and component variation as a result of manufacturing tolerance under mass production must be taken into consideration. We have applied two-degree-of-freedom (2DOF) feedback control with feedforward control for the motor servo control so that the rear steering actuator can track the target rear steering angle accurately and stably. The control system is designed based upon a nominal mathematical model and its variation range. As a result, the rear steering actuator can be controlled with excellent performance and high reliability. This paper describes the mathematical model construction in the frequency domain and a robust motor servo controller design based on 2DOF feedback control with feedforward control.

Exhaust emission regulation has become stricter year by year because of the global movements of environment protection. In consequence, turbocharger application to diesel engines became indispensable. Especially a variable geometry turbocharger (VGT) is perceived as the essential item. Of late years, the diesel engine has a trend of higher exhaust temperature to increase specific output. At the same time, needs of the turbocharger application to the gasoline engine has been rising again in order to reduce the size. In spite of this trend of the emission temperature increment, VGT of the variable nozzle vane type which is commonly available in the current market has problems of high temperature resistance due to its complex structure. AISIN SEIKI has developed a variable flow turbocharger (VFT), which is able to resolve those problems.

It is well known that the self-aligning torque decreases before lateral force is saturated. Focusing on this self-aligning torque change, an estimation method has been developed to detect the friction condition between steered wheels and road surface before the lateral force reaches the friction limit. The lateral grip margin (LGM) is defined based on the self-aligning torque change, which is obtained using the EPS torque and motor current information. The LGM is theoretically analyzed based on the tire model and experimentally verified through the full-scale vehicle test. Moreover, the estimated LGM is applied for the chassis control systems to improve the vehicle dynamics performance.

In order to cope with the increases of the consciousness of safety driving and the aged drivers, AISIN SEIKI CO., LTD. and TOYOTA MOTOR CORPORATION have aimed at improvements in rear view visibility of outside mirrors running under the raining conditions (water cleaning), and have developed mirror with water cleaning device utilizing ultra sonic vibrations. The mirror was named as ULTRA SONIC VIBRATING MIRROR and have been installed with a TOYOTA flagship car “CELSIOR” corresponding to “LEXUS” sold in the U.S.

A newly developed parking assist system, which is based on rear view camera, is disclosed. System features include ‘parallel parking aid’ with voice guidance message along with several guidelines superimposed onto the rear view camera image. Voice guide message helps driver understand appropriate timing for each procedure of parallel parking. The system was designed to let driver follow the system by voice message rather than visual guide information through the screen for safety reason. The guide algorism is designed under ‘two turns’ parking maneuvers so that required longitudinal parking space becomes minimal. A key development of this system, which is to design the guide algorism to avoid collision to adjacent vehicle during parallel parking operation, is also discussed in this paper. User can select either ‘parallel guide’ or ‘normal (such as garage parking)’ mode through touch screen switch on display surface.

The metal top is used for convertible cars since the exterior design when the rooftop is closed is also important. A retractable metal top system which can automatically retract and extract the metal top has been popular to increase commercial values for the luxury convertible cars. We have developed the metal top open-close system comprising metal top,package tray and luggage panel operation link-mechanism units driven by electric motors. The metal top can be retracted or extracted in approximately 25 seconds by controlling the metal top system and the side and quarter window motors. The roof panel is pre-load so that the cabin air-tightness for high speed driving is maintained. The metal top is compactly retracted since the slide and side package trays are synchronized. Enough luggage space is secured using the multi-link mechanism to open and close the luggage panel. This retractable metal top system is equipped with the LEXUS SC430. (Fig.1) [1]

We have developed Sensor-less Memory Seat system that requires no position sensors such as Hall ICs etc.. It detects the rotation of DC motor by current ripple signals in motor operating current. The developed Sensor-less position control system can attenuate a wide frequency variation of Motor current noise which varies depending on motor condition and convert small current ripples to Pulse signals in proportion to the rotation of DC motor. We realized low cost position control method for use in Memory Seat system.

As automotive electronic systems advance, the wire harness is the mainstream for necessary wiring in resin-made motor-driven actuators with wire connection labor and purchased-parts accounting for the majority of costs. As a means to eliminating the harness, there is a method of forming the conductive material on the inside, but this method leads to cost increases when there is a comparatively large number of wires because the required die insertion time becomes longer and automatic insertion equipment becomes necessary. The following paper reports on an integrated high-speed process that combines stamping and injection molding into a single process.

An active suspension system controls a spring constant and an attenuater in real time using a power supply. Generally, the hydraulic pressures are used for transmitting the power. Therefore, a highly reliable and inexpensive control system has been required for a commercial use. This has been achieved by developing a mechanical fluid servo valve which comprises a simple combination of a solenoid valve and a spool valve. The technical problem of the valve vibrations has been solved through the numerical analyses, the fluid flow visualization tests and the vehicle tests.

This active-drive wheel speed sensor, developed by the high-frequency magnetic system, enables detection of very slow wheel speeds - hitherto difficult to accomplish with any conventional type of Magnetic Pick up - by applying the eddy current effect through the high-frequency magnetic field. The following report presents an analysis of the magnetic circuit which integrates the magnetic-field generating coil with the detection rotor, and the unique circuit system which ensures strength against eccentricity of the wheel rotor and air gap variations, etc.