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In recent years, the number of reported traffic accidents due to sudden deterioration in driver’s physical condition has been increasing, it is expected to develop a system that prevents accidents even if physical condition suddenly changes while driving, or reduces damage through vehicle body control. For this purpose, it is necessary to detect sudden changes of the driver’s physical condition, and research is being conducted widely. Among them, it is reported that some of such changes may appear in the heartbeat interval. In other words, by acquiring the driver’s heartbeat interval in real time, it may be possible to detect the sudden changes, and reduce traffic accident. Even if a traffic accident occurs, the damage can be reduced by emergency evacuation immediately after detecting sudden changes.

With the improved safety performance of vehicles, the number of accidents has been decreasing. However, accidents due to driver distraction still occur, which means that there is a high need to determine whether a driver is properly looking at the surroundings. Meanwhile, with the trend toward partial automatic driving of vehicles in recent years, it is also urgently required that the state of the driver be grasped. Even if automatic driving is not installed, it is desired that the state of the driver be grasped and an application for control be performed depending on the state of the driver. Under these circumstances, we have built an algorithm that determines of the direction a driver is looking, to make a basic determination of whether or not the driver is in a state suitable for safe driving of the vehicle.

There are such outside door handles called smart handles which have a transmitting antenna, a lock/unlock sensor, and a sensor detection circuit, with which operation of door lock is possible just by "touching" the electrostatic-capacitance type sensor of the handles.As the design of the outside handles, body color painting and Cr plating are adopted. However, if plating is applied over the entire surface of a smart handle, electromagnetic waves transmitted from the antenna will be blocked since plating material is electrically conductive. In addition to this, touching a part other than the sensor may change the electrostatic-capacitance of the sensor, which results in unwanted functioning of the lock/unlock sensor. Because of this, only part of the handle, which does not hinder the transmission of electromagnetic waves and does not cause unwanted functioning, is covered by plating, that is called, "Partially plated specifications" (Figure 1).

This paper reports the results of a study into a preview control that uses the displacement of the road surface in front of the vehicle to improve for front and rear actuator responsiveness delays, as well as delays due to calculation, communication, and the like. This study also examined the effect of a preview control using the eActive3 electric active suspension system, which is capable of controlling the roll, pitch, and warp modes of vehicle motion.

Clutch judder phenomenon is known as a vehicle vibration caused by the drive torque fluctuation from the clutch unit at takeoff. In this paper, a novel strategy for improving clutch judder phenomenon caused by the movement/tolerance between mechanical parts comprising the clutch system is introduced. In order to simulate the movements of the clutch system and of the vehicle drivelines precisely, we used numerical analysis software and have achieved high-grade prediction of the clutch torque fluctuation and the vehicle vibration. Using this method, we have developed a high-quality clutch system that enables smoother clutch engagement, and at the same time, development efficiency has been improved.

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.

Introduction of occupant classification system which has load sensor with a strain gauge built into the seat structure, and identifies occupant's physique by measuring weight on seat, and meets the United States FMVSS requirements (new FMVSS208 Requirement).

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.

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.

Sport Utility Vehicles (SUV) and light duty trucks have gained in popularity for the last several years and the demand for more car-like behavior has increased, accordingly. Two areas for potential improvement are vehicle stability and maneuverability while parking. 4WS (4 wheel steering system) is known as an effective solution to stability and low speed maneuverability. In this paper, we identify a new systematic design method of two degree of freedom vehicle state feedback control algorithm that can improve vehicle stability, and show its control effects for a SUV with trailer towing. Low speed maneuvering is improved when the rear tires are steered in negative phase relative to the front tires. However with a large rear steer angle at low speed, the vehicle's rear overhang tracks a wider swing-out path than a 2WS vehicle. For this concern, we propose a new swing-out reduction control algorithm.

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.

Switched Reluctance Motor (SRM) mainly has two advantageous characteristics such as no magnet and simple construction. These characteristics contribute lower cost and higher reliability compared with other motor systems such as brushless permanent magnet motors or induction motors. However, acoustic noise and output torque ripple should be improved when the SRM is applied to a traction system for passenger electric vehicle since these characteristics directly affect vehicle quietness and drivability. In this paper, we describe a system configuration of the SRM traction system for passenger electric vehicle. The SRM traction system includes an electric motor, transmission gears and power inverter module. Then, an approach to improve acoustic noise and output torque ripple is introduced. Generation mechanisms of acoustic noise and output torque ripple are analyzed.

This paper describes the investigation into the contact pressure and incidental deformation on the contact surface of the piston skirt which comes in contact with the cylinder bore in operation. Focused on the single piston static tests in the first place, relationship between the contact pressure on said skirt and the strains developed inside the skirt, and the relationship between the deformation of skirt face and the strains inside the skirt were studied. Then, the dynamic contact pressure onto the skirt in operation and the amount of deformation were calculated based on the relationships mentioned above using the factor of dynamic strains measured on an engine in operation. The deformation of skirt calculated using said dynamic strains was verified by the direct measurement of the skirt deformation. It was demonstrated that the thrust side of a piston skirt was largely deformed due to enlarged contact pressure caused by the piston slap subsequent to firing top dead center.

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.

As a process that enables the high-speed and continuous forming of lengthy materials with a constant cross-sectional configuration, roll forming offers much higher productivity than the stamping process. However, in case a change must be made to the shape of the cross section, the material must normally be stamped or joined with a part containing a separate shape. This affects productivity, increases the number of pieces, and degrades the material's appearance. This report describes the roll-forming technology that we developed, in which the cross section of the material can be changed gradually. This method adopts a system which uses a movable and rotatable roll-stand that enables high-speed, continuous roll-forming processes.

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.

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.

Responsiveness is one of the main characteristics of a brake booster. The design of a tandem booster, with its two boosting chambers, has a negative influence on high responsiveness. This report, using the CFD method for the air flow analysis, shows the way we found the most suitable air passage within the space of the given design of the current production tandem booster.

In this paper, we discuss vehicle directional stability and introduce advanced stability control (ASTC) to stabilize the vehicle during severe cornering. Vehicle behavior in a transient steering condition during severe cornering was analyzed by computer simulation. It was found that applying an external yaw moment makes the vehicle more stable. The effect of controlling the brake force response is also evaluated by simulation to determine the brake actuator response criteria. The actual vehicle test was performed with a pylon slalom using a hydraulic brake actuator. It is verified that the ASTC stabilizes the vehicle for transient steering maneuvers.