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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).

Over the past decades, the automotive industry has made significant efforts to improve engine fuel economy by reducing mechanical friction. Reducing friction under cold conditions is becoming more important in hybrid vehicle (HV) and plug-in hybrid vehicle (PHV) systems due to the lower oil temperatures of these systems, which results in higher friction loss. To help resolve this issue, a new internal gear fully variable discharge oil pump (F-VDOP) was developed. This new oil pump can control the oil pressure freely over a temperature range from -10°C to hot conditions. At 20°C, this pump lowers the minimum main gallery pressure to 100 kPa, thereby achieving a friction reduction effect of 1.4 Nm. The developed oil pump achieves a pressure response time constant of 0.17 seconds when changing the oil pressure from 120 kPa to 200 kPa at a temperature of 20°C and an engine speed of 1,600 rpm.

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.

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.

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.

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.

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.

1 There are two design challenges of the flow path switching valve in a three-stage variable discharge oil pump. The first is to obtain the required discharge pressure characteristics and the other is to prevent hydraulic vibration. Therefore, we established technologies to determine the shape of the valve and the valve housing that resolve these two challenges. The technology to obtain the required discharge pressure characteristics solves equations that are statically true, such as the equations for the equilibrium of forces and hydraulic orifice. The hydraulic vibration control technology derives a differential equation that takes transient behavior, including oil elasticity and inertia, into account first. Then, the derived equations are converted to a transfer function that indicates the valve behavior according to the input of oil pressure changes. And then the stability criterion is applied to judge whether hydraulic vibration occurs or not.

Recently, for the protection of the environment, the regulation of automobile fuel consumption and exhaust gas emission has been strengthened. To improve fuel economy, it is demanded that each engine part contributes to reducing the workload of the engine, even the engine lubrication oil pump. In response to this, a new variable discharge oil pump was developed. It is the world's first internal gear type oil pump that has electronically controlled continuously variable discharge. The work performed by the pump chiefly takes two forms: sliding friction of the rotor and pumping work which moves the oil. First, in developing a variable discharge oil pump, a new tooth profile of the rotor was developed to reduce its sliding friction. As a result, the sliding friction of the rotor was reduced by 34% while maintaining the same theoretical oil discharge rate. Next, a variable discharge mechanism using an internal gear was developed.

We developed amorphous alloy thin films having TCR(temperature coefficient of resistivity) less than ±5 ppm/°C for strain gauge applications. Thin film strain gauges are directly formed on metal substrates insulated with SiO2. These gauges have excellent aging stability at high temperature. The resistivity shows a drift in ▵R/R less than ±0.03% at 120°C in 1000 hours. We developed a pressure sensor and an acceleration sensor with high accuracy and reliability, employing these gauges.

Aiming at improved reliability and cost reduction of position sensors for automobiles, we tackled with the challenge of developing long life contact type potentiometer which has a simple construction and cost advantage. We made clear the wear characteristics of the resistor materials and the mechanism how noise occurs, and developed a long life, low noise resistor material, and the double - layer resistor structure which has excellent characteristic in durability. We also clarified the ways of using brushes according to applications through the investigation of the relationship between the contact shape and the amount of wear of the resistor. Based on these investigation, we have developed a highly reliable throttle position sensor and a long life vehicle height sensor.

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.

The usage of GPS (Global Positioning System) in various fields is growing. The best solution known for GPS outage problems in vehicle navigation systems is DR (dead reckoning). An inertial system based on distance and heading sensors backs up the GPS equipment by relaying information during periods without satellite visibility. Because the DR inertial system delivers relative positions and GPS absolute positions, it seems logical to combine the two to minimize the cumulative drift errors,mainly due to distance and heading sensor resolution. For in-vehicle GPS receiver, there are problems in maintaining the operation performance even in unfavorable environments like an urban area and using antenna layout which does not hinder the vehicle design. In the text,the solutions to these problems and a new type GPS receiving system which is equipped with Toyota Electro-Multivision(1) are described.

By developing a mechanical-firing sensor using rotational inertia effect, we have completed miniaturization of the sensor and have developed a new-type mechanical-firing airbag system. This airbag system has been confirmed to have superior occupant protection performance after conducting a variety of vehicle crash tests and sled tests.

Recycling SMC molded parts has become one of the most important and urgent subjects. This paper discusses a system to recover SMC molded parts and recycle them to original automotive products. “Sandwich structure” in the core layer of which regrinded filler is concentrically involved, is very useful for increasing the volume of involved regrinded filler. This structure provides more weight reduction of recycled parts.

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.

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.

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.

Drive train components (transmission, differential gears, etc.) can be made smaller and lighter if the excessive torque exerted on them can be reduced during the quick start of a vehicle. An orifice put in the hydraulic clutch piping path is an effective method. However, increased oil viscosity at low temperatures (0°C or below) makes the “pedal feel” worse. In order to increase the orifice diameter for better “pedal feel”, a shape memory alloy spring, for operation at low temperatures, was developed by adding cobalt to the nickel-titanium alloy. Consequently, a Variable-Orifice valve, using the shape memory alloy spring, is practical.