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This paper proposes a new voice and data wireless communication method for telematics services. Data-voice (DV) modems have conventionally been used for simultaneous transmission of voice and data. With this method, however, one line is split between the data part and voice part. Lost data are retransmitted, but the voice signal is not resent because voice communication requires a real-time characteristic. The new voice and data wireless communication method proposed here switches voice to a voice line and data to a data line.

People often feel discomfort when entering or exiting a vehicle because of a static electric shock. In the electronics industry, ionizers have been developed to prevent electrostatic discharges and contamination sticking around or on circuit components. Ionizers incorporate corona discharge principles to neutralize the static electric field. Using this idea, we developed an in-vehicle system to neutralize the human body charge. To accomplish this, the mechanism by which the human body attains a charge when exiting a vehicle was first defined. That definition was then used to determine the design characteristics of the system.

Curbing emissions of carbon dioxide (CO₂), which is believed by many scientists to be a major contributor to global warming, is one of the top priority issues that must be addressed by automobile manufacturers. Automakers have set their own strategies to improve fuel economy and to reduce CO₂ emissions. Some of them include integrated approaches, focusing on not only improvement of vehicle technology, but also human factors (eco-driving support for drivers) and social and transportation factors (traffic management by intelligent transportation systems [ITS]). Among them, electric vehicles (EVs) will be a key contributor to attaining the challenging goal of CO₂ reduction. Mass deployment of EVs is required to achieve a zero-emission society. To accomplish that, new advanced technologies, new business schemes, and new partnerships are required.

An electric vehicle (EV) is promising as clean energy powered vehicle, due to increased interest in fuel economy and environment in recent years. However, it requires to meet unique safety performance such as electric safety. Nissan has developed a new electric vehicle which achieves electric safety in addition to maintaining enough cruising distance and cabin space. This was achieved by I he development of an all-new platform for electric vehicles. The electric safety was enhanced by the protection of high-voltage components based on consideration of component layout and body structure, high-voltage shutdown by impact sensing system and prevention of short circuit by fuse in the battery. As an example of the protection of high-voltage components, the battery which locates under the floor was protected by elaborative packaging and multi-layer protection structure.

At Nissan we have developed a new parallel hybrid system for rear-wheel-drive hybrid vehicles. As the main components of the hybrid system, both the motor and the inverter have been developed and are manufactured in house to attain high power density for providing responsive acceleration, a quiet EV drive mode and improved fuel economy. Because the motor is located between the engine and the transmission, it had to be shortened to be within the length allowed for the powertrain. Therefore, new technologies have been developed such as high-density, square-shaped windings and an optimized magnetic circuit specially designed for concentrated winding motors. The inverter is sized to a 12V battery, which it replaces in the engine compartment. Despite its compact size, the inverter must have rather large current capacity to drive a high-power motor. Heat management is critical to the design of a small but high-power inverter.

Traction control systems (TCSs) serve to control brake pressure and engine torque, thereby reducing driving wheel spin for improved stability and handling. Systems are divided into two basic types by the brake control configuration. One type is a one-channel left-right common control system and the other is a two-channel individual control system. This paper presents an analysis of these two types of TCS configurations in terms of handling, acceleration, stability, yaw convergence and other performance parameters. The systems are compared with and without a limited-slip differential (LSD) under various road conditions, based on experimental data and computer simulations. As a result of this work, certain Nissan models are now equipped with a new Nissan Traction Control System with a rear viscous LSD (Nissan V-TCS), which provides both the advantages of a rear viscous LSD in a small slip region and a two-channel TCS in a large slip region.

Basic vehicle performance, such as Safety, Comfort and Economy, are by dependent on tire performance, and it is the air pressure in the tire which assures this performance. However, tire air has a tendency to leak naturally, making it necessary to check them periodically. Since a deterioration in vehicle performance resulting from a drop on tire air pressure can not be directly felt by the driver, the number of people maintaining their tires sufficiently is relatively few. There have been many tire pressure warning devices developed which advise the driver when the pressure drops below a prescribed level. Differing from conventional devices, the TWD-III features a 7-step digital display (at a pitch of 0.1 kgf/cm2) which shows the pressure of each tire within an optional range, and it also has a flat tire warning function. The employment of echo effect from clystal vibrator resonance precludes the need to attach a power source on the tire.

Electric Vehicles are very quiet at low speeds therefore people (especially the visually impaired) have difficulty recognizing that these vehicles are approaching. To address this concern, Approaching Vehicle Sound for Pedestrians system development has been discussed worldwide. In Japan, USA, Europe and China, government regulation is currently under study. As a solution to meet this concern, Nissan has developed the VSP (Approaching Vehicle Sound for Pedestrians) system for implementation on Nissan's first mass production Electric Vehicle. Nissan VSP emits a futuristic sound to satisfy 3 key stakeholders' concerns; for pedestrians to provide detectability, for drivers and neighborhoods to maintain a quiet environment. The sound emitted during forward motion has a “twin peaks and one dip” frequency signature, with modulation (or rhythmic structure) to accommodate human-beings ear frequency sensitivity, hearing loss due to aging and ambient noise conditions.

The expanded application of automotive electronics in recent years has increased the number of control switches, thus necessitating the optimization of their layout around the driver and improvement in operability. As an effective means in improving operability, switches mounted on the steering wheel have been developed, placing controls closer to drivers for easier access while driving. However, since the switches rotate along with the steering wheel, recognition and operation of those switches left a few things to be desired. Recently we developed a "steering wheel with a non-rotating center switch pad" where the pad section with the switches are kept stationary. In this paper we describe the general outline of this development.

This paper describes a new approach to solving various problems inherent in conventional multiplexed wiring systems. These problems include the fact that the quantity of cut leads, which determines the cost, is not reduced even though the bulk of the wire harness is decreased. Another problem is that the communications system has a very complex configuration. With the approach proposed here it has been found that the number of cut leads can be reduced by housing the communications circuits individually in each piece of electrical equipment. This can be accomplished by grouping together the wiring in which the signals activating electrical load units all flow in the same direction. Custom LSI circuits have been developed to simplify the communications circuits. All of these developments have been combined into practical multiplexed wiring systems for controlling the power Windows, automatic door locks and power seats.

This paper presents a lightweight, high-performance Lithium-ion Battery System developed jointly by Nissan Motor Co. and Sony Corp. for electric vehicle (EV) use. Electric vehicles are generally powered by a battery pack consisting of numerous cells connected in a series. Management techniques to elicit the maximum performance of the battery pack are needed, including a function for monitoring individual cells to prevent them from over-discharging. Because of high cell voltage, lithium-ion batteries enable the number of cells in a battery pack to be greatly reduced compared with other types of battery systems. They also allow accurate detection of the battery State of Charge (SOC) based on the battery voltage. These characteristics are conducive to the application of battery pack management technology. These concepts provided the basis for the development of a Lithium-ion Battery System for EV application.

This paper describes a high-power lithium-ion battery system that has been newly developed for application to hybrid electric vehicles (HEVs). The battery system was designed on the premise of an underfloor location so as to avoid sacrificing interior spaciousness while providing the power output and recharge performance required by the hybrid propulsion system. To meet these requirements, efforts were made to increase the specific power and to reduce the heat generation of the battery to previously unattained levels. As a result, exceptionally high specific power of 1,200 W/kg per cell, battery pack power of 25kW at 20% state of charge (SOC), and high charge/discharge efficiency of more than 95% in the urban driving schedule has been achieved. The battery pack is composed of two box-shaped modules designed with a low height in consideration of underfloor mountability.

A human body model has been developed for conducting personal computer simulations to evaluate physical work loads, especially muscle loads, associated with the driving position and arm and leg motions. The validity of the model was confirmed by comparing estimated work loads with electromyographic measurements. Correlation analyses were conducted to examine the relationship between the estimated loads and subjective evaluations. The results indicated the regions of the body where loads had the largest impact on the perceived sensation of physical effort and were used to derive an index for evaluating the overall work load of the entire body. The simulation method was used to evaluate control switch positions, driving position and vehicle entry/exit motions.

This paper describes a newly developed HC-adsorption three-way catalyst and adsorption system that reduce cold-start HC emissions with high efficiency. This system is the first of its kind anywhere in the world to be implemented on production vehicles. An overview is given of the various improvements made to achieve higher cold-start HC conversion efficiency. Improvement of conversion performance was accomplished by (1) increasing the thermal stability of the HC adsorbent, (2) improving desorbed HC conversion efficiency and durability and (3) optimizing the geometric surface area (GSA) of the substrate. Concretely, the thermal stability of the adsorbent was improved by enhancing the high-temperature durability of zeolite. Improvement of desorbed HC conversion efficiency was accomplished by improving the OSC material so as to match the temperature rise characteristic and usage temperature of the catalyst.

In December 2006, Nissan announced its Nissan Green Program 2010 (NGP 2010), a mid-term environmental action plan that includes initiatives to reduce vehicle emissions. In line with this plan, the company intends to introduce a new and original hybrid system in fiscal year 2010. Specifically, this system-called the “Infiniti Direct Response Hybrid”-is a one-motor, two-clutch parallel hybrid system that eliminates the need for a torque converter. It will be featured in the 2012 Infiniti M35 Hybrid and provides the following advantages. 1 Significant improvement in fuel economy even in Highway driving 2 Better response and a more direct feeling 3 Lightweight and low cost This one-motor, two-clutch system without torque converter possesses a simple but highly capable architecture that is new to the passenger vehicle segment.

The performance capabilities which hold the key to the acceptance of electric vehicles (EVs) includes range and acceleration. Range can be effectively extended by increasing the size of the batteries used, but it requires a trade-off with acceleration performance which deteriorates due to the increased weight. The FEV-II and Prairie Joy EV exhibited at the 1995 Tokyo Motor Show were equipped with high-performance lithium-ion batteries that achieve both high energy and power densities, to provide an excellent balance of range and acceleration. Futher more, the batteries exceptionally high charging efficiency enables them to accept regenerative energy effectively. This feature improves range, and also allows the battery state of charge (SOC) to be determined accurately. This characteristic was used to develop a highly accurate battery model which was incorporated in a simulation program for predicting EV performance.

Recent environmental concerns such as atmospheric pollution and energy conservation have intensified the need to develop pollution-free, energy-efficient vehicles. One such solution is the electric automobile which draws its power from rechargeable batteries. There are few vehicles on the road today because present batteries can store very little energy compared with that of a tank of gasoline. To obtain adequate range, this concept vehicle adopts a new battery which can be recharged to 40% of capacity in six minutes. This super quick charging system makes it possible to recharge the batteries at an electric recharging station just as gasoline-powered vehicles are refilled at service stations. The electric concept vehicle also has improved aerodynamics, reduced rolling resistance and a lighter curb weight, which help to assure adequate range.

This paper presents the electrically driven intelligent brake system that has been developed for electric vehicles, which are expected to penetrate markets rapidly amid the ongoing energy paradigm shift. This brake system achieves a cooperative energy regeneration function and high responsiveness while providing braking performance, system reliability and vehicle mounting ease equal to that of conventional brake systems with a vacuum booster. This paper outlines the newly developed brake system and describes how to decide the target brake force which is achieved a regenerative braking capability for recovering energy efficiently without sacrificing braking.

An electrically-driven, intelligent brake unit has been developed, to be combined with a regenerative braking system in electric vehicles (EVs) and hybrid electric vehicles (HEVs) which went into production in 2010 - 11. The brake pedal force is assisted by an electrically driven motor, without using vacuum pressure, unlike conventional braking systems. The actuator can be implemented to coordinate with a regenerative braking system, and to have adjustable pedal feel through use of a unique pressure-generating mechanism and a pedal-force compensator. In this paper, we describe features of the actuator mechanism and performance test results

This Paper describes a computer-controlled power steering system that has been developed and applied to production vehicles. The system provides full power assist at parking speeds, and gradually decreases assistance with increasing vehicle speed to give a normal unassisted “road feel” at highway speeds. The system enables a driver to choose one assistance characteristic among three choices at the flick of a switch, according to the driver's preference and road conditions. A solenoid-operated bypass valve is used to reduce the hydraulic fluid supply to the steering gear, which results in a heavier steering effort. The most suitable valve characteristic curve which corresponds to the increased pressure in the system due to the applied torque is discussed in this study. It is shown that detection of the velocity of steering wheel rotation and extension of the range of characteristics possible are effective ways to ensure good control over the power assistance.