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This paper provides an overview of automotive electronic systems put into products over the past decade, and describes automotive electronics which have been demonstrated in experimental cars. In addition, future electronic systems found to be promising for the practical use in coming years and the direction of development of electronics are also discussed, as an extention of the overview mentioned above.

This paper describes the Electro-Multivision map navigation software mounted in the Toyota Soarer (1991). The following functions are required of on-board map navigation software: 1. Indication of the exact position of the vehicle to the driver 2. Determination of the optimum path to the destination and presentation of this route to the driver in the simplest way 3. Accommodation of a wide variety of destinations and settings for different users The following gives some examples of how these functions are achieved and outlines the associated technologies. 1. Path finding and associated display technology Path finding algorithm and technology for displaying the calculated on the map; construction of a data base on CD-ROM 2. Technology for determination of the current position utilizing map matching and the global positioning system(GPS) A method with improved reliability based on two current position outputs obtained using map matching and the GPS and the mutual compensation method 3.

The hybrid system has the typical advantage that it can realize various types of system control, because the system has two power units, engine and motor. On the other hand, however, constraints are increasing due to the complexity of the vehicle system. Compared to the conventional HILS construction and application, there are mainly two typical characteristics or themes for HV-HILS (i.e. HILS for hybrid vehicle control development). Firstly, HV-HILS requires full vehicle simulation environment, because the plural ECU control logic is intricately intertwined. Secondly, recent HILS system needs to run with more accurate or complicated plant models which are necessary to develop more accurate vehicle control logic.

Electronic Control Units (ECUs) for automobiles are usually composed of a main single-chip microcomputer and peripheral circuits with some standard and/or custom ICs. The peripheral circuits vary with the kinds of control or models of automobiles. When the peripheral circuits are replaced with a single-chip microcomputer, the ECU becomes compact and low in cost. This is because the ECU is constructed with only two LSIs and can be used for various kinds of control and various models of automobiles only by changing the program of the microcomputer. The microcomputer, however, requires many I/O functions and high reliability. We have developed a new 4-bit microcomputer suitable for these requirements. The new microcomputer has two remarkable features. One is powerful I/O functions such as high speed I/O, serial I/O, parallel I/O, analog I/O, and default output that is generated in place of the calculated output by the main CPU when it fails.

A new ABS and Traction control system (TRAC system) has been developed and put into mass production in a new model LEXUS LS400. The TRAC system controls Sub-Throttle Valve and brake hydraulic pressure independently for left and right wheels. To realize the ABS and TRAC system,it is necessary for the Electronic Control Unit (ECU) to process complex algorithm and high speed calculation. The ABS and TRAC ECU for LEXUS LS400 is constructed by 3 TOYOTA custom 8-bit single chip microcomputers. Each CPU performs wheel speed calculation,ABS control and TRAC control,sharing the common data through high speed serial communication. This paper describes the function of each CPU,the method of CPU communication and fail safe function in the ECU.

The structure of HCCI (homogeneous charge compression ignition) combustion flames was quantitatively analyzed by measuring the two-dimensional gas temperature distribution using phosphor thermometry. It was found from the relation between a turbulent Reynolds number and Karlovitz number that, when compared with the flame propagation in an S.I. engine, HCCI combustion has a wider flame structure with respect to the turbulence scale. As a result of our experimentation for the influence of low temperature reaction (LTR) using two types of fuel, it was also confirmed that different types of fuel produce different histories of flame kernel structure.

We urgently need to develop the next generation of automotive technology to support energy conservation and the global environment. For this we need an advancement of the Laboratory Automation System (LAS). However, restructuring the hardware and software of the LAS requires enormous amounts of time and costs. To solve the problems of the LAS development, we formed a user-vendor working group, which then established the common rules of LAS and IMACS (Integrated Measurement And Control System). IMACS are software-centered rules, characterized by the stratification of LAS and the interface called software parts. So far, we have integrated IMACS into five engineering fields. A total of 11 testing machine vendors participated in the development. We manufactured about 350 software parts and made their specifications openly available. As the next step, we are collecting software parts by deleting redundant functions.

Toyota has developed a new continuously variable transmission (CVT) named “Super CVT”. The Super CVT has a wide ratio coverage and adopts a newly developed integrated control system with a direct injection gasoline engine (D-4) equipped with electronically controlled throttle. The combined package has achieved good fuel economy and a high overall level of performance. This paper shows the major features and performance of the Super CVT.

In the field of automotive gasoline engines, new products aiming at greater fuel economy and cleaner exhaust gases are under development with the aim of preventing environmental destruction. Severe ignition environments such as lean combustion, stronger charge motion, and large quantities of EGR require ever greater combustion stability. In an effort to meet these requirements, an iridium plug has been developed that achieves high ignitability and long service life through reduction of its diameter, using a highly wear-resistant iridium alloy as the center electrode.(1)(2) Recently, direct injection engines have attracted attention. In stratified combustion, a feature of the direct injection engine, the introduction of rich air-fuel mixtures in the vicinity of the plug ignition region tends to cause carbon fouling. This necessitates plug carbon fouling resistance.

On board multiplexing communication system is regarded as a necessary technology for the future of electronic system in automobiles. Many companies are developing multiplexing systems and the ISO and SAE are active in establishing standards for communication protocols. The proposed communication protocol specifications have different specifications. Consequently, no compatible evaluation standards existed, and it was difficult to compare one protocol to another. Therefore, to assist the standardization activities of the IS0 and SAE, we have developed an evaluation method for distributed multiplexed communication systems and evaluated each of the proposed protocols using this method. These evaluations were performed from the point of view of the future users of these systems. In this paper we present the results of the experiments on distributed multiplexed communication systems each of which consists of communication IC and the proposed physical layer.

A smart analog integrated circuit (IC) is developed for use in an electronic control unit for an automotive variable power-steering system. This IC accepts a vehicle speed signal as its input, performs signal processings such as frequency to voltage conversion and function generation, and then as its output generates a pulse width modulated (PWM) signal whose duty corresponds precisely to a given piecewise linear function of the vehicle speed. The PWM output is used as a driving signal to a power MOSFET for the actuation and control of a linearly variable solenoid valve to vary the force needed for steering effort in a prescribed relation to the vehicle speed. The IC is fabricated by monolithic bipolar integrated circuit technology and has about 750 device elements in a chip size of 5.7 by 3.1 mm2. It is enveloped in a shrinked dual in-line package with 24 pins.

A new method to measure in-cylinder flame propagation and mixture distribution has been developed. The distribution is derived from analyzing the temporal history of flame spectra of CH* and C2*, which are detected by a spark plug type sensor with multi-optical fibers. The validity of this method was confirmed by verifying that the measurement results corresponded with the results of high speed flame visualization and laser induced fluorescence (LIF) measurement. This method was also applied to analysis of cyclic combustion fluctuation on start-up in a direct injection spark ignition (DISI) engine, and its applicability was confirmed.

Toyota Motor Corporation has developed a new 6-speed automatic transmission (U660E) for the front-wheel drive vehicles and large displacement engines. The U660 E was adapted to achieve improved environmental protection, and meet safety standards, which are large concerns for the society and customer satisfaction, by being small, light, highly efficient, quick response, and high shift quality. Toyota fundamentally improved both the hardware and software of the control system to meet these important goals.

This paper describes the development of the electrical systems for the integrated control system which unified automobile electronic control systems and led to a dramatic improvement in vehicle dynamics. An outline of the system is presented first, followed by actual automobile application examples of electrical systems employing medium-speed multiplexing.

With the increasing use of electronic control systems to improve vehicle dynamics, there is an ever growing need to transfer control information among electronic control units(ECUs). To meet this need, a protocol was proposed for high-speed multiplex in the previous SAE paper 910463. Based on the paper, a prototype IC for high-speed multiplexing control was developed. First, a further analysis was made of the information which is transferred among ECUs. As a result, it was found that the information has certain distinctive characteristics. These characteristics are so distinctive that it may be relevant to devise a new protocol for communication. Based on the analysis, a new form of token passing method was implemented. By using this method, it is easy to calculate transmission latency time. So this method is suitable for a real time control application like vehicle dynamics control.

Several methods have been studied by using adaptive control in order to tune parameters of the cruise control automatically. But theoretical analysis has not been done by the reason of severe non-linearity. In this paper, a vehicle dynamics model is made with theoretical analysis, and two adaptive control methods to assist the conventional PID controller are proposed.

We have developed a vehicle navigation system with route guidance enhanced by voice messages. This paper describes the human factors engineering study carried out to develop the software specifications for the voice route guidance. Results of experiments for verification of the effectiveness of the system, including objective measurements of drivers' glance behavior and mental workload, will also be reported.

With an ever growing demand for the enhanced control of a vehicle and for the reduction of power and signal distributing wires in a vehicle, there is a pressing need for the development of Local Area Network (LAN) in a vehicle. LAN enables the exchange of various data among several electronic control units (ECUs), and results in the higher controlled performances of a vehicle and the reduction of the wires. In response to this need, two integrated circuits for vehicle multiplexing communication are developed. One is a communication control IC and the other is a bus driver/receiver IC, both based upon the standard of a PWM type of the J1850 for a communication protocol. The communication control IC is designed to have distinctive features such as a highly fail-safe operation and the reduction of the overhead for communication imposed on a central processing unit (CPU) of the ECU.

A practical shape optimization technique is presented. We employed the basis vector method to parameterize the shape of the structural domain that is usually discretized by the finite element method. VMA/GENESIS software, the optimization system with finite element analysis, sensitivity analysis, and numerical optimization capabilities, was used for this study. Various design problems such as body, chassis, and engine parts design are solved to demonstrate the effectiveness and the robustness of the present approach for automotive applications.

This paper describes the multiplex communication protocol, BEAN (Body Electronics Area Network), developed for body control system on passenger cars which in recent years has increased the scope of multiplex communication. BEAN is based on a protocol developed in 1992 (SAE920231) but expands upon the performance in areas, such as the suitability of the ID system for increase of ECUs, the variable data length enabling the transmission of diagnostic data, and the transmission rate, while keeping the cost and radiation noise level low. The software size of BEAN is compact enough to be implemented by general purpose 8bit MCUs which have recently seen improvements in performance. The BEAN communication devices are available corresponding to the scale of the application and configuration of the ECU taking into account the software capability. This protocol was evaluated using simulation with the body control system on luxury passenger cars.