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Customers tend to require more comfortable climate control in vehicles. This paper is concern with a new infrared sensor that detects surface temperature at six separate locations, and a climate control system that incorporates the sensor. In a conventional system using an air temperature sensor and solar radiation sensor, climate conditions are usually controlled according to the thermal load. It is believed that more comfortable climate control can be realized by using an infrared sensor to detect passengers' surface temperature. The sensor consists of a lens, an IC with six thermopiles, a circuit and a case, and has been improved to detect in-cabin surface temperature accurately even under severe environmental conditions. The HVAC system controls the outlet air temperature and mode individually for each seat according to detected temperatures.

Increased interest in global warming issues requires rapid improvements in reduction of CO2 emissions. The automotive industry is placing high importance on improving fuel economy performance across their entire product lines. Charging Management System is a necessary element towards fuel economy improvement. Many of today's charging management systems perform at least two important functions: improving efficiency based on vehicle motion, and detecting battery state of charge. These systems become more complicated as more components (i.e. generators, current sensors and ECU) and software are added. Therefore, it is difficult to develop charging management systems for an entire product line and difficult to retrofit the system for vehicles already in production. A stand-alone charging management system solves these issues. This system is independent of the other vehicle systems. The software for improving fuel economy is installed in the generator or current sensor.

There has recently been an increasing need in various automotive monitoring and control systems for a simply structured and highly reliable high-pressure sensor to detect the higher pressures of oils, hydraulic fluids, air and air conditioning refrigerants. A simple, newly devised approach to sealing oil filled high-pressure sensors is introduced in this paper. The new structure utilizes a resin instead of the metal and glass conventionally used for hermetic sealing oil filled high-pressure sensors. This is made possible by the combined use of oils with large effective molecular diameters and carefully optimized design of shape and size of the sealing faces between sensor parts. The use of a sealed metal diaphragm allows for extensive use of the sensor with many different kinds of pressure media and in various applications.

We propose a novel millimeter wave radar system and object detection algorithm for automobile use by using advanced null scanning method. Generally, null scanning method can achieve a higher resolution and a more compact sensor size compared to beam scanning method, but needs huge computing power. We introduced the theory of forgetting factor into it and developed a new null scan algorithm. It achieved a high lateral object separation ability of less than 3 degree, and a quick response under feasible computing power in simulation and test vehicle. These technologies enable compact and high performance radar for advanced safety system.

Increasing electric loads in a vehicle causes over-discharge of a battery and drag torque due to an alternator. This paper gives a system concept of vehicle electric power flow management to solve these issues. Its primary function includes preserving electricity in a battery, stabilizing electric bus voltage, interfacing with vehicle torque control system, and improving fuel economy. The key point to realize such a system is a unified structure. It offers ‘Plug and Play’ function for electric power management components. Newly developed Vehicle Electric Power Flow Management System (VEF ) totally controls electric power flow in a vehicle. VEF contains an Electric Power Manager and its functional sub-systems, and controls them with the key parameter ‘electric power’. The sub-system includes Generation, Storage, Conversion, and Distribution to the loads.

Up to now, while automobile electric packages have demanded the high density for small and light products, electric leaks, which have occurred due to condensation, have been a major problem. To prevent any electric leaks, a conformal coating on the electric parts (ex. ECU: Electronic Control Unit) has been needed, but in general the design rules of the conformal coating (ex. Application area) is vague. Therefore, DENSO demands to clear the design rules of conformal coating electric package for higher reliability. To meet the demand, DENSO has developed a condensation simulation method using CAE that can show the occurrence condition of condensation fast and accurately. In the result, DENSO has been able to get the design rules where to need the conformal coating in the electric package for automobiles.

Automotive manufacturers are working towards protecting the global environment by using filters to reduce particulate matter (PM) emissions from their vehicles. There is a growing demand for sensors that detect the small amounts of PM leaking through these filters, as they can aid in performing on-board diagnostics (OBD) and monitoring the function of these filters. Currently, vehicles predominantly use an electric resistance type PM sensor, which applies a voltage between electrodes, collects PM, and senses the generation of PM path. However, in response to tightening regulations on PM-OBD, the response time of the sensor needs to be optimized. Furthermore, the fast response time must not degrade the poisoning resistance in order to ensure durability. To shorten sensor response time, we have developed a 20 μm-gap electrode structure using a cross-section of laminated alumina sheets with printed electrodes, which can form PM paths at small PM amounts.

Toyota Motor Corporation has developed a new battery electric vehicle (BEV) on the dedicated e-TNGA platform for BEVs, which was designed to lower the center of gravity of the vehicle and increase body stiffness. In addition to a full-time 4WD system, another feature of this new BEV is its pleasurable driving experience. A new inverter drive unit was developed for this system. Unlike the previous inverter, the advantage of the new inverter is that it is small enough to be mounted inside the transaxle housing, thereby contributing to the availability of interior and luggage space. The temperature rise of the power semiconductors in the inverter was reduced considerably by the development of a new power semiconductor for BEVs. This enables a parallel layout of two power semiconductors instead of three. The components of the inverter were also downsized. A coreless current sensor was adopted, and capacitors were developed with significantly lower capacitance.

The lateral DMOS (LDMOS) had been developed for intelligent power IC[1][2] for ECU (Electric Control Unit). The process and device simulation methodology are used while developing a devices. The physical model and parameter in analytical model are calibrated to enhance the accuracy of the simulation and to reduce lead time and costs.

Reducing vehicle CO2 emissions is an important measure to help address global warming. To reduce CO2 emissions on a global basis, Toyota Motor Corporation is taking a multi-pathway approach that involves the introduction of the optimal powertrains according to the circumstances of each region, including hybrid electric (HEVs) and plug-in hybrid electric vehicles (PHEVs), as well as battery electric vehicles (BEVs). This report describes the development of a new PHEV system for the Toyota Prius. This system features a traction battery pack structure, transaxle, and power control unit (PCU) with boost converter, which were newly developed based on the 2.0-liter HEV system. As a result, the battery capacity was increased by 1.5 times compared to the previous model with almost the same battery pack size. Transmission efficiency was also improved, extending the distance that the Prius can be driven as an EV by 70%.

This paper proposes an oil degradation sensor that informs the best time for oil replacement to achieve the right balance with oil conservation and engine protection. We found that free radicals in the engine oil generate by chain decomposition reactions of hydrocarbons by heat and the amount of them increases with an increase in running distance. Based on theoretical analysis and experiment results, the free radical concentrations have high correlations with pH and base number. The sensor using the principle of electron spin resonance (ESR) can measure the amount of free radical molecules in a non-contact method. The sensor successfully detected free radicals produced by the degradation of actual engine oil.

In applying a LAN to automotive electronics systems, an optimal protocol has been adopted for each system so far, such as body electronics system, entertainment system, service system and power train system. As low cost communication protocol “BEAN” (Body Electronics Area Network; SAE paper 970297) adopted to wider range of functions on vehicle, ECU's numbers are increased which have BEAN communication and that is branched to plural communication networks. We have succeeded in rationalization of those network systems with the gateway function on a delegated ECU for each LAN system on vehicle. And this system also realized the connection to after market products by data exchange through the gateway function, while securing vehicle fail-safe.

In 1997, we have applied laser technology to the world's first practical adaptive cruise control (ACC) system. The ACC system is based on 2-dimensional scanning laser-radar-sensor technology that is supported by highly reliable high power diode laser. Now, we have developed 34W output power multiple-quantum-well (MQW) diode laser. The power of 870nm near IR diode laser is twice as high as conventional one, thus it meets the strong needs for robust detection of the reflective laser beams from the moving vehicle ahead. Furthermore, Au-Sn-Ni a new alloy solder has been employed to sustain high degree of vibration and thermal shock to raise reliability. The acceleration life-tests at high temperature pulsed operation demonstrate the high reliability of developed 34W high power diode laser.

Recently, automotive semiconductor devices need miniaturization. One of the most important technologies is the package which encapsulates devices. In addition, the outer shape of the package is needed to change according to the mounted space. Conventional devices are mounted in the case, and encapsulated with potting resin. However this package structure is difficult to miniaturize because the case size limit. This report describes the development of the packaging technology for miniature and particular outer shape. The devices are set in the cavity and molded to one package. The three-dimension flow simulation is applied to analyze the flow in the cavity. The results of simulation correspond with experimental results. The cavity structure and the mold resin can be optimized by the simulation.

Conventional methods of physicochemical models require various experts and a high measurement demand to achieve the required model accuracy. With an additional request for faster development time for diagnostic algorithms, this method has reached the limits of economic feasibility. Machine learning algorithms are getting more popular in order to achieve a high model accuracy with an appropriate economical effort and allow to describe complex problems using statistical methods. An important point is the independence from other modelled variables and the exclusive use of sensor data and actuator settings. The concept has already been successfully proven in the field of modelling for exhaust gas aftertreatment sensors. An engine-out nitrogen oxide (NOX) emission sensor model based on polynomial regression was developed, trained, and transferred onto a conventional automotive electronic control unit (ECU) and also proves real-time capability.

Many ICs are used in various electronic components in automotive applications, such as ECUs (electronic control units) and smart actuators. Automotive ICs required the following features: (1) high integration of analog, digital and output devices; (2) high breakdown voltage for analog devices standing the battery voltage; (3) highly accurate control for analog circuits; (4) susceptibility under harsh operating conditions, such as high ambient temperature and high humidity; and (5) high surge immunity such as ESD (electrostatic discharge) robustness. To meet these requirements, we developed analog and output devices with improved surge endurance based on SOI wafer and trench-dielectric-isolation technologies. Analog circuit applications, especially accurate power management or high-precision solenoid driving, demands stable temperature-compensated output. Load dump and battery-jumping also needs high voltage protection and high noise immunity for these devices.

In Japan, from the viewpoint of ozone layer protection, specified CFCs (Chlorofluorocarbons) phase-out started in 1992 and completed by 1995. HFC-134a (Hydro fluorocarbon-134a) is now dominant in the market. HFC-134a, the replacement, has zero ozone depleting potential, while it still has a higher global warming potential (GWP = 1430). In this paper, efforts of DENSO and the Japanese industry from aspects of refrigerant emission reduction and energy efficiency improvement are introduced.

A lot of electric components have been installed in a vehicle today for comfort, safety and environment. This tendency is said to be continued in the future. Therefore, additional power supplies such as exhaust gas electricity generation system and thermal electricity generation system have been developed in the world to supply additional electricity as well as an enlargement of an alternator. However, if these new electricity supply systems are installed in a present electric power system that is controlled based on a voltage feedback, each supply system cannot be controlled effectively, because it is difficult to control output power of each system independently. An electric power based control system, Vehicle Electric power Flow management system (VEF), has been developed to avoid this problem. Sum of required electric power is calculated based on electric loads power and battery charging power. This required power is allocated to each power supply system.

Driving Automation Systems (DAS) are subject to complex road environments and vehicle behaviors and increasingly rely on sophisticated sensors and Artificial Intelligence (AI). These properties give rise to unique safety faults stemming from specification insufficiencies and technological performance limitations, where sensors and AI introduce errors that vary in magnitude and temporal patterns, posing potential safety risks. The Safety of the Intended Functionality (SOTIF) standard emerges as a promising framework for addressing these concerns, focusing on scenario-based analysis to identify hazardous behaviors and their causes. Although the current standard provides a basic cause-and-effect model and high-level process guidance, it lacks concepts required to identify and evaluate hazardous errors, especially within the context of AI. This paper introduces two key contributions to bridge this gap.

In general, automatic braking uses an electric stability control (ESC) hydraulic unit that can automatically increase the hydraulic pressure in the wheel cylinder (hereinafter called wheel pressure), independent of the driver’s braking operation. The hydraulic unit should have sufficient pressure response to apply autonomous emergency braking (AEB). It was necessary for the hydraulic unit to have a high flow rate for the pressure response. To satisfy the performance requirements of the AEB, a brushless motor, which has a high maximum rotational speed and good response, is adopted for the hydraulic unit. Furthermore, sensorless control, which does not require a rotation angle sensor, has been developed so that the motor size can be small and common to conventional units. The developed sensorless control can switch the driving methods in three states: pre-rotation, low speed, and high speed.