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Technical Paper

Development of High Accuracy Rear A/F Sensor

2017-03-28
2017-01-0949
New 2A/F systems different from usual A/F-O2 systems are being developed to cope with strict regulation of exhaust gas. In the 2A/F systems, 2A/F sensors are equipped in front and rear of a three-way catalyst. The A/F-O2 systems are ideas which use a rear O2 to detect exhaust gas leaked from three-way catalyst early and feed back. On the other hand, the 2A/F systems are ideas which use a rear A/F sensor to detect nearly stoichiometric gas discharged from the three-way catalyst accurately, and to prevent leakage of exhaust gas from the three-way catalyst. Therefore, accurate detection of nearly stoichiometric gas by the rear A/F sensor is the most importrant for the 2A/F systems. In general, the A/F sensors can be classified into two types, so called, one-cell type and two-cell type. Because the one-cell type A/F sensors don’t have hysteresis, they have potential for higher accuracy.
Technical Paper

Mitigating Unknown Cybersecurity Threats in Performance Constrained Electronic Control Units

2018-04-03
2018-01-0016
Externally-connected Electronic Control Units (ECUs) contain millions of lines of code, which may contain security vulnerabilities. Hackers may exploit these vulnerabilities to gain code execution privileges, which affect public safety. Traditional Cybersecurity solutions fall short in meeting automotive ECU constraints such as zero false positives, intermittent connectivity, and low performance impact. A desirable solution would be deterministic, require minimum resources, and protect against known and unknown security threats. We integrated Autonomous Security on a BeagleBone Black (BBB) system to evaluate the feasibility of mitigating Cybersecurity risks against potential threats. We identified key metrics that should be measured, such as level of security, ease of integration and system performance impact. In this paper, we describe the integration and evaluation process and present its results.
Technical Paper

Accumulation Mechanism of Gasoline EGR Deposit

2017-03-28
2017-01-0806
Exhaust Gas Recirculation (EGR) systems reduce exhaust emissions and improve fuel efficiency. Recently, the number of EGR system installed vehicles has been increasing, especially for gasoline engine systems. One of the major causes of decreasing EGR function is deposit accumulation on a gas passage. The deposit consists mainly of hydrocarbons which are degradation products of fuel, thus the amount of deposit seems to be strongly affected by fuel compositions. Unfortunately there are not as many studies on EGR deposits with gasoline fuel as there are with diesel fuel. In this study, the influence of gasoline fuel compositions, especially aromatics which are major components of EGR gas, on chemical structures of the deposit were investigated. To clarify the accumulation mechanism of EGR deposits, a thermal oxidative degradation test with an autoclave unit and an actual gasoline engine test were employed.
Technical Paper

Development of the Large Type Electric-Driven Refrigerator for the HV Truck

2017-03-28
2017-01-0137
In respect to the present large refrigerator trucks, sub-engine type is the main product, but the basic structure does not change greatly since the introduction for around 50 years. A sub-engine type uses an industrial engine to drive the compressor, and the environmental correspondence such as the fuel consumption, the emission is late remarkably. In addition, most of trucks carry the truck equipment including the refrigerator which consumes fuel about 20% of whole vehicle. Focusing on this point, the following are the reports about the system development plan for fuel consumption reduction of the large size refrigerator truck. New concept is to utilize electrical power from HV system to power the electric-driven refrigerator. We have developed a fully electric-driven refrigerator system, which uses regenerated energy that is dedicated for our refrigerator system.
Technical Paper

Diesel Powertrain Energy Management via thermal Management and Electrification

2017-03-28
2017-01-0156
The coming Diesel powertrains will remain as key technology in Europe to achieve the stringent 2025 CO2 emission targets. Especially for applications which are unlikely to be powered by pure EV technology like Light Duty vehicles and C/D segment vehicles which require a long driving range this is the case. To cope with these low CO2 targets the amount of electrification e.g. in form of 48V Belt-driven integrated Starter Generator (BSG) systems will increase. On the other hand the efficiency of the Diesel engine will increase which will result in lower exhaust gas temperatures resulting in a challenge to keep the required NOx reduction system efficiencies under Real Drive Emissions (RDE) driving conditions. In order to comply with the RDE legislation down to -7 °C ambient an efficient thermal management is one potential approach. Commonly utilized means to increase exhaust gas temperature are late injection and/or intake throttling, which enable sufficient NOx reduction efficiency.
Technical Paper

A Novel Beamspace Technology Based On 2FCW for Radar Target Detection

2017-03-28
2017-01-0025
In the last decade, radar-based Advanced Driver Assistance Systems (ADAS) have improved safety of transportation. Today, the standardization of ADAS established by New Car Assessment Program (NCAP) is expected to expand its market globally. One of the key technologies of ADAS is the rear-side monitoring system such as Blind Spot Warning (BSW) and Closing Vehicle Warning (CVW). It is required to expand its detection range so that it can monitor not only nearside targets for BSW, but farther targets for CVW. These applications can be achieved using two radar sensors installed at rear-side corner of the vehicle. However, the expanded detection range causes undesirable target detections and decreases target recognition performance. In this paper, a novel solution to improve the performance using DCMP(Directional-Constrained Minimization of Power)-based Beamspace technology using Two-frequency continuous wave (2FCW also known as FSK) is introduced.
Journal Article

Prediction Method for Automobile EMI Test Result in AM Frequency Band

2017-03-28
2017-01-0014
The EMI, electromagnetic interference, is tested for automobiles and components by the method defined in the international standard, CISPR 25. Regarding the automobile test, the EMI from the component installed in the automobile is measured by the antenna of an automobile. On the other hand on the component test, the EMI from the component is measured by a mono-pole antenna set forward of the component. However, components sometimes fail the automobile test even if its passed the component test due to the difference of the method. In this case, the component has to be designed again to pass the automobile test. Therefore, the prediction method of the automobile test result is required. In this paper, we tried to modify the standard component test configuration to predict the automobile test result for a fuel pump system in AM frequency band.
Technical Paper

Criteria-Driven Approach in Automotive Software Development – Integrating Concepts of Formal Methods with Testing

2017-03-28
2017-01-0003
We propose a verification method in the field of automotive control systems integrating the concepts of Formal Methods with testing, aiming at efficient and reliable software development. Although Formal Methods are believed to provide the benefits of their rigorous nature and their inherent capability of automation, only limited cases are known where Formal Methods were applied in system and software development, in practice, due to two major difficulties: appropriate abstraction in modeling and scalability in automated reasoning. Focusing on testing on the other hand, there is the difficulty of selecting reasonable set of tests for given verification objectives. In order to overcome these difficulties, our approach is to present verification criteria for testing to appropriately cover the property with the help of the Formal Method concepts.
Journal Article

Capacitive Humidity Sensors Using Highly Durable Polyimide Membrane

2013-04-08
2013-01-1337
Humidity sensors used in automatic windshield defogging controls contribute to the improvement of fuel consumption. The optimum control of air conditioning systems can be realized by adding humidity information to conventional systems which have used only temperature information. While resistive humidity sensors have been widely used, their sensing range and responsiveness are observed as issues. Resistive sensors cannot function at a humidity range of around 100% RH as well as at a low temperature range, and have a low response rate to sudden changes in humidity. It is considered that resistive humidity sensors will be replaced with capacitive ones which have a wide sensing range and high responsiveness.
Journal Article

Design of Seat Mounted ECG Sensor System for Vehicle Application

2013-04-08
2013-01-1339
The causes of deaths in traffic accidents are predominantly human factors such as careless or "heedlessness" driving; recently, accidents that are believed to be due to deteriorated physical conditions, such as heart attacks, have been reported. Non-contact electrocardiography (ECG) monitor for continuous ECG detection while driving is needed to reduce a number of fatal accident by human error like this. Recently there are a lot of papers to detect cardiac electricity using capacitance coupling between human body and electrode. This sensor system must be adopted appropriate high input impedance circuit and noise reduction technique as a function of source impedance value especially for a seat mounted sensor.
Journal Article

Artist-Centric New HMI Software Development Workflow: Development of Real-Time 3D Rendering Engine for Reconfigurable Instrument Clusters

2013-04-08
2013-01-0425
Instrument clusters that display all information on a TFT-LCD screen, also known as reconfigurable instrument clusters, have become the new trend in automotive interiors. DENSO mass-produced the world's first reconfigurable instrument cluster in 2008. To satisfy customer requirements, large quantities of resources were required. Coupled with an iterative process due to requirement changes, development costs became very high. Reducing development costs was vital in order to expand the reconfigurable instrument cluster products line. One solution was to use existing human machine interface (HMI) tools. However, most HMI tools are geared toward software developers and not graphic artists. Furthermore, each tool has its own unique method for image and scene creation, creating an ineffective and sometimes difficult environment for artists familiar with industry-leading computer graphics (CG) software to learn and use the tools.
Journal Article

2-Drive Motor Control Unit for Electric Power Steering

2017-03-28
2017-01-1485
The electric power steering (EPS) is increasing its number since there are many advantages compared to hydraulic power steering. The EPS saves fuel and eliminates hydraulic fluid. Also, it is more suitable to the cooperation control with the other vehicle components. The EPS is now expanding to the heavier vehicle with the advance in the power electronics. In order to meet customer's needs, such as down-sizing, lower failure rate and lower price, we have developed the new motor control unit (MCU) for the EPS. The motor and the electric control unit (ECU) were integrated for the better installation. We adopted new technologies of redundant 2-drive design for more safe EPS. “2-drive Motor Control technology” which consists of dual winding, two torque sensors and two inverter drive units. In our developed MCU, even if there is a failure in one of the drive unit, the assistance of the EPS can be maintained with the other drive unit.
Journal Article

Non-Contact Measurement Method for High Frequency Impedance of Load at the End of Wire Harness

2017-03-28
2017-01-1643
To avoid a trial and error adjustment for designing EMI filters, clarifying load impedance of operating condition, i.e., dynamic impedance of equipment is very useful. Therefore the need to a non-contact measurement method of the impedance connected to a wire harness is increasing rapidly. A measurement method using a network analyzer with two current probes was previously proposed. However, it was confirmed only up to 30 MHz. Many radio equipment operate above 30 MHz such as FM receivers and GPS receivers installed in vehicles. So increasing the measurement frequency is necessary in the auto industry. At first, we tried to expand the applicable frequency to 100 MHz, i.e., FM band. In this study, we applied the transmission line theory using the non-contact measurement method. Furthermore, in order to use the theory, the characteristic impedance and phase constant of the wire harness are required. So we made an additional measurement to estimate them.
Journal Article

Reduction of Cranking Noise from High Voltage Starter for One-Motor Two-Clutch Hybrid Systems

2017-03-28
2017-01-1167
In this paper, we propose a high voltage brushless AC starter that contributes to improved fuel efficiency and a reduction in the cost of the one-motor two-clutch hybrid system, which we call a 1MG2CL system. We have named it the HV starter, and it is composed of an AC motor, inverter and pinion with a shift mechanism. One of the issues with the 1MG2CL system is the high electrical energy when starting an ICE as it switches over from EV drive to HEV drive. While the ICE is starting, the main motor has to crank the ICE via the clutch; the clutch slips to absorb the main motor power, so the main motor has to output a high power to overcome the loss. Therefore, to contribute to reducing the electrical power by eliminating clutch slip losses, we developed an HV starter as a dedicated ICE starting device. Thanks to the reduction in electrical power, the HV starter is able to improve fuel efficiency and reduce system costs.
Journal Article

Self-Excited Wound-Field Synchronous Motors for xEV

2017-03-28
2017-01-1249
Compact, high efficiency and high reliability are required for an xEV motor generator. IPM rotors with neodymium magnets are widely applied for xEV motors to achieve these requirements. However, neodymium magnet material has a big impact on motor cost and there is supply chain risk due to increased usage of these rare earth materials for future automotive xEV’s. On the other hand, a wound-field rotor does not need magnets and can achieve equivalent performance to an IPM rotor. However, brushes are required in order to supply current to the winding coil of the rotor. This may cause insulation issues on xEV motors which utilize high voltage and high currents. Therefore, it is suggested to develop a system which supplies electric energy to the rotor field winding coil from the stator without brushes by applying a transformer between stator coil and rotor field winding. Specifically, add auxiliary magnetic poles between each field winding pole and wind sub-coils to these poles.
Technical Paper

Numerical Modeling of International Variations in Diesel Spray Combustion with Evaporation Surrogate and Virtual Species Conversion

2017-03-28
2017-01-0582
A methodology for simulating effect of international variations in fuel compositions on spray combustion is proposed. The methodology is validated with spray combustion experiments with real fuels from three different countries. The compositions of those fuels were analyzed through GC×GC and H-NMR. It was found that ignition delay times, flame region and flame luminosity were significantly affected by the compositional variations. For the simulation, an evaporation surrogate consisting of twenty two species, covering basic molecular types and a wide range of carbon numbers, is developed. Each species in the evaporation surrogate is then virtually converted to a reaction surrogate consisting of n-hexadecane, methylcyclohexane and 1,2,4-trimethyl benzene so that combustion reactions can be calculated with a published kinetic model. The virtual species conversion (VSC) is made so as to take over combustion-related properties of each species of evaporation surrogates.
Technical Paper

IGBT Gate Control Methods to Reduce Electrical Power Losses of Hybrid Vehicles

2016-04-05
2016-01-1224
Reducing the loss of the power control unit (PCU) in a hybrid vehicle (HV) is an important part of improving HV fuel efficiency. Furthermore the loss of power devices (insulated gate bipolar transistors (IGBTs) and diodes) used in the PCU must be reduced since this amounts to approximately 20% of the total electrical loss in an HV. One of the issues for reducing loss is the trade-off relationship with reducing voltage surge. To restrict voltage surge, it is necessary to slow down the switching speed of the IGBT. In contrast, the loss reduction requires the high speed switching. One widely known method to improve this trade-off relationship is to increase the gate voltage in two stages. However, accurate and high-speed operation of the IGBT gate control circuit is difficult to accomplish. This research clarifies a better condition of the two-stage control and designed a circuit that improves this trade-off relationship by increasing the speed of feedback control.
Technical Paper

Analysis of Influence Factors for Partial Discharge Inception Voltage between Magnet-Wires on Rotating Machines

2016-04-05
2016-01-1226
In automobiles, Integrated Starter Generators (ISGs) are important components since they ensure significant fuel economy improvements. With motors that operate at high voltage such as ISGs, it is important to accurately know partial discharge inception voltages (PDIVs) for the assured insulation reliability of the motors. However, the PDIVs vary due to various factors including the environment (temperature, atmospheric pressure and humidity), materials (water absorption and degradation) and voltage waveforms. Consequently, it is not easy either empirically or analytically to ascertain the PDIVs in a complex environment (involving, for example, high temperature, low atmospheric pressure and high humidity) in which many factors vary simultaneously, as with invehicle environments. As a well-known method, PDIVs can be analyzed in terms of two voltage values, which are the breakdown voltage of the air (called “Paschen curve”) and the shared voltage of the air layer.
Journal Article

Approaches for Secure and Efficient In-Vehicle Key Management

2016-04-05
2016-01-0070
Modern vehicles utilize various functionalities that require security solutions such as secure in-vehicle communication and ECU authentication. Cryptographic keys are the basis for such security solutions. We propose two approaches for secure and efficient invehicle key management. In both approaches, an ECU acting as a Key Master in the vehicle is required. The first approach is based on SHE. The Key Master generates and distributes new keys to all ECU based on the SHE key update protocol. The second approach performs key establishment based on key derivation. The Key Master sends a trigger in form of a counter and all ECUs derive new keys based on the received counter value and pre-shared keys. It is thus possible to handle in-vehicle key management without the need for an OEM backend to manage all keys. This reduces cost and complexity of the solution.
Journal Article

Multiplex Communication Protocol for Switch/Sensor/Actuator Network: “CXPI”

2016-04-05
2016-01-0057
The growing functionality and complexity of recent vehicle electronic systems have made inter-device communication (on-board LAN) technology vital to vehicle design. By field of application, the LAN (Local Area Network) systems currently in use are LIN (Local Interconnect Network) used for body systems, CAN (Controller Area Network) used for control systems, and MOST (Media Oriented Systems Transport ) used for multimedia and camera systems, and work to standardize the next-generation communication technology for each of those fields is underway. This paper provides a technical overview of the CXPI (Clock Extension Peripheral Interface) communication protocol, which satisfies the body system requirements (rapid response, system extensibility, high reliability, and low cost). It also presents the progress made on standardization at SAE and other organizations.
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