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Technical Paper

Vehicle electric power simulator for optimizing the electric charging system

2000-06-12
2000-05-0054
The electrical power system is the vital lifeline to most of the control systems on modern vehicles. The demands on the system are highly complex, and a detailed understanding of the system behavior is necessary both to the process of systems integration and to the economic design of a specific control system or actuator. The vehicle electric power system, which consists of two major components: a generator and a battery, has to provide numerous electrical and electronic systems with enough electrical energy. A detailed understanding of the characteristics of the electric power system, electrical load demands, and the driving environment such as road, season, and vehicle weight are required when the capacities of the generator and the battery are to be determined for a vehicle. An easy-to-use and inexpensive simulation program may be needed to avoid the over/under design problem of the electric power system. A vehicle electric power simulator is developed in this study.
Technical Paper

Real-Time Powertrain Control Strategy for Series-Parallel Hybrid Electric Vehicles

2007-08-05
2007-01-3472
The series-parallel hybrid electric vehicle(HEV), which employs a planetary gear set to combine one internal combustion engine(ICE) and two electric motors(EMs), can take advantages of both series and parallel hybrid system. The efficient powertrain operating point of the system can be obtained by the instantaneous optimization of equivalent fuel consumption. However, heavy computational requirements and variable constraints of the optimization process make it difficult to build real-time control strategy. To overcome the difficulty, this study suggests the control strategy which divides the optimization process into 2 stages. In the first stage, a target of charge/discharge power is determined based on equivalent fuel consumption, then in the second stage, an engine operating point is determined taking power transfer efficiency into account.
Technical Paper

Modeling of Pulse Width Modulation Pressure Control System for Automatic Transmission

2002-03-04
2002-01-1257
Generally, the widely used hydraulic control system in automatic transmissions is pulse width modulation (PWM) type. It consists in a PWM solenoid valve and a reducing type second stage valve, so called pressure control valve (PCV), to amplify pressure or flow rate. In this study, the mathematical models of the PWM solenoid valve and the PCV with moderate complexity are proposed. Then, their behavior is analyzed from the steady state characteristics. Finally, we find that there are good matches between the dynamic simulation results and the experimental data.
Technical Paper

Thermal Load in a Heavy Duty Diesel Engine with EUI System

2002-03-04
2002-01-0492
High pressure fuel injection systems, such as common rail (CR) systems and electronically-controlled unit injector (EUI) systems, have been widely applied to modern heavy duty diesel engines. They are shown to be very effective for achieving high power density with high fuel efficiency and low exhaust gas emissions. However, the increased peak combustion pressure gives additional structural stress and thermal load to engine structure. Thus, proper material selection and thermal analysis of engine components are essential in order to meet the durability requirements of heavy-duty diesel engines adopting a high pressure injection system. In this paper, thermal analysis of a 12.9 ℓ diesel engine with an EUI system was studied. Temperatures were measured on a cylinder head, a piston and a cylinder liner. A specially designed linkage system was used to measure the piston temperatures. A radio-tracer technique was also used to verify the rotation of piston rings.
Technical Paper

Scavenger free three-way catalyst with low hydrogen sulfide emission

2000-06-12
2000-05-0308
This study suggests new types of catalysts that show low hydrogen sulfide emission without scavenger such as NiO. Hydrogen sulfide can be reduced by changing the physicochemical properties of washcoat components. Synthesized gas activity tests were performed to investigate the effect of modified washcoat on hydrogen sulfide formation and catalytic activity. BET surface area tests, X- ray diffraction tests, and gas chromatography tests were also carried out to examine the characteristics of catalysts. Preparation methods for catalysts were focused on minimizing the adsorption of sulfur species on catalysts. The first approach is heat treatment of cerium oxide to reduce adsorption sites for sulfur compounds. But this leads to deterioration of CO and NOx conversion efficiencies. The second one is adding new types of promoters that increase thermal durability and dynamic oxygen storing function of cerium oxide.
Technical Paper

A throttle/brake control law for vehicle intelligent cruise control

2000-06-12
2000-05-0369
A throttle/brake control law for the intelligent cruise control (ICC) system has been proposed in this paper. The ICC system consists of a vehicle detection sensor, a controller and throttle/brake actuators. For the control of a throttle/brake system, we introduced a solenoid-valve-controlled electronic vacuum booster (EVB) and a step-motor-controlled throttle actuator. Nonlinear computer model for the electronic vacuum booster has been developed and the simulations were performed using a complete nonlinear vehicle model. The proposed control law in this paper consists of an algorithm that generates the desired acceleration/deceleration profile in an ICC situation, a throttle/brake switching logic and a throttle and brake control algorithm based on vehicle dynamics. The control performance has been investigated through computer simulations and experiments.
Technical Paper

The development of in-vehicle unit of advanced vehicle information and communication system

2000-06-12
2000-05-0370
This paper presents an in-vehicle information system, AVICS in development. With AVICS, the driver could get the various information on traffic, news, weather, restaurants, and so on, which the AVICS information center provides via mobile telecommunication network. The driver requests the information to operator in center by voice with hands-free system or by handling the menu offered in the form of web-page. The in-vehicle unit for AVICS is designed to interface with wireless network with a built-in RF MODEM, to control NAVI system, and to display the information on the LCD monitor of AV system. The Internet browser is customized to parse specific HTML tags, application software is realized on 32-bit RISC processor. In this paper, we will overview the concept of AVICS and focus on development of in-vehicle unit of AVICS.
Technical Paper

A study on Reducing the Computing Burden of Misfire Detection using a Conditional Monitoring Method

2004-03-08
2004-01-0722
This paper presents a conditional misfire monitoring method to reduce the computing burden of the motoring. In this conditional monitoring method, the ECU performs misfire detection only when there is high probability of misfire events. The condition for performing the misfire detection is determined by the pre-index which is defined as the deviation of the segment durations of the crankshaft in this paper. The quantity of the code of calculating the pre-index is 7 times less than that of a conventional monitoring method so that the computing burden can be reduced with the conditional monitoring method. The experimental results shown that the pre-index and the conditional monitoring method are valid.
Technical Paper

Vehicle Drift Investigation during Straight Line Accelerating and Braking

2008-04-14
2008-01-0588
A vehicle drifts due to several reasons from its intended straight path even in the case of no steering input. The multibody dynamic analysis of vehicle drift during accelerating and braking are performed. This paper focuses on modeling and evaluating effects of suspension parameters, differential friction, engine mounting and C.G. location of the vehicle under multibody dynamic simulation environment. Asymmetry of geometry and compliance between left and right side is considered cause of drift. The sensitivities of the suspension parameters are presented for each driving condition. In case of acceleration, the interaction of differential friction and driveshaft stiffness and their influence on drift are also studied. For braking condition, suspension parameters such as initial toe variation of rear coupled torsion beam axle type suspension and kingpin inclination deviation of front suspension are studied including the braking force difference.
Technical Paper

Powertrain-related vehicle sound development

2000-06-12
2000-05-0301
This paper reflects an efficient and comprehensive approach for vehicle sound optimization integrated into the entire development process. It shows the benefits of early consideration of typical vehicle NVH features and of intensive interaction of P/T and vehicle responsibilities. The process presented here considers the typical restriction that acoustically representative prototypes of engines and vehicles are not available simultaneously at the early development phase. For process optimization at this stage, a method for vehicle interior noise estimation is developed, which bases on measurements from the P/T test bench only, while the vehicle transfer behavior for airborne and structure-borne noise is assumed to be similar to a favorable existing vehicle. This method enables to start with the pre- optimization of the pure P/T and its components by focusing on such approaches which are mainly relevant for the vehicle interior noise.
Technical Paper

In search of SULEV-compliant THC emission reduction technologies

2000-06-12
2000-05-0298
This paper describes the development of THC reduction technologies compliant with SULEV regulations. Technologies embodied by the developmental work include improvement of fuel spay atomization, quick warm-up through coolant control shut off, and acceleration of fuel atomization for the fast rise of cylinder head temp inside the water jacket as well as the improvement of combustion state. The technologies likewise entail reduced HC while operating in lean A/F condition during engine warm-up with the cold lean-burn technology, individual cylinder A/F control for improvement of catalytic converting efficiency, aftertreatment such as thin-wall catalyst, HC absorber and EHC and etc., through vehicle application evaluation in cold start. We carried out an experimental as well as a practical study against SULEV regulations, and the feasibility of adopting these items in vehicle was likewise investigated.
Technical Paper

Automated Optimizing Calibration of Engine Driveability on the Dynamic Powertrain Test Bed

2013-10-14
2013-01-2588
Engine calibration on the powertrain test bed with transient mode is proposed with dynamic powertrain test bed having low inertia dynamometer. Automated ECU (Engine Control Unit) calibration system is completed with the combination of experimental design software, powertrain test bed, evaluation tools and their electrical interfaces. The process is composed up of the system interface definition, test design using DoE skill, test proceedings by step sequence of connecting systems, measured data collecting, mathematical model and optimization result extraction at the end. All the processes are automated by interfaces between the systems. Acceleration surge is minimized by proposed process by optimizing combustion control labels and tip in driveability is maximized by manipulating torque filter labels of EMS (Engine Management System) logic. Their detailed steps from the problem definition to the verification test results of improved design with vehicle test are presented.
Technical Paper

Analysis of Vehicle Voice Recognition Performance in Response to Background Noise and Gender Based Frequency

2017-06-05
2017-01-1888
Voice Recognition (VR) systems have become an integral part of the infotainment systems in the current automotive industry. However, its recognition rate is impacted by external factors such as vehicle cabin noise, road noise, and internal factors which are a function of the voice engine in the system itself. This paper analyzes the VR performance under the effect of two external factors, vehicle cabin noise and the speakers’ speech patterns based on gender. It also compares performance of mid-level sedans from different manufacturers.
Technical Paper

Synergies of Cooled External EGR, Water Injection, Miller Valve Events and Cylinder Deactivation for the Improvement of Fuel Economy on a Turbocharged-GDI Engine; Part 2, Engine Testing

2019-04-02
2019-01-0242
As CO2 legislation tightens, the next generation of turbocharged gasoline engines must meet stricter emissions targets combined with increased fuel efficiency standards. Recent studies have shown that the following technologies offer significant improvements to the efficiency of turbocharged GDI engines: Miller Cycle via late intake valve closing (LIVC), low pressure loop cooled EGR (LPL EGR), port water injection (PWI), and cylinder deactivation (CDA). While these efficiency-improving technologies are individually well-understood, in this study we directly compare these technologies to each other on the same engine at a range of operating conditions and over a range of compression ratios (CR). The technologies tested are applied to a boosted and direct injected (DI) gasoline engine and evaluated both individually and combined.
Technical Paper

Synergies of Cooled External EGR, Water Injection, Miller Valve Events and Cylinder Deactivation for the Improvement of Fuel Economy on a Turbocharged-GDI Engine; Part 1, Engine Simulation

2019-04-02
2019-01-0245
As CO2 legislation tightens, the next generation of turbocharged gasoline engines must meet stricter emissions targets combined with increased fuel efficiency standards. Promising technologies under consideration are: Miller Cycle via late intake valve closing (LIVC), low pressure loop cooled exhaust gas recirculation (LPL EGR), port water injection (PWI), and cylinder deactivation (CDA). While these efficiency improving options are well-understood individually, in this study we directly compare them to each other on the same engine at a range of operating conditions and over a range of compression ratios (CR). For this purpose we undertake a comprehensive simulation of the above technology options using a GT-Power model of the engine with a kinetics based knock combustion sub-model to optimize the fuel efficiency, taking into account the total in-cylinder dilution effects, due to internal and external EGR, on the combustion.
Technical Paper

Development of 4-Cylinder 2.0L Gasoline Engine Cooling System Using 3-D CAE

2019-04-02
2019-01-0156
To satisfy the global fuel economy restrictions getting stricter, various advanced cooling concepts, like active flow control strategy, cross-flow and fast warm-up, have been applied to the engine. Recently developed Hyundai’s next generation 4-cylinder 2.0L gasoline engine, also adopts several new cooling subsystems. This paper reviews how 3-D CAE analysis has been extensively used to evaluate cooling performance effectively from concept phase to pre-production phase. In the concept stage, the coolant flow in the water jacket of cylinder head and block was investigated to find out the best one among the proposed concepts and the further improvement of flow was also done by optimizing cylinder head gasket holes. Next, 3-D temperature simulation was conducted to satisfy the development criteria in the prototype stage before making initial test engines.
Technical Paper

A Study on Control Logic Design for Power Seat

2019-04-02
2019-01-0466
The large luxury sedan seat has a 22-way Movement. It offers a wide range of adjustments to enhance passenger comfort performance while it has many constraints on movement in constrained indoor space. In addition, the power seat is operated by a motor, which makes it difficult for the user to determine the amount of adjustment, unlike determining the amount of adjustment by the power and feel of a person, such as manual seat adjustment. IMS, one-touch mode, is also constrained by parameters such as indoor space package, user's lifestyle, etc. during function playback. This paper aims to design the seat control logic to achieve the best seat comfort while satisfying each constraint. The results of this study are as follows. Increase robustness of power seat control logic. Provide optimal adjustments and comfort at each location. Offer differentiated custom control and seating modes for each seat. Improve customer satisfaction and quality by upgrading software.
Technical Paper

In-Gear Slip Control Strategy of Dry-Clutch Systems Using a Sliding Mode Control

2019-04-02
2019-01-1305
This paper proposes a clutch control strategy during in-gear driving situations for Dual Clutch Transmissions (DCTs). The clutch is intentionally controlled to make small amount of a slip to identify the torque transfer capacity. The control objective of this phase is to ensure the clutch slip fairly remaining the specified value. To achieve this, the micro-slip controller is designed based on sliding mode control theory. Experimental verifications performed on onboard control system of the DCT equipped vehicle demonstrate that the proposed controller good tracking performance of the desired slip speed.
Technical Paper

Development of Adaptive Powertrain Control Utilizing ADAS and GPS

2019-04-02
2019-01-0883
This paper introduces the advancement of Engine Idle Stop-and-Go (ISG, also known as Auto Engine Stop-Start) and Neutral Coasting Control (NCC) with utilizing Advanced Driver Assistance System (ADAS) and GPS. The ISG and the In-Neutral Coasting (also known as Sailing or Gliding) have been widely implemented in recent vehicles for improving their fuel economy. However, many drivers find them somewhat disturbing because they basically change behaviors of their cars from what they used to. This annoyance discourages usages of those functions and eventually undermines their benefit of fuel saving. In order to mitigate the problem, new ISG and NCC algorithms are proposed. As opposed to the conventional logics that rely only on driver’s pedal action, the new algorithms determine whether or not to enable those functions for the given driving condition, based on the traffic information obtained using ADAS sensors and the location data from GPS and navigation map.
Technical Paper

Study on Optimization for LNT+SCR System of Diesel Vehicle to Comply with the LEV3 Regulations

2014-04-01
2014-01-1529
This paper describes how to meet LEVII ULEV70 emission standards and minimize fuel consumption with the combined NOx after-treatment (LNT+SCR) system for diesel vehicles. Through analysis of LNT's functionality and characteristics in a LNT+SCR combined after-treatment system, allowed a new control strategy to be established, different from the existing LNT-only system. In the 200°C or higher condition where SCR can provide the most stable NOx conversion efficiency, rich regeneration of LNT was optimized to minimize LNT deterioration and fuel consumption. Optimized mapping between rapid heat up strategy and raw NOx reduction maximized LNT's NOx conversion efficiency during the intervals when it is not possible for SCR to purify NOx This study used bench aged catalysts which were equivalent to 150K full useful life.
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