A Study on the Development of Accelerated Life Test Method Considering Thermal Fatigue of Automotive Electronic Control Unit

김태경(Tae Kyung Kim),이정환(Jung Hwan Lee) Korean Society for Precision Engineering 2022 한국정밀공학회지 Vol.39 No.11

The automotive electronic control unit outputs control signals using electrical signals of various input sensors installed in the vehicle to control the state of the engine, automatic transmission, and electric power steering (EPS). These units are installed inside the vehicle or engine room, and the temperature rises and falls by several tens of degrees due to the heat of the engine and the self-heating of the electronic control unit. Therefore, it was exposed to a thermal fatigue environment due to the difference in the coefficient of thermal expansion between the components, which caused frequent component damage. Solder cracks due to thermal fatigue in electronic control units are a key failure mode. However, because of its great heat capacity, the electronic control unit for automobiles took a long time to attain the desired temperature of high or low, and as a result, the 1,000-cycle test for thermal fatigue life verification required 3,167 hours (or 4.4 months). Therefore, in this study, the thermal shock cycle test time for the verification of the thermal fatigue life of electronic control units for automobiles was reduced by dividing it into two types.

Variable structure controller design for steer-by-wire system of a passenger car

Iman Mousavinejad,Reza Kazemi 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.8

The electric power steering (EPS) system was developed and the steer-by-wire (SBW) system achieves the purposes of EPS. The advantagesof SBW are packaging flexibility, advanced vehicle control system, and superior performance. No mechanical linkage existsbetween the steering gear and steering column in the SBW system. The steering wheel and front-wheel steering can be controlled independently. The SBW system consists of two motors controlled by an electronic control unit (ECU). One motor is in the steering wheeland develops the steering feel of the driver and the other motor is in the steering linkage and improves vehicle maneuverability and stability. Moreover, the active front steering (AFS) system can be added to the SBW system. AFS reduces the difference between actual andestimated vehicle yaw rate. Up-to-date information from the steering wheel enables drivers to identify road conditions through the tireforce, which should be fed back to the steering wheel. Furthermore, several control algorithms related to the vehicle and motor can beused together through the self-aligning torque, which is fed back to the steering wheel. This study proposes a method to control the vehicleyaw rate through an SBW system. This control method is based on a PID control method for the steering-wheel-motor controller, aswell as on a sliding mode control (SMC) method for the front-wheel-motor controller and yaw stability controller. The SBW system ismodeled using a bond graph method. Results imply that the controllers are robust enough when in contact with nonlinear properties oftire and road conditions. This study is expected to guide further research on the SBW system.

32-bit 임베디드 시스템을 이용한 자동변속기용 전자제어시스템의 Software-in-the-loop simulation

장인규(In-Gyu Jang),서인근(Inkeun Seo),전재욱(Jaewook Jeon),황성호(Sung-Ho Hwang) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Drivers are becoming more fatigued and uncomfortable as traffic densities increase, which can lead to slower reaction time, They then face the danger of traffic accidents due to an inability to cope with frequent shifting, To reduce this risk some drivers prefer automatic transmissions (AT) to manual transmissions (MT), The AT is superior drivability and less shifting shock than the MT, so the market-share of AT is increasing, The AT is controlled by Electronic Control Unit (ECU) to obtain better shifting performance, The Transmission Control Unit (TCU) is a product of higher-value-added, so the companies which have advanced technology (BOSCH, SIEMENS VDO, DELPHI, and etc.) tend to evade technology transfer. As the number of ECU used on a car is increasing gradually (for example, engine management unit, transmission control unit, brake control unit, and powertrain control unit), TCU's performance is expected to be faster and more efficient for organic communication and arithmetic processing between the control systems than the performance of 16bit controller. In this paper, the model of automatic transmission vehicle using MATLAB/Simulink is developed for the hardware in-the-loop simulation with an embedded system. The AT control logic developed is loaded to 32-bit Embedded system platform developed on the basis of Freescale's MPC565, and we execute the Software-in-the-loop simulation (SILS) of AT based on Real Time Operating System (RTOS). These test results show that the developed embedded system can be used as AT control unit.

전기이륜차 기능 안전 컨셉 설계에 대한 고찰

곽인재(Injae Kwak),김상훈(SangHoon Kim),노형태(HyeongTae Noh) 한국자동차공학회 2023 한국자동차공학회 학술대회 및 전시회 Vol.2023 No.11

Electrical two wheeler have become familiar in our daily life world widely these days to reduce a carbon emission and global warming issue. ISO 26262 is an international standard for functional safety in the automotive industry. The standard applies to electrical and electronic systems consisting of hardware and software components in vehicles and development process to maintain vehicle lifecycle. This topic have been highly recommended on the electrical two wheeler to avoid hazard of the high voltage system to protect driver and pedestrian but also for the safety on the system. The framework of functional safety should need to duplexing design on the hardware to monitor system conditions. In this paper, we have focus on the concept design of functional safety for the conventional electrical two wheeler system with application software in vehicle control unit. The control of vehicle behavior and coordination control with other control units through brake and throttle signal and several digital switches. This study is the first step of functional safety system for the electrical two wheeler.

Design of Controllers for the Stable Idle Speed in the Internal Combustion Engine

Lee, Young-Choon Korean Society for Precision Engineering 2001 International Journal of the Korean Society of Pre Vol.2 No.4

This paper deals with control design method having anticipation delay which is proposed for the discrete nonlinear engine where system dynamics is not accurate. Due to the induction-to-power delay in internal combustion(IC) engine having abrupt torque loss, underdamping and chattering in engine idle speed becomes a serious problem and it could make drivers uncomfortable. For this reason, Three types of the closed-loop controller are developed for the stable engine idle speed control. The inputs of the controllers are an engine idle speed and air conditioning signal. The output of the controllers is an duty cycle to operate the idle speed control valve(ISCV). The proposed controllers will be useful for improving actual vehicles since these shows good test

임베디드 시스템을 이용한 CVT의 변속제어 특성 연구

한기원(Kiwon Han),류완식(Wansik Ryu),장인규(In-Gyu Jang),전재욱(Jaewook Jeon),김현수(Hyunsoo Kim),황성호(Sungho Hwang) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The continuously variable transmission (CVT), to implement speed ratio infinitely in the fixed range, has the characteristic of low fuel consumption and low exhaust gas due to operating the vehicle in a high efficiency range without concerning between engine speed and vehicle speed. The speed ratio of belt type CVT is controlled by adjusting line pressure. The line pressure control prevents slip between the pulley and the belt by conserving optimal line pressure, which is implemented by controlling the thrust force of actuators of both the drive-shaft and the driven-shaft. The one of the line pressure control methods, mechanical-hydraulic control is usually adopting VDT's control method, in which the secondary solenoid valve has two functions both a regulator and a line pressure controller. However, this control method could not show the high performance of CVT with optimal driving capability because of the limitation of simple control algorithm, and it could not gain market share sufficiently in spite of the advantage of CVT with low fuel consumption. On the other hand, the electro-hydraulic control method gives the enhancement of power performance and low fuel consumption by implementing various driving mode using the proportional control or PWM control. The key of CVT technique is to develop a control algorithm of the electro-hydraulic solenoid valve in order to implement the speed ratio efficiently. In this paper, the line pressure control algorithm is proposed and the speed control characteristic is validated using metal belt type CVT test rig and the embedded ECU platform.

자동변속기용 임베디드 시스템 성능 시험을 위한 Hardware-in-the-Loop 시뮬레이터 구축

장인규(In-Gyu Jang),서인근(Inkeun Seo),전재욱(Jaewook Jeon),황성호(Sung-Ho Hwang) 제어로봇시스템학회 2008 제어·로봇·시스템학회 논문지 Vol.14 No.3

Drivers are becoming more fatigued and uncomfortable with increase in traffic density, and this condition can lead to slower reaction time. Consequently, they may face the danger of traffic accidents due to their inability to cope with frequent gear shifting. To reduce this risk, some drivers prefer automatic transmission (AT) over manual transmission (MT). The AT offers more superior drivability and less shifting shock than the MT; therefore, the AT market share has been increasing. The AT is controlled by an electronic control unit (ECU), which provides better shifting performance. The transmission control unit (TCU) is a higher-value-added product, so the companies that have advanced technologies end to evade technology transfer. With more cars gradually using the ECU, the TCU is expected to be faster and more efficient for organic communication and arithmetic processing between the control systems than the l6-bit controller. In this paper, the model of an automatic transmission vehicle using MATLAB/Simulink is developed for the Hardware in-the-Loop (HIL) simulation with a 32-bit embedded system, and also the AT control logic for shifting is developed by using MATLAB/Simulink. The developed AT control logic, transformed automatically by real time workshop toolbox, is loaded to a 32-bit embedded system platform based on Freescale"s MPC565. With both vehicle model and 32-bit embedded system platform, we make the HIL simulation system and HIL simulation of AT based on real time operating system (RTOS) is performed. According to the simulation results, the developed HIL simulator will be used for the performance test of embedded system for AT with low cost and effort.

비동기 이중화 시스템의 센서 SENT protocol 신호 간 단락 고장 검출 알고리즘에 관한 사례 연구

서동균(Dongkyun Seo),황대훈(Daehun Hwang) 한국자동차공학회 2022 한국자동차공학회 부문종합 학술대회 Vol.2022 No.6

In a redundant distributed system due to functional safety, etc., the physical distance between controllers may be very close. If the physical distance is close, there is a high possibility of interference between the controller and the connected sensor signal line. To prevent this, SAE J2716 SENT (Single Edge Nibble Transmission) is used, but when a short circuit occurs between physical lines, there is a case where the failure cannot be detected. In this case, an erroneous signal may be transmitted to the controller and pose a risk to the driver. To solve this problem, this paper describes a case study for detecting a failure when a physical short circuit occurs in each controller sensor signal line for the SENT signal of the sensor used in the asynchronous redundant vehicle distributed system controller.

양산 적용을 고려한 래피드 프로토타이핑 플랫폼 기반의 전자 스로틀 제어기 개발

박일수(Ilsu Park),박성민(Seongmin Park),김성근(Sungkun Kim) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

A rapid prototyping is one of the most economical techniques which shorten the development cycle of the control system. It is easy to design and simulate the controller. But the automotive company must pay attention to production as well as design. Therefore, the automotive software developers need the platform which enables seamless development from concept to production level codes. This paper describes the platform which has the structure with hardware-specific layers and hardware-independent layers. The development of electronic throttle controller will be introduced as a practical application based on this platform.

자동차 전장제품의 무연솔더 적용기술 및 솔더 접합부 열화거동

홍원식,오철민,Hong, Won Sik,Oh, Chul Min 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.3

Due to ELV banning, automotive electronics cannot use four kinds of heavy metal element (Pb, Hg, Cd, $Cr^{6+}$) from 2016. Therefore, this study was focused on degradation characteristics of Sn-3.0Ag-0.5Cu Lead-free solder joint with OSP and ENIG finsh under various reliability assessment method, as like to thermal shock test and high temeprature/high humidity test with test duration for cabin electronics. Also, we compared bonding strength degradation to other advanced research results of electronic control unit for engine room because of difference service temperature with mount location in automotive. Whisker growth phenomenon and mitigation method which were essentially consideration items for Pb-free car electronics were examined. Conformal coating is a strong candidate for mitigating whisker growth in automotive electronics. Necessary condition to adapt Pb-free in car electronics was shown.