Wootaik Lee

AUTOSAR-ready Light Software Architecture for Automotive Embedded Control Systems

This paper presents AUTOSAR-ready light software architecture (AUTOSAR-Lite), which is a light weighted version of the AUTOSAR, for automotive embedded control systems. The proposed AUTOSAR-Lite reduces overhead problems caused by the excessive standard specifications of AUTOSAR. Concurrently, AUTOSAR-Lite keeps advantages of AUTOSAR such as a scalability, re-usability, reliability, and transferability. The fundamental design of AUTOSAR-Lite is originated from the AUTOSAR standard. AUTOSAR-Lite is composed of three layers such as an application software, runtime environment, and basic software layer. The application software layer adopts component-based design methodology as AUTOSAR. The runtime environment layer integrates interfaces between application and basic software layers. In case of the basic software layer, restrictions of the module configurations and interfaces of basic software are minimized. In order to validate the feasibility of AUTOSAR-Lite, a software design result based on AUTOSAR-Lite software architecture for electronic throttle control (ETC) system is suggested.

Application Software Modeling and Integration Methodology using AUTOSAR-ready Light Software Architecture

This paper describes a model-based software development methodology for AUTOSAR-ready light software architecture(AUTOSAR-Lite). The proposed methodology briefly represents an application software modeling technique using Matlab/Simulink. Using the proposed technique, application software architecture elements (e.g. software components, runnables, and interfaces) and functional behaviors can be designed in a single modeling environment. From the designed model, the codes of application software is automatically generated using Real-Time Workshop Embedded Coder. The generated application software is easily integrated with hand-coded basic software using the proposed method. In order to evaluate the proposed methodology, a diesel engine management system for a passenger car was employed as a case study. Based on the methodology, 8 atomic software components and 52 runnables are successfully developed, and they are evaluated by engine experiments. From this case study, AUTOSAR compatible model-based application software was successfully developed, and the effectiveness of the proposed methodology was evaluated.

Stoichiometry dependence of electrochemical performance of thin-film SnOx microbattery anodes deposited by radio frequency magnetron sputtering

Thin-film SnOx microbattery anodes, with various oxygen deficiencies, are deposited from a SnO2 target on to an ambient temperature substrate by radio frequency (RF) magnetron sputtering. The high reversible capacity and cycle performance characteristics of SnOx are described. RF power density and process gas pressure during deposition are fixed at 2.5 W/cm2 and 10 mTorr, respectively. The SnOx films are characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Constant-current galvanostatic charge–discharge tests of half cells are also performed. The stoichiometric parameter x increases with the increase in oxygen partial pressure, but decreases when the number of Sn chips placed on the target material in an argon atmosphere are increased. It is observed that SnOx transforms to lithium oxide and metallic Sn after an initial Li intercalation reaction. The charge–discharge performance of the tin oxide films is found to be dependent on stoichiometry. In the present work, SnO1.43 is the optimum stoichiometry, exhibiting the highest reversible capacity (498.33 μA h/cm2 μm) and the lowest irreversible capacity (301.79 μA h/cm2 μm).

Target-identical rapid control prototyping platform for model-based engine control

Abstract Rapid control prototyping (RCP) is one of the most important technologies for speeding up the development process of the electronic control unit (ECU) used in the automotive control system. However, one big drawback of the conventional RCP platform is the transfer from RCP to target ECU implementation. In this study, a new RCP platform is proposed that provides a consistent environment for both the RCP development stage and the target ECU implementation stage. In order to make the rapid prototyping controller as similar to a production ECU as possible, the prototyping system follows the strictly layered architecture of the production ECU and separates the automatically generated code of software from the hand code. Finally, the feasibility of the developed target-identical RCP platform is evaluated through an air-to-fuel ratio (AFR) control application.

Development of a Vehicle Electric Power Simulator for Optimizing the Electric Charging System

The vehicle electric power system, which consists of two major components: a generator and a battery, which have 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 is 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. The simulator can be utilized to determine the optimal capacities of generators and batteries. To improve the expandability and easy usage of the simulation program, the program is organized in modular structures, and is run on a PC. Empirical electrical models of various generators and batteries, and the structure of the simulation program are presented. For executing the vehicle electric power simulator, data of engine speed profile and electric loads of a vehicle are required, and these data are obtained from real driving conditions. In order to improve the accuracy of the simulator, numerous driving data of a vehicle are logged and analyzed.

Dead Time Compensation and Polarity Check of Phase Currents Based on Programmable Low-pass Filter for Automotive Electric Drive Systems

Abstract : This paper proposes a dead time compensation method for an AC motor drive using phase current polarity information which is detected based on a digital programmable low-pass filter (PLPF). The polarity detection using the PLPF is an alternative solution of a conventional method which uses a general low-pass filter (LPF) and hysteresis bands in order to avoid jittering due to noises. The PLPF not only adjusts its cutoff frequency according to the synchronous frequency of AC motors but also eliminates a gain attenuation and phase delay which are main problems of the general LPF. Through the PLPF, a fundamental component signal without gain and phase distortions is extracted from the measured raw current signal with noise. By use of the fundamental component, the polarity of current is effectively detected by reducing the hysteresis band. Finally, the proposed method compensates the dead time effects by adding or subtracting average voltage value to voltage references of the controller according to the detected current polarity infor-mation. The proposed compensation method is experimentally verified by compared with the conventional method.