• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.432-437
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• 2017

As 4.0 industry has been developed, research on a self-driving car technology and related parts of an automobile has been highly investigated recently. Particularly, a TAS(Torque Angle Sensor) module on steering wheel system has been considered as a key technology because of its precise angle, torque detection and high speed signal processing. The environmental assessment is generally required on the TAS module to examine high resolution of angle/torque detection. In the case of existing TAS module, angle detection errors has been occurred by back-lash on main and sub gear in addition to complicated structure caused by gears. In this paper, a structure of the TAS module, which minimizes the numbers of components and angle detection errors on the module compared with the existing TAS module, for vehicle steering system based on a Multi-track Encoder has been proposed. Also, angle detection signal processing board, and key technology of the TAS module were fabricated and evaluated. As a result of the experiments, we confirmed an excellent performance of the fabricated signal processing board for angle detection and an applicability of the fabricated angle detection board on the TAS module of vehicles by the environmental assessment an automobile standard.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.72-81
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• 2013

Many articles have been published about a 2-degree of freedom model that includes the lateral and yaw motions for controller synthesis in intelligent transport system applications. In this paper, a 3-degree of freedom linear model that includes the roll motion is developed to design a robust steering controller for lane following maneuvers using ${\mu}$-synthesis. This linear perturbed system includes a set of parametric uncertainties in cornering stiffness and unmodelled dynamics in steering actuators. The state-space model with parametric uncertainties is represented in linear fractional transformation form. Design purpose can be obtained by properly choosing the frequency dependent weighting functions. The objective of this study is to keep the tracking error and steering input energy small in the presence of variations of the cornering stiffness coefficients. Furthermore, good ride quality has to be achieved against these uncertainties. Frequency-domain analyses and time-domain numerical simulations are carried out in order to evaluate these performance specifications of a given vehicle system. Finally, the simulation results indicate that the proposed robust controller achieves good performance over a wide range of uncertainty for the given maneuvers.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.35-41
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• 2009

A waypoint tracking algorithm(WTA) is designed for Unmanned Surface Vehicle(USV) in which water-jet system is installed for propulsion To control the heading of USV for waypoint tracking, the steering nozzle of water-jet need, to be controlled. Firstly, target heading is calculated by using the position information of waypoints input from the land control center. Secondly, the command for the steering nozzle of water-jet is calculated in real time by using the heading and the rate-of-turn( ROT) from magnetic compass, In this study, in order to consider the drift angle due to external disturbance such as wind and wave, the course of ground( COG) can be used instead of heading at higher speed than a certain value, To test the performance of newly-designed WTA, the tests were carried out in actual sea area near Gwang-an bridge of Busan. In this paper, the sea trial test results from WTA are analyzed and compared with those from manual control and those from commercial controller.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.194-201
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• 2000

It is called vehicle pull when a vehicle drifts in the lateral direction under the straight-ahead motion with no steering or external input. Recently vehicle pull draws attention as one of the critical evaluation items from the customers on the vehicle quality. It is generally recognized that the vehicle pull is complex phenomena due to internal and external factors. In this paper the relations between vehicle pull and ire were investigated through close survey on the road test results from the final inspection of car manufactures. Through this investigation the factors are identified which play an important role in causing vehicle pull problem.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1103-1108
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• 2007

This paper describes a robust model-based roll state estimator for application to the detection of impending vehicle rollover. The roll state estimator is based on a 2-D bicycle model and a roll model to estimate the maneuver-induced vehicle roll motion. The measurement signals are lateral acceleration, yaw rate, steering angle, and vehicle speed. Vehicle mass is adapted to obtain robust performance of the estimator. Computer simulation is conducted to evaluate the proposed roll state estimator by using a validated vehicle simulator. It is shown that the roll state estimator shows robust performance without exact vehicle mass information.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.183-192
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• 2003

Obstacle detection and avoidance are considered as one of the key technologies on an unmanned vehicle system. In this paper, we propose a method of obstacle detection and avoidance and it is composed of vehicle control, modeling, and sensor experiments. Obstacle detection and avoidance consist of two parts: one is longitudinal control system for acceleration and deceleration and the other is lateral control system for steering control. Each system is used for unmanned vehicle control, which notes its location, recognizes obstacles surrounding it, and makes a decision how fast to proceed according to circumstances. During the operation, the control system of the vehicle can detect obstacles and perform obstacle avoidance on the road, which involves vehicle velocity. In this paper, we propose a method for vehicle control, modeling, and obstacle avoidance, which are evaluated through road tests.

• Journal of Biosystems Engineering
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• v.33 no.6
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• pp.423-429
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• 2008

This study was performed to investigate the effects of inertial navigation system (INS) / global positioning system (GPS) sensor fusion for agricultural vehicle navigation. An extended Kalman filter algorithm was adopted for INS/GPS sensor fusion in an integrated mode, and the vehicle dynamic model was used instead of the navigation state error model. The INS/GPS system was consisted of a low-cost gyroscope, an odometer and a GPS receiver, and its performance was tested through computer simulations. When measurement noises of GPS receiver were 10, 1.0, 0.5, and 0.2 m ($1{\sigma}$), RMS position and heading errors of INS/GPS system at 5 m/s straight path were remarkably reduced with 10%, 35%, 40%, and 60% of those obtained from the GPS receiver, respectively. The decrease of position and heading errors by using INS/GPS rather than stand-alone GPS can provide more stable steering of agricultural equipments. Therefore, the low-cost INS/GPS system using the extended Kalman filter algorithm may enable the self-autonomous navigation to meet required performance like stable steering or more less position errors even in slow-speed operation.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1051-1059
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• 2008

In the development process of an ECU (Electrical Control Unit), numerous tests are necessary to evaluate the performance and control algorithm. The vehicle based test is expensive and requires long time. Also, it is difficult to guarantee the safety of the test driver. To overcome the various problems faced in the development process, the ECU test has been done using HIL (Hardware In the Loop). The HIL environment has the actual hardware including an ECU and a virtual vehicle model. In this paper, the test platform environment is devloped for the AWS ECU black box test. The test platform is built on HIL (Hardware In the Loop) architecture. Using the developed test platform, the control algorithm of the AWS ECU can be evaluated under the virtual driving condition of the bi-modal tram. Driving conditions, such as a front steering angle and vehicle velocity, are defined through the PC (Personal Computer) input. Input signals are transformed to electrical signals in the PC. These signals become the input conditions of the AWS ECU. The AWS ECU is stimulated by arbitory input conditons, and responses of the system are observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.575-580
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• 2016

This paper sought to find a way to improve the fuel consumption rate of a vehicle for the Shell Eco-marathon Asia 2014, with a special focus on the correlation between vehicle dynamics, aerodynamics and chassis weight reduction. In 'KUTY-Eco 1' designed for SEM Asia 2014, a chassis made with an aluminum alloy tube, semi-monocoque structure and a pivot steering system were adopted to reduce weight and to secure better performance. The goals were achieved using computer-aided engineering(CAE) and parameter study. Finally, 'KUTY-Eco 1' was created, the lightest car in the competition's prototype petrol(gasoline) type category. 'KUTY-Eco 1' secured the official record of 142.7 km/liter during the competition.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.574-581
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• 2019

This paper investigates the effects of thrust misalignments and offsets of the lateral center of gravity of a space launch vehicle on its guidance performance. Sensitivity analysis and Monte Carlo simulations are applied to analyze their effects by computing changes in orbit injection errors when including the error sources. To compensate their effects, the attitude controller including an integrator additionally and the Steering Misalignment Correction (SMC) routine of the Saturn V are considered, and then Monte Carlo simulations are performed to evaluate their performances.