• International Journal of Automotive Technology
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• 제5권2호
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• pp.135-144
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• 2004

In this paper, the model-matching control in the longitudinal autonomous driving system is investigated by vehicle dynamics simulation, which contains nonlinear subcomponents and simplified subcomponents. The design of the robust model-matching controller is performed by the characteristics of the 2 degrees of freedom controller, which is composed of the feedforward compensator and the feedback compensator. It makes the characteristics of tractive and brake force to be equivalent to the specific transfer function, which is suggested as the reference model. Mathematical models of vehicle dynamic analysis including the model-matching control are constructed for computer simulation. Then, simple examples on open-loop simulation without any controller and closed loop simulation with the model-matching controller are applied to check the validity of the robust controller. As the practical example, the autonomous driving system in the longitudinal direction is adopted. It is proved that the model-matching control is effective and adequate to the disturbances and the perturbations, which are shown in the responses of the change of a vehicle mass and a road gradient.

• 자동차안전학회지
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• 제7권2호
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• pp.44-49
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• 2015

This paper presents an evaluation scenario of safety performance for extraordinary service permission of autonomous vehicle driving on a motorway. Based on advanced driver assistance system (ADAS) which is already mass-production, an autonomous vehicle driving on motorway is tested on the public roads and also getting close to mass-production. Before the autonomous vehicle tested, the safety of autonomous driving system should be evaluated based on a proper test scenario. Prior to develop the test scenario, this paper reviews the licensing standards for an autonomous vehicle in California and Nevada, and the international regulations of each ADAS. To develop the scenario, the driving conditions of motorway are categorized into five modes and fundamental evaluation requirements of elements of autonomous driving system are derived. An evaluation scenario, which represents the real driving conditions, has been developed to assess the safety of autonomous vehicle. This scenario has validated by computer simulation using model predictive control (MPC) based autonomous driving algorithm.

• 한국정밀공학회지
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• 제17권4호
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• pp.121-128
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• 2000

In this paper, the control algorithm fur an autonomous vehicle is studied and applied to an actual 2 wheel-driven vehicle system. In order to control a nonholonomic system, the kinematic model for an autonomous vehicle is constructed by relative velocity relationship about the virtual point at distance from the vehicle's frame. And the optimal controller that based on the kinematic model is operated on purpose to track a reference vehicle's path. The actual system is designed with named 'HYAVI' and the system controller is applied. Because all the results of simulation don't satisfy the driving conditions of HYAVI, a reformed control algorithm that satisfies an actual autonomous vehicle is applied at HYAVI. At the results of actual experiments, the path tracking works very well by the reformed control algorithm. An autonomous vehicle that applied this control algorithm can be easily used for a path generation algorithm.

• 자동차안전학회지
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• 제15권3호
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• pp.34-42
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• 2023

Simulation-based virtual testing is known to be a major requirement for verifying the safety of autonomous driving functions. However, in the simulation environment, there is a difficulty in that all driving environments related to the autonomous driving system must be realistically modeled. In particular, C-ITS (Cooperative-Intelligent Transport Systems) is essential for urban autonomous driving of Lv.4, but the approach to modeling for C-ITS service in the MILS (Model in the Loop Simulation) environment is not yet clear. Therefore, this paper aims to deal with V2X (Vehicle to Everything) modeling methods to effectively apply C-ITS-based autonomous cooperative driving services in the MILS environment. First, major C-ITS services and use cases for autonomous cooperative driving are analyzed, and a modeling method of V2X signals for C-ITS service simulation is proposed. Based on the modeled V2X messages, the validity of the proposed approach is reviewed through simulations on the C-ITS service use case.

• ETRI Journal
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• 제44권4호
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• pp.641-653
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• 2022

In the process of autonomous vehicle motion planning and to create comfort for vehicle occupants, factors that must be considered are the vehicle's safety features and the road's slipperiness and smoothness. In this paper, we build a mathematical model based on the combination of a genetic algorithm and a neural network to offer lane-change solutions of autonomous vehicles, focusing on human vehicle control skills. Traditional moving planning methods often use vehicle kinematic and dynamic constraints when creating lane-change trajectories for autonomous vehicles. When comparing this generated trajectory with a man-generated moving trajectory, however, there is in fact a significant difference. Therefore, to draw the optimal factors from the actual driver's lane-change operations, the solution in this paper builds the training data set for the moving planning process with lane change operation by humans with optimal elements. The simulation results are performed in a MATLAB simulation environment to demonstrate that the proposed solution operates effectively with optimal points such as operator maneuvers and improved comfort for passengers as well as creating a smooth and slippery lane-change trajectory.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1349-1354
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• 1990

This paper deals with the control of autonomous vehicle in the production systems. Presently, there is a significant interest in autonomous vehicles which are capable of intelligent motion (and action) without requiring a guide track to follow. This paper describes a PI-F adaptive control algorithm, which is used to drive an experimental autonomous vehicle along a given trajectory. The simulation results characterizing the accuracy og the algorithm are presented.

• 자동차안전학회지
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• 제15권4호
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• pp.23-31
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• 2023

In recent years, the technology for autonomous driving has been advancing rapidly, ADAS (Advanced Driver Assistance System) functions, which improve driver convenience and safety performance, are mostly equipped in recently released vehicles and range from level 0 to level 2 in autonomous driving technology. Among the various functions of ADAS, AEBS (Autonomous Emergency Braking System), which analyzes traffic accidents, is the most closely related to the vehicle's braking. This study developed a simulation technique for reproducing accidents related to AEBS based on real vehicle experimental data, and it was applied to the analysis of actual ADAS vehicle accidents to identify the causes of accidents.

• 자동차안전학회지
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• 제15권4호
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• pp.39-47
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• 2023

Research on the safety of autonomous vehicle is being conducted in various countries, including the European Union, and computer simulation techniques so called 'Virtual Tool Chain' are mainly used. As part of the crash safety study of autonomous vehicle, 25 car to car collision scenarios were provided as a result of a real accident-based accident reproduction analysis study conducted by a domestic research institution, and a vehicle crash analysis was performed using the FE car to car model of the Honda Accord. In order to analyze the results of the car to car simulation and to construct a database, major crash parameters were selected as impact speed, angle, location, and overlap, and a method of defining them in an indexed form was presented. In order to compare the crash severity of each scenario, a value obtained by integrating the resultant acceleration measured by the ACU of the vehicle was applied. The equivalent collision test mode was derived by comparing the crash severity of the regulation test mode, 30 deg rigid barrier mode, in the same way.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.57-62
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• 2003

This paper describes the design and simulation of a multivariable optimal control system for the combined speed, heading and depth control of a Semi-Autonomous Underwater Vehicle (SAUV) developed in Korea Ocean Research and Development Institute (KRODI). The SAUV is a test-bed for the evaluation of the navigation and manipulator technologies developed for a mine disposal vehicle (MDV) in military use and for a light working underwater vehicle in scientific use. The vehicle was designed to control its cruising speed, heading and depth with 4 horizontal thrusters installed at the rear of the hull. Therefore, the decoupled control methods are limited to apply to the SAUV because the thrust forces are highly coupled with the surging, yawing, and pitching motion of the vehicle. The multivariable Linear Quadratic (LQ) control method is chosen to control steering and diving in variable speed motion automatically. A series of simulation is carried out with fully nonlinear six degree of freedom dynamic model to validate the controller.

• 동력기계공학회지
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• 제20권1호
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• pp.24-29
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• 2016

Remotely operated vehicles or autonomous underwater vehicles have been used for exploiting seabed natural resources. In this study, the autonomous underwater vehicle of hovering type(HAUV) is developed to observe underwater objects in close distance. A dynamic model with six degrees of freedom is established, capturing the motion characteristics of the HAUV. The equations of motion are generated for the dynamic control simulation of the HAUV. The added mass, drag and lift forces are included in the computer model. Computational fluid dynamics simulation is carried out using this computer model. The drag coefficients are produced from the CFD.