• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.4
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• pp.281-285
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• 2013

In this paper, a design scheme of a cruise control system for an electric vehicle using piece-wised PD control is proposed. Cruise control of electric vehicles is one of the major performance elements. Drive motors having linear characteristics ideally is required in order to achieve the cruise driving. But practical motors have nonlinear characteristics and the performance of the motors can be improved by the closed-loop control to compensate it. In this paper, we improved the performance of by applying piece-wised PD control because the driving motors having nonlinear characteristics are difficult to obtain adequate performance only using closed-loop control. In order to test the proposed method, the experiments were carried out by applying the proposed method after setting up an electric vehicle equiped with a driving motors having large nonlinear characteristics. The experiment results of the proposed piece-wised PD control shows better performance than that of closed-loop control.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.856-864
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• 2008

This paper describes a vehicle low speed driving assistant (VLDA) system that is composed of laser scanner. This vehicle is designed for following lead vehicle (LV) without driver's operation. The system is made up several component systems that are based on unmanned ground vehicle (UGV). Each component system is applied to use advanced safety vehicle developed to complete UGV system. VLDA system was divided into vehicle control system and obstacle detecting system. The obstacle detecting system calculate distance and angle of LV and transmit these data to vehicle control system using front, left and right laser scanners. Vehicle control system makes vehicle control values such as steering angle, acceleration and brake position and control vehicle's movement with steering, acceleration and brake actuators. In this research, we designed VLDA system like as low speed cruise control system and test it on real road environments.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.68-75
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• 1998

The Intelligent Cruise Control system, ICC, is a driver assisting system for controlling relative speed and distance between two vehicles in the same lane. The ICC may be considered as an extension of a traditional cruise control, not only keeping a fixed speed of the vehicle, but correcting the speed also to that of a slower one ahead. This paper presents a real-time self-tuning fuzzy control algorithm to develop ICC. The self-tuning fuzzy control law is adopted to reduce the effects of nonlinearities of the vehicle and various road environments. In the self-tuning algorithm an interior penalty method is applied to preserve the inherent order of membership functions and is modified as an on-line algorithm for real time application. Via simulations, the performance of the suggested control algorithm is compared with a PID and a fuzzy control without self-tuning. The suggested control algorithm is implemented on PRV III and the results of the test driving on a local road are given.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.163-172
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• 2004

Nowadays, to analyze the dynamic characteristics of the automotive driving system, the computer simulation linked up with VR(Virtual Reality) technology is treated as the useful method with the improvement of computing ability. In this paper, the VR simulation system has been developed to investigate the driving characteristics of the ASV(Advanced Safety Vehicle) equipped with an ACC(Adaptive Cruise Control) system. For the purpose, VR environment which generates 3D graphic and sound information of the vehicle, the road, the facilities, and the terrain has been organized for the driving reality. Mathematical models of vehicle dynamic analysis including the ACC model have been constructed for computer simulation. The ACC modulates the throttle and brake functions to regulate the vehicle speed so that vehicles could keep proper spacing. Also, the real-time simulation algorithm synchronizes vehicle dynamic simulation with the graphic rendering. With the developed VR simulation system, simple scenarios are applied to analyze the dynamic characteristics. It is shown that the VR simulation system could be useful to evaluate the adaptive cruise controlled vehicle on various driving conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.1 no.1
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• pp.70-78
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• 2002

Advanced safety vehicle (ASV) equipped with intelligent drivers advisory functions for controlling vehicle to follow the lead vehicle and/or warning drivers on forward traffic impediments according to the roadway and traffic circumstances has been recently developed and on the market internationally. Standardization processes for ASV system functions have been issued in IS0/TC204 Working Group 14 (Vehicle/Roadway Warning and Control System) since 1995. Research projects developing test and evaluation technologies for ASV in establishing safety standards and/or conformity related to the national roadway and traffic circumstances are under study internationally. In Korea, an integrated test and evaluation Program was developed for the assessment of adaptive cruise control (ACC) system under the ITS research and development projects funded by the Ministry of Construction and Transportation (MOCT). This paper demonstrates the integrated test and evaluation Programs for ACC system based on the draft international standard with related to the domestic roadway and traffic conditions. Field tests fulfilled under the scenarios based on the integrated test & evaluation programs for ACC system are discussed along with a review of earlier research work regarding international standards and the safety regulations.

• Journal of Power System Engineering
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• v.15 no.2
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• pp.19-24
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• 2011

In this study, a control method of MR(magneto-rheological) damper for a cruise bus is investigated. A virtual dynamic damper and a sky-hook algorithm are employed to control the damping characteristics of MR damper. Coefficients for a virtual dynamic damper are determined through the parameter identification. A quarter car model of a cruise bus is established by using ADAMS/Car program for the computer simulation. Sine wave excitation and random excitation are used to compare the controlled MR damper with the passive damper. From the simulation results, the performance of MR damper with a virtual dynamic damper is better than that of the passive damper.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.202-213
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• 1999

Adaptive Cruise Control (ACC) is one of key features on intelligent Transportation System(ITS). In ACC, the steering is done by a driver, but the engine throttle valve and the brake are controlled electronically. The relative velocity and distance from the preceeding vehicle are measured by radars or image processing units and relevant vehicular spacing is maintained in ACC control systems. In this study, vehicle longitudinal dynamics are modeled to simulate vehicle longitudinal maneuver and to design longtitudinal controllers for ACC vehicles. The control algorithm is designed based on the modeled vehicle longitudinal dynamics using a non-linear sliding mode control method. To verity the performance of the control algorithm, a real time numerical simulation program is developed on a Silicon Graphics workstation using C-language . A real time graphic program is alos develpe and integrated with the numerical simulation program.

• Journal of Mechanical Science and Technology
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• v.20 no.1
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• pp.29-41
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• 2006

Nowadays, with the advancement of computers, computer simulation linked with VR (Virtual Reality) technology has become a useful method for designing the automotive driving system. In this paper, the VR simulation system was developed to investigate the driving performances of the ASV (Advanced Safety Vehicle) equipped with an ACC (Adaptive Cruise Control) system. For this purpose, VR environment which generates visual and sound information of the vehicle, road, facilities, and terrain was organized for the realistic driving situation. Mathematical models of vehicle dynamic analysis, which includes the ACC algorithm, have been constructed for computer simulation. The ACC algorithm modulates the throttle and the brake functions of vehicles to regulate their speeds so that the vehicles can keep proper spacing. Also, the real-time simulation algorithm synchronizes vehicle dynamics simulation with VR rendering. With the developed VR simulation system, several scenarios are applied to evaluate the adaptive cruise controlled vehicle for various driving situations.

• Journal of Drive and Control
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• v.14 no.3
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• pp.8-17
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• 2017

With automobiles sharply increasing in numbers worldwide, we are faced with critical social issues such as traffic accidents, traffic jams, environmental pollution, and economic inefficiency. In response, research on ITS is promoted mainly by regions with advanced automotive industry such as the U.S., Europe, and Japan. While Korea is working on moving forward in the global market through developing and turning to global standards systems related to ASV (Advanced Safety Vehicle), the country is not fully prepared for such projects. The purpose of ACC (Adaptive Cruise Control) is to control a vehicle's longitudinal speed and distance and minimize driver workload. Such a system should be valuable in preventing accidents, as it reduces driver workload in the 21st-century world of telematics created by development of the automobile culture industry. In this light, the thesis presents a method to test and evaluate ACC system and a mathematical method to assess distance. For the proposed test and evaluation, theoretical values are tested with vehicle test and a database is acquired, by using vehicles equipped with an ACC system. Theoretical evaluation criteria for developing ACC system may be used and scenario-specific evaluation methods may find useful application through testing the formula proposed by comparing the database and mathematical method.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.9-17
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• 2010

In this paper, an automatic cruise system of unmanned boat was developed for surveying water depth in reservoir using GIS (geographic information system)-GPS (global positioning system) Technologies. the automatic cruise system consisted of an automatic path generation program (APGP) and an automatic boat control program (ABCP). A grid processing method with $3{\times}3$ roving window in GIS function was used to develop the APGP. For development of the ABCP, GPS and its coordinate calculation technique were introduced. The developed system was tested to verify the applicability for a sample reservoir, Misan reservoir located on Ansan city of Kyunggi province. From the test results, this study found the APGP generated cruise path automatically according to input condition on grid size of 5 m, 10 m, and 20 m, as well as, the ABCP also tracked well the cruise paths with high position accuracy. Another verification result on surveying time for 20 ha of water area also showed that the new system could survey water depth of reservoir quickly, including very high quality of spatial resolution.