• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.855-860
• /
• 2007

This paper describes a human driver model developed based on finite preview optimal control method. The human driver steering model is constructed to minimize a performance index which is a quadratic form of lateral position error, yaw angle error and steering input. Simulation studies are conducted using a vehicle simulation software, Carsim. The Carsim vehicle model is validated using vehicle test data. In order to validate the human driving steering model, the human driver steering model is compared to the driving data on a virtual test track(VTT) and the actual vehicle test data. It is shown that human driver steering behaviors can be well represented by the human driver steering model presented in this paper

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.115-119
• /
• 2007

In this paper, practical problems will be covered in applying preview control to real tracked vehicle systems. Previous researches about the preview control assume that the vehicle speed is constant and the actuators have full frequency bandwidth. However, in order to apply it to real systems, those should be taken into account. Therefore this paper show the algorithm to apply the preview control to speed changing vehicles and performance variation according to a restricted frequency bandwidth.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.209-212
• /
• 2005

The look-ahead preview control with the use of limited bandwidth active suspensions is presented. Both a linearized racked vehicle model and a complex nonlinear model based on a commercial multibody dynamic program are used to verify the performance of preview control. The performance of the preview control system is evaluated on the ride quality which is estimated from the acceleration of the driver position. Due to the practical advantages associated with the use of limited bandwidth active control in comparison with full bandwidth systems, the results are considered important to the future development of active tracked vehicle suspensions.

• Journal of Drive and Control
• /
• v.14 no.2
• /
• pp.9-15
• /
• 2017

The steering systems of all-terrain cranes have been developed with various control strategies for the stability and drivability. To optimally control the input steering angle, an accurate mathematical model that represents the actual crane dynamics is required. The derivation of an accurate mathematical model to optimally control the steering angle, however, is difficult since the steering-control strategy generally varies with the magnitude of the crane's longitudinal velocity, and the postures of the crane's working parts vary while it is being driven. To address this problem, this paper proposes an automatic steering-control algorithm that is based on the MPC (model predictive control) with a disturbance observer for all-terrain cranes. The designed disturbance observer of this study was used to estimate the error between the base steering model and the actual crane. A model predictive controller was used for the computation of the optimal steering angle, along with the use of the base steering model with an estimated uncertainty. Performance evaluations of the designed control algorithms were conducted based on a curved-path scenario in the Matlab/Simulink environment. The performance-evaluation results show a sound reference-path-tracking performance despite the large uncertainties.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.1068-1071
• /
• 1993

An algorithm of fuzzy predictive sliding control is proposed to design a jet engine control system. Sliding control using predictive scheme is adopted to compensate the time delay of fuel injector. Fuzzy rule-base is also introduced to adjust the command input for suppressing the surge. The potential of the proposed algorithm is shown through simulations utilizing a typical engine-only model.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.892-895
• /
• 1996

An unknown input observer is proposed that can be used in wheelbase preview control of commercial vehicles. The preview and state information, required to calculate actuator force, are reconstructed from the measurement variables such as heave and pitch acceleration. Gain matrix of observer is optimally selected so that influence of system and measurement noises on the estimation error can be minimized. Estimated preview information requires low pass filtering to eliminate high frequency components resulting from differentiation of noisy output signals. Effectiveness of the proposed method is demonstrated by numerical simulation of half car model.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.160-166
• /
• 2018

This paper proposes an advanced suspension system and reports its performance in the framework of the preview control algorithm based on the RPS (road profile sensing) system and MSD system with the multi-stage damping characteristics. Typical disturbance inputs that cause excessive vibration and steering instability of an automobile are irregular obstacles that protrude or sink into the road surface to be driven. The control performance can be improved if information on the existence and shape function of its obstacle is known. Based on the results of the previous study, advanced research that uses the actuating system has been processed to be commercialized practically. For this purpose, a switching algorithm between the control logic and the multi-stage damping system was developed and its connectivity is presented. To verify the applicability of an actual vehicle, the proposed control system was implemented in full vehicle models and simulations were performed. The proposed system using the 3-DS actuator system, which is applied for structural simplicity, can improve the ride comfort and steering stability. In addition, the results indicate the feasibility of the intelligently controlled suspension system.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.6
• /
• pp.431-437
• /
• 2017

In this study, based on the RPS algorithm, the application results to an electrically controlled suspension system using previewed road information are presented. Reducing the excessive vibration induced by a disturbance transmitted to the system and secure its stability is a major issue. In particular, in the automotive industry, the demand is constantly being raised. A typical external disturbance causing vibration and instability of a vehicle is an irregular roadway surface that contacts a running vehicle tire. Therefore, obtaining such profile information is an important process. The RPS algorithm using a multi sensor system was constructed and implemented in a real car. Through experimental work using the RPS system included non-contact type optical sensors, it could robustly reconstruct the road input profiles from the intermixed data onto the vehicle's dynamic motion while traveling at an uneven roadway surface. A controller with a preview control was designed in the framework of a semi-active suspension system based on the 7 degrees of freedom full vehicle model. The control performance of the system was evaluated through simulations and the results were compared with the passive vehicle condition. These results highlight the feasibility of the presented control frame.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.4
• /
• pp.906-912
• /
• 2014

The study of fish robot is a main subject that are related with the propulsive force comparison using a varying amplitude and frequency for body and tail motion trajectory, and the quick turn using a proper trajectory function. In this study, when a fish robot thrusts forward, feedback control is difficult to apply for a fish robot, because body and tail joints as a sine wave are rolled. Therefore, we detect the virtual position based on the path of the fish robot, define the angle errors using the detected position and the look-ahead point on the given path, and design a controller to track given path. We have found that the proposed method is useful through the computer simulations.

• Journal of the Korean Society of Safety
• /
• v.32 no.1
• /
• pp.1-8
• /
• 2017

In industry AGV's(automated guided vehicles) that can detect and follow guidelines drawn on the factory floor using magnetic or optical sensors are widely used. However, such AGV's without preview capability cannot effectively avoid collision with obstacles that may occasionally pass through the guideline. Furthermore, without preview information, they consume much energy at the right angle corners as they have to make sudden directional change. Also, the risk of dropping payloads increases in such situations. In this study, infrared preview sensors were adopted to a mobile robot for detecting not only the current position but also the forward position of the guideline and the preview control technique was applied to optimally control the mobile robot's motion using the information from the infrared preview sensors. Then the effectiveness of this approach was investigated through a series of experiments. The experimental result shows that the proposed approach is effective for safety enhancement as well as for better efficiency.