• Journal of Korean Port Research
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• v.13 no.2
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• pp.381-388
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• 1999

To improve the productivity in the harbor, successful development of an UCT(Unmanned Container Transporter) is needed. Well-designed steering and velocity control systems are the key factor for the development of the UCT. In this paper, a research concerning the achievement of the steering control is introduced. To get an information on the guide line that the UCT should track, the vision system is applied. By using neural network, proper steering angle is gotten fast with less influence of the image disturbance. A simulation based on the UCT kinematics is performed with the measured steering angle, and it shows satisfactory results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.363-369
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• 1999

In these days, there are a lot of studies in the port automation, for example, unmanned container trasporter, unmanned gantry crain, and automatic terminal operation systems and so on. In terms of loading and unloading equipments. we can consider container transporter. This paper describes the automatic control for the UCT(unmanned container transporter), especially steering control systems. UCT is now operated on ECT port in Netherland and tested on PSA ports in Singapore. So we present a design on the controller using neural network PID(NNPID) controller to control the steering system and we use the neural network self-tuner to tune the PID parameters. The computer simulations show that our proposed controller has better performances than those of the other.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.178-186
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• 2002

In this study, the steering control system for UCT (unmanned container transporter) was developed using MR (Magnetoresistive) sensors. The MR and magnet sensors are used for the lane detecting system. The robust control theory is used for the design of the steering controller to reduce the uncertainties of the road. The performance of the robust steering controller is compared in simulations and tests using the existing PD controller of the UCT.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.309-314
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• 1999

The major movement block of the containers is range between apron and designation points on yard in container terminal. The yard tractor operated by human takes charge of it's movement in conventional container terminal. In unmanned container terminal, UCT(unmanned container transporter) has charge of the yard tractor's role and the navigation path is ordered from upper level control system. The unmanned container terminal facilities must have docking system that guided landing line to have high speed travelling and precision positioning in unmanned container terminal. The general method for docking uses the vision system with CCD camera, infra red, and laser. This paper describes the investigation for the developed docking method in view point of merit and demerit and introduces 속 result of developing the docking system with LSB(laser slit beam).

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.972-975
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• 1999

Until now, all of the port goods are transported by container transporter driven manually but recently there are a lot of researches about unmanned vehicle driven automatically. In this paper, we present a design of the TDOF PID controller using a hybrid schematic algorithm to control steering system. We used the ES and SA algorithms to construct hybrid tuning algorithm. Then the computer simulation shows that our proposed controller has better Performances than the other one.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.315-320
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• 1999

Obstacle Detection System(ODS) is a essential system for automated vehicle, such as AGV(Automatic Guided Vehicle), mobile robot. Automated vehicle must have a capability to detect and to avoid obstacles to guarantee a safe driving condition. To implement obstacle detection system, virtual bumper concept adapted. Like real bumper in a car, such as in the truck, it protects vehicle from collision using laser distance sensor. When an obstacle(such as other vehicle, building, etc) intrudes this virtual bumper area, a virtual force is calculated and produces necessary strategy to be able to avoid collision. In this paper, simplified virtual bumper concept is presented, and various problems when happens to implement are discussed.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.227-232
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• 2004

Vehicle dynamics control systems are complex and non-linear, so they have difficulties in developing a controller for the anti-lock braking systems and the auto-traction systems. Currently the fuzzy-logic technique to estimate the absolute vehicle speed supplies good results in normal conditions. But the estimation error in severe braking is discontented In this paper, we estimate the absolute vehicle speed of UCT(Unmanned Container Transporter) by using the wheel speed data from standard anti-lock braking system wheel speed sensors. Radial symmetric basis function of the neural network model is proposed to implement and estimate the absolute vehicle speed, and principal component analysis on input data is used 10 algorithms are verified experimentally to estimate the absolute vehicle speed and one of them is perfectly shown to estimate the vehicle speed within 4％ error during a braking maneuver.

• Journal of Korean Port Research
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• v.15 no.1
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• pp.37-46
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• 2001

Fuzzy logic control(FLC) is composed of three parts : fuzzy rule-bases, membership functions, and scaling factors. Well-defined fuzzy rule-base should contain proper physical intuition on the plant, so are needed lots of experiences of the skillful expert. When membership functions are considered, some parameters on the memberships function such as function shape, support, allocation density should be selected well. The rule of scaling factors is 'scaling'(amplifying or reducing) for both input and output signals of the FLC to fit in the membership function support and to operate the plant intentionally. To get a better performance of the FLC, it is necessary to adjust the parameters of the FLC. In general, the adaptation of the scaling factors is the most effective adjustment scheme, compared with that of the fuzzy rule-base or membership function parameters. This study proposes the adaptation scheme of the scaling factors. When the adaptation is performed on-line, the stability of the adaptive FLC should be guaranteed. The stable FLC system can be designed with stability analysis in the sense of Lyapunov stability. To adapt the scaling factors for the error signals, the concept of the conventional MRAC would be introduced into slightly modified form. A tracking accuracy of the control system would be enhanced by the modified shape and support of the membership function. The simulation is achieved on the pilot plant with the hydraulic steering control of a UCT(Unmanned Container Transporter) of which modeling dynamics have lots of severe uncertainties and modeling errors.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.326-333
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• 2001

This paper focuses on a method to connect mobile devices such as mobile robot. Automated Guided Vehicle (AGV) and Unmanned Container Transporter(UCT) to a fieldbus. In this paper, the IEEE 802.11 wireless LAN is used to extend a Profibus network for the mobile devices. In order to integrate these two networks, a gateway is developed using two threads and an internal buffer. Furthermore, a polling algorithm is applied at the gateway in order to satisfy real-time requirements on data communication, Finally, the performance measures such as data latency and throughput are experimentally evaluated on a wirelessly-extended Profibus network. The results shows the feasibility of the wireless extension of Profilbus for various mobile device.