• Journal of Navigation and Port Research
• /
• v.33 no.1
• /
• pp.1-7
• /
• 2009

Navigation speed control is an important factor to improve the traffic safety, it is only researched about maximum speed control until now. Recently, there are lots of the low speed vessels including towing boats, carry heavy shipbuilding blocks in the Korean waters, so the danger degree of navigating vessels was increasing more and more. This paper analysed the effectiveness of minimum speed control with the operation burden's decrease, and it proposed the proper the minimum navigation speed of each traffic volume. Main results of this research are as follows. (1) in the case of 5 ships/hour, minimum speed control is effective if the lowest speed is fixed more than 5kts. (2) in the case of more than 10 ships/hour, speed control is some effective if the lowest speed is established 7kts. (3) But, when there are many ships in the waters, minimum speed control is not effective because distances between ships become near and ships navigate for a long time by a lot of ship having a few difference of relative speed.

• Proceedings of the KIEE Conference
• /
• 2008.04a
• /
• pp.213-214
• /
• 2008

This paper considers design of a robust controller that alleviates disturbance effects and compensates performance degradation of plants with time-delay. Disturbance observer(DOB) approach as a tool of robust control has been widely employed in industry. However, since the time-delay makes the plant non-minimum phase, classical DOB cannot be applied directly to the time-delay system. By using a new DOB structure for non-minimum phase systems together with the Smith Predictor, we propose a new control algorithm for reducing the effects of disturbance and time-delay of the system.

• 전기의세계
• /
• v.21 no.3
• /
• pp.31-40
• /
• 1972

This study intends to investigate the optimal switching modes of a double-capacitive thermal system under different constraints on the state and the control variable, by the application of the Pontryagin's Minimum Principle. Throughout the development, the control effort is assumed to have two modes of state: M or zero and the terminal times being fixed. In the first part of this study, the Principle is discussed under various conditions for this particular problem, with different criterion functions and in the same time imposing a certain constraints; i) on the terminal states, ii) on functions of the terminal states. Depending upon the upper bound value of the control vector, possible driving modes of the states are studied from which particular optimal driving modes are extracted so as to meet the specified constraints and boundary conditions imposed in the problem. Numerical solutions are evaluated for an over0damped, double-capacitive thermal plant and the optimal solutions: the switching mode, the optimal switching time, and the control effort are compared with the analytical results, in the second part of this work, to confirm the development.

• International Journal of Computer Science & Network Security
• /
• v.21 no.1
• /
• pp.64-69
• /
• 2021

In this paper, we have proposed a new internal model control structure (IMC). It is aimed at unstable overactuated multivariable systems whose transfer matrices are singular and unstable. The model inversion problem is essential to understand this structure. Indeed, the precision between the output of the process and the setpoint is linked to the quality of the inversion. This property is preserved in the presence of an additive disturbance at the output. This inversion approach proposed in this article can be applied to multivariable systems with no minimum phase or minimum phase shift with or without delays in their transfer matrices. It is proven by an example of simulation through which we have shown its good performance as a guarantee of stability, precision as well as rapidity of system responses despite the presence of external disturbances and we have tested this control structure in the frequency domain hence the robustness of the IMC.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.11
• /
• pp.503-510
• /
• 1986

A new algorithm based on the concept of prediction error minimization is suggested to estimate the time varying delay in discrete processes. In spite of the existence of the stochastic noise, this algorithm can estimate time varying delay accurately. Computation time of this algorithm is far less than that of the previous extended parameter methods. With the use of this algorithm, generalized minimum variance control shows good control behavior in simulations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.2
• /
• pp.211-217
• /
• 2014

This paper addresses an algorithm of path planning for autonomous driving of a ground vehicle in waypoint navigation. The proposed algorithm is flexible in utilization under a large GPS positioning error and generates collision-free multiple paths while pursuing minimum traveling time. An optimal path reduces inefficient steering by minimizing lateral changes in generated waypoints along a path. Simulation results compare the proposed algorithm with the A* algorithm by manipulation of the steering wheel and traveling time, and show that the proposed algorithm realizes real-time obstacle avoidance by quick processing of path generation, and minimum time traveling by producing paths with small lateral changes while overcoming the very irregular positioning error from the GPS.

• Journal of Power Electronics
• /
• v.16 no.2
• /
• pp.584-597
• /
• 2016

This paper focuses on an improvement in the transient performance of Boost converters when the load changes abruptly. This is achieved on the basis of the nature trajectory in Boost converters. Three key aspects of the transient performance are analyzed including the storage energy change law in the inductors and capacitors of converters during the transient process, the ideal minimum voltage deviation in the transient process, and the minimum voltage deviation control trajectory. The changing relationship curve between the voltage deviation and the recovery time is depicted through analysis and simulations when the load suddenly increases. In addition, the relationship curve between the current fluctuation and the recovery time is obtained when the load suddenly decreases. Considering the aspects of an increasing and decreasing load, this paper proposes the transient performance synthetic optimized trajectory and control laws. Through simulation and experimental results, the transient performances are compared with the other typical three control methods, and the ability of proposed synthetic trajectory and control law to achieve optimal transient performance is verified.

• 제어로봇시스템학회:학술대회논문집
• /
• 1988.10a
• /
• pp.86-91
• /
• 1988

The analytical studies and applicability of the implementation of the controller for the simple flexible arm studies and discussed in this thesis with the goal of developing flexible manipulator arm control. Minimum-time position control and quadractic-optimal control are investigated in this thesis. Its validity has been established using numerical simulations.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.676-680
• /
• 1994

Three synchronic variables (Deviation Time, Fairness Time, Synchronic Time) are defined for Timed Place Petri Nets (TPPN). These parameters show the dependency between the firing of transition subsets in the time domain by different values. The approaches in this paper can be used to find synchronic relations in Stochastic Petri Nets. This paper presents how to decide the minimum resources required to a Flexible Manufacturing Cell using Synchronic Time concept.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.430-433
• /
• 1997

In this paper, an intervalwise receding horizon control (IRHC) is proposed which stabilizes linear continuous and discrete time-varying systems each other by means of a feedback control stemming from a receding horizon concept and a minimum quadratic cost. The results parallel those obtained for continuous [4],[9] and discrete time varying system [5],[15] each other.