Operation Control Method Research Articles

Conditional Bus Priority at Signalized Intersections: Better Service with Less Traffic Disruption

Conditional priority for buses at signalized intersections means that late buses are given priority and early buses are not. This scheme is a method of operational control that improves service quality by keeping buses on schedule. A conditional bus priority implementation in Eindhoven, the Netherlands, is described. Results show the strong improvement in schedule adherence compared with a no-priority situation. Traffic impacts at an intersection were studied for three scenarios—no priority, absolute priority, and conditional priority. Compared with no priority, absolute priority increased delays significantly while conditional priority had almost no impact.

98/02266 Combustion apparatus and its operation control method

98/02266 Combustion apparatus and its operation control method

太陽熱利用給湯システムにおける貯湯槽内の温度性状と補助熱源機の稼働制御に関する研究

The authors manufactured a hot water supply system with solar panels. Water in a storage tank was heated by the fluid path through solar panels and a heat-pump as a back-up heater. This system was operated in three modes through a year, and following results were obtained. (1) In the case that using pattern of the hot water was based on an energy conservation handbook, the maximum hot water demand occurred in supplying to a bathtub. Then for the maximum demand it was necessary to prepare 300l hot water which was more than 50℃, in the storage tank. In other time, it was necessary to prepare 100l hot water which was more than 50℃. (2) The efficiency of solar energy to heat water in the storage tank was obtained. The prediction control of heat-pump operation was possible by using neural network. Furthermore, the authors showed an operation control method to supply for the maximum demand of hot water and to conserve energy.

Development of a hybrid margin angle controller for HVDC continuous operation

The objective of this paper is to present a new hybrid margin angle control method for HVDC continuous operation under AC system fault conditions. For stable continuous operation of HVDC systems, the margin angle controller must be designed to maintain the necessary margin angle to avoid commutation failures. The proposed method uses the open loop margin angle controller (MAC) as the basic controller, and adds output from the closed loop MAC to correct the control angle. A fast voltage detection algorithm is used for open loop control, and margin angle reference correction using harmonics detection for closed loop control are also developed. The combination of open and closed loop control provides quick responses when faults occur with stable and speedy recovery after fault clearance. The effectiveness of the developed controller is confirmed through EMTP digital simulations and also with the experiments using an analogue simulator.

95/05083 System for coal gasification combined with power generation and its operation control method

95/05083 System for coal gasification combined with power generation and its operation control method

Discussion and Closure: Control Method for On-Demand Operation of Open-Channel Flow

Discussion and Closure: Control Method for On-Demand Operation of Open-Channel Flow

Inverse method for operational control of canal systems

A non-linear explicit inverse solution method for the operational control of remotely controlled canal systems is presented. The model accounts for canal seepage, turnout flows (point sink), control structures with steeply varying and/or discontinuous discharge characteristics. The governing unsteady flow equations are solved backward both in space and time. For each space interval, the use of finite difference approximations for the operational problem results in a system of two non-linear equations in two unknowns. These equations are solved using Newton's method. The method is extended to canal networks. The canal junctions are classified into three types. The controllability of flow for each type of canal junction and for the network as a whole are discussed. The model, though explicit, is found to be unconditionally stable. The model results are verified with the unsteady flow simulation model based on non- linear Preissmen's scheme. The applicability of the model to a canal system is demonstrated.

Closure to “Control Method for On-Demand Operation of Open-Channel Flow” by José Rodellar, Manuel Gómez, and Luis Bonet

Closure to “Control Method for On-Demand Operation of Open-Channel Flow” by José Rodellar, Manuel Gómez, and Luis Bonet

自由浮遊する宇宙用テレロボット・モデルによる対象物の捕捉制御実験

This paper presents an experimental study on a control problem of a space manipulator installed on a free-flying telerobot. The authors' main goal is to develop a control method for dexterous operation of telerobot, with considering the dynamical interaction between the manipulator arm and the base satellite in space micro-gravity environment. In order to control space free-flying manipulators, the generalized Jacobian matrix is introduced. By substituting the conventional Jacobian for this matrix, conventional control methods for ground-fixed manipulators is directly applicable for space manipulators. In order to simulate the free-flying behavior of mechanical links in micro-gravity environment, a laboratory model of space telerobot supported on air bearings is developed. An on-line resolved motion-rate control scheme with vision feedback is proposed for experimenting target capture operation, by means of the generalized Jacobian matrix. The telerobot model can properly chase and capture both a standing target and a moving target in spite of complex satellite/manipulator dynamical interaction. The experimental results confirm the validity of the generalized Jacobian concept and proposed control method.

New Approach to a High-Power GTO PWM Inverter for AC Motor Drives

A control method for GTO PWM inverter parallel-set operation and a new protection system for prevention of short-circuit faults caused by turn-off failure, both to realize a high-power drive system are described. Timing control of GTO gate pulse command provided by a feedback loop, and a reactor at the output of the inverter can minimize the cross current flowing between inverters and can balance the output current of each inverter in inverter parallel-set operation. This method eliminates the necessity of selecting GTO's of equal characteristics, and can apply to parallel-set operation of three or more inverters. The new protection system judges the on and off states of the GTO from the GTO gate-cathode voltage and detects turn-off failure of the GTO. This method positively stops the inverter system safely and reliably upon turn-off failure of the GTO. Experiments are carried out on a 30-kVA inverter and two sets of 450-kVA GTO inverters.

4647421 Operation control method for nuclear reactor : Masahis Ohashi, Hiroyuk Masuda, Hitachi, Japan assigned to Hitachi Ltd

4647421 Operation control method for nuclear reactor : Masahis Ohashi, Hiroyuk Masuda, Hitachi, Japan assigned to Hitachi Ltd

Automatic threshold-level control (ATC) for optimum decision operation in optical repeaters

An automatic threshold-level control (ATC) method for optimum decision operation in an optical repeater is studied using in-service error monitoring in the line code with the bit-inversion rule. Results of an experiment with a 110 Mbit/s optical repeater and a 10B1C line coder clarify that the ATC method is effective for maintaining the optimum decision threshold level.

An Efficient Control Method for Operation of Multiple Pumps

In water and wastewater treatment, we have many requirements with regard to conservation for energy and other resources. In this paper we propose an efficient operation method for a pumping station with multiple pumps, which is optimal in the sense of lowering electric power consumed by pumps and eliminating undesirable pump switchings. We propose an algorithm suitable for practical use, and show its usefulness by numerical examples. And we show that the optimal switching points and speeds for pumps under the proposed method can be determined from given pump characteristics.