V. Tipsuwanporn

DC Motor Speed Control using Fuzzy Logic based on LabVIEW

This paper presents implement in speed control of a separately excited DC motor using fuzzy logic control (FLC) based on LabVIEW (Laboratory Virtual Instrument Engineering Workbench) program. LabVIEW, is a graphical programming environment suited for high-level or system-level design. Therefore, the principle that are data flow model, different from text-base programming and a sequential model. The user-friendly interface and toolbox design are shown the high level of suitableness and stability of LabVIEW and fuzzy logic on speed control of DC motor. The fuzzy logic controller designed to applies the required control voltage that sent to DC motor based on fuzzy rule base of motor speed error (e) and change of speed error (ce). The results show the control as a FLC that do the comparison with PI and PID controller

PID Controller Design using Characteristic Ratio Assignment Method for Coupled-Tank Process

This paper presents the PID controller design for coupled-tank process using characteristic ratio assignment (CRA). The coupled-tank process is a challenge plant for testing the performance of PID controller because it is a high uncertainty nonlinear model. For this paper, the characteristic ratio assignment (CRA) which is satisfied specification of performance of control system. Furthermore, it is very convenient as a fast adjustment damping ratio as well as a high speed response. Finally, the simulation results can be illustrated the validity of our approach by MATLAB

Modeling of the modified Quadruple-Tank Process

This paper presents Modeling of the Modified Quadruple-Tank Process. The new general form of plant model is developed for illustrating the highly flexible plant structure which can be adjusted to many styles that are used for the propose of giving control system engineers experience with multivariable control system design. In this paper described clearly about structure and physical properties of Modified Quadruple-Tank Process, Mathematical plant modeling, Analysis of plant transfer matrix characteristic, Transformation of general form of plant model to several different styles of water level plant. The value of General form modeling concept for Modified Quadruple-Tank process is ability in transform its transfer matrix to several different styles just only assign the value of inlet and outlet valve ratio. By the several model of transformed Modified Quadruple-Tank, it can be used to teach students in the skills of understanding control limitation due to interactions, model uncertainties, nonminimum phase behavior, and unpredictable time variations, Design decentralized controllers, and understanding their limitations, Implementing decouplers to reduce the effect of interactions, and understanding their limitations.

Energy Saving of Three-phase Induction Motor Using Fuzzy Controller

This paper presents energy saving of three-phase induction motor, which is operated in regenerative mode. In this mode, the energy flows back into DC link voltage and causes to occur high voltage in capacitor that may be destroy the capacitor and switching component such an IGBT. The proposed method presents connection buck converter circuit between the rectifier diodes and the inverter, to control the voltage feeding into the inverter by using two fuzzy controllers. The first fuzzy controller will be managing the switching duty cycle of buck converter. The second fuzzy controller, which provide to control the switching component of braking circuit. The second controller will be synchronized with the first controller to balance the energy of the capacitor

Development of Redundant Bus Library for Arduino to Apply in SCADA System

In this paper, we developed the library for the microcontroller platform Arduino to apply in Modbus SCADA systems. This library allows Arduino board to communicate with RS-485 and use Modbus protocol which transmits data via a redundant bus. Experiments are conducted to compare the stability of data communication between a regular bus and a redundant bus which is the developed library. The results show the developed library Arduino board is able to communicate with redundant buses and more resistant to faults than conventional buses.

Algorithmic ADC using current mode without DAC

This paper presents a principle of analog to digital conversion (ADC) based on a current mode circuit without DAC. For example, in this circuit the input value can be converted to a 4 bit output at each moment, and multiple output bit numbers by serial connection. In this current mode, the active current mirror and current comparators control the reference current by adjusting the W/L ratio. Its feasibility agrees with simulation results by the PSPICE program. The circuit design used a CMOS 0.5 /spl mu/m process which is capable of converting 4 bits in 50 ns, with a power consumption of 0.127 mW, input current of 0-100 /spl mu/A and single 3 V supply. From simulation testing, the conversion rate is faster than other methods using the same parameters.

Design of PLC networks using remote I/O module based on controller area network

The design of the networks system through a controller area network (CAN) bus is presented. To distribute the control points with a long distance and located for the application to on-off electrical equipment by the remote I/O module. The controlling and communication between the programmable logic controller (PLC) and the remote I/O modules are used by the CAN bus serial communication. The experiment has been set up with the maximum of 32 remote I/O modules. Each remote I/Os are linked to the host PLC programmed for handling an interrupt request from any remote I/O independently. Therefore, the scanning time of the controller is not affected. By using this technique, the controller (PLC) can be efficiently applied to several hundred meters.

Retinal Image Enhancement in Multi-mode Histogram

Evaluation of a retinal image is widely employed to help doctors diagnose many diseases, such as diabetes or hypertension. From acquisition process, retinal images often have low grey level contrast and dynamic range. This paper proposes histogram analysis for solving the problems of retinal image enhancement. The proposed method uses fuzzy set to enhance the images by partitioning the image histogram to multi-modes with derivative equation. Each mode of the histogram is contrasted by finding the optimal crossover point of S-function with an index of fuzziness, which is designed for contrasting a field of view in the images. Our algorithm can achieve a number of properties of an importance for contrast stretching, such as compressed the noise in background and produced a high contrast in the field of view that provide feasibility in diagnosis from a retinal image.

BRM fast response DC motor speed control

The paper presents DC motor control by binary rate modulation (BRM). The 8 bit binary rate are controlled by an 8051 which in turn generates BRM by a PI (proportional integral) controller. The BRM method is efficient to control the supplied power with appropriate speed. The BRM method has low ripple, usually less than 5%, consequently, less noise with fast speed response when load changes.

Fault Tolerant Control System in Critical Process Based on Ethernet Network

The purpose of this paper is to study and develop the redundant control system for the critical process. The critical process means a high priority process which is very essential to the global system. When a fault condition occurs on such process, it affects to other processes. In this paper, the gas pressure process is used a case study. This system consists of dual redundant supervisory control system (HMI Station), dual redundant Ethernet network, triple redundant controller system and triple redundant filed signal. The experimental result is able to indicate some fault tolerance features. Our system can increase the reliability as well as the risk of fault of a whole system and apply to any high priority process appropriately