Steam temperature control of hydro-steam distillation process using self-tuning fuzzy fractional-order pi controller / Mazidah Tajjudin

Essential oil is the volatile extracts of botanical material and it is being used to promote health and human well-being because of its therapeutic effect. Essential oil is commercially extracted using distillation method which requires heat in order to break the oil glands during the process. Unfortunately, the oil quality obtained using this method is uncertain because chemical compounds in the oil are exposed to decomposition or transformation at high temperature. Hence, this research proposed a novel approach of closed-loop temperature control using a new self-tuning fuzzy fractional-order PI (FOPI) controller to realize low temperature essential oil extraction for a hydro-steam distillation process. The controller will regulate the steam temperature at a desired level to protect the oil from excessive heat. FOPI control technique is still at its infancy but the efficiency of the controller had been acknowledged by many researchers globally. FOPI controller is a generalized form of PI controller whereby it provides more degree of freedom that can guarantee better performances relative to the integer-order PI with the same controller parameters. Unfortunately, this characteristic leads to a more complex tuning methodology. Selftuning capability of fuzzy rules was found to facilitate this issue satisfactorily using only information about the output error and rate of the output error. The control performances were evaluated on a hydro-steam distillation process under set point change and load disturbance tests. The proposed controller was found to produce less overshoot and better steady-state response under both conditions compared to PI, FOPI, self-tuning fuzzy PI, and self-tuning PID pole-placement controllers. Essential oil quality assessment was also performed on citronella oil samples that were extracted at 85°C and 100 °C. Some differences had been observed in the sample extracted at lower temperature which produced lower refractive index and lower composition in citronellal but higher composition in citronellol and geraniol based on Gas chromatography - Mass spectrometry (GC-MS) analysis. This results show that the improvement proposed in this research is feasible towards improving the quality of essential oil extracted using hydro-steam distillation process

Fan beam optical tomography

The project describes the development of a fan beam optical tomography which applied infra red sources as the sensing element. The number of sensors used in the project is very limited and that gave a significant impact on the results obtained. However, the approach of the project is concentrated on the investigation of the performance and limitations of applying infra red sensors in process tomography. Numerous optical sources had been utilized based on the fact that it is the simplest method available up till now. The advantage of infra red sources compared to other optical sources was also discussed. The importance of identifying the sensor characteristics is crucial to make sure that it is the optimum instrument for our system. This report laid some important criteria that need to be considered upon applying infrared tomography system. The developed system used four pairs of infra red sensors to interrogate a pipe having a diameter of 50 mm. The image reconstruction algorithm was built based on the Linear Back Projection Algorithm. Several experiments had been carried out to evaluate the results. The results obtained were analyzed individually and concluded at the end of the report. Some suggestions were drawn which can be considered in order to improve the system performanc

Ultrasonic transmission-mode tomography imaging for liquid/gas two-phase flow

This paper details the development of noninvasive ultrasonic tomography for imaging liquid and gas flow. The transmission- mode approach has been used for sensing the liquid/ gas two-phase flow, which is a kind of strongly inhomogeneous medium. Sixteen pairs of ultrasonic sensors have been used. By using low excitation voltage of 20 V, fan-shaped beam ultrasonic transmitters will emit ultrasonic pulses to the receivers. The investigations were based on the transmission and the reception of ultrasonic sensors that were mounted circularly on the surface of the experimental vessel. The algorithms used to reconstruct the concentration profile for two-phase flow using a fan-shaped beam scanning geometry were presented. By using a hybridbinary reconstruction algorithm, real-time ultrasonic transmission- mode tomography has been developed. Experiments show that performance is acceptable with an image-reconstruction speed of 10 frames/s. The results of the experiments and possible future improvements were also discusse

Trajectory ZPETC design using comparing coefficients method: the studies on the effects of zero locations to tracking performance

Hydraulic actuator has been widely used in industrial applications because of it properties exhibiting linear movements, fast response, smooth reversal and accurate positioning of heavy load. The integration of electronic and hydraulic technology has becoming increasingly common for precision positioning. Reducing the position tracking error of the hydraulic actuator is a challenging task but advances in control strategies have resulted in cylinders that transmit high forces with a high degree of positioning accuracy. This paper presented the design of ZPETC parameters using comparing coefficients method and studies the effects of zero locations to tracking performance. The plant model used was approximated from input-output experimental data using Matlab system identification toolbox. In order to have 2 plant models with different zero locations, 2 different sampling times were used. The studies show that tracking performance is good when the zero is far from the unity circle

Forward and inverse problems solution : a review on ultrasonic tomography

This paper studies the solution for inverse and forward problems for an ultrasonic tomography. Transmission-mode approach has been used for sensing the liquid/gas two-phase flow, which is a kind of strongly inhomogeneous medium. The imaging technique for two-phase flow using fan-shaped beam scanning geometry was presented. In this work, the tomographic images are derived from Back-Projection Algorithm. Some of the results based on the Linear Back-Projection algorithm (LBP) and the Hybrid Reconstruction algorithm (HR) was also presented

PID Studies on Position Tracking Control of an Electro-Hydraulic Actuator

Abstract Despite the application of advanced control technique to imp rove the performance of electro-hydraulic position control, Proportional Integral Derivative (PID) control scheme seems able to produce satisfactory result. PID is preferable in industrial applications because it is simp le and robust. The main problem in its application is to tune the parameters to its optimu m values. This study will look into an optimization of PID parameters using Nelder-Mead (N-M) co mpare with self-tuning fuzzy approach for electro-hydraulic position control system. The electro-hydraulic system was represented by an Auto-regressive with Exogenous Input (ARX) model structure obtained through MATLAB System Identification Toolbo x. Second-order and third-order model of the system had been evaluated. Simu lation and real-t ime studies show that the output produced the best response in terms of transient speed and Root Mean Square Error (RM SE) performance criteria