Real-time digital tracking control of electro-hydraulic actuator using trajectory zero phase error tracking controller / Norlela Ishak

The experimental equipment Quarter Car System was used in the studies of comfort riding. This system consists of a metal framework with hydraulic absorber attached to a tyre assembly. In comfort riding studies, the tyre will move up and down and the absorber has to sustain and stabilize the movements. For comfort riding, a control system was designed to control the movement of absorber and stabilized in shortest possible time. The movement of tyre up and down represents the road profile to test the robustness of the absorber controller. The tyre movements to represent the road profile can be done by a position control electro-hydraulic actuator (EHA) system which was placed in vertical position. The control movement of cylinder rod will represent the required road profile for comfort riding studies. By implementing conventional Zero Phase Error Tracking Control (ZPETC) to control the cylinder rod movement will only accurate for slow movement but not for fast movement. This is due to low frequencies and small bandwidth limitation. High frequency operation is not applicable. Thus, this research work proposed a new development and implementation of digital tracking control using feedforward trajectory ZPETC to the EHA system that will provide better control of cylinder rod to emulate road profile for low and high frequency movements

Real-time digital tracking control of electro-hydraulic actuator using trajectory zero phase error tracking controller / Norlela Ishak

The experimental equipment Quarter Car System was used in the studies of comfort riding. This system consists of a metal framework with hydraulic absorber attached to a tyre assembly. In comfort riding studies, the tyre will move up and down and the absorber has to sustain and stabilize the movements. For comfort riding, a control system was designed to control the movement of absorber and stabilized in shortest possible time. The movement of tyre up and down represents the road profile to test the robustness of the absorber controller. The tyre movements to represent the road profile can be done by a position control electro-hydraulic actuator (EHA) system which was placed in vertical position. The control movement of cylinder rod will represent the required road profile for comfort riding studies. By implementing conventional Zero Phase Error Tracking Control (ZPETC) to control the cylinder rod movement will only accurate for slow movement but not for fast movement. This is due to low frequencies and small bandwidth limitation. High frequency operation is not applicable. Thus, this research work proposed a new development and implementation of digital tracking control using feedforward trajectory ZPETC to the EHA system that will provide better control of cylinder rod to emulate road profile for low and high frequency movements. The plant model was represented by ARX331 structure and identified from the open-loop test experimental data. The proposed controller was designed using three different controllers based on three separated methods such as RLS method, comparing coefficients method and Laurent series method. Simulation results showed that the RLS method was capable to produce satisfactory tracking performance even with small filter-order. High filter-order was required to produce the same satisfactory tracking performance using the comparing coefficients method and Laurent series method. Using the same filter-order, Laurent series method produced better tracking performance than comparing coefficients method. The simulation results were validated using the real-time control of the EHA system using Matlab and Simulink environment

Methodology approaches and challenges in population‐based longitudinal study of a neuroprotective model for healthy longevity

Aim: The 36‐month Long‐Term Research Grant Scheme project: Towards Usual Aging – Neuroprotective Model for Healthy Longevity among Malaysian Elderly was designed to address multidimensional aspects including psychosocial, biophysical health, nutrition and dietary pattern, and auditory and visual function to highlight the magnitude of these associations in a single study. Methods: A total of 2322 respondents aged ≥60 years were recruited at baseline using the multistage sampling method, followed up at 18 months and 36 months. Results: Response rates at baseline, 18 months and 36 months were 87.8%, 77.3% and 67.1%, respectively. At baseline, the prevalence of successful aging, usual aging and mild cognitive impairment was 11%, 73% and 16%, respectively. The prevalence of single and multimorbidity at baseline were 25.9% and 50.3%, respectively. The incidence rates of mild cognitive impairment at 18 months and 36 months were 6.5 and 5.6 per 100 person‐years. The incidence rates of multimorbidity at 18 months and 36 months were 23.7 and 21.5 per 100 person‐years, respectively. Conclusions: The Long‐Term Research Grant Scheme project: Towards Usual Aging study provides an opportunity to investigate the interactions between wide ranges of aspects of the older population in a nationally representative sample of the older population

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

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

PI-fuzzy logic control for 3 phase BLDC motor for electric vehicle application

Brushless DC motor has been widely used in electric vehicle because of its high performance and simplicity. However this motor is a multi-variable, non-linear system and easily can be influenced by the parameter variations and disturbances. The conventional controllers are unable to handle this problem. To overcome this problem a nonlinear PI-fuzzy logic controller is used to control the speed of electric vehicle traction motor. The development of this control strategy is presented in this paper. The proposed controller has simple structure and also due to its modest fuzzy rule in rulebase is relatively easy for implementation. The control is performed by Matlab/Simulink software. The simulation test results have been satisfactory in both steady and transient states. This controller has high accuracy, suitable performance, high robustness and high tracking efficiency