Rini Akmeliawati is currently a full Professor at the Department of Mechatronics Engineering, International Islamic University Malaysia (IIUM). She obtained the Bachelor of Engineering (Honours) in Electrical Engineering from Royal Melbourne Institute of Technology (RMIT) University, Australia in 1997, and her PhD in Electrical and Electronic Engineering from the University of Melbourne, Australia in 2002. She has been a full Professor in IIUM since 2012. She joined the Department as an Associate Professor in 2008. She was a lecturer at RMIT University (2001-2004) and Monash University (2004-2008). Her main research interests include nonlinear control systems theory and applications, intelligent and Mechatronics systems, signal and image processing.
The success of model-based flight control law design for autonomous helicopter is largely depende... more The success of model-based flight control law design for autonomous helicopter is largely dependent on the availability of reliable model of the system. Considering the complexity of the helicopter dynamics, and inherent difficulty involves with physical measurement of the system parameters, the grey modeling approach which involves the development of parameterized model from first principles and estimation of these parameters using system identification (sysID) technique has been proposed in the literatures. Prediction Error Modeling (PEM) algorithm has been identified as an effective system identification technique. However, application of this method to complex system like helicopter is not a trivial exercise due to inherent coupling in the system states and the challenges associated with parameter initialization in PEM algorithm. In this work, an effective procedure in application of PEM algorithm available in MATLAB toolbox is presented for small scale helicopter using real-tim...
Sign language is the verbal language for the people who have hearing impairment. Those people who... more Sign language is the verbal language for the people who have hearing impairment. Those people who have those kinds of problems are widely known as the deaf people. Basically the word of deaf is referred into two; the Deaf (with capital D) is the hearing impairment person who understands sign language and the deaf (with small d) is the person who does not have capability in understanding the sign language. In this article, the "deaf' (with small d) will be used to cover the entire people with hearing impairment and disability
Practical application of SVR in nonparametric modeling requires not only achievement of acceptabl... more Practical application of SVR in nonparametric modeling requires not only achievement of acceptable model accuracy but also optimal reduction of the model complexity in terms of the associated support vectors. Attaining these performance metrics is not only challenging due to inherently conflicting nature of the duo performances, but also as a result of several structural parameters needed to be tuned in SVR deployment. In order to address this problem, a hybrid algorithm of SVR based on Multi Objective Differential Evolution (MODE-SVR) is proposed to search for the SVR structural parameters that provides Pareto-based optimal solutions for both model complexity and accuracy. The proposed algorithm is evaluated on nonparametric model of a UAV helicopter yaw dynamics. Performance analysis and comparative study with an existing method in MATLAB shows the effectiveness of the proposed hybrid algorithm. This is expected to simplify and enhance the practical application of SVR in machine l...
This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can ... more This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can perform Malaysian Sign Language (MSL). The study is considered as the first attempt to ease the means of communication between the general community and the hearing-impaired individuals in Malaysia. The signed motions performed by the developed robot in this work can be done by two hands. The designed system, unlike previously conducted work, includes a speech recognition system that can feasibly integrate with the controlling platform of the robot. Furthermore, the design of the system takes into account the grammar of the MSL which differs from that of Malay spoken language. This reduces the redundancy and makes the design more efficient and effective. The robot hands are built with detailed finger joints. Micro servo motors, controlled by Arduino Mega, are also loaded to actuate the relevant joints of selected alphabetical and numerical signs as well as phrases for emergency contexts ...
This paper presents a robust state feedback controller tuning via constrained optimization using ... more This paper presents a robust state feedback controller tuning via constrained optimization using DE (differential evolution). The controller gain is optimized based on linear state-space model of the plant such that the closed-loop system achieves maximum stability radius. The desired control performance is specified by assigning closed-loop poles region which is handled as a constraint in the optimization. The proposed controller design technique is applied to a longitudinal cruise control of a small scale helicopter. The control of small-scale helicopter is a MIMO problem which increases the complexity of the controller design task. The simulation result is shown to evaluate the effectiveness of the proposed controller design technique. Comparison with that of conventional LQR-based controller is also presented.
Malaysian Sign Language (MSL) recognition system is a choice of augmenting communication between ... more Malaysian Sign Language (MSL) recognition system is a choice of augmenting communication between the hearing-impaired and hearing communities in Malaysia. Automatic translators can play an important role as alternative communication method for the hearing people to understand the hearing impaired ones. Automatic Translation using bare hands with natural gesture signing is a challenge in the field of machine learning. Researchers have used electronic and coloured gloves to solve mainly three issues during the preprocessing steps before the singings’ recognition stage. First issue is to differentiate the two hands from other objects. This is referred to as hand detection. The second issue is to describe the detected hand and its motion trajectory in very descriptive details which is referred to as feature extraction stage. The third issue is to find the starting and ending duration of the sign (transitions between signs). This paper focuses on the second issue, the feature extraction ...
This paper presents a thorough review on the system identification techniques applied to flapping... more This paper presents a thorough review on the system identification techniques applied to flapping wing micro air vehicles (FWMAVs). The main advantage of this work is to provide a solid background and domain knowledge of system identification for further investigations in the field of FWMAVs. In the system identification context, the flapping wing systems are first categorized into tailed and tailless MAVs. The most recent developments related to such systems are reported. The system identification techniques used for FWMAVs can be classified into time-response based identification, frequency-response based identification, and the computational fluid-dynamics based computation. In the system identification scenario, least mean square estimation is used for a beetle mimicking system recognition. In the end, this review work is concluded and some recommendations for the researchers working in this area are presented.
International Journal of Distributed Sensor Networks
Diabetes mellitus is a persistent metabolic syndrome caused by impaired capability of the body’s ... more Diabetes mellitus is a persistent metabolic syndrome caused by impaired capability of the body’s production and usage of insulin. This impaired capability results in chronic hyperglycaemia, the elevated glucose concentration in the bloodstream, which may lead to many incurable complications. To escape this dire situation, a proper model-based exogenous infusion of insulin bolus is required, which is usually established via different feedback control strategies. In this article, the authors present a mathematical model–based robust integral sliding mode control approach for stabilization of internal glucose–insulin regulatory system in type-1 diabetic patient. Since the state variables of the system are not directly available to the controller, a uniform exact differentiator observer is employed to accomplish the aforementioned task. In the proposed control law, the incorporation of integral term in the switching manifold eliminates the reaching phase, which causes the sliding mode t...
International Journal of Robotics and Mechatronics
This paper presents a robust state feedback controller tuning via constrained optimization using ... more This paper presents a robust state feedback controller tuning via constrained optimization using DE (differential evolution). The controller gain is optimized based on the plant model such that the closed-loop system achieves maximum stability radius. The desired control performance is specified by assigning closed-loop poles region which is handled as a constraint in the DE-based optimization. The proposed controller design technique is applied to a longitudinal cruise control of a small-scale helicopter. The control of small-scale helicopter is a MIMO problem which increases the complexity of the controller design task. The proposed controller design attempts to simplify this complicated task where the automated design is employed via DE-based modern optimization. The effectiveness of the proposed controller design technique is presented by comparing its performance with that of conventional LQR-based controllers in computer simulation.
Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to pro... more Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC) used in conventional LVADs, we developed a preload-based Starling-like controller (SLC). The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text]) with respect to mean left ventricular end diastolic pressure (PLVEDm) as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm) and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC). The root mean squared hemodynamic deviation (RMSHD) metric was used to assess the clinical acceptability of each controller based on pre-defined hemodynamic limits. We also compared the in-si...
This paper proposes a practical design method for the robust control of a class of MIMO nonlinear... more This paper proposes a practical design method for the robust control of a class of MIMO nonlinear plants operating under model uncertainties and matched disturbances where the only available information for feedback are the outputs of the plant. A neural networks based dynamic integral sliding mode control (NNDISMC) with output differentiator observer is developed for the considered class. This NNDISMC approach utilizes the robust output differentiation observer for the higher derivative estimation and neural networks to estimate the nonlinear functions which are assumed unknown. Having estimated the unknown derivatives and uncertain functions, an integral manifold based on the estimated states is designed and a control law is proposed which confirms the sliding mode enforcement across the designed integral manifold from the very start of the process. The overall robustness of the controller is guaranteed by using the neural networks, differentiator observer and dynamic integral control law in a closed loop. The closed loop stability analysis is presented in detail, and the asymptotic convergence of the system states to the equilibrium is confirmed. The proposed method is very practical and plays a very significant role in the robust control of electromechanical systems, such as robotic manipulators, unmanned air vehicles and underwater vehicles. The simulation results on a robotic manipulator are presented to demonstrate the effectiveness of the proposed method.
The success of model-based flight control law design for autonomous helicopter is largely depende... more The success of model-based flight control law design for autonomous helicopter is largely dependent on the availability of reliable model of the system. Considering the complexity of the helicopter dynamics, and inherent difficulty involves with physical measurement of the system parameters, the grey modeling approach which involves the development of parameterized model from first principles and estimation of these parameters using system identification (sysID) technique has been proposed in the literatures. Prediction Error Modeling (PEM) algorithm has been identified as an effective system identification technique. However, application of this method to complex system like helicopter is not a trivial exercise due to inherent coupling in the system states and the challenges associated with parameter initialization in PEM algorithm. In this work, an effective procedure in application of PEM algorithm available in MATLAB toolbox is presented for small scale helicopter using real-tim...
Sign language is the verbal language for the people who have hearing impairment. Those people who... more Sign language is the verbal language for the people who have hearing impairment. Those people who have those kinds of problems are widely known as the deaf people. Basically the word of deaf is referred into two; the Deaf (with capital D) is the hearing impairment person who understands sign language and the deaf (with small d) is the person who does not have capability in understanding the sign language. In this article, the "deaf' (with small d) will be used to cover the entire people with hearing impairment and disability
Practical application of SVR in nonparametric modeling requires not only achievement of acceptabl... more Practical application of SVR in nonparametric modeling requires not only achievement of acceptable model accuracy but also optimal reduction of the model complexity in terms of the associated support vectors. Attaining these performance metrics is not only challenging due to inherently conflicting nature of the duo performances, but also as a result of several structural parameters needed to be tuned in SVR deployment. In order to address this problem, a hybrid algorithm of SVR based on Multi Objective Differential Evolution (MODE-SVR) is proposed to search for the SVR structural parameters that provides Pareto-based optimal solutions for both model complexity and accuracy. The proposed algorithm is evaluated on nonparametric model of a UAV helicopter yaw dynamics. Performance analysis and comparative study with an existing method in MATLAB shows the effectiveness of the proposed hybrid algorithm. This is expected to simplify and enhance the practical application of SVR in machine l...
This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can ... more This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can perform Malaysian Sign Language (MSL). The study is considered as the first attempt to ease the means of communication between the general community and the hearing-impaired individuals in Malaysia. The signed motions performed by the developed robot in this work can be done by two hands. The designed system, unlike previously conducted work, includes a speech recognition system that can feasibly integrate with the controlling platform of the robot. Furthermore, the design of the system takes into account the grammar of the MSL which differs from that of Malay spoken language. This reduces the redundancy and makes the design more efficient and effective. The robot hands are built with detailed finger joints. Micro servo motors, controlled by Arduino Mega, are also loaded to actuate the relevant joints of selected alphabetical and numerical signs as well as phrases for emergency contexts ...
This paper presents a robust state feedback controller tuning via constrained optimization using ... more This paper presents a robust state feedback controller tuning via constrained optimization using DE (differential evolution). The controller gain is optimized based on linear state-space model of the plant such that the closed-loop system achieves maximum stability radius. The desired control performance is specified by assigning closed-loop poles region which is handled as a constraint in the optimization. The proposed controller design technique is applied to a longitudinal cruise control of a small scale helicopter. The control of small-scale helicopter is a MIMO problem which increases the complexity of the controller design task. The simulation result is shown to evaluate the effectiveness of the proposed controller design technique. Comparison with that of conventional LQR-based controller is also presented.
Malaysian Sign Language (MSL) recognition system is a choice of augmenting communication between ... more Malaysian Sign Language (MSL) recognition system is a choice of augmenting communication between the hearing-impaired and hearing communities in Malaysia. Automatic translators can play an important role as alternative communication method for the hearing people to understand the hearing impaired ones. Automatic Translation using bare hands with natural gesture signing is a challenge in the field of machine learning. Researchers have used electronic and coloured gloves to solve mainly three issues during the preprocessing steps before the singings’ recognition stage. First issue is to differentiate the two hands from other objects. This is referred to as hand detection. The second issue is to describe the detected hand and its motion trajectory in very descriptive details which is referred to as feature extraction stage. The third issue is to find the starting and ending duration of the sign (transitions between signs). This paper focuses on the second issue, the feature extraction ...
This paper presents a thorough review on the system identification techniques applied to flapping... more This paper presents a thorough review on the system identification techniques applied to flapping wing micro air vehicles (FWMAVs). The main advantage of this work is to provide a solid background and domain knowledge of system identification for further investigations in the field of FWMAVs. In the system identification context, the flapping wing systems are first categorized into tailed and tailless MAVs. The most recent developments related to such systems are reported. The system identification techniques used for FWMAVs can be classified into time-response based identification, frequency-response based identification, and the computational fluid-dynamics based computation. In the system identification scenario, least mean square estimation is used for a beetle mimicking system recognition. In the end, this review work is concluded and some recommendations for the researchers working in this area are presented.
International Journal of Distributed Sensor Networks
Diabetes mellitus is a persistent metabolic syndrome caused by impaired capability of the body’s ... more Diabetes mellitus is a persistent metabolic syndrome caused by impaired capability of the body’s production and usage of insulin. This impaired capability results in chronic hyperglycaemia, the elevated glucose concentration in the bloodstream, which may lead to many incurable complications. To escape this dire situation, a proper model-based exogenous infusion of insulin bolus is required, which is usually established via different feedback control strategies. In this article, the authors present a mathematical model–based robust integral sliding mode control approach for stabilization of internal glucose–insulin regulatory system in type-1 diabetic patient. Since the state variables of the system are not directly available to the controller, a uniform exact differentiator observer is employed to accomplish the aforementioned task. In the proposed control law, the incorporation of integral term in the switching manifold eliminates the reaching phase, which causes the sliding mode t...
International Journal of Robotics and Mechatronics
This paper presents a robust state feedback controller tuning via constrained optimization using ... more This paper presents a robust state feedback controller tuning via constrained optimization using DE (differential evolution). The controller gain is optimized based on the plant model such that the closed-loop system achieves maximum stability radius. The desired control performance is specified by assigning closed-loop poles region which is handled as a constraint in the DE-based optimization. The proposed controller design technique is applied to a longitudinal cruise control of a small-scale helicopter. The control of small-scale helicopter is a MIMO problem which increases the complexity of the controller design task. The proposed controller design attempts to simplify this complicated task where the automated design is employed via DE-based modern optimization. The effectiveness of the proposed controller design technique is presented by comparing its performance with that of conventional LQR-based controllers in computer simulation.
Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to pro... more Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC) used in conventional LVADs, we developed a preload-based Starling-like controller (SLC). The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text]) with respect to mean left ventricular end diastolic pressure (PLVEDm) as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm) and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC). The root mean squared hemodynamic deviation (RMSHD) metric was used to assess the clinical acceptability of each controller based on pre-defined hemodynamic limits. We also compared the in-si...
This paper proposes a practical design method for the robust control of a class of MIMO nonlinear... more This paper proposes a practical design method for the robust control of a class of MIMO nonlinear plants operating under model uncertainties and matched disturbances where the only available information for feedback are the outputs of the plant. A neural networks based dynamic integral sliding mode control (NNDISMC) with output differentiator observer is developed for the considered class. This NNDISMC approach utilizes the robust output differentiation observer for the higher derivative estimation and neural networks to estimate the nonlinear functions which are assumed unknown. Having estimated the unknown derivatives and uncertain functions, an integral manifold based on the estimated states is designed and a control law is proposed which confirms the sliding mode enforcement across the designed integral manifold from the very start of the process. The overall robustness of the controller is guaranteed by using the neural networks, differentiator observer and dynamic integral control law in a closed loop. The closed loop stability analysis is presented in detail, and the asymptotic convergence of the system states to the equilibrium is confirmed. The proposed method is very practical and plays a very significant role in the robust control of electromechanical systems, such as robotic manipulators, unmanned air vehicles and underwater vehicles. The simulation results on a robotic manipulator are presented to demonstrate the effectiveness of the proposed method.
The present study investigates the response of implantable rotary blood pump (IRBP)-assisted pati... more The present study investigates the response of implantable rotary blood pump (IRBP)-assisted patients to exercise and head-up tilt (HUT), as well as the effect of alterations in the model parameter values on this response, using validated numerical models. Furthermore, we comparatively evaluate the performance of a number of previously proposed physiologically responsive controllers, including constant speed, constant flow pulsatility index (PI), constant average pressure difference between the aorta and the left atrium, constant average differential pump pressure, constant ratio between mean pump flow and pump flow pulsatility (ratioPI or linear Starling-like control), as well as constant left atrial pressure inline image control, with regard to their ability to increase cardiac output during exercise while maintaining circulatory stability upon HUT. Although native cardiac output increases automatically during exercise, increasing pump speed was able to further improve total cardiac output and reduce elevated filling pressures. At the same time, reduced venous return associated with upright posture was not shown to induce left ventricular (LV) suction. Although inline image control outperformed other control modes in its ability to increase cardiac output during exercise, it caused a fall in the mean arterial pressure upon HUT, which may cause postural hypotension or patient discomfort. To the contrary, maintaining constant average pressure difference between the aorta and the left atrium demonstrated superior performance in both exercise and HUT scenarios. Due to their strong dependence on the pump operating point, PI and ratioPI control performed poorly during exercise and HUT. Our simulation results also highlighted the importance of the baroreflex mechanism in determining the response of the IRBP-assisted patients to exercise and postural changes, where desensitized reflex response attenuated the percentage increase in cardiac output during exercise and substantially reduced the arterial pressure upon HUT.
In this study, we evaluate a preload-based Starling-like controller for implantable rotary blood ... more In this study, we evaluate a preload-based Starling-like controller for implantable rotary blood pumps (IRBPs) using left ventricular end-diastolic pressure (PLVED) as the feedback variable. Simulations are conducted using a validated mathematical model. The controller emulates the response of the natural left ventricle (LV) to changes in PLVED. We report the performance of the preload-based Starling-like controller in comparison with our recently designed pulsatility controller and constant speed operation. In handling the transition from a baseline state to test states, which include vigorous exercise, blood loss and a major reduction in the LV contractility (LVC), the preload controller outperformed pulsatility control and constant speed operation in all three test scenarios. In exercise, preload-control achieved an increase of 54% in mean pump flow () with minimum loading on the LV, while pulsatility control achieved only a 5% increase in flow and a decrease in mean pump speed. In a hemorrhage scenario, the preload control maintained the greatest safety margin against LV suction. PLVED for the preload controller was 4.9 mmHg, compared with 0.4 mmHg for the pulsatility controller and 0.2 mmHg for the constant speed mode. This was associated with an adequate mean arterial pressure (MAP) of 84 mmHg. In transition to low LVC, for preload control remained constant at 5.22 L/min with a PLVED of 8.0 mmHg. With regards to pulsatility control, fell to the nonviable level of 2.4 L/min with an associated PLVED of 16 mmHg and a MAP of 55 mmHg. Consequently, pulsatility control was deemed inferior to constant speed mode with a PLVED of 11 mmHg and a of 5.13 L/min in low LVC scenario. We conclude that pulsatility control imposes a danger to the patient in the severely reduced LVC scenario, which can be overcome by using a preload-based Starling-like control approach.
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Papers by Rini Akmeliawati