RNA codons govern the mechanism of protein folding through the shape memory effect

The complex protein folding mechanism had been researched during the past halfcentury, given its potential to offer cures for illnesses caused by viruses and protein misfolding. However, to date, the work remains inadequately successful and mastered, provoking the question of whether researchers are looking at the wrong place for the answer. Specifically, can RNA codons define the protein folding mechanism? This review will first present existing mechanisms for protein folding and their limitations. Then, the logic and evidence supporting the use of a protein folding mechanism governed by RNA codons will be presented. This paper explains protein folding as a shape-memory phenomenon wherein the protein chain memorises the native folded structure. Under the right chemical environment, the protein chain will fold back into its native memorised structure. The RNA codon is the imprint for the natively folded protein shape memory, responsible for programming the native folded structure shape memory onto the protein chain

Design, Fabrication, Modeling and Control of Artificial Muscle Actuated Wrist Joint System

This research dissertation presents the design, fabrication, modeling and control of an artificial muscle (AM) actuated wrist joint system, i.e., a thermoelectric (TEM) antagonistically driven shape memory alloy (SMA) actuator, to mimic the muscle behavior of human beings. In the developed AM based wrist joint system, the SMA, exhibiting contraction and relaxation corresponding to its temperature, is utilized as the actuator in the AM. Similar to the nerve stimulation, TEM is introduced to provide heat stimulation to the SMA, which involves heating and cooling of the SMA. SMA possesses superelastic behavior that provides a large force over its weight and effective strain in practical applications. However, such superior material has been underutilized due to its high nonlinear hysteresis behavior, strongly affected by the loading stress. Using the data obtained from the experiments, based on the Prandtl-Ishlinskii (PI) model, a Stress-Dependent Generalized Prandtl-Ishlinskii (SD-GPI) model is proposed, which can describe the hysteresis behavior of the SMA under the influence of various stresses. The parameters of the SD-GPI models at various stresses are obtained using a fitting function from the Matlab. The simulation results of the SD-GPI showed that prediction error is achieved at mean values of ±2% and a standard deviation of less than 7%. Meanwhile, the TEM model is also developed based on the heat balance theory. The model parameters are identified via experimental data using Range-Kutta fourth order integration equation and Matlab curve fitting function. The TEM model has shown a satisfactory temperature prediction. Then, by combining the obtained two models, an integrated model is developed to describe the whole dynamics of the wrist joint system. To control the SMA actuated wrist system, the SD-GPI inverse hysteresis compensator is developed to mitigate the hysteresis effect. However, such a compensator shows errors in compensating the hysteresis effect. Therefore, the inverse hysteresis compensator error and the system tracking error are analyzed, and the adaptive back-stepping based control approach is adopted to develop the inverse based adaptive control for the antagonistic AM wrist joint. Subsequently, a corresponding control law is developed for the TEM system to generate the required temperature obtained from the adaptive controller. Simulations verified the developed approach. Finally, experiments are conducted to verify the proposed system. Input sinusoidal signal with frequency 0.1rad/s and amplitude of ±0.524rad (±30°) is applied to the wrist joint system. Experimental results verified that the TEMs antagonistically driven SMA actuators for artificial muscle resembling wrist joint has been successfully achieved

Stress-dependent generalized Prandtl–Ishlinskii hysteresis model of a NiTi wire with superelastic behavior

The extremely useful superelastic behavior of NiTi has been poorly explored because of the limited number of models that can describe the complete hysteretic behavior of NiTi, including a superelastic condition that strongly depends on the applied stress. This paper presents the development of a stress-dependent phenomenological model of NiTi by modifying the existing generalized Prandtl–Ishlinskii (GPI) model. The parameters of the envelop function of the GPI model’s play operator are reformulated as quadratic functions of the applied stress. The stress-dependent GPI model can satisfactorily predict the output strain of a NiTi #6 wire under temperature and stress variation

Autonomous underwater vehicle Manoeuvrability studies

This research project is aimed to understanding the manoeuvrability of AUV and develop mathematical model to describe behaviour of vehicle interaction with the operating environment. A hovering type of AUV was defined base on the operation need of the AUV where it is likely to be applied in underwater research and exploring activities. Due to the increase demand of AUV, major efforts have been made in developing AUV in overcoming the challenging scientific and engineering problems caused by the unstructured ocean environment. The theoretical modeling of the AUV had being developed via Newtonian mechanics approach and the 6-DOF dynamic equations of motion are derived throughout the process. The governing equations mainly constitute terms of rigid body inertia matrix, hydrodynamic damping matrix, restoring forces and moments, environmental and propulsion forces and moments. Subsequently, a feasible 3-D solid modeling of the AUV had been designed through iterative method with CAD and CAE verification. Fluid interactions and manoeuvrability design analysis was achieved through implementation of CFD tool, COSMOSFloWorks. The theoretical modeling developed had been simplified under several relevant assumptions and the second order non-linear differential . equation solved using the programming software MA TI.AB to investigate the translational motion of the vehicle in the surging direction. The result from the model is the AUV motion relation, drag force and lift coefficient that could be utilized in the further AUV prototype development. The solid 3D design of the AUV had been achieved through spiral design process of iterative method. The method involves design statement, preliminary design, conceptual design and detailed design. Fundamental hydrodynamic knowledge had been applied to facilitate the design of the AUV. The optimum thruster location had been identified and the optimum design achieved. The scope of physical solid modeling had been effectively implemented via CAD software. SolidWorks licence by Universiti Malaysia Sabah had been utilized as the CAD platform in developing the AUV 3D model Stalling phenomena had also been identified as 15° through simulation software, COSMOSFloWorks. The stall pitching angle defines where the unstable manoeuvring of the vehicle will occur. COSMOSFloWorks also had been utilized to examine the effect of current velocities towards the AUV lift and drag coefficients. The simulation was conducted at various Reynolds number and various pitching angles. The investigation has found that the lift coefficient and drag coefficient increases as the pitching angle increases, but the considered range of Reynolds number had no significant effect on these hydrodynamic coefficients. These results were important for the design of better guidance and control systems for the AUV to achieve effective manoeuvring in current flow environment

Adaptive route optimization for mobile robot navigation using evolutionary algorithm

As technologies are advancing, demand for an intelligent mobile robot also increases. In autonomous robot design, the main problem faced by researchers is the path planning of mobile robot. Various kind of path planning algorithm was introduced in the past, but no algorithm has absolute superior towards the others algorithm. Classical methods like artificial potential field, grid search, and visual method have been easily overtaken by artificial intelligence due to its adaptability and ability to learn from the past mistakes or experience. For example, Ant Colony Optimization (ACO) is an optimization algorithm based on swarm intelligence which is widely used to solve path planning problem. However, the performance of ACO is highly dependent on the selection of its parameters. In this paper, the proposed adaptive ACO introduced two different ants, namely abnormal ant and random ant into the normal ACO to increase its global search ability and reduce the high convergence rate of ACO. Conventional ACO and adaptive ACO are compared in this paper and the results showed that adaptive ACO has better performance than conventional ACO in path planning

A short review on vision-based object grasping automation with QR code

Rapid development in technologies has improved our quality of life at the same time application of automation into daily activities is becoming an imperative. The online order-picking system is foreseen to be a new normal of life and thus this paper reviews various past researches with related technologies. Few topics mainly on the vision-based grasping automation and monocular vision system using QR code as labels or markers is reviewed. The application of different types of grasping automation in variety field is studied and it shows that an Eye In Hand (EIH) type grasping automation, which the camera sensor is placed together with the robot arm's end, is suitable to be applied into an order-picking system. Thereafter, the monocular vision-based system is also reviewed. Studies found that monocular system is an effective method with low cost and easy installation process. Besides, monocular vision-based automation can operate at high accuracy and efficiency, with the aid of artificial markers such as QR code. QR code technology has been widely applied including products identification, item tracing, and manufacturing management. Additionally, QR codes can be used as markers for picking and packaging products in warehouse. However, limited research is observed using vision-based grasping automation system with QR code markers. Thus, a new research direction of monocular vision-based grasping automation using QR code is expected and suggestive

Numerical Computation-Based Position Estimation for QR Code Object Marker: Mathematical Model and Simulation

Providing position and orientation estimations from a two-dimensional (2D) image is challenging, as such images lack depth information between the target and the automation system. This paper proposes a numerical-based monocular positioning method to determine the position and orientation of a single quick response (QR) code object marker. The three-dimensional (3D) positional information can be extracted from the underdetermined system using the QR code’s four vertices as positioning points. This method uses the fundamental principles of the pinhole imaging theory and similar triangular rules to correspond the QR code’s corner points in a 3D environment to the 2D image. The numerical-based model developed with suitable guessing parameters and correct updating rules successfully determines the QR code marker’s position. At the same time, an inversed rotation matrix determines the QR code marker’s orientation. Then, the MATLAB platform simulates the proposed positioning model to identify the maximum rotation angles detectable at various locations using a single QR code image with the known QR code’s size and the camera’s focal length. The simulation results show that the proposed numerical model can measure the position and orientation of the tilted QR code marker within 30 iterations with great accuracy. Additionally, it can achieve no more than a two-degree angle calculation error and less than a five millimeter distance difference. Overall, more than 77.28% of the coordinate plane simulated shows a converged result. The simulation results are verified using the input value, and the method is also capable of experimental verification using a monocular camera system and QR code as the landmark

Numerical Computation-Based Position Estimation for QR Code Object Marker: Mathematical Model and Simulation

Providing position and orientation estimations from a two-dimensional (2D) image is challenging, as such images lack depth information between the target and the automation system. This paper proposes a numerical-based monocular positioning method to determine the position and orientation of a single quick response (QR) code object marker. The three-dimensional (3D) positional information can be extracted from the underdetermined system using the QR code’s four vertices as positioning points. This method uses the fundamental principles of the pinhole imaging theory and similar triangular rules to correspond the QR code’s corner points in a 3D environment to the 2D image. The numerical-based model developed with suitable guessing parameters and correct updating rules successfully determines the QR code marker’s position. At the same time, an inversed rotation matrix determines the QR code marker’s orientation. Then, the MATLAB platform simulates the proposed positioning model to identify the maximum rotation angles detectable at various locations using a single QR code image with the known QR code’s size and the camera’s focal length. The simulation results show that the proposed numerical model can measure the position and orientation of the tilted QR code marker within 30 iterations with great accuracy. Additionally, it can achieve no more than a two-degree angle calculation error and less than a five millimeter distance difference. Overall, more than 77.28% of the coordinate plane simulated shows a converged result. The simulation results are verified using the input value, and the method is also capable of experimental verification using a monocular camera system and QR code as the landmark