Ishak Aris

Artificial neural network-based kinematics Jacobian solution for serial manipulator passing through singular configurations

Singularities and uncertainties in arm configurations are the main problems in kinematics robot control resulting from applying robot model, a solution based on using Artificial Neural Network (ANN) is proposed here. The main idea of this approach is the use of an ANN to learn the robot system characteristics rather than having to specify an explicit robot system model. Despite the fact that this is very difficult in practice, training data were recorded experimentally from sensors fixed on each joint for a six Degrees of Freedom (DOF) industrial robot. The network was designed to have one hidden layer, where the input were the Cartesian positions along the X, Y and Z coordinates, the orientation according to the RPY representation and the linear velocity of the end-effector while the output were the angular position and velocities for each joint, In a free-of-obstacles workspace, off-line smooth geometric paths in the joint space of the manipulator are obtained. The resulting network was tested for a new set of data that has never been introduced to the network before these data were recorded in the singular configurations, in order to show the generality and efficiency of the proposed approach, and then testing results were verified experimentally.

An Internet-based blood pressure monitoring system for patients

We developed a personal blood pressure monitoring system for patients with hypertension or hypotension. The system can be used to measure a patients blood pressure at home and to transmit the data automatically to a hospital database via the Internet. The accuracy of blood pressure readings using the system was assessed by comparison with readings from a standard digital sphygmomanometer in four subjects. The measurement error for the systolic readings was 1.7-2.7% and for the diastolic readings 2.7-3.2%. The system therefore appears to be a promising means of assessing blood pressure remotely.

Design of a micro-UART for SoC application

Abstract This paper presents the design of a universal asynchronous receiver and transmitter (UART), which is fully functional and synthesizeable. Due to its modularity, configurability and extremely compact size, the proposed UART is named as micro-UART and it is ideal for system-on-a-chip (SoC) application. The core is usable as an intellectual property. Verilog hardware description language (HDL) in the Alteras MAX-PLUS II environment has been used for its design, compilation and simulation. The UART has been implemented using Alteras FPGA technology.

Design of an ultra high speed AES processor for next generation IT security

The Advanced Encryption Standard (AES) has added new dimension to cryptography with its potentials of safeguarding the IT systems. This paper presents the design of an ultra high speed AES processor to generate cryptographically secured information at a rate of multi-ten Gbps. The proposed design addresses the next generation IT security requirements: the resistance against all crypto-analytical attacks and high speed with low latency. This work optimizes AES algorithm to eliminate algebraic operations from the datapath, which contributes to achieve ultra high speed and to reduce the latency. The AES processor is designed using Verilog HDL and then simulated using FPGA platform. The performance of the processor is compared with that of other researchers in terms of speed and latency, which shows its superiority over them. The soft core can be reused to convert it to ASIC to achieve much better performance.

Knowledge Discovery in Distance Relay Event Report: A Comparative Data-Mining Strategy of Rough Set Theory With Decision Tree

A protective relay performance analysis is only feasible when the hypothesis of expected relay operation characteristics as decision rules is established as the knowledge base. This has been meticulously accomplished by soliciting the relay knowledge domain from protection experts who are usually constrained by their experience and expertise. Manually analyzing an event report is also cumbersome due to the tremendous amount of data to be perused. This paper addresses these issues by intelligently divulging the knowledge hidden in the relay recorded event report using a data-mining strategy based on rough set theory and a rule-quality measure under supervised learning to discover the relay decision algorithm and association rule. The high prediction accuracy rate and the close-to-unity areas under ROC curve value of the relay operating characteristic curve of the discovered relay decision algorithm verifies its generalized ability to predict trip status in an expert system of relay performance analysis. The relay association rule that was subsequently discovered by using the rule-quality analysis had also been verified as being a reliable hypothesis of the relay operation characteristics. This hypothesis helps the protection engineers understand the behavior of the distance relay. These rules would then be compared with and validated by benchmarking decision-tree-based data-mining analysis.

Challenges and directions for testing IC

In todays semiconductor world, integration technology is improving and refining dramatically. With the continuous increase of integration densities and complexities, the problem of integrated circuit (IC) testing has become much more acute. IC testing is now no more a back-end issue, rather it has become a front-end burning issue, which needs an economic solution with reliable performance. Otherwise all the benefits of semiconductor technology would be meaningless. A roadmap of semiconductor technology in the context of IC testing is shown in this paper. Researchers and manufacturers can get to know current challenges and directions of IC testing through this discussion.

Design and analysis of a single phase slot-less permanent magnet generator

This paper discussed on the design and analysis of a permanent magnet generator (PMG). Basically, the PMG is a slot-less type topology and operated in a single-phase. The flux direction in the air gap is in radial. It was developed for energizing the linear motor in pruner application. Due to this application, a compact generator that can produce 500 W output power is required since the overall size of the PMG is important. Permeance analysis method (PAM) and finite element method (FEM) were used to analyzed the PMG performance characteristic in addition of measurement of the PMG prototype. Various numbers of poles and rotor size were considered during this analysis. The results show that the slot-less PMG with stator size of 104 mm will produce maximum power of 650 W when it has 6-poles with rotor radius is 37 mm. Based on the results, the calculation method using PAM shows good agreement with measurement and simulation.

An adaptive learning algorithm for controlling a two-degree-of-freedom serial ball-and-socket actuator

Abstract This article presents the development and implementation of an artificial neural network (ANN) for controlling a new two-degree-of-freedom (2DOF) serial ball-and-socket actuator. The ANN is a well-known algorithm for simulating the ability of the human brain to learn and predict sets of information. In this approach, ANN will learn the control parameters to obtain the angular displacement, angular velocity, and angular acceleration of the end-effector without any prior knowledge of the actuator. The ball-and-socket actuator has been proposed as an alternative actuator to the conventional one-degree-of-freedom (1DOF) revolute actuator. The actuator was fabricated from a ball-and-socket joint powered by two electrohydraulic cylinders. Experimental control data had been collected manually and provided for ANN to learn in off-line mode. The training process was carried out to build control knowledge. Thus, the adaptive learning algorithm adopts any modification in the actuator mechanism and hydraulic power system through updating the control knowledge. The results of implementing the build control knowledge for on-line operation of the ball-and-socket actuator shows a fully compliant actuator end-effector to the desired dynamic behaviour within the workspace.

Effect of magnet size on torque characteristic of three phase permanent magnet brushless DC motor

This paper deals with a design of high torque brushless DC motor (BLDC). This motor is designed in new arrangement of the stator teeth and operated as three phase motor. This motor is developed to produce high torque performance motor that could be used as in-wheel motor for agriculture applications such as tractors. The basic structure and principle of the motor is described briefly. The simulation Finite Element Method (FEM) technique is used in order to analyze the performance of the motor including flux flow path and flux distribution. Various sizes of magnet had been varied for torque and motor efficiency analysis by using simulation and analytical method, respectively. This found that the maximum output torque is achieved when both length and width of magnet is at largest size. The result also signifies that the increment of torque will not determine the increases in the motor efficiency as well. In the end, this paper could be used as a further research for the future.

Investigations on a Novel Inductive Concept Frequency Technique for the Grading of Oil Palm Fresh Fruit Bunches

From the Malaysian harvesters perspective, the determination of the ripeness of the oil palm (FFB) is a critical factor to maximize palm oil production. A preliminary study of a novel oil palm fruit sensor to detect the maturity of oil palm fruit bunches is presented. To optimize the functionality of the sensor, the frequency characteristics of air coils of various diameters are investigated to determine their inductance and resonant characteristics. Sixteen samples from two categories, namely ripe oil palm fruitlets and unripe oil palm fruitlets, are tested from 100 Hz up to 100 MHz frequency. The results showed the inductance and resonant characteristics of the air coil sensors display significant changes among the samples of each category. The investigations on the frequency characteristics of the sensor air coils are studied to observe the effect of variations in the coil diameter. The effect of coil diameter yields a significant 0.02643 MHz difference between unripe samples to air and 0.01084 MHz for ripe samples to air. The designed sensor exhibits significant potential in determining the maturity of oil palm fruits.