Rosmiwati Mohd-Mokhtar

Explicit kinematic model of the Mitsubishi RV-M1 robot arm

A complete kinematic model of the 5 DOF-Mitsubishi RV-M1 manipulator is presented in this paper. The forward kinematic model is based on the Modified Denavit-Hartenberg notation, and the inverse one is derived in closed form by fixing the orientation of the tool. A graphical interface is developed using MATHEMATICA software to illustrate the forward and inverse kinematics, allowing student or researcher to have hands-on of virtual graphical model that fully describe both the robots geometry and the robots motion in its workspace before to tackle any real task.

Position-based visual servoing through Cartesian path-planning for a grasping task

In this paper three visual servo schemes using the image-based and position-based techniques in a decoupled fashion are presented. These schemes are applied to grasping objects with orientation and position errors in an industrial grasping task. The servoing schemes are evaluated according to their rate of convergence to the desired grasping pose. The first two schemes rely on a constant image features extraction while the third one bypasses this reliance and uses a pose estimation of the camera at the initial and desired positions with a control law designed in 3D Cartesian space by Path Planning. It can be shown that the latter method ensures the shortest convergence time provided that a perfect pose estimation is performed.

Integral Super Twisting Sliding Mode Control (ISTSMC) Application in 1DOF Internal Mass Autonomous Underwater Glider (AUG)

This paper presents the design and implementation of the integral super twisting sliding mode control for the tracking control of a linearized model of longitudinal plane autonomous underwater glider. The performance of the proposed controller is evaluated in terms of chattering reduction in control input for the nominal system as well as the system in the presence of external disturbance. The controller is designed for the gliding path from 45° to 30° downward and upward. The performance of the proposed controller is compared with the quasi sliding mode control (boundary layer), integral sliding control, and super twisting sliding mode control. The simulation results have shown that the proposed controller is able to eliminate the undesired chattering.in control inputs.

Autonomous Agent for Universal Verification Methodology Testbench of Hard Memory Controller

Pre-silicon verification process is important in an application having integrated chip design cycle. It is considered one of the biggest bottle-neck in modern day design projects. This paper intends to describe a testbench architecture that will improve verification efficiency and productivity for a Hard Memory Controller’s Sideband verification from the perspective of the test writer. The testbench architecture described by Universal Verification Methodology is reused, adapted and improved to allow higher level of automation within the testbench. The implemented autonomous agent is analyzed and compared against the regular agent for its efficiency in terms of lines of code need to be written by the test writer. The result obtained shows that the autonomous agent implemented in the architecture reduces the test writer’s burden by at least 60 % and up to 78 %.

Statistical analysis of rain height over Malaysia

Rain height is one of the key parameters in rain attenuation prediction. However, few studies on it had been carried out due to unavailability of data especially over tropics. Presented here is the result of eleven years zero degree isotherm height for eight locations over Malaysia. The studies had been carried out over two main seasons in the country (Northeast and Southwest Monsoon). The result shows that rain height is grossly under estimated by ITU-R P. 839-3.

Near-Minimum Time Visual Servoing of an Underactuated Robotic Manipulator

Rate of convergence to the desired pose to grasp an object using visual information may be important in some applications, such as a pick and place routine in assembly where the time between two stops of the conveyor is very short. The visually guided robot is required to move fast if vision is to bring the sought benefits to industrial setups. In this paper, the three most famous techniques to visual servoing, mainly the image-based, position-based and hybrid visual servoing are evaluated in terms of their speed of convergence to the grasping pose in a pick and place task of a momentarily motionless target. An alternative open-loop near-minimum time approach is also presented and tested on a 5DOF under-actuated robotic arm. The performance is compared and result shows significant reduction for its time of convergence, to the aforementioned techniques.

Signal sensitivity to supply noise on high-speed I/O

Power Distribution Network (PDN) is optimized based on conventional AC and DC noise target specification. Large supply noise occurs due to increase in speed and number of I/O running simultaneously. In this paper, an alternate means to quantify supply noise to signal performance is discussed. Discussion focuses on signal performance impact caused by supply noise with different frequency content. Simulation is carried out using transistor model and findings are then correlated through lab measurements. Using USB I/O as a test case, findings conclude that the USB transmitter performance is less sensitive to supply noise at circuit operating frequency (480 MHz) and its harmonic. Hence, excessive AC noise at its less sensitive region will not cause signal eye diagram to fail.