Qais A. Khasawneh

Sliding mode control of a simulated MEMS gyroscope.

The microelectromechanical systems (MEMS) are penetrating more and more into measurement and control problems because of their small size, low cost, and low power consumption. The vibrating gyroscope is one of those MEMS devices that will have a significant impact on the stability control systems in transportation industry. This paper studies the design and control of a vibrating gyroscope. The device has been constructed in a Pro-E environment and its model has been simulated in the finite-element domain in order to approximate its dynamic characteristics with a lumped model. A model reference adaptive feedback controller and the sliding mode controller have been considered to guarantee the stability of the device. It is shown that the sliding mode controller of the vibrating proof mass results in a better estimate of the unknown angular velocity than that of the model reference adaptive feedback controller.

Sliding mode control of a simulated MEMS gyroscope

The micro electro mechanical systems (MEMS) are penetrating more and more into measurement and control problems because of their small size, low cost, and low power consumption. The vibrating gyroscope is one of those MEMS devices that have significant impact on the stability control systems in transportation industry. This paper studies the design and control of a vibrating gyroscope. The device has been constructed in Pro-E environment and its model has been simulated in finite element domain in order to approximate its dynamic characteristics with a lumped model. A model reference adaptive feedback controller and the sliding mode controller have been considered to guarantee the stability of the device. It is shown that the sliding mode controller of the vibrating proof mass results in better estimate of the unknown angular velocity than that of the model reference adaptive feedback controller.

Application of SMC and NLFC Into a PRRR Robotic Arm

Industrial robotic arms are widely used nowadays. Accuracy and efficiency that fulfill user’s requirements are achieved through robust controller. This paper investigates dynamics modeling and control of a four DOF (PRRR) robot that is dedicated to perform a Pick-and-Place move of a certain product. The arm is undergoing manufacturing process. Forward and inverse kinematics solutions are introduced to solve the joint space trajectories associated with the desired End Effector (EE) Cartesian space path. The performance of two controllers under the presence of model uncertainties is inspected through a simulation study; Non-Linear Feedback Control (NLFC) and Sliding Mode Control (SMC) are designed and tested over the required joint space trajectories and Cartesian space path. Results showed that NLFC achieved better results than SMC in terms of RMSE when model uncertainties were absent. However, when model uncertainties were introduced, SMC performance was more robust than NLFC. Simulation results are very encouraging towards using the SMC over the actual robotic arm.© 2014 ASME

Scanning electron microscope fine tuning using four-bar piezoelectric actuated mechanism

Abstract Scanning Electron Microscopes are extensively used for accurate micro/nano images exploring. Several strategies have been proposed to fine tune those microscopes in the past few years. This work presents a new fine tuning strategy of a scanning electron microscope sample table using four bar piezoelectric actuated mechanisms. The introduced paper presents an algorithm to find all possible inverse kinematics solutions of the proposed mechanism. In addition, another algorithm is presented to search for the optimal inverse kinematic solution. Both algorithms are used simultaneously by means of a simulation study to fine tune a scanning electron microscope sample table through a pre-specified circular or linear path of motion. Results of the study shows that, proposed algorithms were able to minimize the power required to drive the piezoelectric actuated mechanism by a ratio of 97.5% for all simulated paths of motion when compared to general non-optimized solution.

Evolutionary low-cost visual shooting practice system

Conventional shooting practice systems are expensive, life threatening, and lack proper statistical evaluation of trainees performance. This paper presents the implementation and testing of a proposed evolutionary laser shooting practice system for early shooting practice stages. Presented system consists of a real gun replica equipped with lasers rather than live ammunition, a simple CCD camera, a shooting target, and a Compact Vision System (CVS) running National Instruments LabVIEW software. In order to detect con-centric rings of the shooting target an image processing algorithm is developed and employed by the CVS. In addition, the developed algorithm distinguishes locations of trainees laser shots relative to the center point of the shooting target. For each training session, the system delivers a detailed overall performance report including scores of shooter accuracy and precision. The system was tested at a 100 m long shooting range under different camera-to-target angles and various lighting conditions. Results proved robust performance with accurate and detailed shooting reports under all tested conditions. Presented system overcomes conventional shooting practice systems in terms of cost, safety, evaluation accuracy and portability.

Adaptive Control of a Simulated MEMS Gyroscope

Micro Electro Mechanical Systems (MEMS) are playing a significant role in industry because of their small size, small weight, and low power consumption. The vibrating gyroscope is one of those MEMS devices that will have significant impact in stability control of cars. This paper studies the design and control of a vibrating gyroscope. The device has been constructed in Pro-E environment and its model has been simulated in finite element domain in order to approximate its dynamic characteristics with a lumped model. An adaptive feedback control system that guarantees the stability of the device and consistent measurement of angular velocity has been constructed and simulated.Copyright