Asiya M. Al-Busaidi

Development of an educational environment for online control of a biped robot using MATLAB and Arduino

This paper describes the development of innovative low-cost educational platform to study and control a biped robot in real-time using MATLAB and Arduino board. MATLAB was used as a control and visualization environment, while the Arduino board was utilized as a final controller for the servo motors as well as a Data Acquisition Card (DAC). However, it is important to recognize that there is much more knowledge to learn to control a robot, such as hardware (sensors, actuators) knowledge, software knowledge and control theory. But, it is important to emphasize that this paper is merely focused on the hardware and software development which can be utilized to accomplish many tasks like controlling the walking motion. Here the platform set up and the algorithm adopted in controlling the servos as well as reading from the sensors are described such that any student can reconstruct and start using it to understand his/her subject.

Wearable wireless medical sensors toward standards, safety and intelligence: a review

Using miniature wearable devices, it is possible to follow the health of individuals from outside the hospital in a convenient and easy way that does not restrict their movements or their daily activities. The wearable biomedical sensors or the Wireless Body Area Network (WBAN) systems is about to become an important tool to match the express way of life nowadays. This paper reviews the technological developments in wireless sensor nodes for biomedical applications during the last decade. The review covers the electronics hardware design, challenges, safety and ending by the standards required to implement those systems. The designer of the wearable medical sensor should be aware of the standards and the safety issues at the acquisition and storage level, wireless transmission protocol level, powering level, security and privacy level, and overall safety level. Finally, this paper suggests some of the recent technologies that can be used to enhance the future WBAN systems.

Optimum Mandrel Configuration for Efficient Down-Hole Tube Expansion

In the last decade, traditional tube expansion process has found an innovative application in oil and gas wells drilling and remediation. The ultimate goal is to replace the conventional telescopic wells to monodiameter wells with minimum cost, which is still a distant reality. Further to this, large diameters are needed at terminal depths for enhanced production from a single well while keeping the power required for expansion and related costs to a minimum. Progress has been made to realize slim wells by driving a rigid mandrel of a suitable diameter through the tube either mechanically or hydraulically to attain a desirable expansion ratio. This paper presents a finite element model, which predicts the drawing force for expansion, the stress field in expanded and pre-/postexpanded zones, and the energy required for expansion. Through minimization of energy required for expansion, an optimum mandrel configuration, i.e., shape, size, and angle, was obtained, which can be used to achieve larger in situ expansion. It is found that mandrel with elliptical, hemispherical, and curved conical shapes has minimum resistance during expansion as compared to the widely used circular cross section mandrel with a cone angle of 10 deg. However, further manipulation of shape parameters of the circular cross section mandrel yielded an improved efficiency. The drawing force required for expansion reduces by 7–10% having minimum dissipated energy during expansion. It is also found that these mandrels yield less reduction in tube thickness after expansion, which results in higher postexpansion collapse strength. In addition, rotating a mandrel further reduces the energy required for expansion by another 7%.

Real-time DWT-based compression for wearable Electrocardiogram monitoring system

Compression of Electrocardiogram signal is important for digital Holters recording, signal archiving, transmission over communication channels and Telemedicine. This paper introduces an effective real-time compression scheme to overcome the limitation of payload size of the transmission channel. This scheme utilizes the Discrete Wavelet Transform (DWT), Bit-Field Preserving (BFP) and Running Length Encoding (RLE) methods which showed efficient compression results. The scheme dynamically checks if the compressed packets fit into the available payload. If not, the original signal will be divided into blocks and each block will be re-compressed again. The dynamic scheme was tested on large and small number of samples. The results show that a small block of 64, 128 or 256 samples will not affect the compression performance and no distortion occurred on the reconstructed signal.

Optimum mandrel configuration for efficient down-hole tube expansion

In the last decade, traditional tube expansion process has found an innovative application in oil and gas well drilling and remediation. The ultimate goal is to replace the conventional telescopic wells to mono-diameter wells with minimum cost, which is still a distant reality. Further to this, large diameters are needed at terminal depths for enhanced production from a single well while keeping the power required for expansion and related costs to a minimum. Progress has been made to realize slim wells by driving a rigid mandrel of a suitable diameter through the tube either mechanically or hydraulically to attain a desirable expansion ratio. This paper presents a finite element model which predicts the drawing force for expansion, the stress field in expanded and pre/post expanded zones, and the energy required for expansion. Through minimization of energy required for expansion, an optimum mandrel configuration i.e. shape, size and angle was obtained which can be used to achieve larger in-situ expansion. It is found that mandrel with elliptical, hemispherical and curved conical shapes have minimum resistance during expansion as compared to the widely used circular cross section mandrel with a cone angle of 10°. However, further manipulation of shape parameters of the circular cross section mandrel revealed an improved efficiency. The drawing force required for expansion reduces by 7% to 10% having minimum dissipated energy during expansion. It is also found that these cones yield less reduction in tube thickness after expansion, which results in higher post-expansion collapse strength. In addition, rotating a mandrel further reduces the energy required for expansion by 7%.Copyright

Wavelet-based Encoding Scheme for Controlling Size of Compressed ECG Segments in Telecardiology Systems

One of the major issues in time-critical medical applications using wireless technology is the size of the payload packet, which is generally designed to be very small to improve the transmission process. Using small packets to transmit continuous ECG data is still costly. Thus, data compression is commonly used to reduce the huge amount of ECG data transmitted through telecardiology devices. In this paper, a new ECG compression scheme is introduced to ensure that the compressed ECG segments fit into the available limited payload packets, while maintaining a fixed CR to preserve the diagnostic information. The scheme automatically divides the ECG block into segments, while maintaining other compression parameters fixed. This scheme adopts discrete wavelet transform (DWT) method to decompose the ECG data, bit-field preserving (BFP) method to preserve the quality of the DWT coefficients, and a modified running-length encoding (RLE) scheme to encode the coefficients. The proposed dynamic compression scheme showed promising results with a percentage packet reduction (PR) of about 85.39% at low percentage root-mean square difference (PRD) values, less than 1%. ECG records from MIT-BIH Arrhythmia Database were used to test the proposed method. The simulation results showed promising performance that satisfies the needs of portable telecardiology systems, like the limited payload size and low power consumption.

Packet-size-Controlled ECG Compression Algorithm based on Discrete Wavelet Transform and Running Length Encoding

This paper presents a development of new size-controlled compression algorithm for Electrocardiogram signal (ECG). Discrete Wavelet Transform (DWT) method, Bit-Field Preserving (BFP) and Running Length Encoding (RLE) are selected as compression tools in this work. Even though DWT-BFP-RLE is a lossy compression method, it has shown a potential in preserving the critical (diagnostic) part of the signal. Knowing that the size of transmitted packets of the battery-powered mobile telecardiology systems is limited within few bytes, the current algorithm is aiming to ensure that the compressed packets fit into the limited payload size. A parametric study of different mother wavelets and decomposition levels of DWT is presented with an emphasize on compression ratio (CR), percentage mean-square difference (PRD) and quality score (QS). The mother wavelet giving the best CR and QS results is then adopted to perform the dynamic compression algorithm on ECG records from MIT-BIH arrhythmia database.

Control of biped robot joints' angles using coordinated matsuoka oscillators

Neural Oscillators are network of neurons that produce smooth oscillatory/rhythmic pattern. In this paper, a simple network of Matsuoka oscillators is used to generate the bipedal locomotion by coordinating the joint angle using a new method of coordination proposed by Huang. This method makes the control of the joint angle easier as they are related with each other in a sequential manner. Also, this method prevents error accumulation with time. The results show that the robot produced a smooth walking motion.