Mohd. Marufuzzaman

Hardware prototyping of an intelligent current dq PI controller for FOC PMSM drive

Field Oriented Control (FOC) Permanent Magnet Synchronous Motor (PMSM) is a commutator less servo drive which provides high controllability, greater efficiency, superior torque to inertia ratio and high power density. However, the performance of FOC-PMSM depends on the driver circuits, which requires expensive computing elements. Besides, an intelligent current regulator is desired for a highly precise driver. This research proposed a hardwire prototype of current dq PI controller as a part of real-time hardwired motion intelligent driver which was previously solved using software and firmware dependent modules. The outcome will be a single chip current dq PI controller for FOC-PMSM drive.

Effectiveness of Wavelet Denoising on Electroencephalogram Signals

Analyzing Electroencephalogram (EEG) signal is a challenge due to the various artifacts used by Electromyogram, eye blink and Electrooculogram. The present de-noising techniques that are based on the frequency selective filtering suffers from a substantial loss of the EEG data. Noise removal using wavelet has the characteristic of preserving signal uniqueness even if noise is going to be minimized. To remove noise from EEG signal, this research employed discrete wavelet transform. Root mean square difference has been used to find the usefulness of the noise elimination. In this research, four different discrete wavelet functions have been used to remove noise from the Electroencephalogram signal gotten from two different types of patients (healthy and epileptic) to show the effectiveness of DWT on EEG noise removal. The result shows that the WF orthogonal meyer is the best one for noise elimination from the EEG signal of epileptic subjects and the WF Daubechies 8 (db8) is the best one for noise elimination from the EEG signal on healthy subjects.

FPGA implementation of an intelligent current dq PI controller for FOC PMSM drive

Field Oriented Control (FOC) Permanent Magnet Synchronous Motor (PMSM) is mostly used as it provides superior torque to inertia ratio, high controllability and greater power density amongst all the servo drives. However, expensive computing elements are required for the driver circuits which are the key factor of determining the overall performance of FOC-PMSM drives. In addition, an exact direct and quadrature (dq) current is desired for a highly precise driver which can be ensured by an intelligent PI controller. This research proposes an FPGA implementation of current dq PI controller as a part of real-time hardware motion intelligent driver. The outcome will be a single chip current dq PI controller which was previously solved using software and firmware dependent modules. This hardware implementation system can get a high-speed level as well as an exciting precision. Thus it will be a key element for designing a fully automated real time hardware implementation of FOC-PMSM drive.

A Time Series Based Sequence Prediction Algorithm to Detect Activities of Daily Living in Smart Home

OBJECTIVES The goal of smart homes is to create an intelligent environment adapting the inhabitants need and assisting the person who needs special care and safety in their daily life. This can be reached by collecting the ADL (activities of daily living) data and further analysis within existing computing elements. In this research, a very recent algorithm named sequence prediction via enhanced episode discovery (SPEED) is modified and in order to improve accuracy time component is included. METHODS The modified SPEED or M-SPEED is a sequence prediction algorithm, which modified the previous SPEED algorithm by using time duration of appliances ON-OFF states to decide the next state. M-SPEED discovered periodic episodes of inhabitant behavior, trained it with learned episodes, and made decisions based on the obtained knowledge. RESULTS The results showed that M-SPEED achieves 96.8% prediction accuracy, which is better than other time prediction algorithms like PUBS, ALZ with temporal rules and the previous SPEED. CONCLUSIONS Since human behavior shows natural temporal patterns, duration times can be used to predict future events more accurately. This inhabitant activity prediction system will certainly improve the smart homes by ensuring safety and better care for elderly and handicapped people.

Differential ring oscillator based voltage control oscillator for readerless RFID transponder

Designing a compact, power efficient voltage controlled oscillator (VCO) for high frequency phase lock loop (PLL) in modern wireless communication system is decisively a challenging task. Inappropriately designed VCOs for battery-powered radio frequency identification (RFID) transponder cause huge degradation of overall system. The proposed work presents a low power 2.45 GHz VCO developed for active readerless transponder compatible with IEEE 802.11b protocol. A 3-stage, single delay path, differential ring oscillator based architecture has been adopted for the ease of integration and implementation of the circuit in small die area. 0.18μm CMOS process is used for designing the proposed VCO. Simulated results showed that the proposed VCO would work in the tuning range of 2.4GHz-2.5GHz with 1.8V supply. Thus, the proposed VCO will be a key component for readerless RFID transponder.

The evolution of digital to analog converter

In the past few decades there have been many developments in the design methodology of DAC to meet the stringent performance requirements of their endless applications. These design strategies can be categorized into several classifications. Based on the literature review the history of the evolution, advantages and limitation of each method can be summarized. Such survey is of high essence to meet performance specifications while doing reasonable tradeoff between the various design parameters. To this perspective, in this paper, first we present a brief summary of different kinds of widely used DACs, their advantages, disadvantages. Lastly and most importantly a survey on various design strategies developed to tackle the limitations of different kinds of DACs, while achieving optimum architecture has been presented.

A study on low power phase frequency detectors for delay locked loop

Delay Locked Loops (DLL) adapted in various applications due to its low power characteristics. Aggressive power demand in sensors, medical devices and new communications applications with embedded DLL has affected by Phase Frequency Detector (PFD) design techniques. This paper presents a review of various PFD in DLL design based on their main parameters including dynamic logic PFD topologies, PFD important parameters and issues total power consumption as well as their design trade-offs. This review paper gives a guideline to the future researchers for designing high speed and low power PFD.

Design and Implementation of a Low Supply Voltage Voltage Type Sense Amplifier with Low Current Consumption for RFID Transponder

Current or voltage-type sense amplifier (SA) is the key element for sensing process of RFID transponder EEP-ROM. The performance of the EEPROM is influenced by the SA features like memory access time, power dissipation and the reliability. However, larger current or power dissipation put limitations on using current type SA with respect to voltage type SA. A low voltage SA with lower current consumption is presented in this research work, which is compatible with the low power applications like RFID transponder EEPROM. In this research, 0.18μm process is employed to design the low voltage SA with lower power consumption. The simulated results of the output showed that voltage type SA is able to operate under a low power supply voltage (VDD). In addition, only 32 μA current is dissipated by the modified voltage type SA during read period. Moreover, the proposed voltage type SA provides better reliability than the circuits presented in other research papers.