Transmitter Unit Research Articles

Arduino UNO Based Wheelchair Control using Bluetooth and Android Mobile

The main goal of this project is to design and construct a low-cost wheelchair control system that uses an Android phone. Patients with diverse physical limitations have relied on wheelchairs to assist them with movement and to meet their day-to-day prerequisites. However, in other circumstances, the mobility of a wheelchair is dependent on another person. It includes people who are unable to lift their arms or push the wheels forward, such as paraplegics, quadriplegics, stroke patients, the elderly, and others. Joystick-oriented wheelchairs, which are supposed to be a solution for these people, might cause a variety of issues since they demand fundamental shoulder mobility. For the categories described above of patients, this is not always practicable. Furthermore, because it is wireless and can be worn on either hand, this solution does not have the positioning restrictions that a joystick wheelchair could have, allowing the user to sit in their preferred posture for the least amount of pain. The goal of this initiative is to enable autonomous mobility for people with disabilities. Thus, this research study provides a Bluetooth-based wheelchair prototype that maybe operated by an Android smartphone application. A transmitter and a receiver that can communicate wirelessly makeup the framework. The 433 Mhz RF Transmitter and Receiver Unit was utilized for wireless transmission since it delivers data through an antenna at speeds ranging from 1Kbps to 10Kbps and has a range of up to 100 metres, The wheelchair's receiver unit receives signals from the transmitter unit through an Arduino Uno micro-controller, which causes the wheels to turn in the desired direction. Motor drivers that convert electricity as needed by the wheels makeupmakeup the reception unit. This technology offers an alternative to commercial wheelchairs since it is more effective, less expensive, and simpler to control.

Internet of Things-Based Automated Shopping Cart Incorporated With Virtual Instrumentation Using LabVIEW for Control Applications

Shopping mall or a super market is a first choice for buying all necessary products and that is why it attracts more number of customers than the retail shop. But the problem is it creates too many hurdles for customer and owner to maintain the order and keep sync with the time at billing counter. The normal billing and shopping system lacks the time saving approach also it doesn't have proper security arrangements to avoid theft and duplication. To overcome this issue, we developed a smart way for shopping using LabVIEW incorporated with internet of things (IOT). Each and every product contains RFID tag. The smart trolley will consist of a RFID reader, transmitter and ZigBee unit. Along with this, the cart is equipped with the child monitor unit. The whole system is controlled by utilizing the controller developed using LabVIEW. The ZigBee module attached in the cart is responsible for sending the bill to the main billing system and IOT feature is also enabled so that shopping-bill of each customer is mailed to their respective mail-id through esp8266 Wi-Fi module.

Wireless Data Logger Instrument for Indoor Acoustic Quality Measurement Based on Noise Background, Sound Distribution and Reverberation Time

A wireless data logger system measuring indoor acoustic quality was developed using a NodeMCU ESP8266 and microphone sensor KY-037. The acoustic quality is based on parameters of sound pressure level and reverberation time. The system consists of a transmitter unit and a receiver unit. The transmitter unit is equipped with a Microphone KY-037 sensor as a sound detector and NodeMCU ESP8266 as a microcontroller and serial communication with the database. The transmitter unit of this measuring instrument is set at predetermined position points in a room. The results of testing the sound pressure level have an error percentage of 2.09% compared to the Digital Sound Level Meter GM1356 tool. Comprehensive testing of the tool has sent and processed sensor measurement data wirelessly into the database. The processed data is displayed through a GUI web server in the form of a background noise average, an average of the reverberation time value, and a graph of the sound pressure level in the room.

Versatile and Concurrent FPGA-Based Architecture for Practical Quantum Communication Systems

This article presents a hardware and software architecture, which can be used in those systems that implement practical quantum key distribution (QKD) and quantum random-number generation (QRNG) schemes. This architecture fully exploits the capability of a System on a Chip (SoC), which comprehends both a field-programmable gate array (FPGA) and a dual-core CPU unit. By assigning the time-related tasks to the FPGA and the management to the CPU, we built a flexible system with optimized resource sharing on a commercial off-the-shelf (COTS) evaluation board, which includes an SoC. Furthermore, by changing the dataflow direction, the versatile system architecture can be exploited as a QKD transmitter, QKD receiver, and QRNG control-acquiring unit. Finally, we exploited the dual-core functionality and realized a concurrent stream device to implement a practical QKD transmitter, where one core continuously receives fresh data at a sustained rate from an external QRNG source, while the other operates with the FPGA to drive the qubit transmission to the QKD receiver. The system was successfully tested on a long-term run proving its stability and security. This demonstration paves the way toward a more secure QKD implementation, with fully unconditional security as the QKD states are entirely generated by a true random process and not by deterministic expansion algorithms. Eventually, this enables the realization of a standalone quantum transmitter, including both the random numbers and the qubit generation.

Steady-State Multiple Parameters Estimation of the Inductive Power Transfer System

In this paper, we proposed a novel steady-state multiple parameters estimation method of the two-coil inductive power transfer (IPT) system based on the measurement of the primary-side voltage and current fundamentals. The method is used to estimate key parameters, such as mutual inductance and equivalent load resistance, as well as receiver self-inductance and compensation capacitance values, and the total parasitic resistance of the secondary side. The method also allows the identification of the secondary-side resonant frequency. The parameters estimation procedure involves three operating modes of the IPT system: 1) open-circuit of the secondary side, 2) short-circuit of the secondary side, and 3) load connection. Each of these modes allows the identification of different parameters. To make the system operate in predefined modes, two switches are added to the receiver circuit. These switches are controlled from the secondary side, while the parameters estimation process, including load voltage and/or current control, is fully conducted on the primary side. The experimental tests on the prototype have validated the proposed method and demonstrated its effectiveness. The method can be applied to a new generation of high-performance wireless battery charging systems, where the single transmitter unit can be used to charge the battery pack in different devices.

Global optimisation approach for designing high-efficiency piezoelectric beam-based energy harvesting devices

The paper proposes a novel methodology for developing high-power energy harvesting gravity-based devices using an array of piezoelectric beams for wind energy applications. The methodology incorporates a global multidimensional constrained optimisation algorithm, which accounts for the physical size of the device, the physical, geometrical and electrical properties of the piezoelectric beams, and the power management circuit to increase the device’s efficiency. As the beams are plucked sequentially, they vibrate out-of-phase, which consequently leads to charge cancellation issues. The paper proposes and incorporates an electrical circuit design to avoid such problems, being able to further increase the efficiency of the device by 35% when compared against the output from the standard energy harvesting (SEH) circuit with independent rectifiers. The proposed optimisation methodology is applied to the devices utilising flexible polyvinylidene fluoride beams. The developed dynamic numerical model of the beams’ vibration is validated using the experimental results and the results of a Finite Element Analysis. To study the electro-mechanical coupling of the beams, an electric circuit and the power management circuit are created and modelled in Matlab/Simulink software. The optimised device delivers 6 to 17 times higher energy output compared to the unoptimised device. The performance of this device was also compared to that of the device with much stiffer LiNbO3 beams (Clementi et al., 2021, [1]) to demonstrate the direct applicability of such devices to power sensors and transmitter units for structural monitoring of wind turbine blades. It has been demonstrated that the LiNbO3-beam device yields an energy output with one order of magnitude higher. The applied optimisation methodology enabled a 0.057 × 0.017 × 2 m3 dimension device to produce a power output in the range from 0.5 to 1 W depending on the blades’ speed, resulting in 1.06 mW/cm3 power density of the device.

Circularly Polarized FP Resonator Antenna With 360° Beam-Steering

A high gain circularly polarized Fabry–Perot (FP) resonator antenna with 360° beam steering property is presented in this communication. A linear to circular polarization conversion metasurface (PCM) based on a receiver–transmitter unit cell is designed to act as the partially reflecting surface (PRS) of the FP resonator antenna. The transmission phase of the unit cell can be tuned by rotating the radiator and transmission phase shift of the unit cell equal to the rotation angle of the radiator, indicating that the transmission phase varies over a range of 360°. Then, by manipulating the transmission phase of unit cells on the metasurface (MS), the antenna can realize 360° beam steering with an angle tilted range of 0°–75°. To further enhance the antenna performance, the compensatory transmission phase is added to each unit cell on the MS, which can make the antenna obtain higher gain while realizing tilted beam. The measured results of the fabricated antennas imply the feasibility of this design. The proposed MS provides a novel method to realize beam steering of the circularly polarized FP resonator antenna.

A 28Gbps high-speed SERDES transmitter

A high-speed (28Gbps) interface transmitter design based on a Source-Series Terminated drive structure is introduced. The architecture and principle of the entire TX are described in detail; the clock duty cycle calibration (DCC) circuit with digital-analog hybrid control is used to effectively reduce the DCD; and a transmitter unit based on SST structure impedance tuning and weighted balance decoupling is improved The structure greatly reduces the complexity of logic control. The transmitter circuit can be used for FPGAs that require a transmission rate of 1 Gbps~28 Gbps. The design is made with SMIC14 nm FinFET technology. The sample test results show that when the output rate is 28 Gbps, the transmitter's indicators meet the PCIE 4.0 protocol standard.

Design of Powering Wireless Medical Sensor Based on Spiral-Spider Coils

Biomedical sensors help patients monitor their health conditions and receive assistance anywhere and at any time. However, the limited battery capacity of medical devices limits their functionality. One advantageous method to tackle this limited-capacity issue is to employ the wireless power transfer (WPT) technique. In this paper, a WPT technique using a magnetic resonance coupling (MRC-WPT)-based wireless heart rate (WHR) monitoring system—which continuously records the heart rate of patients—has been designed, and its efficiency is confirmed through real-time implementation. The MRC-WPT involves three main units: the transmitter, receiver, and observing units. In this research, a new design of spiral-spider coil was designed and implemented for transmitter and receiver units, respectively, to supply the measurement unit, which includes a heart rate sensor, microcontroller, and wireless protocol (nRF24L01) with the operating voltage. The experimental results found that an adequate voltage of 5 V was achieved by the power component to operate the measurement unit at a 20 cm air gap between the receiver and transmitter coils. Further, the measurement accuracy of the WHR was 99.65% comparative to the benchmark (BM) instrument. Moreover, the measurements of the WHR were validated based on statistical analyses. The results of this study are superior to those of leading works in terms of measurement accuracy, power transfer, and Transfer efficiency.

Simultaneous Power Feedback and Maximum Efficiency Point Tracking for Miniaturized RF Wireless Power Transfer Systems.

Near-field interfaces with miniaturized coil systems and low output power levels, such as applied in biomedical sensor systems, can suffer from severe efficiency degradation due to dynamic impedance mismatches, reducing battery life of the power transmitter unit and requiring to increase the level of electromagnetic emission. Moreover, the stability of weakly-coupled power transfer systems is generally limited by transient changes in coil alignment and load power consumption. Hence, a central research question in the domain of wireless power transfer is how to realize an adaptive impedance matching system under the constraints of a simultaneous power feedback to increase the system’s efficiency and stability, while maintaining circuit characteristics such as small size, low power consumption and fast reaction times. This paper presents a novel approach based on a two-stage control loop implemented in the primary-side reader unit, which uses a digital PI controller to maintain the rectifier output voltage for power feedback and an on-top perturb-and-observe controller configuring the setpoint of the voltage controller to maximize efficiency. The paper mathematically analyzes the AC and DC transfer characteristics of a resonant inductive link to design the reactive AC matching network, the digital voltage controller and ultimately the DC-domain impedance matching algorithm. It was found that static reactive L networks result in suitable efficiency levels for coils with sufficiently high quality factor even without adaptive tuning of operational frequency or reactive components. Furthermore, the regulated output voltage of the rectifier is a direct measure of the DC load impedance when using a regular DC/DC converter to supply the load circuits, so that this quantity can be tuned to maximize efficiency. A prototype implementation demonstrates the algorithms in a 40.68 MHz inductive link with load power levels from 10 to 100 mW and tuning time constants of 300 ms, while allowing for a simplified receiver with a footprint smaller than 200 mm2 and a self-consumption below 1 mW. Hence, the presented concepts enable adaptive impedance matching with favorable characteristics for low-energy sensor systems, i.e., minimized footprint, power level and reaction time.

An Approach to Design a Wireless Air Flow Transmitter Using Flex Sensor

In process industries, air flow rate measurement and transmission are usually performed by various passive conventional sensors. Here, air flow rate for moderate flow applications is sensed by resistive type flexible bend sensor having the characteristics of light weight, tiny size, cost-effective, fine linearity and also good repeatability. The flexible resistive type bends sensor which acts as a cantilever beam derives the linear relationship between air flow rate and the change in resistance of the sensor in the form of an electrical signal. For transmission purposes, the generated electrical signal passes through the electrical communication system which is not permeable in hazardous and inflammable areas of the process industry. Henceforth, for the data transmission purpose, Internet of Things (IoT) is being introduced in industries for avoiding explosions due to electric spark and also the real-time data is transmitted throughout the globe with the help of internet. The proposed air flow transmitter has been theoretically analyzed in this paper and the relationship of air flow rate with a transmitted voltage signal has been derived. The experiment has been performed on the fabricated prototype air flow measuring unit. The experimental results are presented in the paper which is matched with the theoretical one. The proposed IoT based air flow transmitter unit shows linear characteristic with good repeatability. The higher value of air or any clean fluid flow rate can be measured by this prototype flow transmitter by only changing the dimensions of the cantilever type bend sensor.

Development of a YAMUGAG-20 Wireless Exploder for Safe Disposal of Military and Civil Explosives

YAMUGAG-20 Exploder is a Radio Frequency (RF)-based wireless exploder system designed and constructed specially for the Nigerian Air Force (NAF) to overcome the challenges associated with the existing wired exploders used for the disposal of unserviceable ordnances. The Exploder system has three main parts namely, the master transmitter unit, the master receiver/slave transmitter unit, and the slave receiver unit. Each of these units is made up of transceiver module, microcomputer and power source. The microcomputers were programmed using C and C++ programming language of the Integrated Development Environment (IDE) software. The exploder is portable and easy to operate. For a typical demolition exercise, the operation of the exploder is such that signals are relayed from the master transmitter unit to the master receiver/slave transmitter unit onto the slave receiver unit to initiate an electric detonator leading to the detonation of the unserviceable ordnances. Functionality, range, power consumption, and system reliability tests were conducted on the exploder to establish its performance and efficiency. The results obtained from the tests indicated that the exploder transmitting at a frequency of 2.4GHz performed satisfactorily up to a range of 1000 meters. Therefore, the exploder has the potential of not only meeting the demolition demands of the NAF but can also be applied for other nonmilitary purposes like mining and related activities.

Development of a YAMUGAG-20 Wireless Exploder for Safe Disposal of Military and Civil Explosives

YAMUGAG-20 Exploder is a Radio Frequency (RF)-based wireless exploder system designed and constructed specially for the Nigerian Air Force (NAF) to overcome the challenges associated with the existing wired exploders used for the disposal of unserviceable ordnances. The Exploder system has three main parts namely, the master transmitter unit, the master receiver/slave transmitter unit, and the slave receiver unit. Each of these units is made up of transceiver module, microcomputer and power source. The microcomputers were programmed using C and C++ programming language of the Integrated Development Environment (IDE) software. The exploder is portable and easy to operate. For a typical demolition exercise, the operation of the exploder is such that signals are relayed from the master transmitter unit to the master receiver/slave transmitter unit onto the slave receiver unit to initiate an electric detonator leading to the detonation of the unserviceable ordnances. Functionality, range, power consumption, and system reliability tests were conducted on the exploder to establish its performance and efficiency. The results obtained from the tests indicated that the exploder transmitting at a frequency of 2.4GHz performed satisfactorily up to a range of 1000 meters. Therefore, the exploder has the potential of not only meeting the demolition demands of the NAF but can also be applied for other nonmilitary purposes like mining and related activities.

Patch Array Antenna for Health Care and Monitoring System

Health Care is the biggest challenge in today's world. There is a huge gap between the population and the number of health care professionals. One of the possible solutions can be a remote health monitoring system which is better known as telehealth. This paper deals with the design of antenna which will serve as the transmitter unit of the health care monitoring system which is fitted with the patient’s body. The paper describes a Swastik shaped antenna operating at a frequency of 3.5 GHz. The designed antenna shows efficiency of 93.8% with a simulated gain of 9.08 dB and a reflection coefficient of -23.50 dB. In this work, the two sides of Swastik (right and left part) are designed separately and then both were merged to have a complete design. The results show a considerable increase in the gain of the overall antenna as compared to the right side or left side of the swastika design.

A 15-W Triple-Mode Wireless Power Transmitting Unit With High System Efficiency Using Integrated Power Amplifier and DC–DC Converter

In this article, we present an integrated triple-mode wireless power transmitter unit (TWPTU) circuit supporting all three alliance for wireless power (A4WP), wireless power consortium (WPC), and power matters alliance (PMA) standards, simultaneously, for high-efficiency battery charging application. The triple-mode power amplifier (PA) utilizes the adaptive gate splitting technique and free-wheeling control to achieve high efficiency in triple modes. The programmable supply voltage from two high-efficiency dc–dc converters supplies the PA. The output power of the PA is measured by the proposed high accuracy current sensor and controlled through different communication protocols depending on their operating standards. The WPC/PMA modes are based on the amplitude-shifting-key and frequency-shifting-key modulations for the communication between the transmitter and the receiver, while in the A4WP mode, to control the output power of the PA, the bluetooth-low-energy (BLE) unit adjusts the supply voltage through the provided step-up dc–dc converter. A step-down dc–dc converter with pulse-skipping modulation reduces the power consumption of the TWPTU during charge waiting time. The demodulator for in-band communication of WPC/PMA and interintegrated circuit for BLE communication of A4WP is fully implemented. This chip is fabricated using a 180-nm bipolar-CMOS-DMOS (BCD) process with laterally diffused <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> options and has a die size of 5 × 3.5 mm. The proposed architecture achieves the output power level of 25.8 W. The measurement results show the maximum system efficiencies of the TWPTU in WPC/PMA and A4WP modes are 88.5% and 84.3%, respectively.

A Wearable CMOS Impedance to Frequency Sensing System for Non-Invasive Impedance Measurements.

In this paper, we demonstrate a novel non-invasive, wearable impedance sensor. The impedance sensor, using an impedance to frequency measurement, with two modes of resistance and capacitance measurement is implemented in CMOS 130nm technology. The sensor consisting of current and voltage comparators for different mode of measurement, has a low power consumption of 30 μW per channel. The sensor is demonstrated in two applications, thoracic impedance and hand gesture recognition. Thoracic impedance is based on impedance modulation through fluid accumulation. Hand gestures are detected through tissue impedance sensing. The full thoracic impedance sensing system is smaller than a credit card, low cost, and consumes 3mW which includes the sensor, transmitter, and power control unit. Data received by this sensor can be easily transferred for further processing and, eventually, detection of heart failure. The electrodes were implemented using conductive paint, and the system was validated using passive loads to represent human tissue models and test subjects. The hand gesture system operates on 600 μW with the maximum number of electrodes, and uses adhesive copper with electrical paint as electrodes.

An RSSI-Based Localization, Path Planning and Computer Vision-Based Decision Making Robotic System

A robotic navigation system operates flawlessly under an adequate GPS signal range, whereas indoor navigation systems use the simultaneous localization and mapping system or other vision-based localization systems. The sensor used in indoor navigation systems is not suitable for low power and small scale robotic systems. The wireless area network transmitting devices have fixed transmission power, and the receivers get the different values of signal strength based on their surrounding environments. In the proposed method, the received signal strength index (RSSI) values of three fixed transmitter units are measured every 1.6 m in mesh format and analyzed by the classifiers, and robot position can be mapped in the indoor area. After navigation, the robot analyzes objects and detects and recognize human faces with the help of object recognition and facial recognition-based classification methods respectively. This robot detects the intruder with the current position in an indoor environment.

Wireless Gesture Control Wheelchair

Wheelchairs have been used by patients who suffer from various physical disabilities to help them with locomotion and cater their day to day needs with ease. But there are some cases where the movement of a wheelchair is dependent on another individual as is the case with patients who lack the required arm strength and movement to properly push the wheels forward such as quadriplegics, paraplegics, stroke patients, elders etc. Joystick oriented wheelchairs, thought to be a solution to those kinds of patients, can pose different problems as it requires basic shoulder movement. It is not always possible for the aforementioned types of patients. In addition, our solution doesn’t have the positional constraints that a joystick wheelchair might have as it is wireless and can be worn on either hand which allows the patient to sit in their preferred position for minimum discomfort. This project is an attempt to help the disabled move around independently. Thus, in this research work, we present a prototype of a wireless gesture-based wheelchair which can be controlled via hand gestures. The framework consists of a transmitter and a receiver that communicate with each other wirelessly. For wireless transmission, 433Mhz RF Transmitter and Receiver Unit has been used as it transmits data through an antenna at the speed of 1Kbps – 10Kbps and the range can be adjusted as required. The transmitter unit consists of an Arduino LilyPad microcontroller and an accelerometer that has been attached to a hand glove. The accelerometer sensor has been used to register the position of the hand while creating a gesture. This glove is supposed to be worn by the patient allowing them to move their hand conveniently, sending signals to the receiver unit connected to the wheelchair leading to the movement of the wheels in the desired direction. The receiver unit consist of motor drivers that convert the voltage as needed by the wheels. This paper presents an alternative to the commercial wheelchairs as it is cost effective, easy to control and efficient. The working and assembly of the system has been explained in the paper.

VLC4WoT : Visible Light Communication for Web of Things

Recently, new devices have been developed for the Internet of Things concept. The devices commonly use RF (Radio Frequency) based wireless communication. With the increase in the number of devices, the space allocated for the radio frequency band in wireless communication fills rapidly. Visible Light Communication (VLC) is an alternative, secure and economical communication technology that uses light instead of radio frequencies. While Web of Things (WoT) is the adaptation of the experience and knowledge acquired from the web into the internet of things ecosystems. By combining these two technologies, the development of the Visible Light Communication for Web of Things (VLC4WoT) system, which can use VLC and WoT technologies, has been our motivation. In our study, microcontroller control circuit was created for VLC4WoT system. Control of the circuits over the internet was performed. VLC based receiver and transmitter units have been developed for wireless communication. Web based interface was created for control. The test apparatus consisting of four objects with four outputs and a transfer unit was carried out. In this test, communication was achieved successfully. It was presented in the study that VLC can be used in the web of things architecture. In the future, it is envisaged to use this system as a safe and economical system in indoor environments.

Higway Criuse Control System for Vehicles using Low Power RF and Can Protocol

Nowadays mishaps are happening much of the time, causing destruction of numerous individuals by committing unassuming errors while driving (in school zone, slopes region, and roadways). In any case, once in a while it may not be conceivable to see the billboards put by the Highway Department to caution the drivers in such sort of spots and there is an opportunity for mishap. The headway in the processor innovation and microcontrollers has opened another framework intended to forestall the mishaps caused because of carelessness of drivers in observing rush hour gridlock flags close by the street and different abnormalities on the streets. So to suggest the driver about the zones and to consequently keep up the speed is cultivated by methods for low power RF innovation. The primary target is to plan an Electronic Display controller implied for vehicle's speed control and screens the zones, which runs on an implanted framework and can be hand crafted to fit into a vehicle's dashboard to show data on the vehicle. This framework whenever received by some state can successfully diminish the quantity of street mishaps brought about by speeding vehicles losing control of the vehicle at speed breakers or by driver's carelessness towards traffic signals. This paper presents another structure to control the speed of the vehicles at clumsy zones and security zone places for fixed time. The undertaking is made out of two separate units: Zone status transmitter unit, Electronic Display and Control unit. When the street sign is gotten from the zones, the vehicle's Electronic Display Controller Unit cautions the driver, to lessen the speed as indicated by the zone; it hangs tight for driver's reaction and diminishes the speed of vehicle consequently with CAN Protocol.