Simple Microcontroller Research Articles

Stretchable, Flexible, Scalable Smart Skin Sensors for Robotic Position and Force Estimation.

The design and validation of a continuously stretchable and flexible skin sensor for collaborative robotic applications is outlined. The skin consists of a PDMS skin doped with Carbon Nanotubes and the addition of conductive fabric, connected by only five wires to a simple microcontroller. The accuracy is characterized in position as well as force, and the skin is also tested under uniaxial stretch. There are also two examples of practical implementations in collaborative robotic applications. The stationary position estimate has an RMSE of mm, and the sensor error stays within mm even under stretch. The skin consistently provides an emergency stop command at only N of force and is shown to maintain a collaboration force of 10 N in a collaborative control experiment.

A Generalized and Flexible Control Scheme for Photovoltaic Grid-Tie Microinverters

In this paper, design and implementation of a flyback photovoltaic (PV) microinverter based on the direct digital synthesis (DDS) technique has been described for both the standalone and the grid-connected operation. The DDS technique adopted provides flexibility in the implementation of various control schemes of the PV microinverter on a simple low-cost digital signal processing type of microprocessor (dsPIC). As compared with the conventional look-up-table method used for generating sinusoidal output voltage waveforms by digital signal processing, a much higher resolution can be obtained in the voltage phase angle and magnitude owing to the adaptive nature of the look-up table implemented within the DDS architecture. The DDS technique is used in the implementation of all control schemes of a PV microinverter, such as maximum power point tracking (MPPT), phase-locked-loop (PLL), anti-islanding, and low-voltage ride-though (LVRT), with an integrated software run on a simple microcontroller. A dedicated computer simulation model is developed, where the PV panel model, the PLL in DQ reference frame, the MPPT algorithm, and the anti-islanding and LVRT features are all taken into account. The experimental results obtained on a 120-W PV flyback microinverter have verified the validity of the proposed technique for both the steady-state and the transient-state operation. The DDS technique is thus found to be quite convenient for application to module integrated converters.

Speech Recognition Based Home Automation System using Raspberry Pi and Zigbee

In this era, there is a great revolution in the home automation industry. Considerable development in speech recognition software and wireless communication modules has given home automation a new edge. This system is very helpful for medical patients, disabled and elder people, especially those who live all alone without any helping hand. The home automation system is separated in two major sections, base station and remote station. The base station and remote station are wirelessly connected through low powered RF ZIGBEE wireless communication module, which is an IEEE 802.15.4 standard. For speech recognition purposes, one of the finest credit card sized computers, Raspberry pi, is used within the base station. All along with this a simple microcontroller is used to control the switching of electrical appliances and lights of home within remote station, which works according to the command generated from base station. The aim of this paper work is to design a speech recognition based home automation system which is most efficient, user friendly, low in cost, compact in size, easy to install and latest in technology.

Distributed measurement system with data transmission secured using XXTEA algorithm

The paper deals with wireless data transmission security in the distributed measurement and control system. An overview of cryptographic algorithms was presented paying special attention to the algorithm dedicated to units with low processing power, which is important due to minimization of energy consumption. Measurement modules equipped with simple microcontrollers send data wirelessly to the central unit. The transmission was secured using modified XXTEA algorithm assuring low requirements for resource usage.

A low cost microcontroller-based automated irrigation system for two Ethiopian crops in a dry area

Maintaining soil water level is a necessary and pre-requisite for optimum crops production. Water is the essential elements for proper growth of crops in its optimum level; however its excessiveness should be avoided. Since irrigation is a dominant consumer of water, there must be a system which regulates the level of water use so that the irrigation field is neither over-irrigated nor under-irrigated. Over time, systems have been implemented towards realizing this objective and most of them employ micro-controller based irrigation systems. These systems offer several technological advantages but are unaffordable, bulky, difficult to maintain and less accepted by the technologically unskilled workers in the rural scenario. The aim of this paper is to design a simple, easy to install, monitor and indicate the level of soil moisture that is continuously controlled in order to achieve maximum crops growth and simultaneously to optimize the available irrigation resources, water and etc. A simple microcontroller based circuit is used coupled with relay units which control the water pumps. The use of easily available components reduces the manufacturing and maintenance costs. This makes the proposed system to be an economical, appropriate and a low maintenance solution for applications, especially in rural areas and not only for small scale agriculturists but also large scale too. The physical implementation result of the proposed system and its simulation result are tested and checked for consistence and correctness.Keywords: Microcontroller, Automated Irrigation, Soil Humidity, Crops

Study of soil moisture sensor for landslide early warning system: Experiment in laboratory scale

The high rate of rainfall is the main trigger factor in many cases of landslides. However, each type of soils has unique characteristics and behavior concerning the rainfall infiltration. Therefore, early warning system of landslide will be more accurate by monitoring the changes of ground water condition. In this study, the monitoring of ground water changes was designed by using soil moisture sensor and simple microcontroller for data processing. The performance of soil moisture sensor was calibrated using the gravimetric method. To determine the soil characteristic and behavior with respect to water content that induce landslides, an experiment involving small-scale landslide model was conducted. From these experiments, the electric resistance of the soil increased as soil water content increases. The increase of soil water content led to the rise of the pore pressure and soil weight which could cause soil vulnerability to the movement. In addition, the various soil types were used to determine the responses of soils that induce the slope failure. Experimental results showed that each type of soils has different volumetric water content, soil matrix suction and shear strength of the slope. This condition influenced the slope stability that trigger of landslide.

Novel SVPWM based on first order equation

PWM plays an important role in generating sinusoidal waveform for variable voltage variable frequency drives (VVVFD's) with a minimum harmonic level. PWM techniques have many methods in implementation ranging from a relatively simple method such as modulating sine wave to the advanced Space Vector PWM technique SVPWM. The SVPWM has a dense calculation that requires considerable processor time for execution. The proposed technique requires simple calculations and can be implemented using simple microcontrollers. The calculations of the proposed SVPWM are based on first order equations rather than trigonometric functions requiring either huge lookup tables for fetching or too many instruction cycles for calculation on a digital controller.

Dynamic Models of a Home Refrigerator

Abstract Home refrigerators produce a substantial part of the annual power consumption in an average household. To further improve the efficiency of these devices, new intelligent control solutions are required. These solutions necessitate the behaviour modeling of the refrigerators. We seek models with as simple structure as possible, since future intelligent controllers may use such models in real time, thus their evaluation must be feasible even on simple microcontrollers. We investigate various dynamic models to describe the behavior of the refrigerator, i.e. the cool-down and warm-up phases. For model parameter identification real data was collected from a real home refrigerator. Data processing, modeling and the parameter identification were performed in MATLAB environment.

Osciladores Caóticos implementados en Microcontrolador PIC18F

Introducción: Recientemente, los sistemas caóticos han llamado la atención de la comunidad científica internacional, debido a sus potenciales aplicaciones en varias ramas de la ciencia e ingeniería. Se han propuesto muchos trabajos con el fin de resolver algunos problemas interesantes, como la determinación de daños estructurales en los materiales o en sistemas de comunicaciones seguras. Sin embargo, la mayoría de estos trabajos se enfocan en sistemas caóticos en tiempo continuo, mientras que en muchos casos, es deseable que estos sistemas estén en el modo de tiempo discreto y puedan ser utilizados en tiempo real. Método: El presente trabajo propone la implementación experimental de tres osciladores caóticos discretizados en un microcontrolador simple. Los osciladores caóticos a implementar son muy conocidos y muy utilizados para ejemplificar posibles soluciones a diversos problemas: los osciladores de Lorenz, Rössler y Chen. Para lo cual, se utilizan tan solo un microcontrolador de bajo costo, unos cuantos resistores y un algoritmo de computación sencillo.Resultados: Se obtiene un sistema embebido de bajo costo y sencillo para implementar osciladores caóticos discretizados. Discusión o Conclusión: Se demuestra que los osciladores caóticos de Lorenz, Rössler y Chen pueden implementarse en cualquier microcontrolador de arquitectura basada en palabras de 18 bits o más. Además, se observa que el algoritmo propuesto se pude migrar de un oscilador a otro con solo sustituir el sistema caótico de ecuaciones.

The Backlight Control System Aimed at Reducing Crosstalk in Autostereoscopic Displays

In order to realize auto-stereoscopic display, a new directional optic structure was proposed in this article, by providing only a pair of parallax images time-sequentially, aided with the human eye tracking system, a multi-user stereo-parallax 3D displayer with full resolution was invented. Meanwhile, the backlight control system of this displayer based on the simple microcontroller was mainly focused, in view of the crosstalk existed in 3D displays, three effective methods to reduce crosstalk were put forward: reduced lit time ratio of the directional backlight, faster refresh LCD and the application of Kalman prediction interpolation. As the experimental results shows, these methods achieve a good performance in reducing crosstalk, and finally a strong 3D visual effect without loss of resolution is achieved. This article introduces an auto-stereoscopic display system with a new directional optic structure, and provides three effective methods to reduce crosstalk, which are all testified by experiments and the experimental result is shown in the article too.

Design of Low Cost Virtual Patient for Real Time ECG Analyzers

analysers have proved out to be very useful in the analysis of human heart beat and subsequently diagnosis of various human cardiovascular diseases. The design of these real time ECG analyzers is difficult since real time environment is not always available for the performance analysis of these analyzers. The existing ECG analyser makers are making use of expensive data restitution boards which generate real time signals for the performance analysis of ECG analyzers, which make the system even more expensive. Thus in this paper a virtual patient is proposed, which creates a real environment for the analysis of ECG analyzers by generating real time ECG signals from the database of real acquired data, by making use of simple Microcontroller. The signals generated by Microcontroller are seen as real signals coming from the instantaneous heart activities by the analyzer. The use of Microcontroller makes the system cost efficient and can be utilized as a test bench for the study of ECG signals at the laboratory level.

Implementation of a Chaotic Oscillator into a Simple Microcontroller

In this work, an experimental implementation of a chaotic oscillator is proposed. Many works have been proposed in order to solve some different interesting problems, such that determining structural damages in materials or for secure communications purpose. However, several approaches are in continuous-time, whereas in many cases, the systems are desired to be in discrete-time mode and in real time. In this work we present the implementation of one chaotic oscillator (Lorenz system) into a simple microcontroller, the implementation consists only of a low cost microcontroller, a few resistors and a simple algorithm. The algorithm could be easily modified to add or substitute the chaotic system.

Development of a Low-Cost Unmanned Aerial Vehicle Using Mini-Airship Structure for Acquiring Digital Image Platform

In this study, a low-design-cost and long-endurance unmanned aerial vehicle (UAV) based on the simple microcontroller board and mini-airship technique is proposed. Many well developed positioning sensors, such as GPS, 3-axis Gyroscope, Gravity-sensor and Magnetometer are used. In addition, the control model of Proportional-Integral-Derivative controller is applied to accomplish the long endurance purpose. Such a low-cost design has the potential to accelerate the application of UAV in a variety of video monitoring fields.

A real-time virtual machine implementation for small microcontrollers

A way to host a full general purpose virtual machine (VM) interpreter on a very small microcontroller platform is described. This machine provides a comprehensive set of general and enhanced functionality efficiently by abstracting the VM instruction set. Measurements were made on the execution of software programs in the virtual machine while running on the target platform in order to demonstrate the machine's capabilities. Additionally, multitasking capabilities were added to the baseline and found to perform efficiently within the VM. The results proved to be satisfactory and demonstrate that a robust virtual machine can be made available for very small embedded platforms based on simple microcontrollers, such as those that are widely found in aerospace applications.

Optimizing sensor movement planning for energy efficiency

Conserving the energy for motion is an important yet not-well-addressed problem in mobile sensor networks. In this article, we study the problem of optimizing sensor movement for energy efficiency. We adopt a complete energy model to characterize the entire energy consumption in movement. Based on the model, we propose an optimal trapezoidal velocity schedule for minimizing energy consumption when the road condition is uniform; and a corresponding velocity schedule for the variable road condition by using continuous-state dynamic programming. Considering the variety in motion hardware, we also design one velocity schedule for simple microcontrollers, and one velocity schedule for relatively complex microcontrollers, respectively. Simulation results show that our velocity planning may have significant impact on energy conservation.

A Smart Microcontroller-Based Iridium Satellite-Communication Architecture for a Remote Renewable Energy Source

With an increased focus on the utilization of green technologies and greater demands on the electric power grid, renewable energy is an important form of current and future power generation. With remote generation deployments, such as those based on wind energy, a cost-effective communication system with global coverage using satellite technology would be advantageous. The monitoring of remote generators for performance and maintenance issues is certainly necessary for any distributed-generation system. To offer a cost-effective satellite solution, a cost-optimization algorithm for minimizing data transmission while maximizing relevant telemetry data is required. This paper proposes a low-cost smart communications architecture using an Iridium Satellite System 9601 short-burst data transceiver and simple microcontroller technology. The microcontroller allows for simple optimization routines to be performed on the locally stored data. This proposed system was implemented and tested and recommendations are drawn on the usability of the developed communication system for monitoring a remote generation site.

A Microcontroller Instruction Set Simulator for EMI Prediction

This paper predicts programspsila effect of time-domain electromagnetic interference (EMI) on a simple microcontroller. Using the instruction current concept and a modified instruction set simulator (ISS) for this purpose, this paper can predict, in the time domain, accurate conducted EMI behaviors when different programs are running on this system. Different program codespsila EMI behaviors are predicted, and all of these codes fit well with the measurement results. The modified ISS is adapted to estimate the pipeline effect of a microcontroller and to give an accurate current profile of any complex multi-instruction program. By using the instruction current model and the proposed ISS, this paper can predict the EMI behavior of a very complex program-a simple home-made operating system (OS) kernel. To the best of our knowledge, this paper is the first work on observation and prediction of EMI behavior of an embedded system OS kernel.

Design and metrological applications of a low noise, high electrical isolation measurement unit

A digitally controlled voltage generation and measurement unit optimised for high-precision electrical metrology is described. It is optically isolated from the controlling computer and contains specially constructed isolated power supplies allowing continuous operation without the need to recharge batteries. The source has a simple microcontroller that is pre-programmed with firmware to control operation and to carry out simple repetitive measurement tasks, such as generation and quantisation of signals using uniform sampling. The merits of the developed unit are demonstrated by three example applications: (i) the application of the unit to control a Josephson voltage standard, (ii) the implementation of a transfer standard for the calibration of the electronic instrumentation of fatigue testing machines traceable to the primary electrical standards and (iii) the force measurement of an ion thruster traceable to the primary electrical standards at the industrial user level.

The idea of using artificial neural network in measurement system with hot probe for testing parameters of heat-insulating materials

The article presents a mathematical model of a measurement system with hot probe for testing thermal parameters of heat-insulating materials. Currently in situ measurement of thermal conductivity is widely done by the line heat source (LHS) method. The basic problem with this method is the number and type of the assumptions needed. In this study, another method was proposed to measure the thermal parameters by using an artificial neural network. The model of a nonstationary heat flow process in the sample of material with hot probe and auxiliary thermometer is based on a two-dimensional heat-conduction model. For solving a system of partial differential equations that describe the model, the finite element method (FEM) was applied. The measurement system uses an artificial neural network (ANN) to estimate the coefficients of inverse heat conduction problem for solid. The network determines the value of effective thermal conductivity and effective thermal diffusivity on the basis of temperature responses of hot probe and auxiliary thermometer. In developing of the ANN model, several configurations were evaluated. The optimal ANN model was capable of predicting the thermal conductivity values with a relative error <1%. The influence of measurands errors on identified values of the thermal parameters was analysed. Learning process and simulation analyses were conducted in the Matlab environment. It is possible to implement the architecture of a trained neural network with a simple microcontroller embedded system.

Fast Triangulation Method for An Ultrasonic Sonar System

The paper presents an approach to processing of measurement data obtained from ultrasonic system. The approach makes possible to simplify computing of object location. The important advantage of the proposed method is that it eliminates operations on float point numbers. Thus an algorithm based on this approach can be implemented using a simple microcontroller.