Automatic irrigation control system

INHALTSVERZEICHNIS

ABSTRACT

CHAPTER 1
1.0.0 INTRODUCTION
1.0.1 JUSTIFICATION
1.0.2 RESEARCH QUESTION
1.0.3 OBJECTIVE
1.0.4 SCOPE
1.0.5 PROBLEM STATEMENT
1.0.6 SIGNIFICANCE AND CONTRIBUTION OF THE PROJECT
1.0.7 AIM
1.0.8 ASSUMPTIONS

CHAPTER 2
2.0.0 RESEARCH METHODOLOGY
2.0.1 CASE STUDY
2.0.2 LITERATURE REVIEW
2.0.3 PROJECT DESIGN
2.0.4 PROCEDURES FOLLOWED IN DESIGNING THE SYSTEM
2.0.5 IDENTIFICATION OF MEASURABLE VARIABLES
2.0.6 IDENTIFICATION OF THE HARDWARE AND SOFTWARE
2.0.7 Moisture preset levels
2.0.8 OVERVIEW OF TANA RIVER REGION
2.0.9 DATA COLLECTION METHODS
2.0.10 INTERVIEW ANALYSIS
2.0.11 OBSERVATION (SITE VISITS)
2.1.0 DATA QUALITY
2.1.1 DATA ANALYSIS AND INTERPRETATION
2.1.2 ANALYSIS OF QUALITATIVE DATA
2.1.3 DESIGN MODEL
2.1.6 COMPONENT EVALUATIONS
2.1.7 CONCLUSION

CHAPTER THREE
3.0.0 LITERATURE REVIEW
3.0.1Sensors
3.0.2 Solenoid valve
3.0.3 Microcontroller
3.0.4 GSM technology
3.0.5 COMPONENTS THEORY
3.0.6 Raised tank Water level Sensor
3.0.7 Comparator unit
3.0.8 Ideal op-amp
3.0.9 Switching Circuit
3.1.0 Dual tone multiple frequency
3.1.1 Liquid crystal display
3.1.2 Microcontroller PIC16F73
3.1.3 Microcontroller Circuitry

CHAPTER 4
4.0.0 DESIGN, FABRICATION AND TESTING
4.0.1 Program code
4.0.2 Circuit operation

CHAPTER 5
5 .0 .0 RESULTS ANALYSIS AND DISCUSSION
5.0.1 RESULTS
5.0.2 ANALYSIS AND DISCUSSION

CHAPTER 6 CONCLUSSION AND RECOMMENDATIONS
6.0.1 CONCLUSSION
6.0.2 RECOMMENDATIONS

CHAPTER SEVEN
7.0.0 COST ANALYSIS
7.0.1 Project Timeline
7.0.2 Bill of materials

REFERENCES

APPENDIX A: INTERVIEW QUESTIONS

APPENDIX B: N-CHANNEL ENHANCEMENT MODE FET 2N7000

APPENDIX C: 3 TERMINAL VOLTAGE REGULATOR LM7805

APPENDIX D: NPN SWITCHING TRANSISTORS 2N2222

APPENDIX E: LM 358

APPENDIX F: DTMF RECEIVER MT8870D/MT8870D-1

APPENDIX G: PIC 16F73

APPENDIX H: PICTURE OF SOURCE OF WATER

APPENDIX I: QC1602A LCD

ABSTRACT

This project is based on moisture sensor used to measure humidity content in the soil. The design portion involves mainly a global system for mobile communication and a control circuitry with a microcontroller. This project used some of the softwares like basic language for programming the application software to the microcontroller and visual basic for interfacing the hardware and mobile phone. Protel or workbench schematic software is used for designing the circuit diagram for this project and express prefabricated circuit board (PCB) software is used for designing. Since PCB making is a big process and involves a number of machineries which are expensive and was therefore outsourced. Using DTMF 8870 IC will act as an interface between the user and the system as it is a receiver which links the GSM network, the microcontroller pic16f73 contains the software which states the conditions of the system which can be displayed in a liquid crystal display and transmitted via mobile phone to the dual tone multiple frequency receiver which is part of the control system in the farm. New technologies help in increasing productivity with use of less manpower as well as conservation of water in the process.

Keywords: Network, Microcontroller, Conservation, Global system for mobile communication.

CHAPTER 1

1.0.0 INTRODUCTION

Irrigation systems are grouped into two major categories namely pressure and gravitational. Pressure system involves the use of drip irrigation and sprinklers but in gravitational system furrows and canals are utilized. It is observed that this methods when used in an irrigation system consume a lot of water and therefore contributes to wastage of this precious resource which mankind cannot survive without it, automation of irrigation offers control of water which leads to utilization of small quantities of water without affecting the overall yield of production in a farm, it’s major aim is to optimize and efficiently manage water going to an irrigation field. This eliminates the need of continual presence of an operator to control water during irrigation period and thus eliminates human errors to a minimum level. All decisions will be made by the microcontroller depending on the conditions obtained from the moisture sensor

Food supply and demand is challenge to the government of Kenya this is due to ever increasing population which is directly proportional to it’s food production, this implies that water which is the main ingredient in crop production will continue to diminish according to FAO to maintain food stability for the next three decades it is advisable to increase acreage of irrigated lands by 34% in all developing countries and also channeling 14% water should be extracted for farming.

Kenya is classified as a water deficit country according to the World Bank (2007), Institute of Economic Affairs, (2006), Clark and King (2004). By 2009 the Kenya population was 37 million according to Kenya National Bureau of Statistics (2009) and it was growing annually by almost a million which means by the year 2014 the population of Kenya is anticipated to be around 43 million . Kenya is endowed with a water resource of 595 cubic per metres squared which away far from the global annual poverty line of 1000 per cubic metre . According to NEMA (2003) the future of this very important resource may recede down to a further 250 cubic per metres in the next twelve years when compared to other changes occurring in sub-saharan Africa.

According to Fereres and Connor (2004) globally food production obtained through irrigation accounts for 40% of the total expected, whereby only about 17% of the land set aside is specifically utilized for food production. The only biggest water problem globally is scarcity as asserted by Jury and Vaux (2003). From the above statements, it is with no doubt that in the future there will be a crisis of water supplies if proper utilization techniques are not adhered to, water is life and it is inevitable in any society since without it agriculture will not flourish .changes of climate globally will affect the ratio of quantity and quality of life mankind will live, proper utilization of water is a matter of national importance to the government of Kenya and to achieve this goal technology should be adopted to control water in any irrigation scheme.

It is to this reason that I consider developing solution to enhance efficiency in food production. The core objective is to manage irrigation for optimum food production that will also prompt data to a remotely on every occurrence on the field with help of a mobile phone and a DTMF. The user will be able to switch ON and OFF the irrigation system.

Features of the intended system

This system normally sends signals via a mobile phone to the DTMF and if there is a problem in the system the operator of the farm can be notified and action is taken to restore the system to normalcy.

This system also detects water level and measures can be taken immediately in case there is no water in the reservoir

This system is applicable in isolated areas with large farms whereby operators are required to be in the fields most of the time to monitor the irrigation, it is with no doubt that this technology will be of great help to farmers as it requires few operators in the field as well as saves on water used for irrigation.

The commonly used automation systems are -:

Time based system

Open loop system

Computer based irrigation system

Real time feedback system

Volume based system

Closed loop system

Time based system makes use of controllers to gauge the amount of water to be applied in an irrigation system. According to Cardenas Lailhacar (2006) timers and controllers can give wrong information which may lead to over or under irrigation therefore requires proper programming and testing .open loop system makes use of a schedule which Bomen et. al (2006) described it as a timing of irrigation process for a period of time which either uses volume of water or time for control function.

Computer based irrigation control system is interface of hardware and software section which acts as the intelligent part of the system whose function is to monitor changes in the irrigation system via a computer and can alert the user if there is a problem in the system. Real time feedback system is determined by plant requirement and specific parameters set which Rajakumar (2008) describes sensors as a means of providing feedback to the controller to enable it to effect operation. Volume based system uses a predetermined volume of water which can be applied to the field once , this obtained by using valves with meters which enables control and lastly a closed loop system makes use of a feedback from either a single sensor or several sensors which provides the irrigation decisions to be carried out based on the data obtained.

1.0.1 JUSTIFICATION

The study was necessitated by the looming scarcity of water for industrial applications, human consumption and agriculture. The identification of irrigation as one of the drivers of vision 2030 justifies the need of utilization of water in an irrigation system. Secondly increasing food productivity through irrigation will insert a lot of pressure on water supplies and therefore the study will help in management to guard the future against effects arising from poor usage of water. Thirdly with only 19.6% of Kenyan land under irrigation to the NIB (2008) which uses half of available water, it is worrying trend which need urgent mitigation if more land is to be put under irrigation.

The use of manual irrigation consumes a lot of time apart from being labour intensive , it needs monitoring frequently but automatic systems can be programmed to turn ON and OFF the system depending on the parameter to be controlled .irrigation control methods used in Kenya are mostly manual and a lot of water is wasted during irrigation. This project seeks to help to minimize on water usage hence enhancing conservation.

1.0.2 RESEARCH QUESTION

In order to achieve the objectives of this project, the following research questions were formulated in designing an automatic irrigation control system which optimizes water in an irrigation system.

1. What modern methods can be used to determine water saving in irrigation systems?
2. What are the possible methods of controlling irrigation remotely?
3. What are the ways of cutting costs in an irrigation system?

1.0.3 OBJECTIVE

Main objective

The main objective of this project was s to design, construct and test an automatic irrigation control system.

General objectives

1. Recognize the need for water saving in irrigation systems
2. Use mobile phone to control an irrigation system
3. Reduce the number of workforce in the farm

1.0.4 SCOPE

This project is paradigm shift from manual irrigation to automatic irrigation. Sensors are used to monitor humidity level in the soil and the water level in the tank which are processed by the microcontroller indicating ON or OFF condition of the system.

1.0.5 PROBLEM STATEMENT

Irrigation has been identified as one of the pillars of achieving vision 2030 by the government of Kenya in 2007. In its manifesto dubbed Kenya vision 2030 the country aims to conserve water and start new ways of harvesting as well use of rain and underground water to promote agricultural productivity. Kenya is a water scarce country according to the world food programme, the vision 2030 initiative proposes intensified application of science, technology and innovation to raise productivity and efficiency but irrigation expansion is likely to increase the scarcity of water which will lead to the competition for the available content by irrigators, industries and pastoralists.. It recognizes the critical role played by research and development in accelerating economic development in all the newly industrialized countries of the world. Recently launched irrigation schemes e.g. the one million acre Galana-Kulalu irrigation scheme still embrace the use of manual irrigation which will involve use of more water since there is no control and therefore this project proposes the use of automatic irrigation control system.

1.0.6 SIGNIFICANCE AND CONTRIBUTION OF THE PROJECT

AICS is a method that utilizes automation and the use of a microcontroller makes it cheap in terms of cost and maintenance. Soil moisture content is used in various fields like agriculture to determine favorable conditions for growing various crops and also in environmental monitoring whereby biological changes can be observed in this project AICS will be able to control the amount of water used in an irrigation system by discharging the right amount at the right time.

1.0.7 AIM

The aim of this project is to critically assess the automation of an irrigation system using a moisture sensor and a microcontroller as the main brain of control. It is evident that if comparison is made with theoretical knowledge there are inherent problems associated with RF signals due to interference, and also moisture sensors give different readings in respect to the depth as well different soil samples.

1.0.8 ASSUMPTIONS

The following assumptions were made in this project;

1. It was assumed temperature had no effect on moisture readings
2. Interviews carried out were limited only to the people living around the Tana River Irrigation Scheme.

CHAPTER 2

2.0.0 RESEARCH METHODOLOGY

This chapter discusses the methods that have been used in collection and analysis of data, it explains the research design, sampling techniques and data collection methods used and describes how data collected from the research has been analyzed.

Research methodology is the means of carrying out a research process, it always starts by asking a research question and followed by subsequent ways of answering the questions and may result in an answer or several answers to show conclusive evidence to audience in contribution of new knowledge to an existing system or new invention. In this project a qualitative research concept was employed which consists of three methods-literature review, case study and project design. To carry out in depth investigations in the research area as well as answer the research questions the literature review and interviews were used to collect qualitative data whereas questionnaires were used to collect both qualitative and quantitative data. To ensure data quality, reliability and validity must be tested.

2.0.1 CASE STUDY

This is one of the most important methods of research used to carry out a study by observation study and to be able to learn and collect data about a particular area. In this project investigation is done about irrigation methods which tend to conserve on water usage used in irrigation schemes in Tana River delta. This will provide detailed process used in carrying out irrigation in the area. Case studies by definition are always carried in real world and thus posses a high degree of reality; according to (seaman, 1999) case studies are based mostly on qualitative data and quantitative data which always provide a better understanding of the studied phenomenon.

A case study may carry some features of other research methods for example a survey can be carried out or use of archival records for analysis may be the part of the data collection.

2.0.2 LITERATURE REVIEW

Literature review is an inevitable part of research since it gives a concrete knowledge of an area of research where someone intends to carry out and to learn more about this subject (see chapter 3: literature review). Literature review was carried out to identify research bottlenecks and helps one to come out with a refined research topic; this is achieved by learning from previous works done by other researchers in the same field.

2.0.3 PROJECT DESIGN

A project design is described as a plan that guides the investigator in the process of collecting, analyzing and interpreting observations; it is a logical model of proof that allows the researcher to draw inferences concerning casual relationship among variables under investigation, Yin (1994). The design covers sampling techniques as well as the data methods used.

Design is creation of an artifact or a prototype of automatic irrigation control system, the design stage is very useful stage because it is where the hardware components are determined which involve creation of circuit drawings which aid in actual fabrication of the artifact. A software program is also designed which helps to interface the system since the hardware cannot work without communication between various components. Researcher intends to make this work a contribution to an existing knowledge especially by using a great deal of data obtained from project design, literature review and case study.

The following aspects were put into consideration to achieve the design solution;

Water utilization and saving

Human interaction

Power consumption

Reliability

Future improvement

2.0.4 PROCEDURES FOLLOWED IN DESIGNING THE SYSTEM

Three general procedures were followed to appropriately select the control system to measure the amount of soil moisture in the farm.

2.0.5 IDENTIFICATION OF MEASURABLE VARIABLES

It is very much important to precisely identify the parameters that are going to be measured by the microcontroller data acquisition interface and how they are to be measured. The set variables typically used in agricultural farming are; temperature which affect the plant metabolic functions humidity affects the plant transpiration as well as the plant thermal control mechanisms soil moisture affects the salinity and PH of the irrigation water A sensor for measuring a variable is required to be readily available, accurate, and low in cost but if it is not available the variable cannot be incorporated to the control circuitry, therefore variables that cannot be continuously measured can be controlled in a limited way by the system e.g. measuring the nutrient value of the soil is very difficult to measure continuously over a period of time.

2.0.6 IDENTIFICATION OF THE HARDWARE AND SOFTWARE

In any control system functions are specified before deciding what hardware or software to use in the project. The model chosen must have the ability to:

Provide flexible and easy to use interface

It must ensure a high level of precision and also must the ability to resist noise It should allow for expansion to meet the needs of future growth

Control strategy

Control strategy is a important element in any control system, the simplest strategy is to use sensors which give threshold values such as the moisture sensor which brings directly changes in the system like actuating of devices at given set threshold either minimum or maximum level.

2.0.7 Moisture preset levels

The most important factor to be considered in any soil moisture measurement is the value of moisture content measured in unit of water fraction by volume; this is illustrated by the table below.

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Table1: maximum depletion of various soil textures.

In this project the voltage ranges from 0vdc to 5vdc and therefore the moisture sensor will be operating within this range, this system is set such that when moisture level is 15% the reading of the voltage should be 0.75vdc which signifies the minimum level that can trigger the system ON. At 40% the reading of the voltage should be 2vdc which is the maximum level for the system being ON and value above this will trigger the system OFF.

2.0.8 OVERVIEW OF TANA RIVER REGION

The Tana River is located to both Lamu and Tana River counties; it has a core delta that covers an area of 130,000ha which is mainly in Tana River district. It is classified as one of the largest wetlands in Kenya with rich diversity of flora and fauna and also it is a home for farmers, pastoralists and fishermen. The agriculture sector employs about 60% of the population while 40% work in the livestock sector, commercial irrigation of rice by TARDA is the only major modern farming ever started in the delta but currently there are also model farms for maize, beans, bananas and horticulture which are aimed to be rolled out in the mega irrigation scheme of Galana-Kulalu.

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Figure 1: Map of Tana River

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Figure2: Sample of land for irrigation

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Table 2 : Statistics of irrigation schemes in Tana River

2.0.9 DATA COLLECTION METHODS

The method of multi-strategy approach was used to collect data, this is also referred to as triangulation and it involves the use of more than one data in the study and thereafter the findings are cross checked Bryman (2001). Glazier and Powell (1996) recommended this approach as it tends to reflect and explain issues in a more accurate way than any other single measure. Moreover triangulation gives a researcher a greater confidence in the research findings than in the case when a single method is used Clark and Dawson (1999). The methods applied to achieve this triangulation effect are discussed below.

(a) Questionnaires

A questionnaire is a data collection technique through which people are asked to respond to the same set of questions in a predetermined order Gray (2004). Beside the advantages of allowing wide coverage, questionnaires save a lot of time and effort since a single set of questions is duplicated and send too many respondents. According to Gray (2004) and Bryman (2001) questionnaires are less costly and allow respondents to complete them at a time and place that suits them, thereby limiting any inferences and bias that could be caused by the presence of the researcher.

Several disadvantages are associated with this data collection technique as follows;

(i) Low response rate
(ii) Difficult in probing respondents since personal contact is lost
(iii) No allowance for respondents to ask questions should clarity be needed
(iv) Greater risk of missing data

Some of the drawbacks raised above made the researcher to adopt interview questions instead. This was prompted by the literacy levels of people in Tana River County and the questionnaire would have required explanations to give the respondents an insight into the study in order to elicit relevant and useful data. Therefore questionnaires were not found suitable for this study.

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