ADAMA UNIVERSITYSCHOOL OF ENGINEERING AND INFORMATION TECHNOLOGY DEPARTMENT OF ELECTRICAL ENGINEERING
SENIOR PROJECT REPORT FOR BSc THESIS ON PLC BASED IRRIGATION SYSTEM CONTROL
SUBMITTED TO: ATO KEMAL IBRAHIM
PREPARED BY GROUP # 1 1. ADUGNA BEKELE 2. 3. DULLA MEKONNEN EMEBET TADESE
4. MESKEREM TADESE 5. NEWAY MOGES AUGUST, 2010
AbstractNew irrigation electrical control technologies could improve irrigation efficiency, promoting water conservation and reducing the environmental impacts. The objectives of this project were to avoid wastage of water and increase irrigation efficiency by using a PLC based irrigation system with the help of soil moisture sensor. It also improves the traditional irrigation system in Ethiopia enabling the irrigation system to have high efficiency and low water usage.The existing irrigation system being tedious, time consuming and very wasteful in water usage. The PLC based sprinkler irrigation system gives the best feature than the traditional one.
AcknowledgementsIn order to successfully accomplish our senior project on PLC based automation of irrigation system with case study on ADAMA UNIVERSITY garden watering system the help of many people was very important and unforgettable. So our kind and deep appreciation and thanks goes to our adviser Ato KEMAL IBRAHIM for his advice, spending his golden time, knowledge and bringing materials from different concerned bodies for the success of this project. Our next thanks goes to M/r WOLFGANG, chief of GTZ/ECBP further training section, and all his subordinates for their endless support and attempt to help us with any regards in their disposal. We would like to tank AU water supply section and wood work sections for their kindly cooperation and patience. Finally we would like to thanks all the teachers in ELT department
Table of contents Page Acknowledgement Abstract
1. Introduction. 1.1 Background of the project.. 1.2 Statement of the problem 1.3 Objective of the Project. 1.4 Scope of the Project 2. Description 2.1 Programmable Logic Controller (PLC)... 2.1.1 History of PLC 2.1.2 Basic functional sections of PLC. 2.1.3 Expansion module 2.1.4 Programming a PLC 2.1.5 PLC scan cycle. 2.1.6 Advantage of PLC.. 2.2 Solenoid valve.. 2.2.1 Definition. 2.2.2 Function 2.2.3 Operation principle.... 2.2.4 Types of solenoid valve. 2.3 Soil moisture sensor... 2.3.1 Types of soil moisture sensor 2.4 Soil moisture sensor installation 2.5 Level sensor 2.5.1 Definition.. 2.5.2 Types of level sensor 2.5.3 Application of level sensor 2.6 Description of the project 2.6.1 Design .. 2.6.2 Implementation 2.6.3 Test 3. .Resources 4. Conclusion 5. Recommendation 6. References 6.1 Appendix
Introduction1.1 Background of the project Irrigation in Ethiopia has lasted for decades. Ethiopia covers 12 river basins with an annual runoff volume of 122 billion m3 of water with an estimated 2.6 billion m3 of ground water potential. This amounts to 1743 m3 of water per person per year: a relatively large volume. But due to lack of water storage capacity and large spatial and temporal variations in rainfall, there is not enough water for most farmers to produce more than one crop per year with frequent crop failures due to dry spells and droughts. Moreover, there is significant erosion, reducing the productivity of farmland. [Awulachew] So irrigation being compulsory for Ethiopia; the government has recognized Ethiopias irrigation potential and has identified the important role of irrigation development for reducing vulnerability to inconsistent rain fall distribution and poverty reduction of the people. Traditional irrigation is very old in Ethiopia. The traditional small-scale schemes are, in general, simple river diversions. The diversion structures are elementary and subject to frequent damage by flood. 'Modern' irrigation was started at the beginning of the 1960s by private investors in the middle Awash valley where big sugar estates, fruit and cotton farms are found. With the 1975 rural land proclamation, the large irrigated farms were placed under the responsibility of the Ministry of State Farms. Almost all small-scale irrigation schemes built after 1975 were made into Producers' Cooperatives. [www.fao.org] Ethiopia has an estimated irrigation potential of 3.5 up to 4 million hectares (Awulachew et al. 2007b). During 2005/2006 the total estimated area of irrigated
agriculture in the country was 625,819 ha, which, in total, constitutes about 18% of the potential (MoWR 2006); of which traditional irrigation accounts for 479,049 hectares while 124,569 hectares of land was developed through medium and large scale irrigation schemes ( MoFED, 2007).
According to the Ministry of Water Resource (2002), there are four broad categories of irrigation systems in Ethiopia, namely; (i) traditional irrigation schemes; (ii) modern small-scale irrigation schemes, (iii) medium- to large-sc irrigation schemes, and (iv) large scale irrigation schemes. About 75 percent of the developed irrigation is small-scale, about three-quarters of which is traditional, and is mostly based on local practices and indigenous knowledge. Given that the overwhelming majority of farming activities in Ethiopia is small-scale, there could be a unique opportunity for positive interventions to stimulate agricultural production, especially if certain fundamental conditions are met. Experience in many parts of SSA has shown that with adequate community involvement in planning, design and management, SSIs can be more viable and sustainable than conventional largescale schemes from a number of perspectives (Merry et al., 2002). Sprinkler Irrigation is a method of supplying water for irrigation in a method similar to rainfall. Water is distributed through a network of pipes spread out on a field. The water from these pipes into the air and so irrigates the entire soil surface through many sprinkler heads. Sprinklers provide better coverage for small to large areas and are suitable for use on all types of fields. Total area to be irrigated is divided into small segments called irrigation blocks or zones and these zones are irrigated in sequence according to the flow of water. It is also adaptable nearly to all irrigable soils since sprinklers are available in a wide range of discharge capacity. It is suitable for almost all fields, crops as well as Vegetables and gardens: Residential, Industrial, Hotel, Resorts, Public & Government Enterprises, Golf Links, Race Courses. Water is a valuable resource and therefore its usage should be in an efficient manner. Also, water scarcity is one of the most important factors driving growth in agriculturebased industries in our country Ethiopia. For efficient use of water for irrigation, labor cost, etc., drives the need for highly efficient automated sprinkler irrigation systems. Automated sprinkler system has the following categories (a)Time based system. Time based automatic sprinkler systems is better to avoid being bothered with the routine work of lawn watering, but tend to set them and forget them. This method of
watering accomplishes the task of keeping the lawn green, but over the growing season uses significantly more water than the grass requires. This problem contribute to water waste and are not often fixed because the lawn is unnoticed moist most of the time. (b) Quantity based system. In volume based system, the preset amount of water can be applied in the field segments by using automatic volume controlled metering valves. Sequencing of metering values can also be done automatically. Even though the amount of water applied can be excess because the discharging of the moisture may vary in time. (c) Moisture sensor based system In the moisture sensing system the operation of irrigation valves are controlled by a controller get values from the moisture sensors placed directly in to the root zone. If there is sufficient moisture, then the sensor will prevent the sprinkler system from activating and applying water. However, if it senses that the soil is dry, it allows irrigation to take place.
Automatic sprinkler systems have the potential to save water if they are well designed, installed and maintained and it will give a great advantage for the owners and workers.[ Brent Q. Mecham] So, our project is a PLC based sprinkler irrigation system using moisture sensor which can give the best feature in giving effective watering and intense satisfaction of job well-done to bring an irrigation development in our country Ethiopia.
1.2 Statement of the problemIrrigation system has lasted years in Ethiopia which is traditional. Farmers are traditionally accustomed to directing flood (surface) water for supplementing their crops (spate irrigation).These irrigation systems have many drawbacks like wastage of water, high labor cost, timing problem, uniformity of water supply, so that each plant will not get the amount of water it needs, either too much or too little. Since the system is uncontrolled the soil is soaked too much .These systems have low requirements for infrastructure and technical equipment but need high labor inputs . So our project
comes up with a remedy to solve the above problem with high efficiency and low water usage.
1.3 Objective of the ProjectThe general objective of the project is to design automated control system sprinkler irrigation for the development of irrigation in our country.
Specific objective of the study are: 1. To design and implement a control system of sprinkler system for a Garden of Adama University 2. To minimize human intervention in agricultural irrigation industry . 3. To improve automation, control, and distribution technology in irrigation system. 4. To increase irrigation water utilization efficiency. 5. To enhance the transfer of irrigation technologies and management alternatives emphasizing