Electrical Engineering - 2750 Words

Electrical Engineering (Research Paper Sample) Content: Name: Instructor: Course: Date: INTRODUCTION The growth of crops in a greenhouse enables the farmers to grow crops at all times of the year irrespective of the season. Greenhouses allow the farmers to grow crops at a time when it would otherwise be impossible to grow on the outside fields because of the weather. The greenhouse maintains optimum conditions for reliable and efficient plant growth. The sun provides solar energy which when utilized brings about the greenhouse effect. Inside the greenhouse, the farmer must have adequate systems to control and maintain an optimum environment for the growth of different crops as described by Northern, Henry, and Rebecca on "Greenhouse Gardening." The greenhouse structure should be sufficiently transparent as demonstrated by Currey, and Lopez to the sunlight for the growth of the plants. The greenhouse should be adequately enclosed so as to minimize the heat loss through radiation. The sunlight is a vital element in plant growth. Plant makes their own food through the process of photos ynthesis. Light is a key element for photosynthesis to occur. However, the rate of photosynthesis is dependent on the light intensity, direction and duration. Background. Greenhouse crops are similar to the outside gardening crops in terms of nutrients and water. However, the greenhouse crops flourish well due to the optimum growth environment provided by the greenhouse. In addition, crop husbandry is simple and reliable in an enclosed setup of the greenhouse. Greenhouse cultivation, apart from providing and maintaining optimum growth environment, it also helps in prevention and control of disease and pests. The varying outdoor environment sometimes provide harboring conditions for the crop pests and diseases. Managing and controlling heating, ventilation, air circulation and cooling is of utmost importance and should be carefully accomplished for optimum crop productivity. The constant management and monitoring helps the farmers make good decisions and able to mitigate the problems caused by adverse conditions on the crops. PROBLEM STATEMENT AND JUSTIFICATION This project aims in developing a comprehensive automatic monitoring system for regulating the crop growth. Greenhouse are optimized with the right conditions, and they have grown increasingly important in the world's food security. In the greenhouse, the temperatures, soil aeration and moisture, humidity and light is controlled. Temperature, humidity, light and the length of the plant will be monitored and controlled. Greenhouse effect is associated with excess heat as described by Titchmarsh, especially when the sun intensity is very strong. Excessive heat to plants is sufficiently dangerous to the plant growth and can lead numerous plant related problems. It can lead to stunted growth in plants, damaged fruits, damaged leaves and can even lead the death of the crops. Different species of crops have different optimum growth temperatures. These optimum temperatures may be different for the stem and root. Solar radiation has the largest effect on the growing environment. In maintaining optimum growth temperatures, the farmers are met with challenges. In a general perspective summer, crops prevail well in temperatures of about ÂÂ  74Â ° to 84Â °F in the daytime and at night about 60Â ° to 75Â °F. These temperatures are lower on cloudy days since the plant is not photosynthesizing. Temperatures can rise or drop depending on the season. The farmer must identify the optimum temperature needed for the growth of his or her crops to adequately control it. ÂÂ  The crop temperature monitoring and control affects the rate of plant development. During the sunny seasons, the transpiration rate in plants is at its peak. There're is a lot evaporation from the soil. These two processes cause the humidity in the greenhouse to shoot to alarming levels. The warm air in the greenhouse maintains the moisture in vapor form. When the temperature falls especially at night, the moisture in the air condenses and forms water droplets in the form of due on the leaves and stems of the crops which are the cooler surfaces as described by Smith. The condensed moisture encourages fungal growth on the crops destroying them. The crops should be protected from this fungal infection by regulating the amount of humid in the greenhouse. Greenhouses have a relative humidity of about 80% during the high growth seasons and periods. When this level increases to around 90%, the crops have a real fungal issue. The light is important in photosynthesis and should be considered in the design of the greenhouse. Shade overhangs from the roof should be monitored and modified if they form a big shade on the crops. At the early age of seedling development light is of utmost importance and should be appropriately supplied. Fluorescent lights are incorporated with the greenhouse to provide the optimum light conditions for the young crops. Some crops require and flourish well in high light intensity such as tomatoes. High intensity discharge lighting systems with special lighting bulbs are installed in the greenhouse. They provide the sufficient light to the light-loving plants. The greenhouse crops will flourish well with the light entering the greenhouse and additional light from the induced lighting. It is important for the farmer to monitor the plant length. This is important in the growth of crops such as tomatoes. The crops may grow high, and regulation of this height is important. Controlling the height is also important to the growth of horticultural crops like flowers. The crops especially flowers should not exceed their maximum height necessities. Maintaining the required length and picking table for crops is important to ensure productivity. RELATED WORK A lot has been done and reported on greenhouse environment monitoring. In managing and controlling temperatures, the greenhouse has installed mechanisms to aid in ventilation. The ventilations can be natural or forced mechanically. In mechanical forced ventilation, the greenhouse is fitted with louvers, exhaust fans which are electrically operated. Forced ventilation provides cooling to the greenhouse when properly designed. In natural ventilation, the air is allowed to flow in and out of the greenhouse naturally. All is needed are the inlets. In most small scale greenhouse, there are is no electrical and electronic mechanisms used to control the humidity level. The farmers ensure adequate spacing and ensure the floors are well drained. However, large scale farmers have advanced automated electrical and mechanical mechanisms to maintain and regulate the humidity level in the greenhouse to a predetermined value suitable for the crops. Wireless based systems. Wireless sensor based greenhouse monitoring of the environment has been done with programmed control for moisture. This is demonstrated by Park to control temperatures and humidity in the greenhouse. They emphasize on moisture condensation control system in order to maintain the right temperature and humidity. This control will hinder fungal infection to the plants. A Prototype Greenhouse Environment Monitoring System is demonstrated by Kumar, which utilizes wireless based networks. INTECH demonstrates use of robot controlled system through a wireless network to acquire data in the greenhouse. Kelly uses a wireless network to design a system that uses temperature, light and humidity sensors to control the greenhouse environment and prevent the crops from a fungal infection caused by high humidity. In his article Khandewal demonstrates how to automate the greenhouse with GSM reporting. GSM wireless networks are used to inform the farmer on the various condition s in the greenhouse. PLC based control systems. Using PLC based control system for the control of the greenhouse environment. The PLC is programmed to control the greenhouse environment. Control of temperature and humidity is achieved using different sensors. The PLC automatically regulates the temperature and humidity levels in the greenhouse. Green house control systems monitor and regulate the temperatures, humidity and light intensity. The greenhouse controlled accessories include; fans, misting and fogging systems, vents, and cooling and heating systems. All this processes are automated as described by Hashimoto in automation of greenhouse systems. Challenges in greenhouse monitoring. The challenges are normally brought about by the selected sensor. The sensors must be installed in the greenhouse. The greenhouse is associated with high levels of humidity, dirt, and excessive exposure to sunlight. The selection of this instruments must be thorough for reliable control of the environment. The instruments must be accurate to deliver accurate and reliable sensor signals to the microcontroller. The instrument must be able to deal with high moisture condensation. For reliable monitoring and control the response time of the sensors must be small to ensure efficiency. Compatibility problems between the sensor's signal and the overall control system. Since the control module is an integration of many parts, it becomes a major problem in finding spare parts. Essence of my approach. This project prototype will monitor and control the greenhouse environment. The approach employed in this project is simple and easy to use. The components used in this project are easily accessed. Unlike other documented projects on greenhouse environment control, this project also incorporates an alarm to inform the farmer when the crops have reached a certain predetermined height. The laser sensor will detect a height of 1.5 meter and alarm the farmer through a buzzer to harvest the crops. The approach described in this project report is simple and easy to incorporate and utilize it in the greenhouse. With the flexibility of microcontroller based system, this design can be incorpor...