Fuzzy Logic Control Solar-Powered Portable Cooling Box

There are still some areas in the country that are having difficulties receiving uninterrupted electricity for medical aid like vaccines or insulin that require maintenance at certain temperatures. A combination of renewable energy for electricity and portable cooling boxes for medical aid can be a tremendous solution to this problem. In this research, the temperature inside the portable cooling box is kept at 2–16 °C by Peltier units running on solar power. The temperature sensor indicates the inside box’s temperature and the current sensor indicates how much power is being generated. Depending on the variation in solar radiation, the entire system is powered by direct solar or batteries. All data is processed by the Arduino using a fuzzy inference system (FIS). At the end of the process, the prototype project achieved its goal and thus played an important role in providing healthcare resources to marginalized stakeholders.


Introduction
The negative environmental impact of burning fossil fuels has forced the energy research community to seriously consider renewable sources.To reduce the impact of harmful fuels on the environment, the necessary power generation through solar panels can be a cost-effective, clean medium without harmful effects on the environment.Due to a lack of power generation, improper distribution lines, or inaccessible remote areas, many are deprived of storing their daily necessities at certain temperatures.Different types of needs require different temperatures, such as for children's medicines, insulin for diabetics, or the maintenance of a mass vaccination program.In each case, it is important to find a useful storage temperature and maintain quality by storing accordingly.If these conditions are not met, the properties of these drugs can deteriorate due to temperature variation.This represents either an economic loss or therapeutic inactivity if the drug had already been administered to the patient [1].Thermal-level drugs must follow a "cold chain," the logistical steps that guarantee temperatures between 2 and 8 °C from production to final administration [2].This requires cooling systems, and, in this case, a continuous power supply is required.However, traditional electrical power distribution systems have failed in their reliability and accessibility to meet the needs of rural health areas in many underdeveloped countries [3].Taking this context into consideration and implementing a solution to it, a solar-powered system will generate power subject to the availability of sunlight, and for the convenience of carrying wherever needed, portable cooling boxes are available so that essential items can be used while maintaining the proper quality of the product.
IOP Publishing doi:10.1088/1757-899X/1305/1/012014 2 Fuzzy logic uses logic and a decision-making mechanism that has no set limits, like human logic.One of the most common implementations involves fuzzy logic-based control mechanisms.Fuzzy Logic Control (FLC) systems don't require complete model knowledge like other control systems like PID.The Fuzzy Logic Controller (FLC) is easy to realize in any required area due to its simple control structure, simple design, and low cost.Fuzzy logic is used to monitor nonlinear systems that are difficult to process mathematically.Non-probabilistic uncertainties are followed by fuzzy logic and fuzzy set theory [4].The development of the fuzzy theory of logic has now stimulated alternative ways of solving problems with automatic control.Based on these basic ideas of fuzzy logic, Mamdani and Assilian proposed fuzzy controllers that describe human control in linguistic form.Consequently, the first application of fuzzy control replaced a human operator [5].Existing techniques increase the efficiency of solar panels, including the improvement of materials [6], the introduction of cooling systems [7], methods for controlling maximum power [8], and the conversion of direct current into alternating current [9].As in the past [10], [11], and [12], many studies have been conducted to develop thermoelectric generators.because of improved health care.Therefore, this study was conducted to design a portable, solar-powered cooling box that can reach the temperature required for drug storage and can be used in rural areas where there is unreliable electricity to alleviate the problem of drug storage.This document provides the implementation done by connecting PV to Arduino [13], [14], [15], and if a Peltier connection is made with it, it can be useful for cooling medium purposes.Artificial intelligence algorithms have been shown to perform well in intelligent control of photovoltaic systems [16].In recent years, research in this area has focused on the control of MPPT using artificial intelligence technology [17], [18].However, it does not include a hardware implementation for the fuzzy controller presented in these two articles.In this research, fuzzy logic control was used in a specific prototype project to obtain specific results.Vaccine storage in rural areas with Peltier cooling powered by solar that can keep vaccines cold chain (2 °C to 8 °C) [19].But this research updated it from 2°C to 16°C so that it becomes useful for insulin too [20].This cooling storage can store other daily essentials for different purposes.There are many places in the world where the main grid connection has not yet been reached, but we cannot proceed without them in terms of security.In those rural places where there is no grid connection, it is challenging to carry the required medicine or vaccine and store it at a certain temperature.Because if the vaccine is not stored at the specified temperature, it may lose its effectiveness.Then that medicine or vaccine will not achieve the desired goal.This proposed prototype project is presented to overcome this problem by identifying it.It has a solar plate that collects the energy from the sunlight and stores it in a power storage battery.It is possible to operate even where there is no grid connection.It can also be used to store essential items at a certain temperature.The arrangement of the remaining article is as follows: Section Two presents the methodology with two subsections: system overview and system architecture.In section three, implementation has been described through three subsections, which are the power generation unit, the controlling unit, and the cooling unit.Section four covers the fuzzy logic controller design.The result and discussion are described in section five.The article is concluded, and finally, all the necessary references are added.

Methodology
This section attempts to present the complete methodology of the proposed project.First, an airtight box is made so that the outside temperature cannot enter and the inside temperature cannot escape outside the box.Then, the temperature inside the box is maintained with the help of a Peltier.Secondly, all the necessary hardware parts, such as the solar plateare placed on the top of the box and the rest are placed at the bottom likethe charge controller, battery, and sensors are placed inside the box.The display and the buzzer are kept outside so that the user can monitor the internal temperature and take necessary action when the buzzer sounds as programmed.Thirdly, the Fuzzy Inference System (FIS) has been adopted in the software in the proposed prototype model because it is very convenient to set the rules from its utilization.This low-level artificial language FIS makes it easy to perform desired tasks without knowing conventional programs.An artificial intelligence system built on a fuzzy set of IF-THEN rules is known as a fuzzy inference system (FIS).The fuzzy logic produces concepts are not only may be "true" or "false," but it can also produce partially true concepts, with a truth value that can be anywhere from completely accurate to completely false.There are four primary components.Firstly, fuzzification is the process of converting a real scalar value into a fuzzy set.Secondly, the knowledge base is dependent on IF-THEN rules.Thirdly, inference engines rely on human analysis processes to make fuzzy inferences between inputs and IF-THEN rules.Fourthly, defuzzification is the process of converting a fuzzy set obtained from the inference engine into a crisp value as output [22].

Ssystem Overview
The overall system is shown in Fig. 1.In this, solar energy from the solar plate was stored in the battery through the solar charge controller, which is an ACS 712 current sensor module used for battery level indicators that went to the Arduino along with DHT11 temperature sensor input.Those values were then processed and shown on the display.From the temperature sensor value, the Arduino processed those values and gave a command to the relay controlling the Peltier and cooler fan to be triggered.

System Architecture
In this section, the system flow chart can be seen in Fig. 2. The system first started and initialized the circuit, then read the temperature sensor value along with the current sensor value.The system would trigger the Peltier to rely upon the temperature sensor value exceeding the threshold value; otherwise, it would again check for the value.The system, on the other hand, would read the current sensor value; if the value fell below the threshold, the system would notify via a buzzer; the buzzer would also be activated when the relay was triggered.The value of battery life, which denotes the current sensor value and the temperature value, would be shown on the display attached to the system.

Implementation
The system has been implemented in three parts: a power generation unit, a controlling unit, and a cooling unit.This time, the Propose Prototype project implementation is divided into three parts so that the prototype model runs smoothly.First of all, power is a necessary and integral part of running any electrical project.So solar panels are used for power generation to collect uninterrupted green electricity around the clock.Also, in various remote areas where there is no power grid connection, the power obtained from sunlight can be stored in batteries for later use and the necessary medicines can be stored at a certain temperature so that the quality of the medicine or vaccine remains intact.Secondly, the technical description is added to the controlling unit, and the FIS system of low-level artificial intelligence is input as a program so that the cooling box is user-friendly for the users.There is a possibility that the people who will use it may not have enough technical knowledge.Thus, the author has tried to ensure that the cooling box can be installed and service provided according to the program.The third subsection presents the technical details of how the prototype proposed model will generate its temperature and store that temperature inside the box.Through these, all aspects of implementation have been presented.

Power Generation Unit
The power required for the cooling box, obtained from a 12-volt battery, is charged through a solar charge controller by a 70-watt solar plate in Fig. 3, making it portable to carry anywhere.The battery status was monitored in real-time via a current sensor and shown on a display.

Controlling Unit
The main controller of the system is shown in Fig. 4.This part consists of an Arduino Uno, a temperature sensor, and a relay.DHT11 temperature and humidity sensorsare used to obtain the temperature of the box.The temperature of the box is maintained from 8 to 16 degrees."The constant temperature can be obtained by turning on the controlling the Peltier." Figure4.Circuit diagram of the proposed system

Cooling Unit
The Peltier impact states that once an electrical current flows through a circuit comprising dissimilar conductors, thermal energies are absorbed from one junction and discharged at the opposite, making the former cooler and the latter hotter.This creates a thermal difference from the flowing current [21].The main element that is responsible for cooling is Peltier.In this case, we used a 12706 thermoelectric Peltier cooler operated at 12 volts and capable of using up to 70 watts.The operating temperature range is -30 to 70 degrees.The constant cooling was acquired via the temperature sensor value upon which the relay that was controlling the Peltier was turned on and off at the time shown in Fig. 5.For the DHT11 variable, three input Membership functions are "below 2 degrees," "temperature 2-16 degrees," and "up to 16 degrees," respectively; see Fig. 8. Another input variable for measuring state of charge is "SOC_from_Acs712," whose membership functions are "Low," "Medium," and "High."To denote the Relay Output variable two membership functions is "Relay_off = Peltier_off" and "Relay_on = Peltier_on".Another output "LCD_Display variable" with three membership functions is "SOC_Low," "SOC_Medium," and "SOC_High."Through this IF THEN ELSE operations initially 6 conditions had been applied such as if (DHT11 is below_2_ degree) then (Relay is Relay_off=Peltier-_off).Thus, the remaining five conditions are shown in Fig. 7.
Figure6.There are two inputs and outputs on FIS

Result and discussion
The testing has been carried out to evaluate the cooling impact of the entire assembly and determine if it can reach the desired temperature range of around 2°C to 16°C to preserve the efficacy of the insulin.It was accomplished by using various time frames.Tests have been run on the site itself to evaluate the system's performance.Fig. 10 illustrates the practical implementation of a circuit diagram with a desirable outcome.In Fig. 9, we can observe the DHT11 dropping below 2 degrees at this moment Relay=2 meant Relay_off because the relay no longer works below 3.75 volts.It appears that if rule 1 is (DHT11 is below_2_ degree) then (Relay is Relay_off=Peltier_off) satisfied.Similarly, for Acs 712, rule 6 was also satisfied because the SOC_from_Asc712 sensor is at 80; that means the LCD_Display indicates 83 and it represents SOC_High.In Fig. 10, the condition given in Rule 6 is if (SOC_from_Asc_712_sensor is low) then (LCD_Display is SOC_high).

Conclusion
In this research, steps have been taken to keep daily essentials at the right temperature, including medicines, and insulins which need to be stored at certain temperatures.The specified temperature is simultaneously obtained from the power from the solar panel, and the automatic temperature is maintained within 2-16 degrees through a relay on/off procedure.When the power is less to operate this system, then fuzzy control gives the command to take power from the battery.The chances of power cuts are low when this condition is satisfied.As further research, in this system,AC may be added via wire and also, attempts may be made to raise or lower its temperature or set a specific temperature.Then it is expected that it will be useful for various purposes besides medicine or vaccine storage.And for the people who are deprived of grid connections, it will be a new addition rather than a refrigerator.

Figure5.
Figure5.Placement of the Peltier inside the box 4. Fuzzy logic controller design Fig.6represents the DHT11 and ACS 712 sensors as two inputs.Relay and LCD Display are the two output variables for the fuzzy logic controller, respectively.There are three trapezoidal membership functions in each of the two inputs and three trapezoidal membership functions in each of the outputs.For the DHT11 variable, three input Membership functions are "below 2 degrees," "temperature 2-16 degrees," and "up to 16 degrees," respectively; see Fig.8.Another input variable for measuring state of charge is "SOC_from_Acs712," whose membership functions are "Low," "Medium," and "High."To denote the Relay Output variable two membership functions is "Relay_off = Peltier_off" and "Relay_on = Peltier_on".Another output "LCD_Display variable" with three membership functions is "SOC_Low," "SOC_Medium," and "SOC_High."Through this IF THEN ELSE operations initially 6 conditions had been applied such as if (DHT11 is below_2_ degree) then (Relay is Relay_off=Peltier-_off).Thus, the remaining five conditions are shown in Fig.7.

Figure10.
Figure10.Circuit implementation and rule 6 are shown on the LCD

Figure11.
Figure11.Surface viewer of the proposed model