TRAVEL OF INQUIRY TRAJECTORIES
The path of inquiry that the group decided to Robolution Loyola Team is based on the PDCA model (Plan, Do, Check and Act), which allows the system to provide feedback for continuous improvement.
Across the entire project development was conducted a literature review in indexed databases, books and other primary and secondary sources.
Strengthening Project:
At this stage there was a preceding project feedback, which replanted some research points, mainly to strengthen the biological, automation and design of the dispenser of fruits and vegetables.
Planning:
At this stage it was step by step planning of all activities to be undertaken during the project, were assigned specific tasks to each team member, and the preliminary budget.
Biological Research:
Were visited several chain stores and market places in the city to observe the different factors that can affect fruit and vegetables, such as the manipulation by customers and employees of the place, without due precautions.
We conducted a bibliographic review which they found the results of research that have been made about the microorganisms present in fruits and vegetables exposed to the environment.
Design Phase:
We performed a redesign already had prototype in areas:
• Graphic: 3D model of the redesigned dispenser.
• Electronics: Weigh to feed inventory, sensing temperature and relative humidity and automation of the entire system.
Negotiation Stage:
They presented the project to a chain store that suggested some changes to the project that would fit the current market needs. We performed a prospective analysis to determine the projection of development and create business strategies for this.
Construction:
This stage is the most important has been for our group, appeared in several steps:
1. RELATIVE HUMIDITY CONTROL
ON-OFF Controller
The driver we use is one of the simplest in the control theory, a controller is turned on or off or On-Off, this is simply to compare the output of the system with a reference value or set-point, so I always sensed value equals the reference. Below is a graph of blocks representing the elements used in our device and its role in the control process.
It may be added also in our control system is not required that the signal is equal to the set point, but may be greater than or equal to the same.
Below are the steps to implement the control system electronically:
Converting analog signal from sensor HIH-4030 digital signal into the Arduino: As the signal from the sensor voltage is, we must examine the data sheet, which is the curve relating this physical variable to measure relative humidity the curve is shown below:
From this graph we two points to obtain a straight line, simplifying the model, which shows the linearity of the same
The points are taken:
The model of a linear equation is given by:
Where m is the slope and b is the y-intercept, whereby the first step is to find the slope by means of the formula:
Therefore m for this model is given by:
The y-intercept, b ie, is taken directly from the graph, therefore
The equation of the line is defined by 
Replacing physical variables:
Where in this last one obtain the relation between voltage and humidity, yet the process has not completed because the value sensed by the microcontroller, is not directly expressed as a measurement of voltage, but as a value proportional to the scale of resolution in bits, which in this case is 10bits.
The number of values or digital words in resolution, is calculated with the formula
, where n is the value of bits, and is the base two binary microcontroller therefore for our case, the amount of digital words is given by:
Each digital word translates a voltage value, which is given by the voltage window that covers the resolution, that is 5V Arduino, whereby each word or value change means an increase or decrease in 
, whereby delivered as very reliable.
With this in mind, we must change the equation, the units of voltage, digital words, bearing in mind that, meaning that there are
per volt words, the equation is then:
In this equation we isolate the variable HR, which is given that we obtain from the measurement sensor therefore.
Arduino Programming: With inferred above equation, s could get the value of HR so you can control the system from the reference signal to be maintained with the Arduino code to control the actuator on or off from the value of HR.
2. Methane Gas Measurement
It is proposed in this phase, perform a measurement of methane gas, because it is released by decomposition processes, which can be very useful as an indicator of the quality of the fruits that are in the device.
The sensor used is the Gas Sensor MQ-4, which has the ability to measure different gases as indicated by the graph, where the measurement value obtained is expressed in parts per million and depends on the calibration of the sensor, given by an array of resistors. In our case the cure of interest is that of CH4, represented by purple boxes.
The resistance value of MQ-4 is different for various types of gas concentration therefore, the sensitivity adjustment is needed to ensure a good measure. Mindful datasheet recommendations detector was calibrated to 5000 ppm CH4 concentration in the air, this was achieved by using the value of the load resistor (RL) to a value near 20KΩ.
3 Inventory System
· Electronic configuration
It starts with the purchase of a weight that has a capacity of 30 kilograms, using reverse engineering tool, to make a profit from MV to V intersects the load cell, then taking it to a fiberglass bakelite in which permeates a schematic design made in EAGLE 6.2.0., this amplifies the voltage signal obtained by the scale, as shown in the following image:
Then it performs a data acquisition, which resulted in a linear plot of the weight and the programming voltage required for the arduino.
· Programming in arduino
With data collection the programming was developed in version 1.0.1 of arduino one, for it was considered weight management and inventory for each type of fruit, in our case the apple (under study).
4. The construction of prototype acrylic dispenser:
We kept in mind the design in 3D, which served as a basis for making the molds and cut acrylic, then proceeded to hit each of the parties and became the assembly of circuits.
5. Design of the website to inform the client properties and benefits of fruits, redirected through QR codes, easily accessible via Android or SmartPhone:
This process proceeded to design the website in wix.com (https://robolutionloyolateam.wix.com/fruits-hangar #! Home / mainpage), which contains nutritional information, your ideal environment and others. Then use a QR code generator to bind to the website and thus the users can obtain from their devices with Android system.
Step Test:
At this stage, the different tests were carried out of the electronic components of the prototype. After the control system programming relative humidity sensors make mounting rails irrigation and control tests. There was an unsuccessful trial where the irrigation system was not receiving a signal on or off, according to this endeavor and many more corrections were made, thus obtaining the expected results last test, where the control system of humidity and step irrigation manage to maintain the ideal environment for fruits (apple, pear) and vegetables.
In the inventory process was weighing several tests to see the capacity of the load cell, and once had the maximum weight of the weight will start with the programming phase which weighs wirelessly communicates with the computer through the LabVIEW graphical interface.
Retrieved QR code generator, we test several devices with Android system and finally dovetails nicely with the website., Tablets and those detected were SmartPhone QR code, we were taken immediately to the website that informs users in different aspects of the fruit.
