Agriculture has always been the fundamental pillar in the production of resources. Its methods have remained the same over time, despite the exponential evolution of the technical means put in place.
However, the means of exploiting data on physical quantities still have room for improvement in terms of development.
Indeed, many sensors for agriculture currently exist on the market, such as oxygen, temperature, water content, salinity and pH sensors. Nevertheless, their ergonomics can be improved as well as their adaptability according to needs.
These sensors allow the acquisition of information in real time as well as monitoring of soil studies and therefore plant development. Moreover, the system aims to make connected objects real decision support tools to improve practices such as watering or the space required between 2 successive plantings, in the service of the environment and the economy.
Our system must be able to record data and transmit it in digital form to a computer or a smartphone. It transforms the physical quantity sought into an electrical impulse, and transmitted via a wireless communication module.
All of these quantities must be within the primordial thresholds to ensure the favourable development of the plantation we are trying to implement.
Our objective will then be to design a system composed of existing physico-chemical sensors measuring various physical quantities in a single prototype. It will be composed of 3 main parts, which are the sensors, the electronic processing with an Arduino Uno or Raspberry pi card, and finally the wireless transmission. It will take its place in applications of soil quality control, physico-chemical analysis, for domestic applications, or for applications in agriculture. We will then transmit the data using a wireless transmission technique.
To do so, we will conduct a market analysis of current systems according to the most common needs, target applications, architectures and transmission modes. To complete this study, we will then focus on the scientific characteristics of the sensors and their electronic architecture, by studying the uncertainties, the measurement ranges of the sensors, their resolutions, their sensitivities and their consumption. In addition, these various points will enable us to dimension the system and analyse its final costs.
Our sensor system will be composed of a 50 cm deep probe. The non-submerged part corresponds to the bluetooth module, which is connected by cable to the submerged sensors.
Our system will target the agricultural sector on several scales: hundreds of hectares per km^2. Within our project, we will focus on a rectangular area of 1km^2 in order to give a small-scale idea of the use of the system. Thus, on a larger scale, we will multiply the number of systems according to their range, the transmission mode used (wifi, wired, bluetooth), the presence of relay points to transmit the measured data via bluetooth over a larger area...
In addition to being influenced by the surface area, the system is also driven by a targeted crop, in this case a vegetable garden, with some fruits growing on the land such as melons and vines, but also vegetables and wheat.
Depending on the ranges of our sensors and the chosen surface, we will have only one system in our case: the presence of several sensor systems is aberrant because for a surface of 1km^2, the physico-chemical characteristics measured by the sensor are the same on a short scale. Indeed, the evolution of temperature or oxygen between several hundred meters is of course negligible.
Situated in the center of the field with a volume of influence ranging from 700 to 1000 mL, we can take all the necessary information to evaluate a land suitable for the development of a plantation.
With 2 measurements per day at the extremes of the daily temperatures, we will be able to draw up a table on the evolution of all the physical quantities.
In order to process and condition the data measured by the sensor, we will use the microcontroller Arduino uno, or the mini computer Raspberry pi.
At the transmission level, it is essential because it will condition the customers targeted by this system. Indeed, a more efficient wireless transmission module will be more expensive, especially if we have a higher range with a more advanced bluetooth technology for example.
In addition, in the agricultural environment, transmissions via wi-fi and mobile networks seem impossible depending on conditions and circumstances in the countryside, for example.
The five elements that define data transmission :
- the source produces the message we are going to transmit.
- the transmitter produces a signal adapted to the transmission channel.
- the transmission channel is the link between the sender and receiver.
- the receiver picks up the signal and recreates the message.
- the receiver processes the received message.
Tutors : Martine VILLEGAS - Lucas LETAILLEURS