Author:
- Sadaqat Ali from Department of Entomology, MNS-University of Agriculture Multan
- Sharjeel Ahmad from Department of Horticulture, MNS-University of Agriculture, Multan
An agricultural robotic is a robot which is deployed for agricultural purposes. Emerging applications of robots in agriculture include weed control, cloud seeding, planting seeds, harvesting, environmental monitoring and soil analysis.
Robotic technology in various disciplines of agriculture
A robotic is an automatic device that performs functions normally ascribed to humans or simply a machine in the form of human. It is a machine that senses the environment, processes and responds to the sensor’s information with a computer command. They are man-made mechanical devices that can move by themselves and whose motion must be modeled, planned, sensed, actuated and controlled by programming. It will perform its task or functions day and night without complaining. Most of the robots have at least five parts i.e. sensors, effectors, actuators, controller and common-effectors. Robots never grow tired but can still have a risk of malfunctioning when maintenance is not conducted properly. Agricultural robotics is the logical proliferation of an automation technology into bio-systems such as agriculture, forestry, green house and horticulture
The way the robotic play important role in pesticide application
One of the most frequent and important task in agriculture is the application of fungicides, herbicides and insecticides. It is frequent because diseases are a common occurrence on plants which affect the plant production and it is important because it can have a significant impact on crop yield and quality. Fungicides herbicides and insecticides are all pesticides used in plant protection.
Current methods either mechanical or manual used for pesticide application include human involvement. Excessive amount of pesticides released to the surrounding environment and the exposure of the farmers to these dangerous chemicals during the spraying process. Robotic technology is an alternative method for spraying in agriculture which provides multiple benefits such as safety sustainability and environmental impact. In terms of safety, it removes the farmer from the exposure to dangerous chemicals. In addition less pesticides means healthier food products for the consumer.
In terms of agriculture sustainability robotic technology can provide a way to reduce inputs and make the most efficient usage of pesticide controls. Furthermore targeted spraying can have a significant reduction on environmental impact since with the current methods a major fraction of the pesticides sprayed accumulate in the soil. Many systems have been developed for various agricultural tasks such as monitoring, harvesting, spraying, weeding, cultivation and planting. A comprehensive review of automation and robots in agriculture identifies the challenges of robotic systems in agriculture and describes the different automation systems with application examples.
Aerial robots in precision Agriculture
One of the first applications of UAVs in precision agriculture was their use to measure the water stress in agricultural holdings. Nowadays, the UAVs are equipped with thermal and hyper spectral cameras as well as fluorescence sensors. An interesting experiment is reported where the authors produced a controlled deficit of irrigation to generate a gradient of water stress in a citrus orchard. They compared the data obtained by the micro‐thermal and hyper spectral cameras boarded on a fixed‐wing unmanned aircraft with the measurements on the leaves validating the aerial methods to measure the water stress. Similar works can be found in which show the feasibility and benefits of the aerial thermal imagery to improve the irrigation.
Another use of aerial vehicles in precision agriculture is the monitoring of crops to predict yields, properly calculate the amount of fungicides and fertilizers and detect pathogen. RGB camera was used to estimate the biomass of barley exploitation under two different nitrogen treatments. The results were cross‐validated with five different crop surface models based on the height of the plant.
Robotics in weeds control
Typical weed control methods include among others mechanical or physical methods; herbicide application, pre-emergence or post-emergence tillage, cultural control and biological control. Although the technology for tractor-mounted real-time weed detection and control has yet to exist the concept of automated selective spraying of weeds in agricultural fields has a great potential for reducing economic and environmental costs while maintaining high level of weed control. Different technologies for weed detection, management and spatial variable application of herbicide studies had been introduced during the last decade and importantly a broad range of new technologies for precision agriculture has been developed and implemented in agricultural practices.
These technologies can be categorized into three classes:
A. Crop and yield monitors and related software (e.g. GreenStarTM, Yara N-sensor TM etc).
B. Precision Agricultural Technologies (e.g. Agro GuideTM, FarmWorksTM etc).
C. Automatic Control Systems (e.g. AutoFarmTM, TruPathTM, AutopilotTM etc).
Generally applicable system requires technologies that can handle high level of complexity using artificial intelligence agent: a system that detects or perceives environmental changes and takes actions that maximize its chance of success. There are basically three principle components of designing automatic weed system:
1. A sensor system which identifies localized and measures important physical and biological properties of the agricultural system.
2. A management model processing data and information system on biological efficacies of control methods, optimizing treatments, environmental constraint, density and composition of pest and decision-making algorithms.
3. Actuator, a precision control implement e.g. sprayer, e-nose
Mesh Eye role in agricultural applications
It is a powerful smart camera with a good resolution that speck intelligence surveillance system with the capacity to revolve continuously in relation to the range, size, position of a moving target within the range if its field. Data image capture will then trigger color camera module and thereby procure high image resolution of the object. It uses applications such as radio transceiver, thumb processor, Agilant 2700VGA camera module and 256KB of flash memory among others. Image processing can be used in agricultural applications for the following purposes:
- To detect diseases on leaf, stem and fruit.
- To quantify affected area by the disease.
- To find shape of affected area.
- To determine color of affected area.
- To determine size and shape of fruits
Effective applications of robots
Applications of robots are recently sporadically spreading every day as the opportunity of replacing human operators provides effective solutions and return on investment. However robots are especially important when the duties that are needed to be performed are potentially dangerous or harmful for workers or when conservative issues need to be addressed.
Wheel drive weed controller
A weed controller is a four-wheel-drive weed-seeking robotics that was developed with weeding functions. Crops growing in rows can be weeded by running a hoe between the crop rows. It possesses vision systems and an intelligent hoe that enables it identifies the rows of crops and steer accurately between them hence considerably reducing the need for herbicides. Weeding robots are robotics running around the paddy field by using the information given from the direction sensor and the GPS receiver. Weed identification is based on color photography and weed maps.
Role of robotic gantry
Robotic gantry can be used for liquid or fertilizer spray and importantly can regulate its functions in accordance to the change in weather conditions. This improve steadiness because a sensor could be mounted so that if windy the gantry could halt and wait until favorable conditions improved.
Micro and macro sprayers
These are machine vision with a micro spray that can identify locations and position of weeds individually and a set of plungers are arranged close together with ability to squirt a herbicide on to the weeds within the close to crop area. However, within close-to-crop area care must be taken to avoid any damage that could disturb the crops or soil. Research has shown that splashing can be reduced when a gel is used as a carrier rather than water.
However, other experiments have shown that when appropriate quantity of herbicide is introduced in the right way and order at the right time then usage of herbicide can be effectively reduced to about 1 g/ha for an infestation of 100 weeds/m2. Micro-sprayer system research is presently under development. Macro-sprayer can be utilized efficiently especially under large farms area. Most of the manufacturers tend to produce equipment used for larger and bigger machines. The robotic gantry can be multi-purpose for either liquid spray or fertilizer application and it could be enabled to automatically regulate its functions according to the weather fluctuations and conditions and if rainy or windy it could suspend its activity until favorable conditions improved.
Multi‐robotic systems
Sometimes, single robots are not able to perform some complex tasks or to perform simple tasks in the required time. In these cases, robot teams might provide some advantages over single robots such as their effectiveness, efficiency, flexibility and fault tolerance. Most of the cases of robot teams for agricultural tasks reported by the literature are homogeneous. Using a fleet of UAVs instead of a single UAV for collecting data in large areas is common and there are multiple techniques for area distribution and path planning.
For instance, a team of small UAVs with low‐cost cameras can be applied to control the exploitation and management of water obtaining the same results than a single UAV equipped with a better camera and providing the operation with more robustness. Nevertheless, some agricultural applications require heterogeneous robot teams. The most common situation is when the task consists of operations that are more effective from the air and others that are more effective from the ground. For instance, aerial robots are able to efficiently cover large fields taking pictures and collecting data like distribution of water or location of weeds whereas ground robots can actuate on the crops with more robustness and precision I.e. watering or applying treatments. Therefore, the heterogeneous multi‐robot systems often combine the advantages and compensate the drawbacks of different robots.
Special robots for various operations
The traditional ground robots present several limitations related to the constraints of wheeled and caterpillar motion. Additionally, the use of aerial robots is not always possible especially when the task should be performed on surface or indoor. Sphere robots are systems whose movements are produced by instability. This type of robots is used in several applications and scenarios such as exploration and surveillance. Rosphere is described by their authors as a new low‐cost spherical robot for measuring soil temperature and moisture in precision agriculture. In comparison to wheeled robots with similar size and capabilities, the Rosphere is much lighter and robust in irregular terrains.