Agricultural robots are the fastest growing technology developed to perform various complex tasks that are difficult for humans to achieve. Recent news claims that the Japanese government has taken an initiative to use robotic operators in lands swamped by March 2011 tsunami. This “Dream project” was planned to involve unmanned tractors working in the farm on the disaster site. The robotic farmers are capable of cultivating vegetables, fruits, soybeans, wheat and rice, which are then packed in boxes and shipped across the country by this robotic technology. This process is accompanied by recycling of carbon dioxide using machinery in an attempt to reduce the use of fertilizers.
Solutions to Implement Precision Robotics for Agriculture
A single solution to implement precision agriculture is the development of a single gantry robot that can perform several precision agriculture related operations. The main objective of this system is to implement soil monitoring and precision irrigation on each crop, perform de-weeding and design a cultivated field using accurate robotic crop planning.
The Gantry Robotic System
The gantry is provided with three linear drives for positioning the robot at the desired location. These linear drives are designed with high precision as only simple and cost-effective sensors are used. This robot can be easily fixed to and detached from the frame on the field, thus ensuring effective sharing of a single robot by a number of farmers.
The key benefits of gantry robotic systems are:
- Robust design
- Convenient for precision agriculture
- Suitable for large working environment.
However, the costs of these robotic systems have to be reduced in order to increase their feasibility in agriculture.
Following this, Kumar S.K.N et al (2007) developed an inexpensive, fast gantry robot system that is suitable for applications with lighter payloads. The key components of the gantry system are described below:
- Linear drives - The drives used for horizontal displacements include a wheel rolling on a rail. The vertical displacements are achieved by linear screw drive attached to the bearing case of the wheel on the rail.
- Water supply – The robot has to be linked with an overhead water supply for supplying water to crops.
- Motors and controllers – It is necessary to power the linear drives using DC motors equipped with optical encoders. However, precise control of the motor is needed for correct positioning of the robots.
- Materials - The material used for gantry frame should be inexpensive, light in weight and strong. High density polyethylene was chosen as an ideal material based on these requirements.
- Power source - The robot has to be powered using an AC supply via wiring.
Example 1 - Robotic Milking
Robotic milking is the process of milking dairy animals under unmanned conditions. A farm involving the use of milking robots is different from the one that uses the conventional milking approach. It is necessary for a management to carefully plan for the location of the milking robots so that the robots are easily accessible to the cows. Initially, the cows are allowed to associate with the robots for three days. Then the cows are set free and those having a milking interval of more than 10 hours are selected for milking. The milking interval of these cows is gradually reduced. Then the next set of cows having 12 hours milking interval is selected for milking. The following video demonstrates the MR-S1 milking robot by Boumatic Robotics. This robotic system works by milking the robot from behind. The identification system to this robot is capable of recognizing when the cow is ready to be milked and is designed to determine the amount of concentrate required.
Example 2 - Automation of Crop Production
- Crop scouting – Accurate and timely data can be collected in an inexpensive manner with the presence of automated systems in the crop having sensors to evaluate health and status of the crop.
- Weed mapping - It is a method used for recording the density and position of various weed species using the automated machines.
- Robotic weeding -Several methods can be employed to kill the weeds. For example, the interface between the soil and the root is broken by tillage and wilting of weed plants.
- Micro spraying – In this, care should be taken not to damage the crop or disturb the soil while killing the weeds. This can be achieved using micro spray that releases very small amount of herbicide directly on the weed leaf. Automated machines can locate the position of an individual weed plant and spray the herbicide through a set of nozzles.
- Robotic irrigation – Water can be applied at variable rates over the predefined areas using a robotic irrigator developed in the form of a mechatronic sprinkler.
Future of Farms
With fully-automated farms in the future, robots can perform all the tasks like mowing, fertilizing, monitoring of pests and diseases, harvesting, tilling, etc. This also enables the farmers to just supervise the robots without the need to operate them. The key aspects of automated farms are the following:
- It facilitates 24/7 operation in the farm
- It improves safety
- It allows selective harvesting
- It sustains domestic agriculture
- It reduces chemical usage and labor needs
- It enables plant-level management
- It assists in precision pest management
- It helps small family farmers by enabling small farms to compete globally.
The following video by David Dorhout is a graduate of Iowa State University with a B.S. in Insect Biology & Behavior and a M.S. in Insect Ecology summarises the future of farming and discusses the concenpt of applying swarm robots in agriculture and talks about Prospero, a robotic farmer.
Research efforts are now beginning to invest more in the development of multi-robot vehicles as platforms for a robot farming system. These vehicles include an electronic robot vehicle that can provide crop information using sensors, and two-robot tractors capable of performing various implement functions. Application of inexpensive navigation sensors to the robot farming system makes the system economically adaptable with the environment. With the development of robot farming system, food production can be increased considerably and economically.
Sources and Further Reading
- Kumar S.K.N, Sudeep C S, Department of Mechanical Engineering, NIT, Surathkal, India, 2007, 13th National Conference on Mechanisms and Machines.
- Blackmore, B. S., Stout, W., Wang, M., and Runov, B. Robotic agriculture – the future of agricultural mechanisation? 5th European Conference on Precision Agriculture. ed. J. Stafford,V. The Netherlands, 2005, Wageningen Academic Publishers. pp.621-628.
- Noguchi.N, Barawid Jr.O.C, Professor, Laboratory of Vehicle Robotics, Graduate School of Agriculture, Hokkaido University, Japan,2011, 18th IFAC World Congress Milano, Italy.
- Japan to open robot farm in tsunami disaster zone