ISSN- 2394-5125 VOL 6, ISSUE 5, 2019 AGRICULTURAL ROBOTS: THE NEEDS AND LIMITATIONS IN LARGE SCALE COMMERCIALIZATION Rushali Pant1*, Jyoti Joshi2, Pushpendra Kumar3, Pravin P Patil4 1Department of Mechanical Engineering, Graphic Era Hill University, Dehradun, India 2,3,4Department of Mechanical Engineering, Graphic Era Deemed to be University, Dehradun, India Email: [email protected] Received: 10 July 2019 Revised and Accepted: 14 August 2019 ABSTRACT: Although agricultural field operations are complex, diverse, labor-intensive, and crop-directed, agricultural productivity has significantly and continuously increased over the centuries as a result of mechanization, intensification, and more recently, with the introduction of automation. The advent of agricultural robots has the potential to raise the quality of fresh produce, lower production costs, reduce the drudgery of manual labor, and, in some parts of the world, to compensate for the lack of workers in some agricultural sectors. A key feature of agricultural robots is that they must operate in unstructured environments without impairing the quality of work currently achieved. The main limiting factors are production inefficiencies and the lack of economic justification. Machines will inevitably become smarter and fully autonomous; it is only a matter of time. Increases in labor costs and the demand less arduous work, the demands for better quality of life and higher quality produce and the progressively decreasing cost of increasingly powerful computers, electronics and sensors, are all promoting the economic feasibility of agricultural autonomous robot systems. This paper presents a review of state of art robotic technologies and supporting tasks for applications in agricultural processes including sowing, ploughing, harvesting, etc . Keywords: Agriculture, Mobile robots, Tracking, Sowing. 1. INTRODUCTION The aim of introducing mechanization in agriculture is to increase the productivity and improve the quality while reducing the labor cost and time of operation. The productivity of agriculture processes can be increased by timeliness of operation and good quality of work. Currently, certain operations like tillage are done partially or completely neglected because of inadequate amount of power availability thus resulting in low yield crops. Automation in agriculture has resulted in increased productivity as well as improved social status of farmers all over the world. It is known that due to low production per hectare Indian farmers have the lowest earning per capita. Also, the physical exertion and life of toil are the reason that men of intelligence and ability avoids getting involved in agriculture. It is therefore favorable to reduce this to some extent. It can also be noted that the attitude of people towards agriculture and the status of farmers in India can be uplifted radically by empowering farmers with support of robots. Another query that most people have is that India has surplus labor and animals to carry out cultivation and farm mechanization would result in unemployment as seventy percent of population in India is dependent on agriculture. However, it is a fact that in coming years increased food requirement in the country could only be achieved by increasing the productivity which requires mechanized and effective labor that can perform multiple cropping processes efficiently and this can be achieved by mechanization and automation. Concerns over the increasing demand of food production are the main reason of introduction of automated machines or robots in the fields. Based on the characteristics of the surrounding environment, every domain of robotics is associated with either of the four categories: 1. Structured environment and structured object, example industrial domain; 2. Unstructured environment and structured object, example military applications; 3. Structured environment and unstructured object, example medical domain; 4. Unstructured environment and unstructured object, example agriculture [1, 2]. The complicated dynamics of agricultural environment makes it an arduous task to build a robotic system. 348 ISSN- 2394-5125 VOL 6, ISSUE 5, 2019 Table 1: Various domains in Robotics Various Robotics Domain OBJECTS Structured Unstructured Structured Industrial domain Medical ENVIRONMENT Unstructured Military, Space, Mining Agriculture domain Robots can be defined as a programmable machine that is capable of performing series of operations automatically. Robots are controlled by using a control system which is handled either externally by an operator or it can be embedded within the robot. Robots perform the given task in a humanlike manner with greater accuracy and high yield and reduces the manpower and workload under stable situations. Designing of autonomous robotic system has to overcome two important challenges; first to deal with non-linear real time response requirements underlying sensor-motor control formulations and second to deal with how to model and use human approach to address each different situation [3]. Agricultural processes are complex, labor-intensive, diverse and unique for each crop. Crop characteristics, environmental conditions, market demand, consumer preferences, and farmer’s capabilities affect the process. Therefore, the technology or system developed for a certain crop need not necessarily be applicable to another crop or different environmental conditions. The diversity of agricultural processes, complexes the generalization of automation. However, despite the advances in the field of robotics, not much commercial fully autonomous robots are available for agricultural applications. In the past few decades, many research projects have been carried out that never reached the implementation stage. This is mainly because unlike industrial applications which mostly deal with relatively simple, well-defined and predetermined tasks in a stable environment, agricultural processes deal with a complex, unstructured and dynamic environment. The complexity only increases while considering natural objects such as seeds, vegetables or fruits because of variation in shape, size, texture, orientation, position and color. Therefore, various factors such as environment conditions, landscape, payload, maneuverability, visibility, propulsion system, control system, navigation etc., have to be considered while designing a robot for performing agricultural tasks. Reliability and robustness can be considered the primary focus of the design. Another factor that affects the commercialization of automation for agriculture is the cost of developing a system and inability to perform the same task in different context. It can be said that the autonomous system developed for carrying out agricultural process should comply by the following rules: 1. The system should be feasible. 2. The system should be robust. 3. The cost of the robotic system should not exceed the cost of any concurrent system. Some other conditions that need to be fulfilled include increased production, better quality, uniformity, minimized uncertainty in production process and the system developed can efficiently carryout any task which is time consuming and labor intensive. This paper focuses on the review of robotic technologies and numerous supporting tasks that enables the robot to find its application in the field of agriculture. The application may vary depending upon several agricultural processes like ploughing, sowing, harvesting, irrigation, pest control etc. The remaining paper is organized in the following subsections: Section 2 presents a review of agricultural robots and the different supporting tasks such as navigation and path planning. In Section 3, various applications of robots in agricultural activities are described such as sowing, ploughing, harvesting, etc. 2. AGRICULTURAL ROBOTS Agricultural robots are designed to perform a specific task such as sowing, pruning, weeding, irrigation, fertilization, pest control, harvesting, handling and storage. These are the main task that needs to be performed by 349 ISSN- 2394-5125 VOL 6, ISSUE 5, 2019 the robot, but in order to complete these tasks, robot have to perform numerous other supporting tasks such as navigation, path planning, mobility and steering etc. (Fig. 1). One subsystem of autonomous robot controls one or more supporting tasks of the system. Continuous flow of information between the systems controlling the main and supporting tasks results in effective working of a robotic system. Fig. 1: Structure of Robot System to Perform some Agricultural Task [1]. 2.1 Mobility and Steering An effective subsystem is to be developed that maintains the ground contact, trajectory tracking, and helps in navigating the system. Ground contact in itself is a crucial parameter. The design of the robot frame should be flexible enough so as to continuously maintain the wheel contact with the ground. Also, the system should be capable of operating while neither getting stuck nor damaging the soil structure. Robots designed for agricultural purpose generally comprises of 4-wheel platform with either 2- or 4-wheel drive and 2- or 4-wheel steering. Some platforms with 6-wheel drive or tracked platforms are also used. Lin et al. [4] developed a 4 wheel-drive/ 4 wheel- steering robot system for wheat seeding purpose (Fig. 2). All wheels are able to perform steering and propulsion. The four wheels are capable of steering in any desired direction using four stepper motors. The propulsion of each wheel is controlled