Field-Robot-Based Agriculture : “ RemoteFarming . 1 ” and “ BoniRob-Apps

Based on the autonomous field robot BoniRob, which was developed for plant phenotyping, the authors have created an enhanced platform BoniRob (V2). The design of BoniRob (V2) considers two main improvements: At first the robustness for continuous outdoor use is increased and secondly the robot now makes available a reusable platform that can serve for multiple agricultural purposes. The combination of the platform BoniRob (V2) and application modules (“BoniRob-Apps”) is comparable to the classical combination of a tractor and an implement. In order to demonstrate this new concept, the authors have implemented three BoniRob-Apps, which can be integrated in BoniRob (V2) via defined mechanical, electrical and logical interfaces. The research project RemoteFarming.1 goes even beyond the accomplishment of a specific task by a robot and demonstrates the integration of the BoniRob (V2) platform into agricultural processes. For that purpose innovative agricultural engineering is combined with webbased communication technologies. The target is to develop a robotic mechanical weed control system which integrates a human user as remote worker in the process. The robotic weed control system is used for intra row weed treatment in carrots at BBCH-scales 10 to 20 in organic farming. This task is today conducted by hand. Introduction In recent years a variety of field robot prototypes have been proposed. They cover several applications, such as scouting and sampling, precise variable rate application of pesticides and fertilizers as well as autonomous weeding [1][2]. However, until now there is no commercial application of autonomous field operation in agriculture available. This is partly due to open issues regarding safety and legal requirements of autonomous operations [3].Another problem of the presented prototypes for autonomous field robots is their conception as single-purpose robots, despite there being several applications with market potential [6]. As the single-purpose concept leads typically would lead high costs due to a low workload over the year (specific tasks are required over only a short period of time), the systems are not economically feasible yet. To overcome this barrier a new concept for a multipurpose field robot is shown here. Multipurpose field robot platform BoniRob (V2) The BoniRob (V2) platform has been designed as an improved version of the BoniRob crop scout, which has been announced by the authors [5]. The BoniRob (V2) is shown in Fig 1. Fig.1: BoniRob (V2) during a RemoteFarming.1 field trial It was reengineered with focus on robustness and reusability. This manifests in increases of power supply by the electrical generator, continuous and peak torque at the wheel drives as well as chassis clearance (Table 1). Table 1: Technical figures of BoniRob (V2) BoniRob crop scout BoniRob (V2) platform Power of electric generator 2.0 kW 2.6 kW Battery’s capacity 110 Ah 170 Ah Continuous drive torque (per wheel) 55 Nm 70 Nm Peak drive torque (per wheel) 110 Nm 240 Nm As it can be seen in Fig.1, the height adjustment of the entire robot body was replaced by vertically fixed arms for each wheel, which can be rotated in the horizontal plane for adjustment of track width and centration of the robot body over the row to be treated. The hydraulic height adjustment was replaced by a manual, mechanical height-adjustment module frame. Furthermore, all other hydraulic drives were replaced by electrical systems. The BoniRob-App concept Using the multipurpose field robot platform BoniRob (V2) as a carrier, supplier and base for multiple BoniRob-Apps can be compared to the traditional combination of a single tractor with multiple implements. BoniRob-Apps can be integrated into the platform using defined mechanical, electrical and logical interfaces. The module frame of 0.77 m x 0.75 m in the centre of the robot allows mechanically attaching the BoniRob-App (Fig. 2). The mounting height can be adjusted in a range of 0.4 m. The electrical connection is set up using a custom plug. This provides energy supply to the BoniRob-App and different voltage levels (230V AC, 24 V DC, 12 V DC, 5 V DC). Moreover, it allows linking the emergency stop infrastructure of platform and App, such that even the App can stop the entire robot in case of emergency. Also, the custom plug sets up a Gigabit-Ethernet connection to the host-computer on BoniRob (V2). The entire communication infrastructure on BoniRob (V2) and between platform and the Apps is designed using Ethernet and ROS [4]. A sequence controller with 2 levels opens the way for distributed drive control of the robot. In the row the App (level 2 sequence controller) can access the drive control. On the headland the platform (level 1 sequence controller) holds the access to the drive control and runs the turn procedure of the robot. This Fig. 2: Multiple BoniRob-Apps can be used in the same platform allows switching the access to the drive depending on the state including letting the App control the drive train of the robot in properly defined situations. Again, this can be compared to a tractor-implement combination. In recent years in the field of Tractor Implement Management advances have been made towards control of the tractor by the implement in specific situations, because the implement and its sensors are closer to the process and more specifically adapted to it. This also shows that BoniRob-Apps are more than just tools to be used with the BoniRob (V2) platform but smart combinations of mechanical and electrical systems together with processand application-specific intelligence. BoniRob-Apps: Demonstrating examples In order to demonstrate the new concept, the authors implemented three BoniRob-Apps: