Autonomous Platform for Data Acquisition and Mapping of Tree Parameters

Publikations-Art

Poster

Autoren

Jaeger-Hansen, C.L.; Meiser, V.; Selbeck, J.; Heisig, M.

Erscheinungsjahr

2013

Verlag

Edicions de la Universitat de Lleida

ISBN / ISSN / eISSN

978-84-695-8176-6

Tagungsname

European Conference on Precision Agriculture

Tagungsort

Lleida, Catalonia, Spain

In the ICT-AGRI project “3D-Mosaic: Advanced Monitoring of Tree Crops for Optimized Management - How to Cope With Variability in Soil and Plant Properties?” an autonomous platform was used to collect data from trees in an orchard. The platform should collect data from each tree, and during the process navigate autonomously through the orchard. The sensors were equipped on the platform and the complete setup was tested and used in a plum orchard. The platform was able to navigate autonomously and collect the data during the second field trial of the project. The complete system consists of the platform with sensors and software for navigation, a LiDAR for scanning the trees vertically, and a program for controlling the sensor and storing the tree scanning’s, a sensor tower with cameras for 3Dimages and infrared images along with software for controlling the sensor and storing the images. The navigation software executes a predefined mission, which were driving the robot through the orchard. During the mission the “Server Program” could send continue commands to the navigation software, which pauses by each waypoint. The Server Program also communicates with the clients (the programs who were controlling the sensors), the status of the
clients determined when the mission was paused and when it was continued. The status of the clients changes when they are collecting/not collecting data. This means it was possible to control the platform based on the status of the sensors.
The platform used for this project was the Armadillo Scout, it is an electrical powered robot for agricultural application. The platform equipped with the sensors for navigation and data acquisition. The autonomous navigation was done with the software framework MobotWare. It is a framework for controlling mobile robots, it is currently implemented on several machines ranging from small robot for education to a Claas Axion 840. In order to ensure simple and reliable data exchange between the navigation software and the sensor-control software (clients), a server-program was developed. The purpose of the Server Program was to commands back and forth between the programs. Since the programs were distributed over several computers the communication between the software had to be network-based.
The programs were connected to each other over a stream socket using TCP. The commands which were transmitted were constructed in accordance with a protocol designed specifically for this assignment. The structure of the protocol is based on XML, attributes and data were wrapped in XML-tags and transmitted.
The entire system ran autonomously in a plum orchard at the Bundessortenamt in Marquardt (Potsdam, Germany). The navigation software failed twice during the field trial, the logs from the navigations software did not show any errors, but the log from the operating system indicated a system failure. Which means the navigation failed due to hardware errors not software errors. The LiDAR data was recorded while the platform was moving and the sensor tower took pictures when the platform stopped in front of a tree, this strategy worked well, and ensured the quality of both LiDAR data and images. The average speed of the platform was 0.3 m/s approximately 1 km/h. The low speed was selected to ensure a high spatial resolution for the vertical scanning of the trees. The communication between the navigation software and the sensor software worked as planned. There were no occurrences of timing problems in the communication. The communication between the Server program and the client programs failed 3 times during the field trial. The data storage worked without any errors for both clients during the field trial. At the end of the field trial
the platform had driven autonomously through the orchard and collected the data.
It was possible to create a meaningful application, which could be accomplished by an autonomous platform. The protocol which was developed is scalable so it is possible to implement more sensors and actuators. Both the images and LiDAR data was collected in a satisfactory resolution and quality.