In agriculture, technological advances have given automation and robotics a significant boost. The main objective of implementing robots is to perform monotonous tasks that take up most of the time. The most significant advantage in the cultivation of agricultural land represent mobile systems, which, with the right design, have an unlimited range of operation.
The master thesis covers the design and development of a mobile platform for use in a greenhouse. The work started with a review of existing technologies and robotic systems designed for greenhouse operations. After the review of the technologies, we examined the existing wheeled systems. We selected the differential drive for its ability to move between plant rows and central parts of the greenhouse. For this purpose, we assembled a drive and omnidirectional wheels with additional 3D-printed rims and machined axles.
The design and development of the chassis were followed by the design and construction of the mobile platform in modelling software. The frame was assembled from aluminium profiles based on the 3D model.
We defined the power requirements of the hardware used and selected the appropriate components for the battery assembly. The connections were drawn using an electrical schematic drawing program and implemented. All components were fixed and enclosed in an aluminium housing.
For the drive, we used two servo motors from Beckhoff, low-power controlled with the TwinCAT software environment and a programmable logic controller. We performed kinematics and odometry calculations, which were used to control the platform. We loaded a high-level robotic operating system on the computer, where we programmed the nodes to allow remote control of the platform and its autonomous driving.
Using laser sensors from SICK, we implemented safety in the operation of the mobile platform. We processed the received data and used their values to limit the movements of the platform in the greenhouse. We additionally used the sensors to detect the end of the row in the greenhouse.
We tested the operation of the mobile platform by mounting cameras in the greenhouse and confirmed that it was working as expected.
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