Image-based ground distance detection for crop-residue-covered soil

TL;DR

This paper introduces an image-based method using 3D and RGB cameras to accurately measure ground distance in crop-residue-covered soil, enabling precise agricultural operations despite residue interference.

Contribution

It presents a novel approach combining depth and color images to distinguish soil from residues for accurate ground distance measurement in conservation agriculture.

Findings

Measurement error within ±3mm

Feasible for real-time implementation

Applicable to precision seeding and other depth-control tasks

Abstract

Conservation agriculture features a soil surface covered with crop residues, which brings benefits of improving soil health and saving water. However, one significant challenge in conservation agriculture lies in precisely controlling the seeding depth on the soil covered with crop residues. This is constrained by the lack of ground distance information, since current distance measurement techniques, like laser, ultrasonic, or mechanical displacement sensors, are incapable of differentiating whether the distance information comes from the residue or the soil. This paper presents an image-based method to get the ground distance information for the crop-residues-covered soil. This method is performed with 3D camera and RGB camera, obtaining depth image and color image at the same time. The color image is used to distinguish the different areas of residues and soil and finally generates a mask image. The mask image is applied to the depth image so that only the soil area depth information can be used to calculate the ground distance, and residue areas can be recognized and excluded from ground distance detection. Experimentation shows that this distance measurement method is feasible for real-time implementation, and the measurement error is within plus or minus 3mm. It can be applied in conservation agriculture machinery for precision depth seeding, as well as other depth-control-demanding applications like transplant or tillage.