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Christopher F. Lehnert

9 accepted papers

2025

QueryAdapter: Rapid Adaptation of Vision-Language Models in Response to Natural Language Queries

IROS 2025

A domain shift exists between the large-scale, internet data used to train a Vision-Language Model (VLM) and the raw image streams collected by a robot. Existing adaptation strategies require the definition of a closed-set of classes, which is impractical for a robot that must respond to diverse nat

Cited by 1SourceScholar
2023

Predicting Class Distribution Shift for Reliable Domain Adaptive Object Detection

RA-L 2023

Unsupervised Domain Adaptive Object Detection (UDA-OD) uses unlabelled data to improve the reliability of robotic vision systems in open-world environments. Previous approaches to UDA-OD based on self-training have been effective in overcoming changes in the general appearance of images. However, sh

Cited by 11SourcecodeScholar
2018

Efficacy of Mechanical Weeding Tools: A Study Into Alternative Weed Management Strategies Enabled by Robotics

RA-L 2018

The rise of herbicide resistant weed species has reinvigorated research in nonchemical methods for weed management. Robots, such as AgBot II, that can detect and classify weeds as they traverse a field are a key enabling factor for individualised treatment of weed species. Integral to the invidualiz

Cited by 61SourceScholar
2017

Autonomous Sweet Pepper Harvesting for Protected Cropping Systems

RA-L 2017

In this letter, we present a new robotic harvester (Harvey) that can autonomously harvest sweet pepper in protected cropping environments. Our approach combines effective vision algorithms with a novel end-effector design to enable successful harvesting of sweet peppers. Initial field trials in prot

Cited by 229SourceScholar
2017

Peduncle Detection of Sweet Pepper for Autonomous Crop Harvesting - Combined Color and 3-D Information

RA-L 2017

This letter presents a three-dimensional (3-D) visual detection method for the challenging task of detecting peduncles of sweet peppers (Capsicum annuum) in the field. Cutting the peduncle cleanly is one of the most difficult stages of the harvesting process, where the peduncle is the part of the cr

Cited by 124SourceScholar
2017

Teaching Robots Generalizable Hierarchical Tasks Through Natural Language Instruction

RA-L 2017

Natural language provides a convenient means of communicating information, and as such, is an ideal medium for enabling nonexpert users to teach robots novel tasks. However, in order to take advantage of natural language, a series of challenges must first be overcome. These challenges include the ne

Cited by 15SourceScholar
2016

Sweet pepper pose detection and grasping for automated crop harvesting

ICRA 2016

This paper presents a method for estimating the 6DOF pose of sweet-pepper (capsicum) crops for autonomous harvesting via a robotic manipulator. The method uses the Kinect Fusion algorithm to robustly fuse RGB-D data from an eye-in-hand camera combined with a colour segmentation and clustering step t

Cited by 90SourceScholar
2016

Visual detection of occluded crop: For automated harvesting

ICRA 2016

This paper presents a novel crop detection system applied to the challenging task of field sweet pepper (capsicum) detection. The field-grown sweet pepper crop presents several challenges for robotic systems such as the high degree of occlusion and the fact that the crop can have a similar colour to

Cited by 77SourceScholar