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Semantic Landmark Particle Filter for Robot Localisation in Vineyards

Rajitha de Silva, Jonathan Cox, James R. Heselden, Marija Popović, Cesar Cadena, Riccardo Polvara

TL;DR

A Semantic Landmark Particle Filter (SLPF) is presented that integrates trunk and pole landmark detections with 2D LiDAR within a probabilistic localisation framework and enables robust localisation in highly repetitive outdoor agricultural environments.

Abstract

Reliable localisation in vineyards is hindered by row-level perceptual aliasing: parallel crop rows produce nearly identical LiDAR observations, causing geometry-only and vision-based SLAM systems to converge towards incorrect corridors, particularly during headland transitions. We present a Semantic Landmark Particle Filter (SLPF) that integrates trunk and pole landmark detections with 2D LiDAR within a probabilistic localisation framework. Detected trunks are converted into semantic walls, forming structural row boundaries embedded in the measurement model to improve discrimination between adjacent rows. GNSS is incorporated as a lightweight prior that stabilises localisation when semantic observations are sparse. Field experiments in a 10-row vineyard demonstrate consistent improvements over geometry-only (AMCL), vision-based (RTAB-Map), and GNSS baselines. Compared to AMCL, SLPF reduces Absolute Pose Error by 22% and 65% across two traversal directions; relative to a NoisyGNSS baseline, APE decreases by 65% and 61%. Row correctness improves from 0.67 to 0.73, while mean cross-track error decreases from 1.40 m to 1.26 m. These results show that embedding row-level structural semantics within the measurement model enables robust localisation in highly repetitive outdoor agricultural environments.

Semantic Landmark Particle Filter for Robot Localisation in Vineyards

TL;DR

A Semantic Landmark Particle Filter (SLPF) is presented that integrates trunk and pole landmark detections with 2D LiDAR within a probabilistic localisation framework and enables robust localisation in highly repetitive outdoor agricultural environments.

Abstract

Reliable localisation in vineyards is hindered by row-level perceptual aliasing: parallel crop rows produce nearly identical LiDAR observations, causing geometry-only and vision-based SLAM systems to converge towards incorrect corridors, particularly during headland transitions. We present a Semantic Landmark Particle Filter (SLPF) that integrates trunk and pole landmark detections with 2D LiDAR within a probabilistic localisation framework. Detected trunks are converted into semantic walls, forming structural row boundaries embedded in the measurement model to improve discrimination between adjacent rows. GNSS is incorporated as a lightweight prior that stabilises localisation when semantic observations are sparse. Field experiments in a 10-row vineyard demonstrate consistent improvements over geometry-only (AMCL), vision-based (RTAB-Map), and GNSS baselines. Compared to AMCL, SLPF reduces Absolute Pose Error by 22% and 65% across two traversal directions; relative to a NoisyGNSS baseline, APE decreases by 65% and 61%. Row correctness improves from 0.67 to 0.73, while mean cross-track error decreases from 1.40 m to 1.26 m. These results show that embedding row-level structural semantics within the measurement model enables robust localisation in highly repetitive outdoor agricultural environments.
Paper Structure (31 sections, 14 equations, 5 figures, 3 tables)

This paper contains 31 sections, 14 equations, 5 figures, 3 tables.

Figures (5)

  • Figure 1: Vineyard semantics detection (left) projected onto the landmark map (right) for likelihood calculation. Green: vine trunks, Blue: support poles.
  • Figure 2: Vineyard structural map with RTK-GNSS ground-truth traverses for the two experiments. Orange circles and green squares indicate row posts and vines, while orange and green line segments denote pole- and trunk-based semantic walls. Red (Experiment 1) and blue (Experiment 2) trajectories are the RTK paths; start/end markers indicate traversal direction.
  • Figure 3: Overview of the Semantic Particle Filter. Instance masks from segmentation are combined with depth to generate BEV projections of vineyard landmarks. These projections label near-field LiDAR returns as semantic observations for the particle filter, augmented with a NoisyGNSS prior.
  • Figure 4: Raw Absolute Pose Error (APE) trajectories comparing SLPF (ours), AMCL+NoisyGNSS (Kalman fusion), RTAB-Map RGBD, and NoisyGNSS (subsampled to facilitate visualisation). The dashed black line is ground truth; coloured paths show method deviations.
  • Figure 5: Zoomed comparison during a headland transition (Experiment 1). AMCL+NoisyGNSS remains aligned to an adjacent row despite locally smooth tracking, while SLPF recovers through semantic wall constraints and adaptive GNSS weighting.