Autonomous navigation in complex outdoor terrains presents critical challenges for unmanned ground vehicles (UGVs) due to the inherent disconnect between global mapping and real-time sensor feedback. This work proposes a hybrid framework that integrates low-resolution Digital Elevation Model (DEM) data with real-time LiDAR-based obstacle detection and terrain analysis for efficient path planning. A global path is initially computed using a preprocessed DEM-based A* algorithm. Subsequently, local sensor data drives adaptive path correction, enabling the UGV to negotiate sudden environmental changes while maintaining safety and efficiency. Simulation results in Gazebo demonstrate significant improvements over a baseline approach, achieving a 95% obstacle avoidance rate and reducing the average encountered slope from 8∘ to 2.7∘ in custom terrain. This integration enhances path efficiency and terrain traversability and supports robust real-time adaptation, paving the way for more reliable autonomous navigation in dynamic outdoor environments.
Figures & tables
Fig. 1: Local path planning with global DEM data integration. (a) The global cost map path generated from SRTM-based elevation data. (b) Local Path Planning Region (30m) extracted from the global map for finer trajectory adjustments. (c) Rviz visualization of real-time LiDAR-based obstacle detection and path correction. (d) Gazebo simulation demonstrating the UGV avoiding obstacles in a dynamic environment (right) compared to the baseline where UGV gets stuck (left)
Fig. 2: (a) Global Processing: Acquisition of DEM data, preprocessing, and generation of the global cost map; (b) Global Path Planning: Optimal trajectory determination using A*; (c) Zoomed-in view of the global cost map, highlighting a selected region for local path refinement; (d) Local Path Correction: Integration of real-time sensor (LiDAR) data for ground segmentation, obstacle detection, and dynamic trajectory adjustment within the selected region.
Reference
OA
SE
RTS
GPO
LPR
[ 1 ]
✓
[ 14 ]
✓
✓
[ 8 ]
✓
[ 15 ]
✓
[ 5 ]
✓
✓
[ 6 ]
✓
TABLE I: Comparison of Our Approach with Related Works
Fig. 3: Visualization of ground (blue points) and non-ground (red points) segmentation from LiDAR data, along with the final path direction (green marker) as visualized in RViz. This image illustrates the result of our local path correction approach, where the UGV dynamically adjusts its trajectory to avoid nearby obstacles and maintain safe navigation through complex terrains.
θcurrent←arccos(∥n∥∥z∥n⋅z)
Algorithm 1 Slope Estimation and Adaptive Traversability Analysis
Fig. 4: Height distribution from terrain in Figure 4(c) as observed by the UGV. The blue histogram shows that most obstacle heights cluster near –0.50 m, with a right tail extending into positive values. The green dashed line indicates the median (–0.45 m) and the red dashed line shows the mean (–0.30 m), confirming a right-skewed distribution ( S>0 ).
Fig. 5: (a) UGV navigating a flat terrain while detecting and avoiding an obstacle (here a pit). The trajectory taken by the UGV is indicated with the blue arrow avoiding the obstacle in its view. (b) UGV traversing a rugged landscape with visible obstacles (pits). The illustration highlights adaptive path planning and obstacle avoidance using our algorithm in action on rough terrain. (c) UGV navigating over a slope, illustrating its capability to handle inclines. The figure depicts how using our algorithm, UGV detects the bump and the adjustments made to avoid and maintain stability.
Fig. 6: Side-by-side comparison of the real Compusult Ltd.’s Nanuk UGV (left) and its ROS model derived from the URDF file (right). This comparison demonstrates the fidelity of our simulation model for sensor integration and navigation evaluation.
Metric
Our Approach
Baseline
Non-Rough
Obstacle
Non-Rough
Obstacle
Avoidance Rate (%)
95
0
Average Slope (°)
0.7
2.7
0.7
8
Time to Goal (s)
43
77
43
Stuck
Path Deviation (m)
0
4.25
0
Stuck
TABLE II: Performance comparison of our approach versus the baseline under varying terrain conditions. NB:* — Not applicable
Autonomous driving in off-road environments presents significant challenges due to the dynamic and unpredictable nature of unstructured terrain. Traditional kinodynamic models often struggle to generalize across diverse geometric and semantic terrain types, underscoring the need for real-time adaptation to ensure safe and reliable navigation. We propose VertiAdaptor (VA), a novel online adaptation framework that efficiently integrates elevation with semantic embeddings to enable terrain-aware kinodynamic modeling and planning via function encoders. VA learns a kinodynamic space spanned by a set of neural ordinary differential equation basis functions, capturing complex vehicle-terrain interactions across varied environments. After offline training, the proposed approach can rapidly adapt to new, unseen environments by identifying kinodynamics in the learned space through a computationally efficient least-squares calculation. We evaluate VA within the Verti-Bench simulator, built on the Chrono multi-physics engine, and validate its performance both in simulation and on a physical Verti-4-Wheeler platform. Our results demonstrate that VA improves prediction accuracy by up to 23.9% and achieves a 5X faster adaptation time, advancing the robustness and reliability of autonomous robots in complex and evolving off-road environments.
Tong Xu, Chenhui Pan, Aniket Datar +1
Department of Computer Science, George Mason University
This paper presents a collaborative UAV-UGV navigation framework for high-altitude, snow-covered terrain, where reduced visibility and unstable ground render conventional methods ineffective. We introduce a custom efficient U-Net architecture that falls under the computational constraints for real-time road segmentation, utilizing a novel synthetic snow data augmentation technique to achieve 96.5% segmentation accuracy. For UAV localization, we implement an Extended Kalman Filter (EKF) fusing onboard GPS and IMU data, achieving a maximum observed positional error of +-0.5 meters. The UGV position is determined via a visual tracking pipeline using YOLOv5 and depth data from the UAV's RGB-D camera. A dynamic path planning algorithm utilizes this segmentation to adjust for snow drifts, enabling successful navigation in obscured test environment with minimal deviation.
Shreyam Gupta, P. Agrawal, Priyam Gupta +1
Robotics Research Group, Indian Institute of Technology · Robotics Research Group, Indian Institute of Technology (BHU), Varanasi, India · University of Colorado, Boulder, USA +2
Navigating autonomous underwater vehicles (AUVs) in unknown environments is significantly challenging due to poor visibility, weak signal transmission, and dynamic water currents. These factors pose challenges in accurate global localization, reliable communication, and obstacle avoidance. Local sensing provides critical real time environmental data to enable online decision making. However, the inherent noise in underwater sensor measurements introduces uncertainty, complicating planning and control. To address these challenges, we propose an integrated planning and control framework that leverages real time sensor data to dynamically induce closed loop AUV trajectories, ensuring robust obstacle avoidance and enhanced maneuverability in tight spaces. By planning motion based on pre designed feedback controllers, the approach reduces the computational complexity needed for carrying out online optimizations and enhances operational safety in complex underwater spaces. The proposed method is validated through ROS Gazebo simulations on the RexRov AUV, demonstrating its efficacy. Its performance is evaluated by comparison against PID based tracking methods, and quantifying localization errors in dead reckoning as the AUV transitions into the target communication range.
Veejay Karthik, Udit Ekansh, Tejal Bedmutha +3
Centre for Systems and Control, Indian Institute of Technology Bombay, Mumbai · Institute for Control, Optimization, and Networks, Purdue University, West Lafayette, USA