Camera rotation estimation from a single image is a challenging task, often requiring depth data and/or camera intrinsics, which are generally not available for in-the-wild videos. Although external sensors such as inertial measurement units (IMUs) can help, they often suffer from drift and are not applicable in non-inertial reference frames. We present U-ARE-ME, an algorithm that estimates camera rotation along with uncertainty from uncalibrated RGB images. Using a Manhattan World assumption, our method leverages the per-pixel geometric priors encoded in single-image surface normal predictions and performs optimisation over the SOC 3) manifold. Given a sequence of images, we can use the per-frame rotation estimates and their uncertainty to perform multi-frame optimisation, achieving robustness and temporal consistency. Our experiments demonstrate that U-ARE-ME performs comparably to RGB-D methods and is more robust than feature-based vanishing point and SLAM methods.

Robotic gas distribution mapping improves the understanding of a hazardous gas dispersion while putting the human operator out of danger. Generating an accurate gas distribution map quickly is of utmost importance in situations such as gas leaks and industrial incidents, so that the efficient use of resources in response to incidents can be facilitated. In this paper, to incorporate the operational requirement on map granularity, we propose a low-to-high resolution path planner that first guides a single robots to quickly and sparsely sample the region of interest to generate a low resolution gas distribution map, followed by high resolution sampling informed by the low resolution map as a prior. The low resolution prior acts as a coverage survey allowing the algorithm to perform a relatively exploitative search of high concentration regions, resulting in overall shorter mission times. The proposed framework is designed to iteratively identify the next best T locations to sample, which prioritises the potentially high reward locations, while ensuring that the robot can travel to and sample the chosen locations within a user specified map update cycle. We present a simulation study to demonstrate the alternating exploration-exploitation like behaviour along with bench-marking its performance in contrast to the traditional sampling path planners and various reward functions.

This paper proposes a new 3D gas distribution mapping technique based on Gaussian belief propagation, which is capable of resolving in real time, the concentration estimates in 3D space whilst accounting for the obstacle information within the scenario, the first of its kind in the literature. The gas mapping problem is formulated as a 3D factor graph of Gaussian potentials, the connections of which are conditioned on local occupancy values. The Gaussian belief propagation framework is introduced as the solver and a new hybrid message scheduler is introduced to increase the rate of convergence. The factor graph problem is then redesigned as a dynamically expanding inference task, coupling the information of consecutive gas measurements with local spatial structure obtained by the robot. The proposed algorithm is compared to the state of the art methods in 2D and 3D simulations and is found to resolve distribution maps orders of magnitude quicker than typical direct solvers. The proposed framework is then deployed onboard a ground robot in a 3D mapping and exploration task. The system is shown to be able to resolve multiple sensor inputs and output high resolution 3D gas distribution maps in a GPS denied cluttered scenario in real time. This online inference of complicated gas dispersion provides a new layer of contextual information over its 2D counterparts and enables autonomous systems to take advantage of real time estimates to inform potential next best sampling locations.Note to Practitioners—The motivation of this work arises from the need to develop the robotic gas distribution mapping capability that can provide real-time situational awareness of the scenarios. The output distribution maps can be used to inform human first responders as to what areas of the environment contain a hazard, but looking towards autonomous robots, they can also be used by the robot itself to inform where should be measured next to gather more information about the environment. When performing these mapping tasks in unknown indoor environments, it is very important that the sensing robot can build up the knowledge of its physical surroundings together with how the obstacles in the environment affect the 3D gas distribution. The Gaussian belief propagation algorithm allows us to achieve all of this in real-time onboard the sensing robot, something that is yet to be achieved in the literature.

This paper advocates the Gaussian belief propagation solver for factor graphs in the case of gas distribution mapping to support an olfactory sensing robot. The local message passing of belief propagation moves away from the standard Cholesky decomposition technique, which avoids solving the entire factor graph at once and allows for only areas of interest to be updated more effectively. Implementing a local solver means that iterative updates to the distribution map can be achieved orders of magnitude quicker than conventional direct solvers which scale computationally to the size of the map. After defining the belief propagation algorithm for gas mapping, several state of the art message scheduling algorithms are tested in simulation against the standard Cholesky solver for their ability to converge to the exact solution. Testing shows that under the wildfire scheduling method for a large urban scenario, that distribution maps can be iterated at least 10 times faster whilst still maintaining exact solutions. This move to an efficient local framework allows future works to consider 3D mapping, predictive utility and multi-robot distributed mapping.

Mobile robotic gas distribution mapping (GDM) is a useful tool for hazardous scene assessment where a quick and accurate representation of gas concentration levels is required throughout a staging area. However, research in robotic path planning for GDM has primarily focused on mapping in open spaces or estimating the source term in dispersion models. Whilst this may be appropriate for environment monitoring in general, the vast majority of GDM applications involve obstacles, and path planning for autonomous robots must account for this. This paper aims to tackle this challenge by integrating a GDM function with an informative path planning framework. Several GDM methods are explored for their suitability in cluttered environments and the GMRF method is chosen due to its ability to account for obstacle interactions within the plume. Based on the outputs of the GMRF, several reward functions are proposed for the informative path planner. These functions are compared to a lawnmower sweep in a high fidelity simulation, where the RMSE of the modelled gas distribution is recorded over time. It is found that informing the robot with uncertainty, normalised concentration and time cost, significantly reduces the time required for a single robot to achieve an accurate map in a large-scale, urban environment. In the context of a hazardous gas release scenario, this time reduction could save lives as well as further gas ingress.