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This paper explores the idea of reducing a robot's energy consumption while following a trajectory by turning off the main localisation subsystem and switching to a lowerpowered, less accurate odometry source at appropriate times. This applies to scenarios where the robot is permitted to deviate from the original trajectory, which allows for energy savings. Sensor scheduling is formulated as a probabilistic belief planning problem. Two algorithms are presented which generate feasible perception schedules: the first is based upon a simple heuristic; the second leverages dynamic programming to obtain optimal plans. Both simulations and real-world experiments on a planetary rover prototype demonstrate over 50% savings in perception-related energy, which translates into a 12% reduction in total energy consumption. I. INTRODUCTIONRobots require energy to operate. Yet they only have access to limited energy storage during missions. As we extend the reach of autonomous systems to operate in remote locations, over long distances and for long periods of time, energy considerations are becoming increasingly important. To date, these considerations are often brought to bear in schemes where trajectories or speed profiles are optimised to minimise the energy required for actuation (see, for example, [1], [2], [3]). Here we take a different, yet complementary, approach in considering the energy expenditure for sensing (and, implicitly, computation) associated with navigation. In particular, our goal is to activate the perception system only as required to maintain the vehicle within a given margin around a predetermined path. As the main navigation sensors are switched off and the robot reverts to a lower-powered, less accurate odometry source for parts of the trajectory, any associated computation will also be reduced, leading to further savings in energy.Naively, such perception schedules could be constructed by switching sensors on and off randomly or according to, for example, a fixed frequency. This does, however, suffer the drawback that no heed is paid to drift in the robot's position with respect to the original trajectory: it may not be desirable to deviate by more than an allowed margin from the predetermined route. This arises, for example, in a planetary exploration scenario when conducting long traverses over featureless terrain. Other possible considerations include traversability, obstacles, and the robustness of the localisation system to deviations from the original path. Such naive approaches would also need to be tuned to individual trajectories as savings would depend significantly on trajectory shape. In this work we present two approaches which explicitly account for drift and trajectory shape (though the

Hand-crafting generalised decision-making rules for real-world urban autonomous driving is hard. Alternatively, learning behaviour from easy-to-collect human driving demonstrations is appealing. Prior work has studied imitation learning (IL) for autonomous driving with a number of limitations. Examples include only performing lane-following rather than following a user-defined route, only using a single camera view or heavily cropped frames lacking state observability, only lateral (steering) control, but not longitudinal (speed) control and a lack of interaction with traffic. Importantly, the majority of such systems have been primarily evaluated in simulation -a simple domain, which lacks real-world complexities. Motivated by these challenges, we focus on learning representations of semantics, geometry and motion with computer vision for IL from human driving demonstrations. As our main contribution, we present an end-to-end conditional imitation learning approach, combining both lateral and longitudinal control on a real vehicle for following urban routes with simple traffic. We address inherent dataset bias by data balancing, training our final policy on approximately 30 hours of demonstrations gathered over six months. We evaluate our method on an autonomous vehicle by driving 35km of novel routes in European urban streets.

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Abstract-In this paper, we consider the problem of Lifelong Robotic Object Discovery (LROD) as the long-term goal of discovering novel objects in the environment while the robot operates, for as long as the robot operates. As a first step towards LROD, we automatically process the raw video stream of an entire workday of a robotic agent to discover objects.We claim that the key to achieve this goal is to incorporate domain knowledge whenever available, in order to detect and adapt to changes in the environment. We propose a general graph-based formulation for LROD in which generic domain knowledge is encoded as constraints. Our formulation enables new sources of domain knowledge-metadata-to be added dynamically to the system, as they become available or as conditions change. By adding domain knowledge, we discover 2.7× more objects and decrease processing time 190 times. Our optimized implementation, HerbDisc, processes 6 h 20 min of RGBD video of real human environments in 18 min 30 s, and discovers 121 correct novel objects with their 3D models. I. INTRODUCTIONWe focus on the problem of Lifelong Robotic Object Discovery (LROD): discovering new objects unsupervised in an environment while the robot operates, for as long as the robot operates. Key challenges in LROD are scalability to massive datasets, robustness in dynamic human environments, and adaptability to different conditions over time. As a first step towards LROD, we address these challenges on an entire workday of data, collected as our robot explored a cluttered and populated office building. We show for the first time a system that processes, in under 19 minutes, hundreds of thousands of samples and over 6 h of continous exploration, to discover over a hundred new objects in cluttered human environments.Our key insight to making LROD feasible is to incorporate domain knowledge. More precisely, the data gathered by a service robot is not an unordered collection of anonymous images: range data is also available; we may know where and/or when the images are captured, as well as their ordering; we may know where interesting objects usually appear for a particular environment, such as in tables or cabinets; we may have additional sensing (e.g., robot localization, odometry) for some or all the images; or we may only be interested in objects of certain sizes or shapes relevant to the robot. In our work, we define the term metadata to encode any source of domain knowledge. Our definition includes any additional robotic sensing, assumptions, or prior information; in short, any non-visual data that can provide information about the object candidates.Prior work in robotics has widely used metadata to limit computational costs and improve robustness in perception. The metadata is mostly incorporated by imposing restrictions on the environment, data acquisition, or agent motion, which

Energy consumption represents one of the most basic constraints for mobile robot autonomy. We propose a new framework to predict energy consumption using information extracted from publicly available maps. This method avoids having to model internal robot configurations, which are often unavailable, while still providing invaluable predictions for both explored and unexplored trajectories. Our approach uses a heteroscedastic Gaussian Process to model the power consumption, which explicitly accounts for variance due to exogenous latent factors such as traffic and weather conditions. We evaluate our framework on 30km of data collected from a city centre environment with a mobile robot travelling on pedestrian walkways. Results across five different test routes show an average difference between predicted and measured power consumption of 3.3%, leading to an average error of 6.6% on predictions of energy consumption. The distinct advantage of our model is our ability to predict measurement variance. The variance predictions improved by 84.3% over a benchmark.

Despite significant advances in machine learning and perception over the past few decades, perception algorithms can still be unreliable when deployed in challenging time-varying environments. When these systems are used for autonomous decision-making, such as in self-driving vehicles, the impact of their mistakes can be catastrophic. As such, it is important to characterize the performance of the system and predict when and where it may fail in order to take appropriate action. While similar in spirit to the idea of introspection, this work introduces a new paradigm for predicting the likely performance of a robot's perception system based on past experience in the same workspace. In particular, we propose two models that probabilistically predict perception performance from observations gathered over time. While both approaches are place-specific, the second approach additionally considers appearance similarity when incorporating past observations. We evaluate our method in a classical decision-making scenario in which the robot must choose when and where to drive autonomously in 60 km of driving data from an urban environment. Results demonstrate that both approaches lead to fewer false decisions (in terms of incorrectly offering or denying autonomy) for two different detector models, and show that leveraging visual appearance within a state-of-the-art navigation framework increases the accuracy of our performance predictions.