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A Haptic-Based Proximity Sensing System for Buried Object in Granular Material

arXiv.org Artificial Intelligence

The proximity perception of objects in granular materials is significant, especially for applications like minesweeping. However, due to particles' opacity and complex properties, existing proximity sensors suffer from high costs from sophisticated hardware and high user-cost from unintuitive results. In this paper, we propose a simple yet effective proximity sensing system for underground stuff based on the haptic feedback of the sensor-granules interaction. We study and employ the unique characteristic of particles -- failure wedge zone, and combine the machine learning method -- Gaussian process regression, to identify the force signal changes induced by the proximity of objects, so as to achieve near-field perception. Furthermore, we design a novel trajectory to control the probe searching in granules for a wide range of perception. Also, our proximity sensing system can adaptively determine optimal parameters for robustness operation in different particles. Experiments demonstrate our system can perceive underground objects over 0.5 to 7 cm in advance among various materials.


Robo-Insight #4

Robohub

Source: OpenAI's DALLยทE 2 with prompt "a hyperrealistic picture of a robot reading the news on a laptop at a coffee shop" Welcome to the 4th edition of Robo-Insight, a biweekly robotics news update! In this post, we are excited to share a range of new advancements in the field and highlight robots' progress in areas like mobile applications, cleaning, underwater mining, flexibility, human well-being, depression treatments, and human interactions. In the world of system adaptions, researchers from Eindhoven University of Technology have introduced a methodology that bridges the gap between application developers and control engineers in the context of mobile robots' behavior adaptation. This approach leverages symbolic descriptions of robots' behavior, known as "behavior semantics," and translates them into control actions through a "semantic map." This innovation aims to simplify motion control programming for autonomous mobile robot applications and facilitate integration across various vendors' control software.


Forecasting of the development of a partially-observed dynamical time series with the aid of time-invariance and linearity

arXiv.org Artificial Intelligence

Notwithstanding its difficulty, forecasting of the development of intricate non-linear dynamical systems has been in a spotlight of various scientific fields (Strogatz, 2001; Jackson and Radunskaya, 2015). A plausible approach to forecasting the development is to isolate the non-linear estimation problem into (i) learning non-linear representations by applying highly non-linear functions such as deep neural networks (Goodfellow et al., 2016), and (ii) estimating its development with simple linear models. An example is a reservoir computing (RC; Jaeger, 2001, 2002). RC first randomly specifies a state in the reservoir layer in recurrent neural network (Rumelhart et al., 1986), and optimizes the weights only in the output layer; RC corresponds to non-linearly transform its input (in the reservoir layer) and trains a simple linear prediction model (in the output layer). It has been reported that such a simple combination of the non-linear representation learning and the linear estimation is effective to forecasting the intricate dynamical systems (Tanaka et al., 2019). Effectiveness of the simple combination is not limited to RC; applying a linear model to the non-linear representation in more general deep neural network is also regarded as a solid forecasting strategy (Lusch et al., 2018). Unfortunately, however, partial degrees of freedom corresponding to several state variables are not observed in some practical situations (Lucor et al., 2022; Cheng et al., 2023). There could be a variety of reasons for missing observations: it would be caused by the difficulty of measurement, it would be caused by the immature understanding of the system of interest, and so forth.


Advances in apparent conceptual physics reasoning in GPT-4

arXiv.org Artificial Intelligence

ChatGPT is built on a large language model trained on an enormous corpus of human text to emulate human conversation. Despite lacking any explicit programming regarding the laws of physics, recent work has demonstrated that GPT-3.5 could pass an introductory physics course at some nominal level and register something close to a minimal understanding of Newtonian Mechanics on the Force Concept Inventory. This work replicates those results and also demonstrates that the latest version, GPT-4, has reached a much higher mark in the latter context. Indeed, its responses come quite close to perfectly demonstrating expert-level competence, with a few very notable exceptions and limitations. We briefly comment on the implications of this for the future of physics education and pedagogy.


Sensing and Navigation of Aerial Robot for Measuring Tree Location and Size in Forest Environment

arXiv.org Artificial Intelligence

This paper shows the achievement of a sensing and navigation system of aerial robot for measuring location and size of trees in a forest environment autonomously. Although forestry is an important industry in Japan, the working population of forestry is decreasing. Then, as an application of mechanization of forestry, we propose tree data collection system by aerial robots which have high mobility in three-dimensional space. First, we develop tree recognition and measurement method, along with algorithm to generate tree database. Second, we describe aerial robot navigation system based on tree recognition. Finally, we present an experimental result in which an aerial robot flies in a forest and collects tree data.


Wobble control of a pendulum actuated spherical robot

arXiv.org Artificial Intelligence

Spherical robots can conduct surveillance in hostile, cluttered environments without being damaged, as their protective shell can safely house sensors such as cameras. However, lateral oscillations, also known as wobble, occur when these sphere-shaped robots operate at low speeds, leading to shaky camera feedback. These oscillations in a pendulum-actuated spherical robot are caused by the coupling between the forward and steering motions due to nonholonomic constraints. Designing a controller to limit wobbling in these robots is challenging due to their underactuated nature. We propose a model-based controller to navigate a pendulum-actuated spherical robot using wobble-free turning maneuvers consisting of circular arcs and straight lines. The model is developed using Lagrange-D'Alembert equations and accounts for the coupled forward and steering motions. The model is further analyzed to derive expressions for radius of curvature, precession rate, wobble amplitude, and wobble frequency during circular motions. Finally, we design an input-output feedback linearization-based controller to control the robot's heading direction and wobble. Overall, the proposed controller enables a teleoperator to command a specific forward velocity and pendulum angle as per the desired turning radius while limiting the robot's lateral oscillations to enhance the quality of camera feedback.


Bounded Distance-control for Multi-UAV Formation Safety and Preservation in Target-tracking Applications

arXiv.org Artificial Intelligence

The notion of safety in multi-agent systems assumes great significance in many emerging collaborative multi-robot applications. In this paper, we present a multi-UAV collaborative target-tracking application by defining bounded inter-UAV distances in the formation in order to ensure safe operation. In doing so, we address the problem of prioritizing specific objectives over others in a multi-objective control framework. We propose a barrier Lyapunov function-based distributed control law to enforce the bounds on the distances and assess its Lyapunov stability using a kinematic model. The theoretical analysis is supported by numerical results, which account for measurement noise and moving targets. Straight-line and circular motion of the target are considered, and results for quadratic Lyapunov function-based control, often used in multi-agent multi-objective problems, are also presented. A comparison of the two control approaches elucidates the advantages of our proposed safe-control in bounding the inter-agent distances in a formation. A concluding evaluation using ROS simulations illustrates the practical applicability of the proposed control to a pair of multi-rotors visually estimating and maintaining their mutual separation within specified bounds, as they track a moving target.


Smart Edge Cam with Gesture Alarm

#artificialintelligence

Gesture Triggered Alarm for Security based on CV, Vector Concavity Estimation, OpenVINO, MQTT, and Pimoroni Blinkt on RPi or Jetson Nano. Notwithstanding notable advancements in technology, the developing economies are still trapped in the clutches of patriarchal evils like molestation, rape, or crime against women, in general. Women are often not allowed to stay back in their professional workspaces during late hours, nor are considered safe alone even during day time, especially in the developing world. Imperative, it has become, to enable the other half of population to be more safe & productive. Why not use advancements in technology to arm them with more power?


A Functional Architecture for Motion Pattern Processing in MSTd

Neural Information Processing Systems

Psychophysical studies suggest the existence of specialized detectors for component motion patterns (radial, circular, and spiral), that are consistent with the visual motion properties of cells in the dorsal medial superior temporal area (MSTd) of nonhuman primates. Here we use a biologically constrained model of visual motion processing in MSTd, in conjunction with psychophysical performance on two motion pattern tasks, to elucidate the computational mechanisms associated with the processing of widefield motionpatterns encountered during self-motion. In both tasks discrimination thresholds varied significantly with the type of motion pattern presented, suggesting perceptual correlates to the preferred motion bias reported in MSTd. Through the model we demonstrate that while independently responding motion pattern units are capable of encoding information relevant to the visual motion tasks, equivalent psychophysical performance can only be achieved using interconnected neural populations that systematically inhibit non-responsive units. These results suggest the cyclic trends in psychophysical performance may be mediated, in part, by recurrent connections within motion pattern responsive areas whose structure is a function of the similarity in preferred motion patterns and receptive field locations between units.


A Functional Architecture for Motion Pattern Processing in MSTd

Neural Information Processing Systems

Psychophysical studies suggest the existence of specialized detectors for component motion patterns (radial, circular, and spiral), that are consistent with the visual motion properties of cells in the dorsal medial superior temporal area (MSTd) of nonhuman primates. Here we use a biologically constrained model of visual motion processing in MSTd, in conjunction with psychophysical performance on two motion pattern tasks, to elucidate the computational mechanisms associated with the processing of widefield motion patterns encountered during self-motion. In both tasks discrimination thresholds varied significantly with the type of motion pattern presented, suggesting perceptual correlates to the preferred motion bias reported in MSTd. Through the model we demonstrate that while independently responding motion pattern units are capable of encoding information relevant to the visual motion tasks, equivalent psychophysical performance can only be achieved using interconnected neural populations that systematically inhibit non-responsive units. These results suggest the cyclic trends in psychophysical performance may be mediated, in part, by recurrent connections within motion pattern responsive areas whose structure is a function of the similarity in preferred motion patterns and receptive field locations between units.