Research
Join us on Wednesdays at 9:00 AM PST when Mike Salem and Rajat Mishra host robotic paper discussions in the #research channel of udacity-robotics.slack.com Slack community.
February 14: Perception-aware Path Planning
February 7: A Computational Model of Commonsense Moral Decision Making http://moralmachine.mit.edu/
June 10: Udacity Explore's Biologically Inspired Robots Week
Abstract: WHEN IT COMES TO AUTONOMOUS ROBOTS, THE CONTRAST between fantasy and reality is really quite striking. On the one hand, we have the fantasy of such anthropomorphic robots as C3PO from Star Wars and Commander Data from Star Trek: The Next Generation which, despite their endearing quirks, negotiate complex physical and social environments with essentially the skill of a human being. On the other hand, we have the reality of industrial robots that can efficiently carry out such highly specialized tasks as painting and welding only in environments carefully constrained to minimize complications. Or, to consider a second example, we have Dante II, the semi-autonomous robot that had to be lifted out of a volcano it was exploring with a crane when it overturned. Far from being a limitation unique to the Dante II project, which should be applauded for confronting such a difficult environment, this brittleness in the face of unanticipated contingency is in fact typical of the state of the art in autonomous robotics.
Abstract: Biology is a useful tool when applied to engineering challenges that have been solved in nature. Here, the emulous goal of creating an insect-sized, truly micro air vehicle is addressed by first exploring biological principles. These principles give insights on how to generate sufficient thrust to sustain flight for centimeter-scale vehicles. Here, it is shown how novel manufacturing paradigms enable the creation of the mechanical and aeromechanical subsystems of a microrobotic device that is capable of Diptera-like wing trajectories. The results are a unique microrobot: a 60 mg robotic insect that can produce sufficient thrust to accelerate vertically. Although still externally powered, this micromechanical device represents significant progress toward the creation of autonomous insect-sized micro air vehicles.
Abstract: We present the design of a novel compliant quadruped robot: Cheetahcub, and a series of locomotion experiments with fast trotting gaits. The robot’s leg configuration is based on a spring-loaded, pantograph mechanism with multiple segments. A dedicated open loop locomotion controller was derived and implemented. Experiments were run in simulation and in hardware on flat terrain and with a step-down, demonstrating the robot’s self-stabilizing properties. The robot reached a running trot with short flight phases with a maximum Froude number of FR=1.30, or 6.9 body lengths per second. Morphological parameters such as the leg design also played a role. By adding distal in-series elasticity, self-stability and maximum robot speed improved. Our robot has several advantages, especially when compared to larger and stiffer quadruped robot designs. 1) It is, to the best of our knowledge, the fastest of all quadruped robots below 30 kg (in terms of Froude number and body lengths per second). 2) It shows self-stabilizing behavior over a large range of speeds with open loop control. 3) It is lightweight, compact, electrically powered. 4) It is cheap, easy to reproduce, robust, and safe to handle. This makes it an excellent tool for research of multi-segment legs in quadruped robots.
Abstract: RatSLAM is a navigation system based on the neural processes underlying navigation in the rodent brain, capable of operating with low resolution monocular image data. Seminal experiments using RatSLAM include mapping an entire suburb with a web camera and a long term robot delivery trial. This paper describes OpenRatSLAM, an open-source version of RatSLAM with bindings to the Robot Operating System framework to leverage advantages such as robot and sensor abstraction, networking, data playback, and visualization. OpenRatSLAM comprises connected ROS nodes to represent RatSLAM’s pose cells, experience map, and local view cells, as well as a fourth node that provides visual odometry estimates. The nodes are described with reference to the RatSLAM model and salient details of the ROS implementation such as topics, messages, parameters, class diagrams, sequence diagrams, and parameter tuning strategies. The performance of the system is demonstrated on three publicly available open-source datasets.
Abstract: The tf library was designed to provide a standard way to keep track of coordinate frames and transform data within an entire system such that individual component users can be confident that the data is in the coordinate frame that they want without requiring knowledge of all the coordinate frames in the system. During early development of the Robot Operating System (ROS), keeping track of coordinate frames was identified as a common pain point for developers. The complexity of this task made it a common place for bugs when developers improperly applied transforms to data. The problem is also a challenge due to the often distributed sources of information about transformations between different sets of coordinate frames. This paper will explain the complexity of the problem and distill the requirements. Then it will discuss the design of the tf library in relation to the requirements. A few use cases will be presented to demonstrate successful deployment of the library. And powerful extensions to the core capabilities su
Abstract: To achieve a balanced walking for a humanoid, it is necessary to estimate the dynamic stability of the system. However, in a small size humanoid with restricted system resource, it is hard to satisfy the performance level desired by dynamics analysis. Therefore, in this paper, we propose the feasible methods to generate gait pattern and stabilize walking based on coupled oscillators which have a clear correlation between oscillator parameters and system dynamics without a real time ZMP calculation. The proposed method was tested on the open humanoid platform DARwIn-OP for the evaluation, and the result showed that a real time gait pattern generation and stabilization were realized.
Abstract: This paper represents an analytical approach for solving forward kinematics problem of a serial robot manipulator with six degrees of freedom and a specific combination of joints and links to formulate the position of the gripper by a given set of joint angles. In addition, a direct geometrical solution for the robot’s inverse kinematics problem will be defined in order to calculate the robot’s joint angles to pose the gripper in a given coordinate. Furthermore, the accuracy of the two solutions will be shown by comparing the results in a developed simulation program which uses the Unified System for Automation and Robot Simulation (USARSim).
Abstract: Soft robots are primarily composed of easily deformable matter such as fluids, gels, and elastomers that match the elastic and rheological properties of biological tissue and organs. Like an octopus squeezing through a narrow opening or a caterpillar rolling through uneven terrain, a soft robot must adapt its shape and locomotion strategy for a broad range of tasks, obstacles, and environmental conditions. This emerging class of elastically soft, versatile, and biologically inspired machines represents an exciting and highly interdisciplinary paradigm in engineering that could revolutionize the role of robotics in healthcare, field exploration, and cooperative human assistance.
Abstract: Nanorobotics is an upcoming technology field of creating robots whose components are at or close to the microscopic scale of a nanometer. To be more precise, Nanorobotics is the nanotechnology technique of building and forming designs of nanorobots. These robots range in size from 0.1-10 mm and get built in nanoscale (molecular component). The names nanorobots, Nanobots, nanoids, nanites, nanomachines or Nano-mites have also been used to describe these devices currently under research and development. Nanorobots get widely employed in the research & development (R & D) phases, but some first molecular robots get tested. In an example, a sensor having switch approx 1.5 nanometers across is capable of counting specific molecules in a chemical sample. The most useful applications of Nanobots are said to be in medical technology, which is used to identify and destroy cancer cells. The other potential example is the detection of toxic chemicals, and the measurement of their concentrations, in today’s environment. The size of the Nanorobots is microscopic to be exact. Hence it is necessary for a large number of nanorobots to perform the microscopic and macroscopic tasks correctly together. These nanorobots move into large numbers i.e. swarms, both those incapable of carrying the replication and those capable of unconstrained reproduction in the natural environment.
Abstract: This work gives an overview of the broad field of computational swarm intelligence and its applications in swarm robotics. Computational swarm intelligence is modeled on the social behavior of animals and its principle application is as an optimization technique. Swarm robotics is a relatively new and rapidly developing field which draws inspiration from swarm intelligence. It is an interesting alternative to classical approaches to robotics because of some properties of problem solving present in social insects, which is flexible, robust, decentralized and self-organized. This work highlights the possibilities for further research.
Abstract: The Cloud, an infrastructure and extensive set of Internet-accessible resources, has potential to provide significant benefits to robots and automation systems. This survey is organized around four potential benefits: 1) Big Data: access to remote libraries of images, maps, trajectories, and object data, 2) Cloud Computing: access to parallel grid computing on demand for statistical analysis, learning, and motion planning, 3) Collective Robot Learning: robots sharing trajectories, control policies, and outcomes, and 4) Human Computation: use of crowdsourcing to tap human skills for analyzing images and video, classification, learning, and error recovery. The Cloud can also improve robots and automation systems by providing access to a) datasets, publications, models, benchmarks, and simulation tools, b) open competitions for designs and systems, and c) open-source software. This survey includes over 150 references on results and open challenges. A website with new developments and updates is available at: http://goldberg.berkeley.edu/cloud-robotics/
Abstract: An adoptive learning strategy using an artificial neural network ANN has been proposed here to control the motion of a 6 D.O.F manipulator robot and to overcome the inverse kinematics problem, which are mainly singularities and uncertainties in arm configurations. In this approach a network have been trained to learn a desired set of joint angles positions from a given set of end effector positions, experimental results has shown an excellent mapping over the working area of the robot, to validate the ability of the designed network to make prediction and well generalization for any set of data, a new training using different data set has been performed using the same network, experimental results has shown a good generalization for the new data sets. The proposed control technique does not require any prior knowledge of the kinematics model of the system being controlled, the basic idea of this concept is the use of the ANN to learn the characteristics of the robot system rather than to specify explicit robot system model. Any modification in the physical set-up of the robot such as the addition of a new tool would only require training for a new path without the need for any major system software modification, which is a significant advantage of using neural network technology.
April 12: Human-aware robot navigation: A survey
Abstract: Navigation is a basic skill for autonomous robots. In the last years human–robot interaction has become an important research field that spans all of the robot capabilities including perception, reasoning, learning, manipulation and navigation. For navigation, the presence of humans requires novel approaches that take into account the constraints of human comfort as well as social rules. Besides these constraints, putting robots among humans opens new interaction possibilities for robots, also for navigation tasks, such as robot guides. This paper provides a survey of existing approaches to human-aware navigation and offers a general classification scheme for the presented methods.
Abstract: With increasing demand on reliable robotic platforms that can alleviate the burden of daily painstaking tasks, researchers have focused their effort towards developing robotic platforms that possess a high level of autonomy and versatility in function. These robots, capable of operating either individually or in a group, also possess the structural modular morphology that enables them to adapt to the unstructured nature of a real environment. Over the past two decades, significant work has been published in this field, particularly in the aspects of autonomy, mobility and docking. This paper reviews the primary methods in the literature related to the fields of modular and reconfigurable mobile robotics. By bringing together aspects of modularity, including docking and autonomy, and synthesizing the most relevant findings, there is optimism that a more complete understanding of this field will serve as a starting ground for innovation and integration of such technology in the urban environment.