Both, robot and hand-eye calibration haven been object to research for decades. While current approaches manage to precisely and robustly identify the parameters of a robot's kinematic model, they still rely on external devices, such as calibration objects, markers and/or external sensors. Instead of trying to fit the recorded measurements to a model of a known object, this paper treats robot calibration as an offline SLAM problem, where scanning poses are linked to a fixed point in space by a moving kinematic chain. As such, the presented framework allows robot calibration using nothing but an arbitrary eye-in-hand depth sensor, thus enabling fully autonomous self-calibration without any external tools. My new approach is utilizes a modified version of the Iterative Closest Point algorithm to run bundle adjustment on multiple 3D recordings estimating the optimal parameters of the kinematic model. A detailed evaluation of the system is shown on a real robot with various attached 3D sensors. The presented results show that the system reaches precision comparable to a dedicated external tracking system at a fraction of its cost.
Accurate Calibration and Robust LiDAR-Inertial Odometry for Spinning Actuated LiDAR Systems
Engineering Research Center of Low-Altitude Perception and Detection Technology & Intelligent IoT, Ministry of Education, School of Automation, Guangdong University of Technology（低空感知与探测技术及智能物联网工程研究中心，教育部，自动化学院，广东工业大学）；School of Electrical and Electronic Engineering, Nanyang Technological University（电子与电气工程学院，南洋理工大学）
Institute of Industrial Science, The University of Tokyo（东京大学工业科学研究所）；Microsoft（微软）
Robot navigation technology is required to accomplish difficult tasks in various environments. In navigation, it is necessary to know the information of the external environments and the state of the robot under the environment. On the other hand, various studies have been done on SLAM technology, which is also used for navigation, but also applied to devices for Mixed Reality and the like. In this paper, we propose a robot-device calibration method for navigation with a device using SLAM technology on a robot. The calibration is performed by using the position and orientation information give…
Image-based Visual Servo Control for Aerial Manipulation Using a Fully-Actuated UAV
ShanghaiTech University（上海科技大学）；Birla Institute of Technology and Science Pilani（比尔拉科学技术学院皮拉尼分校）；Pennsylvania State University（宾夕法尼亚州立大学）；Carnegie Mellon University（卡内基梅隆大学）
The ability to track a general walking path with specific timing is crucial to the operational safety and reliability of bipedal robots for avoiding dynamic obstacles, such as pedestrians, in complex environments. This paper introduces an online, full-body motion planner that generates the desired impact-aware motion for fully-actuated bipedal robotic walking. The main novelty of the proposed planner lies in its capability of producing desired motions in real-time that respect the discrete impact dynamics and the desired impact timing. To derive the proposed planner, a full-order hybrid dynami…
Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA（杜克大学医学院神经外科系）；Speed School of Engineering, University of Louisville, Louisville, KY, USA（路易斯维尔大学Speed工程学院）
This work details the design of a novel two finger robot gripper with multiple Gelsight based optical-tactile sensors covering the inner surface of the hand. The multiple Gelsight sensors can gather the surface topology of the object from multiple views simultaneously as well as can track the shear and tensile stress. In addition, other sensing modalities enable the hand to gather the thermal, acoustic and vibration information from the object being grasped. The force controlled gripper is fully actuated so that it can be used for various grasp configurations and can also be used for in-hand m…
The importance of humanoid robots in today's world is undeniable, one of the most important features of humanoid robots is the ability to maneuver in environments such as stairs that other robots can not easily cross. A suitable algorithm to generate the path for the bipedal robot to climb is very important. In this paper, an optimization-based method to generate an optimal stairway for under-actuated bipedal robots without an ankle actuator is presented. The generated paths are based on zero and non-zero dynamics of the problem, and according to the satisfaction of the zero dynamics constrain…
Practical use of robotic manipulators made from soft materials requires generating and executing complex motions. We present the first approach for generating trajectories of a thermally-actuated soft robotic manipulator. Based on simplified approximations of the soft arm and its antagonistic shape-memory alloy actuator coils, we justify a dynamics model of a discretized rigid manipulator with joint torques proportional to wire temperature. Then, we propose a method to calibrate this model from experimental data and demonstrate that the simulation aligns well with a hardware test. Finally, we …
Indian Institute of Technology Bombay（印度理工学院孟买分校）；General Electric Research（通用电气研究中心）
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…
A Comprehensive General Model of Tendon-Actuated Concentric Tube Robots with Multiple Tubes and Tendons
Healthcare Robotics and Telesurgery Laboratory (Heartlab)（医疗机器人与远程手术实验室）；University of Louisville（路易斯维尔大学）；Mechanical Engineering and Materials Science（机械工程与材料科学）；Duke University（杜克大学）；Department of Cardiac Surgery（心脏外科部门）；Boston Children’s Hospital（波士顿儿童医院）；Harvard Medical School（哈佛医学院）
In this paper, we propose a novel type of serial robot with minimal actuation. The robot is a serial rigid structure consisting of multiple links connected by passive joints and of movable actuators. The novelty of this robot is that the actuators travel over the links to a given joint and adjust the relative angle between the two adjacent links. The joints passively preserve their angles until one of the actuators moves them again. This actuation can be applied to any serial robot with two or more links. This unique configuration enables the robot to undergo the same wide range of motions typ…
We present a new framework for prioritized multi-task motion-force control of fully-actuated robots. This work is established on a careful review and comparison of the state of the art. Some control frameworks are not optimal, that is they do not find the optimal solution for the secondary tasks. Other frameworks are optimal, but they tackle the control problem at kinematic level, hence they neglect the robot dynamics and they do not allow for force control. Still other frameworks are optimal and consider force control, but they are computationally less efficient than ours. Our final claim is …
MIT CSAIL（麻省理工学院计算机科学与人工智能实验室）；University of Calgary（卡尔加里大学）
This paper introduces a cube-based reconfigurable robot that utilizes an electromagnet-based actuation framework to reconfigure in three dimensions via pivoting. While a variety of actuation mechanisms for self-reconfigurable robots have been explored, they often suffer from cost, complexity, assembly and sizing requirements that prevent scaled production of such robots. To address this challenge, we use an actuation mechanism based on electromagnets embedded into the edges of each cube to interchangeably create identically or oppositely polarized electromagnet pairs, resulting in repulsive or…
Boston University（波士顿大学）；Carnegie Mellon University（卡内基梅隆大学）
Untethered soft robots that locomote using electrothermally-responsive materials like shape memory alloy (SMA) face challenging design constraints for sensing actuator states. At the same time, modeling of actuator behaviors faces steep challenges, even with available sensor data, due to complex electrical-thermal-mechanical interactions and hysteresis. This article proposes a framework for in-situ sensing and dynamics modeling of actuator states, particularly temperature of SMA wires, which is used to predict robot motions. A planar soft limb is developed, actuated by a pair of SMA coils, tha…
We present a highly reactive controller which enables bipedal robots to blindly walk over various kinds of uneven terrains while resisting pushes. The high level motion planner does fast online optimization for footstep locations and Center of Mass (CoM) height using the decoupled actuated Spring Loaded Inverted Pendulum (aSLIP) model. The decoupled aSLIP model simplifies the original aSLIP with Linear Inverted Pendulum (LIP) dynamics in horizontal states and spring dynamics in the vertical state. The motion planning can be formulated as a discrete-time Model Predictive Control (MPC) and solve…
The potential diagnostic applications of magnet-actuated capsules have been greatly increased in recent years. For most of these potential applications, accurate position control of the capsule have been highly demanding. However, the friction between the robot and the environment as well as the drag force from the tether play a significant role during the motion control of the capsule. Moreover, these forces especially the friction force are typically hard to model beforehand. In this paper, we first designed a magnet-actuated tethered capsule robot, where the driving magnet is mounted on the…
University of Colorado Boulder（科罗拉多大学博尔德分校）；University of Calgary（卡尔加里大学）
We present PufferBot, an aerial robot with an expandable structure that may expand to protect a drone's propellers when the robot is close to obstacles or collocated humans. PufferBot is made of a custom 3D-printed expandable scissor structure, which utilizes a one degree of freedom actuator with rack and pinion mechanism. We propose four designs for the expandable structure, each with unique characterizations for different situations. Finally, we present three motivating scenarios in which PufferBot may extend the utility of existing static propeller guard structures. The supplementary video …
IIIT Hyderabad（海得拉巴国际信息技术学院）；Max Planck Institute for Intelligent Systems（马克斯·普朗克智能系统研究所）；Oregon State University（俄勒冈州立大学）
In this work, we consider a multi-wheeled payload transport system. Each of the wheels can be selectively actuated. When they are not actuated, wheels are free moving and do not consume battery power. The payload transport system is modeled as an actuated multi-agent system, with each wheel-motor pair as an agent. Kinematic and dynamic models are developed to ensure that the payload transport system moves as desired. We design optimization formulations to decide on the number of wheels to be active and which of the wheels to be active so that the battery is conserved and the wear on the motors…
Design, modeling, and characteristics of ringshaped robot actuated by functional fluid
Yamaguchi University（山口大学）；Schaeffler Intelligent Driving Technology (Changsha) Co., Ltd.（舍弗勒智能驾驶科技（长沙）有限公司）；Nagoya University（名古屋大学）；Nanjing University of Aeronautics and Astronautics（南京航空航天大学）
Walking quadruped robots face challenges in positioning their feet and lifting their legs during gait cycles over uneven terrain. The robot Laika is under development as a quadruped with a flexible, actuated spine designed to assist with foot movement and balance during these gaits. This paper presents the first set of hardware designs for the spine of Laika, a physical prototype of those designs, and tests in both hardware and simulations that show the prototype's capabilities. Laika's spine is a tensegrity structure, used for its advantages with weight and force distribution, and represents …
Indian Institute of Technology Bombay（印度理工学院孟买分校）；General Electric Research（通用电气研究中心）；Indian Institute of Technology, Bhubaneswar（印度理工学院布巴内斯瓦尔分校）
A spherical robot has many practical advantages as the entire electronics are protected within a hull and can be carried easily by any Unmanned Aerial Vehicle (UAV). However, its use is limited due to finding mounts for sensors. Pendulum actuated spherical robot provides space for mounting sensors at the yoke. We study the non-linear dynamics of a pendulum-actuated spherical robot to analyze the dynamics of internal assembly (yoke) for mounting sensors. For such robots, we provide a coupled dynamic model that takes care of the relationship between forward and sideways motion. We further demons…
Evaluation of an Actuated Spine in Agile Quadruped Locomotion
Department of Computer Science, Technical University of Darmstadt（德意志技术大学达姆施塔特分校计算机科学系）；IDEAS Research Institute（IDEAS研究所）；Institute of Robotics and Machine Intelligence, Poznan University of Technology（波兹南技术大学机器人与机器智能研究所）
The University of Manchester（曼彻斯特大学）；Chulalongkorn University（朱拉隆功大学）
Robots have been critical instruments to space exploration by providing access to environments beyond human limitations. Jumping robot concepts are attractive solutions to negotiate complex terrain. However, among the engineering challenges to overcome to enable jumping robot concepts for sustained operation, reduction of mechanical failure modes is one of the most fundamental. This study set out to develop a jumping robot with focus on minimal actuation for reduced mechanism maintenance. We present the synthesis of a Sarrus-style linkage to constraint the system to a single translational degr…
To address the operational challenges of in-pipe robots in large pipes of water distribution systems (WDS), in this research, a control algorithm is proposed for our previously designed robot [4]. Our size adaptable robot has an under-actuated modular design that can be used for both leak detection and quality monitoring. First, nonlinear dynamical governing equations of the robot are derived with the definition of two perpendicular planes, and two sets of states are defined for the robot for stabilization and mobilization. For stabilization, we calculated the auxiliary system matrices and des…
Robotics Institute, Carnegie Mellon University（卡内基梅隆大学机器人研究所）；University of Pittsburgh（匹兹堡大学）
The introduction of fully-actuated multirotors has opened the door to new possibilities and more efficient solutions to many real-world applications. However, their integration had been slower than expected, partly due to the need for new tools to take full advantage of these robots. As far as we know, all the groups currently working on the fully-actuated multirotors develop new full-pose (6-D) tools and methods to use their robots, which is inefficient, time-consuming, and requires many resources. We propose a way of bridging the gap between the tools already available for underactuated robo…
Tendon-Actuated Robots with a Tapered, Flexible Polymer Backbone: Design, Fabrication, and Modeling
Mechatronics, Robotics and Operation Section, European Organization for Nuclear Research (CERN)（欧洲核子研究组织（CERN）机电学、机器人学与操作部门）；Department of Aeronautics and Astronautics, University of Washington（华盛顿大学航空与航天系）；Department of Engineering Cybernetics, Norwegian University of Science and Technology (NTNU)（挪威科学技术大学（NTNU）工程 cybernetics 部门）
Collision Risk Quantification and Conflict Resolution in Trajectory Tracking for Acceleration-Actuated Multi-Robot Systems
Harbin Institute of Technology Shenzhen（哈尔滨工业大学（深圳））；Guangdong Provincial Key Laboratory of Novel Security Intelligence Technologies（广东省新型安全智能技术重点实验室）；Southern University of Science and Technology（南方科技大学）；University of Oulu（奥卢大学）
Sim-to-Real Transfer for Muscle-Actuated Robots via Generalized Actuator Networks
Max Planck Institute for Intelligent Systems（马克斯·普朗克智能系统研究所）；Boston University（波士顿大学）；University of Oxford（牛津大学）；University of Alberta（阿尔伯塔大学）；Alberta Machine Intelligence Institute (Amii)（阿尔伯塔机器智能研究所（Amii））
University of California, Santa Barbara（加州大学圣巴巴拉分校）
Soft robots promise improved safety and capability over rigid robots when deployed in complex, delicate, and dynamic environments. However, the infinite degrees of freedom and highly nonlinear dynamics of these systems severely complicate their modeling and control. As a step toward addressing this open challenge, we apply the data-driven, Hankel Dynamic Mode Decomposition (HDMD) with time delay observables to the model identification of a highly inertial, helical soft robotic arm with a high number of underactuated degrees of freedom. The resulting model is linear and hence amenable to contro…
This paper introduces a new approach to studying bipedal locomotion. The approach is based on magnetically actuated miniature robots. Building prototypes of bipedal locomotion machines has been very costly and overly complicated. We demonstrate that a magnetically actuated 0.3~gm robot, we call Big Foot, can be used to test fundamental ideas without necessitating very complex and expensive bipedal machines. We explore analytically and experimentally two age old questions in bipedal locomotion: 1. Can such robots be driven with pure hip actuation. 2. Is it better to use continuous or impulsive …
Neural Operators for Design-Space Surrogate Modeling of Tendon-Actuated Continuum Robots
The Robotics Center and the Kahlert School of Computing at the University of Utah（犹他大学机器人中心和Kahlert计算学院）；The Departments of Computer Science and Electrical and Computer Engineering at Vanderbilt University（范德比大学计算机科学与电气与计算机工程系）
The University of Tokyo（东京大学）；University of Calgary（卡尔加里大学）；IIIT-Delhi（德里印度理工学院）；University of Chicago（芝加哥大学）
This paper introduces Sketched Reality, an approach that combines AR sketching and actuated tangible user interfaces (TUI) for bidirectional sketching interaction. Bi-directional sketching enables virtual sketches and physical objects to "affect" each other through physical actuation and digital computation. In the existing AR sketching, the relationship between virtual and physical worlds is only one-directional -- while physical interaction can affect virtual sketches, virtual sketches have no return effect on the physical objects or environment. In contrast, bi-directional sketching interac…
