In modern robotic applications, tactile sensor arrays (i.e., artificial skins) are an emergent solution to determine the locations of contacts between a robot and an external agent. Localizing the point of contact is useful but determining the force applied on the skin provides many additional possibilities. This additional feature usually requires time-consuming calibration procedures to relate the sensor readings to the applied forces. This letter presents a novel device that enables the calibration of tactile sensor arrays in a fast and simple way. The key idea is to design a plenum chamber where the skin is inserted, and then the calibration of the tactile sensors is achieved by relating the air pressure and the sensor readings. This general concept is tested experimentally to calibrate the skin of the iCub robot. The validation of the calibration device is achieved by placing the masses of known weight on the artificial skin and comparing the applied force against the one estimated by the sensors.
National Institute of Standards and Technology（美国国家标准与技术研究院）
The existence of tactile afferents sensitive to slip-related mechanical transients in the human hand augments the robustness of grasping through secondary force modulation protocols. Despite this knowledge and the fact that tactile-based slip detection has been researched for decades, robust slip detection is still not an out-of-the-box capability for any commercially available tactile sensor. This research seeks to bridge this gap with a comprehensive study addressing several aspects of slip detection. Key developments include a systematic data collection process yielding millions of sensory …
Curvature-Aware Calibration of Tactile Sensors for Accurate Force Estimation on Non-Planar Surfaces
School of Electrical and Computer Engineering（电气与计算机工程学院）；Cornell University（康奈尔大学）；Sibley School of Mechanical and Aerospace Engineering（机械与航空航天工程学院）；Dept. of Mechanical Engineering（机械工程系）；Virginia Tech（弗吉尼亚理工大学）
Technische Universität München（慕尼黑工业大学）；fortiss（弗劳恩霍夫软件与系统技术研究所（fortiss））；sensed.io UG (haftungsbeschränkt)（sensed.io有限责任公司）
We study the responses of two tactile sensors, the fingertip sensor from the iCub and the BioTac under different external stimuli. The question of interest is to which degree both sensors i) allow the estimation of force exerted on the sensor and ii) enable the recognition of differing degrees of curvature. Making use of a force controlled linear motor affecting the tactile sensors we acquire several high-quality data sets allowing the study of both sensors under exactly the same conditions. We also examined the structure of the representation of tactile stimuli in the recorded tactile sensor …
Calibration-Free Surface Normals Estimation in Vision-Based Tactile Sensing using Universal Photometric Stereo
TU Dresden（德累斯顿工业大学）；TUD Dresden University of Technology（德累斯顿工业大学）；Centre for Tactile Internet with Human-in-the-Loop (CeTI)（人在环触觉互联网中心（CeTI））；DKFZ（德国癌症研究中心）；University Hospital Carl Gustav Carus（卡尔·古斯塔夫·卡鲁斯大学医院）；Helmholtz-Zentrum Dresden-Rossendorf (HZDR)（德累斯顿-罗森多夫亥姆霍兹中心（HZDR））
Due to the complexity of modeling the elastic properties of materials, the use of machine learning algorithms is continuously increasing for tactile sensing applications. Recent advances in deep neural networks applied to computer vision make vision-based tactile sensors very appealing for their high-resolution and low cost. A soft optical tactile sensor that is scalable to large surfaces with arbitrary shape is discussed in this paper. A supervised learning algorithm trains a model that is able to reconstruct the normal force distribution on the sensor's surface, purely from the images record…
The University of Hong Kong（香港大学）；CNRS-University of Montpellier（法国国家科学研究中心-蒙彼利埃大学）；Centre for Transformative Garment Production（转化制衣生产中心）
Human skin can accurately sense the self-decoupled normal and shear forces when in contact with objects of different sizes. Although there exist many soft and conformable tactile sensors on robotic applications able to decouple the normal force and shear forces, the impact of the size of object in contact on the force calibration model has been commonly ignored. Here, using the principle that contact force can be derived from the light power loss in the soft optical fiber core, we present a soft tactile sensor that decouples normal and shear forces and calibrates the measurement results based …
Shanghai Qi Zhi Institute（上海期智研究院）；Tsinghua University（清华大学）；Massachusetts Institute of Technology（麻省理工学院）
Vision-based tactile sensors that can measure 3D geometry of the contacting objects are crucial for robots to perform dexterous manipulation tasks. However, the existing sensors are usually complicated to fabricate and delicate to extend. In this work, we novelly take advantage of the reflection property of semitransparent elastomer to design a robust, low-cost, and easy-to-fabricate tactile sensor named DTact. DTact measures high-resolution 3D geometry accurately from the darkness shown in the captured tactile images with only a single image for calibration. In contrast to previous sensors, D…
Hong Kong University of Science and Technology（香港科技大学）
Retrieving rich contact information from robotic tactile sensing has been a challenging, yet significant task for the effective perception of object properties that the robot interacts with. This work is dedicated to developing an algorithm to estimate contact force and torque for vision-based tactile sensors. We first introduce the observation of the contact deformation patterns of hyperelastic materials under ideal single-axial loads in simulation. Then based on the observation, we propose a method of estimating surface forces and torque from the contact deformation vector field with the Hel…
MVP-Tac: A Miniaturized Dual-Modal Vision and Photoelastic Tactile Sensor for Robot-Assisted Minimally Invasive Surgery
Elmore Family School of Electrical and Computer Engineering, Purdue University（普渡大学埃尔莫尔电气与计算机工程学院）；Edwardson School of Industrial Engineering, Purdue University（普渡大学爱德华森工业工程学院）；School of Mechanical Engineering, Purdue University（普渡大学机械工程学院）；Robotics Engineering Technology, Purdue University（普渡大学机器人工程技术学院）；Department of Civil Engineering, Stony Brook University（石溪大学土木工程系）；Department of Mechanical Engineering, Michigan State University（密歇根州立大学机械工程系）
MagCilia: A Compact Magnetociliary Tactile Sensor with 3D Force Sensing for Robotic Contact Perception and Grasping Feedback
National University of Singapore（新加坡国立大学）；University of California, Berkeley（加州大学伯克利分校）；City University of Hong Kong（香港城市大学）；City University of Hong Kong Shenzhen Research Institute（香港城市大学深圳研究院）
Xi’an-Jiaotong Liverpool University（西交利物浦大学）；The University of Hong Kong（香港大学）；City University of Hong Kong（香港城市大学）；Southern University of Science and Technology（南方科技大学）
We propose a deep visuo-tactile model for realtime estimation of the liquid inside a deformable container in a proprioceptive way.We fuse two sensory modalities, i.e., the raw visual inputs from the RGB camera and the tactile cues from our specific tactile sensor without any extra sensor calibrations.The robotic system is well controlled and adjusted based on the estimation model in real time. The main contributions and novelties of our work are listed as follows: 1) Explore a proprioceptive way for liquid volume estimation by developing an end-to-end predictive model with multi-modal convolut…
Czech Technical University in Prague（布拉格捷克理工大学）；Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague（布拉格捷克理工大学捷克信息学、机器人学与控制论研究所）
Mechanism calibration is an important and non-trivial task in robotics. Advances in sensor technology make affordable but increasingly accurate devices such as cameras and tactile sensors available, making it possible to perform automated self-contained calibration relying on redundant information in these sensory streams. In this work, we use a simulated iCub humanoid robot with a stereo camera system and end-effector contact emulation to quantitatively compare the performance of kinematic calibration by employing different combinations of intersecting kinematic chains -- either through self-…
Tactile perception is an essential ability of intelligent robots in interaction with their surrounding environments. This perception as an intermediate level acts between sensation and action and has to be defined properly to generate suitable action in response to sensed data. In this paper, we propose a feedback approach to address robot grasping task using force-torque tactile sensing. While visual perception is an essential part for gross reaching, constant utilization of this sensing modality can negatively affect the grasping process with overwhelming computation. In such case, human bei…
Enabling Tactile Feedback for Robotic Strawberry Handling using AST Skin
Lincoln Institute of Agri-food Technology, University of Lincoln（林肯大学食品农业技术学院）；School of Computer Science, University of Lincoln（林肯大学计算机科学学院）；University of Surrey（萨里大学）
A Precise Real-Time Force-Aware Grasping System for Robust Aerial Manipulation
State Key Laboratory of Industrial Control Technology, Zhejiang University（浙江大学工业控制技术状态重点实验室）；Huzhou Institute, Zhejiang University（浙江大学湖州研究院）；State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University（浙江大学流体动力与机械系统状态重点实验室）；Zhejiang Key Laboratory of Additive Manufacturing Technology and Equipment, School of Mechanical Engineering, Zhejiang University（浙江省增材制造技术与装备重点实验室）
This work describes the development of a high-resolution tactile-sensing finger for robot grasping. This finger, inspired by previous GelSight sensing techniques, features an integration that is slimmer, more robust, and with more homogeneous output than previous vision-based tactile sensors. To achieve a compact integration, we redesign the optical path from illumination source to camera by combining light guides and an arrangement of mirror reflections. We parameterize the optical path with geometric design variables and describe the tradeoffs between the finger thickness, the depth of field…
Learning Gentle Grasping Using Vision, Sound, and Touch
Learning, Adaptive Systems, and Robotics (LASR) Lab, TU Dresden（图腾德斯登技术大学学习、自适应系统与机器人实验室）；Center for Tactile Internet with Human-in-the-Loop (CeTI)（人机协同触觉互联网中心）
DOT-Sim: Differentiable Optical Tactile Simulation with Precise Real-to-Sim Physical Calibration
Stanford University（斯坦福大学）；University of Cambridge（剑桥大学）；Toyota Research Institute University 2.0 Program（丰田研究院大学2.0计划）；ARL grant W911NF-21-2-0104（ARL授予的W911NF-21-2-0104项目）；Vannevar Bush Faculty Fellowship（范内var布什教职 fellowship）；Flexiv corporation（Flexiv公司）；Shanghai Jiao Tong University（上海交通大学）
ViTacGen: Robotic Pushing with Vision-to-Touch Generation
Department of Engineering, King’s College London（工程系，伦敦国王学院）；Department of Engineering Mathematics and Bristol, Robotics Laboratory, University of Bristol（工程数学系及布里斯托尔机器人实验室，布里斯托尔大学）
Perceiving the environment through touch is important for robots to reach in cluttered environments, but devising a way to sense without disturbing objects is challenging. This work presents the design and modelling of whisker-inspired sensors that attach to the surface of a robot manipulator to sense its surrounding through light contacts. We obtain a sensor model using a calibration process that applies to straight and curved whiskers. We then propose a sensing algorithm using Bayesian filtering to localize contact points. The algorithm combines the accurate proprioceptive sensing of the rob…
Columbia University（哥伦比亚大学）；Robotics at Google（谷歌机器人）
Vision-based grasping systems typically adopt an open-loop execution of a planned grasp. This policy can fail due to many reasons, including ubiquitous calibration error. Recovery from a failed grasp is further complicated by visual occlusion, as the hand is usually occluding the vision sensor as it attempts another open-loop regrasp. This work presents MAT, a tactile closed-loop method capable of realizing grasps provided by a coarse initial positioning of the hand above an object. Our algorithm is a deep reinforcement learning (RL) policy optimized through the clipped surrogate objective wit…
TactileReflex: Noise-Statistics-Driven Vision-Tactile Reflex Control for Force-Sensitive Manipulation
Thrust of Robotics and Autonomous Systems, The Hong Kong University of Science and Technology (Guangzhou)（机器人与自主系统研究所，香港科学与技术大学（广州））；School of Mechanical Engineering, Shanghai Jiao Tong University（上海交通大学机械工程学院）
Tactile-based force estimation for interaction control with robot fingers
Institut des sytèmes intelligents et de la robotique, Sorbonne University（索邦大学智能与机器人系统研究所）；LIRMM, Montpellier University（蒙彼利埃大学LIRMM实验室）；Nantes Université, École Centrale Nantes, CNRS, LS2N（南特大学、南特中央理工学院、法国国家科学研究中心、南特数字科学实验室）
Sensor embedded glove systems have been reported to require careful, time consuming and precise calibrations on a per user basis in order to obtain consistent usable data. We have developed a low cost, flex sensor based smart glove system that may be resilient to the common limitations of data gloves. This system utilizes an Arduino based micro controller as well as a single flex sensor on each finger. Feedback from the Arduinos analog to digital converter can be used to infer objects dimensional properties, the reactions of each individual finger will differ with respect to the size and shape…
CATCH-FORM-ACTer: Compliance-Aware Tactile Control and Hybrid Deformation Regulation-Based Action Transformer for Viscoelastic Object Manipulation
School of Automation Science and Engineering, South China University of Technology（华南理工大学自动化科学与工程学院）；Institute for Super Robotics (Huangpu)（黄埔智能机器人研究院）
