52 accepted papers
Camera-to-robot (also known as eye-to-hand) calibration is a critical component of vision-based robot manipulation. Traditional marker-based methods often require human intervention for system setup. Furthermore, existing autonomous markerless calibration methods typically rely on pre-trained robot
This paper introduces Model Q-II, an enhanced underactuated robotic hand designed to improve dexterous manipulation through expanded grasping modes and manipulation primitives. The Model Q-II incorporates tripod and enhanced power grasping modes, achieving increased versatility without adding additi
Traditional robot control relies on analytical methods that require precise system models, which are hard to apply in real-world settings and limit generalization to arbitrary tasks. However, systems like serial manipulators and passively adaptive hands feature inherently stable regions without cont
Identifying predictive world models for robots from sparse online observations is essential for robot task planning and execution in novel environments. However, existing methods that leverage differentiable programming to identify world models are incapable of jointly optimizing the geometry, appea
The ability to plan and control robotic in-hand manipulation is challenged by several issues, including the required amount of prior knowledge of the system and the sophisticated physics that varies across different robot hands or even grasp instances. One of the most direct models of in-hand manipu…
Continuous exploration without interruption is important in scenarios such as search and rescue and precision agriculture, where consistent presence is needed to detect events over large areas. Ergodic search already derives continuous trajectories in these scenarios so that a robot spends more time…
Calibrating robots into their workspaces is crucial for manipulation tasks. Existing calibration techniques often rely on sensors external to the robot (cameras, laser scanners, etc.) or specialized tools. This reliance complicates the calibration process and increases the costs and time requirement…
This systems paper presents the implementation and design of RB5, a wheeled robot for autonomous long-term exploration with fewer and cheaper sensors. Requiring just an RGB-D camera and low-power computing hardware, the system consists of an experimental platform with rocker-bogie suspension. It ope…
Robot manipulation today generally focuses on motions exclusively with a robot arm or a dexterous hand, but usually not a combination of both. However, complex manipulation tasks can require coordinating arm and hand motions that leverage capabilities of both, much like the coordinated arm and hand…
Building hand-object models for dexterous in-hand manipulation remains a crucial and open problem. Major challenges include the difficulty of obtaining the geometric and dynamical models of the hand, object, and time-varying contacts, as well as the inevitable physical and perception uncertainties.…
Contact can be conceptualized as a set of constraints imposed on two bodies that are interacting with one another in some way. The nature of a contact, whether a point, line, or surface, dictates how these bodies are able to move with respect to one another given a force, and a set of contacts can p…
Constraining contacts to remain fixed on an object during manipulation limits the potential workspace size, as motion is subject to the hand’s kinematic topology. Finger gaiting is one way to alleviate such restraints. It allows contacts to be freely broken and remade so as to operate on different m
Modular Active Cell Robots (MACROs) is an approach for modular robot hardware that leverages simple components such as actuators and compliant joints to make large deformable robotic structures. In this letter, we consider the planar triangular lattice and its sparser variants as the candidate mesh
This letter presents an algorithm to simultaneously reconstruct the geometry of an unknown object and its environment via physical interactions. Applications involving highly cluttered or occluded workspaces prevent the effective use of vision. To address some of the challenges that arise, we propos
The papers in this special section focus on benchmarking protocols for robotic manipulation. Benchmarks are crucial for analyzing the effectiveness of an approach against a common basis, providing a quantitative means for interpreting performance. Carefully designed and widely recognized benchmarks
Substantial advancements to model-based reinforcement learning algorithms have been impeded by the model-bias induced by the collected data, which generally hurts performance. Meanwhile, their inherent sample efficiency warrants utility for most robot applications, limiting potential damage to the r…
Rotating a grasped object about all three spatial axes is challenging, because kinematically redundant robot hands require complex control schemes for within-hand rotations, and simple parallel grippers require inefficient whole arm motions. We present a novel 3-finger robot hand design inspired by…
In this work, we propose a pick-and-place benchmark to assess the manipulation capabilities of a robotic system. The benchmark is based on the Box and Blocks Test (BBT), a task utilized for decades by the rehabilitation community to assess unilateral gross manual dexterity in humans. We propose thre
Prosthetic and robotic grippers rely on soft finger pads to better acquire objects of varying size, shape and surface. However, the frictional behavior of soft finger pads of different designs and geometries have yet to be quantitatively compared, in large part due to the difficulty in modeling soft
Grasping can be conceptualized as the ability of an end-effector to temporarily attach or fixture an object to a manipulator-constraining all motion of the workpiece with respect to the end-effector's base frame. This seemingly simplistic action often requires excessive sensing, computation, or cont…
We address the problem of controlling a partially constrained trajectory of the manipulation frame-an arbitrary frame of reference rigidly attached to the object-as the desired motion about this frame is often underdefined. This may be apparent, for example, when the task requires control only about
To date, many control strategies for legged robots have been proposed for stable locomotion over rough and unstructured terrains. However, these approaches require sensing information throughout locomotion, which may be noisy or unavailable at times. An alternative solution to rough terrain locomoti…
In this paper we present a novel method of categorizing naturalistic human arm motions during activities of daily living using clustering techniques. While many current approaches attempt to define all arm motions using heuristic interpretation, or a combination of several abstract motion primitives…
We address the problem of developing precision, quasi-static control strategies for fingertip manipulation in robot hands. In general, analytically specifying useful object transition maps, or hand-object Jacobians, for scenarios in which there is uncertainty in some key aspect of the hand-object sy…
In this paper we address the problem of creating planar caging grasps on objects using simple, underactuated grippers with no sensing or control. Specifically, we examine how changes in mechanical compliance, passive adaptability due to underactuation, and finger phalanx length affect the ability to…
In this work, we present a within-hand manipulation approach that leverages a simple energy model based on caging grasps made by underactuated hands. Instead of explicitly modeling the contacts and dynamics in manipulation, we can calculate a map to describe the energy states of different hand-objec…
Fully actuated multifingered robotic hands are often expensive and fragile. Low-cost underactuated hands are appealing but present challenges due to the lack of analytical models. This letter aims to learn a stochastic version of such models automatically from data with minimum user effort. The focu
In this work, we investigate a mechanics-inspired framework for describing fingertip-based planar within-hand manipulation with an underactuated robotic gripper. In particular, this framework leverages fundamental mechanics properties of the hand-object system, including basic terms such as local co…
We address the problem of pregrasp sliding manipulation, which is an essential skill when a thin object cannot be directly grasped from a flat surface. Leveraged on the passive reconfigurability of soft, compliant, or underactuated robotic hands, we formulate this problem as an integrated motion and
In this paper, we present a constrained optimization framework for evaluating the post-contact stability of underactuated precision grasping configurations with a single degree of actuation. Relationships between key anthropomorphic design parameters including link length ratios, transmission ratios…
This paper discusses the kinematic design and geometric optimization of a novel hybrid three degree-of-freedom (DOF) wrist mechanism. The architecture consists of a one prismatic-revolute-universal linkage and one prismatic-spherical-spherical linkage in parallel with a revolute-universal linkage. T…
In this work, we investigate methods to detect four phenomena (modes) that occur during prehensile fingertip-based within-hand manipulation without the use of tactile sensors. By using actuator states and visual data, we aim to recognize different modes of operation such as interpreting if the hand…
The human hand is able to achieve an unparalleled diversity of manipulation actions. One contributor to this capability is the structure of the human finger pad, where soft internal tissue is surrounded by a layer of more rigid skin. This permits conforming of the finger pad around object contours f
It is very challenging for a robotic gripper to achieve large reorientations with grasped objects without accidental object ejection. This paper presents a simple gripper that can repeatedly achieve large reorientations over π/2 rad through the kinematics of the hand-object system alone, without the…
This paper studies the synthesis of between-leg coupling schemes for passively-adaptive non-redundant legged robots. Highly actuated legged robots can arbitrarily locate their feet relative to their bodies through active control, but often wind up kinematically over-constrained following ground cont…
Adaptive robot hands have changed the way we approach and think of robot grasping and manipulation. Traditionally, pinch, fingertip grasping and dexterous, in-hand manipulation tasks were executed with fully actuated, rigid robot hands and relied on analytic methods, computation of the hand object J…
In this paper, we present a novel robotic hand specifically designed for dexterous spatial manipulation. Unlike most other dexterous hand designs that attempt to mimic the kinematic structure of the human hand, the proposed mechanism instead is based on the non-anthropomorphic “hexapod” structure of…
In this paper we investigate a series of candidate regular planar mesh geometries in terms of their suitability for utilization as mesh primitives for constructing compliant robotic structures. In prior work, we established a framework of compliant, articulate robotic meshes, termed Modular Active C…
A new class of simple, adaptive, under-actuated and compliant robot hands has recently attracted the interest of the robotics community. The under-actuated mechanisms and the structural compliance used in these hands facilitate and robustify not only grasping but also the execution of dexterous, in-…
In this letter, we explore the shape control of compliant, articulated meshes created from shape memory alloy (SMA)-based linear actuators (Active Cells). These compliant meshes form the mechanical subsystem of a class of proposed modular active-cell robots (MACROs). Our “Active Cells” are centimete
Human in-hand dexterity can be highly fluid and unstructured, but in contrast, prevailing research in robotic manipulation has focused on highly structured, well-controlled motions where contact points are carefully characterized. Maintaining grasp stability through traditional closure conditions du…
Precision manipulation with underactuated hands is a challenging problem due to difficulties in obtaining precise gripper, object and contact models. Using vision feedback provides a degree of robustness to modeling inaccuracies, but conventional visual servoing schemes may suffer from performance d…
While designing robot hands based on grasping data is more common, fewer previous works have used details of human manipulation kinematics to improve robot hand design. The current work involves an underactuated, tendon driven, anthropomorphic manipulator with two flexor tendons and an abduction-add…
In this letter, we present the design of an underactuated three-fingered robotic hand and evaluate its performance. The hand utilizes radially symmetric, prismatically actuated fingers controlled by a single actuator. Each finger consists of a single joint finger connected to the prismatic joint via
This paper presents a minimalistic handheld haptic interface designed to provide pedestrian navigation assistance via the intuitive and unobtrusive stimulus of shape-changing. The new device, named the Haptic Taco, explores a novel region of robotic interfaces which we believe to have benefits over
In this paper, we propose a hybrid methodology based on a combination of analytical, numerical and machine learning methods for performing dexterous, in-hand manipulation with simple, adaptive robot hands. A constrained optimization scheme utilizes analytical models that describe the kinematics of a…
In this paper, a method is proposed for vision-based within-hand precision manipulation with underactuated grippers. The method combines the advantages of adaptive underactuation with the robustness of visual servoing algorithms by employing simple action sets in actuator space, called precision man…
We present the design of simple, centimeter-scale modular actuation units (“Active Cells”) and passive compliant nodes that are electromechanically networked to create macroscopically deformable Modular Active Cell-based Structures (MACROs). Each Active Cell is a single degree-of-freedom linear actu…
In this paper we investigate effects of the mass, kinematic constraints imposed by the joint, and assistance provided by the spring of a pair of quasi-passive knee exoskeletons on the motion of the human body center of mass during normal walking. The exoskeletons implement a spring in parallel with…
While techniques exist for the rapid prototyping of mechanical and electrical components separately, this paper describes a method where commercial Additive Manufacturing (AM) techniques can be used to concurrently construct the mechanical structure and electronic circuits in a robotic or mechatroni…
The design of finger pads for robotic and prosthetic hands is often overlooked, with relatively simple shapes and mechanical properties typically used. The finger pad geometry and mechanical properties are especially important for within-hand dexterous manipulation, and human finger usage patterns s…
In this paper we present a methodology for discriminating between different objects using only a single force closure grasp with an underactuated robot hand equipped with force sensors. The technique leverages the benefits of simple, adaptive robot grippers (which can grasp successfully without prio…