# IEEE Robotics and Automation Letters

## Issue 99

Early Access articles are new content made available in advance of the final electronic or print versions and result from IEEE's Preprint or Rapid Post processes. Preprint articles are peer-reviewed but not fully edited. Rapid Post articles are peer-reviewed and edited but not paginated. Both these types of Early Access articles are fully citable from the moment they appear in IEEE Xplore.

## Filter Results

Displaying Results 1 - 25 of 79
• ### Local Descriptor for Robust Place Recognition using LiDAR Intensity

Publication Year: 2019, Page(s): 1
| | PDF (5343 KB)

Place recognition is a challenging problem in mobile robotics, especially in unstructured environments or under viewpoint and illumination changes. Most LiDAR-based methods rely on geometrical features to overcome such challenges, as generally scene geometry is invariant to these changes, but tend to affect camera-based solutions significantly. Compared to cameras, however, LiDARs lack the strong ... View full abstract»

• ### HMFP-DBRNN: Real-time Hand Motion Filtering and Prediction via Deep Bidirectional RNN

Publication Year: 2019, Page(s): 1
| | PDF (1162 KB)

Pathological hand tremor (PHT) is among the most common movement symptoms of several neurological disorders including Parkinson's Disease (PD) and Essential Tremor (ET). Extracting PHT is of paramount importance in several engineering and clinical applications such as assistive and robotic rehabilitation technologies. In such systems, PHT is modeled as the input noise to the system and thus there ... View full abstract»

• ### Optimal Structure Synthesis for Environment Augmenting Robots

Publication Year: 2019, Page(s): 1
| | PDF (3357 KB)

Building structures can allow a robot to surmount large obstacles, expanding the set of areas it can reach. This paper presents a planning algorithm to automatically determine what structures a construction-capable robot must build in order to traverse its entire environment. Given an environment, a set of building blocks, and a robot capable of building structures, we seek a optimal set of struct... View full abstract»

• ### Thermal Recovery of Multi-Limbed Robots with Electric Actuators

Publication Year: 2019, Page(s): 1
| | PDF (3885 KB)

The problem of finding thermally minimizing configurations of a humanoid robot to recover its actuators from unsafe thermal states is addressed. A first-order, data-driven, effortbased, thermal model of the robot's actuators is devised, which is used to predict future thermal states. Given this predictive capability, a map between configurations and future temperatures is formulated to find what c... View full abstract»

• ### Learning to Predict Ego-Vehicle Poses for Sampling-Based Nonholonomic Motion Planning

Publication Year: 2019, Page(s): 1
| | PDF (4205 KB)

Sampling-based motion planning is an effective tool to compute safe trajectories for automated vehicles in complex environments. However, a fast convergence to the optimal solution can only be ensured with the use of problem-specific sampling distributions. Due to the large variety of driving situations within the context of automated driving, it is very challenging to manually design such distrib... View full abstract»

• ### New Automated Guided Vehicle System using Real-time Holonic Scheduling for Warehouse Picking

Publication Year: 2019, Page(s): 1
| | PDF (474 KB)

We propose a new robotic system using an automated guided vehicle (AGV for order picking in logistics warehouses. In AGV picking systems, AGVs transport the entire shelves including the required items (inventory shelves) or shipping boxes (sorting shelves) to the pickers instead of the pickers moving to the shelves, which improves the productivity of the picking activity in warehouses. In conventi... View full abstract»

• ### Application of a Redundant Haptic Interface in Enhancing Soft-Tissue Stiffness Discrimination

Publication Year: 2019, Page(s): 1
| | PDF (1086 KB)

Haptic-enabled teleoperated surgical systems have the potential to enhance the accuracy and performance of surgical interventions. The user interface of such a system can provide haptic feedback to the surgeon to more intuitively perform surgical tasks. In this paper, we study the added benefits of redundant manipulators as haptic interfaces for teleoperated surgical systems. First, we introduce t... View full abstract»

• ### Comparison of Modeling Approaches for a Tendon Actuated Continuum Robot with Three Extensible Segments

Publication Year: 2019, Page(s): 1
| | PDF (2115 KB)

Continuum robots actuated by tendons are a widely researched robot design offering high dexterity and large workspaces relative to their volume. Their flexible and compliant structure can be easily miniaturized, making them predestined for applications in difficult-to-reach and confined spaces. Adaptions of this specific robot design include extensible segments leading to an even higher manipulabi... View full abstract»

• ### Degenerate Motion Analysis for Aided INS with Online Spatial and Temporal Sensor Calibration

Publication Year: 2019, Page(s): 1
| | PDF (1819 KB)

In this paper we perform in-depth observability analysis for both spatial and temporal calibration parameters of an aided inertial navigation system (INS) with global and/or local sensing modalities. In particular, we analytically show that both spatial and temporal calibration parameters are observable if the sensor platform undergoes random motion. More importantly, we identify four degenerate m... View full abstract»

• ### A Model-Free Extremum-Seeking Approach to Autonomous Excavator Control Based on Output Power Maximization

Publication Year: 2019, Page(s): 1
| | PDF (995 KB)

A new approach to autonomous excavator control that allows the machine to adapt to unknown soil properties is presented. Unlike traditional force control or trajectory control, the new method uses the product of force and velocity, namely, the power transmitted from the excavator to the soil, as a signal for adaptive excavation. Using an extremum-seeking algorithm, an optimal excavation condition ... View full abstract»

• ### Vision-Based Control and Stability Analysis of a Cable-Driven Parallel Robot

Publication Year: 2019, Page(s): 1
| | PDF (1938 KB)

In Cable-Driven Parallel Robots (CDPRs) rigid links are substituted by flexible cables. This change in actuation allows for a large workspace with a high payload to weight ratio, among other appealing characteristics. However the accuracy for such systems needs to be improved to truly outperform classical parallel robots. A possible and not yet well studied solution is the use of vision-based cont... View full abstract»

• ### Nanoliter Fluid Handling for Microbiology via Levitated Magnetic Microrobots

Publication Year: 2019, Page(s): 1
| | PDF (2333 KB)

Microbiological environments are a clear application area for microscale robotics, but targeted delivery of biochemical cues to selected cells and tissues remains a significant challenge. This challenge is compounded by the sheer numbers of cells that compose tissues. Multirobot system development has been limited due to challenges in discrete operation of several robots in a confined space. Here,... View full abstract»

• ### Vision-based Online Learning Kinematic Control for Soft Robots using Local Gaussian Process Regression

Publication Year: 2019, Page(s): 1
| | PDF (3484 KB)

Soft robots, owing to their elastomeric material, ensure safe interaction with their surroundings. These robot compliance properties inevitably impose a trade-off against precise motion control, as to which conventional model-based methods were proposed to approximate the robot kinematics. However, too many parameters, regarding robot deformation and external disturbance, are difficult to obtain, ... View full abstract»

• ### Avoidance of Convex and Concave Obstacles with Convergence ensured through Contraction

Publication Year: 2019, Page(s): 1
| | PDF (4556 KB)

This paper presents a closed-form approach to obstacle avoidance for multiple moving convex and star-shaped concave obstacles. The method takes inspiration in harmonic-potential fields. It inherits the convergence properties of harmonic potentials. We prove impenetrability of the obstacle's hull and asymptotic stability at a final goal location, using contraction theory. We validate the approach i... View full abstract»

• ### General Hand-Eye Calibration Based on Reprojection Error Minimization

Publication Year: 2019, Page(s): 1
| | PDF (1150 KB)

This paper describes a novel hand-eye calibration technique based on reprojection error minimization. In contrast to traditional hand-eye calibration methods, the proposed method directly takes images of the calibration pattern and does not require to explicitly estimate the camera pose for each input image. The proposed method is implemented as a pose graph optimization problem, so that it can so... View full abstract»

• ### Acausal Approach to Motion Cueing

Publication Year: 2019, Page(s): 1
| | PDF (1966 KB)

Motion simulators have been used extensively by both industry and academia to train pilots, conduct psychological experiments on drivers, understand the perception of motion by humans, and cater to the burgeoning gaming industry among others. Working of a motion simulator can be summarized in following three steps: i) acquisition of motion signals, ii) motion cueing: signal processing to generate ... View full abstract»

• ### Design of a Compliant Mechanical Device for Upper-Leg Rehabilitation

Publication Year: 2019, Page(s): 1
| | PDF (2310 KB)

In this paper, we introduce a fully passive mechanism capable of generating a potential energy field, and therefore restoring forces, around a cyclic trajectory which fits closely with a standard human gait. The mechanism uses two sets of cable-and-pulley systems to relate the elongation of two compliant cables to the angular positions of a user's hip and knee articulations. Designing a lightweigh... View full abstract»

• ### Context-Aware Depth and Pose Estimation for Bronchoscopic Navigation

Publication Year: 2019, Page(s): 1
| | PDF (1580 KB)

Endobronchial intervention is increasingly used as a minimally invasive means of lung intervention. Vision-based localisation approaches are often sensitive to image artefacts in bronchoscopic videos. In this paper, a robust navigation system based on a context-aware depth recovery approach for monocular video images is presented. To handle the artefacts, a conditional generative adversarial learn... View full abstract»

• ### Robust Pose-Graph SLAM using Absolute Orientation Sensing

Publication Year: 2019, Page(s): 1
| | PDF (3028 KB)

It is known that in the SLAM problem when a robot's orientation is known, the estimation of history of its poses can be formulated as a standard linear least squares problem. In this work, we exploit this property of SLAM to develop a robust pose-graph SLAM framework that uses absolute orientation sensing. Our contribution are as follows; (i) we show that absolute orientation can be estimated usin... View full abstract»

• ### Caterpillar-inspired Crawling Robot using Both Compression and Bending Deformations

Publication Year: 2019, Page(s): 1
| | PDF (3922 KB)

Multimodal deformations of soft materials such as compression and bending are a commonplace event on soft-bodied animals (e.g., worms) and soft-bodied robots. Usually, such deformation modes are separately analyzed or constrained to decrease the degrees of freedom when one design motion of the soft-bodied robots. This paper proposes to use multiple deformation modes and presents a highly deformabl... View full abstract»

• ### Modeling Grasp Type Improves Learning-Based Grasp Planning

Publication Year: 2019, Page(s): 1
| | PDF (5599 KB)

Different manipulation tasks require different types of grasps. For example, holding a heavy tool like a hammer requires a multi-fingered power grasp offering stability, while holding a pen to write requires a multi-fingered precision grasp to impart dexterity on the object. In this paper, we propose a probabilistic grasp planner that explicitly models grasp type for planning high-quality precisio... View full abstract»

• ### Safe Navigation with Human Instructions in Complex Scenes

Publication Year: 2019, Page(s): 1
| | PDF (1976 KB)

In this paper, we present a robotic navigation algorithm with natural language interfaces, which enables a robot to safely walk through a changing environment with moving persons by following human instructions such as "go to the restaurant and keep away from people". We first classify human instructions into three types: the goal, the constraints, and uninformative phrases. Next, we provide groun... View full abstract»

• ### Bundled Wire Drive: Proposal and Feasibility Study of a Novel Tendon-Driven Mechanism Using Synthetic Fiber Ropes

Publication Year: 2019, Page(s): 1
| | PDF (4475 KB)

This paper proposes a new wire-driven mechanism in order to relay many ropes very simply and compactly. Ropes pass through in a joint while bundled. Synthetic fiber rope can slide and twist, exploiting its low friction coefficient. In order to use this mechanism, it is necessary to investigate the influence of sliding on tension transmission efficiency and rope strength. The results of this study ... View full abstract»

• ### Chance-Constrained Collision Avoidance for MAVs in Dynamic Environments

Publication Year: 2019, Page(s): 1
| | PDF (1165 KB)

Safe autonomous navigation of micro air vehicles in cluttered dynamic environments is challenging due to the uncertainties arising from robot localization, sensing and motion disturbances. This paper presents a probabilistic collision avoidance method for navigation among other robots and moving obstacles, such as humans. The approach explicitly considers the collision probability between each rob... View full abstract»

• ### A Hand Combining Two Simple Grippers to Pick up and Arrange Objects for Assembly

Publication Year: 2019, Page(s): 1
| | PDF (2386 KB)

This paper proposes a novel robotic hand design for assembly tasks. The idea is to combine two simple grippers - an inner gripper which is used for precise alignment, and an outer gripper which is used for stable holding. Conventional robotic hands require complicated compliant mechanisms or complicated control strategy and force sensing to conduct assemble tasks, which makes them costly and diffi... View full abstract»

## Aims & Scope

The IEEE Robotics and Automation Letters (RA-L) publishes peer-reviewed articles that provide a timely and concise account of innovative research ideas and application results, reporting significant theoretical findings and application case studies in areas of robotics and automation.

Full Aims & Scope

## Meet Our Editors

Editor-in-Chief
Allison Okamura
Department: Mechanical Engineering
Stanford University
Stanford,  California  USA 94305-4021
EiC.RA.Letters@ieee.org