We propose a framework to enable multipurpose assistive mobile robots to autonomously wipe tables to clean spills and crumbs. This problem is challenging, as it requires planning wiping actions while reasoning over uncertain latent dynamics of crumbs and spills captured via high-dimensional visual observations. Simultaneously, we must guarantee constraints satisfaction to enable safe deployment in unstructured cluttered environments. To tackle this problem, we first propose a stochastic differential equation to model crumbs and spill dynamics and absorption with a robot wiper. Using this model, we train a vision-based policy for planning wiping actions in simulation using reinforcement learning (RL). To enable zero-shot sim-to-real deployment, we dovetail the RL policy with a whole-body trajectory optimization framework to compute base and arm joint trajectories that execute the desired wiping motions while guaranteeing constraints satisfaction. We extensively validate our approach in simulation and on hardware. Video of experiments: https://youtu.be/inORKP4F3EI

We present RoboBench, a novel platform for sharing robot full-system simulations for benchmarking. The creation of this platform and benchmark suite is motivated by a need for reproducible research. A challenge in creating a full-system benchmarks are incompatibilities in software created by different groups and the difficulty of reproducing software environments. We solve this problem by using software containers, an emerging virtualization technology. RoboBench enables sharing robot software in a runnable state, capturing the software behavior of robots carrying out missions. These simulations make clear the performance impact and resource usage of programs and algorithms relative to other software involved in the mission. These containers are integrated with the CITK platform for reproducible research, which automates generation and publishing of the containers. We present an overview of the system, a description of our prototype set of benchmark missions, along with a validation study comparing the computational load profile of a mission performed on a real and simulated robot. Additionally, we present preliminary results of an overall analysis of the benchmarks in the RoboBench suite, showing where computational work is expended in robotics common robotics tasks. RoboBench is extensible, and is the first step toward a robust, quantitative approach to engineering computationally-efficient robots.

Even though research on autonomous robots and human-robot interaction accomplished great progress in recent years, and reusable soft- and hardware components are available, many of the reported findings are only hardly reproducible by fellow scientists. Usually, reproducibility is impeded because required information, such as the specification of software versions and their configuration, required data sets, and experiment protocols are not mentioned or referenced in most publications. In order to address these issues, we recently introduced an integrated tool chain and its underlying development process to facilitate reproducibility in robotics. In this contribution we instantiate the complete tool chain in a unique user study in order to assess its applicability and usability. To this end, we chose three different robotic systems from independent institutions and modeled them in our tool chain, including three exemplary experiments. Subsequently, we asked twelve researchers to reproduce one of the formerly unknown systems and the associated experiment. We show that all twelve scientists were able to replicate a formerly unknown robotics experiment using our tool chain.

This paper presents a deep learning architecture for detecting the palm and fingertip positions of stable grasps directly from partial object views. The architecture is trained using RGBD image patches of fingertip and palm positions from grasps computed on complete object models using a grasping simulator. At runtime, the architecture is able to estimate grasp quality metrics without the need to explicitly calculate the given metric. This ability is useful as the exact calculation of these quality functions is impossible from an incomplete view of a novel object without any tactile feedback. This architecture for grasp quality prediction provides a framework for generalizing grasp experience from known to novel objects.

We present a joint demonstration between the Robotics, Autonomous Systems, and Controls Laboratory (RASCAL) at UC Davis and the Columbia University Robotics Group, wherein a human-in-the-loop robotic grasping platform in the Columbia lab (New York, NY) is controlled to select and grasp an object by a C3-C4 spinal cord injury (SCI) subject in the UC Davis lab (Davis, CA) using a new single-signal, multi-degree-of-freedom surface electromyography (sEMG) human-robot interface. The grasping system breaks the grasping task into a multi-stage pipeline that can be navigated with only a few inputs. It integrates pre-planned grasps with on-line grasp planning capability and an object recognition and target selection system capable of handling multi-object scenes with moderate occlusion. Previous work performed in the RASCAL lab demonstrated that by continuously modulating the power in two individual bands in the frequency spectrum of a single sEMG signal, users were able to control a cursor in 2D for cursor to target tasks. Using this paradigm, four targets were presented in order for the subject to command the multi-stage grasping pipeline. We demonstrate that using this system, operators are able to grasp objects in a remote location using a robotic grasping platform.

There has been considerable interest in producing grasping platforms using non-invasive, low bandwidth brain computer interfaces(BCIs). Most of this work focuses on low level control of simple hands. Using complex hands improves the versatility of a grasping platform at the cost of increasing its complexity. In order to control more complex hands with these low bandwidth signals, we need to use higher level abstractions. Here, we present a user interface which allows the user to combine the speed and convenience of offline preplanned grasps with the versatility of an online planner. This system incorporates a database of pre-planned grasps with the ability to refine these grasps using an online planner designed for arbitrarily complex hands. Only four commands are necessary to control the entire grasping pipeline, allowing us to use a low cost, noninvasive commercial BCI device to produce robust grasps that reflect user intent. We demonstrate the efficacy of this system with results from five subjects and present results using this system to grasp unknown objects.

Underactuated compliant robotic hands exploit passive mechanics and joint coupling to reduce the number of actuators required to achieve grasp robustness in unstructured environments. Reduced actuation requirements generally serve to decrease design cost and improve grasp planning efficiency, but overzealous simplification of an actuation topology, coupled with insufficient tuning of mechanical compliance and hand kinematics, can adversely affect grasp quality and adaptability. This paper presents a computational framework for reducing the mechanical complexity of robotic hand actuation topologies without significantly decreasing grasp robustness. Open-source grasp planning software and well-established grasp quality metrics are used to simulate a fully-actuated, 24 DOF anthropomorphic robotic hand grasping a set of daily living objects. DOFs are systematically demoted or removed from the hand actuation topology according to their contribution to grasp quality. The resulting actuation topology contained 22% fewer DOFs, 51% less aggregate joint motion, and required 82% less grasp planning time than the fully-actuated design, but decreased average grasp quality by only 11%.

Grasp quality metrics which analyze the contact wrench space are commonly used to synthesize and analyze preplanned grasps. Preplanned grasping approaches rely on the robustness of stored solutions. Analyzing the robustness of such solutions for large databases of preplanned grasps is a limiting factor for the applicability of data driven approaches to grasping. In this work, we will focus on the stability of the widely used grasp wrench space epsilon quality metric over a large range of poses in simulation. We examine a large number of grasps from the Columbia Grasp Database for the Barrett hand. We find that in most cases the grasp with the most robust force closure with respect to pose error for a particular object is not the grasp with the highest epsilon quality. We demonstrate that grasps can be reranked by an estimate of the stability of their epsilon quality. We find that the grasps ranked best by this method are successful more often in physical experiments than grasps ranked best by the epsilon quality.

We propose a machine learning approach to the perception of a stable robotic grasp based on tactile feedback and hand kinematic data, which we call blind grasping. We first discuss a method for simulating tactile feedback using a soft finger contact model in Grasplt!, which is a robotic grasping simulator [10]. Using this simulation technique, we compute tactile contacts of thousands of grasps with a robotic hand using the Columbia Grasp Database [6]. The tactile contacts along with the hand kinematic data are then input to a Support Vector Machine (SVM) which is trained to estimate the stability of a given grasp based on this tactile feedback and also the robotic hand kinematics. Experimental results indicate that the tactile feedback along with the hand kinematic data carry meaningful information for the prediction of the stability of a blind robotic grasp.

This paper describes a novel underactuated robotic hand design. The hand is highly underactuated as it contains three fingers with three joints each controlled by a single motor. One of the fingers (“thumb”) can also be rotated about the base of the hand, yielding a total of two controllable degrees-of-freedom. A key component of the design is the addition of position and tactile sensors which provide precise angle feedback and binary force feedback. Our mechanical design can be analyzed theoretically to predict contact forces as well as hand position given a particular object shape