Dexterous Robotic Manipulation Research Articles

A review on modeling of flexible deformable object for dexterous robotic manipulation

In this article, we present a review on the recent advancement in flexible deformable object modeling for dexterous manipulation in robotic system. Flexible deformable object is one of the most research topics in computer graphic, computer vision, and robotic literature. The deformable models are known as the construction of object with material parameters in virtual environment to describe the deformation behavior. Existing modeling techniques and different types of deformable model are described. Various approaches of deformable object modeling have been used in robotic recognition and manipulation in order to reduce the time and cost to obtain more accurate result. In robotic manipulation, object detection, classification, and recognition of deformable objects are always a challenging problem and required as a first step to imbue the robot to able handle these deformable objects. Furthermore, the dexterity of robot control is also another essential key in handling of deformable object which its manipulation strategies need to plan intelligently for each sequence process. We also discuss some deserving direction for further research based on most current contribution.

Dexterous robotic manipulation via a dynamic sliding mode force/position control with bounded inputs

Grasping and manipulation are common robotic tasks which require to properly control the interaction forces and position of multiple robots end-effectors. In this study, the authors focus on the problem of dexterous manipulation of rigid objects by means of a cooperative robotic system. Unlike several works, they consider the more complex case when the manipulated object is not mechanically attached to the robots' end-effectors. In addition, they address the control problem of designing a control law with continuous and bounded input torques for cooperative robots in constrained motion. To guarantee a stable grasp and a fine manipulation a centralised control algorithm based on the Orthogonalisation principle and a dynamic sliding mode control is proposed. The control algorithm does not require the knowledge of the dynamic model of the robot manipulators and manipulated object for implementation. Experimental results are presented to show the good performance of the proposed controller. In addition, the stability analysis of the closed-loop dynamics is developed.

Real-time modeling and parameter approximation of dexterous garment folding by robot

One of the challenging tasks for general household robot of doing household work is to manipulate deformable objects such as garments. The improper folding procedure by the robot will cause the failures such as generating wrinkles, cause the garment to misalign and the following folding process will possibly fail. Moreover, given different types and sizes of garment, the robot should able to understand its perception and planning strategy such as the start and end position of grasping points, the trajectory for each sequence and also the completed folding procedure. This paper present a novel generic approach of real-time modeling and parameter approximation applied in the dexterous robotic manipulation of unknown garment using particle-based polygonal model with online simulation. The proposed approach is a system that can judge which of the prepared polygonal models is appropriate. The prepared model is used to simulate a crudely spread-out garment placed on the flat platform that can be recognized by vision sensor. The parameters of the garment can be approximated from the proposed model and then the folding procedure can be planned based on these parameters. Later, the robot can follow the trajectory from simulation to achieve the acceptable result in the real garment folding.

Design and Operational Elements of the Robotic Subsystem for the e.deorbit Debris Removal Mission.

This paper presents a robotic capture concept that was developed as part of the e.deorbit study by ESA. The defective and tumbling satellite ENVISAT was chosen as a potential target to be captured, stabilized, and subsequently de-orbited in a controlled manner. A robotic capture concept was developed that is based on a chaser satellite equipped with a seven degrees-of-freedom dexterous robotic manipulator, holding a dedicated linear two-bracket gripper. The satellite is also equipped with a clamping mechanism for achieving a stiff fixation with the grasped target, following their combined satellite-stack de-tumbling and prior to the execution of the de-orbit maneuver. Driving elements of the robotic design, operations and control are described and analyzed. These include pre and post-capture operations, the task-specific kinematics of the manipulator, the intrinsic mechanical arm flexibility and its effect on the arm's positioning accuracy, visual tracking, as well as the interaction between the manipulator controller and that of the chaser satellite. The kinematics analysis yielded robust reachability of the grasp point. The effects of intrinsic arm flexibility turned out to be noticeable but also effectively scalable through robot joint speed adaption throughout the maneuvers. During most of the critical robot arm operations, the internal robot joint torques are shown to be within the design limits. These limits are only reached for a limiting scenario of tumbling motion of ENVISAT, consisting of an initial pure spin of 5 deg/s about its unstable intermediate axis of inertia. The computer vision performance was found to be satisfactory with respect to positioning accuracy requirements. Further developments are necessary and are being pursued to meet the stringent mission-related robustness requirements. Overall, the analyses conducted in this study showed that the capture and de-orbiting of ENVISAT using the proposed robotic concept is feasible with respect to relevant mission requirements and for most of the operational scenarios considered. Future work aims at developing a combined chaser-robot system controller. This will include a visual servo to minimize the positioning errors during the contact phases of the mission (grasping and clamping). Further validation of the visual tracking in orbital lighting conditions will be pursued.

Analysis of on-orbit servicing technique demonstrations oninternational space station and developments

The common practice for space programs is that orbital experiments aimed at engineering applications are carried out gradually. The on-orbit servicing (OOS) programs such as refueling and additive manufacturing on International Space Station (ISS) are reviewed firstly, then the continued programs are introduced. The key techniques which constrain the engineering application are analyzed including dexterous robotic manipulator, cooperative operation, safety rendezvous and docking, space additive manufacturing and refueling for non-cooperative target. Finally, the enlightenments of OOS programs on ISS are summarized and corresponding references are brought forward based on the development status of China’s Space Station.

Touch sensing for humanoid robots

A human-like touch and feel ability is still a major challenge yet to be solved in order to accelerate robot's transition from performing routine, preplanned, tasks in structured industrial environments to creatively performing tasks in unstructured environments such as nuclear stations, war zones, underwater, outer space, healthand elder-care, or telemedicine. Due to those unsolved challenges encountered in the development of a truly human-like touch sensing and perception capability for humanoid robot hands, considerable effort is still required before achieving the point of replicating the human hand's abilities by a multi-finger robot hand able to efficiently carry on dexterous robotic manipulation operations. All these challenges provide a strong incentive for using the bio-inspired approaches to develop efficient static and dynamic touch sensing technologies for the new generation of humanoid robots.

Dexterous robotic manipulation of alert adult Drosophila for high-content experimentation.

We present a robot that enables high-content studies of alert adult Drosophila by combining operations including gentle picking, translations and rotations, characterizations of fly phenotypes and behaviors, micro-dissection or release. To illustrate, we assessed fly morphology, tracked odor-evoked locomotion, sorted flies by sex, and dissected the cuticle to image neural activity. The robot's tireless capacity for precise manipulations enables a scalable platform for screening flies’ complex attributes and behavioral patterns.

Detection and prevention of slip using sensors with different properties embedded in elastic artificial skin on the basis of previous experience

In dexterous robotic manipulation, it is essential to control the force exerted by the robot hands while grasping. This paper describes a method by which robot hands can be controlled on the basis of previous experience of slippage of objects held by the hand. We developed an anthropomorphic human scale robot hand equipped with an elastic skin in which two types of sensor are randomly embedded. One of these sensors is a piezoelectric polyvinylidenefluoride (PVDF) film which can be used for the detection of pressure changes. The other is a strain gauge which can measure static pressure. In our system, PVDF films are used to detect slipping, and strain gauges to measure stresses which are caused by normal and shear forces. The stress measured by the strain gauges is used as input data to a neural network which controls the actuators of the robot. Once slip is detected, the neural network is updated to prevent it. We show that this system can control the grasp force of the robot hand and adapt it to the weight of the object. By using this method, it was shown that robots can hold objects safely.

Measurement and Optimization of Minimally Invasive Intervention Device Design Fitness Using a Multiobjective Weighted Isotropy Index

The recent transition from multiple-port to single-port systems in minimally invasive intervention (MII) procedures has created a need for more flexible, dexterous robotic manipulation devices capable of spanning an entire surgical workspace without the risk of collateral damage. The design of such devices requires a careful balance of the mechanical complexity needed to facilitate clinical functionality and the cost of manufacturing and operating the device. This paper presents a novel metric for measuring the design fitness of kinematically redundant robotic MII devices and for optimizing them to achieve that balance. The proposed fitness metric rewards designs that are conducive to collision avoidance and energy conservation while penalizing those with exorbitant design complexities that adversely affect the economic feasibility of an MII system. The authors’ metric is used here to design a kinematically redundant, single-port MII device capable of accessing the cardiothoracic cavity through a single subxiphoid port and reaching several regions of interest, consistent with procedures such as epicardial ablation and therapeutic substance injection, with minimal physiologic disturbance. The design of this device is determined by a morphological optimization process, which searches a discrete mechanical design parameter space, consisting of linkage parts, part dimensions, and actuator types, using genetic algorithms. The execution of specific surgical maneuvers is simulated for each candidate MII device design, and the design is improved until the fitness metric is maximized. The results of this optimization study demonstrate that redesigning a 20 degree-of-freedom (DOF) MII device using the proposed metric decreased the DOF in the design by 45% while ensuring near-optimal levels of kinematic flexibility. The results also demonstrate the ability of the fitness metric to elucidate the relationship between functionality and complexity and to produce suitable device designs over a broad range of performance and cost goals. The authors conclude that this new design fitness metric, while heuristic in nature, holds the potential to improve both the clinical value and the economy of a wide variety of single-port MII devices, including those used in cardiothoracic surgery.

Exoskeletal Force-Sensing End-Effectors With Embedded Optical Fiber-Bragg-Grating Sensors

Force sensing is an essential requirement for dexterous robot manipulation. We describe composite robot end-effectors that incorporate optical fibers for accurate force sensing and estimation of contact locations. The design is inspired by the sensors in arthropod exoskeletons that allow them to detect contacts and loads on their limbs. In this paper, we present a fabrication process that allows us to create hollow multimaterial structures with embedded fibers and the results of experiments to characterize the sensors and controlling contact forces in a system involving an industrial robot and a two-fingered dexterous hand. We also briefly describe the optical-interrogation method used to measure multiple sensors along a single fiber at kilohertz rates for closed-loop force control.

Estimation of Multijoint Stiffness Using Electromyogram and Artificial Neural Network

The human arm exhibits outstanding manipulability in executing various tasks by taking advantage of its intrinsic compliance, force sensation, and tactile contact clues. By examining human strategy in controlling arm impedance, we may be able to understand underlying human motor control and develop control methods for dexterous robotic manipulation. This paper presents a novel method for estimating multijoint stiffness by using electromyogram (EMG) and an artificial neural network model. The artificial network model developed in this paper relates EMG data and joint motion data to joint stiffness. With the proposed method, the multijoint stiffness of the arm was estimated without complex calculation or specialized apparatus. The feasibility of the proposed method was confirmed through experimental and simulation results.

Real-Time Control Architecture for Sauvim

This paper provides an overview of hardware and software architecture of SAUVIM (Semi-Autonomous Underwater Vehicle for Intervention Missions) which has been developed at the Autonomous Systems Laboratory (ASL). Unlike other autonomous underwater vehicles (AUVs), SAUVIM is equipped with an electric motor-driven dexterous robotic manipulator for underwater tasks requiring physical contacts with underwater objects. The overall vehicle-manipulator system becomes a high degrees-of-freedom multi-body nonlinear dynamic system. To effectively control this complex robotic system, distributed real-time hardware architecture and modified hierarchical software architecture with Sensor Data Bus (SDB) were used. The SDB makes it possible to get a prompt response from high-level control with respect to low-level sensor data. SAUVIM Task Description Language (STDL) was also developed to increase the flexibility of the vehicle tasks. Using STDL, any modification of control software is not required for various tasks. The user can also easily describe a task with various sensor data and handle multiple actuators.