A scheme is developed for classifying the types of motion perceived by a humanlike robot. It is assumed that the robot receives visual images of the scene using a perspective system model. Equations, theorems, concepts, clues, etc., relating the objects, their positions, and their motion to their images on the focal plane are presented. >

http://ieeexplore.ieee.org/iel2/815/3148/00100651.pdf

Robot vision

Continuum robotics has rapidly become a rich and diverse area of research, with many designs and applications demonstrated. Despite this diversity in form and purpose, there exists remarkable similarity in the fundamental simplified kinematic models that have been applied to continuum robots. However, this can easily be obscured, especially to a newcomer to the field, by the different applications, coordinate frame choices, and analytical formalisms employed. In this paper we review several modeling approaches in a common frame and notational convention, illustrating that for piecewise constant curvature, they produce identical results. This discussion elucidates what has been articulated in different ways by a number of researchers in the past several years, namely that constant-curvature kinematics can be considered as consisting of two separate submappings: one that is general and applies to all continuum robots, and another that is robot-specific. These mappings are then developed both for the single-section and for the multi-section case. Similarly, we discuss the decomposition of differential kinematics (the robotâ??s Jacobian) into robot-specific and robot-independent portions. The paper concludes with a perspective on several of the themes of current research that are shaping the future of continuum robotics.

/pdf/design-and-kinematic-modeling-of-constant-curvature-4wrx5stlzx.pdf

Design and Kinematic Modeling of Constant Curvature Continuum Robots: A Review

Newness and distinctiveness is claimed in the features of ornamentation as shown inside the broken line circle in the accompanying representation.

Display screen or portion thereof with graphical user interface

Traditional robots have rigid underlying structures that limit their ability to interact with their environment. For example, conventional robot manipulators have rigid links and can manipulate objects using only their specialised end effectors. These robots often encounter difficulties operating in unstructured and highly congested environments. A variety of animals and plants exhibit complex movement with soft structures devoid of rigid components. Muscular hydrostats e.g. octopus arms and elephant trunks are almost entirely composed of muscle and connective tissue and plant cells can change shape when pressurised by osmosis. Researchers have been inspired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments. This paper discusses the novel capabilities of soft robots, describes examples from nature that provide biological inspiration, surveys the state of the art and outlines existing challenges in soft robot design, modelling, fabrication and control.

/pdf/soft-robotics-biological-inspiration-state-of-the-art-and-1esuws0p9g.pdf

Soft robotics: Biological inspiration, state of the art, and future research

Medical Image Computing and Computer-Assisted Intervention

A rotatable wrist connecting a gripper tool to the distal end of a continuum robot shaft. The rotatable wrist includes a wrist hub that is non-rotatably connected to the distal end of the shaft. A wrist capstan is rotatably connected to the wrist hub and non-rotatably connected to the gripper. A flexible wire loop extends through the wrist hub and partially contacts the wrist capstan. Linear movement of the flexible wire loop through the shaft of the continuum robot causes rotation of the wrist capstan due to friction between the flexible wire loop and the wrist capstan. The wrist also supports selective detachability and control of roll, pitch and roll, pitch yaw and roll according to different embodiments.

Dexterous wrists for surgical intervention

Continuum robots offer the dexterity and obstacle circumvention capabilities necessary to enable surgery in deep surgical sites. They also can enable joint-level ex situ force sensing (JEFS), which...

Joint-level force sensing for indirect hybrid force/position control of continuum robots with friction:

Hypothesis The use of a robotic manipulator with a dexterously orientable gripper will expand the ability of middle ear surgeons to perform precise tasks and access otherwise challenging anatomic regions. Background Middle ear surgery presents unique challenges because of the constrained operative space and limited access to certain anatomic regions. Methods A custom-designed robot with a sideways-reaching gripper was used to evaluate feasibility of manipulation tasks in different middle-ear anatomical zones. Reachable workspace within the middle ear, accuracy of free-space path following, and tool steadiness were compared between robotic telemanipulation and manual control. Preliminarily assessments of the robot's clinical utility included: 1) touching the round window niche, Eustachian tube orifice, and sinus tympani; 2) placing a stapes prosthesis; 3) removal of mockup diseased tissue in the sinus tympani. Results The reachable workspace in the middle ear was considerably greater with the robot as compared with manual manipulation using a Rosen needle. In a simple path-tracing task outside the ear, robotic telemanipulation was associated with significantly reduced error. Within the middle ear, the robot contributed to steadier movement, but longer task completion time. The gripper successfully placed a 4.5 mm piston prosthesis, accessed the round window niche, Eustachian tube orifice, and removed mockup disease from the sinus tympani. Conclusion This study demonstrates that robotic assistance using steerable tools allows surgeons to access challenging anatomic regions of the middle ear. Coordinated and accurate manipulation is evidenced by motion analyses and completion of feasibility tasks within the middle ear.

Steerable Robot-assisted Micromanipulation in the Middle Ear: Preliminary Feasibility Evaluation.

Rapidly deployable surgical robots pose minimal interruption to surgical workflow and require minimal setup time and equipment to support deployment. This paper explores the concept of rapid deployment through the use of in-vivo sensory information to adapt a pre-operative surgical plan and to increase robustness against registration and misalignment errors during robot deployment. Robotic insertion of cochlear implant electrode arrays is presented as a benchmark application demonstrating this concept. Two key ideas are presented within the context of this application: First, a hybrid position and admittance controller is used to define an insertion path plan that is modified based on in-vivo force measurements in order to reduce sensitivity to misalignment errors. Secondly, a new concept allowing the use of force cues to determine the onset of advance-off stylet electrode array insertion is presented. The new controller is tested with electrode insertions in both plastic models and human cadaveric specimens. The experiments show that insertion forces may be maintained or reduced compared to preplanned trajectories relying solely on the initial registration.

Force-based flexible path plans for robotic electrode insertion

Most existing exoskeletons have followed a similar design approach using articulated rigid links, despite the applications of strength augmentation or rehabilitation, which may have very different specifications. In order to address the urge for ergonomics in wearable assistive exoskeletons for rehabilitation, this paper proposed a design alternative using compliant continuum mechanisms. Design concepts were elaborated for an upper extremity exoskeleton for a shoulder joint. Design considerations were then detailed based on a general kinematics and statics model extended from previously published results. Construction, actuation and transmission schemes for a selected continuum structure were discussed and a preliminary prototype was constructed to demonstrate feasibility of the proposed idea.

/pdf/a-pilot-investigation-of-continuum-robots-as-a-design-1at08io31c.pdf

Nabil Simaan

Papers

Dexterous wrists for surgical intervention

Joint-level force sensing for indirect hybrid force/position control of continuum robots with friction:

Steerable Robot-assisted Micromanipulation in the Middle Ear: Preliminary Feasibility Evaluation.

Force-based flexible path plans for robotic electrode insertion

A pilot investigation of continuum robots as a design alternative for upper extremity exoskeletons