High frequency contact accelerations convey important information that the vast majority of haptic interfaces cannot render. Building on prior work, we present an approach to haptic interface design that uses a dedicated linear voice coil actuator and a dynamic system model to allow the user to feel these signals. This approach was tested through use in a bilateral teleoperation experiment where a user explored three textured surfaces under three different acceleration control architectures: none, constant gain, and dynamic compensation. The controllers that use the dedicated actuator vastly outperform traditional position-position control at conveying realistic contact accelerations. Analysis of root mean square error, linear regression, and discrete Fourier transforms of the acceleration data also indicate a slight performance benefit for dynamic compensation over constant gain.

Summary form only given. Continuum robots are biologically-inspired by the invertebrate organisms such as octopus arms and elephant trunks. These robots with a backbone-less structure offer a superior performance in unstructured and cluttered environments such as collapsed buildings, unknown geographical terrain, holes and tunnels. This video features OctArm, a continuum robot that demonstrates its capabilities in whole arm manipulation, biologically-inspired maneuvering, and grasping. The video also depicts a 3D graphical model of OctArm in that can be rendered in real-time in Matlab's real-time workshop.

This paper introduces new analyses and algorithms which are essential for the practical implementation of continuous backbone continuum robots. Actuator length limits strongly shape the configuration or joint space of continuum manipulators, introducing couplings which are not reflected in previously published kinematic models. These unmodeled effects significantly restrict the practical application of previously established kinematic models on continuum robot hardware. This paper presents a new analysis of the effects of actuator limits on continuum robots. Based on the new understanding of the configuration space uncovered, we derive for the first time the configuration space of continuum robots when constrained by actuator length limits. These contributions are essential for effective use of a wide range of continuum robots and have been implemented and tested on two different types of continuum robots. Results and insight gained from this implementation are presented

This paper describes the results of field trials and associated testing of the OctArm series of multi-section continuous backbone "continuum" robots. This novel series of manipulators has recently (Spring 2005) undergone a series of trials including open-air and in-water field tests. Outcomes of the trials, in which the manipulators demonstrated the ability for adaptive and novel manipulation in challenging environments, are described. Implications for the deployment of continuum robots in a variety of applications are discussed

In contrast to traditional robotic manipulators composed of rigid links, a continuum manipulator is a long, continuously flexible extremity that grasps objects usingthe entire length of the trunk. OctArm, a three-section continuum manipulator composed of 9 McKibben actuators, was mounted on tracked mobile platform and teleoperated in a series of field and laboratory experiments. Results from these experiments show its ability to grasp objects of many shapes and sizes, retain a solid hold despite vibration or changes in acceleration, cradle fragile objects reliably, and operate in extreme environments. This robust featureset shows the usefulness and strong potential of these manipulators.

This paper presents new results for intuitive teleoperation of continuous backbone "continuum" robot manipulators. Continuum robots present unique challenges due to the nonintuitive (to humans) nature of their basic movements. We present a series of mappings, at both position and velocity levels, which provide human operators with a versatile and intuitive suite of options for joystick control of continuum robots. Results from implementations on two types of continuum manipulator hardware are summarized.

In this paper, we describe the design and implementation of a novel multi-section, continuous-backbone ("continuum") robot. The design is based on an innovative "hose-in-hose" concept. Its implementation is novel with respect to previous continuum robot designs in that stiffness and extension, in addition to bending, are actively controlled in each section of the robot. This requires a non-trivial extension of previously proposed kinematic models, and poses challenges for real-time control of the robot. We introduce a tangling/untangling algorithm to map between overall cable lengths and per-section cable lengths. Details of the design and its implementation are presented, along with a summary of real-time control issues and experimental results.