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For intelligent robots to solve real-world tasks, they need to manipulate multiple objects, and perform diverse manipulation actions apart from rigid transfers, such as pushing and sliding. Planning these tasks requires discrete changes between actions, and continuous, collision-free paths that fulfill action-specific constraints. In this work, we propose a multi-modal path planner, named MOPL, which...
A novel Kalman filter to estimate the center of mass (COM) of a Humanoid robot is proposed. In the conventional works, COM was estimated by some methods. First one is the kinematics computation based on the mass property of the robot and the global position and attitude of the body frame, but those errors degrade the estimation accuracy. Second is the double integral of COM acceleration computed by...
This paper deals with motion planning problems for spherical rolling robots driven by a two degree of freedom pendulum. A full dynamic model for this system is first introduced. Then, assuming that the contact path is specified and the sphere moves in pure rolling mode, the full dynamic model is reduced by imposing virtual constraints. A timing control law, based on the Beta function, for tracing...
In this paper, we address the positioning problem of remote centre of motion (RCM) mechanisms with uncalibrated image feedback from a monocular camera. Nowadays, RCM mechanisms are widely used in minimally invasive robotic surgery due to their ability to distally rotate a tool around a fixed entry port; note that in most surgical applications, the tools are typically controlled by manual/teleoperated...
Our recently developed Reverse Priority (RP) redundancy resolution method is extended here to the presence of unilateral constraints. The RP method computes the solution to a stack of prioritized tasks starting from the lowest priority one, and adding iteratively the contributions of higher priority tasks. In this framework, unilateral constraints can be added efficiently, while guaranteeing also...
This paper presents the design and control of a teleoperated robotic system for dexterous micromanipulation tasks at the meso-scale, specifically open microsurgery. Robotic open microsurgery is an unexplored yet potentially a high impact area of surgical robotics. Microsurgical operations, such as microanastomosis of blood vessels and reattachment of nerve fibers, require high levels of manual dexterity...
Here we present a suite of theoretical, computational, and experimental studies culminating in the first aerial and aquatic capable insect-scale robot. We develop a computational fluid dynamics (CFD) simulation to model fluid-wing interaction in air and water. From CFD and a system dynamics analysis we predict that a multi-modal flapping strategy will enable locomotion in both air and water for a...
This paper examines the design of a parallel spring-loaded actuated linkage intended for dynamically dexterous legged robotics applications. Targeted at toe placement in the sagittal plane, the mechanism applies two direct-drive brushless dc motors to a symmetric five bar linkage arranged to power free tangential motion and compliant radial motion associated with running, leaping, and related agile...
Autonomous and semi-autonomous smoothly interruptible trajectories are developed which are highly suitable for application in tele-operated mobile robots, operator on-board military mobile ground platforms, and other mobility assistance platforms. These trajectories will allow a navigational system to provide assistance to the operator in the loop, for purpose built robots or remotely operated platforms...
Controlling a robotic gripper to handle objects in different sizes and shapes in real-time is a complex task. The challenge is to adapt and position the gripper according to a target object. In this work, by considering a three fingered robotic gripper with a finger structure similar to that of human finger, we study the positioning of fingers in a gripper in the two dimensional plane. Using an inverse...
The 4-SPxyzS/Sxyz parallel bionic joint, which is driven by group of four pneumatic artificial muscles, was built by adding constraint branch. The dominant equation of the inverse kinematics solution was obtained. To solve the direct kinematics problem, a BP neural network is established by considering some special outputs (i.e. length of the driving branch) of the inverse kinematics solution as the...
This paper presents LIGHTarm, a passive gravity compensated exoskeleton for upper-limb rehabilitation suitable for the use both in the clinical environment and at home. Despite the low-cost and not actuated design, LIGHTarm aims at providing remarkable back-drivability in wide portions of the upper-limb workspace. The weight-support and back-drivability features are experimentally investigated on...
Omni-directional Wheeled Mobile Robots (Omni-WMR) are holonomic system able to move sideways. They have locomotive advantage and are widely deployed in a larger range of application fields, especially in narrowly constrained service-styled manufacturing industries. To ensure smooth motion and full development of locomotive advantages, motion planning draws great attention. Thanks to the mechanism...
This paper presents a recursive and parallel formulation for the dynamics simulation of large articulated robotic systems based on the Hamilton's canonical equations. Although Hamilton's canonical equations exhibit many advantageous features compared to their acceleration based counterparts, it appears that there is a lack of dedicated parallel algorithms for multi-rigid body dynamics simulation based...
Many stroke patients have impaired arm and hand function. Distal arm and hand devices may support functional use of the upper extremity in activities in daily life. The present study assessed the direct effects of a passive dynamic wrist and hand orthosis on hand and arm movements during the performance of a reach and grasp task in ten mildly to moderately impaired chronic stroke patients. The use...
The main goal of this study is to present preliminary results on the effects of combined transcranial direct current stimulation and wrist robot-assisted therapy in subacute stroke patients. Twelve subacute stroke patients participated in the study and were randomly assigned to the experimental (real stimulation on the affected hemisphere) or control group (sham stimulation). Clinical scales were...
This paper describes the anatomical design of a novel wrist therapy device. The device automatically adjusts to the size of the wearer's wrist and is designed so it only applies a torque about the wrist joint, avoiding any uncontrolled interaction forces which commonly occur with standard rotary joint exoskeletons. The device will also adapt for any wrist misalignment that occurs during donning of...
Double rigid bodies model of a free-falling cat's rotation has been widely accepted, through the further analysis of this model the paper designed a 3-DOF hinge joint in order to realize the rotation of a free-floating space robot under the condition of weightlessness. Based on the law of linear momentum and angular momentum conservation, general kinematics model of the space robot was established...
The development of skills in human infants sometimes proceeds so-called U-shaped form, an sequence of disappearance and reappearance of a skill, which has been reported in [1] for pre-reaching to balls presented to infants of early age. We use Goal Babbling, a computational model for exploratory learning of motor skills, to model this U-shaped learning dynamics and furthermore also the qualitative...
This paper considers the problem of tracking reference trajectories for systems defined on matrix Lie Groups. Both the reference system (exosystem) and controlled system have states on the same matrix Lie group, with the exosystem having constant velocity. The measurements are associated with a group action on a homogeneous space of the state space and can be thought of as measured partial relative...
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