A spherical parallel three degrees-of-freedom robot for ankle-foot neuro-rehabilitation

Malosio, Matteo; Negri, Simone; Pedrocchi, Nicola; Vicentini, Federico; Caimmi, Marco; Tosatti, Lorenzo Molinari

doi:10.1109/embc.2012.6346684

Cited by 44 publications

(23 citation statements)

References 11 publications

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“…Gosselin and Hamel built a famous camera-orienting device called "The agile eye" using the 3-RRR spherical parallel mechanism (SPM) in 1994 [28]. Malosio took advantage of the ergonomic feature of the 3-RRR SPM to develop a robotic system meeting ankle-foot rehabilitation requirements [29].…”

Section: Mechanismsmentioning

confidence: 99%

Real-time solution of the forward kinematics for a parallel haptic device using a numerical approach based on neural networks

et al. 2015

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This paper proposes a neural network (NN)-based approach to solve the forward kinematics of a 3-RRR spherical parallel mechanism designed for a haptic device. The proposed algorithm aims to remarkably speed up computation to meet the requirement of highfrequency rendering for haptic display. To achieve high accuracy, the workspace of the haptic device is divided into smaller subspaces. The proposed algorithm contains NNs of two different precision levels: a rough estimation NN to identify the index of the subspace and several precise estimation networks with expected accuracy to calculate the forward kinematics. For continuous motion, the algorithm structure is further simplified to save internal memory and increase computing speed, which are critical for a haptic device control system running on an embedded platform. Compared with the mostly used Newton-Raphson method, the proposed algorithm and its simplified version greatly increase the calculation speed by about four times and 10 times, respectively, while achieving the same accuracy level. The proposed approach is of great significance for solving the forward kinematics of parallel mechanism used as haptic devices when high update frequency is needed but hardware resources are limited.

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Section: Mechanismsmentioning

confidence: 99%

Real-time solution of the forward kinematics for a parallel haptic device using a numerical approach based on neural networks

et al. 2015

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“…Among the spherical PKMs belonging to the first class, one of the most popular is the agile eye, which was firstly proposed by Gosselin and was then also adopted by others [2][3][4][5][6][7]. Its structure is presented in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Kinematics Analysis of a Class of Spherical PKMs by Projective Angles

Legnani

Fassi

2018

Robotics

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This paper presents the kinematics analysis of a class of spherical PKMs Parallel Kinematics Machines exploiting a novel approach. The analysis takes advantage of the properties of the projective angles, which are a set of angular conventions of which their properties have only recently been presented. Direct, inverse kinematics and singular configurations are discussed. The analysis, which results in the solution of easy equations, is developed at position, velocity and acceleration level.

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“…in medical and industrial robotics, flight and automobile simulators, mechatronic systems [1]- [5]. Among numerous types of parallel manipulators, spherical parallel manipulators (SPMs) can be applied for designing orientation wrist platforms for industrial robot end effectors, solar or parabolic antenna orientation systems, medical and rehabilitation robots [6]- [9]. A special case of a three degree-of-freedom (3-DOF) SPM with revolute joints (RRR type) named Agile Eye is proposed in [10] for designing a novel camera orientation system.…”

Section: Introductionmentioning

confidence: 99%

“…Minimum-time trajectory planning and real-time control of a special five-bar parallel robot is presented in [37]. Even though low-level PID control has been applied to different types of SPMs (see, e.g., [9], [38]), to the best of our knowledge no results have been reported on the application of numerical optimal control methods to these systems. This paper presents a novel framework for generating optimal actuator trajectories for an SPM system with revolute joints, actuated by servomotors with default internal position control settings.…”

Section: Introductionmentioning

confidence: 99%

Numerical Optimal Control of a Spherical Parallel Manipulator Based on Unique Kinematic Solutions

Shintemirov

Niyetkaliyev

Rubagotti

2015

IEEE/ASME Trans. Mechatron.

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Abstract-This paper presents a framework for generating optimal motor trajectories for a spherical parallel manipulator (SPM) with revolute joints, actuated by servomotors with default internal position control settings. The proposed framework consists of three phases. First, an approach to obtain unique forward kinematics is introduced, in order to relate the angular positions of the servomotors to the orientation of the SPM top mobile platform. Then, a configuration space for the SPM is defined by using numerical procedures, in order to guarantee the absence of singularities and of collisions between links during the motion of the manipulator. Finally, reference trajectories of the servomotors are defined via convex optimization. These trajectories determine an optimal evolution of the SPM motion, based on configuration space and original servomotor dynamics. The proposed strategy is experimentally demonstrated on a prototype of Agile Wrist SPM with three servomotors.

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A spherical parallel three degrees-of-freedom robot for ankle-foot neuro-rehabilitation

Cited by 44 publications

References 11 publications

Real-time solution of the forward kinematics for a parallel haptic device using a numerical approach based on neural networks

Real-time solution of the forward kinematics for a parallel haptic device using a numerical approach based on neural networks

Kinematics Analysis of a Class of Spherical PKMs by Projective Angles

Numerical Optimal Control of a Spherical Parallel Manipulator Based on Unique Kinematic Solutions

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