Design and Analysis of a 3-DOF Planar Flexure-based Parallel Mechanism with Large Motion Range

2018 ◽  
Author(s):  
Bao Yang ◽  
Chi Zhang ◽  
Hongtao Yu ◽  
Xiaolu Huang ◽  
Guilin Yang ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Motion Range ◽  
Large Motion

A 6-DOF Compliant Joints-Based Precision Parallel Positioner System Driven by Dual Piezoelectric Actuators

2007 ◽  
Author(s):  
Wei Dong ◽  
Zhijiang Du ◽  
Lining Sun
Keyword(s):  
Parallel Mechanism ◽  
Load Capacity ◽  
Piezoelectric Actuators ◽  
Piezoelectric Ceramics ◽  
Parallel Structure ◽  
Nanometer Scale ◽  
Compliant Joints ◽  
Piezoelectric Motors ◽  
Motion Range ◽  
Large Motion

A precision compliant parallel-structure positioner is presented in this paper, which is dually driven by six piezoelectric motors and six piezoelectric ceramics respectively. This compliant system has a load capacity higher than 2 kg because the parallel mechanism is adopted as the main architecture. This system also can provide larger workspace and higher accuracy simultaneously compared with the conventional compliant positioner systems, because it perfectly integrates two kinds of piezoelectric actuators in one parallel system. The upper platform has the stroke of 10 mm in three linear motion directions and of 6 arc-degrees in three angle motion directions respectively for the adoption of piezoelectric motors as the large motion range actuators. The positioning resolution and repeatability of the upper platform is nanometer scale for the adoption of piezoelectric ceramics as the high precision actuators.

Analysis of annulus-shaped compliant pivot with series–parallel leaves

2012 ◽  
Vol 227 (5) ◽  
pp. 1090-1101 ◽  
Author(s):  
Shusheng Bi ◽  
Tao Qiao ◽  
Hongzhe Zhao ◽  
Yanbin Yao
Keyword(s):  
Accurate Approximation ◽  
Analysis Software ◽  
Element Analysis ◽  
Motion Range ◽  
Stress Prediction ◽  
Large Motion ◽  
Displacement Behavior ◽  
Load Displacement ◽  
Geometric Compatibility ◽  
Detailed Work

Annulus-shaped compliant pivot, formed by well-proportioned compliant modules between the outer ring and inner ring, can be employed in precision mechanical systems due to good performances. Especially for the multi-series leaves in one module, the annulus-shaped compliant pivot can fulfill a large displacement range without any axial drift in theory. In the design of the annulus-shaped compliant pivot, the load–displacement behavior and the stress analysis with analytical forms are important consideration. However, in the literature, there is few detailed work. In this article, a general annulus-shaped compliant pivot model formed by series–parallel leaves is first analytically established for the load–displacement behavior and the stress prediction. These calculations are based on accurate approximation of a beam flexure. Firstly, a loaded moment is decomposed into universal loads by combining the geometric compatibility condition. The stiffness accurate approximation is then analytically obtained, which provides a simple design strategy. Furthermore, the stresses in every leaf are obtained so that the annulus-shaped compliant pivot with large motion range can be actualized by stress checking. Lastly, the analytical model has been verified by commercial finite element analysis software ANSYS.

Design of Large Motion Range and Heavy Duty 2-DOF Spherical Parallel Wrist Mechanism

2013 ◽  
Vol 25 (2) ◽  
pp. 294-305 ◽  
Author(s):  
Koji Ueda ◽  
◽  
Hiroya Yamada ◽  
Hiroaki Ishida ◽  
Shigeo Hirose ◽  
...  
Keyword(s):  
Load Capacity ◽  
Heavy Duty ◽  
Universal Joint ◽  
Compact Structure ◽  
Robotic Arms ◽  
Rescue Robot ◽  
Wide Range ◽  
Spherical Parallel Mechanism ◽  
Motion Range ◽  
Large Motion

Wrist mechanisms are important elements of robotic arms because they significantly affect the arm’s handling ability. Although various wrist mechanisms have been developed to date, a mechanism with a compact structure, a wide range of motion and a large load capacity has not yet been realized. Thus, in this paper, we propose 2-DOF Spherical Parallel (2DSP) mechanism, a heavy-duty wrist mechanism with a large motion range, and clarify its features both analytically and experimentally. The 2DSP mechanism is driven by a 2-DOF spherical parallel mechanism and is supported by a universal joint located at its center. This structure allows the 2DSP mechanism to realize a large motion range and load capacity and simplifies its kinematic analysis. Based on this analysis, we clarify the design process to maximize the motion range and propose a preferable structure of passive joints from the viewpoint of load capacity and production cost. We also describe the detailed design of a 2DSP mechanism for a rescue robot we developed previously and verify the feasibility of the proposed mechanism.

Finite Element Simulations of an Inchworm Type Piezo-Driven Rotary Actuator

2014 ◽  
Vol 945-949 ◽  
pp. 1396-1399
Author(s):  
Hu Huang ◽  
Lu Fu ◽  
Hong Wei Zhao ◽  
Cheng Li Shi
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Structure Design ◽  
Finite Element Simulations ◽  
Loading Capacity ◽  
Complex Structures ◽  
Rotary Actuator ◽  
Motion Range ◽  
Large Motion ◽  
Simulation Results

The inchworm-driven actuator is an important type of piezo-driven actuators, which has high loading capacity, large motion range and high motion accuracy but involves complex structures, control and motion processes. In this paper, an inchworm type piezo-driven rotary actuator was introduced. Static and modal analyses of key units of the rotary actuator such as the clamping unit and the driving unit were carried out by finite element simulations to ensure that key units of the rotary actuator have enough strength and good dynamic characteristics. These simulation results will be helpful to improve structure design of the inchworm actuator.

scholarly journals A prototype characterization of ExoFinger, a finger exoskeleton

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110248
Author(s):  
Marco Ceccarelli ◽  
Cuauhtemoc Morales-Cruz
Keyword(s):  
Power Consumption ◽  
Efficient Solution ◽  
Experimental Characterization ◽  
Operation Performance ◽  
Finger Temperature ◽  
Motion Range ◽  
Finger Motion ◽  
Large Motion ◽  
The Given

This article presents an experimental characterization of ExoFinger, a finger exoskeleton for finger motion assistance. The exoskeletal device is analyzed in experimental lab activities that have been conducted with different users to characterize the operation performance and to demonstrate the adaptability of the proposed device. The behavior of this device is characterized in detail using sensors to measure finger motion and power consumption. Sensor measures also demonstrate the given motion assistance performance in terms of an electrical finger response and finger temperature by resulting in an efficient solution with a large motion range of a finger in assistance of recovering finger motion.

Design and Analysis of New Large-Range XY Compliant Parallel Micromanipulators

2014 ◽  
Author(s):  
Jingjun Yu ◽  
Zhenguo Li ◽  
Dengfeng Lu ◽  
Guanghua Zong ◽  
Guangbo Hao
Keyword(s):  
Matrix Models ◽  
Mirror Symmetry ◽  
Initial Model ◽  
Element Analysis ◽  
Compliance Matrix ◽  
Parasitic Motion ◽  
Motion Range ◽  
Large Motion ◽  
Symmetry Structure ◽  
Cross Axis

The need for a compliant parallel micromanipulator (CPM) providing large motion range and high precision is increasing. Existing CPMs vary in constraint configurations and therefore it is necessary to verify/compare their characteristics. This paper compares three kinds of typical over-constrained CPMs, and derives their theoretical compliance matrix models pointing out constraint characteristics of the three kinematic configurations. Then the three CPMs are analyzed with FEA (finite element analysis), and results illustrate that the theoretical compliance matrix models are close to their FEA models. Moreover, cross-axis coupling along two motion axes (X&Y), parasitic motion and compliance fluctuation of motion stages are described in details. Through analyzing the FEA results, we present an improved CPM with a mirror-symmetry structure and redundant-constraint characteristic which can effectively constrain in-plane yaw and cross-axis coupling. It is shown that the improved CPM presented in this paper has a series of merits: large motion range up to 10mm×10mm in the dimension of 311mm×311mm×24mm, small compliance fluctuation (only 37.32% of that of the initial model), a smaller cross-axis coupling (only 24.39% of that of the initial model generated by a single-axis 5mm driving), a smaller in-plane parasitic yaw (only 53.57% of that of the initial model generated by double-axis 5mm driving).

scholarly journals Analysis of a Wearable Robotic System for Ankle Rehabilitation

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 48
Author(s):  
Matteo Russo ◽  
Marco Ceccarelli
Keyword(s):  
Parallel Architecture ◽  
Robotic Rehabilitation ◽  
Ankle Motion ◽  
Walking Gait ◽  
Force Closure ◽  
Ankle Rehabilitation ◽  
Motion Range ◽  
Peculiar Motion ◽  
Large Motion

As one of the most commonly injured joints of the human body, the ankle is often subject to sprains or fractures that require motion assistance to recover mobility. Whereas physiotherapists usually perform rehabilitation in one-on-one sessions with patients, several successful robotic rehabilitation solutions have been proposed in the last years. However, their design is usually bulky and requires the patient to sit or stand in a static position. A lightweight wearable device for ankle motion assistance, the CABLEankle, is here proposed for motion ankle exercising in rehabilitation and training. The CABLEankle is based on a cable-driven S-4SPS parallel architecture, which enables motion assistance over the large motion range of the human ankle in a walking gait. The proposed mechanism design is analyzed with kinematic and static models, and the force closure workspace of the mechanism is discussed with analytical results. Finally, the feasibility of the proposed design is investigated through numerical simulations over the ankle motion range as a characterization of the peculiar motion.

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