A six-component contact force measurement device based on the Stewart platform

Dai, Jian S.; Kerr, David

doi:10.1243/0954406001523696

Cited by 71 publications

(39 citation statements)

References 12 publications

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“…Through the comparison of Table II with I, it is not difficult to find that there exists a one-to-one correspondence between the decomposed joint twists for the compliance matrix (33) and the synthesized spring wrenches for the stiffness one (32). First, the corresponding elastic joints and springs in the serial and parallel realization mechanisms are parallel to each other, respectively, namely β i = α i , i = 1, .…”

Section: Numerical Examplesmentioning

confidence: 99%

“…The technique of Cartesian stiffness decomposition has been applied to the design/synthesis of robot manipulators satisfying particular force-deflection characteristics by many researchers [32]- [34], while in this section, a potential application of the proposed decomposition method is illustrated for the structural stiffness modeling of flexible links in robot manipulators.…”

Section: Application To Structural Stiffness Modelingmentioning

confidence: 99%

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The Principal Axes Decomposition of Spatial Stiffness Matrices

et al. 2015

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This paper presents an alternative decomposition of spatial stiffness matrices based on the concept of compliant axes. According to the congruence transformation of spatial stiffness, the coordinate-invariant aspects, which are referred to as the central principal components of the 6 × 6 symmetric positive semidefinite matrices, can be derived uniquely. The proposed decomposition is free from the eigenvalue problems of the 6 × 6 stiffness matrices so that both Plücker's ray and axis coordinates can be utilized to characterize the elastic system's force-deflection behavior. Hence, an arbitrary spatial stiffness matrix can be uniquely decomposed into two sets of orthogonal spring wrenches with finite and infinite pitches, respectively. The decomposed wrenches with finite pitches correspond to the stiffness' wrench-compliant axes, along which linear deformations produce only wrenches parallel to them. As a result, three torsional and three screw springs are required, at the most, to realize a given spatial stiffness. Using the principal axes decomposition, some physical appreciations, such as the center of stiffness, the wrench-compliant axes, and the correspondence of compliance and stiffness, can be derived to reveal the inherent structure of spatial stiffness in an intuitive manner. In order to verify the effectiveness of the proposed method, two numerical examples are intensively studied with comparison to the eigenscrew decomposition. In addition, a potential application of the proposed stiffness decomposition method is also provided for the structural compliance modeling of flexible links in robot manipulators.Index Terms-Center of stiffness/compliance, force-deflection behavior, spatial stiffness matrix, wrench-compliant axis.

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Section: Numerical Examplesmentioning

confidence: 99%

Section: Application To Structural Stiffness Modelingmentioning

confidence: 99%

The Principal Axes Decomposition of Spatial Stiffness Matrices

et al. 2015

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“…Dwarakanath and Dasgupta reported the design and the development of a PM-based force and torque sensor which are obtained by achieving well-conditioned transformation between the input and the output forces and satisfying the dual objective of the isotropy and the sensitivity [8]. Dai and Kerr analyzed the elastic properties of the PM-based force and torque sensor structure [9]. Frigola and Ros et al investigated the design and the development of a touch pad based on a 6-axis force sensor and proposed the solution to degrade the limitations impacting measurement accuracy [4].…”

Section: Introductionmentioning

confidence: 99%

The generalized interactive force calculation for the helmet mounted display with the 6URHS parallel manipulator

2015

2015 12th International Conference on Fuzzy Systems and Knowledge Discovery (FSKD)

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The method based on the dynamic model to calculate the generalized interactive force between the user's head and the 6URHS parallel manipulator is proposed to validate the feasibility of the active compliance control strategy in [2]. Firstly, the dynamics pertaining to arbitrary leg of the 6URHS parallel manipulator are investigated, and dynamic equations for the leg are derived. Secondly, the dynamic analysis for the sensor group which is a part of the leg and made up of a sensor and the upper part of the spherical joint is developed, and Newton equations for the sensor group are also presented. Thirdly, the relationship expressions about the driving torques of the 6URHS parallel manipulator and the sensor feedbacks are obtained by means of combining the dynamic equations for the legs with the sensor groups. Finally, based on the dynamic model of the 6URHS parallel manipulator and the relationship expressions above, the formula for calculating generalized interactive force is proposed; both simulation and experiment are implemented, simulation results show that the feasibility and the accuracy of the proposed method are better, and the practicability of the method and the performance of the active compliance control strategy are proved to be fine with the experimental results.

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“…In the past decades, contributions [1][2][3][4][5][6] were made for full-mobility parallel mechanisms and recently much interest was aroused in lowermobility parallel mechanisms [7][8][9][10][11][12]. Usually, a parallel mechanism has fixed mobility and does not have the ability to change it, resulting in limited flexibility to accommodate changes requested in the industrial environments.…”

Section: Introductionmentioning

confidence: 99%