Static Balancing of Tensegrity Mechanisms

2006 ◽  
Vol 129 (3) ◽  
pp. 295-300 ◽  
Author(s):  
Marc Arsenault ◽  
Clément M. Gosselin
Keyword(s):  
Degree Of Freedom ◽  
Static Balancing ◽  
Equilibrium Configurations ◽  
Balancing Conditions ◽  
Three Degree Of Freedom

The computation of the equilibrium configurations of tensegrity mechanisms is often a very tedious task even for relatively simple architectures. However, it has been observed that the complexity of this problem is significantly reduced when gravitational loads are compensated with the use of static balancing techniques. In this work, the general static balancing conditions are adapted for the case of tensegrity mechanisms. Afterward, the modified conditions are applied to two new spatial three-degree-of-freedom tensegrity mechanisms.

Static Balancing of Tensegrity Mechanisms

2005 ◽  
Author(s):  
Marc Arsenault ◽  
Cle´ment M. Gosselin
Keyword(s):  
Degree Of Freedom ◽  
Static Balancing ◽  
Equilibrium Configurations ◽  
Balancing Conditions ◽  
Three Degree Of Freedom

The computation of the equilibrium configurations of tensegrity mechanisms is often a very tedious task even for relatively simple architectures. However, it has been observed that the complexity of this problem is significantly reduced when gravitational loads are compensated with the use of static balancing techniques. In this work, the general static balancing conditions are adapted for the case of tensegrity mechanisms. Afterwards, the modified conditions are applied to two new spatial three-degree-of-freedom tensegrity mechanisms.

Static Balancing of Spatial and Planar Parallel Manipulators With Prismatic Actuators

1998 ◽  
Author(s):  
Marc Leblond ◽  
Clément M. Gosselin
Keyword(s):  
Parallel Manipulators ◽  
Geometric Interpretation ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Static Balancing ◽  
Inertial Parameters ◽  
Dimensional Parameters ◽  
Balancing Conditions ◽  
Static Conditions ◽  
Planar Parallel Manipulators

Abstract In this paper, the static balancing of existing spatial and planar parallel manipulators by the addition of balancing elements is addressed. Static balancing is defined here as the set of conditions on manipulator dimensional and inertial parameters which, when satisfied, ensure that the weight of the links does not produce any force (or torque) at the actuators for any configuration of the manipulator, under static conditions. These conditions are derived here for spatial six-degree-of-freedom parallel manipulators and it is shown that planar three-degree-of-freedom parallel manipulators can be treated as a particular case of the spatial 6-dof mechanisms. The static balancing conditions associated with planar mechanisms can therefore easily be found, but are not given here because of space limitations. A brief geometric interpretation of the balancing conditions which are associated with statically balanced spatial mechanisms is then carried out. It is shown that balancing is generally possible even when the dimensional parameters are imposed, which is a useful property since dimensional parameters are usually obtained from kinematic design or optimization. Finally, examples of balanced planar and spatial parallel manipulators are given. Static balancing leads to considerable reduction in the actuator forces (or torques), which in turn leads to less powerful actuators and more efficient designs. Moreover, the possibility of balancing existing systems by introducing additional elements, as demonstrated here, is of interest for retrofitting existing parallel mechanisms.

scholarly journals Development of a Compound Speckle Interferometer for Precision Three-Degree-of-Freedom Displacement Measurement

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1828
Author(s):  
Hung-Lin Hsieh ◽  
Bo-Yen Sun
Keyword(s):  
Speckle Interferometry ◽  
Degree Of Freedom ◽  
Heterodyne Interferometry ◽  
Beam Splitting ◽  
Speckle Interferometer ◽  
Real World Applications ◽  
Three Degree Of Freedom ◽  
Contact Displacement ◽  
Displacement Measurements ◽  
Measurement Capabilities

In this study, a compound speckle interferometer for measuring three-degree-of-freedom (3-DOF) displacement is proposed. The system, which combines heterodyne interferometry, speckle interferometry and beam splitting techniques, can perform precision 3-DOF displacement measurements, while still having the advantages of high resolution and a relatively simple configuration. The incorporation of speckle interferometry allows for non-contact displacement measurements by detecting the phase of the speckle interference pattern formed from the convergence of laser beams on the measured rough surface. Experiments were conducted to verify the measurement capabilities of the system, and the results show that the proposed system has excellent measurement capabilities suitable for future real-world applications.

scholarly journals Analytical Investigation on Torque of Three-Degree-of-Freedom Electromagnetic Actuator for Image Stabilization

2021 ◽  
Vol 11 (15) ◽  
pp. 6872
Author(s):  
Chien-Sheng Liu ◽  
Yi-Hsuan Lin ◽  
Chiu-Nung Yeh
Keyword(s):  
Power Efficiency ◽  
Rotation Angle ◽  
Analytical Investigation ◽  
Degree Of Freedom ◽  
Electromagnetic Actuator ◽  
3D Fem ◽  
Image Stabilization ◽  
Large Rotation ◽  
Spherical Motor ◽  
Three Degree Of Freedom

In keeping with consumers’ preferences for electromagnetic motors of ever smaller power consumption, it is necessary to improve the power efficiency of the electromagnetic motors used in unmanned aerial vehicles and robots without sacrificing their performance. Three-degree-of-freedom (3-DOF) spherical motors have been developed for these applications. Accordingly, this study modifies the 3-DOF spherical motor proposed by Hirata’s group in a previous study (Heya, A.; Hirata, K.; Niguchi, N., Dynamic modeling and control of three-degree-of-freedom electromagnetic actuator for image stabilization, IEEE Transactions on Magnetics 2018, 54, 8207905.) to accomplish a 3-DOF spherical motor for camera module with higher torque output in the large rotation angle. The main contribution of this study is to improve the static torque in the X- and Y-axes with an improved electromagnetic structure and a particular controlling strategy. In the structural design, eight symmetrical coils with specific coil combination are used instead of conventional four symmetrical coils. In this study, the development of the proposed 3-DOF spherical motor was constructed and verified by using a 3D finite-element method (3D FEM). The simulation results show that the proposed 3-DOF spherical motor has higher torque output in the large rotation angle when compared to the original 3-DOF spherical motor.

Three-Degree-of-Freedom Parallel Robot Arm

2006 ◽  
Author(s):  
Martin Hosek ◽  
Michael Valasek ◽  
Jairo Moura
Keyword(s):  
Parallel Robot ◽  
Degree Of Freedom ◽  
Motion Path ◽  
Angular Orientation ◽  
Robot Arm ◽  
Flat Panel Display ◽  
End Effector ◽  
Cluster Tools ◽  
Manufacturing Applications ◽  
Three Degree Of Freedom

This paper presents single- and dual-end-effector configurations of a planar three-degree of freedom parallel robot arm designed for automated pick-place operations in vacuum cluster tools for semiconductor and flat-panel-display manufacturing applications. The basic single end-effector configuration of the arm consists of a pivoting base platform, two elbow platforms and a wrist platform, which are connected through two symmetric pairs of parallelogram mechanisms. The wrist platform carries an end-effector, the position and angular orientation of which can be controlled independently by three motors located at the base of the robot. The joints and links of the mechanism are arranged in a unique geometric configuration which provides a sufficient range of motion for typical vacuum cluster tools. The geometric properties of the mechanism are further optimized for a given motion path of the robot. In addition to the basic symmetric single end-effector configuration, an asymmetric costeffective version of the mechanism is derived, and two dual-end-effector alternatives for improved throughput performance are described. In contrast to prior attempts to control angular orientation of the end-effector(s) of the conventional arms employed currently in vacuum cluster tools, all of the motors that drive the arm can be located at the stationary base of the robot with no need for joint actuators carried by the arm or complicated belt arrangements running through the arm. As a result, the motors do not contribute to the mass and inertia properties of the moving parts of the arm, no power and signal wires through the arm are necessary, the reliability and maintenance aspects of operation are improved, and the level of undesirable particle generation is reduced. This is particularly beneficial for high-throughput applications in vacuum and particlesensitive environments.

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