scholarly journals Isotropic Design of Tendon-Driven Manipulators

1996 ◽  
Vol 118 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Yeong-Jeong Ou ◽  
Lung-Wen Tsai
Keyword(s):  
Necessary Conditions ◽  
Degree Of Freedom ◽  
Mechanical Transmission ◽  
Force Distribution ◽  
Static Force ◽  
Design Equation ◽  
Force Analysis ◽  
Transmission Characteristics ◽  
Transmission Structure ◽  
Tendon Force

This paper deals with the synthesis of mechanical transmission structures for tendon-driven manipulators. Based on static force analysis, necessary conditions are developed for the synthesis of tendon-driven manipulators with isotropic transmission characteristics. It is shown that an n degree-of-freedom (dof) manipulator will possess the isotropic transmission characteristics, if it satisfies two isotropic conditions. Furthermore, a design equation is derived for the construction of isotropic transmission structure matrices and a three-dof spatial manipulator is synthesized to demonstrate the methodology. It is shown that the isotropic design leads to a more uniform tendon force distribution.

Theory of Isotropic Transmission for Tendon-Driven Manipulators

1994 ◽  
Author(s):  
Yeong-Jeong Ou ◽  
Lung-Wen Tsai
Keyword(s):  
General Theory ◽  
Power Transmission ◽  
Degree Of Freedom ◽  
Mechanical Power ◽  
Force Distribution ◽  
Static Force ◽  
Force Transmission ◽  
Transmission Characteristics ◽  
End Effector ◽  
Transmission Structure

Abstract This paper deals with the synthesis of the mechanical power transmission structure in tendon-driven manipulators. Based on the analysis of static force transmission from the actuator space to the end-effector space, a general theory is developed for the synthesis of tendon-driven manipulators with isotropic transmission characteristics. It is shown that an n-dof (degree of freedom) manipulator can possess these characteristics if it is made up of n+1 or 2n tendons and if its link lengths and pulley sizes are designed according to two equations of constraint. Two examples are used to demonstrate the theory. It is also shown that manipulators with an isotropic transmission structure do have more uniform force distribution among their tendons.

Direct Differential Kinematics of Hybrid-Chain Manipulators Including Singularity and Stability Analyses

1994 ◽  
Vol 116 (2) ◽  
pp. 614-621 ◽  
Author(s):  
Yong-Xian Xu ◽  
D. Kohli ◽  
Tzu-Chen Weng
Keyword(s):  
Stability Index ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Static Force ◽  
Force Analysis ◽  
Kinematic Singularity ◽  
Numerical Examples ◽  
Transformation Matrices ◽  
Unstable Configuration ◽  
Direct Kinematics

A general formulation for the differential kinematics of hybrid-chain manipulators is developed based on transformation matrices. This formulation leads to velocity and acceleration analyses, as well as to the formation of Jacobians for singularity and unstable configuration analyses. A manipulator consisting of n nonsymmetrical subchains with an arbitrary arrangement of actuators in the subchain is called a hybrid-chain manipulator in this paper. The Jacobian of the manipulator (called here the system Jacobian) is a product of two matrices, namely the Jacobian of a leg and a matrix M containing the inverse of a matrix Dk, called the Jacobian of direct kinematics. The system Jacobian is singular when a leg Jacobian is singular; the resulting singularity is called the inverse kinematic singularity and it occurs at the boundary of inverse kinematic solutions. When the Dk matrix is singular, the M matrix and the system Jacobian do not exist. The singularity due to the singularity of the Dk matrix is the direct kinematic singularity and it provides positions where the manipulator as a whole loses at least one degree of freedom. Here the inputs to the manipulator become dependent on each other and are locked. While at these positions, the platform gains at least one degree of freedom, and becomes statically unstable. The system Jacobian may be used in the static force analysis. A stability index, defined in terms of the condition number of the Dk matrix, is proposed for evaluating the proximity of the configuration to the unstable configuration. Several illustrative numerical examples are presented.

Direct Differential Kinematics of Hybrid-Chain Manipulators Including Singularity and Stability Analyses

1992 ◽  
Author(s):  
Yong-Xian Xu ◽  
Dilip Kohli ◽  
Tzu-Chen Weng
Keyword(s):  
Stability Index ◽  
Inverse Kinematic ◽  
Degree Of Freedom ◽  
Static Force ◽  
Force Analysis ◽  
Kinematic Singularity ◽  
Numerical Examples ◽  
Transformation Matrices ◽  
Unstable Configuration ◽  
Direct Kinematics

Abstract A general formulation for the differential kinematics of hybrid-chain manipulators is developed based on transformation matrices. This formulations leads to velocity and acceleration analyses, as well as to the formation of Jacobians for singularity and unstable configuration analyses. A manipulator consisting of n nonsymmetrical subchains with an arbitrary arrangement of actuators in the subchain is called a hybrid-chain manipulator in this paper. The Jacobian of the manipulator (called here the system Jacobian) is a product of two matrices, namely the Jacobian of a leg and a matrix M containing the inverse of a matrix Dk, called the Jacobian of direct kinematics. The system Jacobian is singular when a leg Jacobian is singular; the resulting singularity is called the inverse kinematic singularity and it occurs at the boundary of inverse kinematic solutions. When the Dk matrix is singular, the M matrix and the system Jacobian do not exist. The singularity due to the singularity of the Dk matrix is the direct kinematic singularity and it provides positions where the manipulator as a whole loses at least one degree of freedom. Here the inputs to the manipulator become dependent on each other and are locked. While at these positions, the platform gains at least one degree of freedom, and becomes statically unstable. The system Jacobian may be used in the static force analysis. A stability index, defined in terms of the condition number of the Dk matrix, is proposed for evaluating the proximity of the configuration to the unstable configuration. Several illustrative numerical examples are presented.

scholarly journals Analysis on the research method of road sense feedback in steer-by-wire system

2021 ◽  
Vol 2121 (1) ◽  
pp. 012031
Author(s):  
Chuanbin Wei ◽  
Lizhu Zhang ◽  
You Fu ◽  
Faying Xia
Keyword(s):  
Automobile Industry ◽  
Basic Structure ◽  
Steering System ◽  
Mechanical Transmission ◽  
Driving Experience ◽  
The Road ◽  
Establishment Method ◽  
Steer By Wire ◽  
Transmission Structure ◽  
Wire System

Abstract Nowadays, the automobile industry is gradually developing towards the trend of electrification and intelligence. Compared with the traditional steering system, the steer-by-wire system cancels the mechanical transmission structure, reduces the space utilization, reduces the probability of damage to the driver caused by the steering system in the collision accident, and improves the driving portability and enhances the driver’s handling experience. The road feeling feedback of steer-by-wire system has the greatest impact on the driver’s driving experience. This paper discusses the research methods of road feeling feedback of steer-by-wire system, introduces the basic structure of road feeling feedback of steer-by-wire system, the basic idea of dynamic modeling, the establishment of simulation model of road feeling feedback, and the establishment method of control strategy and simulation platform of road feeling feedback. Finally, it summarizes and prospects in order to provide basic information and perspectives for the development and research of steer-by-wire system.

scholarly journals Kinematic Synthesis of Tendon-Driven Manipulators with Isotropic Transmission Characteristics

1993 ◽  
Vol 115 (4) ◽  
pp. 884-891 ◽  
Author(s):  
Yeong-Jeong Ou ◽  
Lung-Wen Tsai
Keyword(s):  
Jacobian Matrix ◽  
Null Vector ◽  
Force Distribution ◽  
Force Transmission ◽  
Transmission Characteristics ◽  
Kinematic Synthesis ◽  
End Effector ◽  
Structure Matrix ◽  
Applied Forces ◽  
Matrix Design

This paper presents a methodology for kinematic synthesis of tendon-driven manipulators with isotropic transmission characteristics. The force transmission characteristics, from the end-effector space to the actuator space, has been investigated. It is shown that tendon forces required to act against externally applied forces are functions of the structure matrix, its null vector, and the manipulator Jacobian matrix. Design equations for synthesizing a manipulator to possess isotropic transmission characteristics are derived. It is shown that manipulators which possess isotropic transmission characteristics have much better force distribution among their tendons.

Force Analysis of Double Pitch Point Cycloid Drive with Intermediate Rolling Elements and Free Retainer

2015 ◽  
Vol 756 ◽  
pp. 29-34
Author(s):  
E.A. Efremenkov ◽  
E.E. Kobza ◽  
S.K. Efremenkova
Keyword(s):  
Performance Improvement ◽  
Wedge Angle ◽  
Force Distribution ◽  
Force Analysis ◽  
Angle Variation ◽  
Rolling Elements ◽  
Further Development

This paper illustrates the analysis of wedge angle influence on force distribution in the meshing of double pitch point cycloid drive in comparison with single pitch point cycloid drive. Double pitch point cycloid drive may provide smoother performance of transmission at starting period in consequence of wedge angle variation capabilities. Matching initial parameters it is possible to modify the wedge angle and achieve its effective value. The influence of various combinations of initial parameters on the wedge angle and retainer force was studied and presented on diagrams. Some recommendations in designing related to performance improvement are given. The obtained results can be used for further development of better designs of cycloid drives.

Velocity, Acceleration, and Static-Force Analyses of Spatial Linkages

1965 ◽  
Vol 32 (4) ◽  
pp. 903-910 ◽  
Author(s):  
J. Denavit ◽  
R. S. Hartenberg ◽  
R. Razi ◽  
J. J. Uicker
Keyword(s):  
Virtual Work ◽  
Algebraic Method ◽  
Degree Of Freedom ◽  
Static Force ◽  
Virtual Displacement ◽  
Single Loop ◽  
Loop Equation ◽  
The Matrix ◽  
Spatial Linkages

The algebraic method using 4 × 4 matrices is extended to the analysis of velocities, accelerations, and static forces in one-degree-of-freedom, single-loop, spatial linkages consisting of revolute and prismatic pairs, either singly or in combination. The methods are well suited for machine calculations and have been tested on a number of examples, one of which is presented. Velocities and accelerations are obtained by differentiation of the matrix-loop or position equation. Static forces are found by combining the method of virtual work with the matrix-loop equation to relate the virtual displacement of the load to given virtual deformations of the links.

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