Kinematics of a New 14 DOF Humanoid Biped Robot

2013 ◽  
Vol 842 ◽  
pp. 564-568
Author(s):  
Lu Min Chen ◽  
Fan Wang
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Biped Robot ◽  
Kinematic Control ◽  
Forward And Inverse Kinematics ◽  
Control Study

This paper proposes a novel architecture for a biped robot with six DOFs per leg and an active toe DOF (Degrees of Freedom). The arrangement of three successive DOFs paralleled to each other makes its inverse kinematics simple and decoupled by omitting one DOF which is unnecessary when walking. And this work presents close equations for the forward and inverse kinematics. The results can be used in the kinematic control study of the robot.

A Hybrid Self-Stressed Cable-Driven Mechanism

2008 ◽  
Author(s):  
Saeed Behzadipour
Keyword(s):  
Static Loading ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Tensile Force ◽  
Cable System ◽  
End Effector ◽  
Stiffness Analysis ◽  
Cable Length ◽  
Cable Drive ◽  
Forward And Inverse Kinematics

A new hybrid cable-driven manipulator is introduced. The manipulator is composed of a Cartesian mechanism to provide three translational degrees of freedom and a cable system to drive the mechanism. The end-effector is driven by three rotational motors through the cables. The cable drive system in this mechanism is self-stressed meaning that the pre-tension of the cables which keep them taut is provided internally. In other words, no redundant actuator or external force is required to maintain the tensile force in the cables. This simplifies the operation of the mechanism by reducing the number of actuators and also avoids their continuous static loading. It also eliminates the redundant work of the actuators which is usually present in cable-driven mechanisms. Forward and inverse kinematics problems are solved and shown to have explicit solutions. Static and stiffness analysis are also performed. The effects of the cable’s compliance on the stiffness of the mechanism is modeled and presented by a characteristic cable length. The characteristic cable length is calculated and analyzed in representative locations of the workspace.

A Model of the Human Spine: Forward and Inverse Kinematics

1992 ◽  
Author(s):  
Sunil Kumar Agrawal ◽  
Siyan Li ◽  
Glen Desmier
Keyword(s):  
Range Of Motion ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Joint Angles ◽  
Human Spine ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degrees Of Freedom ◽  
Adjacent Vertebra

Abstract The human spine is a sophisticated mechanism consisting of 24 vertebrae which are arranged in a series-chain between the pelvis and the skull. By careful articulation of these vertebrae, a human being achieves fine motion of the skull. The spine can be modeled as a series-chain with 24 rigid links, the vertebrae, where each vertebra has three degrees-of-freedom relative to an adjacent vertebra. From the studies in the literature, the vertebral geometry and the range of motion between adjacent vertebrae are well-known. The objectives of this paper are to present a kinematic model of the spine using the available data in the literature and an algorithm to compute the inter vertebral joint angles given the position and orientation of the skull. This algorithm is based on the observation that the backbone can be described analytically by a space curve which is used to find the joint solutions..

In-hand forward and inverse kinematics with rolling contact

Robotica ◽  
2017 ◽  
Vol 35 (12) ◽  
pp. 2381-2399 ◽  
Author(s):  
Lei Cui ◽  
Jie Sun ◽  
Jian S. Dai
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Rolling Contact ◽  
Moving Frame ◽  
Robot Hand ◽  
Robotic Hands ◽  
Geometric Framework ◽  
Univariate Polynomial ◽  
Forward And Inverse Kinematics ◽  
Exponential Formula

SUMMARYRobotic hands use rolling contact to manipulate a grasped object to a desired location, even when the finger and the palm linkage mechanisms lack degrees of freedom. This paper presents a systematic approach to the forward and inverse kinematics of in-hand manipulation. The moving frame method in differential geometry is integrated into the product of exponential formula to establish a pure geometric framework of the kinematics of a robot hand. The forward and inverse kinematics of a multifingered hand are obtained in terms of the joint rates and contact trajectories. A two-fingered planar robot hand and a three-fingered spatial robot hand are used to demonstrate the proposed approach. The proposed formulation amounts to solving a univariate polynomial, providing an alternative to the existing ones that require numerical integration.

scholarly journals Nonanthropomorphic exoskeleton with legs based on eight-bar linkages

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141875577 ◽  
Author(s):  
Jorge Curiel Godoy ◽  
Ignacio Juárez Campos ◽  
Lucia Márquez Pérez ◽  
Leonardo Romero Muñoz
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Main Function ◽  
Polynomial Functions ◽  
Forward And Inverse Kinematics ◽  
And Performance ◽  
The Stability ◽  
Robotic Leg ◽  
Three Degrees Of Freedom ◽  
Difficulty Walking

This article presents the principles upon which a new nonanthropomorphic biped exoskeleton was designed, whose legs are based on an eight-bar mechanism. The main function of the exoskeleton is to assist people who have difficulty walking. Every leg is based on the planar Peaucellier–Lipkin mechanism, which is a one degree of freedom linkage. To be used as a robotic leg, the Peaucellier–Lipkin mechanism was modified by including two more degrees of freedom, as well as by the addition of a mechanical system based on toothed pulleys and timing belts that provides balance and stability to the user. The use of the Peaucellier–Lipkin mechanism, its transformation from one to three degrees of freedom, and the incorporation of the stability system are the main innovations and contributions of this novel nonanthropomorphic exoskeleton. Its mobility and performance are also presented herein, through forward and inverse kinematics, together with its application in carrying out the translation movement of the robotic foot along paths with the imposition of motion laws based on polynomial functions of time.

Design and Implementation of a Binary Redundant Manipulator With Cascaded Modules1

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Emmanouil Tzorakoleftherakis ◽  
Anastasia Mavrommati ◽  
Anthony Tzes
Keyword(s):  
Computational Complexity ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Redundant Manipulator ◽  
Stable States ◽  
Design And Implementation ◽  
Serial Robot ◽  
The Subject ◽  
Forward And Inverse Kinematics ◽  
Three Degrees Of Freedom

The subject of this paper is the design and implementation of a prototype snakelike redundant manipulator. The manipulator consists of cascaded modules eventually forming a macroscopically serial robot and is powered by shape memory alloy (SMA) wires. The SMAs (NiTi) act as binary actuators with two stable states and as a result, the repeatability of the manipulator's movement is ensured, alleviating the need for complex feedback sensing. Each module is composed of a customized spring and three SMA wires which form a tripod with three degrees of freedom (DOFs). Embedded microcontrollers networked with the I2C protocol activate the actuators of each module individually. In addition, we discuss certain design aspects and propose a solution that deals with the limited absolute stroke achieved by SMA wires. The forward and inverse kinematics of the binary manipulator are also presented and the tradeoff between maneuverability and computational complexity is specifically addressed. Finally, the functionality and maneuverability of this design are verified in simulation and experimentally.

Kinematics for an Actuated Flexible n-Manifold

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Oded Medina ◽  
Amir Shapiro ◽  
Nir Shvalb
Keyword(s):  
Smooth Function ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Mathematical Framework ◽  
Two Dimensional ◽  
Rectangular Grid ◽  
Flexible Robots ◽  
Forward And Inverse Kinematics ◽  
Grid Surface

Recent years show an increasing interest in flexible robots due to their adaptability merits. This paper introduces a novel set of hyper-redundant flexible robots which we call actuated flexible manifold (AFM). The AFM is a two-dimensional hyper-redundant grid surface embedded in ℝ2 or ℝ3. Theoretically, such a mechanism can be manipulated into any continuous smooth function. We introduce the mathematical framework for the kinematics of an AFM. We prove that for a nonsingular configuration, the number of degrees of freedom (DOF) of an AFM is simply the number of its grid segments. We also show that for a planar rectangular grid, every nonsingular configuration that is also energetically stable is isolated. We show how to calculate the forward and inverse kinematics for such a mechanism. Our analysis is also applicable for three-dimensional hyper-redundant structures as well. Finally, we demonstrate our solution on some actuated flexible grid-shaped surfaces.

Kinematic Analysis of a Three-DOF Parallel Mechanism for Telescope Applications

1997 ◽  
Author(s):  
J. A. Carretero ◽  
M. Nahon ◽  
B. Buckham ◽  
C. M. Gosselin
Keyword(s):  
Kinematic Analysis ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Constraint Equations ◽  
Forward And Inverse Kinematics ◽  
Position And Orientation ◽  
Three Degree Of Freedom ◽  
Three Degrees Of Freedom

Abstract This paper presents a kinematic analysis of a three-degree-of-freedom parallel mechanism intended for use as a telescope mirror focussing device. The construction of the mechanism is first described and its forward and inverse kinematics solutions are derived. Because the mechanism has only three degrees of freedom, constraint equations must be generated to describe the inter-relationship between the six Cartesian coordinates which describe the position and orientation of the moving platform. Once these constraints are incorporated into the kinematics model, a constrained Jacobian matrix is obtained. The stiffness and dexterity properties of the mechanism are then determined based on this Jacobian matrix. The mechanism is shown to exhibit desirable properties in the region of its workspace of interest in the telescope focussing application.

Kinematics and Singularity Analysis of a 2R2T Parallel Mechanism

2015 ◽  
Author(s):  
Wei Ye ◽  
Yuefa Fang ◽  
Sheng Guo
Keyword(s):  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Design Stage ◽  
Forward Kinematics ◽  
Medical Applications ◽  
Moving Platforms ◽  
Forward And Inverse Kinematics ◽  
Displacement Group

In this paper, we focus our attention on a parallel mechanism with four identical limbs and two moving platforms that are connected by a prismatic joint. Firstly, the degrees of freedom analysis of the mechanism is conducted based on the displacement group theory. Both the two moving platforms have the ability to perform two rotational and two translational motions (2R2T). Secondly, forward and inverse kinematics of the proposed mechanism is analyzed, closed-from solutions are obtained for the forward kinematics. Finally, three types of singularity, i.e. limb singularity, actuation singularity and platform singularity of the 2R2T parallel mechanism are analyzed. No limb singularity and platform singularity is found and the actuation singularity can be avoided in the design stage. The proposed mechanism has the potential to be used in industry and medical applications.

A Novel Hydraulic Spherical Joint and Motion Analysis

2014 ◽  
Vol 971-973 ◽  
pp. 314-317
Author(s):  
Shou Long Fang ◽  
Liang Wang ◽  
Shuai Ding
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Hydraulic Drive ◽  
Spherical Joint ◽  
Compact Structure ◽  
New Type ◽  
Forward And Inverse Kinematics ◽  
Joint Mechanism ◽  
Singular Configuration ◽  
Mechanism Theory

Proposing a new type of hydraulic drive spherical joint with two degrees of freedom.The joint mechanism has the advantages of hydraulic and also can rotate with multi-degrees of freedom. Based on the mechanism theory, the forward and inverse kinematics equations are derivated and the singular configuration and workspace of the mechanism are found. The spherical joint mechanism has these characteristics: a compact structure, low coupling, large load, and the joint can complete the omni-directional output.

Kinematics of a 4-DOF Bipod Parallel Grinder

2006 ◽  
Vol 304-305 ◽  
pp. 431-435
Author(s):  
Ping Zou ◽  
J. Angeles
Keyword(s):  
Closed Form ◽  
Inverse Kinematics ◽  
Horizontal Plane ◽  
Degrees Of Freedom ◽  
Closed Form Solutions ◽  
Moving Platform ◽  
Forward And Inverse Kinematics

In this paper, a novel bipod parallel grinder with four controlled degrees of freedom is introduced. The moving platform of this 2-leg parallel grinder can always keep moving in horizontal plane by means of four-parallelogram mechanism (Π joints). The closed-form solutions of forward and inverse kinematics are derived.

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