TriM: An Ultra-Accurate High-Speed Six Degree-of-Freedom Manipulator Using Planar Stepper Motors

2007 ◽  
Vol 51 (2) ◽  
pp. 137-157 ◽  
Author(s):  
P. Krishnamurthy ◽  
F. Khorrami
Keyword(s):  
High Speed ◽  
Degree Of Freedom ◽  
Stepper Motors ◽  
Six Degree Of Freedom

scholarly journals Development of six-degree of freedom strapdown terrestrial INS algorithm

2005 ◽  
Vol 2 (1) ◽  
pp. 155-165
Author(s):  
Baghdad Science Journal
Keyword(s):  
Real Time ◽  
High Speed ◽  
Degree Of Freedom ◽  
The Real ◽  
Six Degree Of Freedom

Many of accurate inertial guided missilc systems need to use more complex mathematical calculations and require a high speed processing to ensure the real-time opreation. This will give rise to the need of developing an effcint

Behavioral Stereotypes and Control Design Strategies for a Six-Degree-of-Freedom “Walking” Vehicle

1984 ◽  
Vol 28 (6) ◽  
pp. 492-496 ◽  
Author(s):  
Dennis B. Beringer ◽  
George R. Gruetzmacher ◽  
Naomi Swanson
Keyword(s):  
High Speed ◽  
Degree Of Freedom ◽  
Design Strategies ◽  
Foot Placement ◽  
Task Requirements ◽  
Turn Radius ◽  
Single Controller ◽  
Six Degree Of Freedom ◽  
And Control ◽  
Multiple Task

The problems posed by control of “walking” six-degree-of-freedom vehicles vary with specific task requirements. Different strategies are required for cruising “supervisory” control and precision foot placement. These, along with anthropometric and stereotypic considerations, directly affect the design of the manually operated controls and the degree to which multiple-axis/multiple-task integration can be achieved within a single controller. Systems that allow turn radius to be set in the absence of vehicle movement are best for planning and execution of slow close maneuvering while systems summing velocity vectors seem most advantageous for relatively high-speed cruise conditions.

Cage Instabilities in Cylindrical Roller Bearings

2004 ◽  
Vol 126 (4) ◽  
pp. 681-689 ◽  
Author(s):  
Niranjan Ghaisas ◽  
Carl R. Wassgren ◽  
Farshid Sadeghi
Keyword(s):  
High Speed ◽  
Roller Bearing ◽  
Degree Of Freedom ◽  
Stable Motion ◽  
Roller Bearings ◽  
Light Load ◽  
Cylindrical Roller Bearing ◽  
Six Degree Of Freedom ◽  
Cylindrical Roller ◽  
Inner Race

A six-degree-of-freedom model was developed and used to simulate the motion of all elements in a cylindrical roller bearing. Cage instability has been studied as a function of the roller-race and roller-cage pocket clearances for light-load and high-speed conditions. The effects of variation in inner race speed, misalignment, cage asymmetry, and varying size of one of the rollers have been investigated. In addition, three different roller profiles have been used to study their impact on cage dynamics. The results indicate that the cage exhibits stable motion for small values of roller-race and roller-cage pocket clearances. A rise in instability leads to discrete cage-race collisions with high force magnitudes. Race misalignment leads to a rise in instability for small roller-cage pocket clearances since skew control is provided by the sides of the cage pocket. One roller of larger size than the others causes inner race whirl and leads to stable cage motion for small roller-race clearances without any variation in roller-cage pocket clearance. Cage asymmetry and different roller profiles have a negligible impact on cage motion.

Nonlinear Analysis on Hunting Stability for High-Speed Railway Vehicle Trucks on Curved Tracks

2004 ◽  
Vol 127 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Sen-Yung Lee ◽  
Yung-Chang Cheng
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Degree Of Freedom ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Hunting Stability ◽  
Six Degree Of Freedom ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a ten-degree-of-freedom truck system, considering the lateral displacement, the vertical displacement, the roll and yaw angles of the each wheelset, and the lateral displacement and yaw angle of the truck frame, moving on curved tracks, are derived in completeness. To illustrate the accuracy of the analysis, the limiting cases are examined. The influences of the suspension parameters, including those losing in the six-degree-of-freedom system, on the critical hunting speeds evaluated via the linear and nonlinear creep models, respectively, are studied and compared.

scholarly journals Design and kinematics analysis of a novel six-degree-of-freedom serial humanoid torso

2018 ◽  
Vol 15 (1) ◽  
pp. 172988141774812 ◽  
Author(s):  
Tao Li ◽  
Peng Yao ◽  
Minzhou Luo ◽  
Zhiying Tan ◽  
Meiling Wang ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Humanoid Robots ◽  
Degree Of Freedom ◽  
Chaos Optimization ◽  
Workspace Analysis ◽  
Forward Kinematic ◽  
Six Degree Of Freedom

This article presents a bioinspired humanoid torso which is supposed to be used as the trunk for humanoid robots. It can effectively mimic motions of human torso with high degrees of freedom, and it has high stiffness and easy-to-control features. The main structure of the proposed torso is a six-degree-of-freedom serial mechanism with twist angles that are not equal to 0, π/2 or π and zero-length links. Forward kinematic and workspace analysis based on Denavit–Hartenberg and Monte Carlo methods have been formulated to analyze the feasibility of this structure. In addition, a hybrid method combing the large-scale regularity search capabilities of chaos optimization and the quasi-Newton method with relatively high-speed convergence has been proposed to analyze inverse kinematics. Simulations are carried out with the aim to validate the correctness and efficiency of this method for studying the inverse kinematics.

DYNAMIC STABILITY OF FOILBORNE HYDROFOIL/SWATH WITH ANHEDRAL FOIL CONFIGURATION

2017 ◽  
Vol 159 (B2) ◽  
Author(s):  
S Williams ◽  
S Brizzolara
Keyword(s):  
Vehicle Dynamics ◽  
High Speed ◽  
Degree Of Freedom ◽  
Design Criteria ◽  
Vehicle Stability ◽  
Configuration Design ◽  
Stability Criteria ◽  
Preliminary Assessment ◽  
Displacement Mode ◽  
Six Degree Of Freedom

The hybrid hydrofoil/SWATH (Small Waterplane Area Twin Hull) designed and patented by Stefano Brizzolara, is a novel vehicle that is optimized to operate in both a high-speed foilborne mode and a displacement mode. The deployable hydrofoils on the vehicle take on a unique four surface piercing anhedral foil configuration. This foilborne design had previously undergone only preliminary assessment of stability characteristics. A six degree of freedom model of the foilborne vehicle dynamics is introduced as a framework to study vehicle stability and maneuvering. Stability criteria derived from multiple linearized models of the vehicle dynamics are compared to the six degree of freedom results in both the vertical and horizontal planes. Foil configuration design criteria are developed for pitch equilibrium, pitch stability, and directional stability.

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