scholarly journals Synthesis Theory and Optimum Design of Four-bar Linkage with Given Angle Parameters

2019 ◽  
Vol 10 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Lairong Yin ◽  
Long Huang ◽  
Juan Huang ◽  
Peng Xu ◽  
Xuejun Peng ◽  
...  
Keyword(s):  
High Efficiency ◽  
Synthesis Method ◽  
Point Contact ◽  
Straight Line ◽  
Synthesis Of Mechanisms ◽  
Solution Region ◽  
Straight Line Mechanism ◽  
Four Bar Linkage ◽  
The Given ◽  
Ball Point

Abstract. In this paper, a synthesis method is proposed for the 5-point-contact four-bar linkage that approximates a straight line with given angle parameters. The given parameters were the angles and the location of the Ball point. Synthesis equations were derived for a general Ball–Burmester point case, the Ball–Burmester point at an inflection pole, and the Ball point that coincided with two Burmester points, resulting in three respective groups of bar linkages. Next, taking Ball–Burmester point as the coupler point, two out of the three bar-linkage combinations were used to generate three four-bar mechanisms that shared the same portion of a rectilinear trajectory. Computation examples were presented, and nine cognate straight-line mechanisms were obtained based on the Roberts-Chebyshev theory. Considering that the given parameters were angles which was arbitrarily chosen, with the other two serving as the horizontal and vertical axes, so the solution region graphs of the solutions for three mechanism configurations were plotted. Based on these graphs, the distribution of the mechanism attributes was obtained with high efficiency. By imposing constraints, the optimum mechanism solution was straightforwardly identified by the designers. For the angular parameters prescribed in this paper, the solutions for three straight-line mechanism configurations were obtained, along with nine cognate straight-line mechanisms that shared the same portion of the rectilinear trajectory. All the fixed pivot installation locations and motion performances differed, thus providing multiple solutions to the trajectory of the synthesis of mechanisms.

A Synthesis and Optimal Method for Straight Line Mechanism with Burmester Points

2011 ◽  
Vol 199-200 ◽  
pp. 1240-1243 ◽  
Author(s):  
Lai Rong Yin ◽  
Jian You Han ◽  
Tong Yang
Keyword(s):  
Infinite Number ◽  
Line Length ◽  
Point Contacts ◽  
Optimal Method ◽  
Region Method ◽  
Straight Line ◽  
Solution Region ◽  
Straight Line Mechanism ◽  
Ball Point

When a Burmester point coincides with the Ball point at the inflection circle pole, given a fixed joint and the point, which is on the expecting straight-line and direction can synthesize an infinite number of mechanisms with coupler curve having a five-point contacts with its tangent, namely, Burmester point. Any displacement is corresponding to three four-bar straight-line linkages with the synthesis formulations given. The property charts, which include the bar ratio, the sum of bars, the relative straight-line length, mechanism types, and so on, are drawn by developing a mechanism software based on vc++6.0 with the solution region method. So the users can find out the involved linkages information intuitively, and also the aimlessness in choosing optimal mechanisms is avoided effectively.

scholarly journals Optimal synthesis of a four-bar linkage by method of controlled deviation

2004 ◽  
Vol 31 (3-4) ◽  
pp. 265-280 ◽  
Author(s):  
Radovan Bulatovic ◽  
Stevan Djordjevic
Keyword(s):  
Objective Function ◽  
Optimal Synthesis ◽  
Straight Line ◽  
Individual Comparison ◽  
Four Bar Linkage ◽  
The Given ◽  
Initial Selection ◽  
Selection Of ◽  
Process Calculation ◽  
Made In

This paper considers optimal synthesis of a four-bar linkage by method of controlled deviations. The advantage of this approximate method is that it allows control of motion of the coupler in the four-bar linkage so that the path of the coupler is in the prescribed environment around the given path on the segment observed. The Hooke-Jeeves?s optimization algorithm has been used in the optimization process. Calculation expressions are not used as the method of direct searching, i.e. individual comparison of the calculated value of the objective function is made in each iteration and the moving is done in the direction of decreasing the value of the objective function. This algorithm does not depend on the initial selection of the projected variables. All this is illustrated on an example of synthesis of a four-bar linkage whose coupler point traces a straight line, i.e. passes through sixteen prescribed points lying on one straight line. .

A frame-independent comparison metric for discrete motion sequences

2020 ◽  
Vol 234 (9) ◽  
pp. 1764-1774
Author(s):  
Ping Zhao ◽  
Yong Wang ◽  
Lihong Zhu ◽  
Xiangyun Li
Keyword(s):  
Moving Frame ◽  
Kinematic Synthesis ◽  
Reference Motion ◽  
Comparison Results ◽  
Synthesis Of Mechanisms ◽  
Rotational Part ◽  
The Difference ◽  
Four Bar Linkage ◽  
The Given ◽  
Discrete Motion

To evaluate the kinematic performance of designed mechanisms, a statistical-variance-based metric is proposed in this article to measure the “distance” between two discrete motion sequences: the reference motion and the given task motion. It seeks to establish a metric that is independent of the choice of the fixed frame or moving frame. Quaternions are adopted to represent the rotational part of a spatial pose, and the variance of the set of relative displacements is computed to reflect the difference between two sequences. With this variance-based metric formulation, we show that the comparison results of two spatial discrete motions are not affected by the choice of frames. Both theoretical demonstration and computational example are presented to support this conclusion. In addition, since the deviation error between the task motion and the synthesized motion measured with this metric is independent of the location of frames, those corresponding parameters could be excluded from the optimization algorithm formulated with our frame-independent metric in kinematic synthesis of mechanisms, and the complexity of the algorithm are hereby reduced. An application of a four-bar linkage synthesis problem is presented to illustrate the advantage of the proposed metric.

An Inverted Straight Line Mechanism for Augmenting Joint Range of Motion in a Humanoid Robot

2014 ◽  
Author(s):  
Coleman Knabe ◽  
Bryce Lee ◽  
Dennis Hong
Keyword(s):  
Range Of Motion ◽  
Peak Torque ◽  
Lookup Table ◽  
Ball Screw ◽  
Link Length ◽  
Straight Line ◽  
Robotic Joints ◽  
Straight Line Mechanism ◽  
Joint Range ◽  
Four Bar Linkage

Many robotic joints powered by linear actuators suffer from a loss of torque towards the limits of the range of motion. This paper presents the design of a fully backdriveable, force controllable rotary actuator package employed on the Tactical Hazardous Operations Robot (THOR). The assembly pairs a ball screw-driven linear Series Elastic Actuator (SEA) with a planar straight line mechanism. The mechanism is a novel inversion of a Hoeken’s four-bar linkage, using the ball screw as a linear input to actuate the rotary joint. Link length ratios of the straight line mechanism have been chosen to optimize constant angular velocity, resulting in a nearly constant mechanical advantage and peak torque of 115 [Nm] throughout the 150° range of motion. Robust force control is accomplished through means of a lookup table, which is accurate to within ±0.62% of the nominal torque profile for any load case.

The Processing Method and Discuss of Curved Surface Based on Spatial Linkage Mechanism

2011 ◽  
Vol 110-116 ◽  
pp. 899-903
Author(s):  
Li Ping Xiao ◽  
Wen Jun Wei
Keyword(s):  
Simple Structure ◽  
High Efficiency ◽  
Twist Angle ◽  
Processing Method ◽  
Ruled Surface ◽  
Line Contact ◽  
Linkage Mechanism ◽  
Linear Set ◽  
Straight Line ◽  
The Given

Compared with the free surface, the ruled surface is a linear set of parameters, and is obtained by a straight line moving in space along the curve trajectory, and tts modern processing methods are all complex and high cost. Spatial linkage mechanism has many features such as simple structure, easily control, sports continuous and so on, and the initiative crank continuous rotating drives the mechanism, at the same time, the rod length, the motion pair length or the twist angle is changed, which the cutter with start position fixed on a point of the rod main moves along the given curve, and feed moves straightly along the rod itself, so, the ruled surface was processed. The method is uncomplicated, and achieves high efficiency and high precision continuous line contact surface parts finishing, operating easily and saving cost.

scholarly journals Solution-region-based synthesis approach for selecting optimal four-bar linkages with the Ball–Burmester point

2019 ◽  
Vol 10 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Lairong Yin ◽  
Long Huang ◽  
Juan Huang ◽  
Lei Tian ◽  
Fangyi Li
Keyword(s):  
Infinite Number ◽  
Analytical Method ◽  
Point Contacts ◽  
Novel Approach ◽  
Straight Line ◽  
Special Cases ◽  
Linkage Information ◽  
Solution Region ◽  
Ball Point ◽  
Synthesis Approach

Abstract. In this paper, we present a solution-region-based synthesis approach for selecting optimal four-bar linkages with a Ball–Burmester point. We discuss both general and special cases of the Burmester point that coincide with the Ball point at the pole of the inflection circle. Given the coordinates of one fixed joint, any point on the target's straight line, and the direction of this straight line, we can synthesize an infinite number of mechanisms using a coupler curve with five-point contacts with its tangent by adopting the proposed approach. Each initial parameter corresponds to three side links that can generate three four-bar mechanisms. We generate different mechanism property charts by developing mechanism software that enables users to intuitively identify relevant linkage information and select the optimal linkage. This novel approach is a visualized analytical method for synthesizing and selecting optimal four-bar linkages with one Ball–Burmester point on its coupler curve.

Study on Synthesis of Hinged Four-Bar Linkage Straight-Line Mechanism Using Three Symmetric Points

2010 ◽  
Vol 426-427 ◽  
pp. 330-333
Author(s):  
A.P. Hu ◽  
De Jun Kong ◽  
W. Zhu
Keyword(s):  
Straight Line ◽  
Symmetric Points ◽  
Straight Line Mechanism ◽  
Four Bar Linkage

Based on the fact that symmetric coupler curve can have three different tangent points with given straight-line, the three symmetric points of coupler locus was specified, and they was made into symmetric tangent points to determine the position of instant centre method. The size of the hinged four-bar linkage straight-line mechanism is determined using the position of instant centre method. The results were shown that coupler locus curve is obtained with this approach that is approximated with the intended straight-line precisely, and the basis of this approach is simpler than other analytic approaches.

A Determinant Elimination Method for Bottleneck Assignment and Generalized Assignment Problems

2012 ◽  
Vol 239-240 ◽  
pp. 1522-1527
Author(s):  
Wen Bo Wu ◽  
Yu Fu Jia ◽  
Hong Xing Sun
Keyword(s):  
Computational Complexity ◽  
Optimization Algorithm ◽  
Assignment Problem ◽  
Numerical Experiments ◽  
High Efficiency ◽  
Synthesis Method ◽  
Assignment Problems ◽  
Generalized Assignment ◽  
The Cost ◽  
Time And Space Complexity

The bottleneck assignment (BA) and the generalized assignment (GA) problems and their exact solutions are explored in this paper. Firstly, a determinant elimination (DE) method is proposed based on the discussion of the time and space complexity of the enumeration method for both BA and GA problems. The optimization algorithm to the pre-assignment problem is then discussed and the adjusting and transformation to the cost matrix is adopted to reduce the computational complexity of the DE method. Finally, a synthesis method for both BA and GA problems is presented. The numerical experiments are carried out and the results indicate that the proposed method is feasible and of high efficiency.

SIMULATION SCHEME MODELING OF THE SUPER-SPEED TIME BUFFER

2020 ◽  
Author(s):  
А.М. САЖНЕВ ◽  
Л.Г. РОГУЛИНА
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Low Cost ◽  
Circuit Modeling ◽  
Clock Signal ◽  
Behavioral Models ◽  
Software Environment ◽  
Time Buffer ◽  
The Given ◽  
Simulation Scheme

Приводятся результаты моделирования сверхскоростного буфера тактовых сигналов, выполненного на базе арсенид-галлиевых n-канальных транзисторов в среде OrCAD и полностью отвечающего следующим требованиям: высокие технические характеристики, малые размеры, высокая частота и КПД, гибкость применения. Приведенные поведенческие модели допускают использование любой программной среды по схемотехническому моделированию. The results of simulation of an ultra-high-speed clock signal buffer based on gallium arsenide n-channel transistors in OrCAD are presented, which fully meets the following requirements: high technical characteristics, application flexibility, low cost, small size, high frequency, and high efficiency. The given behavioral models allow the use of any software environment for circuit modeling.

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