Optimization for Harmonics Reduction and Path Generation of Linkage Mechanisms

2003 ◽  
Vol 03 (03) ◽  
pp. 435-442 ◽  
Author(s):  
Zhongfan Yuan ◽  
Yi Min Wu
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
Fuzzy Theory ◽  
Present Approach ◽  
Constant Speed ◽  
Path Generation ◽  
Servo Motor ◽  
Harmonic Content ◽  
Hybrid Mechanism

The optimal design of linkage mechanisms for path generation and motions with reduced harmonic content is investigated. The designs are carried out using a two-objective optimizer based on the fuzzy theory. As an illustration, the present approach is applied to the optimization of a five-bar hybrid mechanism driven by a constant speed motor and a servo motor. The dynamic characteristics of the servo motor are improved, as the harmonics in the servo motion are reduced.

Optimal Mechanism Design for Path Generation and Motions With Reduced Harmonic Content

2004 ◽  
Vol 126 (1) ◽  
pp. 191-196 ◽  
Author(s):  
Zhongfan Yuan ◽  
M. J. Gilmartin ◽  
S. S. Douglas
Keyword(s):  
Optimal Design ◽  
Mechanism Design ◽  
Fuzzy Theory ◽  
Path Generation ◽  
Frequency Bandwidth ◽  
Servo Motor ◽  
Output Link ◽  
Optimal Mechanism ◽  
Harmonic Content ◽  
Hybrid Mechanism

The optimal design of linkage mechanisms for path generation and motions with reduced harmonic content is investigated in this paper. The designs are carried out using a two-objective optimizer based on fuzzy theory. The four-bar mechanism is first optimally designed to follow a specified coupler path with the harmonic content of the output link motion being simultaneously minimized to reduce its oscillating frequency bandwidth. For more complicated paths, a five-bar hybrid mechanism driven by a constant speed motor and a servo motor is also optimally designed. The harmonics in the servo motion are also reduced in the design to improve the dynamic characteristics for the servo motor.

Dynamic and Positioning Performances of Linear Electromechanical Actuator

2015 ◽  
Vol 809-810 ◽  
pp. 682-687
Author(s):  
Vasile Nasui ◽  
Mihai Banica ◽  
Dinu Darabă
Keyword(s):  
Dynamic Characteristics ◽  
Practical Importance ◽  
Correct Identification ◽  
Positioning System ◽  
Positioning Error ◽  
Servo Motor ◽  
Positioning Accuracy ◽  
Electromechanical Actuator ◽  
Initial Errors ◽  
Selection For

This paper presents the dynamic characteristics and the proposed positioning performance of the system to them investigated experimentally. In this research, we developed the positioning system and we evaluated positioning accuracy. The developed system uses a servo motor for motion actuation. In this paper, we focused on studying the dependency of the positioning error – elementary errors – the position of the conducting element for the mechanism of the transformation of the rotation translation movement, representatively the mechanism screw – screwdriver and on emphasizing the practical consequences in the field of design, regulation and exploitation of the correct identification of all the initial errors in the structure of the mechanism, their character and the selection for an ultimate calculus of these which are of a real practical importance.

Analysis of Drive Shaft Speed Variations in a Scotch Yoke Mechanism

1982 ◽  
Vol 104 (1) ◽  
pp. 239-246 ◽  
Author(s):  
J. L. Wiederrich
Keyword(s):  
Practical Importance ◽  
Drive Shaft ◽  
Constant Speed ◽  
Shaft Speed ◽  
Flexible Coupling ◽  
Harmonic Content ◽  
Common Drive ◽  
Scotch Yoke Mechanism

Two analyses are presented for determining the drive shaft speed variations in a scotch yoke mechanism. The first analysis determines the speed variations when the mechanism is rigidly connected to a motor having a quadratic speed versus torque characteristic. The second analysis determines the speed variations when the mechanism is connected to a constant speed source through a flexible coupling. Together these models represent the two most common drive configurations. The results are of practical importance since they can be used in the preliminary calculations necessary in either the design of a main drive or the diagnosis of a drive problem in an existing machine. The methods are also of theoretical importance since they may be extended to the analysis of mechanisms having a greater harmonic content than the simple scotch yoke mechanism.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

Tool path optimal design for slow tool servo turning of complex optical surface

2016 ◽  
Vol 231 (5) ◽  
pp. 825-837 ◽  
Author(s):  
Xu Chen ◽  
Min Kang ◽  
Xingsheng Wang ◽  
Muhammad Hassan ◽  
Jun Yang
Keyword(s):  
Optimal Design ◽  
Tool Path ◽  
Tool Path Generation ◽  
Interpolation Error ◽  
Machining Accuracy ◽  
Calculation Error ◽  
Path Generation ◽  
Optical Surface ◽  
Toric Surface ◽  
Slow Tool Servo

In order to increase the machining accuracy of slow tool servo turning of complex optical surface, the optimal design for tool path was studied. A comprehensive tool path generation strategy was proposed to optimize the tool path for machining complex surfaces. A new algorithm was designed for tool nose radius compensation which had less calculation error. Hermite segment interpolation was analyzed based on integrated multi-axes controller, and a new interpolation method referred to as triangle rotary method was put forward and was compared with the area method and three-point method. The machining simulation indicated that the triangle rotary method was significant in error reduction. The interpolation error of toric surface was reduced to 0.0015 µm from 0.06 µm and sinusoidal array surface’s interpolation error decreases to 0.37 µm from 1.5 µm. Finally, a toric surface was machined using optimum tool path generation method to evaluate the proposed tool path generation method.

scholarly journals PD Plus Dynamic Pressure Feedback Control for a Direct Drive Stewart Manipulator

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1125 ◽  
Author(s):  
Chenyang Zhang
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Dynamic Characteristics ◽  
Control Strategy ◽  
Dynamic Pressure ◽  
Control Input ◽  
Servo Motor ◽  
Direct Drive ◽  
Pressure Feedback ◽  
Current Coupling

In order to ensure good dynamic characteristics, servo valve is usually adopted as the drive part of Stewart manipulator which causes huge power consumption, while direct drive electro-hydraulic servo system has the advantages of energy saving, simple structure, convenient installation, and low failure rate. But its dynamic characteristics are so poor that it can only be applied to occasions where quick response is not needed. On the consideration above, following works are done in this paper. Since current coupling exists in the control system based on the speed of the servo motor as the control input, the control system of the direct drive Stewart manipulator is established based on the current of the servo motor as the control input in which the current coupling can be solved. In order to improve the dynamic characteristics of the direct drive Stewart manipulator, a Proportion Differentiation (PD) plus dynamic pressure feedback control strategy is also put forward in this paper, which is verified by using a simulated hydraulically driven Stewart manipulator. Simulation results show that both dynamic coupling and current coupling are solved and the control strategy proposed in this paper can significantly increase the bandwidths of all degrees of freedom.

Vibration Characteristics Analysis of an Aero-Engine Turbine Blade

2012 ◽  
Vol 487 ◽  
pp. 894-897
Author(s):  
Wei Qiang Zhao ◽  
Yong Xian Liu ◽  
Mo Wu Lu ◽  
Qing Jun Guo
Keyword(s):  
Optimal Design ◽  
Turbine Blade ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Vibration Characteristic ◽  
Analysis Method ◽  
Aero Engine ◽  
Characteristics Analysis

This paper introduces the FEA method for a certain type of aero-engine turbine blade and makes a vibration characteristics analysis to this aero-engine turbine blade based on this method. The vibration characteristic of this aero-engine turbine blade is studied and the natural modal of the turbine blade is calculated based on UG software. The first six natural frequencies and mode shapes are given. According to the analysis results the dynamic characteristics of the blade are discussed. The analysis method and results in this paper can be used for further study on optimal design and vibration safety verification for the blade.

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