scholarly journals The Energy Compensation of the HRG Based on the Double-Frequency Parametric Excitation of the Discrete Electrode

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3549
Author(s):  
Wanliang Zhao ◽  
Hao Yang ◽  
Fucheng Liu ◽  
Yan Su ◽  
Lijun Song
Keyword(s):  
Parametric Excitation ◽  
Dynamical Equation ◽  
Dynamic Performance ◽  
Free Precession ◽  
Double Frequency ◽  
Energy Compensation ◽  
Hemispherical Resonator ◽  
The Stability ◽  
Resonator Vibration ◽  
Excitation Parameters

In this study, for energy compensation in the whole-angle control of Hemispherical Resonator Gyro (HRG), the dynamical equation of the resonator, which is excited by parametric excitation of the discrete electrode, is established, the stability conditions are analyzed, and the method of the double-frequency parametric excitation by the discrete electrode is derived. To obtain the optimal parametric excitation of the resonator, the total energy stability of the resonator is simulated for the evolution of the resonator vibration with different excitation parameters and the free precession of the standing wave by the parametric excitation. In addition, the whole-angle control of the HRG is designed, and the energy compensation of parametric excitation is proven by the experiments. The results of the experiments show that the energy compensation of the HRG in the whole-angle control can be realized using discrete electrodes with double-frequency parametric excitation, which significantly improves the dynamic performance of the whole-angle control compared to the force-to-rebalance.

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

The Correlation between Time and Frequency Dynamic Performance of Control System

2014 ◽  
Vol 628 ◽  
pp. 186-189
Author(s):  
Meng Xiong Zeng ◽  
Jin Feng Zhao ◽  
Wen Ouyang
Keyword(s):  
Control System ◽  
Performance Index ◽  
Dynamic Performance ◽  
Frequency Domain Analysis ◽  
Practical Significance ◽  
Order System ◽  
Time Frequency ◽  
Performance Indexes ◽  
Quantitative Performance ◽  
The Stability

The control system performance requirement was divided into three parts. They were the stability, rapidity and accuracy. The time-frequency domain analysis in the requirements of three performance were measured through quantitative performance index. The mutual restriction of time-frequency performance and system characteristic parameters of normal second order was discussed. The correlation of system time-frequency performance index was established. The relationship between time-frequency performance indexes in standard two order system was extended to higher order system. The mutually constraining and time-frequency correlation between each performance index was obtained by analysis and calculation. The work had been done above had practical significance to reflect the system dynamic performance in different analytical domains.

Coordinated Control for Novel Full Hybrid Vehicles

2013 ◽  
Vol 860-863 ◽  
pp. 1073-1077 ◽  
Author(s):  
Zhi Guo Kong ◽  
Hong Wei Zhang ◽  
Zi Ning Tang
Keyword(s):  
Control Method ◽  
Dynamic Performance ◽  
Coordinated Control ◽  
Rate Of Change ◽  
Adjustment Process ◽  
Accelerator Pedal ◽  
Dynamic Constraints ◽  
Electric Bus ◽  
The Stability ◽  
Working Point

In order to improve the performance of a new type of full hybrid electric bus, this paper puts forward a set of coordinated control method to adjust the operation of the engine and two motors. In the engine start-stop logic control, comprehensive consideration of SOC, the speed of the bus and the accelerator pedal stroke are performed, while hysteresis control is introduced to improve the stability of the control; In the engine working point adjusting control, not only the engine speed command rate of change was optimized, but also the output torque rate was optimized to match the air injection and exhaust, etc. Further, the method based on dynamic constraints was used to optimize the working point adjustment process. At present, there are hundreds of busses operates in route. Results verify the feasibility and effectiveness of the control method. The vehicle has good fuel economy, and the dynamic performance and driving comfort are also greatly improved.

Effect of Intermolecular Forces on the Static and Dynamic Performance of Air Bearing Sliders: Part II—Dependence of the Stability on Hamaker Constant, Suspension Preload and Pitch Angle

2005 ◽  
Vol 128 (1) ◽  
pp. 203-208 ◽  
Author(s):  
Vineet Gupta ◽  
David B. Bogy
Keyword(s):  
Pitch Angle ◽  
Dynamic Performance ◽  
Hard Disk Drives ◽  
Intermolecular Forces ◽  
Flying Height ◽  
Total Force ◽  
Air Bearing ◽  
Force Increase ◽  
The Stability ◽  
Fly Height

Intermolecular and surface forces contribute significantly to the total forces acting on air bearing sliders for flying heights below 5 nm. Their contributions to the total force increase sharply with the reduction in flying height, and hence their existence can no longer be ignored in air bearing simulation for hard disk drives. Various experimentally observed dynamic instabilities can be explained by the inclusion of these forces in the model for low flying sliders. In this paper parametric studies are presented using a 3-DOF model to better understand the effect of the Hamaker constants, suspension pre load and pitch angle on the dynamic stability/instability of the sliders. A stiffness matrix is used to characterize the stability in the vertical, pitch, and roll directions. The fly height diagrams are used to examine the multiple equilibriums that exist for low flying heights. It has been found that the system instability increases as the magnitude of the van der Waals force increases. It has also been found that higher suspension pre load and higher pitch angles tend to stabilize the system.

scholarly journals Bright-Dark and Multi Solitons Solutions of (3 + 1)-Dimensional Cubic-Quintic Complex Ginzburg–Landau Dynamical Equation with Applications and Stability

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 202 ◽  
Author(s):  
Chen Yue ◽  
Dianchen Lu ◽  
Muhammad Arshad ◽  
Naila Nasreen ◽  
Xiaoyong Qian
Keyword(s):  
Dynamical Equation ◽  
Landau Equation ◽  
Applied Physics ◽  
Ginzburg Landau ◽  
Open Set ◽  
Trigonometric Function Solutions ◽  
Kink Waves ◽  
Mathematical Techniques ◽  
The Stability ◽  
Complex Phenomena

In this paper, bright-dark, multi solitons, and other solutions of a (3 + 1)-dimensional cubic-quintic complex Ginzburg–Landau (CQCGL) dynamical equation are constructed via employing three proposed mathematical techniques. The propagation of ultrashort optical solitons in optical fiber is modeled by this equation. The complex Ginzburg–Landau equation with broken phase symmetry has strict positive space–time entropy for an open set of parameter values. The exact wave results in the forms of dark-bright solitons, breather-type solitons, multi solitons interaction, kink and anti-kink waves, solitary waves, periodic and trigonometric function solutions are achieved. These exact solutions have key applications in engineering and applied physics. The wave solutions that are constructed from existing techniques and novel structures of solitons can be obtained by giving the special values to parameters involved in these methods. The stability of this model is examined by employing the modulation instability analysis which confirms that the model is stable. The movements of some results are depicted graphically, which are constructive to researchers for understanding the complex phenomena of this model.

Novel robust controller design for load sway reduction in double-pendulum overhead cranes

2018 ◽  
Vol 233 (12) ◽  
pp. 4359-4371 ◽  
Author(s):  
Huimin Ouyang ◽  
Xin Deng ◽  
Huan Xi ◽  
Jinxin Hu ◽  
Guangming Zhang ◽  
...  
Keyword(s):  
Controller Design ◽  
Dynamic Performance ◽  
Optimization Method ◽  
Linear Matrix ◽  
Double Pendulum ◽  
Control Performance ◽  
Mass Property ◽  
Length Changes ◽  
The Stability ◽  
Dynamic Performance Analysis

It is seen that when the hook mass is larger than the load mass or the load has distributed mass property, the load sway of the crane system presents as double-pendulum effect. In this situation, crane system has two different natural frequencies so that the sway characteristic becomes more complex and greatly increases the difficulty of the dynamic performance analysis and controller design. Moreover, the rope length changes significantly affect the stability and control performance of the crane system. In order to solve the aforementioned problems, the linear dynamics of a two-dimensional overhead crane with double-pendulum effect is derived based on a disturbance observer, and is decoupled for controller design by modal analysis. Next, a state feedback controller is presented to achieve robust control performance for a given range of rope length changes. The controller gains are obtained via linear matrix inequality optimization method. Finally, numerical simulations and experimental results validate that the proposed method has superior control performance.

Dynamic Performance and Stability Research of VMI-APIOBPCS in Apparel Industry Based on Control Theory

2018 ◽  
Vol 14 (2) ◽  
pp. 56-76 ◽  
Author(s):  
Xueli Zhan ◽  
Qin Zhang ◽  
Wenfeng Xie
Keyword(s):  
Supply Chain ◽  
Control Theory ◽  
System Integration ◽  
Production Control ◽  
Dynamic Performance ◽  
Apparel Industry ◽  
Supply Chain System ◽  
Hurwitz Stability ◽  
New Ideas ◽  
The Stability

In this article, the authors mainly investigate the dynamic performance of VMI-APIOBPCS (Vendor Manage Inventory-Automatic Pipeline Inventory and Order Based Production Control System) in the apparel industry. With the increasing importance of supply chain system integration, VMI-APIOBPCS can integrate various kinds of elements in the real operation, which is proved to be very effective in solving complex problems. Apparel supply chains have relatively more complicated dynamic behaviors because of the factors like volatile demand, the strong seasonality of sales and the large number of items with short life cycle or lacking historical data. In order to clear these behaviors, and come up with new ideas to solve present difficulties, the authors apply classic control theory to build up the model of VMI-APIOBPCS in apparel supply chain. They then analyze the dynamic performance of apparel supply chain and use Routh-Hurwitz Stability Criterion to analyze the stability on the expectation that the outcomes of our research can be useful in the practical occasions.

scholarly journals Structural model and dynamic analysis of six-axis Cartesian coordinate robot for sheet metal bending

2019 ◽  
Vol 16 (4) ◽  
pp. 172988141986156
Author(s):  
Fengyu Xu ◽  
Quansheng Jiang ◽  
Lina Rong ◽  
Pengfei Zhou ◽  
Jinlong Hu
Keyword(s):  
Dynamic Analysis ◽  
Sheet Metal ◽  
Laboratory Testing ◽  
Structural Model ◽  
Dynamic Performance ◽  
Work Conditions ◽  
Structure Model ◽  
Sheet Metal Bending ◽  
Cartesian Coordinate ◽  
The Stability

Bending is an important procedure for processing sheet metals, while it is a key link in the realization of automatic processing of sheet metal. To improve the efficiency and accuracy of bending processing, this article proposed a structure model and a prototype of a six-axis Cartesian coordinate robot for sheet metal bending to replace workers completing automatic bending processes. Based on the analysis of overall structure schemes of the robot, kinematic simulation is conducted by using the automatic dynamic analysis of mechanical system (ADAMS). Furthermore, the dynamic performance of the structural model of the robot for sheet metal bending is analysed and design optimization is performed. A prototype of the robot based on the optimal structural model of six-axis Cartesian coordinate robot for sheet metal bending is made. Finally, under the work conditions, the efficiencies and accuracies of sheet metal bending by a worker and the robot are compared and tested. The structural model of six-axis Cartesian coordinate robot for sheet metal bending presented in this article is found to be applicable to sheet metal bending robot and improves the stability of sheet metal bending machine. The laboratory testing and experimental results verified the feasibility of the proposed robot.

Simultaneous Resonance and Anti-Resonance in Dynamical Systems Under Asynchronous Parametric Excitation

2020 ◽  
Vol 15 (9) ◽  
Author(s):  
Artem Karev ◽  
Peter Hagedorn
Keyword(s):  
Dynamical Systems ◽  
Parametric Excitation ◽  
Analytical Method ◽  
Normal Forms ◽  
High Sensitivity ◽  
Combination Resonance ◽  
Concurrent Study ◽  
The Stability ◽  
Analytical Expressions ◽  
Special Case

Abstract Since the discovery of parametric anti-resonance, parametric excitation has also become more prominent for its stabilizing properties. While resonance and anti-resonance are mostly studied individually, there are systems where both effects appear simultaneously at each combination resonance frequency. With a steep transition between them and a high sensitivity of their relative positions, there is a need for a concurrent study of resonance and anti-resonance. The semi-analytical method of normal forms is used to derive approximate analytical expressions describing the magnitude of the stability impact as well as the precise locations of stabilized and destabilized areas. The results reveal that the separate appearance of resonance and anti-resonance is only a special case occurring for synchronous parametric excitation. In particular, in circulatory systems the simultaneous appearance is expected to be much more common.

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