scholarly journals Investigation on the Modeling and Dynamic Characteristics of a Novel Hydraulic Proportional Valve Driven by a Voice Coil Motor

2021 ◽  
Vol 67 (5) ◽  
pp. 223-234
Author(s):  
Mingxing Han ◽  
Yinshui Liu ◽  
Yitao Liao ◽  
Shucai Wang
Keyword(s):  
Structural Parameters ◽  
Voice Coil Motor ◽  
Fast Response ◽  
Step Response ◽  
Test Results ◽  
Control Performance ◽  
Proportional Valve ◽  
Performance Simulation ◽  
Non Linear ◽  
Water Hydraulic

As the key control component of the water hydraulic systems, the water hydraulic proportional valve has a significant influence on the control performance of the systems. Due to the poor viscosity and lubricity of water, the valve spool resistance is large and non-linear. In this study, a novel fast-response water hydraulic proportional valve is presented. The actuator of the valve adopts a voice coil motor (VCM), which has the advantages of fast response, high control precision and small volume. In order to realize the fast control of the valve, a lever amplifier is designed to obtain enough actuation force. A detailed and precise non-linear mathematical model of the valve considering both the valve’s structural parameters and VCM electromagnetic characteristics is developed. A comprehensive performance simulation analysis has been carried out, mainly divided into an electromagnetic simulation, an analysis of the characteristics of the lever magnifier, and a dynamic performance simulation of the valve. The simulation results show that the adjusting time is about 28ms, and the maximum overshoot is about 5 %. The step response rise time is about 15 ms. The test rig of the valve and VCM have been built. The test results of the prototype show that the optimal stroke range of VCM is 4 mm to 15 mm. The maximum overshoot of the valve is around 10 %; the adjusting time is about 30 ms in the opening process and 35 ms in the closing process. The test results prove that the valve has good static and dynamic control performance.

scholarly journals Modeling and Dynamic Characteristics of a Novel High-Pressure and Large-Flow Water Hydraulic Proportional Valve

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Heng Zhang ◽  
Yaoyao Liao ◽  
Ze Tao ◽  
Zisheng Lian ◽  
Ruihao Zhao
Keyword(s):  
High Pressure ◽  
Structural Parameters ◽  
Nonlinear Flow ◽  
Step Response ◽  
Main Stage ◽  
The Novel ◽  
Mining Equipment ◽  
Closing Time ◽  
Proportional Valve ◽  
Large Flow

In the field of fully mechanized coal mining equipment, the hydraulic valve used in the hydraulic support is an on/off directional valve. There are many problems caused by the valve such as large pressure shock and discontinuous flow control. Therefore, a novel two-position three-way hydraulic proportional valve suitable for high-pressure and large-flow conditions is proposed to overcome the above problems. The novel valve utilizes a two-stage structure and the displacement follow-up principle is adopted between the pilot stage and the main stage to meet proportional control. In this paper, a simulation model of the novel proportional valve was established after a simplified analysis of the structural principle. Its reliability and the feasibility of the design were verified by the test results under different working conditions. Then, the step response characteristics of the proportional valve under different strokes were predicted and analyzed. Nonlinear characteristics were presented, and the closing time was shorter than the opening time because of the influence of nonlinear flow force. Under different ramp signals, the displacement of the main inlet spool was always approximately equal to the displacement of the pilot stage. Then, the motion relationship between the pilot stage and the main stage was studied, and the influence of the structural parameters on the stability was analyzed.

Stabilization and equilibrium control of a new pneumatic cart-seesaw system

Robotica ◽  
2008 ◽  
Vol 26 (2) ◽  
pp. 219-227 ◽  
Author(s):  
J. Lin ◽  
J. H. Zhan ◽  
Julian Chang
Keyword(s):  
State Feedback ◽  
Initial Position ◽  
Degree Of Freedom ◽  
Test Results ◽  
Control Performance ◽  
Proportional Valve ◽  
Pneumatic Control ◽  
Supervisory Controller ◽  
Equilibrium Control ◽  
And Control

SUMMARYThis investigation describes the mechanical configuration and control environment for a novel cart-seesaw system. This mechanism is called a super articulated mechanical system (SAMS). The system comprises a cart that slides on the pneumatic rodless cylinder. The rodless cylinder is double-acting with the carrier bracket, on which a cart is a pinion mechanism for the tracks. The cart-seesaw system brings the cart from any initial position to a desired position on the seesaw by applying an appropriate force to the cart and thus adjusting the angle of the seesaw. The position of a cart denotes the first degree of freedom, which is activated by a pneumatic proportional valve, and the angle of the seesaw indicates the second degree of freedom that is not actuated. Consequently, the proposed new pneumatic cart-seesaw system is straightforward to construct and direct to operate in different scenarios of performance. A state feedback controller is applied for stabilization of the equilibrium point of the system. Moreover, this study adds a supervisory controller that takes control action in extreme situations. Test results reveal excellent properties in control performance. The proposed product can be extensively applied in SAMS and pneumatic control for robotics control laboratory.

PI Control of Proportional Valve-Cylinder Water Hydraulic System

2014 ◽  
Vol 548-549 ◽  
pp. 977-984
Author(s):  
Xin Ba ◽  
Xiao Hui Luo ◽  
Xu Feng Zhao ◽  
Yu Quan Zhu
Keyword(s):  
Hydraulic System ◽  
Tap Water ◽  
Dead Zone ◽  
Response Speed ◽  
Hydraulic Cylinder ◽  
Fast Response ◽  
Pi Control ◽  
Proportional Valve ◽  
Working Medium ◽  
Water Hydraulic

Water hydraulic components have been developed rapidly in recent years. However many problems such as low lubricity and leakage limited the performance of them, especially water proportional valves. A proportional valve- hydraulic cylinder system with tap water as working medium is chosen as object to investigate the performance of water hydraulic system. With regarding to the weaknesses of the selected 4/3 proportional valve including lag, dead zone and nonlinearity, an integral separation PI arithmetic based close-loop controller is developed. Experiments results verified the electro-hydraulic proportional system of fast response speed and high accuracy.

FROUDE’S LAW OF SIMILITUDE – CONTEMPORARY AND FUTURE SEAKEEPING TESTING

2021 ◽  
Vol 153 (A2) ◽  
Author(s):  
R P Dallinga ◽  
R H M Huijsmans
Keyword(s):  
Model Test ◽  
Scale Effects ◽  
Higher Order ◽  
Air Pressure ◽  
Test Results ◽  
Viscous Effects ◽  
Two Phase ◽  
Scale Models ◽  
Non Linear

Historically “scale effects” in the interpretation of tests with scale models in waves using Froude’s Law of Similitude are mostly associated with viscous effects. Nowadays, with a much more complete modelling of reality and a focus on higher order non-linear phenomena, scaling of model test results implies a wider range of assumptions than the validity of Froude’s Law. Our contribution to the conference is a visionary review of contemporary and future problems in the interpretation of these tests. In this context we will discuss the developments in test techniques, including the development of a new Two-Phase Laboratory facilitating seakeeping and sloshing tests at reduced air pressure.

Non-Linear Analysis and Modeling of the Structure with Bolted Joints

2015 ◽  
Vol 656-657 ◽  
pp. 694-699
Author(s):  
Xin Liao ◽  
Jian Run Zhang ◽  
Dong Lu
Keyword(s):  
Dynamic Stiffness ◽  
Element Model ◽  
Outer Radius ◽  
Bolted Joints ◽  
Structure Model ◽  
Test Results ◽  
Bolted Joint ◽  
Joint Structure ◽  
Non Linear ◽  
Simulation Results

In this study, a non-linear finite element model for a simplified single-bolted joint structure model is built. Static analysis on the structure under different shear force and pretension effect is done, and the non-linear contact behavior is analyzed. Through comparing datum, it is found that interface area of each bolted joint region can be described an annular region around bolt hole, whose outer radius has increased by 85% compared with radius of bolt hole. Also, the frequency responses of the multi-bolted joint structure under sinusoidal excitation are investigated. Simulation results show that the resonance regions basically remain unchanged in different pretension effect and the largest amplitude will increase with the increasing preloads. Finally, the vibration experiments are conducted. Interface nonlinear affect dynamic stiffness considerably. The test results illustrate that dynamic behaviors of bolted joint agree with the simulation results and the proposed non-linear contact model was reasonable.

TESTING FOR LINEAR AND NON-LINEAR GRANGER NON-CAUSALITY HYPOTHESIS BETWEEN STOCK AND BOND: THE CASES OF MALAYSIA AND SINGAPORE

2014 ◽  
Vol 59 (05) ◽  
pp. 1450045 ◽  
Author(s):  
SHEUE LI ONG ◽  
CHONG MUN HO
Keyword(s):  
Linear Relationship ◽  
Taylor Expansion ◽  
Empirical Studies ◽  
Causal Relationships ◽  
Test Results ◽  
Causality Test ◽  
Dynamic Relationship ◽  
Non Linear ◽  
Causality Hypothesis ◽  
Actual Relationship

The untested assumption of linear relationship between stocks and bonds in previous empirical studies may lead to an invalid conclusion if the actual relationship is non-linear. The emphasis of this paper is on the effect of non-linearities on causal relationships between stocks and bonds in the cases of Malaysia and Singapore. Results from linearity tests indicate the existence of non-linearities in the dynamic relationship between stocks and bonds. Non-linear causality test results based on Taylor expansion suggest that non-linear causality flows from stocks to bonds and vice versa. The test further confirms that bonds with different maturity dates have different relationships with stocks.

scholarly journals Tunable Non-linear Refraction Properties and Ultrafast Excited State Dynamics of Dicyanomethylene Dihydrofuran Derivative

2020 ◽  
Vol 8 ◽  
Author(s):  
Linpo Yang ◽  
Zhongguo Li ◽  
Taihui Wei ◽  
Liming Zhou ◽  
Feng Li ◽  
...  
Keyword(s):  
Excited State ◽  
Transient Absorption ◽  
Refraction Index ◽  
Fast Response ◽  
Transient Absorption Spectroscopy ◽  
Relaxation Dynamics ◽  
Substantial Impact ◽  
Femtosecond Transient Absorption ◽  
Non Linear ◽  
Linear Optical

The third order non-linear optical response of a dicyanomethylene dihydrofuran compound (DCDHF-2V) was investigated using a Z-scan technique in picosecond and nanosecond time regimes. The results show that DCDHF-2V has excellent excited state non-linear refraction properties on both time regimes, and the non-linear refraction index is also solvent-dependent in the nanosecond regime. The excited state relaxation dynamics of DCDHF-2V were demystified via femtosecond transient absorption spectroscopy. The TA spectra reveal that the solvent viscosities have a substantial impact on the excited state relaxation of DCDHF-2V. The exotic photophysical phenomena in DCDHF-2V reported herein can shed new light on future development of small organic non-linear optical materials with large non-linear coefficients and fast response.

scholarly journals Finite-element analysis and structure optimization of X-O composite seal of cone bit

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091868
Author(s):  
Shuang Jing ◽  
Anle Mu ◽  
Yi Zhou ◽  
Ling Xie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Parameters ◽  
Structure Optimization ◽  
Seal Ring ◽  
Test Results ◽  
Element Analysis ◽  
Root Cause ◽  
Sealing Performance ◽  
Distribution Of Stress

The seal is the key part of the cone bit. To reduce the failure probability, a new seal was designed and studied. The sealing performance and structure optimization of the X-O composite seal was analyzed and compared by finite-element analysis. The stress and contact pressure were analyzed to establish the main structural parameters that affect sealing performance and the direction of the structural optimization. By optimizing these structural parameters, including the height, and the radial and axial arc radii, an optimized structure is obtained. The results show that (1) the X-O composite seal can meet the seal requirement, the excessive height of the X seal ring is the root cause of the uneven distribution of stress, pressure, and distortion. (2) A new seal structure is obtained, the distribution of pressure and stress is reasonable and even, and the values of stress and pressure are reduced to avoid distortion and reduce the wear. Finally, the field test results of the X-O composite seal of cone bit showed that the service life of the bit bearing increased by 16% on average and the drilling efficiency increased by 11% on average compared with the original cone bit with the O seal ring.

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