Research on the displacement control method of asynchronous modular contactor

2017 ◽  
Author(s):  
Gong He ◽  
Zong Ming
Keyword(s):  
Control Method ◽  
Displacement Control ◽  
Displacement Control Method

Pseudo-Dynamic Testing Method Based on External Displacement Control

2012 ◽  
Vol 204-208 ◽  
pp. 2428-2432
Author(s):  
Da Peng Wang ◽  
Shi Zhu Tian
Keyword(s):  
Control Method ◽  
Dynamic Testing ◽  
Fast Response ◽  
Displacement Sensor ◽  
Internal Displacement ◽  
Displacement Control ◽  
Loop Control ◽  
Testing Technology ◽  
Hydraulic Servo ◽  
Displacement Control Method

In order to accelerate the velocity and improve the accuracy of the pseudo-dynamic testing，the external displacement control method is put forward based on the hardware control. The internal displacement sensor of the actuator is invalid on control and substituted by the LVDT displacement sensor connected with the specimen. The process of the feedback displacement and command error compensation is quickly implemented by the internal closed-loop control of the actuator. Compared with the iteratively approximate load control, this method not only makes the testing velocity fast, but also enables the error between command and feedback to be “zero”. The fast pseudo-dynamic testing about a cantilever beam is carried out by applying appropriate PID parameters of the actuator. The testing result shows that although this method has rather high requirements in the control system and electro-hydraulic servo load device, and the risk to some extent, the fast response of the actuator can be firmed by applying appropriate PID control parameters. This method provides a fast testing technology for velocity-dependent structures or specimens.

Dynamic Response of Pressure Compensated Variable Displacement Linkage Pump

2018 ◽  
Author(s):  
Nathaniel J. Fulbright ◽  
James D. Van de Ven
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Response Times ◽  
Control Line ◽  
Displacement Control ◽  
Mechanical Pressure ◽  
Control Valves ◽  
Variable Displacement ◽  
Simulation Results ◽  
Displacement Control Method

The Variable Displacement Linkage Pump (VDLP) uses an adjustable planar linkage to vary the displacement of the piston. Previous work focused on dynamic modeling of the pump at fixed displacements and therefore did not account for the displacement control method or the dynamics of changing displacement. One key application of the VDLP is in pressure compensated, high-pressure water hydraulics. This paper expands on previous modeling work to include the behavior of the hydro-mechanical pressure compensation valves and the displacement control linkage. The multi-domain dynamic model captures the fluid dynamics in the pumping chambers and poppet-style control valves; the dynamics of the control valves; and the kinematics and kinetics of the two degree-of-freedom nine-bar pump linkage. The dynamic model was exercised in a simulation of the pump responding to changing demands in the output flow rate. Simulation results showed that quick response times of 100 milliseconds to a step in the load were achieved. Overshoot of the displacement is damped using an orifice in the control line. A physical prototype of the VDLP was used to validate the simulation results.

Strong-Form Formulated Generalized Displacement Control Method for Large Deformation Analysis

2017 ◽  
Vol 09 (07) ◽  
pp. 1750101 ◽  
Author(s):  
Judy P. Yang ◽  
Jian-Yu Chen
Keyword(s):  
Numerical Integration ◽  
Large Deformation ◽  
Control Method ◽  
Strong Form ◽  
Collocation Methods ◽  
Deformation Analysis ◽  
Displacement Control ◽  
Large Deformation Analysis ◽  
Displacement Control Method ◽  
Generalized Displacement Control Method

The traditional analysis of geometric nonlinearity is mostly based on the weak-formulated Galerkin method such as the finite element method. The element nature has limited its application as a result of numerical integration in the governing equation and quality control of deformed mesh. In the middle of 1990s, the meshfree methods have been developed and become one leading research topic in computational mechanics. Especially, the strong form collocation methods require no additional efforts to process numerical integration and impose Dirichlet boundary condition, thereby making the collocation methods computationally efficient. In the incremental–iterative process, how to accurately reflect the change in the slope of the load–deflection curve of the structure and remain numerically stable are of major concerns. Thus, we propose a strong-form formulated generalized displacement control method to analyze geometric nonlinear problems, where the radial basis collocation method is adopted. The numerical examples demonstrate the ability of the proposed method for large deformation analysis.

Mixed Force and Displacement Control Strategy in Pseudo-Dynamic Tests for Structures with Large Stiffness

2013 ◽  
Vol 639-640 ◽  
pp. 1133-1136
Author(s):  
Xiao Jing Tan ◽  
Bin Wu
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Dynamic Testing ◽  
Displacement Transducer ◽  
Displacement Control ◽  
Mixed Control ◽  
Linear Variable Displacement Transducer ◽  
Experimental Validations ◽  
Displacement Control Method ◽  
Stability And Accuracy

Pseudo-dynamic testing using force- mixed control strategy is presented for structures with large stiffness. In this proposed method, the displacement response of the specimen measured by a linear variable displacement transducer with higher resolution than that in the actuator is fed back. A proportional-integral controller is adopted in the outer displacement control loop, and a coefficient CF is employed to convert the displacement to force command. Numerical and experimental validations show that this method exhibits excellent performance in terms of stability and accuracy if proper controller parameters are adopted and is superior to the conventional displacement control method for large-stiffness structures.

On the effect of constraint parameters on the generalized displacement control method

2014 ◽  
Vol 56 ◽  
pp. 123-129 ◽  
Author(s):  
Sofie E. Leon ◽  
Eduardo N. Lages ◽  
Catarina N. de Araújo ◽  
Glaucio H. Paulino
Keyword(s):  
Control Method ◽  
Displacement Control ◽  
Displacement Control Method ◽  
Generalized Displacement Control Method
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