Determination of Uncontrolled Sampling Frequency of the Electro-hydraulic Digital Control System with Clearance Nonlinear
Author(s): WEI Lie-jiang, WEI Xiao-ling, MA Bin, HAN Xiao, ZHANG Jing
Pages: 52-55
Year: 2015 Issue: 12
Journal: Hydraulics Pneumatics & Seals
Keyword: sampling frequency; clearance; rising time; setting time; overshoot;
Abstract: Based on an electro-hydraulic sampled-data control system with transmission chain clearance between the load and the piston rod, the factors that the mutation process of force when piston rod movement across the gap in the system when the mutation process of force, the bigger moment of inertia of the load and the bigger friction in the fulcrum are considered, and the model of the electro-hydraulic sam-pled-data control system with clearance nonlinear and zero order retainer is established. Using Matlab software, the response characteristics of the system under different sampling period are analyzed when the clearance is a certain value. The simulation results of a specific exam-ple show that, when the clearance is a certain value, a sampling frequency region that makes the system uncontrolled is existed;when the sampling frequency of the system goes into this region, the system overshoot volume increase, shock and impact intensify, and adjust time is longer, and even appear limit cycle oscillation and out of control, so the choice of sample frequency must avoid entering uncontrolled zone of the system.
Pages: 52-55
Year: 2015 Issue: 12
Journal: Hydraulics Pneumatics & Seals
Keyword: sampling frequency; clearance; rising time; setting time; overshoot;
Abstract: Based on an electro-hydraulic sampled-data control system with transmission chain clearance between the load and the piston rod, the factors that the mutation process of force when piston rod movement across the gap in the system when the mutation process of force, the bigger moment of inertia of the load and the bigger friction in the fulcrum are considered, and the model of the electro-hydraulic sam-pled-data control system with clearance nonlinear and zero order retainer is established. Using Matlab software, the response characteristics of the system under different sampling period are analyzed when the clearance is a certain value. The simulation results of a specific exam-ple show that, when the clearance is a certain value, a sampling frequency region that makes the system uncontrolled is existed;when the sampling frequency of the system goes into this region, the system overshoot volume increase, shock and impact intensify, and adjust time is longer, and even appear limit cycle oscillation and out of control, so the choice of sample frequency must avoid entering uncontrolled zone of the system.
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