The Railway Wheelset and Suspension Unit as a Closed-Loop Guidance Control System: A Method for Performance Improvement

Using a simplified mathematical model, the conventional railway wheelset and suspension unit is shown to behave as a closed-loop guidance control system. The centre-line of the track corresponds to the input, and the lateral position of the centroid of the wheelset to the output. Analysis of the system shows that, while it may be made stable at up to high speeds, the performance in the stable region is unsatisfactory in certain respects. This is attributed to the large forces of interaction between the wheels and rails at the points of contact, arising, in the case of the conventional wheelset, from creepage. These forces may be reduced and controlled by interposing a coupling having viscous characteristics between the wheels, in place of the rigid axle. The new arrangement is shown to be much more flexible, and capable of fulfilling a wide range of performance requirements.

Download Full-text

Reduction Methods of Structure Models for Control System Purposes

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.248.119 ◽

2016 ◽

Vol 248 ◽

pp. 119-126 ◽

Cited By ~ 2

Author(s):

Andrzej Koszewnik ◽

Zdzisław Gosiewski

Keyword(s):

Control System ◽

High Frequency ◽

Closed Loop ◽

Flexible Structures ◽

Low Frequency ◽

Point Of View ◽

Closed Loop Systems ◽

System A ◽

Reduction Methods ◽

The Stability

To design vibration control system for flexible structures their mathematical model should be reduced. In the paper we consider the influence of the model reduction on the dynamics of the real closed-loop system. A simply cantilever beam is an object of consideration since we are able to formulate the exact analytical model of such structure. As a result of reduction the model with low frequency resonances is usually separated from the high frequency dynamics because high frequency part of the model is naturally strong damped. In order to estimate dynamical system for control purposes in the paper we applied a few orthogonal methods such as: modal, Rayleigh-Ritz and Schur decompositions. As it is shown all methods well calculate resonances frequencies but generate different anti-resonances frequencies. From control strategy in point of view of the flexible structures these anti-resonances have significantly influence on the stability and dynamics of the closed-loop systems.

Download Full-text

FLUENT/SIMULINK Collaborative Simulation for Missile Separation from Cavity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.1902 ◽

2012 ◽

Vol 591-593 ◽

pp. 1902-1906

Author(s):

Tong Han ◽

Shang Qin Tang ◽

Chang Qiang Huang ◽

Kang Sheng Dong

Keyword(s):

Control System ◽

Closed Loop ◽

Control Method ◽

Data File ◽

Control Model ◽

Collaborative Simulation ◽

Coupled Problem ◽

System A ◽

Share Data ◽

Simulation Results

In order to solve the dynamics and kinematics highly coupled problem which exists in missile separating from cavity and in order to acquire accurate trajectory parameters and import control system, a parallel collaborative simulation platform was established. The data interface between FLUENT and SIMULINK was developed by the way of share data file, which use the Journal file of FLUENT and S-function of SIMULINK. The missile’s rudder control model was established. The aerodynamics characters and trajectory characters during missile separating from cavity were simulated under uncontrolled and closed-loop controlled conditions. The simulation results verify the feasibility of parallel collaborative simulation and show that rudder control method can effectively improve the characteristics of missile separating from cavity.

Download Full-text

Design and Realization of Intelligent Phase-controlled System for Permanent Magnetic Actuator of AC Contactor

E3S Web of Conferences ◽

10.1051/e3sconf/202016506019 ◽

2020 ◽

Vol 165 ◽

pp. 06019

Author(s):

Chen Ya bin ◽

Zhang Zhen tao ◽

Li Qiang ◽

Zou Ping Guo

Keyword(s):

Control System ◽

Phase Angle ◽

Capacitor Bank ◽

Inrush Current ◽

Magnetic Actuator ◽

Phase Selection ◽

Intelligence System ◽

Permanent Magnetic Actuator ◽

Performance Requirements ◽

System A

When the AC contactor switches the capacitor bank, the phase angle of the power grid is random, so the electromagnetic transient process will generate large inrush current and overvoltage, causing large disturbance to the power system. A set of AC contactor with permanent magnetic actuator (PMA) and its intelligent phase selection control system are designed to solve this problem. Firstly, the PMA is designed. The dynamic characteristics of the actuator are simulated and analyzed in ANSOFT to meet the performance requirements of phase selection control. Then the principle of phase selection control and the strategy of switching capacitor bank are analyzed. Based on this, the software and hardware of intelligent phase selection control system are designed, including phase selection control module, IGBT driver module and coil discharge module. Finally, the experimental verification is carried out on the designed AC contactor. The test results show that the phase selection errors of the designed intelligence system are within 1°, and the contactor closing and opening time deviations are within 0.5ms, which means the system can effectively realize the closing and opening control at the specified phase angle.

Download Full-text

Closed Loop Fusion Technique for the Shaking Table Motion Control

Volume 1: Aerial Vehicles; Aerospace Control; Alternative Energy; Automotive Control Systems; Battery Systems; Beams and Flexible Structures; Biologically-Inspired Control and its Applications; Bio-Medical and Bio-Mechanical Systems; Biomedical Robots and Rehab; Bipeds and Locomotion; Control Design Methods for Adv. Powertrain Systems and Components; Control of Adv. Combustion Engines, Building Energy Systems, Mechanical Systems; Control, Monitoring, and Energy Harvesting of Vibratory Systems ◽

10.1115/dscc2013-4018 ◽

2013 ◽

Author(s):

Keisuke Shimono ◽

Yasutaka Tagawa

Keyword(s):

Control System ◽

Closed Loop ◽

Control Function ◽

Shaking Table ◽

Low Frequencies ◽

Acceleration Signal ◽

Displacement Sensors ◽

Wide Range ◽

Loop Fusion ◽

Table Motion

Shaking tables are frequently used for dynamical testing. To produce correct results, a shaking table must be able to move according to the desired acceleration signal in a wide range of frequencies. Accelerometers and displacement sensors are used for controlling input, and, in some cases, they have been used for preventing drift. However, at low frequencies, accelerometers do not always provide accurate values. We developed a shaking-table control system that uses a sensor-fusion control function. In this paper, we present the design scheme for our control system and the results of a simulation that validate it.

Download Full-text

Robust Control System Design for Small UAV Using H2-Optimization

Land Forces Academy Review ◽

10.2478/raft-2018-0018 ◽

2018 ◽

Vol 23 (2) ◽

pp. 151-159

Author(s):

Róbert Szabolcsi

Keyword(s):

Control System ◽

Control Systems ◽

Closed Loop ◽

Closed Loop Control ◽

Worst Case ◽

Loop Control ◽

Closed Loop Control System ◽

Wide Range ◽

Loop Control System ◽

Dynamic Performances

Abstract Unmanned aerial vehicles are famous for their wide range of applications. In D3 (Dirty-Dull-Dangerous) UAV applications flight conditions may vary on large scale. External disturbances like atmospheric turbulences and gusts may be subjected to UAV, and as a result, UAV flight mission might be conducted with high level of the degradation of the accuracy. Sensor noises are also present, and theirs negligence might lead to improper dynamic performances of the closed loop control systems. Uncertainties of the control systems being structured or unstructured may tend the closed loop control system to stability bounds. In worst case, uncertainties may destabilize closed loop control systems. The purpose of the author is to present a robust controller design method called H2-optimal design ensuring stability of the closed loop control systems with simultaneous dynamic performances predefined for the closed loop control system.

Download Full-text