COMPARATIVE ANALYSIS OF DIFFERENT ROTARY CONTROL SYSTEMS

2020 ◽  
Vol 6 ◽  
pp. 86-93
Author(s):  
R.K. ZARETSKIY
Keyword(s):  
Comparative Analysis ◽  
Control Systems ◽  
Friction Torque ◽  
Rotor System ◽  
Control Methods ◽  
Fluid Friction ◽  
Q Learning ◽  
Stiffness Coefficients ◽  
Relative Eccentricity ◽  
Bearing Stiffness

This article provides a comparative analysis of various control systems for a rotor system on fluid friction bearings. The control was carried out on the basis of the criterion of the minimum friction moment, the controlled parameter was the bearing stiffness coefficients. The following control methods were compared in terms of friction torque and rotor eccentricity: STATIC, PID, DQN, DDPG, Q-Learning and SARSA. The control systems were guided by the following observed parameters: the values of coordinates and velocities along the x, y axes, as well as the frictional moment and relative eccentricity.

Predictive, Deadbeat, and Combined Controls

2018 ◽  
Author(s):  
Sadegh Vaez-Zadeh
Keyword(s):  
Control Systems ◽  
Predictive Control ◽  
Direct Torque Control ◽  
Fast Response ◽  
Torque Control ◽  
Control Methods ◽  
Electric Motors ◽  
Operating Cycle ◽  
Combined Control ◽  
The One

In this chapter, three control methods recently developed for or applied to electric motors in general and to permanent magnet synchronous (PMS) motors, in particular, are presented. The methods include model predictive control (MPC), deadbeat control (DBC), and combined vector and direct torque control (CC). The fundamental principles of the methods are explained, the machine models appropriate to the methods are derived, and the control systems are explained. The PMS motor performances under the control systems are also investigated. It is elaborated that MPC is capable of controlling the motor under an optimal performance according to a defined objective function. DBC, on the other hand, provides a very fast response in a single operating cycle. Finally, combined control produces motor dynamics faster than one under VC, with a smoother performance than the one under DTC.

Take-off control and characteristics of FanWing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lin Meng ◽  
Yang Gao ◽  
Yangyang Liu ◽  
Shengfang Lu
Keyword(s):  
Control System ◽  
Control Systems ◽  
Design Methodology ◽  
Control System Design ◽  
Control Methods ◽  
Force Analysis ◽  
Close Attention ◽  
Content Type ◽  
Vehicle Load ◽  
Practical Implications

Purpose As a short take-off and landing aircraft, FanWing has the capability of being driven under power a short distance from a parking space to the take-off area. The purpose of this paper is to design the take-off control system of FanWing and study the factors that influence the short take-off performance under control. Design/methodology/approach The force analysis of FanWing is studied in the take-off phase. Two take-off control methods are researched, and several factors that influence the short take-off performance are studied under control. Findings The elevator and fan wing control systems are designed. Although the vehicle load increases under the fan wing control, the fan wing control is not a recommended practice in the take-off phase for its sensitivity to the pitch angle command. The additional pitch-down moment has a significant influence on the control system and the short take-off performance that the barycenter variation of FanWing should be considered carefully. Practical implications The presented efforts provide a reference for the location of the center of gravity in designing FanWing. The traditional elevator control is more recommended than the fan wing control in the take-off phase. Originality/value This paper offers a valuable reference on the control system design of FanWing. It also proves that there is an additional pith-down moment that needs to be paid close attention to. Four factors that influence the short take-off performance are compared under control.

Performance of Plain Journal Bearings Operating Under Vortex Flow Conditions

1974 ◽  
Vol 96 (1) ◽  
pp. 145-149 ◽  
Author(s):  
J. Freˆne ◽  
M. Godet
Keyword(s):  
Reynolds Number ◽  
Friction Torque ◽  
Point Of View ◽  
Taylor Vortex ◽  
Experimental Program ◽  
Frictional Torque ◽  
Taylor Vortices ◽  
Attitude Angle ◽  
Relative Eccentricity ◽  
High Reynolds

An experimental program conducted on an original device was undertaken to study the performance of plain bearings operating at sufficiently high Reynolds number to introduce Taylor vortices. Curves of relative eccentricity, attitude angle, and friction torque were obtained versus speed and load. Experimental results conducted for Reynolds number smaller than 1100 indicate that both laminar and Taylor vortex regimes are encountered. The occurrence of the vortices is identified by a break in the slope of the friction torque versus speed curves. The position of the break is in good agreement with the theoretical predictions of Di Prima and Ritchie. From the practical point of view, the data show that for constant viscosity the occurence of Taylor vortices does not alter the curves of eccentricity versus either speed or load but modifies the attitude angle and frictional torque. In turn, the increase in frictional torque, and subsequently of temperature may cause a decrease in viscosity and thus a drop in load carrying capacity for fluids such as oils whose variations of viscosity with temperature is large.

scholarly journals Comprehensive Control of Networked Control Systems with Multistep Delay

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Jie Jiang ◽  
Changlin Ma
Keyword(s):  
Time Delay ◽  
Control Systems ◽  
Networked Control Systems ◽  
Sampling Period ◽  
Networked Control ◽  
Control Methods ◽  
Delay Compensation ◽  
Linear Quadratic ◽  
Long Time ◽  
Time Delay Compensation

In networked control systems with multi-step delay, long time-delay causes vacant sampling and controller design difficulty. In order to solve the above problems, comprehensive control methods are proposed in this paper. Time-delay compensation control and linear-quadratic-Guassian (LQG) optimal control are adopted and the systems switch different controllers between two different states. LQG optimal controller is used with probability1-αin normal state, which is shown to render the systems mean square exponentially stable. Time-delay compensation controller is used with probabilityαin abnormal state to compensate vacant sampling and long time-delay. In addition, a buffer window is established at the actuator of the systems to store some history control inputs which are used to estimate the control state of present sampling period under the vacant sampling cases. The comprehensive control methods simplify control design which is easier to be implemented in engineering. The performance of the systems is also improved. Simulation results verify the validity of the proposed theory.

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