Control of Stability and the Synchronous Vibration of a Flexible Rotor Supported on Oil-Film Bearings

1985 ◽  
Vol 107 (2) ◽  
pp. 139-144 ◽  
Author(s):  
M. N. Sahinkaya ◽  
C. R. Burrows
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Open Loop ◽  
Flexible Rotor ◽  
Oil Film ◽  
Oil Whirl ◽  
Speed Range ◽  
Adaptive Control Strategy ◽  
The Stability ◽  
The Relationship

The relationship between eigenvalue loci for the rotor-bearing systems and the onset of instability due to oil-whirl, is utilized to derive an algorithm to control the onset of instability. Implementation of the algorithm is discussed. It is shown how this can be combined with an open-loop adaptive control strategy to ensure the stability of a flexible rotor and also minimize the synchronous vibration throughout the operational speed range.

Towards a new design with generic modeling and adaptive control of a transformable quadrotor

2021 ◽  
pp. 1-31
Author(s):  
S.H. Derrouaoui ◽  
Y. Bouzid ◽  
M. Guiatni
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Experimental Tests ◽  
Generic Model ◽  
System Control ◽  
System A ◽  
Viable Solution ◽  
Generic Modeling ◽  
Adaptive Control Strategy ◽  
The Stability

Abstract Recently, transformable Unmanned Aerial Vehicles (UAVs) have become a subject of great interest in the field of flying systems, due to their maneuverability, agility and morphological capacities. They can be used for specific missions and in more congested spaces. Moreover, this novel class of UAVs is considered as a viable solution for providing flying robots with specific and versatile functionalities. In this paper, we propose (i) a new design of a transformable quadrotor with (ii) generic modeling and (iii) adaptive control strategy. The proposed UAV is able to change its flight configuration by rotating its four arms independently around a central body, thanks to its adaptive geometry. To simplify and lighten the prototype, a simple mechanism with a light mechanical structure is proposed. Since the Center of Gravity (CoG) of the UAV moves according to the desired morphology of the system, a variation of the inertia and the allocation matrix occurs instantly. These dynamics parameters play an important role in the system control and its stability, representing a key difference compared with the classic quadrotor. Thus, a new generic model is developed, taking into account all these variations together with aerodynamic effects. To validate this model and ensure the stability of the designed UAV, an adaptive backstepping control strategy based on the change in the flight configuration is applied. MATLAB simulations are provided to evaluate and illustrate the performance and efficiency of the proposed controller. Finally, some experimental tests are presented.

BIFURCATION TAILORING VIA NEWTON FLOW-AIDED ADAPTIVE CONTROL

2003 ◽  
Vol 13 (03) ◽  
pp. 677-684 ◽  
Author(s):  
XIAO FAN WANG ◽  
M. DI BERNARDO ◽  
D. P. STOTEN ◽  
M. H. LOWENBERG ◽  
G. CHARLES
Keyword(s):  
Adaptive Control ◽  
Bifurcation Diagram ◽  
Control Strategy ◽  
Open Loop ◽  
Control Synthesis ◽  
Control Law ◽  
Controlled System ◽  
Duffing System ◽  
Flow Algorithm ◽  
Adaptive Control Strategy

The aim of bifurcation tailoring is to design an appropriate control law such that the controlled system has a desired bifurcation diagram. After describing two open-loop bifurcation tailoring techniques, this paper proposes a new open-loop plus close-loop bifurcation tailoring method based on a combination of the Newton-flow algorithm and the minimal control synthesis (MCS) adaptive control strategy. This method is applied to the Duffing system as an illustrative example.

An Adaptive Weighting Control Strategy to Avoid Magnetic Bearing Contact

2009 ◽  
Author(s):  
Abdul-Hadi G. Abulrub ◽  
M. Necip Sahinkaya ◽  
Clifford R. Burrows
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Magnetic Bearing ◽  
Open Loop ◽  
Operating Conditions ◽  
Bearing Contact ◽  
Transient Disturbances ◽  
Objective Control ◽  
Adaptive Control Strategy ◽  
Relative Weighting

It was shown in an earlier paper that the authors’ recursive open loop adaptive control strategy can be used as the basis for an adaptive multi-objective control strategy to satisfy design criteria for rotor-bearing systems involving the relative weighting of forces transmitted to the foundation and rotor vibration. This paper describes a complementary-layer adaptive control strategy to limit vibration at critical locations along the rotor, where contact may occur, following changes in operating conditions, e.g. transient disturbances. Experiments are presented to explore the effectiveness of this approach.

Adaptive control strategy-based reference model for spacecraft motion trajectory

2014 ◽  
Vol 29 (5) ◽  
pp. 639-652 ◽  
Author(s):  
Zarina Samigulina ◽  
Olga Shiryayeva ◽  
Galina Samigulina ◽  
Hassen Fourati
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Reference Model ◽  
Motion Trajectory ◽  
Spacecraft Motion ◽  
Adaptive Control Strategy

Identification-Free Adaptive Separate Layer Water Injection Control Based on Expert Amendment

2010 ◽  
Vol 44-47 ◽  
pp. 1470-1475
Author(s):  
Feng Shan Wang ◽  
De Li Jia ◽  
Shu Jin Zhang ◽  
Chong Jiang Liu ◽  
De Kui Xu
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Water Injection ◽  
Strong Nonlinearity ◽  
Separate Layer ◽  
Injection Control ◽  
System Output ◽  
Adaptive Control Strategy ◽  
Injection Effect ◽  
Injection Technology

An identification-free adaptive control strategy based on expert amendment is proposed in this paper to solve the problem that it is difficult to establish mathematical model of water injection regulating process due to large time delay, strong nonlinearity and time variation in the flow control of separate layer water injection technology. In this control strategy, according to the past and current process information of water injection, the system output and trend can be estimated based on expert rules to amend the output of the identification-free adaptive control. The simulation result shows that this control strategy has perfect control performance and strong adaptability and it provides a feasible means for improving water injection effect.

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