scholarly journals PFC-Based Control of Friction-Induced Instabilities in Drive Systems

Machines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 134
Author(s):  
Ievgen Golovin ◽  
Stefan Palis
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Angular Velocity ◽  
Observer Design ◽  
Zero Dynamics ◽  
Positive Real ◽  
Control Approach ◽  
Augmented System ◽  
Damping Control ◽  
Drive Systems

This paper is concerned with control-based damping of friction-induced self-excited oscillations that appear in electromechanical systems with an elastic shaft. This approach does not demand additional oscillations measurements or an observer design. The control system provides the angular velocity and damping control via the combination of a parallel feed-forward compensator (PFC) and adaptive λ-tracking feedback control. The PFC is designed to stabilize the zero dynamics of an augmented system and renders it almost strict positive real (ASPR). The proposed control approach is tested in simulations.

Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

2000 ◽  
Vol 122 (2) ◽  
pp. 262-268 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control. [S0742-4795(00)00702-X]

scholarly journals Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

1998 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control.

Effect of Inner and Outer Wheels Driving Force Control on Small Electric Vehicle

2020 ◽  
Vol 17 (4) ◽  
pp. 8246-8254
Author(s):  
K. Shibazaki ◽  
H. Nozaki
Keyword(s):  
Control System ◽  
Angular Velocity ◽  
Electric Vehicle ◽  
Force Constant ◽  
Force Control ◽  
Driving Force ◽  
Vehicle Control ◽  
Steering Angle ◽  
Force Control System ◽  
The Difference

In this study, in order to improve steering stability during turning, we devised an inner and outer wheel driving force control system that is based on the steering angle and steering angular velocity, and verified its effectiveness via running tests. In the driving force control system based on steering angle, the inner wheel driving force is weakened in proportion to the steering angle during a turn, and the difference in driving force is applied to the inner and outer wheels by strengthening the outer wheel driving force. In the driving force control (based on steering angular velocity), the value obtained by multiplying the driving force constant and the steering angular velocity,  that differentiates the driver steering input during turning output as the driving force of the inner and outer wheels. By controlling the driving force of the inner and outer wheels, it reduces the maximum steering angle by 40 deg and it became possible to improve the cornering marginal performance and improve the steering stability at the J-turn. In the pylon slalom it reduces the maximum steering angle by 45 deg and it became possible to improve the responsiveness of the vehicle. Control by steering angle is effective during steady turning, while control by steering angular velocity is effective during sharp turning. The inner and outer wheel driving force control are expected to further improve steering stability.

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