Turbocharger rotor vibration reduction methodology with an active control scheme

2021 ◽  
pp. 095745652110307
Author(s):  
Rajasekhara Reddy Mutra ◽  
J Srinivas ◽  
Jakeer Hussain Shaik ◽  
Maddela Chinna Obaiah ◽  
Gunji Balamurali ◽  
...  
Keyword(s):  
High Speed ◽  
Active Vibration Control ◽  
Vibration Reduction ◽  
Open Loop ◽  
Rotor System ◽  
Dynamic Responses ◽  
Experimental Result ◽  
Loop Control ◽  
Highly Nonlinear ◽  
Control Configuration

The turbocharger rotors are often supported on the dual film floating ring bearings that are meant for high-speed applications. The damping ability of these bearings is relatively high. However, due to highly nonlinear bearing forces, often system instability occurs. The present work focuses on the dynamic analysis and active vibration control studies of a practical turbocharger rotor system with the use electromagnetic actuator (EMA) system. Initially, the system is analyzed using the finite element approach. The inner and outer film forces are considered along with rotor imbalance forces. The dynamic responses at the critical operating speeds are obtained numerically. To minimize the vibration amplitudes, a tiny EMA system is installed at one of the nodes along the shaft. The effect of the EMA parameters such as the number of turns of winding coil around a pole ( N c) and pole-face area ( A a) on the response of the system is studied. Further, an open-loop control configuration is practically studied by using a vibration shaker at the bearing node under different operating speeds, and the percentage reduction in critical vibration amplitudes is recorded. The EMA system is effectively controlling the high-speed rotor system vibrations. The EMA parameters N c and A a are influencing the system vibration response. Further, an experimental result has given considerable vibration reduction with the present approach.

Numerical investigation of chatter suppression in milling using active fixtures in open-loop control

2016 ◽  
Vol 24 (9) ◽  
pp. 1757-1773 ◽  
Author(s):  
Lorenzo Sallese ◽  
Niccolò Grossi ◽  
Antonio Scippa ◽  
Gianni Campatelli
Keyword(s):  
Numerical Investigation ◽  
Removal Rate ◽  
Active Vibration Control ◽  
Open Loop ◽  
Influential Factors ◽  
Depth Of Cut ◽  
Control Logic ◽  
Loop Control ◽  
Testing Environment ◽  
Chatter Suppression

Among the chatter suppression techniques in milling, active fixtures seem to be the most industrially oriented, mainly because these devices could be directly retrofittable to a variety of machine tools. The actual performances strongly depend on fixture design and the control logic employed. The usual approach in the literature, derived from general active vibration control applications, is based on the employment of adaptive closed-loop controls aimed at mitigating the amplitude of chatter frequencies with targeted counteracting vibrations. Whilst this approach has proven its effectiveness, a general application would demand a wide actuation bandwidth that is practically impeded by inertial forces and actuator-related issues. This paper presents the study of the performance of alternative open-loop actuation strategies in suppressing chatter phenomena, aiming at limiting the required actuation bandwidth. A dedicated time-domain simulation model, integrating fixture dynamics and the features of piezoelectric actuators, is developed and experimentally validated in order to be used as a testing environment to assess the effectiveness of the proposed actuation strategies. An extensive numerical investigation is then carried out to highlight the most influential factors in assessing the capability of suppressing chatter vibrations. The results clearly demonstrated that the regenerative effect could be effectively disrupted by actuation frequencies close to half the tooth-pass frequency, as long as adequate displacement is provided by the actuators. This could sensibly increase the critical axial depth of cut and hence improve the achievable material removal rate, as discussed in the paper.

scholarly journals The Modelling, Simulation and FPGA-Based Implementation for Stepper Motor Wide Range Speed Closed-Loop Drive System Design

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Closed Loop ◽  
Open Loop ◽  
Drive System ◽  
Stepper Motor ◽  
Motor Drive ◽  
Digital Controllers ◽  
Loop Control ◽  
Wide Range

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.

Effects of Piezoceramic Actuator in Quasistatic Use

2014 ◽  
Author(s):  
Johannes Riemenschneider ◽  
Oliver Huxdorf ◽  
Steffen Opitz
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Rotor Blades ◽  
Special Importance ◽  
Low Frequencies ◽  
Patch Type ◽  
Loop Control ◽  
Dc Voltage ◽  
Piezoceramic Actuator ◽  
Static Conditions

In the field of smart structures, piezoceramic actuators are wildly used for vibration reduction and acoustic manipulation of structures. Those applications typically run at frequencies between 10 Hz and 10k Hz. Prominent examples are the piezoceramic actuators implemented in helicopter rotor blades to twist them dynamically for higher harmonic control (HHC) or individual blade control (IBC). Once the actuators are implemented it would be a great benefit to also use them to statically change the blade twist (higher twist for take-off and landing — for higher lift; lower twist for high speed forward flight — for reduced drag). Staying with this example it can be found that sensing the twist displacement is not an easy task at all (see [1, 2]), so it would be most desirable, to use open loop control. In order to do that, the transfer function has to be known accurately. Unfortunately measurements show that the amplitudes for such very low frequencies behavior behave strongly non linear. This paper presents experimental results investigating the influence of the frequency on the amplitude — especially going for frequencies in the lower mHz region. A variety of piezoceramic actuators has been investigated: from stacks to patch type, d33 as well as d31 effect actuators. A second focus of this paper is the reaction of piezoceramic actuators on the application of a constant DC voltage. The drift that occurs has to be taken into consideration. A third focus of this paper is the dependency of a displacement output of such an actuator at a constant applied DC voltage on the voltages that the actuator had seen before. This topic is of special importance for aerodynamically effective surfaces that are driven by piezoceramic actuators and should be analyzed (generation of polars) in static conditions.

scholarly journals Modal Engineering for MEMS Devices: Application to Galvos and Scanners

2020 ◽  
Author(s):  
Lawrence Barrett ◽  
Matthias Imboden ◽  
Josh Javor ◽  
David K. Campbell ◽  
David J. Bishop
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Optical Systems ◽  
Control Algorithms ◽  
Mems Devices ◽  
Open Loop Control ◽  
Optical Elements ◽  
Loop Control ◽  
High Q ◽  
Change Position

Optical systems typically use galvanometers (aka galvos) and scanners. Galvos move optical elements such as mirrors, quasi-statically, from one static position to another, and an important figure of merit is their step-settle relaxation time. Scanners move in an oscillatory fashion, typically at the device resonant frequency. MEMS devices, which have many advantages and are often used in such optical systems, are typically high Q devices. Moving from one position to another for a galvo or one frequency/amplitude to another for scanners, can take many periods to settle following the ring down. During these transitions, the optical system is inactive and the time is not being efficiently used. In this article we show how a novel class of open loop control algorithms can be used to rapidly change position, frequency and amplitude, typically in well under the period of the device. We show how the MEMS designer can excite, with complete, high-speed control, a vibrational mode of the system. We call this modal engineering, the ability to control the modes of the system in a practical, fast way. This control of the modes is accomplished with open loop control algorithms.

Numerical and experimental analysis of rubbing–misalignment mixed fault in a dual-rotor system

2020 ◽  
pp. 095440622096858
Author(s):  
Wenzhen Xie ◽  
Chao Liu ◽  
Nanfei Wang ◽  
Dongxiang Jiang
Keyword(s):  
High Speed ◽  
Experimental Tests ◽  
Rotor System ◽  
Dynamic Responses ◽  
System Model ◽  
Speed Ratio ◽  
Rotor Systems ◽  
Frequency Components ◽  
Aero Engines ◽  
Misalignment Fault

Dual-rotor systems are widely used in aero-engines, in which rubbing–misalignment mixed faults are essential, as both are frequently observed and can occur simultaneously due to the harsh working conditions of high temperature, high pressure, and high speed. To analyze the vibration characteristics of such faults, a dual-rotor system model is established and dynamic responses under varying parameters of the dual-rotor system with rubbing–misalignment mixed fault are investigated. Through numerical simulation, the effects of speed ratio, rubbing clearance, and rubbing stiffness on the dual-rotor system with rubbing–misalignment fault are revealed. Meanwhile, experimental tests are conducted for validation, the main findings of which are that the characteristic frequency components could benefit the diagnosis of mixed faults in dual-rotor systems.

Rotor Dynamics in Design of a High Speed Cryogenic Pump for Geo Stationary Launch Vehicles

2014 ◽  
Author(s):  
Srinivasa R. Jammi
Keyword(s):  
High Speed ◽  
Rotor Dynamics ◽  
Rotor System ◽  
Peak Amplitude ◽  
Beam Model ◽  
Rolling Element Bearings ◽  
Launch Vehicles ◽  
Critical Speeds ◽  
Highly Nonlinear ◽  
Rolling Element

On January 5th 2014 the Indian Space Research Organization successfully launched its Geo Stationary Launch Vehicle with an indigenous Cryogenic engine. One of the main design aspects is in its rotor dynamics to predict the peak amplitude unbalance whirl and the speed at which it occurs. This engine has several key technologies, one of them specifically is coupled rotors, viz., Turbine, Hydrogen Pump and Oxidizer supported on seven nonlinear rolling element bearings and several seals all mounted in a flexible casing. The conventional beam model initially adopted failed to predict the speed at which peak unbalance response occurs. The rotor system was first developed in a solid model to determine the critical speeds of the rotor alone considering its 40000 rpm centrifugal loads with bearings treated as linear. Then, unbalance whirl of this rotor system was developed by codes specially developed for this purpose. The rolling element bearings are found to be highly nonlinear with large bearing radial forces at critical speeds. An iterative procedure was developed to match the bearing force and unbalance whirl to determine peak amplitude response speeds. Subsequently, seals and the influence of casing and internal pressures were accounted in the analysis. This paper describes the advanced rotor dynamic design of this pump.

scholarly journals Response of High-Pressure Micro Water Jets to Static and Dynamic Nonuniform Electric Fields

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
High Pressure ◽  
Electric Fields ◽  
High Speed ◽  
Water Jet ◽  
Dynamic Responses ◽  
Order System ◽  
Loop Control ◽  
Time Frequency ◽  
Water Jets ◽  
The Stability

The manipulation of the trajectory of high-pressure micro water jets has the potential to greatly improve the accuracy of water jet related manufacturing processes. An experimental study was conducted to understand the basic static and dynamic responses of high-pressure micro water jet systems in the presence of nonuniform electric fields. A single electrode was employed to create a nonuniform electric field to deflect a high-pressure micro water jet toward the electrode by the dielectrophoretic force generated. The water jet's motions were precisely recorded by a high-speed camera with a 20× magnification and the videos postprocessed by a LabVIEW image processing program to acquire the deflections. The experiments revealed the fundamental relationships between three experimental parameters, i.e., voltage, pressure, and the distance between the water jet and the electrode and the deflection of the water jet in both nonuniform static and dynamic electric fields. In the latter case, electric signals at different frequencies were employed to experimentally investigate the jet's dynamic response, such as response time, frequency, and the stability of the water jet's motion. A first-order system model was proposed to approximate the jet's response to dynamic input signals. The work can serve as the basis for the development of closed-loop control systems for manipulating the trajectory of high-pressure micro water jets.

Research on Novel Self-Spinning High Speed On/Off Valve Based on Fuzzy-Logic Parameter Self-Tuning PID Controller

2012 ◽  
Vol 468-471 ◽  
pp. 1448-1452 ◽  
Author(s):  
Jian Chen ◽  
Jian Ping Shu ◽  
Mian Li ◽  
Qi Zhou ◽  
Zhu Ming Su
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Pid Controller ◽  
High Speed ◽  
Position Control ◽  
Open Loop ◽  
Axial Position ◽  
Valve Body ◽  
Loop Control ◽  
Self Tuning

The flow rate of a novel self-spinning high speed hydraulic on/off valve is regulated by changing the relative axial position (the duty cycle) of the valve spool to the nozzles located on the valve body through driving a gerotor pump using brushless direct current motor. The closed loop axial position control system of the valve spool with feedback of the axial displacement of the valve spool has shorter response time, and not more ripple of output pressure than corresponding open loop control system. A fuzzy logic parameter self-tuning PID controller is investigated to overcome nonlinearity of the control system. The simulation results show that the overshoot is decreased greatly than conventional PID controller.

scholarly journals Turbulent boundary layer under the control of different schemes

2017 ◽  
Vol 473 (2202) ◽  
pp. 20170038 ◽  
Author(s):  
Z. X. Qiao ◽  
Y. Zhou ◽  
Z. Wu
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
High Speed ◽  
Control Strategies ◽  
Local Maximum ◽  
Open Loop ◽  
Open Loop Control ◽  
Feed Forward ◽  
Loop Control ◽  
Combined Feed

This work explores experimentally the control of a turbulent boundary layer over a flat plate based on wall perturbation generated by piezo-ceramic actuators. Different schemes are investigated, including the feed-forward, the feedback, and the combined feed-forward and feedback strategies, with a view to suppressing the near-wall high-speed events and hence reducing skin friction drag. While the strategies may achieve a local maximum drag reduction slightly less than their counterpart of the open-loop control, the corresponding duty cycles are substantially reduced when compared with that of the open-loop control. The results suggest a good potential to cut down the input energy under these control strategies. The fluctuating velocity, spectra, Taylor microscale and mean energy dissipation are measured across the boundary layer with and without control and, based on the measurements, the flow mechanism behind the control is proposed.

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