scholarly journals Assessment of the Magnetic Hysteretic Behaviour of MR Dampers through Sensorless Measurements

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Janusz Gołdasz ◽  
Bogdan Sapinski ◽  
Łukasz Jastrzębski
Keyword(s):  
Magnetic Hysteresis ◽  
Operating Conditions ◽  
Effective Control ◽  
Flow Mode ◽  
Shear Mode ◽  
Hysteretic Behaviour ◽  
Mr Dampers ◽  
Smart Fluids ◽  
Wide Range ◽  
And Control

Magnetorheological (MR) dampers are well-known devices based on smart fluids. The dampers exhibit nonlinear hysteretic behaviour which affects their performance in control systems. Hence, an effective control scheme must include a hysteresis compensator. The source of hysteresis in MR dampers is twofold. First, it is due to the compressibility and inertia of the fluid. Second, magnetic hysteresis is the inherent property of ferromagnetic materials that form the control circuit of the valve including MR fluid. While the former was studied extensively over the past years using various phenomenological models, the latter has attracted less attention. In this paper, we analyze the magnetic hysteretic behaviour of three different MR dampers by investigating their current-flux relationships. Two dampers operate in flow mode, whereas the third one is a shear-mode device (brake). The approach is demonstrated using a sensorless magnetic flux estimation technique. We reveal the response of the dampers when subjected to sinusoidal inputs across a wide range of operating conditions and excitation inputs. Our observations of the flux data showed that the hysteresis is influenced by both amplitude and the frequency of the excitation input. The procedure allows to analyze the magnetic hysteresis independently of other sources of hysteresis in MR dampers; on this basis, more effective damper models and control algorithms can be developed in the future.

Modeling the Effects of Variable Intake Valve Timing on Diesel HCCI Combustion at Varying Load, Speed, and Boost Pressures

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
C. L. Genzale ◽  
S.-C. Kong ◽  
R. D. Reitz
Keyword(s):  
Operating Conditions ◽  
Effective Control ◽  
Intake Valve ◽  
Valve Timing ◽  
Detailed Chemical Kinetics ◽  
Hcci Combustion ◽  
Wide Range ◽  
Particulate Matter Emissions ◽  
Charge Mixture ◽  
Ignition And Combustion

Homogeneous charge compression ignition (HCCI) operated engines have the potential to provide the efficiency of a typical diesel engine, with very low NOx and particulate matter emissions. However, one of the main challenges with this type of operation in diesel engines is that it can be difficult to control the combustion phasing, especially at high loads. In diesel HCCI engines, the premixed fuel-air charge tends to ignite well before top dead center, especially as load is increased, and a method of delaying the ignition is necessary. The development of variable valve timing (VVT) technology may offer an important advantage in the ability to control diesel HCCI combustion. VVT technology can allow for late intake valve closure (IVC) times, effectively changing the compression ratio of the engine. This can decrease compression temperatures and delay ignition, thus allowing the possibility to employ HCCI operation at higher loads. Furthermore, fully flexible valve trains may offer the potential for dynamic combustion phasing control over a wide range of operating conditions. A multidimensional computational fluid dynamics model is used to evaluate combustion event phasing as both IVC times and operating conditions are varied. The use of detailed chemical kinetics, based on a reduced n-heptane mechanism, provides ignition and combustion predictions and includes low-temperature chemistry. The use of IVC delay is demonstrated to offer effective control of diesel HCCI combustion phasing over varying loads, engine speeds, and boost pressures. Additionally, as fueling levels are increased, charge mixture properties are observed to have a significant effect on combustion phasing. While increased fueling rates are generally seen to advance combustion phasing, the reduction of specific heat ratio in higher equivalence ratio mixtures can also cause noticeably slower temperature rise rates, affecting ignition timing and combustion phasing. Variable intake valve timing may offer a promising and flexible control mechanism for the phasing of diesel HCCI combustion. Over a large range of boost pressures, loads, and engine speeds, the use of delayed IVC is shown to sufficiently delay combustion in order to obtain optimal combustion phasing and increased work output, thus pointing towards the possibility of expanding the current HCCI operating range into higher load points.

scholarly journals Designing Stipulated Gains of Aircraft Stability and Control Augmentation Systems for Semiglobal Trajectories Tracking

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Mostafa Y. B. Elshabasy ◽  
Yongki Yoon ◽  
Ashraf Omran
Keyword(s):  
Control Method ◽  
Simple Procedure ◽  
Operating Conditions ◽  
Stability And Control ◽  
Wide Range ◽  
Flight Envelope ◽  
The Stability ◽  
Classical Control ◽  
And Control ◽  
Aircraft Stability And Control

The main objective of the current investigation is to provide a simple procedure to select the controller gains for an aircraft with a largely wide complex flight envelope with different source of nonlinearities. The stability and control gains are optimally devised using genetic algorithm. Thus, the gains are tuned based on the information of a single designed mission. This mission is assigned to cover a wide range of the aircraft’s flight envelope. For more validation, the resultant controller gains were tested for many off-designed missions and different operating conditions such as mass and aerodynamic variations. The results show the capability of the proposed procedure to design a semiglobal robust stability and control augmentation system for a highly maneuverable aircraft such as F-16. Unlike the gain scheduling and other control design methodologies, the proposed technique provides a semi-global single set of gains for both aircraft stability and control augmentation systems. This reduces the implementation efforts. The proposed methodology is superior to the classical control method which rigorously requires the linearization of the nonlinear aircraft model of the investigated highly maneuverable aircraft and eliminating the sources of nonlinearities mentioned above.

Real-Time Burst Signal Removal Using Multicolor Pyrometry Based Filter for Improved Jet Engine Control

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Guanghua Wang ◽  
Jordi Estevadeordal ◽  
Nirm Nirmalan ◽  
Sean P. Harper
Keyword(s):  
Real Time ◽  
Operating Conditions ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Root Cause ◽  
Control Functions ◽  
Wide Range ◽  
Voltage Signal ◽  
And Control

Online line-of-sight (LOS) pyrometer is used on certain jet engines for diagnosis and control functions such as hot-blade detection, high-temperature limiting, and condition-based monitoring. Hot particulate bursts generated from jet engine combustor at certain running conditions lead to intermittent high-voltage signal outputs from the LOS pyrometer which is ultimately used by the onboard digital engine controller (DEC). To study the nature of hot particulates and enable LOS pyrometer functioning under burst conditions, a multicolor pyrometry (MCP) system was developed under DARPA funded program and tested on an aircraft jet engine. Soot particles generated as byproduct of combustion under certain conditions was identified as the root cause for the signal burst in a previous study. The apparent emissivity was then used to remove burst signals. In current study, the physics based filter with MCP algorithm using apparent emissivity was further extended to real-time engine control by removing burst signals at real time (1 MHz) and at engine DEC data rate. Simulink models are used to simulate the performances of the filter designs under engine normal and burst conditions. The results are compared with current LOS pyrometer results and show great advantage. The proposed model enables new LOS pyrometer design for improved engine control over wide range of operating conditions.

scholarly journals GE ENERGY Jenbacher gas engine technology – preventive maintenance by means of highly sophisticated control systems

2006 ◽  
Vol 125 (2) ◽  
pp. 82-86
Author(s):  
Thomas ELSENBRUCH
Keyword(s):  
Control Systems ◽  
Data Transmission ◽  
Operating Conditions ◽  
Engine Operation ◽  
Actual Operating ◽  
Wide Range ◽  
Control Concept ◽  
On Line ◽  
Optimal Adjustment ◽  
And Control

Data collection and control concept of Jenbacher gas engines has been presented in the paper. Internet data transmission allow on-line control of the engine operation, early detection of defects and optimal adjustment to engine actual operating conditions. The system offers both customers and GE Jenbacher maintenance staff a wide range of functionalities for commissioning, monitoring and maintaining installations and for diagnostic purposes.

Semi-active MR dampers for seismic control of structures

2009 ◽  
Vol 42 (3) ◽  
pp. 157-166 ◽  
Author(s):  
Jagadish G. Kori ◽  
R.S. Jangid
Keyword(s):  
Structural Response ◽  
Mr Damper ◽  
Control Algorithms ◽  
Shear Mode ◽  
Control Force ◽  
Base Shear ◽  
Seismic Control ◽  
Mr Dampers ◽  
Wide Range ◽  
Input Command

Magnotorheological (MR) dampers have been demonstrated to be more effective in reducing the structural response due to earthquakes using only a small amount of external power. The performance of MR damper depends upon type of control law used and the damper force is directly depends on the input command voltage. The purpose of this study is to evaluate the effectiveness of input command voltage on MR damper system against recently proposed control laws under different earthquakes. The magnitude of control force increases with the increase in the input command voltage of MR damper, however for the different damper locations and configurations maximum command voltage to the current driver may not always effective in reducing the structural responses. To investigate the effective performance of the MR dampers, different control algorithms with multiple MR damper locations are considered in this study. A phenomenological model of a shear- mode MR damper, based on a Bouc–Wen element, is employed in the analysis of the controlled building. The control algorithms are tested on a five-story framed building and parametric study on variation in the input command voltage is conducted for different real earthquake ground motions. The numerically evaluated optimum parametric values are considered for the analysis of the different damper locations in the building in order to reduce the displacement, acceleration and the base shear of the building. It is shown numerically that the performance of the MR damper has a great potential in suppressing structural vibrations over a wide range of seismic inputs by selecting appropriate optimum input command voltages.

scholarly journals Choice of Interceptor Aerodynamic Lifting Surface Location based on Autopilot Design Considerations

2021 ◽  
Vol 71 (1) ◽  
pp. 108-116
Author(s):  
Ram B. Sankar ◽  
P. K. Tiwari ◽  
B. Bandyopadhyay ◽  
H. Arya
Keyword(s):  
Center Of Pressure ◽  
Static Stability ◽  
Operating Conditions ◽  
Neutral Stability ◽  
Lifting Surface ◽  
Stability Point ◽  
Wide Range ◽  
Surface Location ◽  
Optimum Aerodynamic ◽  
And Control

Interceptors operate at wide range of operating conditions in terms of Mach number, altitude and angle of attack. The aerodynamic design caters for such wide operating envelope by appropriate sizing of lifting and control surfaces for meeting the normal acceleration capability requirements. The wide range of operating conditions leads to an inevitable spread in center of pressure location and hence spread in static stability. The performance of control design is a strong function of the aerodynamic static stability. The total operating envelope can be bifurcated into statically stable and unstable zones and the aerodynamic lifting surface location can be used as a control parameter to identify the neutral stability point. During the homing phase lesser static stability is desirable for good speed of response, hence the lifting surface location needs to be chosen based on the capability of control to handle instability. This paper analyses the limitations of autopilot design for the control of an unstable interceptor and brings out a method to identify the optimum aerodynamic lifting surface location for efficiently managing static margin while satisfying the control limitations and homing phase performance. This provides an input on the most appropriate lifting surface location to the aerodynamic designer during the initial CFD based aerodynamic characterisation stage itself, before commencing the rigorous wind tunnel based characterisation.

Real-Time Burst Signal Removal Using Multi-Color Pyrometry Based Filter for Improved Jet Engine Control

2014 ◽  
Author(s):  
Guanghua Wang ◽  
Jordi Estevadeordal ◽  
Sean P. Harper ◽  
Nirm Nirmalan
Keyword(s):  
Real Time ◽  
Operating Conditions ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Root Cause ◽  
Control Functions ◽  
Wide Range ◽  
Voltage Signal ◽  
And Control

Online line-of-sight (LOS) pyrometer is used on certain jet engines for diagnosis and control functions such as hot-blade detection, high-temperature limiting, and condition-based monitoring. Hot particulate bursts generated from jet engine combustor at certain running conditions lead to intermittent high-voltage signal outputs from the LOS pyrometer which is ultimately used by the onboard Digital Engine Controller (DEC). To study the nature of hot particulates and enable LOS pyrometer functioning under burst conditions, a Multi-Color Pyrometry (MCP) system was developed under DARPA funded program and tested on an aircraft jet engine. Soot particles generated as by-product of combustion under certain conditions was identified as the root cause for the signal burst in a previous study. The apparent emissivity was then used to remove burst signals. In current study, the physics based filter with MCP algorithm using apparent emissivity was further extended to real-time engine control by removing burst signals at real time (1MHz) and at engine DEC data rate. Simulink models are used to simulate the performances of the filter designs under engine normal and burst conditions. The results are compared with current LOS pyrometer results and show great advantage. The proposed model enables new LOS pyrometer design for improved engine control over wide range of operating conditions.

scholarly journals Development of a Magnetorheological Damper with Self-Powered Ability for Washing Machines

2020 ◽  
Vol 10 (12) ◽  
pp. 4099
Author(s):  
Quoc-Duy Bui ◽  
Quoc Hung Nguyen ◽  
Tan Tien Nguyen ◽  
Duc-Dai Mai
Keyword(s):  
Energy Harvesting ◽  
Permanent Magnets ◽  
Mr Damper ◽  
Operating Conditions ◽  
Magnetorheological Damper ◽  
Shear Mode ◽  
Damping Force ◽  
Mr Dampers ◽  
Washing Machines ◽  
Self Powered

Magnetorheological (MR) dampers have been widely investigated and proposed for vibration mitigation systems because they possess continuous variability of damping coefficient in response to different operating conditions. In the conventional design of MR dampers, a separate controller and power supply are required, causing an increment of complexity and cost, which are not suitable for home appliances like washing machines. To solve these issues and to reuse wasted energy from vibration of washing machines, in this study, a self-powered shear-mode MR damper, which integrates MR damping and energy-harvesting technologies into a single device, is proposed. The MR damper is composed of an inner housing, on which magnetic coils are wound directly, and an outer housing for covering and creating a closed magnetic circuit of the damper. The gap between the inner housing and the moving shaft is filled with MR fluid to produce the damping force. The energy-harvesting part consists of permanent magnets fastened together on the shaft and induction coils wound directly on slots of the housing. The induced power from the induction coils is directly applied to the excitation coils of the damping part to generate a corresponding damping force against the vibration. In order to achieve optimal geometry of the self-powered MR damper, an optimization for both the damping part and the energy harvesting part of the proposed dampers are conducted based on ANSYS finite element analysis. From optimal solutions, a prototype of the proposed damper is designed in detail, manufactured, and experimentally validated.

scholarly journals A Driving and Control Scheme of High Power Piezoelectric Systems over a Wide Operating Range

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4401
Author(s):  
Tianyue Yang ◽  
Yuanfei Zhu ◽  
Zhiwei Fang ◽  
Haoyu Wu ◽  
Wanlu Jiang ◽  
...  
Keyword(s):  
High Power ◽  
Vibration Amplitude ◽  
Operating Conditions ◽  
Phase Detector ◽  
Displacement Sensor ◽  
Operating Range ◽  
Control Scheme ◽  
Wide Range ◽  
And Control ◽  
Wide Operating

Significant variation in impedance under a wide range of loads increases the difficulty of frequency tracking and vibration control in high-power piezoelectric systems (HPPSs). This paper proposed a wide operating range driving and control scheme for HPPSs. We systematically analyzed the impedance characteristics and deduced the load optimization frequency. In order to provide sufficient drive capability, the inverter combined with an LC matching circuit is configured. With the aid of a transformer ratio arm bridge (TRAB) combined with a proposed pulse-based phase detector (PBPD), the proposed scheme can control the vibration amplitude and keep parallel resonance status under a wide range of loads. Experiments conducted under actual operating conditions verify the feasibility of the proposed scheme under the modal resistance range from 7.40 to 500 Ω and the vibration range from 20% to 100%. Moreover, with the aid of a laser displacement sensor, our scheme is verified to have a vibration amplitude control accuracy better than 2% over a tenfold load variation. This research could be helpful for the driving and control of HPPSs operating in a wide range.

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