scholarly journals Time-Delay Vibration Reduction Control of 3-DOF Vehicle Model with Vehicle Seat

2021 ◽  
Vol 11 (20) ◽  
pp. 9426
Author(s):  
Kaiwei Wu ◽  
Chuanbo Ren ◽  
Yuanchang Chen
Keyword(s):  
Time Delay ◽  
Performance Optimization ◽  
Low Frequency ◽  
Active Suspension ◽  
Random Excitation ◽  
Feedback Gain ◽  
Time Interval ◽  
On The Road ◽  
The Stability ◽  
Vehicle Seat

Vehicles driving on the road continuously suffer low-frequency and high-intensity road excitation, which can cause the occupant feelings of tension and dizziness. To solve this problem, a three-degree-of-freedom vehicle suspension system model including vehicle seat is established and a linear function equivalent excitation method is proposed. The optimization of the random excitation is transformed into the optimization of constant force in a discrete time interval, which introduces the adaptive weighted particle swarm optimization algorithm to optimize the delay and feedback gain parameters in the feedback control of time delay. In this paper, the stability switching theory is used for the first time to analyze the stability interval of 3-DOF time-delay controlled active suspension, which ensures the stability of the control system. The numerical simulation results show that the algorithm can reduce vertical passenger acceleration and vehicle acceleration, respectively, by 13.63% and 28.38% on average, and 29.99% and 47.23% on random excitation, compared with active suspension and passive suspension based on inverse control. The effectiveness of the method to suppress road random interference is verified, which provides a theoretical reference for further study of suspension performance optimization with time-delay control.

Gobal Optimization Based Power System Stablization with WAMS Time Delay Study

2012 ◽  
Vol 433-440 ◽  
pp. 7362-7367
Author(s):  
Zhang Lin ◽  
Di Chen Liu ◽  
Wu Jun ◽  
Qing Fen Liao ◽  
Yun Lei ◽  
...  
Keyword(s):  
Global Optimization ◽  
Time Delay ◽  
Power System ◽  
Low Frequency ◽  
System Stability ◽  
Area Measurement ◽  
Wide Area ◽  
Linear Matrix ◽  
Feedback Signal ◽  
The Stability

It is very important to take into consideration time delay in wide area power system stability; the design of PSS (Power System Stabilizer) should consider global optimization with WAMS (Wide Area Measurement System) time delay. Newly designed PSS should be insensitive to time delay and suppress internal low frequency oscillations. It is used as feedback signal and is real-time synchronous that WAMS signal shows. Power system is modeled with the consideration of time delay. LMI (Linear Matrix Inequalities) is used to solve the stability condition of time delay system. Based on the time-delay effect of the wide-area measurement signals, this paper redesigned the PSS with global optimization of power system. The attached two-area-four-machine system simulation illustrates that wide-area PSS designed by global optimization with the consideration of time-delay can limit internal low frequency oscillation with time-delay insensitivity, and improve the stability of power system. It implements global optimization of PSS with WAMS time delay stability.

Chaos Suppression via Integrative Time Delay Control

2020 ◽  
Vol 30 (14) ◽  
pp. 2050208
Author(s):  
Ayman A. Arafa ◽  
Yong Xu ◽  
Gamal M. Mahmoud
Keyword(s):  
Time Delay ◽  
Chaotic System ◽  
Chaotic Systems ◽  
Time Interval ◽  
General Strategy ◽  
Normal Form Theory ◽  
Chaos Suppression ◽  
Form Theory ◽  
The Stability ◽  
Time Delayed Feedback

A general strategy for suppressing chaos in chaotic Burke–Shaw system using integrative time delay (ITD) control is proposed, as an example. The idea of ITD is that the feedback is integrated over a time interval. Physically, the chaotic system responds to the average information it receives from the feedback. The main feature of integrative is that the stability of the chaotic system occurs over a wider range of the space parameters. Controlling chaotic systems with ITD has not been discussed before as far as we know. Stability and the existence of Hopf bifurcation are studied which demonstrate that the switch stability occurs at critical values of the time delay. Employing the normal form theory and center manifold argument, an explicit formula is derived to determine the stability and the direction of the bifurcating periodic solutions. Numerically, the bifurcation diagram and the eigenvalues of the corresponding characteristic equations are computed to supply a clear interpretation for suppressing chaos via ITD. Furthermore, ITD method is compared with the time delayed feedback (TDF) control numerically. This comparison shows that the stability area with ITD is larger than TDF which demonstrates the feasibility and effectiveness of the ITD. Other examples of chaotic systems can be similarly investigated.

scholarly journals Multiobjective Optimization of Nonlinear Active Suspension System with Time-Delayed Feedback

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Su-Juan Shao ◽  
Dong Jing ◽  
Chuan-Bo Ren
Keyword(s):  
Time Delay ◽  
Multiobjective Optimization ◽  
Ride Comfort ◽  
Active Suspension ◽  
Suspension System ◽  
Function Optimization ◽  
Driving Safety ◽  
Optimal Time ◽  
Feedback Parameter ◽  
The Stability

Considering the nonlinear properties of spring and damping of suspension, a quarter-car model with time-delayed control is established. The Routh–Hurwitz stability criterion and stability switching method are used to analyze the stability of the system and obtain the stability region diagram. The multiobjective optimization function is established by considering the ride comfort, driving safety, and handling stability. The optimal control parameters are obtained by the optimization and simulation of the system under harmonic excitation and random excitation. In addition, the responses of the active suspension system with optimal time-delay control and the passive suspension system without control are compared. The results show that the active suspension system with time-delay displacement feedback control can reduce the vibration of the system, and there is an optimal feedback parameter combination to optimize the vehicle running state. The design of multiobjective function optimization proposed in this paper can improve ride comfort, driving safety, and handling stability and provide guidance for comprehensively improving vehicle performance.

THE RESONANCE METHOD OF MEASURING THE RATIO OF THE SPECIFIC HEATS OF A GAS, Cp/Cv: PART V: SECTION A: AN IMPROVED APPARATUS FOR MEASURING THE RATIO OF THE SPECIFIC HEATS OF A GAS: SECTION B: THE USE OF ELECTRONIC COUNTER CIRCUITS TO MEASURE LOW FREQUENCIES AND A VARIABLE LOW FREQUENCY OSCILLATOR

1949 ◽  
Vol 27a (3) ◽  
pp. 27-38 ◽  
Author(s):  
L. Katz ◽  
S. B. Woods ◽  
W. F. Leverton
Keyword(s):  
Specific Heat ◽  
Low Frequency ◽  
Resonance Method ◽  
Time Interval ◽  
Low Frequencies ◽  
Specific Heats ◽  
Wide Range ◽  
New Apparatus ◽  
The Stability ◽  
Number Of Cycles

This paper describes an improved apparatus for the determination of γ = Cp/Cv, the ratio of the specific heat at constant pressure to the specific heat at constant volume for a gas. With this apparatus, γ is determined by the resonance method of Clark and Katz. The new apparatus is constructed of stainless steel and is designed to withstand pressures up to 100 atm. This new apparatus is more compact and can be used with corrosive gases. Provision is made for the control and accurate measurement of the temperature of the enclosed gas over a wide range of temperatures. An electronic counter which will measure time intervals, in units of 10 μsec., from 100 μsec. to several seconds in length is described in Section B. An unknown frequency may be determined by measuring the time interval in which a preselected number of cycles occurs. The accuracy is such that frequencies may be measured to within approximately 1 part in 105. The circuit for a variable frequency transitron oscillator with an output of 30 w. in a range of 15 to 250 c.p.s. is shown. The stability of the oscillator is such that the frequency may easily be maintained within 1 part in 10,000 for long periods, and with care in temperature control and choice of electrode voltages much greater stabilities may be obtained.

Stability Analysis of Parametrically Excited Systems With Time-Delay

2003 ◽  
Author(s):  
Eric A. Butcher ◽  
Haitao Ma ◽  
Ed Bueler ◽  
Victoria Averina ◽  
Zsolt Szabo
Keyword(s):  
Time Delay ◽  
Integral Form ◽  
Original System ◽  
Time Interval ◽  
Linear Difference Equations ◽  
Direct Integral ◽  
Parametrically Excited ◽  
Stability Matrix ◽  
The Stability ◽  
Time Periodic

This paper presents a new technique for studying the stability properties of parametrically excited dynamic systems with time delay modeled by delay-differential equations (DDEs) with time-periodic parameters. By employing a shifted Chebyshev polynomial approximation in each time interval with length equal to the delay period, the dynamic system can be reduced to a set of linear difference equations for the Chebyshev expansion coefficients of the state vector in the previous and current intervals. This defines a linear map which is the “infinite-dimensional Floquet transition matrix U”. Two different formulas for the computation of the approximate U, whose size is determined by the number of polynomials employed, are given. The first one, which results in a numerical stability matrix, uses the direct integral form of the original system in state space form while the second, which can give a symbolic stability matrix in terms of parameters, uses a convolution integral (variation of parameters) formulation. An extension of the method to the case where the delay and parametric periods are commensurate is also available. Numerical and symbolic stability charts are produced for several examples of time-periodic DDEs, including the delayed Mathieu equation and a model for regenerative chatter in impedance-modulated turning. The results indicate that this method is a effective way to study the stability of periodic DDEs.

scholarly journals Control and Stability Analysis of Double Time-Delay Active Suspension Based on Particle Swarm Optimization

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Kaiwei Wu ◽  
Chuanbo Ren
Keyword(s):  
Particle Swarm Optimization ◽  
Time Delay ◽  
Feedback Control ◽  
Performance Optimization ◽  
Particle Swarm ◽  
Active Suspension ◽  
Swarm Optimization ◽  
Scanning Method ◽  
Delay Feedback Control ◽  
Double Time

With the application of an active control unit in the suspension system, the phenomenon of time delay has become an important factor in the control system. Aiming at the application of time-delay feedback control in vehicle active suspension systems, this paper has researched the dynamic behavior of semivehicle four-degree-of-freedom structure including an active suspension with double time-delay feedback control, focusing on analyzing the vibration response and stability of the main vibration system of the structure. The optimal objective function is established according to the amplitude-frequency characteristics of the system, and the optimal time-delay control parameters are obtained by using the particle swarm optimization algorithm. The stability for active suspension with double time-delay feedback control by frequency-domain scanning method is analyzed, and the simulation model of active suspension with double time delay based on feedback control is finally established. The simulation results show that the active suspension with double time-delay feedback control could reduce the body’s vertical vibration acceleration, pitch acceleration, and other indicators significantly, whether under harmonic excitation or random excitation. So, it is indicating that the active suspension with double time-delay feedback control has a better control effect in improving the ride comfort of the car, and it has important reference value for further research on suspension performance optimization.

On the stability of a class of nonlinear time delay systems

1999 ◽  
Author(s):  
Dan Ivancscu ◽  
Silviu-Iulian Niculcscu ◽  
Jcan-Michcl Dion ◽  
Luc Dugard
Keyword(s):  
Time Delay ◽  
Delay Systems ◽  
Time Delay Systems ◽  
The Stability

Statistical Management of Food Production Processes

2020 ◽  
pp. 30-35
Author(s):  
N.A. Jurk ◽  
Keyword(s):  
Production Process ◽  
Control Chart ◽  
Food Production ◽  
Time Interval ◽  
Bakery Products ◽  
Shewhart Control ◽  
Manufactured Products ◽  
Mnemonic Technique ◽  
The Stability

The article presents scientific research in the field of statistical controllability of the food production process using the example of bakery products for a certain time interval using statistical methods of quality management. During quality control of finished products, defects in bakery products were identified, while the initial data were recorded in the developed form of a checklist for registering defects. It has been established that the most common defect is packaging leakage. For the subsequent statistical assessment of the stability of the production process and further analysis of the causes of the identified defect, a Shewhart control chart (p-card by an alternative feature) was used, which allows you to control the quality of manufactured products by the number of defects detected. Analyzing the control chart, it was concluded that studied process is conditionally stable, and the emerging defects are random. At the last stage of the research, the Ishikawa causal diagram was used, developed using the 6M mnemonic technique, in order to identify the most significant causes that affect the occurrence of the considered defect in bakery products. A more detailed study will allow the enterprise to produce food products that meet the established requirements.

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