scholarly journals Improving the Stability of the Passenger Vehicle by Using an Active Stabilizer Bar Controlled by the Fuzzy Method

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Tuan Anh Nguyen
Keyword(s):  
High Speed ◽  
Control Method ◽  
Spatial Dynamics ◽  
The Body ◽  
Vertical Force ◽  
Dynamics Model ◽  
Track Dynamics ◽  
The Difference ◽  
Lift Off ◽  
The Stability

The rollover phenomenon is a particularly dangerous problem. This phenomenon occurs when the driver travels at high speed and suddenly steers. Under the influence of centrifugal force, the body vehicle will be tilted and cause the wheels to lift off the road. To solve this problem, the method of using an active stabilizer bar has been proposed. The active stabilizer bar is controlled automatically by a previously designed controller. The performance of the active stabilizer bar depends on the selected control method. Previous research often only used a half-car dynamics model combined with a linear single-track dynamics model to simulate the vehicle’s oscillation. In addition, most of the research focuses only on the use of linear control methods for the active stabilizer bar. Therefore, the performance of the stabilizer bar is not guaranteed. This paper focuses on establishing the model of spatial dynamics combined with the nonlinear double-track dynamics model that fully describes the vehicle’s oscillation most accurately. Besides, the fuzzy control method is proposed to control the operation of the hydraulic stabilizer bar. This is a completely novel model, and it is suitable for the actual traveling conditions of the vehicle. Also, simulations are done based on different scenarios. The results of the paper showed that the values of the roll angle, the difference in the vertical force at the wheels, and the displacement of the unsprung mass were significantly reduced when the vehicle used the active stabilizer bar, which is controlled by an intelligent control method. Therefore, the stability and safety of the vehicle have been guaranteed. This result will be the basis for performing other more complex research in the future.

Stability Enhancement of Supercavitating Projectiles by Unsteady Air Injection

2005 ◽  
Author(s):  
Yasmin Khakpour ◽  
Miad Yazdani
Keyword(s):  
Numerical Simulation ◽  
Drag Reduction ◽  
High Speed ◽  
The Body ◽  
Air Injection ◽  
Cavity Surface ◽  
The Stability ◽  
Stability Enhancement

In this work, numerical simulation is used to study the stability enhancement of high speed supercavitating hydrofoils. Although supercavitation is known as one of the most effective methods for drag reduction, producing the cavity, either by ventilation or by cavitator at front of the body, may cause some instabilities on cavity surface and thus on the projectile’s motion. Therefore removing these instabilities comes as an important point of discussion. First of all, we calculate the sources of instabilities and measure respective forces and then present some approaches that significantly reduce these instabilities. One of these methods that could produce more stable supercavities is injecting of the air into the cavity unsteadily which varies through the projectile’s surface. This approach is provided by arrays of slots distributed on the projectile’s surface and unsteady injection is modeled over the surface. Furthermore, the position of ventilation, dramatically affects the stability like those in aerodynamics. In all approaches it is assumed that the supercavity covers the whole of the body, however the forces caused by the wakes, formed behind the body are taken into account. The calculation is performed at three cavitation numbers with respective velocities of 40 m/s, 50 m/s, 60 m/s.

scholarly journals Assessment of vehicle brake control functional stability

2021 ◽  
Vol 12 (2) ◽  
pp. 33-44
Author(s):  
Volodymyr Volkov ◽  
◽  
Igor Gritsuk ◽  
Tetiana Volkova ◽  
Volodymyr Kuzhel ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Control Method ◽  
Operating Conditions ◽  
National Standards ◽  
Passenger Vehicles ◽  
The Difference ◽  
Braking Control ◽  
The Stability ◽  
Friction Surfaces

The article is devoted to the study of the influence of the brake control elements of passenger vehicles on the stability of their braking properties. The analysis of the influence of uneven braking forces on the wheels of one axle of vehicles on the deviation of the distribution of braking forces between the axles from its calculated value is carried out. When assessing the error in regulating the distribution of braking forces between the axles of vehicles, three components were taken into account: the theoretical error due to the imperfection of the selected control method (the difference between the actual calculated control characteristic from the ideal), the error created due to the instability of the ratio of the braking forces on the front and rear wheels, an additional error caused by the unevenness of the braking forces on the wheels of individual axles, since the fulfillment of the most stringent requirements of international and national standards for the efficiency of braking of vehicles and is inextricably linked with the need to increase the energy consumption of brake mechanisms. The energy consumption of braking mechanisms is understood as the ability of the latter to dissipate the greatest amount of energy of the braking machine without reducing the braking efficiency indicators to the minimum permissible level. Excessive heating of the braking mechanisms leads to a decrease in the friction coefficient μ of the friction surfaces and increased wear of the friction linings, and the brakes are the most unstable element of the braking control, which ensures the absorption and dissipation of the vehicle's energy during braking. The instability of the braking torques on the front and rear wheels, caused by a change in the coefficients of friction of friction pairs, leads not only to a change in the distribution of braking forces between the axles and individual wheels, but also to a decrease in the braking efficiency of vehicles under operating conditions. A method is proposed that makes it possible to assess the quality of regulation of the distribution of braking forces between the axles of a car, taking into account the instability of the braking forces on the wheels.

A comparative study on the breakup of Newtonian and viscoelastic liquid films

2018 ◽  
Vol 32 (12n13) ◽  
pp. 1840032
Author(s):  
Lijuan Qian ◽  
Shaobo Song ◽  
Lisha Jiang ◽  
Xiaolu Li ◽  
Jianzhong Lin
Keyword(s):  
Liquid Film ◽  
High Speed ◽  
Liquid Films ◽  
Viscoelastic Liquid ◽  
Ligament Length ◽  
Time Resolved ◽  
Liquid Bubble ◽  
Mean Size ◽  
The Difference ◽  
The Stability

The breakup of viscoelastic liquid films are investigated experimentally and analytically. The breakup phenomena of viscoelastic liquid film are recorded by the time resolved high speed camera. Video images reveal the difference behavior of liquid bubble breakup for Newtonian and viscoelastic liquid. For the Newtonian liquid, cylindrical ligaments are stretched into droplets with large distributions of drop size. For the viscoelastic liquid, the pinch-off point is located on the liquid connections to the nozzle and finally the main part of the ligament no longer elongates. Furthermore, a dispersion relation based on the stability analysis is involved to predict the ligament length and drop mean size after breakup for liquid film. The calculated ligament length is validated by the measured drop mean size at higher air-to-liquid mass flow ratio.

Dynamics modeling and analysis of a four-wheel independent motor-drive virtual-track train

2020 ◽  
pp. 146441932096401
Author(s):  
Zhonghui Yin ◽  
Jiye Zhang ◽  
Haiying Lu ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Spatial Dynamics ◽  
Dynamic Responses ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Coupling Effects ◽  
Dynamic Interactions ◽  
Modeling And Analysis

Due to urbanisation and the economic challenges of traffic, it is urgently necessary to develop an environmentally friendly virtual-track train with suitable speed, high load capacity and low construction cost in China. To guide the design and evaluate this train’s dynamic behaviour, a spatial-dynamics model has been developed based on the dynamics theory and tyre-road interaction. The proposed dynamics model comprises mechanical vehicle systems, traction and braking characteristics and tyre-road dynamic interactions. The coupling effects amongst those systems of virtual track train are derived theoretically for the first time. The nonlinear characteristics of the tyre are modelled by the transit tyre-magic formula with consideration of road irregularities. Based on a designed PID controller and the comprehensive dynamics model, the dynamic performance of the system can be revealed considering motion coupling effects and complicated excitations, especially under traction and braking conditions. The dynamic responses of whole virtual track train can be obtained by numerical integration under different conditions. The vibration characteristics of such train are assessed under running at a constant speed and during the traction/braking process. The results show that the vibrations of the vehicle system are significantly influenced by road irregularities, especially at high speed ranges. The motions and vibrations of different components are intensive coupled, which should not to be neglected in the dynamics assessment of the virtual track train. Besides, the dynamics model can also be applied to dynamics-related assessment (fatigue, strength and some damage conditions, et al.) and parameter optimisation of the virtual-track train.

Impedance Control of Gyroscopic Power Generator

2011 ◽  
Author(s):  
Tomoyuki Takahashi ◽  
Jun Iwasaki ◽  
Hiroshi Hosaka
Keyword(s):  
Steady State ◽  
Phase Difference ◽  
High Speed ◽  
Control Method ◽  
Impedance Control ◽  
Low Frequency ◽  
Power Generator ◽  
Communication Devices ◽  
High Speed Rotation ◽  
The Stability

The gyroscopic power generator produces a high-speed rotation of magnets from low-frequency vibrations and supplies electric power to information and communication devices that use human vibrations in daily life. In this paper, in order to increase the stability and the output power of the generator, a simple equation that indicates the steady state approximate solution of the phase difference is derived. From the derived solution, a control method for the steady state is verified by the simulations. In order to maintain the stability and high power generation for variable input vibrations, the impedance control method using the phase difference is developed and verified experimentally.

scholarly journals Luenberger Position Observer Based on Deadbeat-Current Predictive Control for Sensorless PMSM

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1325 ◽  
Author(s):  
Yuan Zhu ◽  
Ben Tao ◽  
Mingkang Xiao ◽  
Gang Yang ◽  
Xingfu Zhang ◽  
...  
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
High Speed ◽  
Control Method ◽  
Permanent Magnet Synchronous Motor ◽  
Current Control ◽  
Luenberger Observer ◽  
Control Step ◽  
The Stability ◽  
Discrete Mathematical Model

Two problems can cause control performance degradation on permanent magnet synchronous motor (PMSM) systems, namely, fluctuation of PMSM parameters and the time delay between current sampling and command value update. In order to reduce the influence of these problems, a new current-predictive control strategy is proposed in this article for medium- and high-speed PMSM. This strategy is based on the discrete mathematical model of PMSM. This new control strategy consists of two main steps: First, an integrator is applied to calculate current compensation value; second, the predictive current value is obtained through deadbeat-current predictive method. The stability of predictive control system is also proved in the article. With this deadbeat-current predictive control scheme, the real current can reach the desired value within one control-step. Based on this new current control method, Luenberger observer and phase-locked loop position tracker is applied in this article. Experimental results for 0.4 kW surface-mounted PMSM confirm the validity and excellent performance for parameters fluctuation of new current predictive control.

Review on Main Drive Torsional Vibration and Roller Coupling Vibration of Rolling Mill

2020 ◽  
Vol 14 ◽  
Author(s):  
Xiao-bin Fan ◽  
Bin Zhao ◽  
Yu Jiang ◽  
Bing-Xu Fan
Keyword(s):  
Rolling Mill ◽  
High Speed ◽  
Control Method ◽  
Hot Spot ◽  
Rolling Process ◽  
Coupling Vibration ◽  
Non Linear ◽  
Roll System ◽  
The Stability ◽  
Rolling Mill Vibration

Background: Rolling mill vibration has become one of the most widespread and unsolved problems in rolling industry, which is called "Ghost" vibration. The research on the starting mechanism, vibration characteristics and vibration suppression measures of high-speed tandem rolling mill has always been a hot spot and difficult point in the field of rolling at home and abroad. However, up to now, the research on rolling mill vibration has not formed a relatively complete and widely accepted theoretical system, experimental means and solutions. In production, vibration is often controlled by experience and test, which has high cost and low efficiency. Methods: In this paper, the research history and achievements of vibration phenomena, vibration mechanism, stability of rolling process and vibration control theory of high-speed tandem rolling mill in recent years are summarized. The aim is to reveal the mechanism of rolling mill vibration in continuous rolling process, the mechanism of rolling mill non-linear vibration instability and its changing law, and to explore the optimization of rolling process and the control method of rolling mill structure so as to improve the rolling process. Results: The evolution of non-linear random torsional / bending vibration and its transfer mechanism to the space coupling vibration of the roll system, the unsteady dynamic friction characteristics of the rolling interface and the mechanism of induced roll chatter, and the non-linear random dynamic behavior of the space coupling vibration of the roll system are revealed. Conclusion: The stability of rolling process can realize the research and development of high-end products considering the stability of rolling process, and also provide reference for further research by industry experts.

Torque control of new energy four wheel hub motor based on distribution algorithm

2021 ◽  
pp. 29-41
Author(s):  
Shuai Leng ◽  
◽  
Liqiang Jin ◽  
Keyword(s):  
Control Method ◽  
The Body ◽  
Torque Control ◽  
State Variables ◽  
Motor Speed ◽  
Control Effect ◽  
New Energy ◽  
Optimal Efficiency ◽  
Stator Flux ◽  
The Stability

Due to the nonlinear, strong coupling and uncertain parameters of the new energy four-wheel hub motor, it is more difficult to control the torque of the motor. In order to solve this problem, a torque control method of the new energy four-wheel hub motor based on the distribution algorithm is proposed. The dynamic model of the new energy four-wheel hub motor is established, and the unmeasurable flux, electric power and other state variables in the motor model are derived according to the degree of freedom of the body. The whole four-wheel hub motor is taken as the research object, and the optimal efficiency of the drive system is taken as the goal, and the distribution algorithm is used to control the electromagnetic torque of the motor. The simulation results show that after the torque control of new energy four wheel hub motor, the driving range of the vehicle is longer, the amplitude of stator flux changes little, the stator current changes and the stability of motor speed are good, and the torque control effect is better.

scholarly journals Time-resolved vortex wake of a common swift flying over a range of flight speeds

2010 ◽  
Vol 8 (59) ◽  
pp. 807-816 ◽  
Author(s):  
P. Henningsson ◽  
F. T. Muijres ◽  
A. Hedenström
Keyword(s):  
High Speed ◽  
Particle Image ◽  
Digital Particle Image Velocimetry ◽  
Transverse Plane ◽  
The Body ◽  
Vortex Wake ◽  
Vertical Force ◽  
Time Resolved ◽  
Longitudinal Plane ◽  
Image Velocimetry

The wake of a freely flying common swift ( Apus apus L.) is examined in a wind tunnel at three different flight speeds, 5.7, 7.7 and 9.9 m s −1 . The wake of the bird is visualized using high-speed stereo digital particle image velocimetry (DPIV). Wake images are recorded in the transverse plane, perpendicular to the airflow. The wake of a swift has been studied previously using DPIV and recording wake images in the longitudinal plane, parallel to the airflow. The high-speed DPIV system allows for time-resolved wake sampling and the result shows features that were not discovered in the previous study, but there was approximately a 40 per cent vertical force deficit. As the earlier study also revealed, a pair of wingtip vortices are trailing behind the wingtips, but in addition, a pair of tail vortices and a pair of ‘wing root vortices’ are found that appear to originate from the wing/body junction. The existence of wing root vortices suggests that the two wings are not acting as a single wing, but are to some extent aerodynamically detached from each other. It is proposed that this is due to the body disrupting the lift distribution over the wing by generating less lift than the wings.

scholarly journals Novel Design of a Biaxial and Four-Wheeled Robot Capable of Steering

2018 ◽  
Vol 160 ◽  
pp. 06006
Author(s):  
Guiping Lan ◽  
Yujun Wang ◽  
Can Fang ◽  
Min Yi
Keyword(s):  
Control Method ◽  
Experimental Results ◽  
Phase Method ◽  
Mechanical Structure ◽  
Wheeled Robot ◽  
The Difference ◽  
The Stability ◽  
Novel Design

The paper presents a biaxial and four-wheeled robot, mainly composed of two axle, two circular wheels and two three-leaved wheels. By analyzing the difference between the velocity of the circular wheel and three-leaved wheel in same axle, the steering principle of the difference velocity is proved. The three-leaved wheels are installed by a complementary phase method to ensure the stability of the robot walking. Through the steering principle, the control method of robot’s forward, backward, turn left and turn right is designed. A large number of experimental results show that the robot has the characteristics of high steering efficiency, simple mechanical structure and easy to control.

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