Study on the Straight-line Running Stability of the Four-wheel Independent Driving Electric Vehicles

2007 ◽  
Author(s):  
Zhang Huan-huan ◽  
Wang Qing-nian ◽  
Jin Li-qiang
Keyword(s):  
Electric Vehicles ◽  
Straight Line

scholarly journals Research on Decoupled Optimal Control of Straight-Line Driving Stability of Electric Vehicles Driven by Four-Wheel Hub Motors

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5766
Author(s):  
Songlin Yang ◽  
Jingan Feng ◽  
Bao Song
Keyword(s):  
Optimal Control ◽  
Electric Vehicle ◽  
Electric Vehicles ◽  
Slip Rate ◽  
Vehicle Speed ◽  
Optimal Distribution ◽  
Control Logic ◽  
Drive Torque ◽  
Straight Line ◽  
Driving Stability

The optimal control strategy for the decoupling of drive torque is proposed for the problems of runaway and driving stability in straight-line driving of electric vehicles driven by four-wheel hub motors. The strategy uses a hierarchical control logic, with the upper control logic layer being responsible for additional transverse moment calculation and driving anti-slip control; the middle control logic layer is responsible for the spatial motion decoupling for the underlying coordinated distribution of the four-wheel drive torque, on the basis of which the drive anti-skid control of a wheel motor-driven electric vehicle that takes into account the transverse motion of the whole vehicle is realized; the lower control logic layer is responsible for the optimal distribution of the driving torque of the vehicle speed following control. Based on the vehicle dynamics software Carsim2019.0 and MATLAB/Simulink, a simulation model of a four-wheel hub motor-driven electric vehicle control system was built and simulated under typical operating conditions such as high coefficient of adhesion, low coefficient of adhesion and opposing road surfaces. The research shows that the wheel motor drive has the ability to control the stability of the whole vehicle with large intensity that the conventional half-axle drive does not have. Using the proposed joint decoupling control of the transverse pendulum motion and slip rate as well as the optimal distribution of the drive force with speed following, the transverse pendulum angular speed and slip rate can be effectively controlled with the premise of ensuring the vehicle speed, thus greatly improving the straight-line driving stability of the vehicle.

Differential Control System for Rhombus-Chassis Electric Vehicles With Independent-Powered Wheels

2008 ◽  
Author(s):  
Cheng-Ho Li ◽  
Yu-Ying Peng ◽  
Tien-Ho Gau ◽  
James H. Wang ◽  
Chin-Pin Chien
Keyword(s):  
Control System ◽  
Electric Vehicles ◽  
Power Efficiency ◽  
Low Noise ◽  
Differential Relation ◽  
Straight Line ◽  
Constant Radius ◽  
Turning Center ◽  
Angular Velocities ◽  
Differential Control

Light electric vehicles (LEV) have been developed for the interests of green, low pollution and low noise. The development of in-wheel motors improve electric vehicles’ power efficiency and simplify the transmission system design. However, to coordinate the wheel torques and their angular velocities becomes an issue, which affects the vehicle’s dynamics and handling stability. In this paper, an electric differential system (EDS) for a rhombus-chassis EV is focused on. The relation of driving wheels’ speeds was derived particularly for rhombus configuration, and it has been carried out on a control system. Compared to the conventional control strategy for three-wheeled vehicles, the proposed method could estimate a more accurate turning center with sensing the tail wheel’s rotating angle that is beneficial to smoothen vehicle’s cornering with a more adequate differential relation. Experiments were carried out with a real concept car “ITRI LEV 1,” and tests such as straight-line test, constant-radius test, and Slalom turn test were conducted. The results show the EDS could effectively improve vehicle’s maneuverability and stability. The required steering angle became larger and trending to under steering while enabling the proposed EDS system, and wheel skidding was also effectively prevented in both constant-radius and Slalom turn tests.

Microdensitometer—computer correlation analysis of ultrastructural periodicity

1978 ◽  
Vol 36 (2) ◽  
pp. 32-33
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker
Keyword(s):  
Correlation Analysis ◽  
Background Noise ◽  
Computer Control ◽  
Optical Diffraction ◽  
Screw Thread ◽  
Straight Line ◽  
Computer Storage ◽  
Correlation Process ◽  
Electron Microscope Image ◽  
Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

1983 ◽  
Vol 41 ◽  
pp. 646-647
Author(s):  
Joseph A. Zasadzinski
Keyword(s):  
Liquid Crystalline ◽  
Freeze Fracture ◽  
Continuum Theory ◽  
Closed Surfaces ◽  
Straight Line ◽  
Low Weight ◽  
Concentric Spheres ◽  
Membrane Geometry ◽  
Dupin Cyclides ◽  
Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

Human Enamel Replication

1976 ◽  
Vol 34 ◽  
pp. 180-181
Author(s):  
Norman L. Dockum ◽  
John G. Dockum
Keyword(s):  
Organic Matrix ◽  
Human Teeth ◽  
Human Enamel ◽  
Straight Line ◽  
Ultrastructural Characteristics

Ultrastructural characteristics of fractured human enamel and acid-etched enamel were compared using acetate replicas shadowed with platinum and palladium. Shadowed replications of acid-etched surfaces were also obtained by the same method.Enamel from human teeth has a rod structure within which there are crystals of hydroxyapatite contained within a structureless organic matrix composed of keratin. The rods which run at right angles from the dentino-enamel junction are considered to run in a straight line perpendicular to the perimeter of the enamel, however, in many areas these enamel rods overlap, interlacing and intertwining with one another.

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