Vehicle Dynamics and Performance

2012 ◽  
pp. 67-90
Author(s):  
Yimin Gao
Author(s):  
V. V. Vantsevich

Wheel dynamics is a significant component of vehicle dynamics and performance analysis. This paper presents an innovative method of studying wheel dynamics and wheel performance control based on the inverse dynamics formulation of the problem. Such an approach opens up a new way to the optimization and control of both vehicle dynamics and vehicle performance by optimizing and controlling power distribution to the drive wheels. An equation of motion of a wheel is derived first from the wheel power balance equation that makes the equation more general. This equation of motion is considered the basis for studying both direct and inverse wheel dynamics. The development of a control strategy on the basis of the inverse wheel dynamics approach includes wheel torque control that provides a wheel with both the referred angular velocity and rolling radius and also with the required functionals of quality. An algorithm for controlling the angular velocity is presented as the first part in the implementation of the developed strategy of the inverse wheel dynamics/performance control.


1982 ◽  
Author(s):  
Campbell Duncan Carter ◽  
Cindy Barr Sherman ◽  
Ronald D. Matthews

Author(s):  
Joseph G. Guercio ◽  
Robert L. Wall

The importance of congruent and spurious yaw motion in compensatory tracking by eight airline pilots was examined. The pilots, seated erect in the Ames Man-Carrying Rotation Device (MCRD), tracked with k/s+1 and k/s(s+1) vehicle dynamics in fixed- and moving-base simulation. Following the learning phase of the experiment, five levels of spurious angular acceleration were superimposed on the motion of the MCRD. Learning of the tracking task was found to be a function of both vehicle dynamics and mode of simulation. The presence of congruent motion information reduced learning time in k/s(s+1) vehicle dynamics and resulted in lower tracking error in both vehicle dynamics. The spurious angular accelerations resulted in an increase in pilot tracking error; however, the relationship between the magnitude of the acceleration and its effect was highly complex. The data suggest that the minimal disturbance level for spurious angular accelerations during tracking is below 0.4°/sec.2.


Author(s):  
H. M. Thieringer

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.


Author(s):  
Huang Min ◽  
P.S. Flora ◽  
C.J. Harland ◽  
J.A. Venables

A cylindrical mirror analyser (CMA) has been built with a parallel recording detection system. It is being used for angular resolved electron spectroscopy (ARES) within a SEM. The CMA has been optimised for imaging applications; the inner cylinder contains a magnetically focused and scanned, 30kV, SEM electron-optical column. The CMA has a large inner radius (50.8mm) and a large collection solid angle (Ω > 1sterad). An energy resolution (ΔE/E) of 1-2% has been achieved. The design and performance of the combination SEM/CMA instrument has been described previously and the CMA and detector system has been used for low voltage electron spectroscopy. Here we discuss the use of the CMA for ARES and present some preliminary results.The CMA has been designed for an axis-to-ring focus and uses an annular type detector. This detector consists of a channel-plate/YAG/mirror assembly which is optically coupled to either a photomultiplier for spectroscopy or a TV camera for parallel detection.


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