Equalization of intervehicular distances in platoons on a circular track

Author(s):  
Ivo Herman ◽  
Dan Martinec ◽  
Zdenek Hurak ◽  
Michael Sebek
Keyword(s):  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Pierre-Yves Jacob ◽  
Fabrizio Capitano ◽  
Bruno Poucet ◽  
Etienne Save ◽  
Francesca Sargolini

Author(s):  
G Virzì Mariotti ◽  
G Ficarra

The research reported in this paper aims to simulate the road-holding of a virtual vehicle using multi-body simulation to estimate both the contact forces between the tyre and ground and the roll motion when cornering. Furthermore, the effect of the characteristic angles on the variation in the forces of the tyre in contact with the ground is studied to determine optimal values for these angles. Emphasis is placed on an average-class vehicle, of which both the external dimensions and mass are chosen appropriately, with a McPherson suspension mounted on both the front and the rear. The characteristic values of the camber and toe-in angles, in both the front and the rear, are optimized for motion in the curve under constant traction. The results of numerical simulation are compared with results from the theory of stability in the curve (given the vertical configuration of the vehicle).


Author(s):  
B. Balachandran ◽  
Y.-Y. Li

Abstract In this article, preliminary results obtained in the exploration of a mechanical filter concept for suppressing crane-load oscillations on a ship vessel are presented. The pivot point about which the load oscillates is constrained to follow a circular track in the considered filter. The governing dynamical systems for the cases with and without the filter are presented, and the nonlinear dynamics of these systems is studied with respect to quasi-static variation of different scalar control parameters. It is shown that the presence of the filter helps in eliminating some of the sub-critical bifurcations that may arise in the crane-load response during periodic ship-roll excitations.


2012 ◽  
Vol 9 (2) ◽  
pp. 163-167 ◽  
Author(s):  
G. S. Berezin ◽  
I. V. Boguslavskii ◽  
N. Grigalashvili ◽  
V. I. Davkov ◽  
K. I. Davkov ◽  
...  

Author(s):  
Aya Watanabe ◽  
Ryousuke Yuyama ◽  
Hiroshi Hosaka ◽  
Akira Yamashita

Abstract This paper describes a friction-driven gyro generator that works under arbitrary vibrations and generates more than 1 W of power. Vibrational generators are energy harvesters that convert environmental vibrations into electrical power via the inertial force of pendulums. In conventional generators that use simple vibration, the power is less than 10 mW for a wearable size because vibrations in the natural environment are as low as 1 Hz. Gyroscopic generators increase the inertial force by rotating a pendulum at high speed and creating a gyro effect. In this generator, a palm-size product that generates 0.1 W and weighs 280 g has already been commercialized, but this device operates only under a particular vibration that synchronizes rotor precession and stalls under random vibration. To solve this problem, in this research, two gimbals and a precession spring are introduced to support the rotor. We developed a prototype generator with straight tracks measuring 16 cm × 11 cm × 12 cm with a mass of 980 g. Under a vibration of 4 Hz and ±20 degrees, power generation of 1.6 W was confirmed. Next, a prototype circular track was made. Power generation of 0.2 W with a vibration of 1 Hz and ±90 degrees was confirmed. Finally, a simple formula to estimate the upper limit of the generation power is derived. It is suggested that the circular-type generator is suitable for low-frequency vibration and can generate twice the power of a straight-type generator.


Author(s):  
Satyavati Komaragiri ◽  
Armen Amirkhanian ◽  
Amit Bhasin

In the late 1980s and early 1990s, the Alabama Department of Transportation (ALDOT), U.S., noticed a decline in skid trailer numbers on concrete pavements shortly after grinding operations. The engineers at the time suspected that the coarse aggregate caused the decline in these numbers and the resulting conclusion led to a ban of carbonate aggregates in mainline concrete pavement in Alabama that is still in place. This detailed laboratory study re-examines the fundamental friction issues that led to this policy. A total of 48 aggregate, grinding, and grooving combinations were tested as part of this study. Three aggregate sources were examined: a siliceous source, a “hard” limestone source, and a “soft” limestone source. Two blade spacings were examined for grinding operations: 52 blades/ft and 60 blades/ft. Some ground specimens were also grooved. Finally, a set of specimens had the Next Generation Concrete Surface (NGCS) applied to them. The specimens were polished with the National Center for Asphalt Technology (NCAT) three-wheel polishing device (TWPD). The dynamic friction tester was used to evaluate friction values at various points through the polishing process. After the polishing, the macrotexture was characterized using the circular track meter. Across the board, the highest performing texture was that with no grooves and 52 blades/ft. Very generally, the loss of friction decreased with increasing siliceous content. However, some of the trends were extremely minor and, in a few cases, siliceous aggregates caused higher friction loss. There were numerous instances when blended carbonate/siliceous concrete pavement surfaces performed better than sole siliceous concrete pavement surfaces.


Sign in / Sign up

Export Citation Format

Share Document