Abstract: Truck platooning refers to a convoy of digitally connected automated trucks traveling safely with a small inter-vehicle gap. It has been identified as one of the most promising and applicable technologies towards automated and sustainable freight transportation. Although truck platooning delivers significant energy-saving benefits, it cannot be realized without good coordination of drivers’ shifts to lead the platoons subject to their mandatory breaks. Therefore, this study aims to route a fleet of trucks to their destinations using the least amount of fuel by maximizing platoon opportunities under the regulations of drivers’ mandatory breaks. We formulate this platoon coordination problem as a mixed-integer linear programming problem and solve it by CPLEX. Numerical experiments are conducted to demonstrate the effectiveness and efficiency of our proposed model. In addition, we also explore the impacts of drivers’ compulsory breaks on the fuel-savings performance. The results show a slight increase in the total fuel costs in the presence of drivers’ compulsory breaks, thanks to driving-while-resting benefit provided for the trailing trucks. This study may serve as a guide for the operators of automated freight transportation.
Abstract: In this paper, a longitudinal and lateral control approach
based on a nonlinear observer is proposed for a convoy of autonomous
vehicles to follow a desired trajectory. To authors best knowledge,
this topic has not yet been sufficiently addressed in the literature
for the control of multi vehicles. The modeling of the convoy
of the vehicles is revisited using a robotic method for simulation
purposes and control design. With these models, a sliding mode
observer is proposed to estimate the states of each vehicle in the
convoy from the available sensors, then a sliding mode control
based on this observer is used to control the longitudinal and lateral
movement. The validation and performance evaluation are done using
the well-known driving simulator Scanner-Studio. The results are
presented for different maneuvers of 5 vehicles.
Abstract: The new emerging Visible Light Communication
(VLC) technology has been subjected to intensive investigation,
evaluation, and lately, deployed in the context of convoy-based
applications for Intelligent Transportations Systems (ITS). The
technology limitations were defined and supported by different
solutions proposals to enhance the crucial alignment and mobility
limitations. In this paper, we propose the incorporation of VLC
technology and Lane-Centering (LC) technique to assure the
VLC-connectivity by keeping the autonomous vehicle aligned to
the lane center using vision-based lane detection in a convoy-based
formation. Such combination can ensure the optical communication
connectivity with a lateral error less than 30 cm. As soon as the
road lanes are detectable, the evaluated system showed stable
behavior independently from the inter-vehicle distances and
without the need for any exchanged information of the remote
vehicles. The evaluation of the proposed system is verified using
VLC prototype and an empirical result of LC running application
over 60 km in Madrid M40 highway.
Abstract: An accurate procedure to determine free vibrations of
beams and plates is presented.
The natural frequencies are exact solutions of governing vibration
equations witch load to a nonlinear homogeny system.
The bilinear and linear structures considered simulate a bridge.
The dynamic behavior of this one is analyzed by using the theory of
the orthotropic plate simply supported on two sides and free on the
two others. The plate can be excited by a convoy of constant or
harmonic loads. The determination of the dynamic response of the
structures considered requires knowledge of the free frequencies and
the shape modes of vibrations. Our work is in this context. Indeed,
we are interested to develop a self-consistent calculation of the Eigen
frequencies.
The formulation is based on the determination of the solution of
the differential equations of vibrations. The boundary conditions
corresponding to the shape modes permit to lead to a homogeneous
system. Determination of the noncommonplace solutions of this
system led to a nonlinear problem in Eigen frequencies.
We thus, develop a computer code for the determination of the
eigenvalues. It is based on a method of bisection with interpolation
whose precision reaches 10 -12. Moreover, to determine the
corresponding modes, the calculation algorithm that we develop uses
the method of Gauss with a partial optimization of the "pivots"
combined with an inverse power procedure. The Eigen frequencies
of a plate simply supported along two opposite sides while
considering the two other free sides are thus analyzed. The results
could be generalized with the case of a beam by regarding it as a
plate with low width.
We give, in this paper, some examples of treated cases. The
comparison with results presented in the literature is completely
satisfactory.
Abstract: The evolution of technology and construction techniques has enabled the upgrading of transport networks. In particular, the high-speed rail networks allow convoys to peak at above 300 km/h. These structures, however, often significantly impact the surrounding environment. Among the effects of greater importance are the ones provoked by the soundwave connected to train transit. The wave propagation affects the quality of life in areas surrounding the tracks, often for several hundred metres. There are substantial damages to properties (buildings and land), in terms of market depreciation. The present study, integrating expertise in acoustics, computering and evaluation fields, outlines a useful model to select project paths so as to minimize the noise impact and reduce the causes of possible litigation. It also facilitates the rational selection of initiatives to contain the environmental damage to the already existing railway tracks. The research is developed with reference to the Italian regulatory framework (usually more stringent than European and international standards) and refers to a case study concerning the high speed network in Italy.