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In this paper, we present a new car-following model, i.e. comprehensive optimal velocity model (COVM), whose optimal velocity function not only depends on the following distance of the preceding vehicle, but also depends on the velocity difference with preceding vehicle. Simulation results show that COVM is an improvement over the previous ones theoretically. Then, the stability condition of the model is obtained by the linear stability analysis, which has shown that the model could obtain a bigger stable region thanprevious models in the phase diagram. Through the nonlinear analysis, the Burgers, Korteweg-de Vries (KdV) and modified KdV (mKdV) equations are derived for the triangular shock wave, the soliton wave, and the kink-antikink soliton wave. At the same time, numerical simulations are also carried out to show that the model could simulate these density waves. 相似文献
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在考虑行人视野范围的随机偏走格子气模型基础上, 引入行人对前方开阔区域的移动偏好特性, 提出改进的格子气模型, 对通道内对向行人流进行仿真研究. 模型再现了对向行人流在不同密度下出现的3种演化过程, 发现了行人密度与对向行人流分层现象的形成具有随机性, 以及统计了概率的变化趋势, 同时分析了分层现象形成概率与系统几何尺寸参数、移动强度参数、右行人流比例参数和视野范围参数等的关系. 分析结果表明, 改进的模型能够再现实际低密度下对向行人流不会出现分层现象的特性. 根据分层形成的概率, 可将对向行人流的密度分为5个区间, 不同区间的行人流演化过程各有差异. 模型和分析结果对理解对向行人流的动态演化过程, 提高通道内对向行人流的走行效率有一定帮助. 相似文献
3.
The full velocity difference model proposed by Jiang et
al. [2001 Phys. Rev. E 64 017101] has been improved
by introducing velocity anticipation. Velocity anticipation means
the follower estimates the future velocity of the leader. The
stability condition of the new model is obtained by using the linear
stability theory. Theoretical results show that the stability region
increases when we increase the anticipation time interval. The mKdV
equation is derived to describe the kink--antikink soliton wave and
obtain the coexisting stability line. The delay time of car motion
and kinematic wave speed at jam density are obtained in this model.
Numerical simulations exhibit that when we increase the anticipation
time interval enough, the new model could avoid accidents under
urgent braking cases. Also, the traffic jam could be suppressed by
considering the anticipation velocity. All results demonstrate that
this model is an improvement on the full velocity difference model. 相似文献
4.
By introducing a flow difference effect, a modified lattice two-lane traffic flow model is proposed, which is proved to be capable of improving the stability of traffic flow. Both the linear stability condition and the kink-antikink solution derived from the modified Korteweg-de Vries (mKdV) equation are analyzed. Numerical simulations verify the theoretical analysis. Furthermore, the evolution laws under different disturbances in the metastable region are studied. 相似文献
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In this paper, a new lattice hydrodynamic model based on
Nagatani's model [Nagatani T 1998 Physica A 261 599] is
presented by introducing the flow difference effect. The stability
condition for the new model is obtained by using the linear
stability theory. The result shows that considering the flow
difference effect leads to stabilization of the system compared
with the original lattice hydrodynamic model. The jamming
transitions among the freely moving phase, the coexisting phase, and
the uniform congested phase are studied by nonlinear analysis.
The modified KdV equation near the critical point is derived to
describe the traffic jam, and kink--antikink soliton solutions
related to the traffic density waves are obtained. The simulation
results are consistent with the theoretical analysis for the new
model. 相似文献
6.
Huaqing Liu 《中国物理 B》2023,32(1):14501-014501
This paper investigates traffic flow of connected and automated vehicles at lane drop on two-lane highway. We evaluate and compare performance of an optimization-based control algorithm (OCA) with that of a heuristic rules-based algorithm (HRA). In the OCA, the average speed of each vehicle is maximized. In the HRA, virtual vehicle and restriction of the command acceleration caused by the virtual vehicle are introduced. It is found that (i) capacity under the HRA (denoted as CH) is smaller than capacity under the OCA; (ii) the travel delay is always smaller under the OCA, but driving is always much more comfortable under the HRA; (iii) when the inflow rate is smaller than CH, the HRA outperforms the OCA with respect to the fuel consumption and the monetary cost; (iv) when the inflow rate is larger than CH, the HRA initially performs better with respect to the fuel consumption and the monetary cost, but the OCA would become better after certain time. The spatiotemporal pattern and speed profile of traffic flow are presented, which explains the reason underlying the different performance. The study is expected to help for better understanding of the two different types of algorithm. 相似文献
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