Hao Yang,
Wen-Long Jin



Highlights

•Present a feedback control system with green driving strategies.
•Analyze a constant independent and three simple cooperative strategies.
•Propose three rules for effective and robust strategies.
•Develop a distributed cooperative strategy based on inter-vehicle communications.
•Illustrate environmental benefits for different market penetration rates.



Keywords
Distributed cooperative green driving; Advisory speed limit; Inter-vehicle communication; Market penetration rate; Communication delay



Abstract
Various green driving strategies have been proposed to smooth traffic flow and lower pollutant emissions and fuel consumption in stop-and-go traffic. In this paper, we present a control theoretic formulation of distributed, cooperative green driving strategies based on inter-vehicle communications (IVCs). The control variable is the advisory speed limit, which is designed to smooth a following vehicle’s speed profile without changing its average speed. We theoretically analyze the performance of a constant independent and three simple cooperative green driving strategies and present three rules for effective and robust strategies. We then develop a distributed cooperative green driving strategy, in which the advisory speed limit is first independently calculated by each individual vehicle and then averaged among green driving vehicles through IVC. By simulations with Newell’s car-following model and the Comprehensive Modal Emissions Model (CMEM), we demonstrate that such a strategy is effective and robust independently as well as cooperatively for different market penetration rates of IVC-equipped vehicles and communication delays. In particular, even when 5% of the vehicles implement the green driving strategy and the IVC communication delay is 60 s, the fuel consumption can be reduced by up to 15%. Finally we discuss some future extensions.



Article Outline
1. Introduction
2. Control system description
2.1. Newell’s car-following model
2.2. Emission model
2.3. Feedback control system

3. Simple green driving strategies
3.1. A constant independent green driving strategy
3.2. Three simple cooperative green driving strategies

4. A distributed cooperative green driving strategy
4.1. Calculation of the advisory speed limit
4.2. Smoothing effect of the independent strategy
4.3. Smoothing effects of the cooperative strategy with different market penetration rates and communication delays

5. Conclusion and future work
Acknowledgments
References



Figures
   

Fig. 1.

The following vehicle’s speed profile under different advisory speed limits.


Fig. 2.

Average and standard deviation of controlled speed with different  values (T = 200 s, ).


Fig. 3.

Feedback control system of a dynamic green driving strategy.


Fig. 4.

Average and standard deviation of the follower’s speed under different  values.


Fig. 5.

Comparison of speed profiles before and after green driving under congested traffic.


Fig. 6.

Comparison of speed profiles before and after green driving under less congested traffic.


Fig. 7.

Impact of MPR of green driving vehicles: (a) standard deviation of speed and (b) emissions and fuel consumption savings.


Fig. 8.

Impacts of communication delays: (a) standard deviation of speed and (b) emissions and fuel consumption savings.



Tables

Table 1. Setting of simulation and green driving strategy.

Table 2. Statistics of speed profiles before and after green driving under congested traffic.

Table 3. Emissions and fuel consumption before and after green driving under congested traffic.

Table 4. Statistics of speed profiles before and after green driving under less congested traffic.

Table 5. Emissions and fuel consumption before and after green driving under less congested traffic.