Browse Topic: Cooperative driving automation
We present DISRUPT, a research project to develop a cooperative traffic perception and prediction system based on networked infrastructure and vehicle sensors. Decentralized tracking and prediction algorithms are used to estimate the dynamic state of road users and predict their state in the near future. Compared to centralized approaches, which currently dominate traffic perception, decentralized algorithms offer advantages such as greater flexibility, robustness and scalability. Mobile sensor boxes are used as infrastructure sensors and the locally calculated state estimates are communicated in such a way that they can augment local estimates from other sensor boxes and/or vehicles. In addition, the information is transferred to a cloud that collects the local estimates and provides traffic visualization functionalities. The prediction module then calculates the future dynamic state based on neurocognitive behavior models and a measure of a road user's risk of being involved in dangerous situations. Based on this measure, alerts are generated and transmitted to road users equipped with an accident prevention app. An important component of DISRUPT is the development of a digital twin for testing and optimizing the overall system and its individual components. The main feature of the digital twin is the simulation of a photorealistic virtual copy of the test field environment. This enables the simulation of radar, infrared and conventional visible light cameras, which are combined with simulated data transmission delays to replicate the real system as accurately as possible. The plug-and-play design of the digital twin, together with a toolset for running and analyzing numerous simulations, enables efficient and thorough testing of the tracking and prediction algorithms. In particular, the digital twin enables the generation of hazard scenarios that are very unlikely to be observed in everyday traffic.
This standard provides the guideline for enhancements to adaptive cruise control (ACC) by the addition of wireless communication from relevant vehicles (V2V) and/or the infrastructure (I2V) to augment the ACC active sensing capability. The CACC system operates under driver responsibility and supervision and is limited to the following: Does only longitudinal control of the vehicle. Uses time gap control strategy similar to ACC. Motor vehicles covered in the scope of this document include light and heavy vehicles. The message elements to realize CACC and platooning are part of the scope. The initial release covers definitions for CACC and platooning and requirements for CACC, while a subsequent release will cover the platooning requirements.
Presently, a main mobility sector objective is to reduce its impact on the global greenhouse gas emissions. While there are many techniques being explored, a promising approach to improve fuel economy is to reduce the required energy by using slipstream effects. This study analyzes the demanded engine power and mechanical energy used by heavy-duty trucks during platooning and non-platooning operation to determine the aerodynamic benefits of the slipstream. A series of platooning tests utilizing class 8 semi-trucks platooning via Cooperative Adaptive Cruise Control (CACC) are performed. Comparing the demanded engine power and mechanical energy used reveals the benefits of platooning on the aerodynamic drag while disregarding any potential negative side effects on the engine. However, energy savings were lower than expected in some cases. It was hypothesized that the CACC may have amplified transient platooning events relative to the individual truck baseline results, hampering the potential energy savings. Therefore, the impact of the controller on the observed driving style was analyzed in detail. In order to quantify the transient operational characteristics of the experimental trials, metrics from the European Real Driving Emissions (RDE) legislation were modified to serve as metrics of aggressiveness during platooning. The metrics (v ⋅ apos)95 and Relative Positive Acceleration (RPA) were calculated for platooning and non-platooning runs. These results indicate that the CACC induces small acceleration events during platooning to retain the commanded longitudinal separation between vehicles. These small acceleration events increase following vehicle aggressiveness during platooning and prevent the following vehicles from obtaining maximum energy savings. Moreover, a correlation between the RDE metric (v ⋅ apos)95 and energy savings is developed. Hence, this work establishes the ability of RDE metrics to assess CACC impacts on platoon energy savings.
A Cooperative Adaptive Cruise Control (CACC) platooning system was developed and implemented on Class 8 heavy duty trucks. The system allows for longitudinal, or gap spacing, control of the vehicle, while lateral control is maintained by the driver. Many previous aerodynamic studies have shown a reduction in drag force from vehicles traveling in close proximity to each other. This “drafting” effect leads to potential fuel savings for all vehicles in the platoon. Several automated driving and CACC systems have been tested in simulation or closed track settings to evaluate these fuel savings. However, there are only a few examples of potential fuel savings in real on-road or highway environments. This paper provides control performance, fuel economy, lateral offset, and number of neighboring vehicle results of an on-road platoon. The CACC system was implemented on two Peterbilt 579 commercial trucks with unloaded 53’ box trailers. Testing occurred on highways around Montreal, Quebec with a total platooned distance of approximately 1090 km. Gap distances varied over a range of 18.3-91.4 m (60-300 ft) with speeds of 89-105 km/h (55-65 mph). Fuel economy analysis was calculated from the SAE J1939 CAN bus data. Overall, the results show the feasibility and realizable benefits of CACC systems. Future validation of this CACC platooning system through SAE type II fuel tests is also discussed.
ABSTRACT The transportation industry annually travels more than 6 times as many miles as passenger vehicles [1]. The fuel cost associated with this represents 38% of the total marginal operating cost for this industry [8]. As a result, industry’s interest in applications of autonomy have grown. One application of this technology is Cooperative Adaptive Cruise Control (CACC) using Dedicated Short-Range Communications (DSRC). Auburn University outfitted four class 8 vehicles, two Peterbilt 579’s and two M915’s, with a basic hardware suite, and software library to enable level 1 autonomy. These algorithms were tested in controlled environments, such as the American Center for Mobility (ACM), and on public roads, such as highway 280 in Alabama, and Interstates 275/696 in Michigan. This paper reviews the results of these real-world tests and discusses the anomalies and failures that occurred during testing. Citation: Jacob Ward, Patrick Smith, Dan Pierce, David Bevly, Paul Richardson, Sridhar Lakshmanan, Athanasios Argyris, Brandon Smyth, Cristian Adam, Scott Heim “Cooperative Adaptive Cruise Control (CACC) in Controlled and Real-World Environments: Testing and Results”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019.
Items per page:
50
1 – 42 of 42