5 research outputs found
Penetration effect of connected and automated vehicles on cooperative on‐ramp merging
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166263/1/itr2bf00795.pd
Safety benefit of cooperative control for heterogeneous traffic on-ramp merging
The safety of heterogeneous traffic is a vital topic in the oncoming era of autonomous vehicles (AVs). The cooperative vehicle infrastructure system (CVIS) is considered to improve heterogeneous traffic safety by connecting and controlling AVs cooperatively, and the connected AVs are so-called connected and automated vehicles (CAVs). However, the safety impact of cooperative control strategy on the heterogeneous traffic with CAVs and human-driving vehicles (HVs) has not been well investigated. In this paper, based on the traffic simulator SUMO, we designed a typical highway scenario of on-ramp merging and adopted a cooperative control method for CAVs. We then compared the safety performance for two different heterogeneous traffic systems, i.e. AV and HV, CAV and HV, respectively, to illustrate the safety benefits of the cooperative control strategy. We found that the safety performance of the CAV and HV traffic system does not always outperform that of AV and HV. With random departSpeed and higher arrival rate, the proposed cooperative control method would decrease the conflicts significantly whereas the penetration rate is over 80%. We further investigated the conflicts in terms of the leading and following vehicle types, and found that the risk of a AV/CAV followed by a HV is twice that of a HV followed by another HV. We also considered the safety effect of communication failure, and found that there is no significant impact until the packet loss probability is greater than 30%, while communication delay\u27s impact on safety can be ignored according to our experiments
Robust Visual Imitation Learning with Inverse Dynamics Representations
Imitation learning (IL) has achieved considerable success in solving complex
sequential decision-making problems. However, current IL methods mainly assume
that the environment for learning policies is the same as the environment for
collecting expert datasets. Therefore, these methods may fail to work when
there are slight differences between the learning and expert environments,
especially for challenging problems with high-dimensional image observations.
However, in real-world scenarios, it is rare to have the chance to collect
expert trajectories precisely in the target learning environment. To address
this challenge, we propose a novel robust imitation learning approach, where we
develop an inverse dynamics state representation learning objective to align
the expert environment and the learning environment. With the abstract state
representation, we design an effective reward function, which thoroughly
measures the similarity between behavior data and expert data not only
element-wise, but also from the trajectory level. We conduct extensive
experiments to evaluate the proposed approach under various visual
perturbations and in diverse visual control tasks. Our approach can achieve a
near-expert performance in most environments, and significantly outperforms the
state-of-the-art visual IL methods and robust IL methods