Operational Concepts for Truck Maneuvers with Cooperative Adaptive Cruise Control

Abstract

Cooperative adaptive cruise control (CACC) has been loosely defined in recent literature to represent a wide variety of vehicle-following control concepts, and when trucks are discussed, CACC is often used synonymously with platooning. This paper discusses the similarities and differences between CACC and platooning and provides a more precise functional description of CACC operations for trucks. CACC operations include not only the steady state cruising mode but also the maneuvers needed to join vehicles together and separate them when a vehicle needs to leave a CACC string or when the string is interrupted by a cut-in maneuver by a noncooperative vehicle. Activity diagrams are used to describe the CACC maneuvers; the diagrams specify the sequence of actions that need to be taken by each driver and each vehicle (and its CACC software) and the information that needs to be exchanged between them. These precise definitions can be used to specify the vehicle-to-vehicle messages that need to be exchanged between vehicles to implement CACC and the driver–vehicle interface displays and controls that are needed. The paper also addresses practical considerations in CACC operation, such as maximum lengths for strings of CACC trucks, strategies for sequencing the trucks in CACC strings, and higher-level strategies for clustering CACC-capable trucks; these strategies range from ad hoc to local and global coordination.

A Survey on Cooperative Longitudinal Motion Control of Multiple Connected and Automated Vehicles

“…In the U.S., the PATH Program has developed three generations of proof-of-concept prototype truck platooning systems, including the first two based on Freightliner Century model tractors, and the third based on Volvo tractors [46]. Different cooperative operational concepts were developed and tested, including string formation, steady-state cruising, string split maneuvers, and managing faults or abnormal operating conditions [47]. Peloton Technology has focused on two-truck platooning product development since the company's founding in 2011, where its system has reported a 4.5% energy savings for the lead truck and 10% for the following truck [48].…”

Vehicle platooning with constant spacing strategies and multiple vehicle look ahead information

“…A spacing policy specifies the desired following distance and a controller is employed to regulate the spacing distance based on the information from other vehicles. In AHS, the controller in each vehicle maintains the spacing distance with its immediate predecessor by utilising: (i) on‐board sensory information such as its following distance, speed, relative speed with respect to its immediate predecessor or (ii) vehicle to vehicle or (iii) infrastructure to vehicle communication [1].…”

A hierarchical approach for splitting truck platoons near network discontinuities

“…Truck platooning is expected to be deployed earlier than passenger cars due to the pronounced benefits in terms of fuel saving [1] and promising business models [4,17]. Several on-road pilots have identified problems that truck platooning brings to traffic at freeway entrances and exits [4,17,25], which is of paramount importance to traffic safety and maximization of throughput in the traffic network. Therefore, coordination and control at network discontinuities are important challenges for vehicle platooning in real world.…”