Adaptive Cruise Control of Vehicle Platoons with Wireless State Information
TL;DR: In this article, the authors proposed a real-time cooperative adaptive cruise controller (CACC) for highway platoons, which uses weighted and filtered accelerations of all preceding vehicles to guarantee the string stability of highway platoon.
About: This article is published in IFAC Proceedings Volumes.The article was published on 2013-01-01. It has received 3 citations till now. The article focuses on the topics: Platoon & Cruise control.
Citations
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01 Jan 2011
TL;DR: In this article, the authors use wireless inter-vehicle communications to provide real-time information of the preceding vehicle, in addition to the information obtained by common Adaptive Cruise Control (ACC) sensors, appears to significantly decrease the feasible time gap.
Abstract: Road throughput can be increased by driving at small inter-vehicle time gaps. The amplification of velocity disturbances in upstream direction, however, poses limitations to the minimum feasible time gap. This effect is covered by the notion of string stability. String-stable behavior is thus considered an essential requirement for the design of automatic distance control systems, which are needed to allow for safe driving at time gaps well below 1 s. Using wireless inter-vehicle communications to provide real-time information of the preceding vehicle, in addition to the information obtained by common Adaptive Cruise Control (ACC) sensors, appears to significantly decrease the feasible time gap, which is shown by practical experiments with a test fleet consisting of six passenger vehicles. The large-scale deployment of this system, known as Cooperative ACC (CACC), however, poses challenges with respect to the reliability of the wireless communication system. A solution for this scalability problem can be found in decreasing the transmission power and/or beaconing rate, or adapting the communications protocol. Although the main CACC objective is to increase road throughput, the first commercial application of CACC is foreseen to be in truck platooning, since short distance following is expected to yield significant fuel savings in this case.
5 citations
Dissertation•
14 May 2014
TL;DR: In this paper, a set of three dimensional motion coordination and formation control schemes for teams of autonomous vehicles is proposed, and a distributed control scheme to solve this problem utilizing the notions of graph rigidity and persistence as well as techniques of virtual target tracking and smooth switching.
Abstract: This thesis considers the cooperation and coordination of multi vehicle systems cohesively in order to keep the formation geometry and provide the string stability. We first present the modeling of aerial and road vehicles representing different motion characteristics suitable for cooperative operations. Then, a set of three dimensional cohesive motion coordination and formation control schemes for teams of autonomous vehicles is proposed. The two main components of these schemes are i) platform free high level online trajectory generation algorithms and ii) individual trajectory tracking controllers. High level algorithms generate the desired trajectories for three dimensional leader-follower structured tight formations, and then distributed controllers provide the individual control of each agent for tracking the desired trajectories. The generic goal of the control scheme is to move the agents while maintaining the formation geometry. We propose a distributed control scheme to solve this problem utilizing the notions of graph rigidity and persistence as well as techniques of virtual target tracking and smooth switching. The distributed control scheme is developed by modeling the agent kinematics as a single-velocity integrator; nevertheless, extension to the cases with simplified kinematic and dynamic models of fixed-wing autonomous aerial vehicles and quadrotors is discussed. The cohesive cooperation in three dimensions is so beneficial for surveillance and reconnaissance activities with optimal geometries, operation security in military activities, more viable with autonomous flying, and future aeronautics aspects, such as fractionated spacecraft and tethered formation flying. We then focus on motion control task modeling for three dimensional agent kinematics and considering parametric uncertainties originated from inertial measurement noise. We design an adaptive controller to perform the three dimensional motion control task, paying attention to the parametric uncertainties, and employing a recently developed immersion and invariance based scheme. Next, the cooperative driving of road vehicles in a platoon and string stability concepts in one-dimensional traffic are discussed. Collaborative driving of commercial vehicles has significant advantages while platooning on highways, including increased road-capacity and reduced traffic congestion in daily traffic. Several companies in the automotive sector have started implementing driver assistance systems and adaptive cruise control (ACC) support, which enables implementation of high level cooperative algorithms with additional softwares and simple electronic modifications. In this context, the cooperative adaptive cruise control approach are discussed for specific urban and highway platooning missions. In addition, we provide details of vehicle parameters, mathematical models of control structures, and experimental tests for the validation of our models. Moreover, the impact of vehicle to vehicle communication in the existence of static road-side units are given. Finally, we propose a set of stability guaranteed controllers for highway platooning missions. Formal problem definition of highway platooning considering constant and velocity dependent spacing strategies, and formal string stability analysis are included. Additionally, we provide the design of novel intervehicle distance based priority coefficient of feed-forward
3 citations
Cites background from "Adaptive Cruise Control of Vehicle ..."
...Velocity dependent intervehicle spacing, • A novel design of intervehicle spacing based priority filter for wireless state information from preceding vehicles in order to mitigate higher time delay factors [9]....
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01 Oct 2019
TL;DR: Simulation results demonstrate that the ego vehicle can reasonable response the accelerating or decelerating behaviors of the preceding vehicles under the proposed controller, thereby the desired CACC control performance is satisfied, and the wireless communication delay and actuator delay are compensated effectively.
Abstract: The centralized longitudinal control problem for Cooperative Adaptive Cruise Control (CACC) systems is discussed in this paper, in which the imperfect wireless communication surroundings and actuator dynamics are taken into consideration. From the large-scale system standpoint, the centralized longitudinal control problem for platoon vehicles equipped with CACC functionality is formulated as minimizing a quadratic performance index under the constrains of a large-scale discrete-time system with actuator delay and system output delay, in which the leader vehicle is set as the control center. After that, benefiting from a designed delay-free transformed vector, a delay-free two-point-boundary-value problem is derived from the equivalent reconstruction forms for original system delay model and performance index. Thus the centralized longitudinal controller is obtained by solving a Riccati equation. Finally, simulation results demonstrate that the ego vehicle can reasonable response the accelerating or decelerating behaviors of the preceding vehicles under the proposed controller, thereby the desired CACC control performance is satisfied, and the wireless communication delay and actuator delay are compensated effectively.
1 citations
Cites background from "Adaptive Cruise Control of Vehicle ..."
...Based on [14], the longitudinal dynamic parameters for different platoon vehicles are listed in Table 1....
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References
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TL;DR: Implementation of the CACC system, the string-stability characteristics of the practical setup, and experimental results are discussed, indicating the advantages of the design over standard adaptive-cruise-control functionality.
Abstract: The design of a cooperative adaptive cruise-control (CACC) system and its practical validation are presented. Focusing on the feasibility of implementation, a decentralized controller design with a limited communication structure is proposed (in this case, a wireless communication link with the nearest preceding vehicle only). A necessary and sufficient frequency-domain condition for string stability is derived, taking into account heterogeneous traffic, i.e., vehicles with possibly different characteristics. For a velocity-dependent intervehicle spacing policy, it is shown that the wireless communication link enables driving at small intervehicle distances, whereas string stability is guaranteed. For a constant velocity-independent intervehicle spacing, string stability cannot be guaranteed. To validate the theoretical results, experiments are performed with two CACC-equipped vehicles. Implementation of the CACC system, the string-stability characteristics of the practical setup, and experimental results are discussed, indicating the advantages of the design over standard adaptive-cruise-control functionality.
779 citations
TL;DR: Using wireless inter-vehicle communications to provide real-time information of the preceding vehicle, in addition to the information obtained by common Adaptive Cruise Control sensors, appears to significantly decrease the feasible time gap, which is shown by practical experiments with a test fleet consisting of six passenger vehicles.
Abstract: Road throughput can be increased by driving at small inter-vehicle time gaps. The amplification of velocity disturbances in upstream direction, however, poses limitations to the minimum feasible time gap. This effect is covered by the notion of string stability. String-stable behavior is thus considered an essential requirement for the design of automatic distance control systems, which are needed to allow for safe driving at time gaps well below 1 s. Using wireless inter-vehicle communications to provide real-time information of the preceding vehicle, in addition to the information obtained by common Adaptive Cruise Control (ACC) sensors, appears to significantly decrease the feasible time gap, which is shown by practical experiments with a test fleet consisting of six passenger vehicles. The large-scale deployment of this system, known as Cooperative ACC (CACC), however, poses challenges with respect to the reliability of the wireless communication system. A solution for this scalability problem can be found in decreasing the transmission power and/or beaconing rate, or adapting the communications protocol. Although the main CACC objective is to increase road throughput, the first commercial application of CACC is foreseen to be in truck platooning, since short distance following is expected to yield significant fuel savings in this case.
136 citations
03 Mar 2011
TL;DR: In this paper, the traffic efficiency of an advisory cooperative driving system, Advisory Acceleration Control, is examined and compared to the efficiency of autonomous cooperative driving systems, Cooperative Adaptive Cruise Control.
Abstract: In this paper, the traffic efficiency of an advisory cooperative driving system, Advisory Acceleration Control is examined and compared to the efficiency of an autonomous cooperative driving system, Cooperative Adaptive Cruise Control. The algorithms and implementation thereof are explained. The results of both systems are presented and discussed1.
26 citations
01 Oct 2012
TL;DR: The hardware design and the low level control strategy for braking, throttle and gearshift actuators for these case studies for a Grand Cooperative Driving Challenge (GCDC) program the authors involved in are presented.
Abstract: In this paper, we focus on cooperative adaptive cruise control of ground vehicles and platoon stability in daily traffic. The general adaptive cruise control (ACC) structure and different cooperative adaptive cruise control (CACC) approaches are discussed for highway platooning, considering case studies for a Grand Cooperative Driving Challenge (GCDC) program the authors involved in. The hardware design and the low level control strategy for braking, throttle and gearshift actuators for these case studies are presented. Finally, the performance of a PD based CACC algorithm used in GCDC is analyzed.
11 citations