31 research outputs found
On distributed model predictive control for vehicle platooning with a recursive feasibility guarantee
Robust control of a clutch system to prevent judder-induced driveline oscillations
Oscillations in the driveline of a vehicle, specifically originating from the clutch system, are referred to as clutch judder. This paper presents the design of a robust controller to actively damp these judder-induced oscillations. A DK-iteration procedure, combining H8-controller synthesis and µ-analysis, is adopted for the robust controller design. The clutch judder model used is based on and validated with measurements on a heavy-duty vehicle powertrain. The feasibility of the control concept is evaluated by simulations and hardware-in-the-loop experiments
Towards on-the-road implementation of cooperative adaptive cruise control
This paper presents a setup for cooperative adaptive cruise control for which feasibility of the actual implementation is one of the main objectives. The approach considers communication with the directly preceding vehicle only, can deal with heterogeneous traffic, accounts for communication delay, and enables graceful degradation to standard adaptive cruise control if communication fails. The stability of a string of vehicles is analyzed using a frequency-domain approach
String-stable CACC design and experimental validation, a frequency-domain approach
The design of a Cooperative Adaptive Cruise Control (CACC) system and its practical validation are presented. The proposed CACC system includes a wireless communication link with the nearest preceding vehicle. The CACC design targets string-stable system behavior for a platoon of vehicles driving at small inter-vehicle distances. The string-stability characteristics of the system are assessed using a frequency-domain approach. Considering a velocity-dependent inter-vehicle spacing policy, it is shown that the communicated information enables small inter-vehicle distances, while maintaining string-stable behavior, whereas for a constant, velocity-independent inter-vehicle spacing, string stability can not be guaranteed. To validate the theoretical results, experiments are performed with two CACC-equipped vehicles
Predictive cruise control in hybrid electric vehicles
Deceleration rates have considerable influence on the fuel economy of hybrid electric vehicles. Given the vehicle characteristics and actual/measured operating conditions, as well as upcoming route information, optimal velocity trajectories can be constructed that maximize energy recovery. To support the driver in tracking of the energy optimal velocity trajectory, automatic cruise control is an important driver aid. In practice, perfect tracking of the optimal velocity trajectory is often not possible. An Adaptive Cruise Control (ACC) system is employed to react to the actual traffic situation. The combination of optimal velocity trajectory construction and ACC is presented as Predictive Cruise Control (PCC)
Predictive cruise control in hybrid electric vehicles
Deceleration rates have considerable influence on the fuel economy of hybrid electric vehicles. Given the vehicle characteristics and actual/measured operating conditions, as well as upcoming route information, optimal velocity trajectories can be constructed that maximize energy recovery. To support the driver in tracking of the energy optimal velocity trajectory, automatic cruise control is an important driver aid. In practice, perfect tracking of the optimal velocity trajectory is often not possible. An Adaptive Cruise Control (ACC) system is employed to react to the actual traffic situation. The combination of optimal velocity trajectory construction and ACC is presented as Predictive Cruise Control (PCC)
Cooperative adaptive cruise control, design and experiments
The design of a CACC system and corresponding experiments are presented. The design targets string stable system behavior, which is assessed using a frequency-domain-based approach. Following this approach, it is shown that the available wireless information enables small inter-vehicle distances, while maintaining string stable behavior. The theoretical results are validated by experiments with two CACC-equipped vehicles. Measurement results showing string stable as well as string unstable behavior are discussed