Gjl Gerrit Naus

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. 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.

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 ℋ∞-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.

Explicit MPC design and performance-based tuning of an Adaptive Cruise Control Stop-&-Go

This paper presents the synthesis, the implementation and the performance-based tuning of an adaptive cruise control (ACC) stop-&-go (S&G) design. A model predictive control (MPC) framework is adopted to design the controller. Performance of the controller is evaluated, distinguishing between comfort of the resulting longitudinal vehicle behavior and the behavior due to traffic requirements. Corresponding metrics are incorporated in the controller design. Performance functions, relating the metrics explicitly to comfort and traffic requirements enable tuning of the resulting controller. As a result, the performance of the controller can be changed by a single performance-based weight. Simulation results for varying controller performance in various traffic situations are shown.

A model predictive control approach to design a parameterized adaptive cruise control

The combination of different desirable characteristics and situation-dependent behavior cause the design of adaptive cruise control (ACC) systems to be time consuming and tedious. This chapter presents a systematic approach for the design and tuning of an ACC, based on model predictive control (MPC). A unique feature of the synthesized ACC is its parameterization in terms of the key characteristics safety, comfort and fuel economy. This makes it easy and intuitive to tune, even for nonexperts in (MPC) control, such as the driver. The effectiveness of the design approach is demonstrated using simulations for some relevant traffic scenarios.

Modeling and Control of a DC Upset Resistance Butt Welding Process

This paper presents the analysis and synthesis of modeling and control of the DC upset resistance butt welding process used in rim production lines. A new control strategy is developed, enabling active control of the welding seam temperature and the upset size. As a result, set-up times and energy consumption are reduced significantly.