Youla-Kucera Based Lateral Controller for Autonomous Vehicle

International audienceThis paper presents the design and implementation of a novel lateral control approach. The proposed control strategy is based on Youla-Kucera parametrization to switch gradually between controllers that are designed separately for big and small lateral errors. The present approach studies the critical problem of initial lateral error in line following. It ensures smooth and stable transitions between controllers and provides a smooth vehicle response regardless of the lateral error. For an initial validation the present work was tested in simulation, implementing a dynamic bicycle model. It has also been tested in real platforms implementing an electric Renault ZOE, with good results when activating the system at different lateral errors. autonomous vehicles Switched controllers parametrization

Learning over All Stabilizing Nonlinear Controllers for a Partially-Observed Linear System

This paper proposes a nonlinear policy architecture for control of partially-observed linear dynamical systems providing built-in closed-loop stability guarantees. The policy is based on a nonlinear version of the Youla parameterization, and augments a known stabilizing linear controller with a nonlinear operator from a recently developed class of dynamic neural network models called the recurrent equilibrium network (REN). We prove that RENs are universal approximators of contracting and Lipschitz nonlinear systems, and subsequently show that the the proposed Youla-REN architecture is a universal approximator of stabilizing nonlinear controllers. The REN architecture simplifies learning since unconstrained optimization can be applied, and we consider both a model-based case where exact gradients are available and reinforcement learning using random search with zeroth-order oracles. In simulation examples our method converges faster to better controllers and is more scalable than existing methods, while guaranteeing stability during learning transients

A first approach for a passenger-centered behavior on driverless vehicles

International audienceDriverless shuttles are becoming one of the most promising applications of automated vehicle technologies in the short term. For a real system deployment, passenger's acceptance on the shuttle performance will play a key role. This paper presents a passenger-centered control algorithm design for increasing passenger's ride quality. Controllers with different performance but properly following the reference are developed for lane-level autonomous navigation. The whole solution has been implemented and tested in a real vehicle, using a roundabout as use-case scenario, providing encouraging results

Advances in Youla-Kucera parametrization: A Review

International audienceYoula-Kucera (YK) parametrization was formulated decades ago for obtaining the set of controllers stabilizing a linear plant. This fundamental result of control theory has been used to develop theoretical tools solving many control problems ranging from stable controller switching, closed-loop identification, robust control, disturbance rejection, adaptive control to fault tolerant control.This paper collects the recent work and classifies the maccording to the use of YK parametrization, Dual YK parametrization or both, providing the latest advances with main applications indifferent control fields. A final discussion gives some insights on the future trends in the field