Nicoleta Minoiu-Enache

Automatic Parallel Parking in Tiny Spots: Path Planning and Control

This paper presents automatic parallel parking for a passenger vehicle, with highlights on a path-planning method and on experimental results. The path-planning method consists of two parts. First, the kinematic model of the vehicle, with corresponding geometry, is used to create a path to park the vehicle in one or more maneuvers if the spot is very narrow. This path is constituted of circle arcs. Second, this path is transformed into a continuous-curvature path using clothoid curves. To execute the generated path, control inputs for steering angle and longitudinal velocity depending on the traveled distance are generated. Therefore, the traveled distance and the vehicle pose during a parking maneuver are estimated. Finally, the parking performance is tested on a prototype vehicle.

Geometric Path Planning for Automatic Parallel Parking in Tiny Spots

This paper deals with path planning for car-like vehicle in parallel parking problems. Our path planning method uses simple geometry of the vehicle kinematic model. The presented strategy consists in retrieving the vehicle from the parking spot and reversing the obtained path to park the vehicle. Two methods for parking in tiny spaces, where parking in one trial is not possible, are proposed. In these cases, the number of needed trials to park the vehicle can be calculated from a simple formula or from an iterative algorithm. The proposed planning methods are independent of the initial position and the orientation of the vehicle. Reference trajectories are generated so that the vehicle can park by following them. Simulations are provided for both methods.

A formal framework for the safe design of the Autonomous Driving supervision

The autonomous vehicle is meant to drive by itself, without any driver intervention (for the levels 4 and 5 of automated driving, according to the National Highway Traffic Safety Administration(NHTSA)). This car includes a new function, called Autonomous Driving (AD) function, in charge of driving the vehicle when it is authorized. This function may be in different states (basically active or inactive), that shall be managed by a sub-function, named supervision. The main focus of this work is to ensure that the supervision of a function, performed by a safety critical embedded automotive control system (controlled systems are not considered), respects functional and safety requirements. Usually two processes are involved in the system design: the systems engineering process and the safety one. The first process defines the functional requirements on the function while the safety one specifies redundant sub-functions (realizing together the function) allowing to ensure a continuous service under failure. Since two different aspects of the system are specified, it is a major challenge to make all requirements consistent, from the outset of the design process. In this paper, a method is precisely proposed to address this issue. A progressive reinforcement of the treated requirements is achieved by means of formal state models. In fact, the proposed approach permits to build state models from requirements initially expressed in natural language. Potential ambiguities, incompletenesses or undertones in requirements are in this way gradually deleted. The enrichment of conventional formal verification of control properties with safety requirements constitutes the main originality of the deployed method and contributes to solve inconsistencies between functional and safety verification processes. In addition, the application of the method to the design of AD function supervision highlights its efficiency in an industrial context.

Vehicle Yaw Motion Control Using Takagi-Sugeno Modeling and Quadratic Boundedness via Dynamic Output Feedback

This paper presents the design and the simulation test of a Takagi-Sugeno (TS) fuzzy output feedback for yaw motion control. An integrated steering and differential braking controller based on invariant sets, quadratic boundedness theory and a common Lyapunov function has been developed. The TS fuzzy model is able to handle elegantly the nonlinear behavior the vehicle lateral dynamics. The computation of the control law has been achieved using Linear and Bilinear Matrix Inequalities (LMI-BMI) methods. Simulation test shows the controlled car is able to achieve the ISO3888-2 transient maneuver. Some design parameters can be adjusted to handle the tradeoff between safety constraints and comfort specifications.Copyright