Method for controlling the path of an autonomous vehicle having steered wheels

• US 9,535,422 B2
• Filed: 07/01/2013
• Issued: 01/03/2017
• Est. Priority Date: 07/12/2012
• Status: Active Grant

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Minoiu-Enache, Nicoleta
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): McPherson, James M
• Application Number:
  US14/413,027
• Publication Number:
  US 20150185734A1
• Time in Patent Office: 1,282 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G01C 21/3415 Dynamic re-routing, e.g. recalculating the route when the user deviates from calculated route or after detecting real-time traffic data or accidents
• CPC Class Codes: G05D 1/0223 involving speed control of the vehicle vehicle fittings for automatically controlling, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator B60K31/00

Abstract

A method for controlling the position and speed of a vehicle having steered wheels includes, determining an overall path comprising a plurality of points and defining the course of the vehicle between a starting point and an endpoint; determining the current position of the vehicle; if the current position does not correspond to a point on the overall path, generating a local path connecting the current position of the vehicle to a point on the overall path; and generating control signals in order to steer the steered wheels and control the speed of the vehicle so that the vehicle moves along the local path. The control signals are generated by convex optimization of linear matrix inequalities.

Claims

1. A method for controlling a position and speed of a vehicle capable of moving in an autonomous manner and having at least one steered wheel, said method comprising:

determining an overall path defining a course of the vehicle between a starting point and an endpoint, said overall path having a plurality of intermediate points between the starting point and the endpoint;

defining a position being defined for each point of the overall path;

determining a current position of the vehicle;

generating, if the current position does not correspond to a point on the overall path, a local path connecting the current position of the vehicle to a point on the overall path, said local path having a plurality of points, a position and a speed defined for each point of the local path;

controlling, via a steering control signal generated via circuitry, the steered wheel of the vehicle and controlling, via a speed control signal generated via the circuitry, the speed of the vehicle so that the vehicle moves along said local path,

wherein the steering and speed control signals are generated by convex optimization of linear matrix inequalities.

2. The method as claimed in claim 1, wherein the generation of the steering control signal and of the speed control signal includes:

determining a kinematic model for the vehicle; and

determining the steering and speed control signals on the basis of said kinematic model by convex optimization of linear matrix inequalities.

3. The method as claimed in claim 2, wherein the kinematic model of the vehicle is determined on the basis of a kinematic model of a robot having two independent wheels, the kinematic model of the robot being supplemented by a plurality of constraints specific to vehicles having steered wheels.

4. The method as claimed in claim 3, wherein the plurality of constraints specific to vehicles having steered wheels includes:

a stability constraint which is asymptotic with respect to the local path,

a constraint of limitation of curvature of the local path,

a constraint of continuity and derivability of the steering and speed control signals, and

a constraint for feasibility of transposing the kinematic model from the robot having two independent wheels to a vehicle having at least one steered wheel.

5. The method as claimed in claim 4, wherein the kinematic model is supplemented with one or more constraints from among the following:

a constraint of limitation of the variation of the control signals,

a constraint on a starting area of the control signals;

a constraint on placing of closed-loop poles of the model.

6. A device for controlling the position and speed of a vehicle capable of moving in an autonomous manner and having at least one steered wheel, said device comprising:

circuitry configured to;

determine an overall path defining a course of the vehicle between a starting point and an endpoint, said overall path having a plurality of intermediate points between the starting point and the endpoint,

defining a position for each point of the overall path,

determine a current position of the vehicle,

generate, if the current position does not correspond to a point on the overall path, a local path connecting the current position of the vehicle to a point on the overall path, said local path having a plurality of points, a position and a speed being defined for each point of the local path, and

control, via a steering control signal, the steered wheel of the vehicle and control, via a speed control signal, the speed of the vehicle so that the vehicle moves along said local path,

wherein the computer generates the steering and speed control signals by convex optimization of linear matrix inequalities.