SYSTEM FOR CONTROLLING A VEHICLE WITH DETERMINATION OF ITS INSTANTANEOUS SPEED RELATIVE TO THE GROUND
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Accused Products
Abstract
A vehicle control system is described which comprises a determination of the instantaneous ground speed of a vehicle having at least two wheels, each equipped with a sensor (11) designed to supply a measurement that is a function of the movement of said wheel. It comprises a module indicating the circumferential speed (Vr) of each of these wheels from the corresponding sensor, a first vehicle speed indicator producing an overall speed estimation of the vehicle relative to the ground as a function of the indication from the module for at least one wheel, an acceleration sensor on board the vehicle (285) supplying a measurement that is a function of at least one longitudinal acceleration component of the vehicle (γmes), and a second vehicle speed indicator able to produce an estimation of the overall speed of the vehicle relative to the ground by integration of an acceleration indication derived from the acceleration sensor when the estimation resulting from the first indicator is not valid. The system also comprises a diagnostic stage suitable for testing the reliability of each of these indications obtained from the module as a function of the condition of the corresponding wheel at a considered instant and an estimator of the acceleration of the movement of the vehicle (γmvt) relative to the ground (280) as a function of the measurement from the acceleration sensor and of at least one acceleration measurement (Ωr) obtained from said wheel sensors, to take account in particular of the slope δy of the ground on which the vehicle is rolling relative to the horizontal.
47 Citations
13 Claims
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1-5. -5. (canceled)
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6. Vehicle control system for determining an instantaneous ground speed of a vehicle that includes at least two wheels, each wheel being equipped with a sensor designed to supply a measurement that is a function of a movement of the wheel, the system comprising:
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(a) a module suitable for supplying at each instant an indication that is a function of a circumferential wheel speed of each of the wheels from a corresponding sensor; (b) an acceleration sensor on board the vehicle suitable for supplying a measurement that is a function of at least one longitudinal acceleration component of the vehicle, and (c) a vehicle speed indicator suitable for producing speed estimations of the vehicle relative to a ground surface as a function of indications deriving from the module and the sensor for at least one wheel, wherein the vehicle speed indicator includes; (i) a diagnostic stage suitable for testing at least one road grip condition of the wheels to reject a speed indication deriving from a corresponding module that is not valid to determine a speed of the vehicle relative to the ground surface, (ii) a test stage suitable for determining if there is at least one wheel for which a speed indication has not been rejected, (iii) a first module for supplying, in an event of an affirmative response to a test from the test stage, a determination of the speed of the vehicle from a non-rejected indication, (iv) an estimator that is operative in case of a negative response to a test from the test stage for supplying an estimation of an acceleration of a movement of the vehicle (γ
mvt) relative to the ground surface, as a function of a measurement from the acceleration sensor and of at least one angular acceleration measurement obtained from at least one wheel sensor, and(v) a second module for integration of a function of the acceleration of the movement produced by the estimator from a determination of a vehicle speed at a preceding instant, to determine the speed of the vehicle relative to the ground surface in an event of a negative response to a test from the test stage. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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Specification