Method and system of determining the absolute velocity of a vehicle
AssigneeNira Dynamics AB
InventorFredrik Gustavsson
Life of this patent
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Abstract
A method of determining the velocity (ν) of a vehicle is provided. The vehicle has at least one pair of a front and a rear wheel which are spaced by a wheel spacing (B). Front and rear wheel speed signals (ω) are determined which are indicative of the time dependent behavior of the front and rear wheel speeds, respectively. The front and rear wheel speed signals (ω) are correlated in order to determine a specific correlation feature indicative of the time delay (τ) between the front wheel and rear wheel speed signals. The velocity (ν) of the vehicle is determined based on said correlation feature and the wheel spacing (B).
Claims14
A method of determining the velocity (ν) of a vehicle having at least one pair of a front and a rear wheel which are spaced by a wheel spacing (B), the method comprising for at least one pair of wheels:
- a) determining front and rear wheel speed signals (ω) indicative of the time dependent behavior of the front and rear wheel speeds, respectively;
- b) correlating the front and rear wheel speed signals (ω) in order to determine a specific correlation feature indicative of the time delay (τ) between the front wheel and rear wheel speed signals;
- c) determining the velocity (ν) of the vehicle based on said correlation feature and the wheel spacing (B).
The method of any one of the preceding claims, wherein the radii of the front and the rear wheels (r) are determined on the basis of the obtained vehicle velocity (ν).
The method of any one of the preceding claims, wherein the wheel speed signals (ω) are provided by wheel speed sensors of an antilock braking system (ABS).
The method of any one of the preceding claims, wherein the absolute velocity thus determined is used for road-friction monitoring.
The method of any one of the preceding claims, wherein the absolute velocity thus determined is used as input for control systems such as ABS, dynamic stability systems, traction control systems, anti-spin systems and AWD/4WD vehicles.
A system for determining the velocity (ν) of a vehicle having at least one pair of a front and a rear wheel which are spaced by a wheel spacing (B), the system comprising:
- a) wheel speed sensors arranged to provide front and rear wheel speed signals (ω) indicative of the time dependent behavior of the front and rear wheel speeds, respectively;
- b) a correlation unit arranged to correlate the front and rear wheel speed signals (ω) in order to determine a specific correlation feature indicative of the time delay (τ) between the front wheel and rear wheel speed signals;
- and to determine the velocity (ν) of the vehicle based on the wheel spacing (B) and the correlation feature thus determined.
A computer program product including program code for carrying out a method, when executed on a processing system, of determining the velocity (ν) of a vehicle having at least one pair of a front and a rear wheel which are spaced by a wheel spacing (B), the program code being arranged to:
- a) determine front and rear wheel speed signals (ω) indicative of the time dependent behavior of the front and rear wheel speeds, respectively;
- b) correlate the front and rear wheel speed signals (ω) in order to determine a specific correlation feature indicative of the time delay (τ) between the front wheel and rear wheel speed signals;
- c) determine the velocity (ν) of the vehicle based on said correlation feature and the wheel spacing (B).
Dependencies are inferred from the claim text.