US 12,441,324 B2
Device and method for automatic detection of road conditions for vehicle applications
Fabio Passaniti, Syracuse (IT); and Enrico Rosario Alessi, Catania (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed on Jul. 22, 2022, as Appl. No. 17/871,463.
Claims priority of application No. 102021000021680 (IT), filed on Aug. 10, 2021.
Prior Publication US 2023/0045861 A1, Feb. 16, 2023
Int. Cl. B60W 40/06 (2012.01); B60W 40/105 (2012.01); G01R 29/12 (2006.01); G01R 29/24 (2006.01)
CPC B60W 40/06 (2013.01) [B60W 40/105 (2013.01); G01R 29/12 (2013.01); G01R 29/24 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A road condition detection device, configured to be coupled to a wheel of a vehicle and to a vehicle controller, the road condition detection device comprising:
an electrostatic charge variation sensor, which, in operation, provides a charge variation signal indicative of an electrostatic charge variation associated with rotation of the wheel; and
processing circuitry, coupled to the electrostatic charge variation sensor, wherein the processing circuitry, in operation, receives the charge variation signal, and receives a rotation speed signal indicative of the rotation speed of the wheel,
wherein the processing circuitry, in operation, jointly processes the rotation speed signal and the charge variation signal to detect a road condition between a wet condition and a dry condition based on an amplitude of the charge variation signal and on the rotation speed signal, wherein the processing circuitry, in operation:
determines, in a trend in a frequency domain of the charge variation signal, a peak amplitude of a fundamental frequency at the rotation speed of the wheel;
compares the peak amplitude with a threshold amplitude to determine one of the dry road condition and the wet road condition;
determines a frequency distance between the fundamental frequency and a frequency associated with the rotational speed of the wheel;
compares the frequency distance with a threshold distance to determine the one of the dry road condition and the wet road condition;
determines the dry road condition in response to the frequency distance being less than the threshold distance and the peak amplitude being greater than the threshold amplitude;
determines the wet road condition in response to the frequency distance not being less than the threshold distance or the peak amplitude not being greater than the threshold amplitude;
generates a vehicle control signal indicative of the determined road condition; and
provides the generated vehicle control signal to the vehicle controller to control one or more vehicle control systems coupled to the vehicle controller.