ROAD CONDITION DETERMINATION METHOD

• Main Authors: HANATSUKA Yasushi, GOTO, Takato
• Format: Patent
• Language: English; French; German
• Published: 23.01.2019
• Subjects: ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE ORDIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; DEVICES OR ARRANGEMENTS RELATED TO TYRES; PERFORMING OPERATIONS; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OFVEHICLES; REPAIRING, OR CONNECTING VALVES TO, INFLATABLE ELASTIC BODIESIN GENERAL; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TOTHE CONTROL OF A PARTICULAR SUB-UNIT; TRANSPORTING; TYRE CHANGING OR REPAIRING; TYRE INFLATION; VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES; VEHICLE TYRES; VEHICLES IN GENERAL

In a method for determining a road surface condition, the speed of calculation is improved by applying an appropriate path limitation. To further improve the accuracy of determination, a time-series waveform of tire vibration detected by an acceleration sensor is windowed at time width T by a windowing means, and time-series waveforms of tire vibration in the respective time windows are extracted before feature vectors X i of the respective time windows are calculated. Then kernel functions K A (X, Y) are calculated from the feature vectors X i for the respective time windows and road surface feature vectors Y i , which are feature vectors for the respective time windows calculated from time-series waveforms of tire vibration having been determined in advance for distinctive road surface conditions. In doing so, the kernel functions are calculated after weighting respective paths by weighting parameters É (i, j) using a time-series waveform length corresponding value in the time-series waveform of tire vibration as measured and a previously determined time-series waveform length corresponding value in the time-series waveform of tire vibration.