grinding rubbin sound in a continuous pattern

The other day I was driving and dozed off to sleep and ran hit my front passenger side bumper then ran over something....no major damage but scratches to the bumper. ..I flat the drivers and back driverside wheels and parked next day I got new tired and now when I drive I here this grinding now frm the bottom front of my car and the tire light comes on I go to the tire place and he tells me my sensors work fine and the pressure is ok when I speed up I here it rubbing faster when I slow down the noise go slower