Tire burst prediction device

• US 6,879,938 B2
• Filed: 10/12/2001
• Issued: 04/12/2005
• Est. Priority Date: 10/13/2000
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Umeno, Takaji, Ono, Eiichi, Asano, Katsuhiro, Mori, Yukio, Ohashi, Hideki, Naito, Toshiharu, Kamiya, {umlaut over (K)}azuhiro
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US10/380,108
• Publication Number:
  US 20040015312A1
• Time in Patent Office: 1,278 Days
• Field of Search: 702/185, 702/41, 702/56, 702/145, 702/147, 702/148, 731/46, 701/70, 701/71, 701/72, 701/73, 701/76, 701/82, 701/92, 390/426.33
• US Class Current: 702/185
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00
• CPC Class Codes: B60C 23/062 Frequency spectrum analysis of wheel speed signals, e.g. using Fourier transformation

Abstract

A tire burst predicting device which can predict occurrence of bursting of a tire and gives an alarm properly is provided. A break point frequency is estimated on the basis of time series data of wheel speed detected at a wheel speed sensor from frequency response of a first order model to which a transmission characteristic from a road surface disturbance to a wheel speed is approximated. A braking force gradient corresponding to the estimated break point frequency is estimated, on the basis of a map, which is prestored, representing a relationship between break point frequencies and braking force gradients. Extra high frequency components are eliminated from the estimated braking force gradient by a low pass filter to reduce estimation dispersion. Differentiators detect changing speed of the braking force gradient. An alarm is given when there is a possibility of bursting of tire when the detected changing speed reaches or exceeds a predetermined threshold value.

Claims

1. A tire burst predicting device comprising:

wheel speed detecting means which detects a speed of a wheel;

ground contact state estimating means which estimates a physical quantity representing a ground contact state between the wheel and a road surface on the basis of the detected wheel speed;

rate of change detecting means which detects a rate of change of the estimated physical quantity representing the ground contact state between the wheel and the road surface; and

predicting means which predicts occurrence of bursting of the wheel by judging whether or not the detected rate of change is a value outside of a predetermined range.

2. The tire burst predicting device of claim 1 further comprising alarming means which gives an alarm relating to bursting of the wheel, wherein the predicting means judges whether or not the detected rate of change is a value outside of the predetermined range, and the alarming means gives the alarm in a case in which the detected rate of change is a value outside of the predetermined range.

3. The tire burst predicting device of claim 1 further comprising driving force suppressing means which suppresses a driving force of the wheel, wherein the predicting means judges whether or not the detected rate of change is a value outside of the predetermined range, and the driving force suppressing means suppresses the driving force of the wheel in a case in which the detected rate of change is a value outside of the predetermined range.

4. The tire burst predicting device of claim 2 further comprising driving force suppressing means which suppresses a driving force of the wheel, wherein the predicting means judges whether or not the detected rate of change is a value outside of the predetermined range, and the driving force suppressing means suppresses the driving force of the wheel in a case in which the detected rate of change is a value outside of the predetermined range.

5. The tire burst predicting device of claim 1, wherein the ground contact state estimating means comprises smoothing means which smoothes the physical quantity representing the ground contact state, and a differentiator which differentiates the smoothed physical quantity representing the ground contact state.

6.The tire burst predicting device of claim 2, wherein the ground contact state estimating means comprises smoothing means which smoothes the physical quantity representing the ground contact state, and a differentiator which differentiates the smoothed physical quantity representing the ground contact state.

6. The tire burst predicting device of claim 3, wherein the ground contact state estimating means comprises smoothing means which smoothes the physical quantity representing the ground contact state, and a differentiator which differentiates the smoothed physical quantity representing the ground contact state.