Method of alerting a vehicle driver to different types of traction losses

• US 5,495,225 A
• Filed: 07/21/1994
• Issued: 02/27/1996
• Est. Priority Date: 01/23/1992
• Status: Expired due to Fees

• Current Assignee: Toyoda Machine Works, Ltd.
• Original Assignee: Zexel Torsen, Inc.
• Inventors: Ostertag, Steven E., May, Kenneth A.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): Oda, Christine K.
• Application Number:
  US08/284,571
• Time in Patent Office: 586 Days
• Field of Search: 340/438, 340/439, 340/453, 364/426.02, 364/426.03, 364/426.01, 303/92
• US Class Current: 73/439
• CPC Class Codes: B60R 16/0237 circuits concerning the atmospheric environment meteorology G01W
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention

Abstract

A warning system alerts a driver of a motor vehicle to different types of traction losses. A first sensing circuit (10) detects a loss of wheel adhesion by monitoring a vehicle drive line for a pronounced vibration within a range of between ten and fifteen hertz. A second sensing circuit (12) monitors a brake light circuit to detect application of a vehicle brake. A logic circuit (28) combines outputs (A and B) from the first and second sensing circuits and outputs command signals (C and D) that distinguish between a loss of wheel adhesion due to wheel skidding and a loss of wheel adhesion due to wheel slipping. A warning device includes two indicators (36 and 38) that receive the respective command signals and produce sensorially distinguishable warning signals for eliciting different responses from the driver.

Claims

1. A method of alerting a vehicle driver to different vehicle operating conditions comprising the steps of:

sensing the vehicle operating conditions including rotation of a drive wheel with respect to the drive wheel'"'"'s traction surface;

distinguishing the operating conditions between;

(a) wheel skidding in which the drive wheel rotates slower than required for maintaining adhesion with the traction surface; and

(b) wheel slipping in which the drive wheel rotates faster than required for maintaining adhesion with the traction surface; and

producing sensorially distinguishable warning signals for eliciting different responses from the vehicle driver in response to the conditions of wheel slipping and wheel skidding.

2. The method of claim 1 in which said step of producing warning signals includes producing warning signals that are sensorially distinguishable by the driver without changing a driver'"'"'s line of sight away from the traction surface.

3. The method of claim 1 in which said step of producing warning signals includes producing respective warning signals that are suggestive of wheel skidding and wheel slipping.

4. The method of claim 2 in which said warning signals are audible.