Drift sensor for land vehicles

• US 6,321,146 B1
• Filed: 08/06/1998
• Issued: 11/20/2001
• Est. Priority Date: 08/07/1997
• Status: Expired due to Fees

• Current Assignee: Litef GmbH (Northrop Grumman Corporation)
• Original Assignee: Litef GmbH (Northrop Grumman Corporation)
• Inventors: Schnell, Jürgen
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US09/129,818
• Time in Patent Office: 1,202 Days
• Field of Search: 701/23, 701/24, 701/25, 701/26, 701/27, 701/28, 701/200, 701/207, 318/587, 318/576, 318/577, 318/580, 180/167, 180/168, 180/169
• US Class Current: 701/23
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00

Abstract

A sensor is provided on the vehicle of a driverless transport system. The sensor is based on the principle of a computer mouse for ascertaining either a drift angle Δα or the transverse movement is detected as a path difference Δq whereby lateral drift due, for example, to roadway covering irregularities and to curves, is detected directly. A considerable improvement in the tracking accuracy of driverless transport vehicles is thereby provided.

Claims

1. In an automatic guided land vehicle of the type that includes a navigation device for integrated navigation for detecting remotely-spaced sequential correction points fitted into a floor or roadway covering defining a predetermined route to assist tracking and maintain navigation accuracy by the use of a navigation algorithm, the improvement comprising, in combination:

a) said land vehicle including a sensor for generating a signal independent of said navigation device; and

b) said sensor including means comprising a trailing wheel for detecting the drift angle and path difference resulting from movements occurring transverse to the longitudinal axis of said vehicle; and

c) said navigation algorithm being arranged to provide a course correction based, in part, upon the output of said sensor.

2. A driverless land vehicle as defined in claim 1 wherein said means further includes:

a) a first friction roller; and

b) a second friction roller, said roller being arranged in accordance with the principle of the computer mouse.

3. A driverless land vehicle as defined in claim 1 wherein said means further includes:

a) a first friction ball; and

b) a second friction ball, said ball being arranged in accordance with the principle of the computer mouse.

4. An automatic guided land vehicle as defined in claim 1 wherein said navigation algorithm derives vehicle alignment error corrected for measured movements transverse to the longitudinal axis of said vehicle.