Process for correcting angle errors in an electronic compass in vehicles

US4725957A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gunther Alberter · Wendelstein, DE
• Harald Bauer · Ehningen, DE
• Gerhard Hettich · Roßtal, DE

Key dates

• Filing date: Oct 16, 1985
• Grant date: Feb 16, 1988
• Expiry date: Oct 16, 2005

Classification

• Technology area (CPC G): Physics
• CPC primary: G01C17/38
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A process for correcting inclination dependent angle errors when establishing the driving direction of vehicles with an electronic compass for navigation is suggested. The compass comprises a magnetometer (10) with an evaluation circuit (11) for computing the driving direction. For compensating inclination dependent angle errors on the indicator of the drive direction the inclination angle of the earth field is fed into the evaluation circuit (11) as a calibration dimension (E), subsequently the inclination angle (.psi.) of the vehicle is established cyclically by means of an inclination measuring device (12) and then the corrected driving direction (.theta.) is established from the computed driving direction (.theta.') as well as from the calibration dimension (E) and the angle of inclination (.psi.) in accordance with the equation .theta.=f (.theta.',.psi.,E). This corrected driving direction can then be further processed or issued to an indicator (13) (FIG. 1).