Safety system for an automatic transmission

• Main Author: SIGG PETER
• Format: Patent
• Language: English
• Published: 28.05.2002
• Edition: 7
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MECHANICAL ENGINEERING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THERMAL INSULATION IN GENERAL; WEAPONS

For an automatic transmission (2), a safety system is proposed in which a virtual reduction ratio is calculated when a driver moves the selector lever from a drive position to neutral and then from neutral back to a drive position. The virtual reduction ratio is then compared with the reduction ratio resulting from a shift characteristic field. In case of divergence, the virtual reduction ratio is assigned to a characteristic field having a linearly constant reduction ratio surrounded by a reduction ratio range. The electronic control unit (5) selects as a set reduction ratio, the one containing in its range the virtual reduction ratio.