Negative-torque downshift execution for fixed-gear transmissions

US9242545B2 · kind B2 · utility

Assignee

• GM GLOBAL TECHNOLOGY OPERATIONS LLC · US

Inventors

• Craig J. Hawkins · Howell, US
• Adam J. Heisel · South Lyon, US
• Christopher E. Whitney · Commerce, US
• Matthew D. Whitton · Howell, US
• Roger Joseph Rademacher · Holt, US
• Keith D. Van Maanen · Berkley, US

Key dates

• Filing date: Oct 20, 2010
• Grant date: Jan 26, 2016
• Expiry date: Oct 15, 2033

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/62
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A method of executing a downshift in a fixed-gear powertrain having an input node and an output node related by a starting speed ratio before the downshift and a finishing speed ratio after is provided. The downshift includes a torque phase and an inertia phase. A starting output torque is calculated as a function of a starting driver request. An electric machine applies a starting regenerative input torque which is calculated as substantially equal to the starting output torque divided by the starting speed ratio. A finishing output torque is calculated as a function of a finishing driver request. The electric machine applies a finishing regenerative input torque which is calculated as substantially equal to the finishing output torque divided by the finishing speed ratio.