Mode control of hybrid vehicle

摘要

A control method and system (10 see fig 1) for propelling a hybrid vehicle comprises launching the vehicle using a secondary power source (4 see fig 1) and then activating a primary power source (2 see fig 1) when a calculated vehicle weight and driver torque request exceed respective threshold values. A controller 110 determines the weight based on initial acceleration of the vehicle. The system (10) may improve vehicle driveability and performance. The primary power source (2) may be an internal combustion engine 116 in parallel with the secondary power source (4) which is typically an electric motor 146. Alternatively, a fuel cell engine (12 see fig 2b) may be used as the primary power source. An alternative series layout comprises a generator (18a see fig 2a) for driving a motor (18b see fig 2a).