Patent ID: 7363122

Claim:
A method for controlling a hybrid drive of a vehicle, the hybrid drive including an internal combustion engine and at least one electric machine as drive motors, and output shafts of the drive motors being operatively connectable to a drive train of the vehicle, the method comprising: in response to a negative torque demand on the drive train of the vehicle, controlling the at least one electric machine in generating an operating mode based on a control map; wherein the control map is bounded by limit curves which limit an operating range of a brake energy regeneration, a minimum limit curve defining a transition between a purely regenerative operation including active input of electric power into a vehicle electrical system and a purely regenerative operation including an electric power demand placed on the vehicle electrical system, and a maximum limit curve defining a transition between a purely regenerative operation including active input of electric power into the vehicle electrical system and a combined regenerative and mechanical operation, and wherein the maximum limit curve is a function of the vehicle speed, and at each speed has a value which is a lower of: (a) a maximum torque of the at least one electric machine and (b) a torque at which a maximum battery current can be produced.