Patent ID: 8326475

Claim:
A hybrid drive device comprising: a rotary electric machine coupled to an engine via a transfer clutch; a fluid power transmission device including a lock-up clutch and having a pump impeller and a turbine runner; a transmission device coupled to the rotary electric machine via the fluid power transmission device to receive a driving force produced by one or both of the engine and the rotary electric machine each serving as a driving force source and to output the received driving force after changing a speed thereof; an engine startup control device that starts up the engine, from a state in which the driving force is transferred from the rotary electric machine to the transmission device with the engine stationary and with the lock-up clutch engaged, by executing rotational speed control to bring a rotational speed of the rotary electric machine to a target rotational speed with the lock-up clutch slipping, and engaging the transfer clutch; a transfer torque estimation unit for estimating a transfer torque transferred by the lock-up clutch with the lock-up clutch slipping; and a target rotational speed determination unit for determining the target rotational speed of the rotary electric machine to be achieved in the rotational speed control on the basis of the transfer torque estimated by the transfer torque estimation unit, a target transmission device input torque of the transmission device determined on the basis of an operating state of a vehicle, and a turbine speed of the turbine runner, wherein the engine startup control device starts up the engine by controlling the rotational speed of the rotary electric machine to the target rotational speed determined by the target rotational speed determination unit, and the transfer torque estimation unit includes a transfer torque prediction unit including a control delay element for outputting a predicted transfer torque with a control response delay with respect to a target transfer torque command provided to the lock-up clutch, and estimates the transfer torque on the basis of the predicted transfer torque output from the transfer torque prediction unit.