Patent claim: The method according to claim 5 wherein performing the drive control of the vehicle based on the operation parameter and the selected operation mode of the vehicle further comprises after entering the HEVeco mediumelectricquantity mode if the speed of the vehicle is greater than a third speed threshold or the maximum discharge power of the power battery is less than or equal to a third discharge power threshold or the slope of the road where the vehicle runs on is greater than a third slope threshold controlling the vehicle to switch to a HEVeco highspeed mediumelectricquantity mode determining whether the required torque of the vehicle is less than or equal to a fourth torque threshold if the required torque of the vehicle is less than or equal to the fourth torque threshold controlling the synchronizer to engage controlling the engine unit and the first motor generator to generate electricity in parallel and controlling the second motor generator to stop if the required torque of the vehicle is greater than the fourth torque threshold determining whether the required torque of the vehicle is less than or equal to a sum of the first torque threshold and the fourth torque threshold if the required torque of the vehicle is less than or equal to the sum of the first torque threshold and the fourth torque threshold controlling the synchronizer to engage operating the engine unit with the fourth torque threshold operating the second motor generator with a difference between the required torque and the fourth torque threshold and controlling the first motor generator to stop if the required torque of the vehicle is greater than the sum of the first torque threshold and the fourth torque threshold determining whether the required torque of the vehicle is less than or equal to a sum of the first torque threshold the second torque threshold and the fourth torque threshold if the required torque of the vehicle is less than or equal to the sum of the first torque threshold the second torque threshold and the fourth torque threshold controlling the synchronizer to engage operating the engine unit with the fourth torque threshold operating the second motor generator with the first torque threshold and operating the first motor generator with a difference between the required torque and the sum of the first torque threshold and the fourth torque thresholdif the required torque of the vehicle is greater than the sum of the first torque threshold the second torque threshold and the fourth torque threshold controlling the synchronizer to engage calculating a third operation torque of the second motor generator according to the first torque threshold the second torque threshold and the fourth torque threshold operating the second motor generator with the third operation torque operating the engine unit with the fourth torque threshold and operating the first motor generator with a difference between the required torque and a sum of the third operation torque and the fourth torque threshold.

Related passage: Now processes effected in the changespeed switching means 130 will be explained using Fig.2.Fig.2 shows the speedcontrolling command Ss characteristics of the transmission mechanism using the abovementioned dog clutch for further improving in efficiency the operation areas of the engine 1 and the motor 19.The changespeed command Ss is determined on the basis of the acceleration pedal controlling amount and the automobile speed Vsp for example.The changespeed command Ss is found as such a value that the engine 1 acts with the maximum efficiency within the overall operation area by using a preexperiment a simulation or the like these values being stored in memory means not shown within the power train control unit 100.