Power transmission control apparatus for vehicle

A power transmission control apparatus for a vehicle comprising:

• a transmission which includes an input shaft for receiving power from an engine of the vehicle;
• an output shaft for outputting power to drive wheels of the vehicle, one or a plurality of sleeves provided on a selected one of the input shaft and the output shaft such that the sleeves cannot rotate and can move axially in relation to the selected shaft, and one or a plurality of synchronization mechanisms provided for the sleeve(s), each sleeve selectively establishing, in accordance with sleeve position, which is the axial position of the sleeve, an established state in which the sleeve couples with a corresponding free rotating gear rotatably provided on the selected one of the input shaft and the output shaft so as to non-rotatably fix the free rotating gear to the selected one of the input shaft and the output shaft, to thereby establish a corresponding gear stage or an un-established state in which the sleeve does not couple with the corresponding free rotating gear and allows the free rotating gear to rotate in relation to the selected one of the input shaft and the output shaft, whereby the corresponding gear stage is not established, and each of the synchronization mechanisms performing synchronization operation, when the sleeve position of the corresponding sleeve is changed from a position corresponding to the un-established state toward a position corresponding to the established state, so as to apply friction torque to the corresponding sleeve and the corresponding free rotating gear such that the rotational speed difference therebetween decreases;
• a clutch interposed between an output shaft of the engine and the input shaft of the transmission and adapted to change clutch torque, which is the maximum torque which can be transmitted between the output shaft of the engine and the input shaft of the transmission, through adjustment of clutch position, which is than axial position of the clutch;
• and
• control means for controlling the sleeve position(s) of the sleeve(s) and the clutch position of the clutch, by making use of respective actuators, in accordance with a traveling state of the vehicle, wherein
• the control means includes obtaining means operating such that, in a state in which the vehicle is stopped, the one sleeve or all the sleeves of the transmission are in the un-established state, the clutch is in a disengaged state in which no power transmission route is formed between the output shaft of the engine and the input shaft of the transmission, and the engine is operating, the obtaining means adjusts the sleeve position of a specific sleeve, which is the one sleeve or any one of the plurality of sleeves, so as to realize a synchronization state in which the specific sleeve is in the un-established state and the synchronization mechanism corresponding to the specific sleeve performs the synchronization operation;
• and, in the synchronization state, the obtaining means adjusts the clutch position and obtains, as an engagement start point, a clutch position corresponding to a transition between an engaged state in which a power transmission route is formed between the output shaft of the engine and the input shaft of the transmission, and the disengaged state in which the power transmission route is not formed.