Transmission control device and transmission control method

A transmission control method for controlling a transmission mounted in a vehicle, the transmission having:

• a variator;
• a sub-transmission mechanism arranged on an output side of the variator, the sub-transmission mechanism having a first speed gear position and a second speed gear position whose speed ratio is less than the first speed gear position;
• and
• a variator output side rotation sensor adapted to detect rotation speed on the output side of the variator and on an input side of the sub-transmission mechanism,
• the transmission control method comprising:
• determining failure of the variator output side rotation sensor;
• variably controlling a speed ratio of the variator, and in a case where the failure is determined, executing first control of restricting a shift range of the variator;
• variably controlling the gear position of the sub-transmission mechanism, and in a case where the failure is determined, executing second control of fixing the gear position of the sub-transmission mechanism to the first speed gear position;
• and
• executing the second control at a different timing from the first control in a case where the gear position of the sub-transmission mechanism upon a determination of the failure is the second speed gear position.

A transmission control device for controlling a transmission mounted in a vehicle, the transmission having:

• a variator;
• a sub-transmission mechanism arranged on an output side of the variator, the sub-transmission mechanism having a first speed gear position and a second speed gear position whose speed ratio is less than the first speed gear position;
• and
• a variator output side rotation sensor adapted to detect rotation speed on the output side of the variator and on an input side of the sub-transmission mechanism,
• the transmission control device comprising:
• failure determination means for determining failure of the variator output side rotation sensor;
• speed ratio control means for variably controlling a speed ratio of the variator, and in a case where the failure is determined, for executing first control of restricting a shift range of the variator;
• and
• gear position control means for variably controlling the gear position of the sub-transmission mechanism, and in a case where the failure is determined, for executing second control of fixing the gear position of the sub-transmission mechanism to the first speed gear position, wherein
• the gear position control means execute the second control at a different timing from the first control in a case where the gear position of the sub-transmission mechanism upon a determination of the failure is the second speed gear position.