Transmission, control apparatus of transmission, and method of controlling transmission

A transmission comprising:

• a transmission unit including a hydraulic pressure unit, the transmission unit being configured to perform shifting operation by using a control pressure derived from an actuating oil to be supplied to the hydraulic pressure unit;
• a hydraulic pressure circuit including a line pressure adjusting valve, a control pressure adjusting valve, a line pressure sensor, and a control pressure sensor, the line pressure adjusting valve being configured to adjust a line pressure derived from the actuating oil that is to be supplied from a hydraulic pressure supply source, the control pressure adjusting valve being configured to adjust the control pressure that is derived from the actuating oil and that is to be applied to the hydraulic pressure unit, the line pressure sensor being configured to detect the line pressure, the control pressure sensor being configured to detect the control pressure;
• an abnormality detector configured to detect an abnormality of the line pressure sensor and an abnormality of the control pressure sensor;
• and
• a controller configured to perform first control operation, second control operation, or both, the first control operation being performed when the abnormality of the line pressure sensor is detected, the second control operation being performed when the abnormality of the control pressure sensor is detected,
• the control pressure adjusting valve being provided in an oil path that couples the line pressure adjusting valve and the hydraulic pressure unit to each other,
• the actuating oil that has flowed from the line pressure adjusting valve being supplied to the hydraulic pressure unit via the control pressure adjusting valve,
• the controller being configured to control the shifting operation of the transmission unit by controlling, as the first control operation, the control pressure adjusting value to allow the line pressure and the control pressure to have a correlation with each other and by using, as a value of the line pressure, a value calculated on a basis of a detected value of the control pressure detected by the control pressure sensor,
• the controller being configured to control the shifting operation of the transmission unit by controlling, as the second control operation, the control pressure adjusting valve to allow the line pressure and the control pressure to have a correlation with each other and by using, as a value of the control pressure, a value calculated on a basis of a detected value of the line pressure detected by the line pressure sensor,
• wherein the controller allows the control pressure adjusting valve to be fixed at a predetermined position where the line pressure and the control pressure have a correlation with each other when the abnormality of the line pressure sensor is detected, or when the abnormality of the control pressure sensor is detected.

A method of controlling a transmission, the transmission including a hydraulic pressure unit, the transmission being configured to perform shifting operation by using a control pressure derived from an actuating oil, the actuating oil being supplied from a hydraulic pressure circuit to the hydraulic pressure unit, the method comprising:

• detecting, by a control pressure sensor, the control pressure that is derived from the actuating oil and that is to be applied to the hydraulic pressure unit;
• detecting, by a line pressure sensor, a line pressure derived from the actuating oil in the hydraulic pressure circuit;
• determining whether an abnormality of the line pressure sensor occurs;
• determining whether an abnormality of the control pressure sensor occurs;
• performing first control operation, second control operation, or both, the first control operation being performed when the abnormality of the line pressure sensor is detected, the second control operation being performed when the abnormality of the control pressure sensor is detected;
• controlling the shifting operation of the transmission by controlling, as the first control operation, a control pressure adjusting valve to allow the line pressure and the control pressure to have a correlation with each other and by using, as a value of the line pressure, a value calculated on a basis of a detected value of the control pressure detected by the control pressure sensor, the control pressure adjusting valve being configured to adjust the control pressure that is derived from the actuating oil and that is to be applied to the hydraulic pressure unit;
• and
• controlling the shifting operation of the transmission by controlling, as the second control operation, the control pressure adjusting valve to allow the line pressure and the control pressure to have a correlation with each other and by using, as a value of the control pressure, a value calculated on a basis of a detected value of the line pressure detected by the line pressure sensor,
• wherein the controller allows the control pressure adjusting valve to be fixed at a predetermined position where the line pressure and the control pressure have a correlation with each other when the abnormality of the line pressure sensor is detected, or when the abnormality of the control pressure sensor is detected.