Patent ID: 9174630
Filing Date: 2015-11-03
Classification: B60W,B60Y,F16H

Abstract:
1. A control device for a transmission including m (m≧3) solenoid valves, each solenoid being paired with a feedback current sensor used to provide feedback to the respective solenoid valve, the solenoid valves configured to establish a plurality of shift speeds by engaging n1 (2≦n1<m) engagement elements using hydraulic pressures of n1 solenoid valves among the m solenoid valves, and the solenoid valves configured to establish a braking torque on an output shaft by engaging n2 solenoid valves (n1<n2≦m), the control device comprising: an actual current value detection unit that detects respective values of actual currents flowing through each solenoid of the m solenoid valves by measuring current passing through the respective feedback current sensors oriented between each of the m solenoid valves and ground; a current threshold determination unit that calculates respective current thresholds for each of the n2 solenoid valves, each respective current threshold for a respective solenoid valve calculated on a basis that the respective solenoid valve of the n2 solenoid valves is slipped and each of the n1 engagement elements corresponding to each of the n1 solenoid valves is engaged, while each of the n2 solenoid valves is supplied with hydraulic pressure; and a determination unit that determines whether or not braking torque is generated on an output shaft of the transmission by comparing the detected actual current values for solenoids of the n2 solenoid valves with their respective current threshold value, wherein the respective current threshold values are varied on the basis of a speed change ratio established by engaging engagement elements corresponding to the n1 solenoid valves among the n2 solenoid valves.