Patent ID: 8918257
Filing Date: 2014-12-23
Classification: F16H,Y10T

Abstract:
1. A transmission control apparatus comprising: a plurality of linear solenoids, each of which acts on a hydraulic pressure adjustment valve incorporated in a vehicle transmission and generates an adjustment hydraulic pressure output corresponding to a supply current; and a supply current control apparatus that controls the supply current for the linear solenoid, wherein in the linear solenoid, an electromagnetic coil, a pressure sensor that detects an adjusted hydraulic pressure that has been adjusted through the adjustment hydraulic pressure output, and a single or a plurality of label resistors having a resistance value that serves as parameter data for correcting an inherent variation in the performance characteristic of the pressure sensor are integrated with one another, wherein the supply current control apparatus includes a control module and a driving circuit that operates with a supply voltage, which is the output voltage of a power supply on/off device connected between a vehicle battery and all the plurality of linear solenoids or between the vehicle battery and each of the linear solenoids, and with a control voltage, which is the output voltage of a constant voltage power source that is supplied with electric power from the vehicle battery, wherein the driving circuit is provided with a measurement circuit for measuring the resistance value of the label resistor and a control on/off device that is discretely and seriously connected with the other terminal of the linear solenoid, wherein the control module includes a microprocessor that generates a command signal for controlling the conduction state of the control on/off device, a RAM memory that collaborates with the microprocessor, a program memory, a nonvolatile data memory that is provided in part of the region of the program memory or is provided in such a way as to be separated from the program memory, and a multi-channel A/D converter to which, as a reference voltage, the control voltage is applied, wherein the program memory includes a control program that functions as a label resistor reading and conversion means, wherein in collaboration with the driving circuit, the microprocessor controls an energizing current for the electromagnetic coil in such a way that the adjusted hydraulic pressure detected by the pressure sensor becomes equal to a target setting hydraulic pressure, wherein the label resistor reading and conversion means operates in such a way as to calculate the resistance value of the label resistor based on the proportion of a measured current that flows from the measurement circuit to the label resistor to a measured voltage applied to the label resistor, in such a way as to calculate or selectively determine parameter data for correcting an inherent variation in the pressure detection characteristic of the pressure sensor, based on the calculated resistance value, and in such a way as to store the parameter data in the data memory or the RAM memory, and wherein the operation of the label resistor reading and conversion means is implemented at an operation start timing when the power switch is turned on, and even when the linear solenoid is replaced for maintenance, the pressure detection characteristic of the pressure sensor is adjusted in accordance with the resistance value of a label resistor added to a replacement linear solenoid.