Patent ID: 8392077
Filing Date: 2013-03-05
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 adjusted hydraulic pressure output corresponding to a supply current; and a supply current control apparatus that controls the supply current for the linear solenoid, wherein the linear solenoid is configured with a label resistor having a resistance value that serves as parameter data for correcting an inherent variation in the performance characteristic of the linear solenoid and an electromagnetic coil that are integrated with each other, wherein the supply current control apparatus includes 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; a control module; and a control on/off device that is included in the driving circuit and is individually connected in series with the other terminal of the linear solenoid, wherein the driving circuit is provided with a measurement circuit for energizing the label resistor and measuring the resistance value of the label resistor, wherein the control module includes a microprocessor that generates a command signal for controlling the conduction state of the control on/off device, a program memory that collaborates with the microprocessor, 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 is provided with control programs that function as a correction control constant storage means and a label resistor reading and conversion means, wherein the correction control constant storage means collaborates with an adjustment tool, which is externally connected, so as to measure a current control constant for the driving circuit, calculates a correction coefficient for obtaining a supply current that coincides with a target current even when there exists the inherent variation of a circuit component, and stores the correction coefficient in the program memory or the data memory, and 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 the inherent variation of the linear solenoid, based on the calculated resistance value, and in such a way as to store the parameter data in the data memory or a RAM memory; said operation is implemented at an operation start timing when a power switch is turned on; and even when the linear solenoid is replaced for maintenance, the supply current is controlled in accordance with the resistance value of the label resistor added to the replaced linear solenoid.