Adaptive control of a flow control solenoid

摘要

A vehicle includes an engine, a transmission, and a controller which executes a method. The transmission includes a clutch having an actuator which applies the clutch using position-based control logic. The transmission also includes a fluid pump and a variable-force or other solenoid valve positioned downstream of the pump and upstream of the clutch. The valve outputs a flow rate (Q) for a corresponding solenoid control current (I). The controller adapts a calibrated Q vs. I characteristic table of the valve for different transmission temperatures by applying closed-loop position control signals to the actuator at the different transmission temperatures and recording a null point(s) describing the corresponding solenoid control current (I) at a zero flow rate condition. The controller calculates an offset value for solenoid control current (I) using the recorded null point(s), applies the offset value to the characteristic table, and controls the clutch using the adapted characteristic table.

主权项

1. A vehicle comprising:
an engine; a transmission which is connected to the engine, and which includes:
a clutch having a clutch actuator, wherein the clutch is applied via the clutch actuator using position-based control logic;a fluid pump; anda solenoid valve positioned downstream of the fluid pump and upstream of the clutch, wherein the solenoid valve is configured to output a flow rate (Q) for a corresponding solenoid control current (I); and a controller in communication with the clutch actuator, wherein the controller includes a processor with tangible, non-transitory memory on which is recorded instructions for adapting a calibrated Q vs. I characteristic table of the solenoid valve for different transmission temperatures, and wherein the processor is operable to execute the instructions only under predetermined conditions to thereby:
apply closed-loop position control signals to the clutch actuator, using the position-based control logic, at the different transmission temperatures;record, at each of the different transmission temperatures, a null point describing the corresponding solenoid control current (I) at a zero flow rate (Q=0) condition;calculate an offset value for the corresponding solenoid control current (I) using the recorded null point;apply the offset value to the calibrated Q vs. I characteristic table to thereby adapt the calibrated Q vs. I characteristic table; andcontrol the clutch using the adapted Q vs. I characteristic table.