HYDRAULIC OVER/UNDERSHOOT PROTECTION FOR TRANSMISSION CLUTCH CONTROL

摘要

A vehicle automatic speed change power transmission control includes a control arrangement with overshoot/undershoot protection logic. The control is used with an electro-hydraulic pressure control module featuring a linear solenoid, and which supplies a hydraulically-actuated clutch configured to effect gear changes. The overshoot/undershoot protection logic is configured to detect when a commanded increase/decrease clutch pressure satisfies a clutch pressure threshold and to then activate the protection logic. Once the protection logic is activated, large command pressures increases/decreases are implemented in a series of stages having variable gains. The first stage has an aggressive gain and achieves 50-80% of the commanded clutch pressure. The second stage has a reduced gain and achieves 90% of the commanded clutch pressure. The third stage has a still further reduced gain and achieves about 100% of the commanded clutch pressure.