Überbrückungskupplungssteuerung für ein automatisches Kraftfahrzeuggetriebe

摘要

A system (60) for controlling a lock-up clutch of a torque converter (22) in which a target speed ratio of the torque converter is determined by carrying out a fuzzy reasoning, which may be based on fuzzy production rules, using the engine load, the driving resistance and the current speed ratio as parameters. The degree of throttle opening, and the gradient resistance may also be used as parameters. The target speed ratio is used to determine a control value such that the lock-up clutch is controlled between a position at which the clutch is fully engaged and a position at which the clutch is fully not engaged including an intermediate position at which the clutch is partially engaged. A second fuzzy reasoning may be carried out based on second fuzzy production rules using the deviation between the target speed ratio and the current speed ratio and the change of the deviation as parameters and the results of the reasoning used to determine the control value. With the arrangement, the lock-up control can cope with various vehicle operating conditions so that the drivability and fuel consumption is improved while suppressing engine noise. The arrangement further enables the control that is better matched to the intention, decision-making and feelings of a human driver.