Method for controlling an automatically operated motor vehicle transmission
AssigneeDr. Ing. h.c.F. Porsche Aktiengesellschaft
InventorsWilli Seidel, Joseph Petersmann
Life of this patent
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Abstract
A method for controlling an automatically actuated transmission for a motor vehicle, for improving behavior before curves and during braking, provides that a coasting function to suppress a shift or gear ratio changing process is initiated as soon as the accelerator pedal is quickly released. This coasting function is maintained until powered operation is again detected and the vehicle accelerates. Then a holding time is started during which the coasting function is started again as soon as the vehicle changes to coasting operation. The method is applicable to multi-step transmissions as well as continuously variable transmissions.
Claims13
Method for controlling an automatically operated transmission of a motor vehicle, especially one powered by an internal combustion engine, whose internal combustion engine can be influenced by a performance control element, with the gear ratio (ue) or the gear of transmission being adjusted automatically by at least one characterizing curve (RKLj) at least as a function of the throttle position (alpha(t)) and the engine rpm (nmot(t)), wherein the gear ratio (ue) or the gear of the transmission is kept constant when a change with time (dalpha (t)/dr) of the throttle position (alpha (t)) falls below a negative boundary value (-alphaga), and a holding time (Ti(SK(t))) that begins after the vehicle begins to accelerate has not yet expired, whereby in the case that coasting operation is again detected during the expiration of holding time (T1(SK(t)))bm, the gear ratio /ue) is one of kept constant and slowly adjusted until accelerated operation is again detected and the holding time (T1(SK(t))) has again elapsed.
Method for controlling an automatically operated transmission of a motor vehicle, especially one powered by an internal combustion engine, whose internal combustion engine can be influenced by a performance control element, with the gear ratio (ue) or the gear of transmission being adjusted automatically by at least one characterizing curve (RKLj) at least as a function of the throttle position (alpha(t)) and the engine rpm (nmot(t)), wherein when a first condition representative of coasting operation and slight transverse acceleration and sufficient distance from the limit of adhesive friction and sufficient distance from maximum speed is present and in multi-step transmissions a second condition representative of reaching a minimum deceleration in continuously variable transmissions initiates an increase in the gear ratio up to a travel-speed-dependent limiting value and, in multi-step transmissions, a downshift by one gear is initiated, and then, for a waiting time, the gear ratio or gear is determined until a holding time (T1(SK(t))) that begins after acceleration operation begins, has elapsed, whereby in the case where a new coasting operation is detected during expiration of the holding time (T1(SK(t))), the gear ratio continues to be one of kept constant and slowly adjusted until accelerated operation is recognized again and the holding time (T1(SK(t))) has once again elapsed.
Dependencies are inferred from the claim text.