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US 6,285,940 B1Granted
Method for controlling an automatic gearbox
AssigneeZF Friedrichshafen AG
InventorsMarkus Henneken, Friedemann Jauch, Kai-Uwe Herbster, Franz-Josef Schuler, Thomas Mauz
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Abstract
When a cold start condition exists, an electronic gear control (4) calculates for an automatic transmission (3) driven by an internal combustion engine (1) the energy throughput of the internal combustion engine (1). The energy throughput is added up and compared with a limit value. The shift points of the automatic transmission (3) are pushed up to higher values as long as the calculated value remains less than the limit value.
Claims8
A method for control of an automatic transmission (3) driven by an internal combustion engine (1) comprising the steps of:
- testing, using an electronic gear control (4), whether a cold start condition exists, wherein when a cold start condition exists;
- determining, using said electronic gear control (4), from the torque (MM) generated by said internal combustion engine (1) and the rotational speed thereof (nMOT), the power (P) generated by said internal combustion engine (P(i)=MM(i)·nMOT(i)·K, i=1. 2 . . . n, k=constant);
- determining from two power values (P(i), P(i+1)) calculated within one time period (dt), an energy throughput (E(NEU)) (P(i)+P(i+1))·dt;
- adding (SUM(E)), via a characteristic line associated with the summed up energy throughput (SUM(E)) a first driving activity (FA(WARM)) (FA(WARM))=f(SUM(E)), the first driving activity (FA(WARM)) producing higher shift points of said automatic transmission and
- comparing, using said electronic gear control (3) the first driving activity (FA(WARM) with a second driving activity (FA(NORM)) (S10), wherein the second driving activity (FA(NORM)) is determined from the actual behavior of a driver.
2 more elements
Dependencies are inferred from the claim text.