| 摘要 |
<p>Methods and apparatus are provided for predicting ambient air temperature (PAT) around a vehicle (and partly controlling vehicle operation) based on Mass Air Flow (MAF), Vehicle Speed (VSS), Inlet Air Temperature (IAT), Engine Run Time (ERT) and the last PAT value (LPAT). If MAF,VSS are below thresholds C 1, C 2 and ERT is below threshold C 4, then PAT is set equal to the smaller of IAT or LPAT. If MAF,VSS,ERT exceed C 1, C 2, C 4, as for example, in steady run operation, then after an interval PAT approaches IAT-C 5 +/-C 6 where C 5 and C 6 are stored parameters. An idle counter increments when MAF<C 1, VSS<C 2 is TRUE and decrements by parameter C 3 when FALSE and must reach zero before the PAT steady run value is set. This improves prediction accuracy during transition from idle to steady state running. The PAT estimation process is repeated about every 10 seconds.</p> |
