Real-time determination of fresh air quality in cylinder

The invention relates to a method for determining a fresh air quality characteristic variable in a cylinder of an internal combustion engine in a motor vehicle, comprising the following steps: identifying a cylinder in the end of an intake stroke or in the beginning of a compression stroke during the driving operation of the motor vehicle, determining a diagnostic time window, the diagnostic time window extends within a torque gap of the internal combustion engine after an intake valve of the identified cylinder is closed, a change in rotational speed of the internal combustion engine during the diagnostic time window is determined, and a fresh air quality characteristic variable in the identified cylinder is determined. 本发明涉及一种用于确定机动车中的内燃机的气缸中的新鲜空气质量特征参量的方法，该方法具有以下步骤：识别在机动车行驶运行期间处于进气冲程结束的或处于压缩冲程开始的气缸，确定诊断时间窗口，所述诊断时间窗口在所识别的气缸的进气门关闭之后在内燃机的扭矩空隙之内延伸，确定内燃机在诊断时间窗口期间的转速变化，确定所识别的气缸中的新鲜空气质量特征参量。