Abstract: Devices and techniques are generally described for on-time performance impact evaluation. In some examples, first flight plan data that includes a plurality of scheduled air-based routes may be determined. A first route of the plurality of scheduled air-based routes may be selected for a first package. First scan data related to the first package may be received. A first slack time associated with the first package on a first flight of the first route may be determined based at least in part on the first scan data. The first package being assigned to the first route may be evaluated based at least in part on the first slack time.

Abstract: A strapdown inertial navigation heave measurement method using multiple low-pass filter units includes: firstly, collecting data of a gyroscope and an accelerometer by a system, obtaining attitude information of a carrier by using initial alignment, and then, obtaining a relationship matrix between a body coordinate system and a geographic coordinate system by using the attitude information; obtaining a relationship matrix between the geographic coordinate system and a reference coordinate system according to a geographic position, and obtaining a rough vertical acceleration by using a direction cosine matrix, output information of the accelerometer and gravity information; then, filtering out low-frequency signals by using a first filter unit and integration to obtain a relatively accurate velocity signal; and furthermore, enabling the vertical acceleration to be subjected to a second filter unit and integration to obtain an accurate heave displacement.

Abstract: The disclosure discloses a strapdown inertial navigation heave measurement method using multiple low-pass filter units, including: firstly, collecting data of a gyroscope and an accelerometer by a system, obtaining attitude information of a carrier by using initial alignment, and then, obtaining a relationship matrix between a body coordinate system and a geographic coordinate system by using the attitude information; obtaining a relationship matrix between the geographic coordinate system and a semi-fixed coordinate system according to a geographic position, and obtaining a rough vertical acceleration by using a direction cosine matrix, output information of the accelerometer and gravity information; then, filtering out low-frequency signals by using a double-filter unit and one integral link to obtain a relatively accurate velocity signal; and furthermore, enabling the vertical acceleration to be subjected to a triple-filter unit and two integral links to obtain an accurate heave displacement.