System and method for detecting and isolating faults in pressure sensing of flush air data system (FADS)

摘要

A system and method for detecting and isolating faults in pressure ports (2) and pressure transducers (3) of a pressure sensing system are disclosed. The system comprises a set of pressure ports (2) flushed to a nose cap (1) of a space vehicle in crucifix form. Three pressure transducers (3) are connected to each pressure port (2) through pneumatic tubes (4) for measuring surface pressure from the pressure ports (2). Separate power supplying units (7, 8, 9) are connected to the three pressure transducers (3) for powering the pressure transducers (3) at each pressure port (2). A processing unit (10) is configured to acquire voltage inputs corresponding to the measured surface pressure from the pressure transducers (3). The processing unit (10) executes one or more levels of fault checking to detect and isolate pressure transducer failures and blockage of the pressure ports (2) based on the voltage inputs. Hence, it is possible to enhance the accuracy and reliability of the pressure estimation of the FADS, cushion pressure.

主权项

1. A method for detecting and isolating faults in pressure ports and pressure transducers of a pressure sensing system, comprising:
distinguishing pressure port blockage failures from pressure transducer failures by cross comparison of surface pressures measured at a plurality of pressure ports; determining whether the measured surface pressures lie within a desired range to a coarse level at a specific instant of flight phase; checking constant pressure and rate on the measured surface pressures to identify full or partial blockage in said plurality of pressure ports and sudden failures on a plurality of pressure transducers; generating one or more structured sets of angle of attack and sideslip angle estimates from predefined combinations of said plurality of pressure ports lying along a vertical and horizontal meridians of a vehicle nose cap; and detecting and isolating the faults in said plurality of pressure ports and said plurality of pressure transducers in the vertical and horizontal meridians based on said one or more structured sets of angle of attack and sideslip angle estimates.