SELF TEST AUTOMATIC SELF CALIBRATE AND INTEGRITY MONITOR AS APPLIED TO AVIONIC EQUIPMENT.
Abstract
Self-test features in avionic equipment can be used either in flight or on the ground to assess proper system performance. Some self-test features are not only engineered to check performance of the system but also to facilitate precise adjustment of complex systems. In general, the self-test facility involves feeding a signal of known integrity into the input of the system and reading the answer output on the associated flight instrument. Feedback control to provide automatic error correction or self calibration is a logical extension of self test in avionic equipment. With automatic self calibration the test signal is continuously or periodically applied and if an error is detected it is automatically compensated for. Thus the effects of component aging or environmental changes which would tend to cause calibration errors are obviated insuring long service life of the system. A further extension of manual self test and automatic self calibrate is integrity monitor which in effect is continuous 'on-line' self test. The comparatively low confidence level of the warning circuits in avionic systems has been recognized by the industry for a number of years. At best, from a consideration of the circuit logic involved, the warning flags have done not much more than indicate the presence or absence of guidance signals. Safety of flight and especially of low approach and auto-land operations is intimately dependent upon the reliability and accuracy of the associated avionic sub-systems. Thus, if the output data of the guidance systems is for any reason unusable the warning circuits must be activated. Integrity monitor is the answer to this requirement. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 09, 1967
- Accession Number
- AD0664385