1、Lessons Learned Entry: 0279Lesson Info:a71 Lesson Number: 0279a71 Lesson Date: 1993-07-12a71 Submitting Organization: JPLa71 Submitted by: B. LarmanSubject: Exclusive use of Relative Spatial Positioning Commands for Mechanisms Abstract: The Mariner 69 Scan Platform and the Viking Orbiter Imaging Ins
2、trument Filter Wheel were operated with relative position stepping commands. In both cases, anomalies caused actual position to become different than the desired position. (This lesson largely duplicates #0405) Provide an explicit or absolute positioning capability in which the device can be command
3、ed to a specific position, allowing development of sequences in which periodic positioning to absolute locations can be executed. (This recommendation largely duplicates #0405 (D)Description of Driving Event: The Mariner 69 Scan Platform and the Viking Orbiter Imaging Instrument Filter Wheel were op
4、erated with relative position stepping commands. In both cases, anomalies caused actual position to become different than the desired position. Because each new position selection is based upon the previous position, all post-anomaly positions were incorrect until corrected via ground based interact
5、ion. This resulted in loss of science data.Additional Keyword(s): Design, OperationsLesson(s) Learned: The potential for getting out of step and unnecessarily losing data due to use of relative positioning exclusively is quite high.Recommendation(s): Provide an explicit or absolute positioning capab
6、ility in which the device can be commanded to a Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-specific position, allowing development of sequences in which periodic positioning to absolute locations can be executed.Evidence of Recurrence Control Ef
7、fectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1985-12-18a71 Approval Name: Carol Dumaina71 Approval Organization: 125-204a71 Approval Phone Number: 818-354-8242Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
