Study On Automatic North-finding Key Technique Of Gyroscope

Gyroscope which is an accurate measuring instrument to orient independently is widely used in the military, mapping, mine exploitation, and so on. Newly full automatic gyroscopes are monopolized by developed countries; domestic gyroscopes mainly manipulated by manpower with low measuring speed affect the measuring precision and could not meet the needs of modern technology. In order to make the full automatic gyroscopes in our country, the key technologies of full automatic gyroscope are researched in the dissertation.Microcomputer automatic measuring system of gyroscope is established, and automation of collecting cursor and north-finding is realized, which makes easy for the research of the north-finding arithmetic. Automatic rising-lowering sensitive components of the gyroscope is designed to automatically rise-low the sensitive components of the gyroscope instead of the traditional cam gear manipulated by manpower and intelligentized fault-handling method is applied in whole north-finding process. Half-baked period transit methods are studied, and a scheme of full automatic north-finding combining coarse north-finding by magnetic sensor with precise north-finding by gyroscope is proposed. A set of full automatic experiment equipment is constructed to confirm the rationality of the scheme.In combination with modern sensor and digital signal processing technology, linear motor controlled by the DSP(Digital Signal Processing) is adopted to automatically rise-low the sensitive components of the gyroscope instead of the traditional cam gear manipulated by manpower, which settles the bottleneck of full automation of gyroscope. The technology has been applied for a patent and is in checkup phase by far (applying number: 200610014750.X).Intelligent diagnosis is introduced to the north-finding of gyroscope at homeland for the first time. If the cursor sways or sway speed of north-finding exceeds the limit after the sensitive components of the gyroscope is lowed by motor, the sensitive components are raised automatically and lowed again, and then the threshold of alarm is set. In the process of data acquiring if the cursor sways or sway speed of north-finding exceeds the threshold, the gyroscope gives an alarm. The half-baked period transit methods and its applications in intelligent north-finding system are studied. In coarse north-finding, 5′north-finding precision can be reached and the measuring time is 10s using the acceleration curve to compute the balance position. 1/4 period measuring arithmetic is proposed creatively which only takes about 1/4~1/2 time of whole period method and could guarantee the precision of 30″. According to the research on the north-finding arithmetic, a scheme of full automation north-finding combining coarse north-finding by magnetic sensor with precise north-finding by gyroscope is proposed.Gyroscope digital measuring subsystem, sensitive components automatic rising and lowing subsystem, theodolite automatic controlling subsystem controlled by DSP and CPLD, combined with full automation north-finding scheme, make up of the whole-automation intelligent north-finding experimental system. The system could collect the moving curve of cursor automatically, operate automatically and intelligently, compute and display the north-finding results, and so on. JT-15 gyroscope is adopted as the experimental pattern, when north-finding precision is 8″, a whole automatic measuring period is less than 20min, and when north-finding precision is 30″, a whole automatic measuring period is less than 10min.