Design And Study On Automatic North-finding System In All Automatic Gyro-theodolite

Gyro-theodolite is an equipment which can direct the real north independently. It has played a very important role in national economy and national defense building. The gyro-theodolite need manual operate in our country. It is much slower and has a lower precision for different personnel operating. At present, the western developed countries have developed a fully automated, high-precision gyro-theodolite, in order to develop the fully automatic gyro-theodolite dependently, we have been designed a system of automatic north-finding which based on the JT-15-Gyrotheodolite. Ultimately, realized the gyro-theodolite fully automated.The system of automatic coarse north-finding designed by this paper can rotate the gyro-theodolite to the coarse north when it is in any position in horizontal. The precision is controlled in±30"and the time less than 1 min. After coarse North- finding, lower the sensitive components and make a precise north- finding. Last, raise it to turn off. The automatic rising-lowering institutions in which core of stepper motor has replace the traditional manual operation on the rising-lowering.In order to improve the automatic rising-lowering institutions and the rotary table's controlling precision. A stepper drive of eight fractionization has been designed by TA8435H. It is reliable and make the system more simple.The automatic reading system uses CCD to turn the cursor intensity into voltage and be acquisited by SCM. Then, SCM will calculate the value of cursor and sent it to computer for north-finding calculation. The SCM will receive the control commands from the PC also. In the advantages of plug and play and high-speed data transmission of USB2.0 interface. The USB2.0 which base on the chip of CY7C68013A has been designed for commiunication between the SCM and PC .Experimental results show that the all automated Gyro-theodolite can complete the North-finding without the manual intervention in condition of electrifing until gained the results. The precision of the equipment is 20", and the time can be control within 12 minutes。...