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Along with the continuous development of the research in the space exploration field, the precision rotation control
system is widely utilized in a lot of payloads of the satellites. It is stepping motor cooperating with reduction gear wheel
to accomplish the precision rotation in some pointing platforms of the camera used in the satellite. By contrast with that,
the approach of this paper could precisely control the rotation angle of the stepping motor without using reduction gear
wheel. Therefore, the size and the height of the instrument would be reduced base on simplifying the structural design.
Moreover, it reduces the cost to some extent. In this paper, it is adopted that the digital signal processor (DSP) controller
and bipolar constant current motor drive circuit UC3717 to make a high performance, high subdivision, miniature control
system come true, which is used to drive two-phase hybrid stepping motor. The methods are applied by the driver system
that sine cosine micro stepping and constant current chopper drive with a fixed chopper period. The driver system also
supplies the functions that involve subdivision selection, clockwise rotation or counter clockwise rotation control, and
over current or over voltage or under voltage or overload protection, and so on. The description in this paper also
includes the total schematic design, the approach to get current table in different subdivision levels, the current control
method in hybrid stepping motor, the way to reduce electro- magnetic interference (EMI) of the hybrid stepping motor.
And the total schematic design contains the DSP controller, the communication interface of the driver system, the design
of power driving circuit, the interface circuit between the electrical sources, the constant current chopper drive circuit for
the two-phase hybrid stepping motor. At last, it is verified by some experimental investigations that the control system
not only has miniature size, simplified system design, improved high frequency torque frequency characteristic and low
frequency stability, but also has enhanced adaptability and self-protection capability, improved accuracy of position
control and reliability of the driver. And the driver system is capable of dividing a full step into 256 micro steps. because
it is 1.8°that the angle of the full step of the two-phase hybrid stepping motor in the full step mode, therefore, it results in
51,200 steps per revolution (0.007º/step). So it could fulfill the demand of the precision rotation control system used in
some payloads of the satellites.
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