Study On The Test Method Of Solar Array Drive Assembly Torque Characteristics

The solar panel is a key device providing energy supply to satellite in outer space.Solar panels use solar energy fully only when facing the sun directly, so the drivedevice is needed to control solar panels normals always parallel to the solar beam. Therotational inertia of solar panels is from a few kgm~2to tens of kgm~2, so a sufficientdriving torque is needed. It is necessary to test the solar array drive assembly torquecharacteristics.Solar array drive assembly is composed by stepper motor, conductive ring,angular position sensor, mechanism body and drive circuit, which torquecharacteristics include the electromagnetic torque of stepper motor and the frictiontorque in components mainly. The friction torque characteristics are constant when inthe static and uniform conditions, so the torque characteristics variation of solar arraydrive assembly and steppe r motor are similar. Considered the two-phase hybridstepper motor as tested prototype in laboratory conditions, test methods of the solararray drive assembly torque characteristics is studied.The torque characteristics mathematics model of the solar array drive assembly isresearched, and the electromagnetic torque mode l of stepper motor is summarized. Anovel method is proposed according to the feature of torque characteristics. It is basedon an idea of the torque ba lance, with a combination of torque-angle transmissionmechanism to test the torque characteristics continuously. The torque characteristicsMeasurement system is designed based on the method.In the hardware design of the system, it uses computer as processing platform.The test platform is build with precision torque sensor, angle encoder, data acquisitioncard and DC torque motor. The torque signal and the angle signal processing circuitare designed to improve the anti-noise performance of the test signal, the controllerreference signa l constitute circuit in different modes is designed to provide differentcontrol mode for different test parameters, the hardware protection circuit is designedto improve the safety and reliability of the system. In the software design, the modularmethod makes it easy to expa nd its functions. It includes three parts: command andcontrol module, measurement data acquisition module, the data processing andanalysis module. The integrated use of data communication technology through thePCI and RS232, multi-threading and thread synchronization technology, memorymapping technology, database operation technology based on ADO and visual optimization technique based on SkinMagic, ensures the software’s high efficientoperation and simple, friendly operation interface.A two-phase hybrid stepping motor is used as a tested prototype to test the torquecharacteristic. The results show that the system can test the prototype’s torquecharacteristic stably and reliably. After System debug completed, the solar array driveassembly’s torque characteristic is tested repeatedly in the work field. Results showthat the system can realize the testing of three torque characteristic of the solar arraydrive assembly.