Design Of Inductosyn Angle Measuring System Based On DSP

In this paper, the high accuracy inductosyn angle measuring system is studied. Based on the basic principle of inductosyn, five kinds of signal processing methods are discussed. What is more, the errors caused by inductosyn body and errors caused by angle measuring signal processing circuit are analyzed. Besides, based on DSP, two-phase excitation one phase output phase pulse count inductosyn signal processing circuit is designed. Finally, using inductosyn and the signal processing circuit, a high accuracy inductosyn angle measuring system is built.First of all, based on the basic principle of inductosyn, the advantages and disadvantages of five kinds of signal processing methods are discussed and compared. The five kinds of signal processing methods are amplitude discriminator seeking arctangent method, amplitude discriminator seeking arcsine and arccosine method, amplitude discriminator tracking method, phase discriminator pulse count method and phase discriminator FFT method. According to analysis, compared with amplitude discriminator method, phase discriminator is easier and more accurate.Secondly, the errors of inductosyn angle measuring system are analyzed. The errors of inductosyn angle measuring system include the errors caused by inductosyn body and errors caused by angle measuring signal processing circuit. The errors caused by inductosyn body are analyzed, calculated and tested. The errors caused by inductosyn body include zero position error and subdivision error. The errors caused by angle measuring signal processing circuit are analyzed and calculated. According to analysis and calculation, rrrors caused by phase discriminator pulse count method signal processing circuit are smaller.Furthermore, the design method of one phase excitation two-phase output phase discriminator pulse count and two-phase excitation one phase output phase discriminator pulse count are compared. Two-phase excitation one phase output phase discriminator pulse count method has a simpler structure and higher accuracy. At last, the method of two-phase excitation one phase output phase discriminator pulse count is used to design angle measuring signal processing circuit.Besides, the two-phase excitation one phase output phase discriminator pulse count signal processing circuit is debugged. Based on inductosyn and signal processing circuit, a high accuracy inductosyn angle measuring system is built. The accuracy of the system is tested by the high accuracy air bearing turn table.Finally, this paper has analyzed the principle of inductosyn angle measuring system, signal processing methods and errors. Then a circuit board is made and an angle measuring system is built. It provides theoretical and experimental foundation for the study of inductosyn angle measuring system and has high practical value.