A Group Of Ultrasonic Motor Driving System Design For Precision Turntable

Nowdays,the precision turntable have an increasingly wide application in aerospace, instrumentation, precision machinery and some other fields.It also palys an important role in some areas. Conventional turntable is usually driven by electromagnetic motors. and the coil and winding in electromagnetic motors would produce electromagnetic radiation while which will affect other controlling systems. The motor would also cause great fluctuation at the moment of when the motor starts or stops, which will have a significant impact on the measurement equipment on the turntable. Based on the above shortcomings of conventional motor-driven,we use ultrasonic motor to driven turntable instead of electromagnetic motors. The ultrasonic motors have excellent electromagnetic compatibility, power self-locking, fast response characteristics and can be used in precision turntable driving.In this paper, we choose sandwich structure according to the requirements of driving turntable and explicit basic components of the motor. We determine the structure of each components by analyzing its function. We determined the form of the excitation signal by analyzing the trajectories of the driving part. We analyzed the inputing way of excitation signal to make sure the that the driving parts could reach maximum amplitude and analyzed the working principle of the motor in an electrical period. We choose the appropriate materials of each components in accordance with their function. Determined an approximate length of the motor based on the first order longitudinal vibration of a single oscillator frequency, And analyzed the motor modal and harmonic response after two oscillators coupled with each other. Then determined the specific size of the motor according to the above results.Then designed the ultrasonic motor testing systems, tested the motor electrical parameters and working frequency and analyzed the motor performance. Designed the mechanical structure of the turntable testing system, built the experimental platform and the electrical control system. Analyzed the affection the assembly mode brings in. Tested speed, positioning accuracy of the turntable and analyzed the turntable systerm performance to verify the correctness of the driving control method.Testing some preference parameters of the motor. The working frequency of the motor is 40 KHz. In according with the the design requirements. Analyzing the relationship between frequency and speed, the relationship between voltage and speed and the relationship between speed and pre-stress. The maximum linear motion speed is 0.48m/s. Analyzing the turntable system, the radial rotating error and wobble error will be increased after the motor installing on the turntable. Given test on the speed of turntable, the maximum speed of the turntable is 15.8r/min which in line with the requirements of the turntable speed. Given test on the location noise of the turntable system, the location noise is too small and in line with expections.