Research On Driving And Controlling System Of Linear Ultrasonic Motor Based On DSP/FPGA

The source of this topic is a key project of National Key Basic Research Development Program(973Program)(Fund number:2011CB707602) and the National Natural Science Foundation (Fundnumber:50975136，51275229).In order to improve level of advanced manufacturing technology, especially the manufacture ofprecision parts equipment of China, a precision positioning platform based on linear ultrasonic motoris increasingly showing its importance. The principle of linear ultrasonic motor is based on the inversepiezoelectric effect of piezoelectric ceramics,which is different from the conventional electromagneticmotor.It can make linear motion without any convert agency,with the advantages of no motionconversion mechanism, simple structure, quick response, self-locking when power off and highresolution.Therefore, it can be used as a drive unit of high-precision positioning motion platform,substituting the original electromagnetic motor.However, in order to maximize the advantages of sucha positioning platform, the rearch and development of a suitable linear ultrasonic motor driving andcontrolling system is the most important.In this paper, the driving and controlling system of linear ultrasonic motor is studied.Theresearch object is V-shape ultrasonic motor with double amplifier poles and the experimental carrier isthree-dimensional motion platform based on linear ultrasonic motor.The drive controller cansimultaneouslybe used for the effective control of the motor: amplitude modulation governor,frequency modulation governor and the phase modulation governor.The hardware is consist of two parts,one is the drive board based on DSP/FPGA,another is thecontrol board based on amplifier/booster.The core of the control board is TI’s DSP(Chipsnumber:TMS320F28335),and the Altera’s FPGA(Chips number:EP2C20) and other functionalmodules are peripherals.The grating feedback the motor’s speed and position information toDSP.Control part,drive part and feedback part constitute an entire closed-loop control system.As forthe software,the whole control is launched by PC. When DSP receives the control commands, it willdo algorithm analysising and passe the control word to FPGA.FPGA will produce a correspondingdrive signal to drive the motor.After completing the design of the drive controller, some experimental study of the cell punctureis carried out.First, the characteristics of the motor start-up phase by different drive signal isanalyzed.Then the stability of the motor in the fixed gain PID and variable gain PID algorithm is studied.Finally,the drift problem of the linear motor id solved.