Frequency Optimal Control System Of Ultrasonic Biologic Process

With the in-depth research of power ultrasonic technology, the application scope of which has penetrated gradually into welding, grinding, biological treating and other industries. In this paper, to make up the shortcomings that follow the result which from group comparision test in existing methods, combinating with data acquisition (QAD) technology, serial communication technology, direct digital frequency synthesis (DDS) technology, we designed the frequency optimal control system of ultrasonic biologic process which based on ATMega16 and LabVIEW platform.The main research work of this paper includes: in the overall structure of the system design, considerating to the requirement and cost of system, analying the implementations of each functional module, showing the module type of the core components. In the signal detection module, designed the PLC detection subsystem which based on the core processor ATMega16, and achieved the signal collecting, converting, sending and resiving with the external circuit such as multi-channel signal selection, filter-amplifier and the converter of serial level. In sending, receiving and displaying module, this paper analyzed the communicated method between PC and PLC, and designed the PC subsystem based on LabVIEW platform, which included the module as serial port configurating, real-time signal displaying, change rate calculating and optimal strategy choosing and executing. To perform the optimal control strategy send by PC, in the optimal policy executing module, we designed the drive circuit for capacitive piezoelectric loads based on DDS technology and PWM control technology. To relized the closed loop control, this module contains the circuit such as invertor control signal generating, power protecting, inductance matching, frequency tracking and so on. Finally, we completed the system operating and debugging on the biological prcessing platform, and got the waveform which characterized the optimal strategy.The experimental result shows that the system can achieve the following functions such as: acquisition of multi-channal concentration signal in biological process, accurate and effective communication between PC and PLC, implementation of optimal control strategy and so on. This design improved the existing ultrasonic biological process effectively, increased automation of the process, and with good engneering value.