Study And Implementation Of Power Ultrasonic Driving System Based On Adaptive Control Technology

Power ultrasonic technology is an application technology that utilizes the energy characteristics of ultrasonic waves to change the material state and properties of the load.It is an important research direction in ultrasonics and is widely used in aerospace,marine,industrial production and bioengineering.The power ultrasonic drive system is the core component of various types of ultrasonic equipment,which directly affects the performance and service life of the ultrasonic equipment.In industry and life,ultrasonic cleaning is widely used because of its convenient use,high cleaning efficiency and good effect.For the development scale,this paper studies the methods of intelligent ultrasonic cleaning,such as impedance matching and adaptive control of power ultrasonic drive system.The main research contents and completed work include:1.Based on the research status at home and abroad and related technical means,the key technologies of power ultrasonic drive system are analyzed.According to the requirement of the system,the overall scheme of the power ultrasonic driving system is designed.2.Aiming at the problem that impedance matching fails with the change of load,an improved LC matching circuit is designed based on the equivalent model of LC matching ultrasonic transducer.Based on the resonant frequency of the matching device,the model is quantitatively analyzed to obtain the optimal matching parameters of LC.The simulation results show that the matching method can effectively improve the stability of output power of power ultrasonic driving system when the transducer works at series resonant frequency.3.Aiming at the problem of resonant frequency drift of transducer,a high precision and fast tracking method of series resonant frequency of transducer based on double current feedback is proposed.The series resonant frequency of the transducer is determined by the effective value of the transducer and the matched capacitive current and the phase difference between them.The high precision and fast tracking of the series resonant frequency of the transducer is realized by combining the frequency sweeping method of dichotomy.The series resonant frequency of the transducer can be accurately tracked under the condition of mismatch and load variation.4.The driving signal frequency and the center frequency of the switched capacitor filter are jointly controlled to realize the real-time tracking of the series resonant frequency of the transducer.The active power of the system is obtained directly by using hardware multiplier,and the constant output control of the active power of the system is realized by using the power control method based on adaptive single neuron PID.5.The experimental platform of the system is built.The experimental results show that the improved LC matching method can improve the output power of the system and effectively withstand the fluctuation of load.The high precision and fast tracking method of transducer series resonant frequency based on double current feedback can complete frequency tracking within 100 ms and the frequency tracking accuracy can reach 20 Hz.The adaptive power control method can achieve constant active power output,and the power output deviation can be less than 10% for the change of load.