A Position Control System Of A Platform Based On Linear CCD

Platform position control means that the platform position is relatively stable under the reference system.Its performance is directly related to the reliability and credibility of optical observation,experimental precision and the device installed on the platform.In the paper,a platform position control system based on linear CCD is designed and set up.The system includes optical measuring path,mechanical device,signal acquisition and processing circuits,user software and so on.The main works include:1.Design and set up the optical measuring path.The liner array CCD is used to obtain the light spot signal which contains the position of the platform.A mechanical structure is designed and manufactured,which assembles all the components in the optical path together.2.The output analog signal of the linear CCD is analyzed,and low-pass filter circuit is used to process the signal.After that,the signal is sampled to digital signal by the data acquisition card in the system.The digital signal is input onto the computer.Use the threshold method to obtain the spot in the linear CCD,which indicates the position of the platform.When the platform position changes,the piezoelectric ceramic is controlled to move to achieve the platform back to the original position according to the measured position change.After that,the feedback control is realized.The data processing and feedback control are controlled by the user software.3.The error and response time of the system is measured.The result is that the relative error of the system position was 2.88%,and the response time of the system was about 21ms.Therefore,the system can be used for real-time platform position feedback control.In addition,the source of system error is also analyzed.