Abstract: In order to realize the real time,non-contact and high precision measurement of the coating thickness of the small diameter solid rocket motor,a non-contact measurement system using laser displacement sensor is designed.The system is combined with the servo control system,the large length cantilever beam,the laser displacement sensor and the computer control system to ensure that the system can accurately measure the thickness of the coated layer in real time.It mainly introduces the structure of the system,the detection principle,the error analysis and some experimental analysis.The system has simple operation,high accuracy and good stability.It can realize the real-time and on-line,non-contact and high precision measurement of the thickness of the coating layer of the small diameter solid rocket motor.

Key words: laser non contact measurement, cantilever beam, servo control system, LabVIEW software