Development Of Thrust Generator For Small-force Dynamic Testing Of Rocket Motor

With the development of modern science and technology, sensing and testing system is increasingly used in dynamic testing areas. In a long past period of time, the measurement of dynamic force was often used the method of "superscript used static" so as to influence the accuracy of dynamic testing. The dynamic calibration is imperative to know the dynamic performance of sensing and testing system accurately and completely. At present, domestic and overseas research is focused on static calibration of the sensors, but the less study of dynamic calibration. One of the main reasons is the limit of the experiment equipment, lacking of specialized equipment used in the dynamic calibration. This paper is to develop a device of dynamic calibration of testing system to make up for a deficiency of the "static superscript used" style is inadequate. So the dynamic characteristics of testing system can be evaluated accurately.The dynamic calibration of this testing system is demanded that dynamic calibration should be performed under rated dynamic force generated by the real engine. Because the coil in the magnetic field is subjected to electromagnetic force, electromagnetic vibrator is used as actuation component matching the corresponding signal generator and the power amplifier to achieve the required dynamic-force signal. Through theoretical analysis and simulation of Multisim, a method is presented that the influence of inductance of vibrator on output signal is overcome. The voltage of non-standard trapezoid with peak is used as the excitation signal of vibrator to generate the standard trapezoidal dynamic-force signal by vibrator. AT89S51 is acted as the core of hardware, supported by D / A converters and other digital components, and the corresponding procedures are programmed so that required excitation signal can be generated by vibrator.The experimental results confirm the design principle of the device generating desired trapezoidal dynamic force required by the dynamic calibration for the thrust testing system of engine. The trapezoidal dynamic-force signal obtained by experiment meets the project requirements. The research provides a good foundation for thrust testing system of engine.