Dynamic Test of Rocket’s Sensor and Communication Subsystems

Abstract

This paper presents the test results of hardware and software for sensor and communication subsystems of Defence Technology Institute’s guided rocket. The whole system was initially tested on a smaller and less capable weather-modification rocket platform. Performance of two Frequency Hopping Spread Spectrum COTS telemetry modules were compared and verified for their suitability in harsh environmental operation, especially their sensors and communication electronics. Telemetry data from the Inertial Measurement Unit (IMU) was logged and the Inertial Navigation System (INS) data was calculated from guidance processor before being transmitted wirelessly to a ground station. These empirical data were recorded for further analysis and compared against those from the simulation as part of rocket guidance system development.

It was found that both COTS telemetry modules had comparable performance and could acquire all data through most of the flights. The recorded IMU inflight data, the acceleration and the angular velocity of the same instance, showed similar trends to the simulated values and some saturation were found at the upper range limit of the component, i.e. 30g for the acceleration and 4000 degrees/sec for the angular velocity. After some calculations of the measured data, the calculated values of the displacement and various angle data were found relatively closed to simulated values. However, at later time, the errors were escalated due to the fact that the fixation of the sensors were not well centered and the sensors were not thoroughly calibrated, which led to incorrect calculation at the later phase.