Testing System And Course Simulation Of Parachute Opening And Landing Shock

Parachute-opening shock, which always occurs in parachute opening and landing process is one of the most important parameter to estimate the performance of parachute. In allusion to this phenomenon, the article discusses the design of portable and intelligent parachute-opening shock measure system and the course simulation software based on the measured data.The whole measure system is composed of sensors, SCM, communication circuit and data location cell. A three-dimensional and orthogonal sensors system including three micro-silicon accelerometers has been designed in order to measure the opening and landing shock in multi-directions. In addition, the digital resistance and single computer are used to adjust the zero point of the output of sensors system. The ADuC812 SCM, produced by the Analog Device Corporation, is used in the system to reduce peripheral equipment and improve precision. In order to make users easy to debug and download programs, the system used RS-232 interface to communicate with the computer. CF card with True IDE mode is regarded as the data location chip. And we also adopt FAT16 file format as well as the technology of beforehand address space distributing to improve the efficiency in data location and convenience in data reading. The system's static features and dynamic features have been studied yet. It has been testified that the linearity, sensitivity, repetition, zero point excursion and time excursion are all in the requested error range. The measure speed is 0.2 ms/channel, the precision is 1/80 g/word, and the biggest capability is 1G bit. The system is a second order system, and its response frequency is 0~800Hz.According to the measured data, we have combined the parachute-opening shock curve and the real process, identified the key points, set up the analysis model and calculated the pose data and technical parameters of the parachute. The data processing module mainly carries out the data reading from CF card, filtering function, drawing the parachute-opening shock curve, identifying the extremum, exporting pictures as well as part magnifying function. The course simulation program is used to calculate parameters and simulate the process of the parachuteopening and landing.The measure system which provide important reference in parachute appraising, producing and instruction to parachute's material selecting, has been actually used well.