Developing Accelerometer Based Vibration Detection System to Evaluate The Influence of Hand Motion on Movement of Rifle Muzzle

Rifle vibration has been known to influence shooting precision. One of the most influential factors affecting rifle vibration is hand tremor. In this study, we developed an accelerometer-based hand motion detector. The system was developed using ATmega 2560, which controlled three ADXL345 accelerometer sensors. The sensors were placed on the left hand, right hand, and rifle muzzle. The system was connected to a personal computer via type A to type B universal serial bus. A python-based program was used to record and save the data as a coma separated value file. The system was evaluated by measuring the hand tremor of novice and shooters with experience. The evaluation was conducted by requesting the shooter move in the sequential free position, ready-low position, and aim position. The recording was conducted from the free position until the shooter's aim was off target. A Laser pointer was used to evaluate the aim. The results show that the device can record the hand movement from free posture to aim position. From the device data, we observed that the novice participant spent 13×102 ms changing the free position toward the ready-low position, 8×102 ms for the ready-low to aim position, and 28×102 ms to stabilize the aim. The novice was observed to stand in the aiming position for 1,651×102 ms before the aim was off target, while the experienced participant was capable holds the position up to 2731×102 ms. Furthermore, the experienced participant only needed about 6×102 ms to move their position from free to ready-low and 4×102 ms for ready-low to stabilize their aim. The device also shows the difference in rifle aim precision between novice and experienced participants. It can be concluded that the device works well to record the rifle movement due to the shooter's hand motion.