SUMMARY OF INFRARED FALL DETECTOR PROJECTOR

The whole project was done within five weeks, by Tianqiong Du, Guotao Dong, Hanyi Fei and Yuxiao Fang, and supervised by Dr.Yan. we met different problems during this period, such as connection problem, design problem and signal process problems. By brainstorm and dedication, we solved various problems and finally finish this project satisfying result.

Through correcting the design circuit for several times, the final system contains one sensor RE200B-P, two operational amplifiers used to amplify the signal voltage, one operational amplifier used as analog to digital converter and an Arduino board used to idealize the signal, a PC used to monitor the motion situation.

The final result is shown in the video below: when there is no fall motion occurs, the buzzer stay silent, when there is a fall motion happens, the buzzer beats. and the effective detection range of this detector is within 1 meter, the video can be found in our week 5 blog.

There are also some limitations of this infrared fall detector. if it is turned on too long, it goes out of order; and its detection range is not wide enough. this limitations might be solved in further research.

28th FEB - The Sixth Lab - Test different movement form

This lab time, we combined the 'Arduino' board to control the signal. As I mentioned in the last blog , the signal is not stable when sensor detects movement. 'Arduino' board can completely solve this problem. This is code.

Figure 1

'a' and 'b' control the upper circuit and lower circuit delay time respectively. Meanwhile, 'm' and 'n' control the voltage of upper circuit and lower circuit respectively. When delay time is greater than 30, the generated low voltage is in the steady state which means no movement pass that sensor. Conversely, if delay time is less than 30, this low voltage is in the unstable high voltage range which means it can be ignored. Figure 2 shows the relevant range. 

Figure 2

After that, fall detection can be detected.