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motion sensor on moving robot

PostPosted: Sun Dec 14, 2014 10:43 pm
by tseed
Hello everyone,

I would like to use a microwave motion sensor like this

Image

on a moving robot.

is it suitable? i afraid it will activate when the robot just start moving around.

Re: motion sensor on moving robot

PostPosted: Sun Dec 14, 2014 11:07 pm
by yonghui
What is the purpose of you wnat to put a sensor? I think the sensor u show is PIR sensor.

Re: motion sensor on moving robot

PostPosted: Sun Dec 14, 2014 11:51 pm
by tseed
thanks for the reply.

i took it from here,
http://www.lelong.com.my/motion-detect- ... Sale-P.htm

it says its a microwave sensor.

want to put it on a moving robot, where when i throw a ball at the robot, the motion sensor detect the ball and hit it. but the robot can move around. not static one.

tq.

Re: motion sensor on moving robot

PostPosted: Mon Dec 15, 2014 9:13 am
by ober
I doubt it is microwave sensor. As far as it look, it is PIR sensor. Check the wiki page for PIR sensor.

Anyway:
- PIR sensor cannot detect the ball direction even if it can detect the motion created by the ball (Most likely cannot).
- PIR will not provide the response for your robot to react and hit the ball.
- If the robot is moving around, how can the PIR sensor know the thing in front of it is moving because of mobile robot movement or the thing is moving? Human have a lot of sensors and powerful learning brain to do sensor fusion to identify moving item even while we are moving, not robot using a PIR sensor.
- Let me put it this way, do a static motion detection first, study how to hit the ball with static robot (not moving). Then take another step forward.

Re: motion sensor on moving robot

PostPosted: Mon Dec 15, 2014 7:21 pm
by tseed
thank you for the reply.

Yes, it does look like a PIR sensor but it should be a microwave motion sensor based on the spec.

As i know (from the interent), there are types of motion sensor for home
1) Using PIR
2) Using microwave pulses
3) Using both

http://www.safewise.com/resources/motion-sensor-guide

but i not really sure if it is suitable or not.

We already the make the robot hit the ball when it static by using lots of IR sensors. Somehow the IR sensor really hard to detect fast small ball. (we are using ping pong size ball). It can hit only when we throw it slowly.

Range finder laser sensor and LIDAR sensor are too expensive =='

To find alternative, I think motion sensor is ok. But after reading the reply i think not suitable.

Maybe you guys can suggest any alternative sensor that can detect small, fast object. we are still working on kinect.(got no experience on kinect so it takes times to develop) so meanwhile we are working on it, we are trying to find other alternative.

Tqvm.

Re: motion sensor on moving robot

PostPosted: Mon Dec 15, 2014 10:59 pm
by yonghui
If it is pir sensor. Confirm it won't work.since ball won't trigger pir. I think ir can work very very fast . then rise time is in micro seconds. Use a comparator to compare the reflected ir threshold. U can burst or tx at high current in short time to make receiver more sensitivitive too

Re: motion sensor on moving robot

PostPosted: Tue Dec 16, 2014 3:34 am
by tseed
thank you for the reply :)

Can u elaborate more on the 'burst at high current in short time" ? sorry im not really understand >.<'
put more current on tx is it?

btw i'm using Panasonic (SUNX) Photoelectric Sensor.
http://cytron.com.my/p-cx-422

tqvm

Re: motion sensor on moving robot

PostPosted: Tue Dec 16, 2014 9:40 pm
by yonghui
For this industrial sensor different story. What I meant was using the simplest ir transmitter and receiver photo diode