New lower price for Axon II ($78) and Axon Mote ($58).
0 Members and 1 Guest are viewing this topic.
sharp ir range finders have their own modulation built in in for optimal performance
I understand that Sharp IRs are optimized, but can they really work in sunlight ?
This my first post - so I hope this is helpful.there's a few things you could do to mitigate the effects of the IR outside these three are increasing in difficulty and cost:1.) you can put the sensor in a deep cavity (~2-4") with black absorbing material e.g. foam in a camera case surrounding it. this reduces scattering from the surroundings that would add noise to the detectors. this is highly fov constraining however. but you can have a linear array to increase this. the downside is that the black material in the sun will eventually heat and saturate the sensor.2.) the IR from outside is also going to be because of the temperature differentials as well as the material backscatter in IR. you can test this as airman seems to be trying out; but all materials will have some backscatter and thermal mass to them. lighter materials will have different signatures than heavy materials. also color and reflectivity matter, so these characteristics will change the behavior from room temperature dynamics. This is because a lot of the sensors are likely using black or gray body assumptions for the temperature response unless they have multiple IR colors. so a near field background calibration is necessary often. this means you have a control that you look at at a controlled temperature and reflectivity and then you can try and compare those readings to what your sensor is observing in the real world. [cheap way is to possibly put this in a box in a specific area of the field of regard of the sensor and take some occasional measurements/cals]. adding a color sensor & photodetector could help.3.) outdoors can have a lot of particulates and aerosols and more variation in water vapor than indoors. avoiding these variations is generally a good idea, or having active monitoring of these conditions to eliminate the biases to your readings. this again more advanced and will require a lot more sensors and more $.basic rule is to eliminate the random backscatter, control or observe the thermal properties of the bot's sensors, calibrate out the noise, and rule out false alarms with other sensors.
if sharp ir causes so much problem ,then why use it ,why not ultrasonic instead
i dunno how the heck people map with ultrasonici read about it and it has a 30 degree beamthis thing is pretty unprecise