I'm working on an idea and I thought I ask here for suggestions for how to solve a problem.· I'm looking to build a bot that will follow a person, maintaining a configurable distance.· How might one accomplish such a task?
What kind of distance are you talking about? What's the environment? There was a thread here a few weeks ago about a bot that could react to a summons from somewhere in a house. We discussed possibly having IR transponders in each room, linked from room to room. The summons would be by IR and would carry the approximate location. Once in the room, the bot would look for an IR beacon attached to the person and follow that.
An IR beacon is probably the best way to have a following bot. It would be uniquely modulated, so several different individuals could have different beacons. It's more reliable in sunlight and interior lighting because of the modulation. By having a narrow beamwidth sensor on a servo, the bot could look for the best signal. It could also use something like a PING ultrasonic distance sensor to locate other objects in the room, and to help track the person being followed once the bot is close enough.
The distance we are discussing is a few feet (2-10). The environment would be indoors or outdoors perhaps over rough-ish terrain. The bot would not need to locate the target to follow initially as the target person would approach the bot and signal it to initiate & terminate to following behaviour. My initial idea included a belt mounted IR beacon/controller that served to provide a point of reference for the bot to follow and allowed the user to toggle the following functionality on and off and I too thought about using an ultrasonic ranger. I've done a few experiments with that though and ran into a few problems. The ultrasonic ranger did not perform well outdoors. For example, If the target walked up a slight incline, the ultrasonic ranger read the slope or underbrush instead of the person as its ranging target. It's beam pattern was too broad and generalized. The IR beacon was easily blocked by movements of the user, brush or lost as the target ascended inclines. I was thinking some sort of traingulation scheme might be a better ranging solution, perhaps using an RF transmitter as the beacon & controller. Maybe the interference with the IR beacon could be acceptable if the ranging weren't so glitchy.
It might be wise to break that huge paragraph down into a few separate thoughts or questions, as follows:
Environment and Distance:
The distance we are discussing is a few feet (2-10). The environment would be indoors or outdoors perhaps over rough-ish terrain.
Goals:
The bot would not need to locate the target to follow initially as the target person would approach the bot and signal it to initiate & terminate to following behaviour. My initial idea included a belt mounted IR beacon/controller that served to provide a point of reference for the bot to follow and allowed the user to toggle the following functionality on and off and I too thought about using an ultrasonic ranger. I've done a few experiments with that though and ran into a few problems. The ultrasonic ranger did not perform well outdoors.
Example of Use:
For example, If the target walked up a slight incline, the ultrasonic ranger read the slope or underbrush instead of the person as its ranging target. It's beam pattern was too broad and generalized.
Localization:
The IR beacon was easily blocked by movements of the user, brush or lost as the target ascended inclines. I was thinking some sort of traingulation scheme might be a better ranging solution, perhaps using an RF transmitter as the beacon & controller. Maybe the interference with the IR beacon could be acceptable if the ranging weren't so glitchy.
Comments
An IR beacon is probably the best way to have a following bot. It would be uniquely modulated, so several different individuals could have different beacons. It's more reliable in sunlight and interior lighting because of the modulation. By having a narrow beamwidth sensor on a servo, the bot could look for the best signal. It could also use something like a PING ultrasonic distance sensor to locate other objects in the room, and to help track the person being followed once the bot is close enough.
It might be wise to break that huge paragraph down into a few separate thoughts or questions, as follows:
Environment and Distance:
The distance we are discussing is a few feet (2-10). The environment would be indoors or outdoors perhaps over rough-ish terrain.
Goals:
The bot would not need to locate the target to follow initially as the target person would approach the bot and signal it to initiate & terminate to following behaviour. My initial idea included a belt mounted IR beacon/controller that served to provide a point of reference for the bot to follow and allowed the user to toggle the following functionality on and off and I too thought about using an ultrasonic ranger. I've done a few experiments with that though and ran into a few problems. The ultrasonic ranger did not perform well outdoors.
Example of Use:
For example, If the target walked up a slight incline, the ultrasonic ranger read the slope or underbrush instead of the person as its ranging target. It's beam pattern was too broad and generalized.
Localization:
The IR beacon was easily blocked by movements of the user, brush or lost as the target ascended inclines. I was thinking some sort of traingulation scheme might be a better ranging solution, perhaps using an RF transmitter as the beacon & controller. Maybe the interference with the IR beacon could be acceptable if the ranging weren't so glitchy.
Regards,
Bruce Bates
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