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Technical Design
   TECHNICAL DESIGN: Quick Facts
How long does it take to map?
How many mappers do we need?
How frequently the robots break?
How many robots do you need for the final demo?
How large is the area for demo-II?
How long does it take to charge the robot?
How long does it take to discharge the robot?
How many can use at any given time?
How much power does the computer use?
What type of batteries do you have ?
  Mapping
We've mapped manually (meaning 3 times faster than in autonomous mode) about 466 m2 (of hallway only!) in 20min.
We are estimating that the same area will take about 60 min if mapped automatically. Assuming that we need to map about 10000 m2 for the final demo, a single robot needs 21 hours and 30 minutes.
Since we would like the mapping tasks to be done in less than 2 hours, we should have around 20 mappers to complete the task in less than 2 hours.
This map was produced in 20min using a single robot in manual control. The mapped area is 466 m2.
Q: How long does it take to map?
A: For 466 m2, 60 minutes, 10000 m2, 21 hours

Q: How many mappers do we need?
A: About 20 to keep the mapping task under 2 hours to complete.
Q: How large is the demo-II area ?
A building
A: The complete arena contains 52 offices and has an area of 2790 m2 or 25,110 sq/ft
  Breaking:
Q: How frequently do the robots break?
A:  Here are some data from our first demo:
  • We had 5 Pioneer 2 (AT or DX), we broke 2 out of the 5. One motor burned (probably due to our carpet) on one of them and the other one had some electrical issues. But a third one did start to make some squeaky noise after intensive use. To be conservative, the break ratio will be 30% for this model.
  • We had 20 Amigobots, we broke only 2. One had a bad connection, so sometimes it lost power completely. The other one had a computer issue that disappeared the day after the demo (lazy one). The break ratio is 0.1%.

Q: How many robots do you need for the final demo?
A: Based on the number of mappers needed for the mapping tasks (see previous question):
  • We would need about 26 mappers. 20 for the task and 6 as spare.
  • We will have 92 amigobots so we should have about 82 running.
  Battery Life
We have collected some data about the discharge of the Amigobot, the mappers have replaceable batteries so if we can have enough batteries we should be able to swap them. The Amigobots have no replaceable batteries so we need to find out how many we can use at any given time in order to maintain the system in a stable state.

Discharge of a robot with acid/lead batteries in search mode:
Discharge of the same robot, in stationary mode, tracking human:
Discharge of a robot with NiCd batteries in search mode:
Q: How long does it take to recharge the robot ?
A: About 5 hours for the NiMh battery we have.

Q: How long does it take to discharge the robot?
A: When searching they use their battery in 65 min. When stationary for human tracking, they use their battery in 220 min.

Q: How many robots can we use at any given time ?
A: We don't know that yet !

Q: What type of batteries do you have ?
A: We have so far 3 types of battery:
  • PowerSonic PS-1230. It's a 12V 3Ah battery.
  • Ni-MH 12V, 9Ah D-Cell battery.
  • A new improved version Ni-MH 12V, 13Ah F-Cell type battery.

Q:How much power does the computer use?
A: We have measured that the new VIA M9000 with harddrive running (without wireless and camera) use on average 2.3 A (varying between 2.1A to 2.5A).

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