|Aesir by David Buckley
Loki December 2002|
Freya December 2002
Thor January 2003
Baldur September 2014
Ullr September 2019
The Aesir are a series of Biped Robots each using four servos, two servos per leg.
They explore the abilities of the different geometries obtainable using just two servos per leg and hence just
two degrees of freedom per leg.
These robots are much squatter than those previously built such as BigFoot and
Ambler but, because of the extra two servos, have far greater agility.
The goals of the Aesir project were for them to be able to play with a ball
and collect bricks. However that required more sensors and software than there was room for.
(The Aesir are a group of Norse gods.)
- Each of the Aesir is controlled by a PicAxe40x2 and powered by four AA cells.
- Except for Freya each has an Ultrasonic ranger.
- On the heads and legs there are forward facing high power orange LEDs for illuminating obstacles
which then can be detected by the black shrouded phototransitors next to them.
- There are ground contact switches on each foot for detecting table edges and whether there is secure footing.
- Except for Thor there are two tip sensors so they can tell if they are tipped forwards or backwards.
- Each can play sounds and Ring-tunes from their onboard speakers.
- They can store sixteen user inputted 16 character command strings in memory.
- There is a socket for extra memory so hundreds of commands could be stored.
- They can be instructed by commands from a Sony IR remote-control.
- Each can transmit IR commands to other robots or to a base station
- The full set of instructions can be sent serially as text over cable or a plugin radio module.
- Each has an on-board command-help file.
Equipment for each
- Power is from a 4AA cell battery
- The controller is a PicAxe40x2
- The Ultrasonic ranger is a HC-SRF04
- The orange LEDs are L-7113SEC-H 5mm Red/Orange 10000mcd supplied through 82 ohm resistors
- The phototransistors are TIL-78 with 100K load resistors
- The servos are standard size
- Frame material is 4mm birch ply
- On the rear is a 1.5mm coax power socket for an external power supply which automatically cuts out the battery, and there is a voltmeter with a 'press to test' switch to check the battery voltage.