The initial ideas of the design process were developed in a brainstorming session between Mark and Andrew. The main areas of decision were narrowed down, then some general possible solutions were discussed. This process was recorded on A3 sheets (scannings of these sheets are available through the 'brain storming' links).
Have the same physical properties as an actual unicycle, e.g.. ~1m high
Recover from a reasonable disturbance
Capable of being used for longer periods of time without maintenance, e.g. battery charging
Self contained
Radio control
Be able to control heading and speed
Ability to idle
Use a natural method of physical control
Affordable (a robot of this size cannot be built on the CUED project budget (£200) alone, so sponsorship will be needed to help cover costs.
Aims identified:
Modern
Sleek
Well engineered
Robust
Easy to work with
Easy to maintain
Upgradeable
Bolted together for ease of maintenance
Economical e.g. steel or aluminium where possible
Protects and supports the electronics
Large enough for space not to be an issue
A tubular steel frame with additional sheets/brackets attached was decided for the general construction. An external cover would provide protection to the electronics and other internal components.
Specification:
Low backlash
Durable
Lightweight
Easy to manufacture
Adjustable
Affordable
Ideas
Low backlash Durable Lightweight Easy to manufacture Adjustable Affordable compact notes Chain - - + + + + + - not high speeds Belt - + + + - - not high speeds Gear Train + + - - - - + only short distances Direct Drive + + + + + + + - - + + low torque Bevel Gears - - - more position choices Drive Shaft + + - - transmits long distances Integral Gearing + + + + - - - - one bulky item to accommodate A gear train first stage with belt final drive or a drive shaft with bevel gears were taken forward as possible solutions.
Ideas
Fans
Gyroscopes
Tilting wheel
Moving weight
Flywheel
Combination
A flywheel and/or a moving weight were taken forward as possible steering mechanisms. The others were rejected because they weren't realistic or natural.
