Polypod Modules

Polypod is made up of two types of modules called Segments and Nodes.

Segments are two degree of freedom parallel mechanisms composed of 10 links. The kinematics of the resulting mechanism is similar to two prismatic joints joined together by a revolute joint where the prismatic joints are constrained to have the same length.

Each segment module contains all the components to be a stand-alone robot in itself (except for power):

• Computation: Motorola XC68HC11E2 (generously donated by Motorola)
• Actuation: Two small DC motors with lead screw transmission
• Sensing:
  • IR proximity sensing
  • crude force/torque sensing using IR
  • joint angle position sensing (potentiometers)
• Inter-module Communication: Global synchronous communication (Motorola SPI with RS485 drivers) between 68HC11's plus local IR communication between adjacent modules.

Power is supplied by the second type of modules called Nodes. Nodes are rigid cube shaped modules roughly 2"x2"x2" with 6 connection ports whose main purpose is to hold gel-cel batteries and to allow for non-serial chain robots.

By the time I graduated in Dec. 1994 I had 11 modules total. Here are some photos(~200K)of the physical robot.