Title: Decentralized Control of a Hexapod Robot Using a Wireless Time Synchronized Network,
Abstract: Robots and control systems rely upon precise timing of sensors and actuators
in order to operate intelligently. We present a functioning hexapod robot that
walks with a dual tripod gait; each tripod is actuated using its own local
controller running on a separate wireless node. We compare and report the
results of operating the robot using two different decentralized control
schemes. With the first scheme, each controller relies on its own local clock
to generate control signals for the tripod it controls. With the second scheme,
each controller relies on a variable that is local to itself but that is
necessarily the same across controllers as a by-product of their host nodes
being part of a time synchronized IEEE802.15.4e network. The gait
synchronization error (time difference between what both controllers believe is
the start of the gait period) grows linearly when the controllers use their
local clocks, but remains bounded to within 112 microseconds when the
controllers use their nodes' time synchronized local variable.