We demonstrate an adaptation
strategy for adjusting the stride period in a hexapedal running robot.
The robot is inspired by discoveries about the selfstabilizing properties
of insects and uses a sprawled posture, a bouncing alternatingtripod
gait, and passive compliance and damping in the limbs to achieve fast
(over four bodylengths per second), stable locomotion. The robot is controlled
by an openloop motor pattern that activates the legs at fixed intervals.
For maximum speed and efficiency, the stride period of the pattern should
be adjusted to match changes in terrain (e.g., slopes) or loading conditions
(e.g., carrying an object). An ideal adaptation strategy will complement
the design philosophy behind the robot and take advantage of the selfstabilizing
role of the mechanical system. In this paper we describe an adaptation
scheme based on measurements of ground contact timing obtained from binary
sensors on the robot's feet. We discuss the motivation for the approach,
putting it in the context of previous research on the dynamic properties
of running machines and bouncing multilegged animals, and we show the
results of the experiments.