  Insects use visual cues to control their flight behaviours. By estimating the
angular velocity of the visual stimuli and regulating it to a constant value,
honeybees can perform a terrain following task which keeps the certain height
above the undulated ground. For mimicking this behaviour in a bio-plausible
computation structure, this paper presents a new angular velocity decoding
model based on the honeybee's behavioural experiments. The model consists of
three parts, the texture estimation layer for spatial information extraction,
the motion detection layer for temporal information extraction and the decoding
layer combining information from pervious layers to estimate the angular
velocity. Compared to previous methods on this field, the proposed model
produces responses largely independent of the spatial frequency and contrast in
grating experiments. The angular velocity based control scheme is proposed to
implement the model into a bee simulated by the game engine Unity. The perfect
terrain following above patterned ground and successfully flying over irregular
textured terrain show its potential for micro unmanned aerial vehicles' terrain
following.
