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Predators

 

Fig. gif is a schematic of the intention generator of a predator, which is a specialized version of Fig. gif. To simplify matters, currently predators are not preyed upon by other predators, so they perform no predator detection, and escape, school, and mate intentions are disabled (F=0, L=0). Since predators cruise perpetually, the leave intention is also disabled.

   figure1612
Figure: The intention generator of a predator.

Generally potential prey are in less danger of being hunted when they are far away from the predator, or are in a school, or are behind the predator. A predator chases prey k if the cost of reaching it is minimal. This idea is based on the optimal foraging theory in ethology, which in its original form states that when an animal is feeding it makes its decisions in such a way that it will maximize its net rate of energy intake [Manning1979]. We model the cost of feeding on prey k as tex2html_wrap_inline3738 , where tex2html_wrap_inline3740 is the distance between the mouth of the predator and the center of prey k's body, tex2html_wrap_inline3744 if prey k is in a school of fishes, otherwise tex2html_wrap_inline3748 , and the angle tex2html_wrap_inline3750 (Fig. gif and Fig. gif) measures the turning cost. tex2html_wrap_inline3752 and tex2html_wrap_inline3754 are parameters that tune the contributions of tex2html_wrap_inline3756 and tex2html_wrap_inline3758 . We use tex2html_wrap_inline3760 and tex2html_wrap_inline3762 in our implementation of the focusser.

   figure1621
Figure: The angle tex2html_wrap_inline3758 .


next up previous contents
Next: Ingestion Up: Artificial Fish Types Previous: Artificial Fish Types
Xiaoyuan TuJanuary 1996