If a school is detected by a predator, the odds of being eaten is still less for an individual fish.
Although it might seem that a school made of thousands (or millions) of fishes would be highly visible, the probability of detection of a school is not larger than a single isolated fish. The reason has to do with the optical character of the medium. "Contrast" is highly important for distinguishing an object from the background. Since scattering and absorption of light in water greatly reduces the contrast, maximum
visibility distance is 200 m., even in exceptionally clean waters. In the open ocean a predator's chance of finding a school of one thousand fish is slightly greater than its chance of finding one fish.
Achieving a regular distance between individuals along a parabola is difficult. Because distance and angle between each pair are different.
Preferred distance and preferred angle are statistical values since the spatial relations among fishes change constantly as the school changes its direction and speed.
Lateral line: An organ sensitive to displacement of water.
Pheromone: A chemical substance that is produced by an animal and serves especially as a stimulus to other individuals of the same species for one or more behavioral responses.
Here is an example decomposition of a mobile robot control system based on task achieving behaviors:
Squirt weighs about 50 gr. and is about 5/4 cubic inches in volume. It has an 8-bit onboard microprocessor, power supply, three sensors and a propulsion system.
Webster defines 'schema' as a mental codification of experience that includes a particular organized way of perceiving cognitively and responding to a complex situation or set of stimuli.
Note that this requirement on total number of robots is a result of our definition of fv. As an alternative method, beacons can broadcast the desired number of robot for a particular pallet.
For the time being we assume that all agents can detect all beacons, and also all firsts can "see" other firsts.
'Detection map' shows whether a first agent can detect other firsts or not. See screen snapshots given in Figure B.6 of the Appendix.
Here is a definition of semaphores in operating systems theory: A semaphore, first defined by Dijkstra in 1965, is a protected variable whose value can be accessed and altered only by certain operations.
Source sharing problem: An agent, before signaling its arrival to the beacon must assure that the beacon is not busy receiving another arrival signal.
A behavioral module is actually a subroutine that monitors specific inputs/variables, and initiates some other subroutine (or behavioral module) when necessary.
Number of nodes is number of agents linking the robot and the beacon. The moving-toward-goal signal is actually the same as the moving-toward-robot; the only difference is the data -number of nodes- embedded in the signal.
Achieving a situation where all vertical forces are the same does not necessarily mean that the most stable configuration is achieved. In both situations shown below, the vertical forces sensed by robots are the same, but the configuration in (a) is more stable.
One straightforward solution to obtain a more stable situation is to force robots to move away from the closest teammate (with the use of proximity sensors) while staying under the pallet. If there is a need for a
decision method to obtain the most stable configuration, devising an algorithm for this purpose will be extremely difficult. Besides the simulation difficulties (because of the non-invertibility of the moment matrix for cases with more than three robots), the algorithm must have adaptive properties due to the "fuzzy" character of the problem.
The "significance" of the changes is related to the parameters which define the allowable force range, and to mapping function.
A sensor is active if it emits an information which has to interact with the environment before being analysed.