Swarm Intelligence

Submitted by:-Nitesh Bichwani(02224302013)

CONTENTS Introduction

What is a Swarm Intelligence (SI)? Examples from nature

Real world examples Honey Bee Wasps Ant

Inspiration from Nature Natural navigation Natural clustering Bird Flocking Ant Colony Optimization

What is Swarm Intelligence (SI)?

• Swarm intelligence (SI) is an artificial intelligence technique based around the study of collective behavior in decentralized, self-organized systems.

• Introduced by Gerardo Beni and Jing Wang in 1989.

• Typically made up of a population of simple agents.

INTRODUCTION

Examples in natural systems of SI include : Ant colonies, bee beehive , fish schooling , bird flocking , bacterial growth,  and microbial intelligence.

Fish Schooling

Bird Flocking

Bee Beehive

Ant Colonies

Real world examples

1. Honey Bee•Colony cooperation

•Regulate hive temperature

•Efficiency via Specialization: division of labor in the colony

•Communication : Food sources are exploited according to quality and distance from the hive.

•Pulp foragers, water foragers & builders•Complex nests

Horizontal columnsProtective coveringCentral entrance hole

2. Wasps

•Organizing highways to and from their foraging sites by leaving pheromone trails

•Form chains from their own bodies to create a bridge to pull and hold leafs together with silk

•Division of labor between major and minor ants

3. Ants

Inspiration from Nature

1. Natural Navigation

Food

Ants (blind) navigate from nest to food source

Shortest path is discovered via pheromone trails

each ant moves at random, probabilistically

pheromone is deposited on path

ants detect lead ant’s path, inclined to follow, i.e.,

more pheromone on path increases probability of path being

followed

Note :-

pheromone trails - Chemicals' secreted from the body of an

individual.

2. Natural Clustering

There are typically three distinct elements of structure:

The protective and ribbed cone-shaped outer walls (also featuring

ventilation ducts).

The hive consists of thin horizontal lamellae supported by pillars. A

flat floor structure, sometimes exhibiting cooling vents in a spiral

formation.

The royal chamber: a thick walled enclosure for the queen, with small

holes in the walls to allow workers in and out. This is usually well

protected underneath the hive structure, and is where the queen lays

her eggs.

3. Bird Flocking

These flocks may be very large, in the tens of thousands of birds, and show coordinated turning and wheeling movements.

The recipe that achieves realistic swarm behaviour is this triplet of steering behaviours to be followed by each individual in a swarm: Separation: steer to avoid coming too close to

others. Alignment: steer towards the mean heading of

others. Cohesion: steer towards the mean position of

others.

COLLISION AVOIDANCE Rule 1: Avoid Collision with neighboring birds

VELOCITY MATCHING Rule 2: Match the velocity of neighboring

birds

FLOCK CENTERING Rule 3: Stay near neighboring birds

Inspired by foraging behavior of ants. Ants find shortest path to food source from nest. Ants deposit pheromone along traveled path which is used by other ants to

follow the trail. It has adaptability, robustness and redundancy.

4. Ant Colony Optimization

FORAGING BEHAVIOR OF ANTS

2 ants start with equal probability of going on either path.

FORAGING BEHAVIOR OF ANTS

The ant on shorter path has a shorter to-and-fro time from it’s nest to the food.

FORAGING BEHAVIOR OF ANTS

The density of pheromone on the shorter path is higher because of 2 passes by the ant (as compared to 1 by the other).

FORAGING BEHAVIOR OF ANTS

The next ant takes the shorter route.

FORAGING BEHAVIOR OF ANTS

Over many iterations, more ants begin using the path with higher pheromone, thereby further reinforcing it.

FORAGING BEHAVIOR OF ANTS

After some time, the shorter path is almost exclusively used.