16-03-2011, 11:47 AM
PRESENTED BY:
E.UDAY KIRAN
Swarm robots1.ppt (Size: 1.93 MB / Downloads: 143)
Swarm robots
WHAT IS A “SWARM ROBOTs”?
Swarm-bots are a collection of mobile robots able to self-assemble and to self-organize in order to solve problems that cannot be solved by a single robot.
A boid must observe the following rules :
• Avoidance rule
• Copy rule
• The center rule
• View
SWARM INTELLIGENCE
Swarm intelligence describes the way that complex behaviors can arise from large numbers of individual agents each following very simple rules.
SOFTWARE FROM INSECTS :
Local interactions between nearby robots are being used to produce large scale group behaviors from the entire swarm.
Ants , bees and termites are beautifully engineered examples of this kind of software in use.
developing swarm software from “group behavior building blocks” that can be combined to form larger, more complex applications are being developed.
ANT COLONY OPTIMIZATION
Ant colony optimization or ACO is a meta heuristic optimization algorithm that can be used to find approximate solutions to difficult combinatorial optimization problems.
ACO has been successfully applied to an impressive number of optimization problems.
APPLICATION OF ROBOT SWARMS:
There are many applications for swarms of robots.
Multiple vacuum cleaner robots .
Robots used for earthquake rescue .
A swarm of mars rovers.
OTHER TYPES OF SWARM ROBOTS :
Modular Robots : Lots of little robots can combine to create one big one.
Chain robots :
1. Long chains that can connect to one another at specific points .
2. Depending on the number of chains and where they connect, these robots can resemble snakes or spiders.
EXAMPLES:
a. Palo Alto Research Center’s (PARC) Polybot
b. Polypod
c. NASA’s snakebot
Lattice robot : Lattice robots move by crawling over one another, attaching to and detaching from connection points on neighboring robots.
• Modules can either have self-contained power sources, or they can share power sources through their connections to other modules.
Mobile reconfiguration robots are small,identical modules that can combine to form bigger robots.
(1)However, they don’t need their neighbors’
help to get from place to place- they can
move around on their own.
(2) They move independently until they
need to come together to accomplish
a specific task.
A GLANCE AT THE OTHER APPLICATIONS :
• Transport by groups of blind and non-blind robots.
Transport of objects of different shapes and sizes
CONCLUSION
1.Robots are going to be an important part of the future.
2.Once robots are useful, groups of robots are the next step, and will have tremendous potential to benefit mankind.
3.Software designed to run on large groups of robots is the key needed to unlock this potential.
Group selection
Consider a single gene locus with the alleles , which have the fitnesses and the allele frequencies respectively. Ignoring frequency-dependent selection, then genetic load (L) may be calculated as:
where wmax is the maximum value of the fitnesses and is mean fitness which is calculated as the mean of all the fitnesses weighted by their corresponding allele frequency:
If the mean fitness is 0, the load is equal to 1, but the population goes extinct.
where the ith allele is and has the fitness and frequency wi and pi respectively.
When the wmax = 1, then (1) simplifies to
Causes of genetic load
Load may be caused by selection and mutation.
Mutational load
This section requires expansion.Mutation load is caused when a mutation at a locus produces a new allele of either lesser or greater fitness. This lowers the average fitness of the population; a deleterious mutation has a lower relative fitness, lowering average load, while an advantageous mutation effectively increases the relative fitness of the existing allele, and thus also increases average fitness.
Selectional load
This section requires expansion.Selection occurs when the fitnesses of particular alleles are inequal, hence selection always exerts a load.
With directional selection, the allele frequencies will tend towards an equilibrium position with the fittest allele reaching a frequency in mutation-selection balance. As mutations are rare, this is effectively fixation. Consider two alleles and . If w1 > w2, then at equilibrium, and , hence , and .
Group selection
Consider a single gene locus with the alleles , which have the fitnesses and the allele frequencies respectively. Ignoring frequency-dependent selection, then genetic load (L) may be calculated as:
where wmax is the maximum value of the fitnesses and is mean fitness which is calculated as the mean of all the fitnesses weighted by their corresponding allele frequency:
If the mean fitness is 0, the load is equal to 1, but the population goes extinct.
where the ith allele is and has the fitness and frequency wi and pi respectively.
When the wmax = 1, then (1) simplifies to
Causes of genetic load
Load may be caused by selection and mutation.
Mutational load
This section requires expansion.Mutation load is caused when a mutation at a locus produces a new allele of either lesser or greater fitness. This lowers the average fitness of the population; a deleterious mutation has a lower relative fitness, lowering average load, while an advantageous mutation effectively increases the relative fitness of the existing allele, and thus also increases average fitness.
Selectional load
This section requires expansion.Selection occurs when the fitnesses of particular alleles are inequal, hence selection always exerts a load.
With directional selection, the allele frequencies will tend towards an equilibrium position with the fittest allele reaching a frequency in mutation-selection balance. As mutations are rare, this is effectively fixation. Consider two alleles and . If w1 > w2, then at equilibrium, and , hence , and .
Directional selection is a particular mode or mechanism of natural selection. In population genetics, directional selection occurs when natural selection favors a singlephenotype and therefore allele frequency continuously shifts in one direction. Under directional selection, the advantageous allele will increase in frequency independently of its dominance relative to other alleles (i.e. even if the advantageous allele is recessive, it will eventually become fixed). Directional selection stands in contrast tobalancing selection where selection may favor multiple alleles, and is the same as purifying selection which removes deleterious mutations from a population.
E.UDAY KIRAN
Swarm robots1.ppt (Size: 1.93 MB / Downloads: 143)
Swarm robots
WHAT IS A “SWARM ROBOTs”?
Swarm-bots are a collection of mobile robots able to self-assemble and to self-organize in order to solve problems that cannot be solved by a single robot.
A boid must observe the following rules :
• Avoidance rule
• Copy rule
• The center rule
• View
SWARM INTELLIGENCE
Swarm intelligence describes the way that complex behaviors can arise from large numbers of individual agents each following very simple rules.
SOFTWARE FROM INSECTS :
Local interactions between nearby robots are being used to produce large scale group behaviors from the entire swarm.
Ants , bees and termites are beautifully engineered examples of this kind of software in use.
developing swarm software from “group behavior building blocks” that can be combined to form larger, more complex applications are being developed.
ANT COLONY OPTIMIZATION
Ant colony optimization or ACO is a meta heuristic optimization algorithm that can be used to find approximate solutions to difficult combinatorial optimization problems.
ACO has been successfully applied to an impressive number of optimization problems.
APPLICATION OF ROBOT SWARMS:
There are many applications for swarms of robots.
Multiple vacuum cleaner robots .
Robots used for earthquake rescue .
A swarm of mars rovers.
OTHER TYPES OF SWARM ROBOTS :
Modular Robots : Lots of little robots can combine to create one big one.
Chain robots :
1. Long chains that can connect to one another at specific points .
2. Depending on the number of chains and where they connect, these robots can resemble snakes or spiders.
EXAMPLES:
a. Palo Alto Research Center’s (PARC) Polybot
b. Polypod
c. NASA’s snakebot
Lattice robot : Lattice robots move by crawling over one another, attaching to and detaching from connection points on neighboring robots.
• Modules can either have self-contained power sources, or they can share power sources through their connections to other modules.
Mobile reconfiguration robots are small,identical modules that can combine to form bigger robots.
(1)However, they don’t need their neighbors’
help to get from place to place- they can
move around on their own.
(2) They move independently until they
need to come together to accomplish
a specific task.
A GLANCE AT THE OTHER APPLICATIONS :
• Transport by groups of blind and non-blind robots.
Transport of objects of different shapes and sizes
CONCLUSION
1.Robots are going to be an important part of the future.
2.Once robots are useful, groups of robots are the next step, and will have tremendous potential to benefit mankind.
3.Software designed to run on large groups of robots is the key needed to unlock this potential.
Group selection
Consider a single gene locus with the alleles , which have the fitnesses and the allele frequencies respectively. Ignoring frequency-dependent selection, then genetic load (L) may be calculated as:
where wmax is the maximum value of the fitnesses and is mean fitness which is calculated as the mean of all the fitnesses weighted by their corresponding allele frequency:
If the mean fitness is 0, the load is equal to 1, but the population goes extinct.
where the ith allele is and has the fitness and frequency wi and pi respectively.
When the wmax = 1, then (1) simplifies to
Causes of genetic load
Load may be caused by selection and mutation.
Mutational load
This section requires expansion.Mutation load is caused when a mutation at a locus produces a new allele of either lesser or greater fitness. This lowers the average fitness of the population; a deleterious mutation has a lower relative fitness, lowering average load, while an advantageous mutation effectively increases the relative fitness of the existing allele, and thus also increases average fitness.
Selectional load
This section requires expansion.Selection occurs when the fitnesses of particular alleles are inequal, hence selection always exerts a load.
With directional selection, the allele frequencies will tend towards an equilibrium position with the fittest allele reaching a frequency in mutation-selection balance. As mutations are rare, this is effectively fixation. Consider two alleles and . If w1 > w2, then at equilibrium, and , hence , and .
Group selection
Consider a single gene locus with the alleles , which have the fitnesses and the allele frequencies respectively. Ignoring frequency-dependent selection, then genetic load (L) may be calculated as:
where wmax is the maximum value of the fitnesses and is mean fitness which is calculated as the mean of all the fitnesses weighted by their corresponding allele frequency:
If the mean fitness is 0, the load is equal to 1, but the population goes extinct.
where the ith allele is and has the fitness and frequency wi and pi respectively.
When the wmax = 1, then (1) simplifies to
Causes of genetic load
Load may be caused by selection and mutation.
Mutational load
This section requires expansion.Mutation load is caused when a mutation at a locus produces a new allele of either lesser or greater fitness. This lowers the average fitness of the population; a deleterious mutation has a lower relative fitness, lowering average load, while an advantageous mutation effectively increases the relative fitness of the existing allele, and thus also increases average fitness.
Selectional load
This section requires expansion.Selection occurs when the fitnesses of particular alleles are inequal, hence selection always exerts a load.
With directional selection, the allele frequencies will tend towards an equilibrium position with the fittest allele reaching a frequency in mutation-selection balance. As mutations are rare, this is effectively fixation. Consider two alleles and . If w1 > w2, then at equilibrium, and , hence , and .
Directional selection is a particular mode or mechanism of natural selection. In population genetics, directional selection occurs when natural selection favors a singlephenotype and therefore allele frequency continuously shifts in one direction. Under directional selection, the advantageous allele will increase in frequency independently of its dominance relative to other alleles (i.e. even if the advantageous allele is recessive, it will eventually become fixed). Directional selection stands in contrast tobalancing selection where selection may favor multiple alleles, and is the same as purifying selection which removes deleterious mutations from a population.