1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Particle swarm optimisation

Tags:
  1. May 12, 2016 #1

    Mke

    User Avatar

    Hello everyone,


    I have a short question about the PSO since I am a new comer to this field. how can we "add" position with velocity in the simple PSO algorithm, when they are of different units?
     
  2. jcsd
  3. May 12, 2016 #2

    jedishrfu

    Staff: Mentor

    Welcome to PF!

    Can you elaborate more on your question?

    What do you mean by units?

    What do you mean by "add" position to velocity?

    Is the posititon in inches and feet (ie english units) but the velocity is in meters/sec (metric units) ?
     
  4. May 12, 2016 #3

    Mke

    User Avatar

    Hello thank you for your reply.
    When the velocity is determined in the PSo algorithm, one needs to add the weighted velocity to the difference between the ( current positions and the best experience of that position ) . The former is velocity which is normally measured in different units than the position. In PSO it's not common to include units for the position and velocity that is what got me confused.
     
  5. May 12, 2016 #4

    jedishrfu

    Staff: Mentor

    What units?
     
  6. May 12, 2016 #5

    Mke

    User Avatar

    the units of velocity and position in the PSo are normally specified but they are still added together.
     
  7. May 12, 2016 #6

    jedishrfu

    Staff: Mentor

    What are the units for position?

    What are the units for velocity?
     
  8. May 12, 2016 #7

    Mke

    User Avatar

    they are not normally specified in the equations that produce the PSO. However, this is not important since regardless of the units, we are adding two different components that have different units. its like adding Kg and Km
     
  9. May 12, 2016 #8

    jedishrfu

    Staff: Mentor

    The best I can say here is that you compute the new position by using a velocity vector in say m/s times a small time increment in seconds to a change in position in meters:

    NewPositionmeters = OldPositionmeters + Velocitymeters/sec * delta-timeseconds
     
  10. May 12, 2016 #9

    Mke

    User Avatar

    Thank you but where does this delta-time come in the original equation that produces the new NewPosition which is merely : NewPositionmeters = OldPositionmeters + Velocitymeters/sec . Could you please further explain this ?

    Also, how the delta-time is normally represented when the PSO algorithm is coded?
     
  11. May 12, 2016 #10

    jedishrfu

    Staff: Mentor

    The delta time is implied in your equation to be 1 second.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Particle swarm optimisation
  1. Optimisation question (Replies: 1)

  2. Optimisation Problem (Replies: 2)

  3. Optimisation problem (Replies: 9)

Loading...