Lecture-5 (degrees of freedom(part - 1))

DEGREES OF FREEDOM  'F'

The minimum number of independent variables required to define the position or motion of system is known as degrees of freedom.
  • Degrees of freedom of an object in 3-D space system is shown below. 
Here we have maximum number of Motion is 6, that's 3 translational motion and 3 rotational motion.


  • Degrees of freedom of an object in 2-D space system are shown below.
Here maximum number of Motions we have are 3, that's 2 translational motion and 1 rotational motion. Planner mechanism are in 2- Dimensions.

Degrees of freedom (F) = 6 - Restraints
Restraints are number of those motion which are not possible. Restraints are always due to joints. 
For example-
Restraints= 3translational + 2rotational = 5
F = 6 - restraints = 6 - 5 = 1


NOTE 

  • All lower pairs have 1 degree of freedom except spherical pair. Spherical pair is the only lower pair whose degrees  of freedom is 3
  • All higher pairs have 2 degrees of freedom.

For more continue to lecture-6

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