More About Joints and Constraints

aremind.gif (956 bytes) DMU Kinematics Simulator lets you define and edit 17 different joint types.

We can classify these joints under 4 different categories depending on the way they are defined. Of course one specific joint can belong to several categories:

  • Joints using assembly constraints (i.e. a revolute joint is defined by two constraints (coincidence between two lines) and an offset between two planes
  • Joints using topological or geometrical elements (i.e. a point curve joint is defined by a point and a curve)
  • Compound joints using other joints (i.e. a gear joint is defined with two revolute joints)
  • Axis-based Joints (defined with axis systems) (i.e. universal joint)

DMU Kinematics Simulator lets you define the following joints using axis systems ():

  • u joint
  • prismatic
  • revolute
  • cylindrical
  • spherical

The table below describes the joint types with respect to the categories they belong to (the way they are defined)




General case
Sub-compound joints
Axis systems
with geometry
Revolute  I_RevoluteJntP2.gif (246 bytes) X   X  
Prismatic  I_PrismaticJntP2.gif (238 bytes) X   X  


I_CylindricalJntP2.gif (235 bytes) X      
Spherical  I_SphericalJntP2.gif (234 bytes) X   X  


I_PlanarJntP2.gif (182 bytes) X      
Roll Curve        X
Slide Curve        X
Point Curve        X
Point Surface       X
U Joint      X
Gear joint X X    
Rack Joint X X    
Cable Joint X X  
Screw Joint X      
CV Joint       X