Interpolation

The robot motion control creates a profile of the motor setpoint positions for all operating states of the kinematic model. The motion path is generated by means of path interpolation. The target is given in Cartesian coordinates.

Path interpolation

Path interpolation generates a geometrically defined path of the translational and rotary degrees of freedom.

The robot tool moves along a path defined in space consisting of straight lines or circular arcs and blending curves. For the transitions between 2 straight segments and/or circular arcs, you can define a rounding of the path (blending).

PTP interpolation

During PTP interpolation, the joint axes are moved synchronously to the joint axis values in the target position.

Note the following during PTP interpolation:

  • PTP interpolation is only possible in static coordinate systems.
  • The path resulting at the tool coordinate system during PTP interpolation via the direct kinematic transformation is always the same regardless of the motion parameters, i.e. also independent of the speed, such as in blending.

Application cases for PTP interpolation:

  • Changing the constellation in program mode
  • Moving in or near singularities
  • Alignment of joint axes when using a kinematic model with more joint axes than Cartesian degrees of freedom or without inverse kinematic transformation prior to Cartesian interpolation (e.g. JOG_CART, LIN, CIRC). For this purpose, the target pose must be specified in a Cartesian coordinate system.
  • Approaching a clearly defined position at the start of an SRL program (constellation and joint axis phases when specifying the target pose in a Cartesian coordinate system or alternatively explicit specification of the positions of the joint axes)
  • Moving at maximum permissible speed of the joint axes

Blending between a linear or circle segment and a PTP segment is subject to the following restrictions in the current version of the software:

  • For joint axes that can be parameterized via the JointPhase (see chapter Kinematic models), the difference between SWLS_Max and SWLS_Min must be less than 360°.
  • Not supported in the user coordinate system (neither static nor in motion)
  • Not possible in conjunction with the tangential control
  • Changing the tool transformation is not permitted