Path Objects

Introduction

A Path object manages coordinated multi-axis motion profiles. It is used when the motion profiles in an N-Dimensional space are required to follow a specific coordinated trajectory. Motion paths are constructed with high level linear and arc segments and downloaded to the controller. The controller calculates the real-time individual axis profiles.

Generally, Path motion is used when the trajectory through space is more important than the final target position. Several different algorithms can be applied to convert the linear and arc segment path into an interpolated trajectory.

Path trajectory generation is now supported by PT, PVT, SPLINE, BESSEL, BSPLINE, and BSPLINE2 algorithms. Blending of the corners is only available for the 2 bspline algorithms. Blending of a corner is when the path does not hit the corner but goes through a smooth arc.

Path object allows different velocity, acceleration, and time slice values for each path segment. The maximum velocity a segment can achieve is limited by several factors such as arc radius, line distance, time slice, and available acceleration/deceleration. Path segment parameters must be optimized for a particular application. This will be explained further in our Path Motion page listed under Software-MPI Topics section.

The current path algorithm supports up to 16 dimensions and 5000 points per path. Time slice has a valid range of 0.001 to 0.01 seconds. The smallest time slice should always be used for smoothest path command trajectory. User larger time slices only when you are reaching the maximum point limit because your path move is too long.

 

| Error Messages |

Methods

Create, Delete, Validate Methods
  mpiPathCreate Create a Path object
  mpiPathDelete Delete a Path object
  mpiPathValidate Validate a Path object

Configuration and Information Methods
  mpiPathParamsGet  
  mpiPathParamsSet  

Relational Methods
  mpiPathAppend  

Action Methods
  mpiPathMotionParamsGenerate  

 

Data Types

  MPIPathArc  
  MPIPathArcCenter  
  MPIPathArcEndPoint  
  MPIPathAttr  
  MPIPathDirection  
  MPIPathElement  
  MPIPathElementAttributes  
  MPIPathElementAttrMask  
  MPIPathElementType  
  MPIPathLine  
  MPIPathMessage  
  MPIPathParams  
  MPIPathPoint  

 

Macros

  mpiPathElementTYPE  
  mpiPathElementAttrMaskBIT  
  mpiPathElementATTR  

 

Constants

  MPIPathPointDIMENSION_MAX  
  MPIPathPointPOINTS_MAX