Virtual Machine Overview

The ICAM Virtual Machine (VM) simulator graphically depicts the operation and motions of a CNC machine during post processing. VM provides feedback to CAM-POST (the post processor), which can use this information to provide collision detection and avoidance.

Machine simulation includes the following:

  • A computerized model of the machine

  • A CNC control simulator

  • Tool, Part, Stock and Fixture definitions

The machine model is developed and maintained using CAM-POST QUEST. The resultant data is stored in a CAM-POST database (.dbf) file with the post processor data, or externally in a binary "dmp" file format. The model describes the kinematics and the physical characteristics of the machine. The model is in an ICAM proprietary format. Models from other popular machine simulation systems cannot be imported at the present time.

VM includes a virtual controller that is fully integrated with the post processor. The virtual controller requires no additional logic to manage the simulation. The controller automatically handles positioning, interpolating and canned cycle motions, to the extent supported by the real machine. It simulates work piece and tool compensation features to more accurately test collisions using expected tooling data. The VM controller also provides features to move and test machine axes.
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Tool definitions follow the ISO standard 7-parameter cutter format, which at the present time limits simulation to milling applications only. Tool holders are defined by a swept 2D profile. Tools and holders can be automatically or manually associated with each other. The finished part, rough stock and fixtures can all be defined using simple primitives and/or by importing STL files. VM does not perform material removal simulation (commonly called part verification). VM does however check for collisions between the machine, tooling, part, stock and fixtures.
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VM serves two primary purposes:

  • Collision detection and avoidance during post processing

  • Visual confirmation of kinematics during post processor development

CAM-POST QUEST provides additional features used to define the kinematics and physical representation of a CNC machine. This data is referred to as the "model" which can be stored in the database with its associated post processor. A model can be, but need not be, associated with a single post processor1. In addition to the machine, the model designer can define standard viewpoints, lighting (shown below), fixtures and tooling.

CAM-POST GENER uses VM to detect and, where possible, avoid collisions. Collision detection can account for the effects of work piece and tool compensation, given experimental or actual values for compensation offsets. Collision detection is a natural part of the look-ahead optimizations that GENER performs during path planning, meaning that GENER can automatically choose an appropriate tool path to avoid collisions. The machine simulation can be displayed in one of the GENER output windows, synchronized with other GENER output. Collision detection and avoidance can be active even when the simulation is not being show, for example, when running GENER in a minimized state.

VM is currently available for Windows NT and compatible systems only.

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