G-code and driving robots.

I know, I do have some experience in cnc machining. I'm just a little confused since xyz are typically linear if gcode (withG53) can be used to drive angular axes to specific angles like you would with a linear axes. Normally gcode treats ABC axes as only angular so thats not really the issue.

Also the the two control methods are usually called direct and vector control, the first uses xyzab values generated by CAM software and is machine specific since every machine has different A and B Axis configurations. The vector control replaces A and B values with (if I remember) K P and I values that describe the tool vector and attitude in 3D space. This is machine agnostic since the machine uses this to solve the tool position and the required axis positions.

For now im looking into the direct control since ROS takes care of the kinematics. I'm just wondering how I need to write the postprocessor for the ROS output and program creation functions.

I don't think that ROS is a particularly good fit with LinuxCNC. There is too much overlap in function.

LinuxCNC can work very well with what you are calling "vector control", so I am wondering why you are not following that approach?

How come? To my understanding linuxcnc is more of a low level controller that handles the hardware and code playback functions whereas ROS is more of a high level simulation environment with functional 3d models and full kinematics and design environment with rviz or gazebo. I don't see the overlap since ros lacks much of the hardware integration. Also I already have the 3d models and ros industrial setup ready to go. I mainly need something to bridge the hardware. I was going to write it myself but linuxcnc is more flexible.

And since want it to be made of separate components that work independently.

There is a ros integration project with linuxcnc that I've been looking into but I don't know if it works distributed and I doubt it would be independent then. At least not without two sets of configs.

Its also easier to just focus on one part at time and worry about integration later.

LinuxCNC can handle the kinematics required to convert TCP G-code to joint angles. So if you have "vector G-code" from a CAM system you don't need to include ROS in the chain.

If you have LinuxCNC installed then try opening the /sim/axis/vismach/5axis/table-rotary-tilting/xyzac-trt sample config to see a 3D simulatad machine tool running a vector G-code example. (The sample file is an impeller model, you can see the same file being machined on a real machine here )

I don't have a way to generate tcp gcode for the robot, ros does the simulations now and I only need a way to inject those values into linuxcnc(and capture into a file). ROS is the "cam" software in this case except it can be used to drive the robot directly. You can't achieve the same kind of control with linuxcnc alone. Nor can you integrate machine vision or obstacle avoidance etc into linuxcnc.

Thanks, I'll take a look at that.

LinuxCNC can work very well with what you are calling "vector control", so I am wondering why you are not following that approach?

This is exactly what I would like to do. Where can I read about it?