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History of NewTrajectoryControl|
With the work of Robert Ellenberg Look ahead has been greatly improved. Originally the TP could only look 1 segment ahead. This worked well for most machining operations - but large gcode programs made up of short line/arc segments run poorly at higher speeds. This page is comparing Linuxcnc's current TP (on segment look ahead) with the new TP (Robs work) and also some other machine controls. |
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With the work of Robert Ellenberg look-ahead has been greatly improved. Originally the TP could only look 1 segment ahead. This worked well for most machining operations - but large gcode programs made up of short line/arc segments ran poorly at higher speeds. This page is comparing Linuxcnc's current TP (on segment look ahead) with the new TP (Robs work) and also some other machine controls. |
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This is the current TP strait G64. Notice the horizontal divisions. It had to be set to 1sec/div to fit the whole program |
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This is the current TP straight G64. Notice the horizontal divisions. It had to be set to 1sec/div to fit the whole program |
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This is the New TP strait G64. Now set to 500msec/div (that is twice as fast...) |
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This is the New TP straight G64. Now set to 500msec/div (that is twice as fast...) |
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Now this is mach running the path with strait G64. It seems to run it quite a bit faster. (about 400ms faster) but you can also see that it violates the acceleration constraints >40in/s^2 and approaching 50in/sec^2 |
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Now this is mach running the path with straight G64. It seems to run it quite a bit faster. (about 400ms faster) but you can also see that it violates the acceleration constraints >40in/s^2 and approaching 50in/sec^2 |
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Mach actual path for strait G64 (actually - all mach has is G64 as far as I can tell - if you want to adjust path following - it is done in the machine config. (not adjustable by gcode)) |
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Mach actual path for straight G64 (actually - all Mach has is G64 as far as I can tell - if you want to adjust path following - it is done in the machine config. (not adjustable by gcode)) |
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Now - I modified the config setting in mach 'CV Dist Tolerance_____Units' to get it to follow the path as close as linuxcnc does with P.1Q.1.. A setting of .5 (what ever that means) seems to be closer deviation wise. (this is comparing apples to oranges I know) |
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Now - I modified the config setting in Mach 'CV Dist Tolerance_____Units' to get it to follow the path as close as linuxcnc does with P.1Q.1.. A setting of .5 (whatever that means) seems to be closer deviation wise. (this is comparing apples to oranges, I know) |
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This is machs following of path with the above 'CV Dist Tolerance_____Units' set to .5 |
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This is Mach's following of path with the above 'CV Dist Tolerance_____Units' set to .5 |
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Here is another screenshot of mach running a profile flat out with G64. (again the graph in the background is .5mm squares) |
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Here is another screenshot of Mach running a profile flat out with G64. (again the graph in the background is .5mm squares) |