ML_KinPolyTransP and ST_CONTINUOUS_SLOPE

[bostroemc]

I am using KinInterface with arKinCtrl_gb[].CoordMode.SlopeType = MB_KIN_CONT_MOTION.ST_CONTINUOUS_SLOPE and ML_KinPolyTransP to traverse a space curve at constant speed.  If I issue the motion commands in quick succession (for example, all within a single scan), this works beautifully:

However, if I pause for some time between commands, I see a break in the continuous motion.  For example, if I pause for 50 ms between issuing motion commands 1-6 and motion commands 7-12, the motion pauses at the end of move 6 as shown below.  Note that motion command 1 is still active when then final six motion commands are issued.  (See also attached video.)

The associated code looks like this:

Is this there any way to avoid this behavior?  In my actual use case I would like to traverse a very long space curve at constant speed and not all target points are immediately available (i.e. at start). 

Sample ctrlX PLC project attached.

[CodeShepherd · Accepted solution]

The thing is that our kernel uses several commands for blending and and then prepares them to a moveable curve. If there are less commands available as expected a stop will be inserted, that will not be overwritten even if more/new commands are coming in.

To tell the kernel to not insert that stop the command option ML_KinContour is needed. Be aware that if not enough commands are available in the buffer at the end of a movement and option is still active an error will occur.

Procedure would be as follows:

1. switch on ML_KinContour (and as before ML_KinPolyTransP)
2. insert first commands
3. movement is started immediately
4. insert at some point further commands
5. insert last commands of your contour
6. switch off ML_KinContour (and as before ML_KinPolyTransP)
7. commands will all be finished and movement ends

There is also the possibility to delay the start of the movement by inserting a number of must have commands available via the input "PrepCmds".