Difference between revisions of "Concatenation of Movements"
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=== Discretization === | === Discretization === | ||
| − | [[File:AXY;Conncatenation.png]] | + | |
| + | Discretization is a phenomnenon occuring in motion-concnatenation. A movement that ends with non-zero final velocity can never exactly end at the last motion sample. As a motion profile generation is done in every system sample at a specified sampl rate the last sample will never be exact. In other words: | ||
| + | <math>v \cdot n \cdot T \neq L </math><br> | ||
| + | |||
| + | The overshoot will be transferred to the next movement as it's new initial position. In cases of transitions between circles and lines the appropriate projection-factor will be taken into account. | ||
| + | |||
| + | The example below shoes two movements (to A and then to B): | ||
| + | <pre> | ||
| + | MOVE A vcruise = 100 vfinal = 100 | ||
| + | MOVE B vcruise = 100 | ||
| + | </pre> | ||
| + | |||
| + | it is important to notice that the second motion will start from a point that is little bit further off from the point A. | ||
| + | |||
| + | [[File:AXY;Conncatenation.png | Discretization]] | ||
| + | |||
| + | ==== Path-PLS ==== | ||
| + | {{Note| In case of motion concatenation and PLS the second movement will miss the PLS set on 0% ! As the 0% actually never happens.}} | ||
Revision as of 11:48, 25 March 2012
Contents
Concatenation of movements
In aico.control system two motions can be "glued" together using a non-zero final velocity value. This method is called concatenation. It is a primitive way of blending. Each motion is fully executed according to its interpolation specification in opposite to blending(CP,SP or AI) where the path is modified in order to fit to the motion constrains.
How the concatenation is issued?
Depending if the given motion element is group/axis or robot the following final-velocity properties are used:
- In case of group/axis: VFINAL (comes together with VCRUISE).
- In case of robot : VFTRAN and VFROT (comes together with VTRAN and VROT).
Some special issues that need to be taken into account
Profiling
- It is important to note that when specifying final velocity that the actual final velocity can differ. The system motion profiler tries to generate the best (fastest) motion profile under the given limitations. The actual obtained final velocity will depend on initial velocity of the movement, movement length and all the motion limitations (acceleration/deceleration max, jerk max, etc.).
- In case a series of conncatenedted motions is is issued and the last one starts with such a high velocity that the movement can not be stopped at the end an AUTOMATIC BRAKING error will be sent to the user.
- In case the final velocity is too high the biggest achievable final velocity will be reached instead.
Discretization
Discretization is a phenomnenon occuring in motion-concnatenation. A movement that ends with non-zero final velocity can never exactly end at the last motion sample. As a motion profile generation is done in every system sample at a specified sampl rate the last sample will never be exact. In other words:
The overshoot will be transferred to the next movement as it's new initial position. In cases of transitions between circles and lines the appropriate projection-factor will be taken into account.
The example below shoes two movements (to A and then to B):
MOVE A vcruise = 100 vfinal = 100 MOVE B vcruise = 100
it is important to notice that the second motion will start from a point that is little bit further off from the point A.
Path-PLS
 | NOTE |
| In case of motion concatenation and PLS the second movement will miss the PLS set on 0% ! As the 0% actually never happens. |