Synchro PTP The leading axis is the axis that takes longest to reach the end point. The ve-locity specified in the inline form is taken into consideration.
Status & Turn Status and Turn serve to define an unambiguous axis position in such cases where the same TCP position can be achieved with different axis positions.
Motion type Meaning Application example
Point-to-point:
Axis-specific motion: The robot guides the TCP along the fastest path to the end point. The fastest path is generally not the shortest path and is thus not a straight line. As the motions of the robot axes are rotational, curved paths can be executed faster than straight paths.
The exact path of the mo-tion cannot be predicted.
The leading axis is the axis that takes longest to reach the end point.
SYNCHRO PTP: All axes start together and also stop in a synchronized manner.
The first motion in the pro-gram must be a PTP mo-tion, as Status and Turn are evaluated only here.
Free points in space
Fig. 6-3: Synchro PTP
The robot controller only takes the programmed Status and Turn values into consideration for SPTP motions. They are ignored for path (CP) motions. The first motion instruction in a KRL program must therefore be a complete SPTP instruction of type POS or E6POS in order to define an unambiguous starting position (or a complete SPTP instruction of type AXIS or E6AXIS).
Approximate positioning
In order to accelerate the motion sequence, the controller is able to approxi-mate motion commands labeled with CONT. Approxiapproxi-mate positioning means that the point coordinates are not addressed exactly. The robot leaves the path Fig. 6-4: Different axis positions due to different Status and Turn values
DEFDAT MAINPROGRAM ()
DECL POS XPOINT1={X 900, Y 0, Z 800, A 0, B 0, C 0, S 6, T 27}
DECL FDAT FPOINT1 …
… ENDDDAT
Fig. 6-5: Approximation of an SPTP point
along an approximate positioning contour that leads into the exact positioning contour of the next motion command.
Advantages of approximate positioning:
There is less wear to the kinematic system, as it is no longer necessary to brake and accelerate between the points (see point 1).
The cycle time is optimized and the program is executed more quickly (see point 2).
In order to be able to perform an approximate positioning motion, the controller must be able to load the following motion commands. This is carried out by the computer advance run.
Approximate positioning in the SPTP motion type
Procedure for creating SPTP motions
Preconditions
T1 mode is set.
A robot program is selected.
1. Move the TCP to the position that is to be taught as the end point.
Fig. 6-6: Comparison of exact positioning and approximate positioning
Motion type Feature Approximation
distance
The approximate positioning contour cannot be predict-ed!
Specified in % or mm
2. Position the cursor in the line after which the motion instruction is to be in-serted.
3. Menu sequence Commands > Motion > SPTP.
Alternatively, the softkey Motion can be pressed in the corresponding line.
An inline form appears:
SPTP inline form
4. Enter parameters in the inline form.
Fig. 6-7: Motion command
Fig. 6-8: Inline form “SPTP” (individual motion)
Item Description
1 Motion type SPTP
2 Point name for end point. The system automatically generates a name. The name can be overwritten.
Touch the arrow to edit the point data. The corresponding option window is opened.
3 CONT: end point is approximated.
[Empty box]: the motion stops exactly at the end point.
4 Velocity
1 … 100% for SPTP
0.001 … 2 m/s for SLIN
5 Name for the motion data set. The system automatically gener-ates a name. The name can be overwritten.
Touch the arrow to edit the point data. The corresponding option window is opened.
6 This box can be displayed or hidden by means of Switch param-eter.
Name of the data set containing logic parameters. The system automatically generates a name. The name can be overwritten.
Touch the arrow to edit the data. The corresponding option win-dow is opened.
5. Enter the correct data for the tool and base coordinate system in the option window “Frames”, together with details of the interpolation mode (external TCP: on/off) and the collision monitoring function.
6. The acceleration can be reduced from the maximum value in the option window “Motion parameters”. If approximate positioning has been activat-ed, the approximation distance can also be modified. Depending on the configuration, the distance is set in mm or %.
Fig. 6-9: Option window: Frames Item Description
1 Tool selection.
If True in the box External TCP: workpiece selection.
Range of values: [1] … [16]
2 Base selection.
If True in the box External TCP: fixed tool selection.
Range of values: [1] … [32]
3 Interpolation mode External TCP:
False: The tool is mounted on the mounting flange.
True: The tool is a fixed tool.
4 Collision detection
True: For this motion, the robot controller calculates the axis torques. These are required for collision detection.
False: For this motion, the robot controller does not calcu-late the axis torques. Collision detection is thus not possi-ble for this motion.
7. Save instruction with Cmd OK. The current position of the TCP is taught as the end point.
Fig. 6-10: Option window “Motion parameters” (SPTP) Item Description
1 Axis acceleration. The value refers to the maximum value speci-fied in the machine data.
1 … 100 %
2 This box is not available for SPTP segments. In the case of indi-vidual SPTP motions, this box is only displayed if CONT was selected in the inline form.
Furthest distance before the end point at which approximate posi-tioning can begin.
The maximum permissible value is half the distance between the start point and the end point. If a higher value is entered, this is ignored and the maximum value is used.
3 Gear jerk. The jerk is the change in acceleration.
The value refers to the maximum value specified in the machine data.
1 … 100 %
Fig. 6-11: Saving the point coordinates with “Cmd OK” and “Touchup”