The point table of a VKRC, KRC and Fanuc program has a submenu Path (TCP) in its context menu. It calculates how the TCP really moves between the points of the program - straight lines, circular arcs, PTP motions and the approximation (Überschleifen, CNT, C_DIS) - and uses it for measuring, checking and inserting points.

• Path length of selected motions / from first to last selected point
• Estimated motion time
• Arc information
• Point deviation from neighbours
• Check approximation
• Find long segments
• Check switch points (BS Schaltpkt, PS, TRIGGER WHEN PATH)
• Insert point on path at distance
• Export path to CSV
• How the path is calculated and how accurate it is
• How accurate is the motion time?
• Licence and demo mode

▲ Which motions are used

The path follows the motions in the order of the file: every motion fold (VKRC, KRC) or motion line (Fanuc) is one step, from the target point of the previous motion to its own target point. Subprogram calls, loops and jumps are not followed. A point used several times in the program appears several times on the path.

Functions that work on a range (motion time, approximation, long segments, switch points, CSV) use the part of the program from the first to the last use of the selected points. With fewer than two selected points they use the whole program.

▲ Path length of selected motions

Select two or more points that are used one after another in the program (e.g. the points of one glue seam) and choose Path (TCP) » Path length of selected motions. The window shows every motion with

• Length - length of the real path, with the approximation curves,
• Geometry - length without approximation (as with Genau = 0, VE = 0 %, FINE),
• Quality - exact, approx. or estimate (see below),
• s - cumulative length from the first selected point.

If the selection consists of several separate parts of the program, their lengths are summed. Copy puts the table into the clipboard (for Excel), Save CSV... writes it to a file.

Sum of selected rows - in the result windows of the path length, motion time, long segments and CSV export you can select rows with the mouse (click, Shift+click, Ctrl+click). The line above the table shows at once the number of selected rows and their summed length and time, e.g. the length and the time of one part of a seam.

▲ Path length from first to last selected point

It is enough to select the first and the last point, e.g. the start and the end of a seam. The whole path between them is measured, including all points that are not selected.

▲ Estimated motion time

For every motion the time is calculated from the path length and the programmed speed:

• VKRC: VB of LIN, CIR, KLIN, KCIR, SLIN, SCIR [mm/s],
• KRC: Vel of LIN and CIRC from the LDAT [m/s],
• Fanuc: mm/sec, cm/min, inch/min of L and C.

Two values are shown:

• Time at programmed speed - as if the robot moved all the time at the programmed speed. This is the lower bound.
• With acceleration and braking - additionally the robot starts and stops with a constant path acceleration (default 2 m/s²) at every point without approximation. Short motions that never reach the programmed speed are calculated with a triangular speed profile.

PTP motions (speed in %), motions with time or angular speed and unknown speeds are not included; their number is shown in the window. The acceleration can be changed in the settings file, group Path_Tools, key CP_Acceleration_mm_s2.

▲ Arc information

For every circular motion (CIR, KCIR, SCIR, CIRC, C) whose target or auxiliary point is selected: radius, angle, arc length, chord, centre point and the position of the auxiliary point along the arc (50 % = in the middle). Remarks warn about

• an auxiliary point close to the start or target point (the circle then reacts strongly to small errors, e.g. after touch up),
• almost collinear points (very large radius),
• arcs longer than 180° and very small radii.

The start point of the arc is the target point of the previous motion. For Fanuc C P[a] : P[b] P[a] is the via point and P[b] the target.

▲ Point deviation from neighbours

Distance of the selected point from the straight line through the previous and the next point, and the change of direction in the point. A point on a straight seam should have a deviation close to 0 - this helps to find points that "jump out" after touch up.

▲ Check approximation

The controller never starts the approximation earlier than in the middle of the neighbouring motions. If Genau (VKRC), C_DIS (KRC) or CR / CD (Fanuc) is larger than half of the incoming or outgoing motion, it is reduced - silently. The path then passes closer to the point than programmed, and the length and the time change. The window lists all points with the approximation given in mm, and marks the points where the programmed distance cannot be reached. VE % and CNT are not checked.

▲ Find long segments

Lists the motions longer than the given length (default 50 mm - the usual maximum distance between glue points). The length is the geometric length without approximation.

▲ Check switch points

Switch points with a distance in mm are compared with the length of the motion they lie in:

• VKRC: BS A1544 ( EIN ) = !E15 Schaltpkt: -5 [mm]: -50[ms],
• Fanuc: PS +20mm -0.05sec GO[11]=(2),
• KRC: TRIGGER WHEN PATH = -20 DELAY = 0 DO ....

A positive distance lies after the point, in the next motion; a negative distance lies before the point, in the motion to the point. A switch point outside its motion is marked as an error.

▲ Insert point on path at distance

Select one point and choose Insert point on path at distance.... The new point is placed on the motion after the selected point, at the given distance from it (the dialog shows the length of the motion; the default is the middle). The position lies exactly on the straight line, the orientation is interpolated between both points (as the robot does it on a LIN motion), the linear axis E1 is interpolated, too.

• VKRC: a new motion fold is inserted with the motion type and the data of the next point (KLIN / LIN / SLIN, VB, Genau / VE, ACC, TOOL, BASE) and the next free point number.
• KRC and Fanuc: the same window as for Insert motion point opens with the calculated coordinates (choice cartesian / axis point, point editor); the point is inserted with Apply, Cancel leaves the program unchanged. For Fanuc the new motion takes over the motion type, speed, termination and options of the divided motion (e.g. L ... 200mm/sec CD10 ACC100 RTCP); time and distance switch options (TB/TA/DB ...,P-SPS, DO[], CALL) and Skip are not copied, so the logic of the old point is not executed twice.

A point can be inserted only in a linear motion. Switch points (Schaltpunkte) of the neighbouring points keep their distances, which now refer to the shorter motion - check them with Check switch points. The function uses the same licence as Add point in the Robot View.

▲ Export path to CSV

Table of all motions of the range with the segment lengths, the cumulative length s, speed, approximation and time - for documentation or further analysis in Excel.

▲ How the path is calculated and how accurate it is

Motion	Model	Accuracy
LIN, KLIN, SLIN, L	straight line	exact
CIR, KCIR, SCIR, CIRC, C	circle through the start, auxiliary and target point	exact
PTP, KPTP, SPTP, J	straight line in joint space (synchronous PTP), TCP path from the forward kinematics every ≤ 0.5°	good, requires the kinematics in the robot configuration
Genau [mm], C_DIS	corner replaced by a curve from the distance d before to d after the point, d limited to half of the neighbouring motions	approx. - KUKA does not publish the shape of the curve; the difference to a tangential arc is 0.01 mm at 30°, 0.2 mm at 60° and about 1 mm at a 90° corner (d = 20 mm)
VE %, CNT, CR / CD, C_VEL, C_ORI, PTP approximation	same curve, distance estimated	estimate - the real rounding depends on speed and acceleration

The length is calculated in the TOOL / BASE (UT / UF) of the target point of every motion - with a stationary gun (external TCP) this is the path on the part. Motions with a change of TOOL or BASE are calculated without approximation and marked as estimate.

Not modelled: a stop of the advance run (e.g. WAIT FOR, WARTE BIS), which cancels the approximation, spline motions (SPL), CIRC with circle angle CA, Fanuc INC, Offset / Tool_Offset / VOFFSET (estimate), UF:F / UT:F.

For a typical glue seam (KLIN / KCIR, Genau ≈ VB / 5, small changes of direction) the model differs from the programmed geometry only in the approximation curves, so the error of the length is expected to be well below the error of the former point-to-point (chord) measurement. It has not yet been compared with a trace of a real robot.

▲ How accurate is the motion time?

The motion time is an estimate, not a cycle time. The real robot controller plans every motion with acceleration and jerk limits, axis speed limits, reduced speed during reorientation and in the approximation, and a program contains waits, handshakes with the PLC and technology times. The estimate is closest to reality for long CP motions (glue, sealing) at constant speed; for short motions the real time is longer.

The path tools do not calculate a cycle time. They give a fast, transparent estimate directly in the editor - useful to compare variants, to find slow parts of a seam and to check a program before the robot is available.

▲ Licence and demo mode

The path tools use the licence of the editor of the robot: VKRC for VKRC programs, KRC for KRC programs and VFanuc for Fanuc programs. Insert point on path at distance uses the licence of Add point in the Robot View.

Without the licence the path tools work in demo mode:

• every function calculates at most the first 25 motions of the selected range (the result window says how many motions were calculated and how many the range has),
• Copy, Save CSV... and Export path to CSV... are not available.

This is enough to try every function on a part of a real program; the full range and the export of the results require the licence.