N series arm orientations
The N series can be operated in various arm orientations within a given work envelope as shown below:
Orientation of N series is different depending on "with" and "without" offset.
Offset is a distance between Joint #2 and Joint #1.
Examples of orientation "with" and "without" offset are shown below.
With offset: Distance from Joint #2 and Joint #1 is not 0mm
Without offset: Distance from Joint #2 and Joint #1 is 0mm
Without offset (Illustrations: N2-A450SR)
| Arm orientation | ||
|---|---|---|
| Righty arm orientation | Lefty arm orientation | |
| Above elbow orientation |  |  |
| Below elbow orientation |  |  |
With offset (Illustration: N6-A1000S)
| Arm orientation | ||
|---|---|---|
| Righty arm orientation | Lefty arm orientation | |
| Above elbow orientation |  |  |
| Below elbow orientation |  |  |
To specify the arm orientation of the N series, add a forward slash (/) followed by:
- L (for Lefty hand orientation) or R (Righty hand orientation)
- A (Above elbow orientation) or B (Below elbow orientation)
- NF (NoFlip wrist orientation) or F (Flip wrist orientation)
There are eight available orientations as shown below, however, some combinations are not available depending on the point.
Available Orientation
- 1: /R /A /NF
- 2: /L /A /NF
- 3: /R /B /NF
- 4: /L /B /NF
- 5: /R /A /F
- 6: /L /A /F
- 7: /R /B /F
- 8: /L /B /F
At some points in the work envelope, the robot can have the same position and orientation even if the fourth joint or the sixth joint is rotated 360 degrees. To distinguish these points, the J4Flag and J6Flag point attributes are provided.
To specify the J4Flag, add a forward slash (/) followed by:
- J4F0 (-180 < fourth joint angle <= 180), or
- J4F1 (fourth joint angle <= -180 or 180 < fourth joint angle)
To specify the J6Flag, add a forward slash (/) followed by:
- J6F0 (-180 < sixth joint angle <= 180), or
- J6F1 (-360 < sixth joint angle <= -180 or 180 < sixth joint angle <= 360), or
- J6Fn (-180*(n+1) < sixth joint angle <= -180*n or 180*n < sixth joint angle <= 180*(n+1))
Singularity
The orientation in the boundary where the arm orientation switches to the other.
Hand singularity: The boundary where Righty hand orientation and Lefty hand orientation switch
Elbow singularity: The boundary where Above elbow orientation and Below elbow orientation switch
Wrist singularity: The boundary where NoFlip wrist orientation and Flip wrist orientation switch
For the N series robot, Hand / Wrist singularities exist also inside the motion range like the 6-axis robot. When jogging near the singularity, pay attention to the same points as the 6-axis robot.
For common considerations, see below.
The following describes the elbow singularity area that is unique for 6-axis robots.
Elbow singularity area
For the N series robot, the singularity exists where the P point is on the sphere shown in the figure below. The P point cannot be inside the sphere. Therefore, CP motion to pass inside the sphere is not available.
Elbow singularity area avoidance motion
When the robot passes through the sphere as shown in the figure below, the robot behaves differently depending on the singularity avoiding function (AvoidSingularity) mode. The operation is as follows.
Mode: SING_AVOID
The robot moves to the end point while avoiding the elbow singularity area as indicated with a red line (P-point trajectory) in the figure below. Also, an error occurs in the following cases:
- If SpeedS setting value is too large, error 4242, 4243, 4255, or 5044 occurs. The errors can be prevented by setting SpeedS lower.
- If the motion is stopped/paused, or the safety door is opened during the singularity avoiding motion (PTP motion), error 4242, 4250, 4252, or 4256 occurs. Do not stop the operation or open the safety door during the singularity avoiding motion.
- If the singularity avoiding motion mode (SING_AVOID) is selected for N series, an error 4255 or 4256 occurs.
Mode: Other than SING_AVOID
The error 4252 occurs when the robot touches the elbow singularity area as indicated with a blue line (P-point trajectory) in the figure below.
The elbow singularity area (Flange) is an area when Joint #5 is 0°.
| Symbol | Description |
|---|---|
| a | Start point |
| b | End point |
| c | Elbow singularity area (Flange) |
| d | Elbow singularity area (P point) |
Note:
The pass motion can be confirmed by the sample simulator program “N2_sample”.
With Jump3, Jump3CP, and JumpTLZ, the motion to pass the elbow singularity area is not available. (Shoulder and wrist singularity pass motions are possible.)
In the singularity avoiding motion, the Joint #4 and #6 may rotate largely.
In the singularity avoiding motion, onward and backward paths may differ.
To display the elbow singularity area and elbow singularity neighborhood in the simulator, set the robot's Show Singularity Area property to "True". The Show Singularity Area property is only displayed for the N series.
