Constellation and joint axis phases
A Cartesian position (X, Y, Z, RotZ, RotY, RotX) can be approached with multiple constellations (e.g. elbows left/right) for many kinematic models and with multiples of 360° for rotary axes. The current constellation is output in the Basic.Out.SetpointPose.usiConstellation variables of the user interface and can optionally be displayed in the 3D simulation in RobotMonitor via the Control Panel.
The required constellation (Constellation) and joint phase (JointPhase) can be explicitly specified and approached in program mode by means of the PTP command. For the kinematic models it is indicated which constellations are possible and which axes can be parameterized via the parameter JointPhase.
If the overlapping of several rotary axes results in a Cartesian orientation value (RotZ, RotY, RotX), the position of the last rotary axis is determined from the Cartesian orientation value and the positions of the preceding rotary axes. For example, in a SCARA robot (kinematic model SCARA_LRRR_M10), the last rotary axis is the hand axis and only the shoulder and elbow axes are parameterized using JointPhase.
If possible, the travel range of the preceding rotary axes (shoulder, elbow in the example) should be limited to 360° via the software limit switches because parameterization via JointPhase is then no longer necessary.
Parameterization: Constellation
- Set value "0" (default setting)
- Retain last constellation reached by the robot
- Other values
- Explicit specification of the constellation
Parameterization: JointPhase
- Set value "0" (default setting)
- Automatic selection of the next phase without violation of the software limit switches
- Other values
- Explicit selection of the phase
- Negative JointPhase
- JointPosition ∈ ] JointPhase * 360°, (JointPhase + 1) * 360°]
- Positive JointPhase
- JointPosition ∈ ](JointPhase - 1) * 360°, JointPhase * 360°]
- Example: JointPhase = 1 means that the corresponding joint axis should move in the phase ]0, 360°].
