– Window detectors

Docs: Setpoint jump detector

Mon, 01 Jan 0001 00:00:00 +0000

The setpoint jump detector catches a setpoint that jumps, for example a wrong target or a link that suddenly delivers another value. It watches how far the axis setpoint moves in one cycle, before and after the limiter, and takes the larger of the two.

It works on all axes at once, so it does not use windowDetectorsEnable: each axis has its own detector at root/AxesControl/axesSetpointJumpDetectors/windowDetectorNN.

What	Details
Unit	rad or m per cycle
At `low` or `high`	Warning `WA_SETPOINT_JUMP` (210)
At `tooLow` or `tooHigh`	The axes make a smooth stop and the application forces a disengage, `FD_SETPOINT_JUMP` (309)
Paused	While the axis runs open loop, for example while it is referenced
Standard robot configuration	Enabled; `low`, `high` at `-0.02`, `0.02`; `tooLow`, `tooHigh` at `-0.05`, `0.05`

To choose the levels, work out the largest step a real move makes: the highest velocity times the cycle time. Set high a little above it and tooHigh well above it, and the negative levels the same.

Docs: Position window

Mon, 01 Jan 0001 00:00:00 +0000

The position window watches the actual position, so it catches an axis that is outside its range whatever the setpoint says. The limiter only keeps the setpoint in range; this detector is the check on the axis itself. It matters most for axes driven by a velocity or torque setpoint.

What	Details
Path	`actuatorControlLoopNN/positionWindowDetector`
Watches	`actuatorPositionActualFiltered`, in rad or m
Standard robot configuration	Present but disabled, with the default levels

Set low and high just outside the limiter’s position limits, and tooLow and tooHigh a little further out, still inside the mechanical end stops.

Docs: Tracking error window

Mon, 01 Jan 0001 00:00:00 +0000

The tracking error window watches how far the axis is from where it should be: the position target minus the actual position. A large error means the axis is blocked, has hit something, or the drive or controller is not doing what it should.

What	Details
Path	`actuatorControlLoopNN/positionErrorWindowDetector`
Watches	`actuatorPositionError`, in rad or m
Standard robot configuration	Present but disabled; `high` at `0.02` and `tooHigh` at `0.15`

To choose the levels, plot actuatorPositionError in Desk during the fastest moves you make. Set high and low a margin beyond the largest error you see, and tooHigh and tooLow further out.

Docs: Velocity window

Mon, 01 Jan 0001 00:00:00 +0000

The velocity window watches the actual velocity, so it catches an axis that moves too fast, for example after a wrong transformation or a drive fault.

What	Details
Path	`actuatorControlLoopNN/velocityWindowDetector`
Watches	`actuatorVelocityActualFiltered`, in rad/s or m/s

Set high and low a little beyond the limiter’s velocityLimit, and tooHigh and tooLow further out.

Docs: Acceleration window

Mon, 01 Jan 0001 00:00:00 +0000

The acceleration window watches the actual acceleration, worked out from the filtered actual velocity. It catches jolts, such as a collision or a sudden drive reaction.

What	Details
Path	`actuatorControlLoopNN/accelerationWindowDetector`
Watches	`actuatorAccelerationActualFiltered`, in rad/s² or m/s²

Because it is a derivative, this value is noisy. Set the levels a good margin beyond the limiter’s accelerationLimit, and use timeWindow to ignore short spikes.

Docs: Torque window

Mon, 01 Jan 0001 00:00:00 +0000

The torque window watches the actual torque at the load, which reveals a collision, a blocked axis or a load that is heavier than expected. It exists on axes whose drive reports a torque.

What	Details
Path	`actuatorControlLoopNN/torqueWindowDetector`
Watches	`actuatorTorqueActualFiltered`, in Nm

To choose the levels, plot actuatorTorqueActual in Desk during normal work, including the heaviest load. Set high and low a margin beyond what you see, and tooHigh and tooLow below what the mechanics can take.