High Precision Mode

This Mode is only available for the OndoSense apex PXXX

The High Precision Mode allows for the measurement of distance changes with a resolution as fine as 1 µm. When this mode is activated, the current distance to the target is stored as the reference distance, serving as the baseline or zero-point. Any subsequent change in distance is measured relative to this reference. If the distance to the target increases, the output values will be positive; if the distance decreases, the output values will be negative.

Common Use Cases for High Precision Mode:

1. Displacement & Drift Measurements Over Time:

   • High Precision Mode can be used to monitor the position of objects over extended periods, such as tracking the temperature drift of equipment.

2. Profile Measurement:

   • This mode is also ideal for measuring the profile of surfaces by moving the object perpendicular to the radar beam. Unlike laser sensors, High Precision Mode can effectively measure the profile of rough surfaces due to the opening angle and the radar spot size over which the distance is averaged.

Setup High Precision Mode

1. Initial Configuration with OndoNet:

   • Activate the High Precision Mode by clicking on the “Switch Mode” button in the Target View

   • Use OndoNet to set your measuring range. Adapt this to your use case to define the smallest possible range.

   • Configure the Amplifiers using AutoGain. The IQ data for a fix target should show oscillations without clipping.

   • Set the time interval for Reset High Precision Mode after a target loss.

   • Select "Maximum Accuracy" as your Profile as it is the first choice for best accuracy. Select “Long range - Slow moving objects” if you have a maximum distance beyond 6 metes.

2. Finalize Setup:

   • Disconnect your ConfigBox and establish the connection via Profinet .

Limitations

• The High Precision Mode is optimized for slow movements. When target movement exceeds 50 mm/s, target loss events may occur.

• The high-precision mode does not allow for a more accurate absolute distance measurement than via the standard absolute distance measurement. The initial absolute distance measurement will contain an error of a few hundred micrometers, that cannot be eliminated via the displacement measurement with the High Precision Mode.

• The high-precision mode will measure accurate distances for targets whose orientation towards the sensor stays relatively constant. For significant changes of the angle of the target towards the sensor, the accuracy of the high precision mode will be affected.

Target lost handling

When the high-precision mode is set up (i.e. the correct result data selector is chosen), upon receiving a MEASUREMENT-command, the sensor returns the high precision distance together with a target lost counter. As long as the sensor is capable of “locking” a given target, the target lost counter keeps the same value.

Sensor behavior in case of target lost events

Once a target lost event occurs, the sensor increases the target lost counter by one. (Note: If the maximum value of an unsigned 8-bit integer (255) is reached, the counter resets to zero.) The high-precision data block is now given by a status (TARGET_LOST = -7 (0xF9)), a target lost counter increased by one and a distance value of zero.

For 0.5 seconds the sensor will remain in this status before it automatically resumes operation of the high-precision mode. Such a resume resets the high-precision distance to 0. When the measurement resumes, the target lost counter does not increase further and does not reset to 0.

Manual restart of the high precision mode

To manually reset the high precision mode set the RestartHighPrecisionMode Parameter to 1.