A positioning requirement becomes usable when both teams can identify what will be measured, in which configuration and how the result will be judged. Keep the planned positioning error budget as a design input, then write a separate acceptance record for the assembled handoff.
“Accurate enough for the instrument” leaves several questions unanswered. Does the requirement concern the tool before release, the seated labware after release, or both? Which station reference defines the target? Does the test include another docking cycle? Close these questions before selecting a convenient measurement method.
Define the condition being accepted
Identify the labware and its loaded condition, tool revision, receiving fixture and relevant software or configuration versions. Record which axes and orientations matter to the receiving station. Use units beside each limit and name the physical references used to establish it.
Keep approach clearance, placement geometry and final seating as distinct review items. A placement measurement does not by itself close every access or release question. Bring those dependencies into the mobile manipulator platform review before freezing the test configuration.
For each test, state what is reset between trials. Repeating a motion from one fixed setup examines a different condition from moving away, docking again and repeating the transfer. Agree the relevant conditions and trial count for the project; this worksheet supplies no universal sample size or tolerance.
Write the measurement and decision method
Name the measuring equipment, reference setup and recorded outputs. Ask the responsible engineer to establish the measurement uncertainty and document how it affects the acceptance decision. Set that decision rule before reviewing the results, including what happens when the available evidence cannot support an unambiguous decision.
For reporting background, NIST TN 1297 explains that a measurement result should identify its uncertainty and how that uncertainty was evaluated. When expanded uncertainty is reported, its coverage factor is also reported. This is measurement guidance; it does not set the robot's allowable error or a project pass/fail rule. NIST TN 1297, section 7, 1994 edition
Positioning acceptance worksheet
| Record item | Entry to agree before testing |
|---|---|
| Test identity | Test ID, revision, owner, witness and date |
| Requirement source | Approved drawing/specification and revision |
| Accepted condition | Before release, after seating, or separately defined checks |
| Reference and axes | Physical datum, coordinate directions, units and orientation convention |
| Configuration | Platform, tool, fixture, labware, load and configuration revisions |
| Limits | Requirement for each relevant measured quantity and whether it applies to individual trials or an agreed summary statistic; no assumed default |
| Test sequence | Start condition, movement, docking/reset conditions and agreed trial count |
| Measurement method | Equipment, setup, calibration/status records and raw data format |
| Uncertainty and decision rule | Evaluation reference, treatment near a limit and release authority |
| Observed results | Raw-data references and agreed summary; deviations kept visible |
| Exceptions | Interference, incomplete seating, interruption or other unexpected behavior |
| Release record | Accepted, rejected or unresolved; actions, owners and signed decision |
Keep design estimates and test results separate
If a predicted contribution was based on a supplier document or an assumption, preserve that basis. When assembled-platform data becomes available, record the tested configuration and explain what the result covers. Do not relabel an untested estimate as a measured result.
Use the hardware FAT guide to place this worksheet in the acceptance package. The quality and traceability review helps identify which build and revisions the evidence belongs to.
After a change to the tool, fixture, labware or station, identify which acceptance conditions may be affected. Let the authorized engineering review determine the checks to repeat and record that decision. For an OEM hardware enquiry, include the accepted condition, proposed measurement method and unresolved decisions in your non-confidential project brief.