Robot Model Handover: Read Links and Joints Precisely

A robot description package can arrive with a rendered assembly and a list of familiar component names. That picture is helpful, but a robot model handover still needs a shared vocabulary for the declarations inside the file. In particular, a link name and a joint relationship answer different questions. This glossary-based acceptance discussion uses an imaginary software delivery. It includes no physical robot dimensions, movement procedure or claim that a model has been validated against hardware.

Ask which part of the description a label names

Begin with one label from the supplier's model documentation and ask where it appears in the delivered package. Is it the name of a link, a joint or an informal caption in a rendered view? Retain the supplier's actual identifier rather than replacing it with a translated description in the evidence record. A readable explanation can sit beside the identifier without losing the connection to the file.

For the fictional delivery, a reviewer sees the word wrist on a picture and in a model listing. That resemblance creates a question, not an established mapping. Ask the supplier to point to the declaration meant by the caption. The answer may be simple, but recording it prevents later reviewers from treating a convenient illustration label as if it were necessarily a machine-readable identifier.

Read a joint as an expressed relationship

The urdfdom repository's proposed schema for the original URDF format defines named link elements and joint declarations with required parent and child elements. This is a specific source artifact, explicitly marked as a proposal in its header. It helps locate the distinction in that model vocabulary; it is not a complete guarantee of what every parser or extended format accepts.

Ask the supplier which parent and child are declared for the joint under discussion and how those names relate to the delivered model. Do not infer the relationship solely from what overlaps in the rendered picture. An acceptance note can record that the declaration was located while leaving a separate question about whether it represents the intended assembly. Those are different review conclusions and should not be collapsed into model approved.

Keep relationship names apart from numerical conventions

Once the declaration is located, the buyer may need to understand numerical values associated with the description. ROS REP 103 states an SI unit convention and calls for exceptions to be justified and documented. Use that reference when discussing material that actually claims to follow the ROS convention, rather than silently imposing assumptions on an unrelated model format.

A glossary entry should explain which quantity a value describes and where the relevant unit convention is declared. Naming a joint does not answer those questions. If a supplier adds a diagram annotation in another unit, request the intended relationship to the delivered value instead of editing the model to match the annotation. This review concerns interpretation of supplied documents, not altering equipment parameters.

The same discipline applies to copied excerpts. A paragraph containing a value can lose its original convention when pasted into a separate handover sheet. Ask that the sheet retain enough reference information for a reader to recover the source meaning. Do not invent a conversion or a physical limit merely because a spreadsheet has an empty cell waiting to be filled.

Record a glossary question at the right level

A useful question identifies the exact term, its source location and the explanation still requested. For example, the reviewer may have located the declared relationship but not the supplier's intended mapping to the assembly drawing. Another question may concern the convention for a numerical annotation. Keeping those entries separate lets the supplier answer one without appearing to resolve the other automatically.

When a revised package is delivered, check whether the response addresses the same declaration. A renamed label can require an updated explanation even if the rendered image looks unchanged. Preserve the earlier question and the supplied response so that the acceptance record shows how the interpretation developed. This is more useful than replacing every older note with a new image and losing the unresolved context.

Close the terminology review without overclaiming

The final note should identify the terms and relationships explained, the applicable numerical conventions and any questions that remain. Locating declarations does not demonstrate physical accuracy, mechanical condition or safe motion. Those conclusions need their own authorized review and evidence. No parser test or hardware comparison has been conducted for the present article.

Our two original illustrations show a reading method rather than a real robot structure. They deliberately omit dimensions and model-specific identifiers. The robot terminology collection covers related distinctions, while the article directory offers other handover topics. A precise glossary helps buyers ask for the missing explanation instead of accepting a familiar picture as the entire description.