A software update that changes obstacle detection algorithms is considered a "significant modification." You must re-run verification tests. Clause 5.4 – "Modifications and repairs."
Purchase the current ISO 3691-4:2023 PDF from your national standards body, and incorporate its requirements into your next AGV/AMR project from concept to commissioning. Iso 3691-4 Pdf
ISO 3691-4 does not replace risk assessment; it references it. You must document: A software update that changes obstacle detection algorithms
and Autonomous Mobile Robots (AMRs) . Automated Forklift Trucks and tuggers. Iso 3691-4 Pdf
A core requirement is the ability of the truck to detect personnel and avoid collisions.
Having the PDF on a hard drive is not compliance. Here is a practical roadmap for facility managers.