Mission coordination versus navigation
WCS may request transport and track results, while fleet management and robot controllers own assignment, traffic and navigation as designed. Assign priority, vehicle selection, charging and obstruction handling explicitly. Avoid two layers owning the same decision.
An accepted mission may wait for a robot, load or destination access. Online robot count is not immediate mission capacity. Model waiting reasons.
Interface compatibility
Keep mission, load and transfer-point identifiers stable. Define cancellation, updates and partial completion. If considering VDA 5050, verify versions and implemented features on both sides. It addresses robot-to-fleet-control communication, not an automatic ready-made WCS connector.
Vendor APIs need the same semantic care. A successful HTTP response may only acknowledge receipt. Logistics completion requires the agreed delivery condition.
Technical reference: VDA 5050 — Mobile robot / fleet control interface.
Robot-to-equipment transfer
Arrival at a station does not prove load transfer. The handshake combines positioning, destination readiness, identity and transfer confirmation. Local safety functions remain in the appropriate equipment architecture.
Reserve destinations before missions can obstruct stations or routes. Define waiting, authorized alternatives or exceptions when the destination fails. Changes must preserve traceability and business authority.
Worked incomplete-handoff scenario
The robot reports arrival at E4 but the conveyor has not received the carton. Keep the task in transfer. After an interruption, compare load presence and acknowledged state on both sides before repeating any action.
Test communication loss, insufficient battery for a new mission and blocked destinations. Separate resource waiting, travel and handoff times. Acceptance concerns coherent load delivery, not a moving robot icon.
Project verification criteria
- Separate WCS mission ownership from fleet navigation.
- Verify version and implemented standardized-interface features.
- Distinguish arrival from completed load transfer.
Examples describe engineering decisions and test scenarios. Implemented interfaces, limits and features are defined by each project’s scope.