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Definition
Functional Requirements
Syntax
Semantics
Conformance Testing
Performance Assessment

1      Definition

A Message sent by:

  1. The AMS to the MAS requesting it to move the CAV along the specified Trajectory.
  2. The MAS to the AMS informing it about the execution of the last AMS‑MAS Message.

2      Functional Requirements

The AMS‑MAS Message sent by the AMS to the MAS contains:

  • Trajectory – the path to be executed.
  • Command – one of the following Actions:
    • Execute: execute the Trajectory, changing the CAV’s Spatial Attitude SAA at time tA to Spatial Attitude SAB at time tB.
    • Suspend: temporarily stop executing the current Trajectory.
    • Resume: continue execution of the suspended Trajectory.
    • Change: replace the current Trajectory with a new one.

When receiving an AMS‑MAS Message, the MAS implements the requested Action and may issue a series of AMS‑MAS Messages at intermediate Positions containing:

  • CurrentTime – the current Time.
  • CAV Spatial Attitude – estimated from MAS‑internal sensors.
  • Road State – reported when significant divergence between expected and actual Spatial Attitude is detected (e.g., Ice Conditions, Submersion).
  • CAV State – current functional state of the CAV.

These updates inform the AMS about the progress of executing the AMS‑MAS Message.

3      Syntax

https://schemas.mpai.community/CAV2/V1.1/data/AMSMASMessage.json

4      Semantics

Table 1 – Semantics of the AMS‑MAS Message Data Type

Label
Description
Header AMS‑MAS Message Header – Standard “CAVCAV‑MSM#8209;AMM‑Vx.y”.
MInstanceID Identifier of the M-Instance (Virtual Space) associated with this AMS‑MAS Message.
UEnvironmentID Identifier of the U-Environment (Real Space) associated with this AMS‑MAS Message.
AMSMASMessageID Unique identifier of this AMS‑MAS Message instance.
AMSMASMessageTime Time this AMS‑MAS Message was produced.
AMSMASMessageSpaceTime Time this AMS‑MAS Message was sent.
AMSMessage Data in message from AMS to MAS.
    – Trajectory Trajectory to be executed by the MAS.
    – Command Command to apply to the current Trajectory: “Execute”, “Suspend”, “Resume”, or “Change”.
MASMessage Data in message from MAS to AMS.
    – CurrentTime Current Time at which this MAS Message was produced.
    – SpatialAttitude CAV Spatial Attitude estimated from MAS‑internal sensors.
    – RoadState Road State reported when significant divergence between expected and actual Spatial Attitude is detected.
    – CAVState Current functional state of the CAV.
DataXMData MPAI-PTF Data Exchange Metadata providing provenance, authorisation, legal, security, and confidence information associated with this AMS‑MAS Message in a trusted data exchange context.
DescrMetadata Human-readable descriptive metadata of the AMS‑MAS Message (plain text, max 2048 characters).

5      Conformance Testing

A Data instance conforms with AMS‑MAS Message (CAVCAV‑MSM#8209;AMM) if:

  1. The Data validates against the AMS‑MAS Message’s JSON Schema.
  2. All Data in the AMS‑MAS Message’s JSON Schema:
    1. Have the specified type.
    2. Validate against their JSON Schemas.
    3. Conform with their Data Qualifiers.

6      Performance Assessment

Not part of this specification.

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