Definition
Functional Requirements
Syntax
Semantics
Conformance
Performance
1 Definition
Wheel States is a Data Type enumerating the operational states of a wheel steering actuator of the Connected Autonomous Vehicle.
2 Functional Requirements
Wheel States shall represent the following actuator states:
- Normal – steering actuator operating normally and following commands within expected tolerance.
- Hold – actuator holding the wheel at its current angle.
- ActiveSteering – actuator actively controlling the wheel angle in response to commands.
- Released – wheel released with minimal assistive torque applied.
- Stuck – wheel cannot move as commanded; mechanical or servo obstruction.
- MechanicalStopReached – wheel angle reached mechanical end-stop; no further movement allowed.
- Overheated – actuator temperature exceeds rated thermal limits; performance derated.
- Degraded – reduced operational capability due to subsystem constraints or partial fault.
- Fault – general actuator or sensor fault requiring inspection or fallback mode.
- Unavailable – steering actuator unavailable (offline, in maintenance, or non-responsive).
- Calibration – actuator performing calibration or alignment procedures.
- SelfTest – actuator performing startup or periodic diagnostics.
- DeratedThermal – thermal derating active due to excessive actuator temperature.
- DeratedLoad – derating active due to high mechanical or steering rack load.
- SensorFault – fault detected in wheel angle, encoder, or feedback sensors.
- CommunicationFault – communication between steering controller and actuator is impaired.
- LowPower – insufficient power supply to support nominal steering behavior.
- EmergencyOverride – emergency logic temporarily overrides actuator control for safety.
3 Syntax
https://schemas.mpai.community/CAV2/V2.0/data/WheelStates.json
4 Semantics
Table 1 specifies the semantics of the Wheel States Data Type.
| Value |
|---|
| Normal |
| Hold |
| ActiveSteering |
| Released |
| Stuck |
| MechanicalStopReached |
| Overheated |
| Degraded |
| Fault |
| Unavailable |
| Calibration |
| SelfTest |
| DeratedThermal |
| DeratedLoad |
| SensorFault |
| CommunicationFault |
| LowPower |
| EmergencyOverride |
5 Conformance Testing
Data conform to the Wheel States Data Type when they validate against its schema. If the schema references other schemas, data referencing a secondary schema shall also validate against that schema, if present, and conform with the Qualifier, if present.
