Go to CAV-TEC V2.0 Data Types

Definition
Functional Requirements
Syntax
Semantics
Conformance
Performance

1 Definition

Wheel Command is a Data Type representing a steering command directed to a specific wheel of the Connected Autonomous Vehicle, including the desired angle, steering mode, rate limits, control profile, safety limits, and health awareness information.

2 Functional Requirements

A Wheel Command instance shall include:

  • The identifier of the wheel being commanded.
  • The desired steering angle.

A Wheel Command instance may include:

  • The steering mode.
  • The maximum allowed steering rate.
  • A multi-phase steering control profile.
  • Safety limits including maximum torque, current, and mechanical stop warning.
  • Health awareness information including thermal derating, load estimate, and calibration status.

3 Syntax

https://schemas.mpai.community/CAV2/V2.0/data/WheelCommand.json

4 Semantics

Table 1 specifies the semantics of the Wheel Command Data Type.

Table 1 – Semantics of the Wheel Command Data Type

Label Type Req. Description
Header string (CAV-WHC-V2.0) Yes Wheel Command Header – Standard CAV-WHC-Vx.y.
MInstanceID string Identifier of the M-Instance (Virtual Space) associated with this Wheel Command instance.
UEnvironmentID string Identifier of the U-Environment (Real Space) associated with this Wheel Command instance.
WheelCommandID string Yes Unique identifier of this Wheel Command instance.
WheelID string Yes Identifier of the wheel being commanded.
WheelCommandTime Simple Time Yes Time this Wheel Command instance was produced.
WheelCommand object Yes Set of steering command parameters.
WheelCommand.Angle number Yes Desired steering angle in degrees (-90 to +90).
WheelCommand.SteeringMode string Steering mode. One of: ManualAssist, SteerByWire, ActiveSteering, EmergencyOverride, Calibration.
WheelCommand.SteeringRateLimit number Maximum allowed steering rate in degrees per second.
WheelCommand.ControlProfile[] object [] Optional multi-phase steering envelope.
WheelCommand.ControlProfile[].Phase string Yes Phase of the steering envelope. One of: ramp-up, hold, ramp-down.
WheelCommand.ControlProfile[].Duration number Yes Phase duration in seconds.
WheelCommand.ControlProfile[].Angle number Target steering angle for this phase in degrees.
WheelCommand.ControlProfile[].SteeringRate number Steering rate for this phase in degrees per second.
WheelCommand.SafetyLimits object Safety constraints for the steering actuator.
WheelCommand.SafetyLimits.MaxTorque number Maximum allowed actuator torque.
WheelCommand.SafetyLimits.MaxCurrent number Maximum allowed actuator current.
WheelCommand.SafetyLimits.MechanicalStopWarning boolean Indicates proximity to the mechanical steering stop.
WheelCommand.HealthAwareness object Health and condition information of the steering actuator.
WheelCommand.HealthAwareness.ThermalDerating boolean Indicates whether thermal derating is active.
WheelCommand.HealthAwareness.LoadEstimate number Estimated load on the steering actuator.
WheelCommand.HealthAwareness.CalibrationRequired boolean Indicates whether calibration of the steering actuator is required.
DataXMData Data Exchange Metadata MPAI-PTF Data Exchange Metadata providing provenance, authorisation, legal, security, and confidence information associated with this Wheel Command instance in a trusted data exchange context.
DescrMetadata string Human-readable descriptive metadata of the Wheel Command instance (plain text, max 2048 characters).

5 Conformance Testing

Data conform to the Wheel Command 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.

6 Performance Assessment