CAV-TEC V1.0 AIWs Motion Actuation Subsystem

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1       Functions

2       Reference Model

3       I/O Data

4       Functions of AI Modules

5       I/O Data of AI Modules

6      AUW, AIMs, and JSON

7       AI Modules

8       Data Types

1        Functions of Motion Actuation Subsystem

The Motion Actuation Subsystem:

1. Transmits spatial and environmental information gathered from its sensors and mechanical subsystems to the Environment Sensing Subsystem (ESS).
2. Receives AMS-MAS Message from the Autonomous Motion Subsystem (AMS).
3. Translates AMS-MAS Message into specific Commands to its own mechanical subsystems, e.g., Brakes, Steering, and Motors.
4. Receives Responses from its mechanical subsystems.
5. Packages Responses into MAS-AMS Messages.
6. Sends MAS-AMS Messages to Autonomous Motion Subsystem, possibly containing a Road State.

2        Reference Architecture of Motion Actuation Subsystem

Figure 1 represents the Motion Actuation Subsystem Reference Model.

Figure 1 – Motion Actuation Subsystem Reference Model

The operation of the Motion Actuation Subsystem unfolds as follows:

1. “Other Environment Data” are transferred to the ESS.
2. MAS Spatial Attitude Generation computes the Ego CAV Spatial Attitude Attitude using Odometer, Speedometer, and Accelerometer and sends it to ESS.
3. AMS Command Interpreter interprets AMS-MAS Messages received from AMS and issues commands to Motors, Wheel, and Brakes.
4. MAS Response Analyser interprets the responses received from Motors, Wheel, and Brakes and sends MAS-AMS Messages to to AMS.

3        I/O Data of Motion Actuation Subsystem

Table 1 gives the input/output data of Motion Actuation Subsystem.

Table 1 – I/O data of Motion Actuation Subsystem

Input	Comments
Odometer	Provides distance data.
Speedometer	Provides instantaneous velocity.
Accelerometer	Provides instantaneous acceleration.
Other Environment data	Other environment data, e.g., humidity, pressure, temperat­ure.
AMS-MAS Message	High-level motion command.
Wheel Motor Response	Forces wheels rotation, gives feedback.
Steering Wheel Response	Moves wheels by an angle, gives feedback.
Brake Response	Acts on brakes, gives feedback.
Output	Comments
Spatial Attitude	Position, Orientation and their velocity and acceleration vectors.
Other Environment data	Environment data such as humidity, pressure, temperat­ure.
Wheel Motor Command	Forces wheels rotation, gives feedback.
Steering Wheel Command	Moves wheels by an angle, gives feedback.
Brakes Command	Acts on brakes, gives feedback.
MAS-AMS Message	Feedback from MAS Response Analyser during and after AMS-MAS Message ex­ecution.

4        Functions of Motion Actuation Subsystem’s AI Modules

Table 2 gives the AI Modules of Autonomous Motion Subsystem.

Table 2 – Functions of Motion Actuation Subsystem’s AI Modules

AIM	Function
Spatial Attitude Generation	Computes Ego CAV’s Spatial Attitude using odometer, speedometer, and accelerometer data.
AMS Command Interpreter	Receives, analyses, and actuates AMS-MAS Message into specific commands to Brakes, Steering Wheels, and Wheel Motors.
MAS Response Analyser	Receives and analyses responses from Brakes, Steering Wheel, and Wheel Motors. Assembles and forwards the MAS-AMS Response to AMS.

5        I/O Data of Motion Actuation Subsystem’s AI Modules

Table 3 gives, for each AIM (1^st column), the input data (2^nd column) from which AIM (column) and the output data (3^rd column).

Table 3 – I/O Data of Motion Actuation Subsystem’s AI Modules

AIM	Input	Output
MAS Spatial Attitude Generation	– Odometer – Speedometer – Accelerometer	– Spatial Attitude
AMS Command Interpretation	– AMS-MAS Message	– Brake Command – Motor Command – Steering Command
MAS Response Analysis	– Brake Response – Motor Response – Steering Response	– MAS-AMS Message

6     AIW, AIMs, and JSON

7     AI Modules

An initial version of the MAS AI Modules is available.

8      Data Types

An initial version of the MAS Data Types is available.