CAV-ARC V1.1 AIWs Motion Actuation Subsystem

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       Reference Software	8       Conformance Testing	9     Performance Assessment

1        Functions of Motion Actuation Subsystem

The Motion Actuation Subsystem (MAS):

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 Data and sends it to ESS.
3. AMS Command Interpretation interprets AMS-MAS Messages received from AMS and issues commands to Motors, Wheel, and Brakes.
4. MAS Response Analysis 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
Spatial Data	Provides distance data.
Weather Data	Data such as humidity, pressure, temperat­ure.
AMS-MAS Message	High-level motion command.
Motor Response	Forces wheel rotation, Motor gives gives feedback.
Wheel Response	Moves wheel by an angle, Wheel gives feedback.
Brake Response	Acts on brake, Brake gives feedback.
Output	Comments
Spatial Attitude	Position, Orientation and their velocity and acceleration vectors.
Weather Data	Data such as humidity, pressure, temperat­ure, and ice.
Motor Command	Forces wheels rotation, gives feedback.
Wheel Command	Moves wheels by an angle, gives feedback.
Brake Command	Acts on brakes, gives feedback.
AMS-MAS Message	Feedback from MAS Response Analysis 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 Interpretation	Receives, analyses, and actuates AMS-MAS Message into specific commands to Brakes, Steering Wheels, and Wheel Motors.
MAS Response Analysis	Receives and analyses responses from Brakes, Steering Wheel, and Wheel Motors. Assembles and forwards the MAS-AMS Response to AMS.
Ice Condition Analysis	Adds ice condition information to the input Weather Data.

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
Spatial Attitude Generation	– Spatial Data	– Spatial Attitude
AMS Command Interpretation	– AMS-MAS Message	– Brake Command – Motor Command – Wheel Command
MAS Response Analysis	– Brake Response – Motor Response – Wheel Response	– AMS-MAS Message
Ice Condition Analysis	– Brake Response – Motor Response – Wheel Response – Weather Data	– Weather Data

6     AIW, AIMs, and JSON

AIW	AIMs	AIM Names	JSON
CAV-MAS		Motion Actuation Subsystem	X
	CAV-MSG	Spatial Attitude Generation	X
	CAV-ACI	AMS Command Interpretation	X
	CAV-MRA	MAS Response Analysis	X
	CAV-ICA	Ice Condition Analysis	X

7     Reference Software

 

8      Conformance Testing

 

9     Performance Assessment