Go To CAV-TEC V1.0 Use Cases and Functional Requirements home page

 

1       Functions of Motion Actuation Subsystem

2       Reference Architecture of Motion Actuation Subsystem

3       I/O Data of Motion Actuation Subsystem

4       Functions of Motion Actuation Subsystem’s AI Modules

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

6       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.
  2. Receives AMS-MAS Message from the Autonomous Motion Subsystem.
  3. Translates AMS-MAS Message into specific Commands to its own mechanical subsystems, e.g., Brakes, Steering Wheel, and Wheel Motors.
  4. Receives Responses from its mechanical subsystems.
  5. Packages Responses into an MAS-AMS Message.
  6. Sends MAS-AMS Messages to Autonomous Motion Subsystem.
  7. During the execution, the MAS may send MAS-AMS Message containing a Road State.

2        Reference Architecture of Motion Actuation Subsystem

Figure 8 – Motion Actuation Subsystem Reference Model

Figure 8 represents the Motion Actuation Subsystem Reference Model.

The operation of the Motion Actuation Subsystem unfolds as follows:

  1. Other Environment Data are transferred to the Environment Sensing Subsystem.
  2. MAS Spatial Attitude Generation sends to Environment Sensing Subsystem the Ego CAV Spatial Attitude computed using Odometer, Speedometer, and Accelerometer.
  3. AMS Command Interpreter interprets AMS-MAS Messages received from Autonomous Motion Subsystem and issues commands to Wheel Motors, Steering Wheel, and Brakes.
  4. MAS Response Analyser interprets the responses received from Wheel Motors, Steering Wheel, and Brakes and sends MAS-AMS Responses to the Autonomous Motion Subsystem.

3        I/O Data of Motion Actuation Subsystem

Table 15 gives the input/output data of Motion Actuation Subsystem.

Table 15 – 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 16 gives the AI Modules of Autonomous Motion Subsystem.

Table 16 – 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 17 gives, for each AIM (1st column), the input data (2nd column) from which AIM (column) and the output data (3rd column).

Table 17 – 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
– Wheel Motor Command
– Steering Wheel Command
MAS Response Analysis – Brake Response
– Steering Wheel Response
– Wheel Motor Response
– MAS-AMS Message

6        Data Types

An initial version of the MAS Data Types is available.