Vehicle Direction Detection

Vehicle Direction Detection

Aim:

Creating a Simulink Data Dictionary and Simulink model for Vehicle Direction Detection system.

Overview:

Identifying the direction of the vehicle is one of the important & diverse features in Autonomous driving & Advanced Driver Assistance Features. This particular sub-feature of identifying the direction of the vehicle is basically identifying the direction the vehicle is taking based on the camera input.

The camera reads the road signs & stores them into its memory with unique values for a left turn, right turn & straight drive. Depending on the direction it is taking, the final indication is given to the driver – as an indication if he is driving in the recommended direction or not.

Vehicle Direction Determination can also be coupled alongside features like GPS systems to identify whether the vehicle is reaching its destination in an optimized manner. This sub-feature can also be used along with Lane Detection, Highway Warning, Ramp Entry / Exit in Wrong Way Detection, etc.

Objective:

1. Development of MATLAB Simulink model as per requirement.
2. Tag the requirements to the Simulink model; tagging requirements 1 & requirement 2 to their corresponding subsystems is fine.
3. MBD compliant changes, Data Dictionary creation

Requirement:

Requirement - 1:

• Steering wheel input as yaw rate (Signal name: SteeringWheel_YawDegreeInput) is the input for this system.
• This is compared against 3 angular values, one each for a left turn, right turn & straight drive (Calibration Values: Right_Turn_AngularLimit, Left_Turn_AngularLimit, Straight_Drive_Steering_Angle) to say which specific direction the steering wheel is turning towards.
• Use switch blocks to compare & develop this requirement. Keep this requirement in a subsystem & the output of this requirement is a local signal (Signal Name: Vehicle_Turn_Status).

Requirement – 2:

• Keep this requirement as a separate subsystem. Inputs to this requirement are a local signal from requirement 1 (Signal Name: Vehicle_Turn_Status) & an input signal from the camera (Signal Name: CameraInput_RoadSign), which confirms the occurrence of a road sign.
• Signal Vehicle_Turn_Status is compared against calibration values (Calibration Values: RightTurn_RoadSign, LeftTurn_RoadSign, Straight_RoadSign), if each of them is found equal, then each of the three corresponding output is compared against the camera input signal,
• Using a logical operator block, only one among them is finally given as output signal (Signal Name: Vehicle_Direction_Indicator).

Signals & Calibration Data List:

Signal / Calibration Name	Signal Type	Data Type	Dimension	Min	Max	Initial Value	Units
SteeringWheel_YawDegreeInput	Input	Int16	1	-180	180	-	Deg
CameraInput_RoadSign	Input	Boolean	1	0	1	-	-
Vehicle_Turn_Status	Local	Int16	1	-180	180	-	Deg
Right_Turn_AngularLimit	Calibration	Int16	[1 1]	-180	180	30	Deg
Left_Turn_AngularLimit	Calibration	Int16	[1 1]	-180	180	-120	Deg
Straight_Drive_Steering_Angle	Calibration	Int16	[1 1]	-180	180	0	Deg
RightTurn_RoadSign	Calibration	Int16	[1 1]	-180	180	30
LeftTurn_RoadSign	Calibration	Int16	[1 1]	-180	180	-120
Straight_RoadSign	Calibration	Int16	[1 1]	-180	180	0
Vehicle_Direction_Indicator	Output	Boolean	1	0	1	-	-

Procedure:

First, the Simulink Data Dictionary is created from the given Signal and Calibration Data List.

For that under the Model properties, we will create a Data Dictionary and make the file. The Signals and Calibration are added as per the requirement and then accordingly, we fill the data.

Fig: SLDD file for Vehicle Direction Detection

Then we create a subsystem with the input as SteeringWheel_YawDegree & CameraInput_RoadSign and output as Vehicle_Direction_Indicator.

Fig: Main Subsystem for Vehicle Direction Detection

Under the subsystem, two subsystems are created.

From, the first subsystem we implement the given requirement. The SteeringWheel_YawDegree is taken as an input and accordingly, we give the output as Vehicle_Turn_Status. The use of a switch block is done to fulfill the given requirement.

Fig: Representation of the first subsystem

The following is the representation of the first subsystem:

Fig: Model of the first subsystem

Then we create the second subsystem, which will take the output of the first subsystem Vehicle_Turn_Status and CameraInput_RoadSign as input.

The output of this subsystem is the Vehicle_Direction_Indicator.

Fig: Model of the second subsystem

Then under the second subsystem, we make use of a conditional block to get the result. Comparing every Road sign, we will get which turn the vehicle is taking. Whether it is left, right, or straight turn.

Fig: Representation inside the second subsystem

Then the output of these is compared with the Camera input, which gives the direction to the vehicle.

The following is the model of the subsystem with the required input and output.

Fig: Model inside the main subsystem

The following is the Simulink Model of Vehicle Detection System

Fig: Simulink Model for Vehicle Direction Detection

Conclusion:

Created a Simulink Data Dictionary file and Simulink model for Vehicle Direction Detection system.