Project 1 (Mini Project on Vehicle Direction Detection

AIM: To create a Simulink model for vehicle direction determination:

Genereal 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 along - side 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.

Objectives:

1. Development of MATLAB Simulink model as per requirement.
2. Tag the requirements to the Simulink model; tagging requirement 1 & requirement 2 to their corresponding subsystems is fine.
3. MBD compliant changes, Data Dictionary creation & code generation is added advantage, and that is not the scope of this project.
4. If choosing code generation, Storage class for Input signals: ImportedExtern; Storage class for Output signal: Export to File; Storage class for local signals: localizable; Storage class for calibration signals: Const.
5. Choose sample time for all signals as 0.01s

Blocks used in this model:

• Relational operator
• Switch
• Constant block
• Logical operator
• From & go to tag scope.

General requirements to build this model:

In this model, there are two requirements provided so I have to build my model with respect to the requirements.

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 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 outputs is compared against the camera input signal,
• Using a logical operator block, only one among them is finally given as the output signal (Signal Name: Vehicle_Direction_Indicator).

Test cases:

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	-	-

Model :

• To explain this Simulink model by step by step process.
• Create the ssld file to update the variables.
• Design a model based on the requirements.
• To do the SIL & MIL test and explain the process.
• To test the model in MAB guidance and try to rectify the errors.

Step-1

• To Create a sldd file to update all the given inputs, outputs & parameters on this file later calling these variables on the Simulink blocks are shown in the fig.

Step-2 Resolve and propagation:

• In this case, we have updated our signals inputs in the sldd file so we have to add the signal into the connection lines to get the proper output.
• So, we have used the resolve and propagation method on this model

Steps to get resolve and propagate signals.

• once right-click the line a popup window can be opened select properties option to open the resolve and propagate option.
• 
• 

• In that window, we may type the required input signals which is updated in the ssld file and select the propagate option to propagate the signal.

Step-3

Model explanation:

• First I can create two sub-systems and name as requirement-1 & requirement-2

Requirement-1 subsystem:

• 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 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).

• As per the requirements, 1 can design this model, when the steering yaw degree is considered as input is connected to the relational operator and the relational operator is connected with the switch based on the if-else condition the switch is given the output as a boolean number.
• For eg if I'm given -120 deg as input means when the relation operator checks the given input once it fails means its automatically switch the false statement when the false statement is connected to the left-turn_drive so the the switch given the output the left-turn value.

Requirment:2 Subsystem:

• 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 outputs is compared against the camera input signal,
• Using a logical operator block, only one among them is finally given as the output signal (Signal Name: Vehicle_Direction_Indicator).
• 
• As per requirement statement-2 i have to compare the vehicle turn status and the camera sign once is true means the vehicle can conclude the turn is based on the road sign.
• So, i have to taken the vehicle turn status as input and it would be given to the relational operator which is the road sign is compared with the vehicle turn status.
• and i use the and gate which is used to given the any one output to the mux at a time for if left turn status is true means right turn and straight turn will be fale so that's why I'm using the And gate in this subsytem.
• The basic objective of the subsystem is to comape the vehicle turn status with the road sign.

Step-4 Generating codes without SIL testing process:

• After completion of the model we have generate the required code without Done the SIL test.
• Select the apps option which is available on the top the Simulink window then select the embedded code option to generate the code are shown below.

We are able to run the model with no errors and the outputs are as expected.

Output:

The SteeringWheel_YawDegreeInput can vary between -180 to 180 degrees.

When it checks,

• if the input steering value is less than 0, it shows left.
• if the input steering value is greater than 0, it shows Right.
• If the input steering value is 0, then it shows straight.

The output is Signal Vehicle_Turn_Status

Signal Vehicle_Turn_Status is compared against calibration values (RightTurn_RoadSign, LeftTurn_RoadSign, Straight_RoadSign) using AND block.

If each of them is equal, then the three corresponding outputs are compared against the camera input signal using a logical operator.

Attached Simulink file, SLDD file, and other related files for reference.