Project 1

Mini Project on Vehicle Direction Detection

Abhishek Anil Patil | 25/05/2022

General 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 vehicle is basically identifying the direction the vehicle is taking based on the camera input.

Camera reads the road signs & stores into its memory with unique values for left turn, right turn & straight drive. Depending on the direction it is taking, 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.

Objective of Mini Project:

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 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

Simulink model

The vehicle_direction_detection subsystem has 2 inputs - SteeringWheel_YawDegreeInput and CameraInput_RoadSign.

Its output is Vehicle_Direction_Indicator

SLDD file creation

The following signals and parameters are defined in a SLDD file as per the table given below

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	-	-

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 & output of this requirement is a local signal (Signal Name: Vehicle_Turn_Status).

If SteeringWheel_YawDegreeInput is positive, Right_Turn_AngularLimit is given to output.

Else if SteeringWheel_YawDegreeInput is zero, Left_Turn_AngularLimit is given to output.

Else, Straight_Drive_Steering_Angle is given to output.

This logic is modelled using switch blocks as shown above.

Requirement – 2:

• Keep this requirement as a separate subsystem. Inputs to this requirement are local signal from requirement 1 (Signal Name: Vehicle_Turn_Status) & an input signal from 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).

If Vehicle_Turn_Status and RightTurn_RoadSign are equal, true vale is given to AND block along with CameraInput_RoadSign.

If Vehicle_Turn_Status and LeftTurn_RoadSign are equal, true value is given to AND block along with CameraInput_RoadSign.

If Vehicle_Turn_Status and Straight_RoadSign are equal, true value is given to AND block along with CameraInput_RoadSign.

The logic mentioned above is modelled using relational operators and AND block and switch blocks as shown above.

Output is combined using a MUX block; hence the output signal dimension is changed to 3.

Requirement tagging

Make sure that the word file is in the same working folder

Select the text that you want to tag

Right-click a model object and select Requirements.

MAB check

In model advisor, only select the following.

After running the check

We got 7 warnings and no fails

Click on generate report.

The generated report(.html) is included in the attachments.

Code generation

Go to APPS > embedded coder

After opening embedded coder, click on build.

This will generate a c code for the model

The entire code is pasted below

vehicle_direction_detection.c

/*


 * File: vehicle_direction_detection.c


 *


 * Code generated for Simulink model 'vehicle_direction_detection'.


 *


 * Model version                  : 1.24


 * Simulink Coder version         : 9.5 (R2021a) 14-Nov-2020


 * C/C++ source code generated on : Wed May 25 11:19:36 2022


 *


 * Target selection: ert.tlc


 * Embedded hardware selection: Intel->x86-64 (Windows64)


 * Code generation objectives: Unspecified


 * Validation result: Not run


 */





#include "vehicle_direction_detection.h"


#include "vehicle_direction_detection_private.h"





/* Exported data definition */





/* Definition for custom storage class: ExportToFile */


boolean_T Vehicle_Direction_Indicator[3];/* '<S3>/Signal Conversion' */





/* Const memory section */


/* Definition for custom storage class: Const */


const int16_T LeftTurn_RoadSign = -120;/* Referenced by: '<S3>/Constant1' */


const int16_T Left_Turn_AngularLimit = -120;/* Referenced by: '<S2>/Constant1' */


const int16_T RightTurn_RoadSign = 30; /* Referenced by: '<S3>/Constant' */


const int16_T Right_Turn_AngularLimit = 30;/* Referenced by: '<S2>/Constant' */


const int16_T Straight_Drive_Steering_Angle = 0;/* Referenced by: '<S2>/Constant2' */


const int16_T Straight_RoadSign = 0;   /* Referenced by: '<S3>/Constant2' */





/* Real-time model */


static RT_MODEL_vehicle_direction_de_T vehicle_direction_detection_M_;


RT_MODEL_vehicle_direction_de_T *const vehicle_direction_detection_M =


  &vehicle_direction_detection_M_;





/* Model step function */


void vehicle_direction_detection_step(void)


{


  /* local block i/o variables */


  int16_T Vehicle_Turn_Status;





  /* Outputs for Atomic SubSystem: '<Root>/Vehicle_direction_detection' */


  /* Switch: '<S2>/Switch' incorporates:


   *  Constant: '<S4>/Constant'


   *  Constant: '<S5>/Constant'


   *  Inport: '<Root>/SteeringWheel_YawDegreeInput'


   *  RelationalOperator: '<S4>/Compare'


   *  RelationalOperator: '<S5>/Compare'


   *  Switch: '<S2>/Switch1'


   */


  if (SteeringWheel_YawDegreeInput > 0) {


    /* Switch: '<S2>/Switch' incorporates:


     *  Constant: '<S2>/Constant'


     */


    Vehicle_Turn_Status = Right_Turn_AngularLimit;


  } else if (SteeringWheel_YawDegreeInput == 0) {


    /* Switch: '<S2>/Switch1' incorporates:


     *  Constant: '<S2>/Constant2'


     *  Switch: '<S2>/Switch'


     */


    Vehicle_Turn_Status = Straight_Drive_Steering_Angle;


  } else {


    /* Switch: '<S2>/Switch' incorporates:


     *  Constant: '<S2>/Constant1'


     *  Switch: '<S2>/Switch1'


     */

Test harness (MIL/SIL)

For creatin a SIL test harness,

The subsystem has to be defined as an atomic subsystem.

The model solver settings should be changed to fixed step solver with no continuous steps. The sample time should be 0.01 seconds as per requirements.

The system target file should be ert.tlc for embedded coder

Right click on the subsystem and select test harness

For MIL test use normal verification mode

For SIL test use software-in-loop verification mode

Test cases

Test cases must be created to perform MIL/SIL tests

Simulation Time	SteeringWheel_YawDegreeInput	CameraInput_RoadSign	Right_Turn	Left_Turn	Straight
0	30	1	1	0	0
1	30	1	1	0	0
1	-120	1	0	1	0
2	-120	1	0	1	0
2	0	1	0	0	1
3	0	1	0	0	1
3	50	0	0	0	0
4	50	0	0	0	0

The SteeringWheel_YawDegreeInput can take 3 types of values – positive zero and negative, which are then compared with CameraInput_RoadSign to give the above three outputs.

The fourth value represents any random value.

Test harness model

The test case values are imported into the signal builder

A DEMUX is used to separate the output signal into its constituent parts.

These are the actual outputs which are subtracted from the expected outputs taken from the signal builder.

The scope shows this error signal

As the error signal is zero, we can conclude that the model has passed the MIL/SIL test.