Challenge

Project 1- Traffic Jam Assistant Feature

DDaniel Dsa9 Dec 2021

Aim of the project:

To develop one specific requirement of Traffic Jam Assistant algorithm which would predominantly feature in the Instrument Panel Cluster (IPC) algorithm.

Objective of the project:

The model is developed in MATLAB Simulink as per Model Based Design (MBD) guidelines.
Code Generation Profile is using Embedded Coder.
Simulink Data Dictionary is created for the model and is linked to the model.
Model Advisor Report is checked, followed by code generation for the developed model.

Introduction to the Feature:

Traffic Jam Assistant is one of the most common feature in Advanced Driver Assistance System. Traffic Jam Assistant helps the driver arrive more relaxed at their destination, even in dense traffic or in traffic jams. As a partially automated comfort function, the system takes over the longitudinal & lateral guidance of the vehicle. This means that the car can drive off, accelerate & brake automatically, as well as steer the vehicle within certain constraints. The driver has to permanently supervise the system & be ready to take over the complete control of the vehicle at any time.

Traffic Jam Assistant system helps to avoid rear end collisions in dense traffic conditions & traffic jams. In Traffic jams, the vehicle takes over driving off, acceleration, braking and steering within same lane.

Basic Working Principle:

Traffic Jam Assistant is based on the sensors and the functionality of the Adaptive Cruise Control (ACC) with stop & go and Lane Keeping Support (LKS). When ACC ‘Stop & Go’ is turned ON, the Traffic Jam Assistant continuously analyses the speed of the surrounding vehicles and compares it with the own driving speed. If the system detects dense traffic or a traffic jam at speeds less than 60 kmph, the driver can activate the functionality by press of a button. The vehicle will now automatically follow the vehicle in front, takes over driving off, acceleration, braking and steering within same lane.

Information regarding the Traffic Jam Assistant will be available to be displayed to the driver in the Instrument Panel Cluster (IPC). The Algorithm which the students need to implement here in this project is predominantly based on IPC units.

Development of the model for Traffic Jam Assistant:

One specific requirement of Traffic Jam Assistant algorithm is developed which would predominantly feature in the Instrument Panel Cluster (IPC) algorithm. It is to be noted that the whole Traffic Jam Assistant is a huge algorithm and only one small part of the logic is implemented here. The idea is to familiarize with concepts of Model Based Development in MATLAB Environment. The model is implemented according to the following requirements:

List of Input, Local, Output signals and Calibration values:

Input Signals:

Name of the Signal	Data Type	Range
Input_Voltage	uint8	0 - 255
Input_Switch	boolean	0 – 1
Enable_Display	uint8	0 - 255

Output Signal:

Name of the Signal	Data Type	Range
Output_Display	uint8	0 - 255

Calibration Signals:

Name of the Signal	Data Type	Range	Initial Value
VOLTAGE_MINIMUM_RANGE	uint8	0 – 255	30
VOLTAGE_MAXIMUM_RANGE	uint8	0 – 255	50
OFF_MODE	uint8	0 – 255	2
ON_MODE	uint8	0 – 255	1
STANDBY_MODE	uint8	0 – 255	3
INTERRUPT_1	boolean	0 – 1	1
INTERRUPT_2	boolean	0 - 1	1
NO_DISPLAY	uint8	0 – 255	0

Local Signal:

Name of the Signal	Data Type	Range
Optimum_Voltage	boolean	0 - 1

Requirement No 1:

Input Signal “Input_Voltage” is compared against voltage values “VOLTAGE_MINIMUM_RANGE” & “VOLTAGE_MAXIMUM_RANGE”.
Incoming input signal “Input_Voltage” must be greater than – equal to “VOLTAGE_MINIMUM_RANGE” and less than – equal to “VOLTAGE_MAXIMUM_RANGE”.
Output signal from here is “Optimum_Voltage” which will be one of the inputs to the subsystem “DisplayUnit”.

Figure 1: Traffic_Jam_Assist Subsystem

Figure 2: Requirement1 subsystem

Requirement No 2 (DisplayUnit Subsystem):

Input Signals are “Optimum_Voltage”, “Input_Switch”,“Enable_Display”. Signal “Enable_Display” must be saturated between the range 0 – 7. Output signal from the subsystem is “Output_Display”.
Input Signal “Enable_Display” is compared against pre – defined set of values in a multiport switch. Total data ports in the multiport switch is 5.
Multiport switch inputs 1 & 2 is connected to calibration signal “ON_MODE”, Multiport switch inputs 3 & 4 is connected to calibration signal “OFF_MODE” while Multiport switch input 5 is connected to calibration signal “STANDBY_MODE”.
The output from Multiport switch is connected to the first input port of the Switch block. The third input port of the Switch block is connected to the calibration signal “NO_DISPLAY”.
Meanwhile NOT value of input signal “Input_Switch” is compared in an AND gate against input signal “Optimum_Voltage” and the output from comparing if calibration signals “INTERRUPT_1” & “INTERRUPT_2” are equal. The output of the AND gate is the second input of the switch block.
The output from the switch block is “Output_Display”.

Figure 3: Requirement1 and DisplayUnit (Requirement-2) subsystem

Figure 4: DisplayUnit (Requirement No 2) subsystem

Simulink Data Dictionary (SLDD) file:

A Simulink Data Dictionary (SLDD) file is made which contains all the input, output, localisable signals and calibration values used in the model.

Steps to create SLDD:

Under Modeling tab in Simulink, select the option ‘Link to Data Dictionary’ . The file name for the SLDD is specified and a new SLDD is created.

Figure 5: Simulink Data Dictionary (SLDD) creation

Figure 6: SLDD for the model

Solver and Code generation settings:

The solver type is chosen as ‘Fixed Step’ with ‘Discrete (No Continuous States)’. The fixed step size (sample time) for the solver is specified as 0.01 .

Figure 7: Solver settings under Model Configuration Parameters

For code generation, the system target file is chosen as ‘ert.tlc’

Figure 8: Code generation settings under Model Configuration parameters

Model Advisor Check:

A model advisor check is performed to check that there are no errors in model design and the model conforms to the ‘Mathworks Automotive Advisory Board’ (MAAB) guidelines.

Figure 9: Model Advisor Report (MAAB) guidelines check

Figure 10: Code Generation Report

Generated C-Code:

/*

 * File: TrafficJamAssist_MBD.c

 *

 * Code generated for Simulink model 'TrafficJamAssist_MBD'.

 *

 * Model version                  : 1.6

 * Simulink Coder version         : 9.6 (R2021b) 14-May-2021

 * C/C++ source code generated on : Wed Dec  8 18:49:36 2021

 *

 * Target selection: ert.tlc

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

 * Code generation objectives: Unspecified

 * Validation result: Not run

 */



#include "TrafficJamAssist_MBD.h"

#include "TrafficJamAssist_MBD_private.h"



/* Real-time model */

static RT_MODEL_TrafficJamAssist_MBD_T TrafficJamAssist_MBD_M_;

RT_MODEL_TrafficJamAssist_MBD_T *const TrafficJamAssist_MBD_M =

  &TrafficJamAssist_MBD_M_;



/* Model step function */

void TrafficJamAssist_MBD_step(void)

{

  /* local block i/o variables */

  boolean_T Optimum_Voltage;



  /* Logic: '<S3>/AND' incorporates:

   *  Constant: '<S3>/Constant'

   *  Constant: '<S3>/Constant1'

   *  Inport: '<Root>/Input_Voltage'

   *  RelationalOperator: '<S3>/Relational Operator'

   *  RelationalOperator: '<S3>/Relational Operator1'

   */

  Optimum_Voltage = ((Input_Voltage >= VOLTAGE_MINIMUM_RANGE) && (Input_Voltage <=

    VOLTAGE_MAXIMUM_RANGE));



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

   *  Constant: '<S2>/Constant4'

   *  Constant: '<S2>/Constant5'

   *  Inport: '<Root>/Input_Switch'

   *  Logic: '<S2>/AND'

   *  Logic: '<S2>/NOT'

   *  RelationalOperator: '<S2>/Relational Operator'

   */

  if (Optimum_Voltage && (!Input_Switch) && (INTERRUPT_1 == INTERRUPT_2)) {

    uint8_T tmp;



    /* Saturate: '<S2>/Saturation' incorporates:

     *  Inport: '<Root>/Enable_Display'

     */

    if (Enable_Display <= 7) {

      tmp = Enable_Display;

    } else {

      tmp = 7U;

    }



    /* End of Saturate: '<S2>/Saturation' */



    /* MultiPortSwitch: '<S2>/Multiport Switch' */

    switch (tmp) {

     case 1:

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

       *  Constant: '<S2>/Constant'

       */

      Output_Display = ON_MODE;

      break;



     case 2:

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

       *  Constant: '<S2>/Constant'

       */

      Output_Display = ON_MODE;

      break;



     case 3:

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

       *  Constant: '<S2>/Constant1'

       */

      Output_Display = OFF_MODE;

      break;



     case 4:

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

       *  Constant: '<S2>/Constant1'

       */

      Output_Display = OFF_MODE;

      break;



     default:

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

       *  Constant: '<S2>/Constant2'

       */

      Output_Display = STANDBY_MODE;

      break;

    }



    /* End of MultiPortSwitch: '<S2>/Multiport Switch' */

  } else {

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

     *  Constant: '<S2>/Constant3'

     */

    Output_Display = NO_DISPLAY;

  }



  /* End of Switch: '<S2>/Switch' */

}



/* Model initialize function */

void TrafficJamAssist_MBD_initialize(void)

{

  /* (no initialization code required) */

}



/* Model terminate function */

void TrafficJamAssist_MBD_terminate(void)

{

  /* (no terminate code required) */

}



/*

 * File trailer for generated code.

 *

 * [EOF]

 */

Conclusion:

The model is developed in MATLAB Simulink for implementing a specific portion of ‘Traffic Jam Assistant’ feature as per Model Based Design (MBD) guidelines.
Simulink Data Dictionary is created for the model and is linked to the model.
Model Advisor Report is checked, followed by code generation using embedded coder for the developed model.

Project 1- Traffic Jam Assistant Feature

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Ship work like this
in your own course.