Project 2-Highway Assistant-Lane Changing Assistant

Project – Highway Assistant-Lane Changing Assistant

Aim:

To develop one specific requirement of Highway Assistant – Lane Changing Assistant algorithm which is an ADAS Feature using MATLAB and Simulink and make our model MAAB Compliant and generate code using AUTOSAR coder.

Objective:

• Model must be developed in MATLAB Simulink per MBD guidelines.
• Code Generation Profile must be Autosar Coder.
• Simulink Data Dictionary must be created for the model & must be linked to the model.
• All the input & output signals must be mapped into the Autosar Editor.
• Generate model advisor report and code.

Highway Assistant – Lane Changing Assistant:

The Highway Assistant supports the driver and takes over the longitudinal and lateral guidance of the vehicle in monotonous driving situations on highways. The partially automated function can automatically start, accelerate, brake as well as steer the vehicle to a certain extent. The driver has to permanently supervise the system and be ready to take over the complete control of the vehicle at any time.

Drivers are taught to assess surrounding traffic before changing lanes by checking their rearview and side mirrors and looking over each shoulder. However, even for those who follow this sequence of checks, the vehicle's blind spot – the area alongside and just behind the vehicle – is a constant source of danger and often the cause of serious accidents. Even vehicles approaching quickly from behind can pose a risk. To make changing lanes safer, this feature has been developed.

Basic Working Principle:

Highway Assistant is a partially automated driving function for a speed range of up to 180 km/h (112 mph) on highways. It combines the radar-based longitudinal guidance of Adaptive Cruise Control (ACC) with the video-based lateral guidance of lane keeping support in one system. Highway Assistant can be supplemented by an automatic lane change initiated and monitored by the driver in a speed range of 60 – 130 km/h (35 – 80 mph).

The lane Change Assistant works by using two mid-range radar sensors that are concealed in the rear bumper – one on the left, one on the right. These two sensors monitor the area alongside and behind the car. Powerful control software collates the sensor information to create a complete picture of all traffic in the area behind the vehicle. Whenever another vehicle approaches at speed from behind or is already present in the blind spot, a signal such as a warning light in the side mirror alerts the driver to the hazard. Should the driver still activate the turn signal with the intention of changing lanes, the system issues an additional acoustic and/or haptic warning.

Main subsystem Lane_Change_Assistance:

Lane_Change_Assistance subsystem:

The subsystem Lane_Change_Assistance consists of three subsystem inside it which are defined according to the requirement document. They are:

• Requirement1[Highway_DisplayUnit]
• Requirement2[Lane_DisplayUnit]
• Requirement3[Display_ModeUnit]

Requirement No 1 [Highway_DisplayUnit]:

Inputs to this particular subsystem are “Highway_Input_Signal”, “Enable_Display”, “Input_Switch”. These three input signals, when assigned to a particular value will give output signals of specific value. The output signals are “Highway_Display_Mode_1”, “Highway_Display_Mode_2”, “Highway_Display_Mode_3”, “Highway_Display_Mode_4”. The requirement must be implemented in the form of a Stateflow logic.

Condition	Action
Highway_Input_Signal = 1 Enable_Display = off Input_Switch = on	Highway_Display_Mode_1 = 232 Highway_Display_Mode_2 = 183 Highway_Display_Mode_3 = 41 Highway_Display_Mode_4 = 94
Highway_Input_Signal = 1 Enable_Display = on Input_Switch = on	Highway_Display_Mode_1 = 213 Highway_Display_Mode_2 = 183 Highway_Display_Mode_3 = 9 Highway_Display_Mode_4 = 94

Stateflow chart of requirement1

Inside the chart of requirement 1:

Requirement No 2 [Lane_DisplayUnit]:

Inputs to this particular subsystem are “Enable_Display”, “Input_Switch”, “Lane_Input_Signal”. These three input signals, when assigned to a particular value will give output signals of specific value. The output signals are “Lane_Display_Mode_1”, “Lane_Display_Mode_2”, “Lane_Display_Mode_3”, “Lane_Display_Mode_4”. The requirement must be implemented in the form of Stateflow logic.

Condition	Action
Lane_Input_Signal= 6 Enable_Display = off Input_Switch = on	Lane_Display_Mode_1 = 132 Lane_Display_Mode_2 = 185 Lane_Display_Mode_3 = 54 Lane_Display_Mode_4 = 67
Lane_Input_Signal= 6 Enable_Display = on Input_Switch = on	Lane_Display_Mode_1 = 127 Lane_Display_Mode_2 = 248 Lane_Display_Mode_3 = 186 Lane_Display_Mode_4 = 84

Inside the chart containing Requirement No 2 [Lane_DisplayUnit]:

Requirement No 3 [Display_ModeUnit]:

Signals coming from both subsystems “Highway_Display_Mode_1” & “Lane_Display_Mode_1” are given as inputs to a switch block which will have input signal “Highway_Input_Signal” given as 2^nd input to the switch block. Corresponding output from this particular switch block is output signal “Display_Mode_1”.

Signals coming from both subsystems “Highway_Display_Mode_2” & “Lane_Display_Mode_2” are given as inputs to a switch block which will have input signal “Highway_Input_Signal” given as 2^nd input to the switch block. Corresponding output from this particular switch block is output signal “Display_Mode_2”.

Signals coming from both subsystems “Highway_Display_Mode_3” & “Lane_Display_Mode_3” are given as inputs to a switch block which will have input signal “Highway_Input_Signal” given as 2^nd input to the switch block. Corresponding output from this particular switch block is output signal “Display_Mode_3”.

Signals coming from both subsystems “Highway_Display_Mode_4” & “Lane_Display_Mode_4” are given as inputs to a switch block which will have input signal “Highway_Input_Signal” given as 2^nd input to the switch block. Corresponding output from this particular switch block is output signal “Display_Mode_4”.

Sldd:

To create sldd go to modelling→link to data dictionary and the following window is opened. To create a new sldd select new and enter the file name and apply the changes.

This will take you to the model explorer window and there all the signals are defined as shown below. In Autosar Software Component we need not provide storage class individually for input, output, and calibrating signals. Every signal mentioned in this data dictionary is kept with auto as storage class.

Simulink data dictionary:

In order to do AUTOSAR compliant generation in model configurations parameters, the configuration parameter for solver is fixed step and no continuous states. The max step size has to be set as auto as shown below.

The system target file present inside the code generation settings must be autosar.tlc

After completing these configuration settings you need to create the AUTOSAR software component environement.

Apps→ code generation → AUTOSAR Component designer is selecter.

The autosar dictionary is selected from the tab in the left corner called “Code Mapping-AUTOSAR SW component”. Select that option and inside that select the autosar dictionary.

Inside autosar dictionary we need to configure XML OPTIONS, S-R Interaces, Runnables , Sender and Receiver ports.

1. XML Options:

This is to set path files to the make the model Autosar SW compliant the paths are set for all the given options using the /filename/path name.

Also the internal data constrains need to be checked for exports.

2. S-R Interfaces:

The interfaces for the Inputs(Receiver) and the outputs(Sender) is mapped here . Each consists of a data element and they are also mapped inside SR interfaces

Data elements inside each SR interface:

Similar to the picture shown below all data elements are mapped to the respective interfaces.

3. Runnables:

The runnables are the initial file and the timing files which are required by most of the models. Since the model complexity is not high in our case we can use init file alone. The mapping of init file to the autosar dictionary is shown below.

4. Port Mappings:

Sender ports:

The output ports are the sender ports and these should contain the prefix Pp_. The syntax for mapping the outport in this sender ports: Pp_portname.

Receiver ports:

The output ports are the sender ports and these should contain the prefix Pp_. The syntax for mapping the outport in this sender ports: Pp_portname.

Next is validation process:

Refresh the model and proceed with validation .

Once the validation is succeeded the inports and the outports are configured with the corresponding interface blocks as shown below.

Inports configuration:

Outports configuration:

Signal Resolving and propogation:

This should be done after creating sldd and building the model. The signal name is selected and set to resolve. Resolving is done for the first time. When even there is a signal appearing for the first time in the model the signal is resolved. For the next subsequent appearances those signals are propagated.

Usage: to prevent inhibition of garbage values and causing error.

After the inport and outport configuration the model is checked for MAAB GUIDELINES.

Once the report is generated the model proceeds for code generation.

Single screen shot of the report is shown here. Refer the attachment below for the full advisor report.

Code Generation:

Go to autosar → Quick start → welcome page select next →

Systems→ select model name and proceed with next → output→select C code compliant with AUTOSAR and single instant →next

System configurations will be shown proceed with next

The parameter and the model settings that need to be configured will be shown and ask for changes in order to generate code. Accept and proceed with code generation.

The window is displayed after the completion of generated code. Select finish and go to your model where the code is generated.

A screen shot of the generated code is attached below. The run time environment files are created as shown below. In autosar code generation you have .arxml files.

Code generation report:

Code:

/*
 * File: Highway_lane_assistant.c
 *
 * Code generated for Simulink model 'Highway_lane_assistant'.
 *
 * Model version                  : 1.28
 * Simulink Coder version         : 9.5 (R2021a) 14-Nov-2020
 * C/C++ source code generated on : Fri Feb  4 12:51:45 2022
 *
 * Target selection: autosar.tlc
 * Embedded hardware selection: Intel->x86-64 (Windows64)
 * Code generation objectives:
 *    1. Execution efficiency
 *    2. RAM efficiency
 * Validation result: Not run
 */

#include "Highway_lane_assistant.h"

/* Named constants for Chart: '<S3>/Chart' */
#define IN_Display_OFF                 ((uint8)1U)
#define IN_Display_ON                  ((uint8)2U)

/* Block signals and states (default storage) */
DW rtDW;

/* Model step function */
void Lane_Change_Assistance_Step(void)
{
  sint32 tmp;
  uint8 rtb_Highway_Display_Mode_1;
  uint8 rtb_Highway_Display_Mode_3;
  uint8 rtb_Lane_Display_Mode_1;
  uint8 rtb_Lane_Display_Mode_2;
  uint8 rtb_Lane_Display_Mode_3;
  uint8 rtb_Lane_Display_Mode_4;

  /* Chart: '<S3>/Chart' incorporates:
   *  Inport: '<Root>/Enable_Display'
   *  Inport: '<Root>/Highway_Input_Signal'
   *  Inport: '<Root>/Input_Switch'
   */
  if (rtDW.is_active_c3_Highway_lane_assis == 0U) {
    rtDW.is_active_c3_Highway_lane_assis = 1U;
    rtDW.is_c3_Highway_lane_assistant = IN_Display_OFF;
    rtb_Highway_Display_Mode_1 = 232U;
    rtb_Highway_Display_Mode_3 = 41U;
  } else if (rtDW.is_c3_Highway_lane_assistant == IN_Display_OFF) {
    rtb_Highway_Display_Mode_1 = 232U;
    rtb_Highway_Display_Mode_3 = 41U;
    if ((Rte_IRead_Lane_Change_Assistance_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Enable_Display_DE_Enable_Display
         () == 1) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Input_Switch_DE_Input_Switch()
         == 1)) {
      rtDW.is_c3_Highway_lane_assistant = IN_Display_ON;
      rtb_Highway_Display_Mode_1 = 213U;
      rtb_Highway_Display_Mode_3 = 9U;
    }
  } else {
    /* case IN_Display_ON: */
    rtb_Highway_Display_Mode_1 = 213U;
    rtb_Highway_Display_Mode_3 = 9U;
    if ((Rte_IRead_Lane_Change_Assistance_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Enable_Display_DE_Enable_Display
         () == 0) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Input_Switch_DE_Input_Switch()
         == 1)) {
      rtDW.is_c3_Highway_lane_assistant = IN_Display_OFF;
      rtb_Highway_Display_Mode_1 = 232U;
      rtb_Highway_Display_Mode_3 = 41U;
    }
  }

  /* End of Chart: '<S3>/Chart' */

  /* Chart: '<S4>/Chart' incorporates:
   *  Inport: '<Root>/Enable_Display'
   *  Inport: '<Root>/Input_Switch'
   *  Inport: '<Root>/Lane_Input_Signal'
   */
  if (rtDW.is_active_c1_Highway_lane_assis == 0U) {
    rtDW.is_active_c1_Highway_lane_assis = 1U;
    rtDW.is_c1_Highway_lane_assistant = IN_Display_OFF;
    rtb_Lane_Display_Mode_1 = 132U;
    rtb_Lane_Display_Mode_2 = 185U;
    rtb_Lane_Display_Mode_3 = 54U;
    rtb_Lane_Display_Mode_4 = 67U;
  } else if (rtDW.is_c1_Highway_lane_assistant == IN_Display_OFF) {
    rtb_Lane_Display_Mode_1 = 132U;
    rtb_Lane_Display_Mode_2 = 185U;
    rtb_Lane_Display_Mode_3 = 54U;
    rtb_Lane_Display_Mode_4 = 67U;
    if ((Rte_IRead_Lane_Change_Assistance_Step_Rp_Lane_Input_Signal_DE_Lane_Input_Signal
         () == 6) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Enable_Display_DE_Enable_Display
         () == 1) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Input_Switch_DE_Input_Switch()
         == 1)) {
      rtDW.is_c1_Highway_lane_assistant = IN_Display_ON;
      rtb_Lane_Display_Mode_1 = 127U;
      rtb_Lane_Display_Mode_2 = 248U;
      rtb_Lane_Display_Mode_3 = 186U;
      rtb_Lane_Display_Mode_4 = 84U;
    }
  } else {
    /* case IN_Display_ON: */
    rtb_Lane_Display_Mode_1 = 127U;
    rtb_Lane_Display_Mode_2 = 248U;
    rtb_Lane_Display_Mode_3 = 186U;
    rtb_Lane_Display_Mode_4 = 84U;
    if ((Rte_IRead_Lane_Change_Assistance_Step_Rp_Lane_Input_Signal_DE_Lane_Input_Signal
         () == 6) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Enable_Display_DE_Enable_Display
         () == 0) &&
        (Rte_IRead_Lane_Change_Assistance_Step_Rp_Input_Switch_DE_Input_Switch()
         == 1)) {
      rtDW.is_c1_Highway_lane_assistant = IN_Display_OFF;
      rtb_Lane_Display_Mode_1 = 132U;
      rtb_Lane_Display_Mode_2 = 185U;
      rtb_Lane_Display_Mode_3 = 54U;
      rtb_Lane_Display_Mode_4 = 67U;
    }
  }

  /* End of Chart: '<S4>/Chart' */

  /* Switch: '<S2>/Switch' incorporates:
   *  Inport: '<Root>/Highway_Input_Signal'
   *  Switch: '<S2>/Switch1'
   *  Switch: '<S2>/Switch2'
   */
  tmp =
    Rte_IRead_Lane_Change_Assistance_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
    ();
  if (tmp > 0) {
    /* Outport: '<Root>/Display_Mode_1' */
    Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_1_DE_Display_Mode_1
      (rtb_Highway_Display_Mode_1);
    rtb_Lane_Display_Mode_2 = 183U;
  } else {
    /* Outport: '<Root>/Display_Mode_1' */
    Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_1_DE_Display_Mode_1
      (rtb_Lane_Display_Mode_1);
  }

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

  /* Outport: '<Root>/Display_Mode_2' */
  Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_2_DE_Display_Mode_2
    (rtb_Lane_Display_Mode_2);

  /* Switch: '<S2>/Switch2' incorporates:
   *  Switch: '<S2>/Switch3'
   */
  if (tmp > 0) {
    /* Outport: '<Root>/Display_Mode_3' */
    Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_3_DE_Display_Mode_3
      (rtb_Highway_Display_Mode_3);
    rtb_Lane_Display_Mode_4 = 94U;
  } else {
    /* Outport: '<Root>/Display_Mode_3' */
    Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_3_DE_Display_Mode_3
      (rtb_Lane_Display_Mode_3);
  }

  /* Outport: '<Root>/Display_Mode_4' */
  Rte_IWrite_Lane_Change_Assistance_Step_Pp_Display_Mode_4_DE_Display_Mode_4
    (rtb_Lane_Display_Mode_4);
}

/* Model initialize function */
void Lane_Change_Assistance_Init(void)
{
  /* (no initialization code required) */
}

/*
 * File trailer for generated code.
 *
 * [EOF]
 */

Conclusion:

A model is developed in MATLAB Simulink for implementing the specific operation of highway assistant lane changing feature as per the MBD guidelines. Also the Simulink data dictionary is created and linked with the model. All the input and output signals are used in the development are mapped to the corresponding interfaces in the autosar dictionary.

Finally the model advisor is done and code also has been generated.