Highway Assistant-Lane Changing Assistant

                                                                                                   Highway Assistant-Lane Changing Assistant

Aim:

Model Development of a feature of Highway Assistant-Lane Changing Assistant using MATLAB and Simulink as per MAAB guidelines, producing Model Advisor Report as well as generating Code using AUTOSAR Coder.

Objective:

• Model Development in MATLAB Simulink as per MAAB guidelines.
• Code Generation using Autosar Coder.
• Creation of Simulink Data Dictionary.
• Mapping all the input & output signals into the Autosar Editor.
• Generating Model Advisor Report.

Highway Assistant – Lane Changing Assistant:

Introduction to the Feature

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.

Fig: Lane Changing Assistant

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.

Calibration and Signal Data List:

Input Signals:

Local Signals:

Output Signals:

Requirements:

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 a 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.

 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 a 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.

 Requirement No 3:

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. The corresponding output from this particular switch block is the 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. The corresponding output from this particular switch block is the 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. The corresponding output from this particular switch block is the 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. The corresponding output from this particular switch block is the output signal “Display_Mode_4”.

Procedure:

The first step is the creation of the Simulink Data Dictionary File from the given calibration and signal data list.

Fig: Simulink Data Dictionary for Lane Changing Assistant Feature

As per the first requirement, the first subsystem will have three inputs. They are Highway_Input_Signal, Enable_Display, and Input_Switch.

Fig: Subsystem for Highway_DisplayUnit

The input further goes to the chart. The chart will have the output as Highway_Display_Mode_1, Highway_Display_Mode_2, Highway_Display_Mode_3, and Highway_Display_Mode_4

Fig: Chart for Highway_DisplayUnit

Inside the chart, we will implement Highway_Input_Signal, Enable_Display, and Input_Switch using AND blocks. The output is given in the State.

Fig: Stateflow logic for Highway_DisplayUnit

Once the Stateflow logic is written, we will resolve the port for input and output.

Fig: Resolved Signal for Highway_DisplayUnit

As per requirement 2, we will enable the subsystem using Lane_Input_Signal for a value of 6. Input for the block will be Input_Switch and Enable_display.

Fig: Subsystem for Lane_DisplayUnit

These inputs will further go to Chart, where the Stateflow logic will be written. The output of the chart are Lane_Display_Mode_1, Lane_Display_Mode_2, Lane_Display_Mode_3, Lane_Display_Mode_4.

Fig: Chart for Lane_DisplayUnit

Inside the chart, the Enable_Display and Input_Switch are used to make logic for Lane Display output.

The main output is written inside the State for Lane_Display_Mode.

Fig: Stateflow logic for Lane_DisplayUnit

The input and output signals are then resolved.

Fig: Resolved Signal for Lane_DisplayUnit

Once this is done we will propagate the signals to the output. Then the output of Highway_Way_Mode and Lane_Display_Mode are provided to the suitable output port.

Fig: Output of Highway_DisplayUnit and Lane_DisplayUnit

The output of the Highway_Display_Mode and Lane_Display_Mode are provided to the Switch block. That is in total 4 switch blocks are used. The conditional input signal is taken as Highway_Input_Signal for all the blocks.

Fig: Display_Mode output

Fig: Algorithm of Highway Assistant-Lane Changing Assistant

To give a better look we will put all this in a single subsystem. For better visualization, we will mask the subsystem with the appropriate image.

Fig: Final Model of Highway Assistant-Lane Changing Assistant

Then we will make the model in compliance with the AUTOSAR. So, all the input & output signals will be mapped into the Autosar Editor.

But prior to that, we will set the System target file as autosar.tlc

We will make sure that in Solver we will set the solver to Fixed-Step.

Fig: Code Generation Setting

Then under App, we will select the AUTOSAR component.

This will open Code Mapping - AUTOSAR SW Component.

For the Reciever port of the model, that is input, we will rename the port with the prefix Rp_.

Fig: RecieverPorts of the model

For the Sender port of the model, that is output, we will rename the port with the prefix Pp_.

Fig: SenderPorts of the model

For the S-R Interfaces of the model, we will rename the port with the prefix SRIf_.

Fig: S-R Interfaces of the model

For the Data Elements of the model, we will rename the port with the prefix DE_.

Fig: Data Element of the model

Then we will validate the model for AUTOSAR Compliance.

Fig: AUTOSAR Validation

Once the mapping is done we will check for Model Advisor.

Then after a successful check, we will Generate a Code.

Fig: Generated C Code for the Model

The following is the complete Generated C Code for the Model:

/*
 * File: Highway_Assistant_Lane_Changing_Assistant.c
 *
 * Code generated for Simulink model 'Highway_Assistant_Lane_Changing_Assistant'.
 *
 * Model version                  : 4
 * Simulink Coder version         : 9.3 (R2020a) 18-Nov-2019
 * C/C++ source code generated on : Sat Mar 13 01:03:10 2021
 *
 * Target selection: autosar.tlc
 * Embedded hardware selection: Intel->x86-64 (Windows64)
 * Code generation objectives: Unspecified
 * Validation result: Not run
 */

#include "Highway_Assistant_Lane_Changing_Assistant.h"
#include "Highway_Assistant_Lane_Changing_Assistant_private.h"

/* Named constants for Chart: '/Chart' */
#define Highway_Assistan_IN_Condition_1 ((uint8)1U)
#define Highway_Assistan_IN_Condition_2 ((uint8)2U)

/* Block signals (default storage) */
B_Highway_Assistant_Lane_Chan_T Highway_Assistant_Lane_Changi_B;

/* Block states (default storage) */
DW_Highway_Assistant_Lane_Cha_T Highway_Assistant_Lane_Chang_DW;

/* Model step function */
void Highway_Assistant_Lane_Changing_Assistant_Step(void)
{
  sint32 rtb_Highway_Display_Mode_1;
  sint32 rtb_Highway_Display_Mode_3;
  float64 tmp;
  float64 tmp_0;

  /* Chart: '/Chart' incorporates:
   *  Inport: '/Enable_Display'
   *  Inport: '/Highway_Input_Signal'
   *  Inport: '/Input_Switch'
   */
  if (Highway_Assistant_Lane_Chang_DW.is_active_c3_Highway_Assistant_ == 0U) {
    Highway_Assistant_Lane_Chang_DW.is_active_c3_Highway_Assistant_ = 1U;
    if ((Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1.0) &&
        (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Enable_Display_DE_Enable_Display
         () == 1.0) &&
        (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Input_Switch_DE_Input_Switch
         () == 1.0)) {
      Highway_Assistant_Lane_Chang_DW.is_c3_Highway_Assistant_Lane_Ch =
        Highway_Assistan_IN_Condition_2;
      rtb_Highway_Display_Mode_1 = 213;
      rtb_Highway_Display_Mode_3 = 9;
    } else {
      Highway_Assistant_Lane_Chang_DW.is_c3_Highway_Assistant_Lane_Ch =
        Highway_Assistan_IN_Condition_1;
      rtb_Highway_Display_Mode_1 = 232;
      rtb_Highway_Display_Mode_3 = 41;
    }
  } else if (Highway_Assistant_Lane_Chang_DW.is_c3_Highway_Assistant_Lane_Ch ==
             Highway_Assistan_IN_Condition_1) {
    rtb_Highway_Display_Mode_1 = 232;
    rtb_Highway_Display_Mode_3 = 41;
  } else {
    /* case IN_Condition_2: */
    if ((Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1.0) &&
        (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Enable_Display_DE_Enable_Display
         () == 0.0) &&
        (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Input_Switch_DE_Input_Switch
         () == 1.0)) {
      Highway_Assistant_Lane_Chang_DW.is_c3_Highway_Assistant_Lane_Ch =
        Highway_Assistan_IN_Condition_1;
      rtb_Highway_Display_Mode_1 = 232;
      rtb_Highway_Display_Mode_3 = 41;
    } else {
      rtb_Highway_Display_Mode_1 = 213;
      rtb_Highway_Display_Mode_3 = 9;
    }
  }

  /* End of Chart: '/Chart' */

  /* Outputs for Enabled SubSystem: '/Lane_Display_Mode' incorporates:
   *  EnablePort: '/Enable'
   */
  /* RelationalOperator: '/Compare' incorporates:
   *  Constant: '/Constant'
   *  Inport: '/Lane_Input_Signal'
   */
  if (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Lane_Input_Signal_DE_Lane_Input_Signal
      () == 6.0) {
    /* Chart: '/Lane_Display_Mode' incorporates:
     *  Inport: '/Enable_Display'
     *  Inport: '/Input_Switch'
     */
    if (Highway_Assistant_Lane_Chang_DW.is_active_c1_Highway_Assistant_ == 0U) {
      Highway_Assistant_Lane_Chang_DW.is_active_c1_Highway_Assistant_ = 1U;
      Highway_Assistant_Lane_Chang_DW.is_c1_Highway_Assistant_Lane_Ch =
        Highway_Assistan_IN_Condition_1;
      Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1 = 132.0;
      Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2 = 185.0;
      Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3 = 54.0;
      Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4 = 67.0;
    } else if (Highway_Assistant_Lane_Chang_DW.is_c1_Highway_Assistant_Lane_Ch ==
               Highway_Assistan_IN_Condition_1) {
      if ((Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Enable_Display_DE_Enable_Display
           () == 1.0) &&
          (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Input_Switch_DE_Input_Switch
           () == 1.0)) {
        Highway_Assistant_Lane_Chang_DW.is_c1_Highway_Assistant_Lane_Ch =
          Highway_Assistan_IN_Condition_2;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1 = 127.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2 = 248.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3 = 186.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4 = 84.0;
      } else {
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1 = 132.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2 = 185.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3 = 54.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4 = 67.0;
      }
    } else {
      /* case IN_Condition_2: */
      if ((Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Enable_Display_DE_Enable_Display
           () == 0.0) &&
          (Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Input_Switch_DE_Input_Switch
           () == 1.0)) {
        Highway_Assistant_Lane_Chang_DW.is_c1_Highway_Assistant_Lane_Ch =
          Highway_Assistan_IN_Condition_1;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1 = 132.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2 = 185.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3 = 54.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4 = 67.0;
      } else {
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1 = 127.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2 = 248.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3 = 186.0;
        Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4 = 84.0;
      }
    }

    /* End of Chart: '/Lane_Display_Mode' */
  }

  /* End of RelationalOperator: '/Compare' */
  /* End of Outputs for SubSystem: '/Lane_Display_Mode' */

  /* Switch: '/Switch' incorporates:
   *  Inport: '/Highway_Input_Signal'
   *  Switch: '/Switch1'
   *  Switch: '/Switch2'
   *  Switch: '/Switch3'
   */
  tmp_0 =
    Rte_IRead_Highway_Assistant_Lane_Changing_Assistant_Step_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
    ();
  if (tmp_0 > 0.0) {
    tmp = rtb_Highway_Display_Mode_1;
  } else {
    tmp = Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_1;
  }

  /* End of Switch: '/Switch' */

  /* Outport: '/Display_Mode_1' */
  Rte_IWrite_Highway_Assistant_Lane_Changing_Assistant_Step_Pp_Display_Mode_1_DE_Display_Mode_1
    (tmp);

  /* Switch: '/Switch1' */
  if (tmp_0 > 0.0) {
    tmp = 183.0;
  } else {
    tmp = Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_2;
  }

  /* Outport: '/Display_Mode_2' */
  Rte_IWrite_Highway_Assistant_Lane_Changing_Assistant_Step_Pp_Display_Mode_2_DE_Display_Mode_2
    (tmp);

  /* Switch: '/Switch2' */
  if (tmp_0 > 0.0) {
    tmp = rtb_Highway_Display_Mode_3;
  } else {
    tmp = Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_3;
  }

  /* Outport: '/Display_Mode_3' */
  Rte_IWrite_Highway_Assistant_Lane_Changing_Assistant_Step_Pp_Display_Mode_3_DE_Display_Mode_3
    (tmp);

  /* Switch: '/Switch3' */
  if (tmp_0 > 0.0) {
    tmp_0 = 94.0;
  } else {
    tmp_0 = Highway_Assistant_Lane_Changi_B.Lane_Display_Mode_4;
  }

  /* Outport: '/Display_Mode_4' */
  Rte_IWrite_Highway_Assistant_Lane_Changing_Assistant_Step_Pp_Display_Mode_4_DE_Display_Mode_4
    (tmp_0);
}

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

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

Result:

The following is the Model Advisor Report:

Fig: Model Advisor Check

There are warnings that are acceptable but the notable part is that there is not a single Failed result.

Conclusion:

Developed a Model of a feature of Highway Assistant-Lane Changing Assistant as per MAAB guidelines, produced Model Advisor Report as well as generated Code using AUTOSAR Coder.