Project 2-Highway Assistant-Lane Changing Assistant

Highway Assistant-Lane Changing Assistant

About 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.

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.

Our Job:

To develop one specific requirement of Highway Assistant – Lane Changing Assistant algorithm. Please note that the whole Highway Assistant – Lane Changing Assistant is a very huge algorithm & only one small part of the logic is implemented here. Idea is to familiarize with concepts of Autosar Software Component Development in MATLAB Environment by following the Model Based Development guidelines. The Project must be done keeping in mind the following processes & steps.

• This 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.
• Model Advisor Report is mandatory & this will be followed by Code Generation.

Creation of sldd file:

We have been provided with following data. We will create a sldd file of it.

Input Signals:

Local Signals:

Output Signals:

Once this is done, we will begin to develop the model:

Development of Simulink model:

Path: lane_changing_assi/LCA_logic

We will now see its creation requirement wise:

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.

Path: lane_changing_assi/LCA_logic

Path: lane_changing_assi/LCA_logic/Highway_DisplayUnit

Path: lane_changing_assi/LCA_logic/Highway_DisplayUnit/HDU_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 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.

Path: lane_changing_assi/LCA_logic

Path: lane_changing_assi/LCA_logic/Lane_DisplayUnit

Path: lane_changing_assi/LCA_logic/Lane_DisplayUnit/LDU_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. 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”.

Path: lane_changing_assi/LCA_logic

Path: lane_changing_assi/LCA_logic/Display_Mode

After resolving signals at high level and propagating signals at low level and giving a update check (Ctrl + D) we have finally implemented the logic in Simulink model.

Code generation:

We need to configure the model in AUTOSAR environment (code generation profile) as shown below:

We will now proceed with AUTOSAR port mapping:

For this select C code perspective:

After this we will be able to enter in AUTOSAR dictionary.

We first add the interfaces for input and output ports just by adding prefix SRFIf to it. Also, respective Data elements will be added by adding prefix DE to the same input and output ports name.  

Once this is done, we are allowed to add input (Receiver ports: Add prefix Rp to same input port name) and (Sending ports: Add prefix Pp to same output port name) output ports.

Receiver ports (Input ports):

Sending ports (Output ports):

Runnables:

Assigning name (directories) to packages under XML option:

Now we will begin with port mapping. One instance of mapping ports is shown. It is same for every inport and outport. ( mapping it with its respective sender or receiver port along with corresponding Data elements)

We are done here with making our model in compliance with AUTOSAR (application layer) component for code generation.

Model Advisor Check:

We got zero fails here which signifies model is ready for code generation. The warning seen are mostly related to diagnostics and hence does not affect in code generation.

Code generation:

Follow the quick start menu by just clicking next tab or just hit the build icon under Autosar tab:

Generated code:

/*
 * File: lane_changing_assi.c
 *
 * Code generated for Simulink model 'lane_changing_assi'.
 *
 * Model version                  : 1.6
 * Simulink Coder version         : 9.3 (R2020a) 18-Nov-2019
 * C/C++ source code generated on : Sun Oct 17 20:54:28 2021
 *
 * 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 "lane_changing_assi.h"

/* Named constants for Chart: '<S3>/HDU_logic' */
#define IN_ED_OFF                      ((uint8)1U)
#define IN_ED_ON                       ((uint8)2U)

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

/* Model step function */
void LaneChangingAssi100ms(void)
{
  sint32 rtb_Highway_Display_Mode_3;
  sint32 rtb_Highway_Display_Mode_1;
  sint32 rtb_Lane_Display_Mode_4;
  sint32 rtb_Lane_Display_Mode_3;
  sint32 rtb_Lane_Display_Mode_2;
  sint32 rtb_Lane_Display_Mode_1;
  uint8 tmp;
  uint8 tmp_0;

  /* Chart: '<S3>/HDU_logic' incorporates:
   *  Inport: '<Root>/Enable_Display'
   *  Inport: '<Root>/Highway_Input_Signal'
   *  Inport: '<Root>/Input_Switch'
   */
  if (rtDW.is_active_c3_lane_changing_assi == 0U) {
    rtDW.is_active_c3_lane_changing_assi = 1U;
    rtDW.is_c3_lane_changing_assi = IN_ED_OFF;
    rtb_Highway_Display_Mode_1 = 232;
    rtb_Highway_Display_Mode_3 = 41;
  } else if (rtDW.is_c3_lane_changing_assi == IN_ED_OFF) {
    rtb_Highway_Display_Mode_1 = 232;
    rtb_Highway_Display_Mode_3 = 41;
    if ((Rte_IRead_LaneChangingAssi200ms_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1) &&
        (Rte_IRead_LaneChangingAssi200ms_Rp_Enable_Display_DE_Enable_Display() ==
         1) && (Rte_IRead_LaneChangingAssi200ms_Rp_Input_Switch_DE_Input_Switch()
                == 1)) {
      rtDW.is_c3_lane_changing_assi = IN_ED_ON;
      rtb_Highway_Display_Mode_1 = 213;
      rtb_Highway_Display_Mode_3 = 9;
    }
  } else {
    /* case IN_ED_ON: */
    rtb_Highway_Display_Mode_1 = 213;
    rtb_Highway_Display_Mode_3 = 9;
    if ((Rte_IRead_LaneChangingAssi200ms_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
         () == 1) &&
        (Rte_IRead_LaneChangingAssi200ms_Rp_Enable_Display_DE_Enable_Display() ==
         0) && (Rte_IRead_LaneChangingAssi200ms_Rp_Input_Switch_DE_Input_Switch()
                == 1)) {
      rtDW.is_c3_lane_changing_assi = IN_ED_OFF;
      rtb_Highway_Display_Mode_1 = 232;
      rtb_Highway_Display_Mode_3 = 41;
    }
  }

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

  /* Chart: '<S4>/LDU_logic' incorporates:
   *  Inport: '<Root>/Enable_Display'
   *  Inport: '<Root>/Input_Switch'
   *  Inport: '<Root>/Lane_Input_Signal'
   */
  if (rtDW.is_active_c1_lane_changing_assi == 0U) {
    rtDW.is_active_c1_lane_changing_assi = 1U;
    rtDW.is_c1_lane_changing_assi = IN_ED_OFF;
    rtb_Lane_Display_Mode_1 = 132;
    rtb_Lane_Display_Mode_2 = 185;
    rtb_Lane_Display_Mode_3 = 54;
    rtb_Lane_Display_Mode_4 = 67;
  } else if (rtDW.is_c1_lane_changing_assi == IN_ED_OFF) {
    rtb_Lane_Display_Mode_1 = 132;
    rtb_Lane_Display_Mode_2 = 185;
    rtb_Lane_Display_Mode_3 = 54;
    rtb_Lane_Display_Mode_4 = 67;
    if ((Rte_IRead_LaneChangingAssi200ms_Rp_Lane_Input_Signal_DE_Lane_Input_Signal
         () == 6) &&
        (Rte_IRead_LaneChangingAssi200ms_Rp_Enable_Display_DE_Enable_Display() ==
         1) && (Rte_IRead_LaneChangingAssi200ms_Rp_Input_Switch_DE_Input_Switch()
                == 1)) {
      rtDW.is_c1_lane_changing_assi = IN_ED_ON;
      rtb_Lane_Display_Mode_1 = 127;
      rtb_Lane_Display_Mode_2 = 248;
      rtb_Lane_Display_Mode_3 = 186;
      rtb_Lane_Display_Mode_4 = 84;
    }
  } else {
    /* case IN_ED_ON: */
    rtb_Lane_Display_Mode_1 = 127;
    rtb_Lane_Display_Mode_2 = 248;
    rtb_Lane_Display_Mode_3 = 186;
    rtb_Lane_Display_Mode_4 = 84;
    if ((Rte_IRead_LaneChangingAssi200ms_Rp_Lane_Input_Signal_DE_Lane_Input_Signal
         () == 6) &&
        (Rte_IRead_LaneChangingAssi200ms_Rp_Enable_Display_DE_Enable_Display() ==
         0) && (Rte_IRead_LaneChangingAssi200ms_Rp_Input_Switch_DE_Input_Switch()
                == 1)) {
      rtDW.is_c1_lane_changing_assi = IN_ED_OFF;
      rtb_Lane_Display_Mode_1 = 132;
      rtb_Lane_Display_Mode_2 = 185;
      rtb_Lane_Display_Mode_3 = 54;
      rtb_Lane_Display_Mode_4 = 67;
    }
  }

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

  /* Switch: '<S2>/Switch' incorporates:
   *  DataTypeConversion: '<S3>/Data Type Conversion'
   *  DataTypeConversion: '<S4>/Data Type Conversion'
   *  Inport: '<Root>/Highway_Input_Signal'
   *  Switch: '<S2>/Switch1'
   *  Switch: '<S2>/Switch2'
   *  Switch: '<S2>/Switch3'
   */
  tmp =
    Rte_IRead_LaneChangingAssi200ms_Rp_Highway_Input_Signal_DE_Highway_Input_Signal
    ();
  if (tmp != 0) {
    tmp_0 = (uint8)rtb_Highway_Display_Mode_1;
  } else {
    tmp_0 = (uint8)rtb_Lane_Display_Mode_1;
  }

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

  /* Outport: '<Root>/Display_Mode_1' */
  Rte_IWrite_LaneChangingAssi200ms_Pp_Display_Mode_1_DE_Display_Mode_1(tmp_0);

  /* Switch: '<S2>/Switch2' incorporates:
   *  DataTypeConversion: '<S3>/Data Type Conversion1'
   *  DataTypeConversion: '<S4>/Data Type Conversion1'
   */
  if (tmp != 0) {
    tmp_0 = (uint8)rtb_Highway_Display_Mode_3;
  } else {
    tmp_0 = (uint8)rtb_Lane_Display_Mode_3;
  }

  /* Outport: '<Root>/Display_Mode_2' */
  Rte_IWrite_LaneChangingAssi200ms_Pp_Display_Mode_2_DE_Display_Mode_2(tmp_0);

  /* Switch: '<S2>/Switch3' incorporates:
   *  DataTypeConversion: '<S3>/Data Type Conversion2'
   *  DataTypeConversion: '<S4>/Data Type Conversion2'
   */
  if (tmp != 0) {
    tmp_0 = (uint8)rtb_Lane_Display_Mode_2;
  } else {
    tmp_0 = 94U;
  }

  /* Outport: '<Root>/Display_Mode_3' */
  Rte_IWrite_LaneChangingAssi200ms_Pp_Display_Mode_3_DE_Display_Mode_3(tmp_0);

  /* Switch: '<S2>/Switch1' incorporates:
   *  DataTypeConversion: '<S3>/Data Type Conversion3'
   *  DataTypeConversion: '<S4>/Data Type Conversion3'
   */
  if (tmp != 0) {
    tmp = (uint8)rtb_Lane_Display_Mode_4;
  } else {
    tmp = 183U;
  }

  /* Outport: '<Root>/Display_Mode_4' */
  Rte_IWrite_LaneChangingAssi200ms_Pp_Display_Mode_4_DE_Display_Mode_4(tmp);
}

/* Model initialize function */
void LaneChangingAssi100msInit(void)
{
  /* (no initialization code required) */
}

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

Hence, we developed the Logic of lane changing assistance feature in Simulink environment as per the requirement. Added data into sldd file. Resolved and propagated the signals, configured model in AUTOSAR code generation profile. Assigned respective names in AUTOSAR dictionary and then did the port mapping following with the model advisor check and code generation.