Project 2 Adaptive Cruise Control

Objective -

• To develop Adaptive Cruise Control feature as per the Requirement Document following MAB Guidelines using MATLAB Simulink.
• To generate the C code for the model developed.

Development of the Model -

1. Creation of Data Dictionary File -

• In the Modelling tab, select Link to Data Dictionary.

Fig 1 - Link to Data Dictionary Option in Modelling Tab

• The sldd file creation window will open.
• Add a New File and rename the file.
• Also, uncheck the "Enable model access to base workspace".

Fig 2 - Link to Data Dictionary Dialogue Box

• Click OK.
• From the Modelling tab, open Model Explorer.

Fig 3 - Model Explorer in Modelling Tab

• In the Model Explorer window, locate the sldd file in the External Data.
• Make entries to sldd file from the Requirement Document.

Fig 4 - Signals and Parameters List from Required Document

• For the Input Signal,Storage Class used is ImportedExtern.
• For the Output Signal, Storage Class used is Export to File.
• For the Local Signal, Storage Class used is Localizable.
• For the Clibration Signal, Storage Class used is Const.
• After making all the entries in the sldd file, Save the file.
• The sldd file is shown below in Fig 5 after making all entries.

Fig 5 - sldd File after making all entries

2. Model Settings -

• In the model settings, Solver Configuration and Code Generation setting is configured.
• In the Solver Configuration, the solver is set to Fixed Step Discrete solver.
• The Step Size is given as 0.01 as provided in the Required Document.

Fig 6 - Solver Setting

• In the Code Generation settings, the Embedded Coder file ert.tlc is selected as System Target File.

Fig 7 - Code Generation Settings

• In the Code Generation Setting, in the Interface setting check the box for Support Floating Numbers.

Fig 8 - Code Generation Interface Settings

3. Model Development -

• As provided in the Required Document, the Input Signals are
  • CameraInput_LeadVehicle
  • RadarInput_LeadVehicle
  • CameraInput_DriveVehicle
  • RadarInput_DriveVehicle
  • Time_Gap
  • Set_Speed
  • Set_Gap
  • CruiseSwitch
  • SetSwitch
• And the Output Signal is Acceleration_Mode.
• A Subsystem is created to implement the required logic.
• This Subsystem is named as Adaptive_Cruise_Control_Logic.

Fig 9 - Model for Adaptive Cruise Control

• The inputs and outputs of this subsystem is same as of Input and Outputs of the Model.
• For each Requirement a separate Subsystem is created and name of subsystem is as present in Subsystem.
• For this model, Three requirements are given so Three subsystems are created namely Lead_Vehicle, Drive_Vehicle and ACC_Algorithm.

Fig 10 - Separate Subsystem for Separate Requirement

• For Requirement 1 -
  • Lead Vehicle is a vehicle which is driving in the road ahead of our drive vehicle.
  • Two input signals for this are CameraInput_LeadVehicle & RadarInput_LeadVehicle.
  • Add both the radar & camera inputs & the corresponding output is read as Speed profile output LeadVehicle_Speed.
  • Speed data of the lead vehicle is critical in implementing the Adaptive Cruise Control algorithm.

Fig 11 - Requirement 1 Lead_Driver

• For Requirement 2 -
  • Drive Vehicle is the vehicle driven by the user & this is the vehicle which has ACC algorithm in it.
  • Like the Lead Vehicle, Drive Vehicle algorithm also has 2 input signals CameraInput_DriveVehicle, RadarInput_DriveVehicle & one signal coming as an Input to this subsystem Acceleration_Mode – three inputs into this requirement in total.
  • Two output signals come from this subsystem DriveVehicle_Speed & LeadVehicle_Detected.
  • Signal DriveVehicle_Speed is summation of three input signals mentioned above & LeadVehicle_Detected is renamed from Input Signal RadarInput_DriveVehicle by mere use of Signal Conversion block.

Fig 12 - Requirement 2 Drive_Vehicle

• For Requirement 3 -
  • Adaptive Cruise Control feature has 3 major modes of operation: OFF Mode, STANDBY Mode & ON Mode.
  • This particular requirement has to be implemented as state machine logic in Simulink.
  • The input signals to this state machine system are Time_Gap, Set_Speed, Set_Gap, CruiseSwitch, SetSwitch.
  • Also, the output signals DriveVehicle_Speed & LeadVehicle_Detected from requirement-2 is fed back as an input signal into this state machine block.
  • Additionally, output signal LeadVehicle_Speed from requirement-1 is given as an input signal to this state machine block as well.
  • Output from this subsystem is a signal Acceleration_Mode which governs the vehicular speed of the drive vehicle which automatically adjusts its speed & velocity to match the lead vehicle.

Fig 13 - Requirement 3 ACC_Logic

• The chart development conditions are given in the Requirement Document.
• ACC OFF MODE state logic -
  • This is the default state inside state machine logic.
  • Output signal Acceleration_Mode is at value 0 in this state.
  • This state is governed by input signal CruiseSwitch.
  • If CruiseSwitch is equal to 1, state ACC STANDBY mode will get activated.
  • If CruiseSwitch is equal to 0, state ACC OFF mode will get activated, from either ACC ON mode or ACC STANDBY mode.
• ACC STANDBY MODE state logic -
  • This is the second activated state inside state machine logic.
  • Output signal Acceleration_Mode is at value 1 in this state.
  • This state is governed by both input signals CruiseSwitch & SetSwitch.
  • If CruiseSwitch is equal to 1, state ACC STANDBY mode will get activated.
  • If CruiseSwitch is equal to 0, state ACC OFF mode will get activated, from either ACC ON mode or ACC STANDBY mode.
  • If SetSwitch is equal to 1, state ACC ON mode will get activated.
  • If SetSwitch is equal to 0, state ACC STANDBY mode will get activated.
• ACC ON MODE state logic -
  • This state will be activated when input signal SetSwitch is equal to 1.
  • There are 6 sub states to this state logic that are:
    • LeadVehicle_Detected_Follow (Default)
    • LeadVehicle_Not_Detected
    • LeadVehicle_Detected_Resume
    • LeadVehicle_Not_Detected_Resume
    • LeadVehicle_Speed_lessthan_Set_Speed
    • LeadVehicle_Speed_equal_Set_Speed
  • LeadVehicle_Detected_Follow state logic -
    • This is the default sub state inside ACC ON MODE state.
    • Output signal Acceleration_Mode is equal to 2.
    • Condition to transit from LeadVehicle_Detected_Follow to LeadVehicle_Not_Detected, Input signal condition LeadVehicle_Detected == 0.
    • Condition to transit from LeadVehicle_Detected_Follow to LeadVehicle_Speed_lessthan_Set_Speed, Input Signals condition (LeadVehicle_Detected == 1) && (LeadVehicle_Speed < Set_Speed) || (Time_Gap < Set_Gap).
  • LeadVehicle_Not_Detected state logic -
    • Output signal Acceleration_Mode is equal to 1.
    • Condition to transit from LeadVehicle_Not_Detected to LeadVehicle_Detected_Follow, Input signals condition [(LeadVehicle_Detected==1) && (DriveVehicle_Speed == Set_Speed) && (LeadVehicle_Speed >= Set_Speed) && (Time_Gap >= Set_Gap)].
    • Condition to transit from LeadVehicle_Not_Detected to LeadVehicle_Speed_lessthan_Set_Speed, Input signals condition [(LeadVehicle_Detected == 1) && (LeadVehicle_Speed < Set_Speed) || (Time_Gap < Set_Gap)].
  • LeadVehicle_Detected_Resume state logic -
    • Output signal Acceleration_Mode is equal to 3.
    • Condition to transit from LeadVehicle_Detected_Resume to LeadVehicle_Detected_Follow, Input signals condition [(DriveVehicle_Speed == Set_Speed) && (LeadVehicle_Speed >= Set_Speed) && (Time_Gap >= Set_Gap)]
    • Condition to transit from LeadVehicle_Detected_Resume to LeadVehicle_Not_Detected_Resume, Input signal condition LeadVehicle_Detected==0.
    • Condition to transit from LeadVehicle_Detected_Resume to LeadVehicle_Speed_equal_Set_Speed, Input Signal condition [(DriveVehicle_Speed < Set_Speed) && (LeadVehicle_Speed > DriveVehicle_Speed) && (Time_Gap >= Set_Gap)]
  • LeadVehicle_Not_Detected_Resume state logic -
    • Output signal Acceleration_Mode is equal to 1.
  • LeadVehicle_Speed_lessthan_Set_Speed state logic -
    • Output signal Acceleration_Mode is equal to 4.
    • Condition to transit from LeadVehicle_Speed_lessthan_Set_Speed to LeadVehicle_Not_Detected, Input signal condition [(LeadVehicle_Detected == 0) && (DriveVehicle_Speed == Set_Speed)]
    • Condition to transit from LeadVehicle_Speed_lessthan_Set_Speed to LeadVehicle_Speed_equal_Set_Speed, Input signals condition [((LeadVehicle_Speed*1.25>=DriveVehicle_Speed) && (LeadVehicle_Speed * 0.75<=DriveVehicle_Speed)) && (DriveVehicle_Speed < Set_Speed) && ((Time_Gap<=1.25*Set_Gap) && (Time_Gap >=0.75*Set_Gap))]
  • LeadVehicle_Speed_equal_Set_Speed state logic -
    • Output signal Acceleration_Mode is equal to 5.
    • Condition to transit from LeadVehicle_Speed_equal_Set_Speed to LeadVehicle_Not_Detected_Resume, Input signal conditions is [(LeadVehicle_Detected == 0) || (DriveVehicle_Speed <= Set_Speed)]
    • Condition to transit from LeadVehicle_Speed_equal_Set_Speed to LeadVehicle_Detected_Resume, Input signal conditions [(DriveVehicle_Speed < Set_Speed) && (LeadVehicle_Speed > DriveVehicle_Speed) || (Time_Gap >= Set_Gap)]
    • Condition to transit from LeadVehicle_Speed_equal_Set_Speed to LeadVehicle_Speed_lessthan_Set_Speed, Input signals conditions [(LeadVehicle_Speed<Set_Speed) && (LeadVehicle_Speed<DriveVehicle_Speed) || (Time_Gap == 0.75*Set_Gap)]

Fig 14 - Requirement 3 State Chart

• After creating the state logic, open the Symbols Pane and define the parameters data type used in the state chart.

Fig 15 - Symbols Pane

• Also, in the Model Explorer edit the data types for the signals used in state chart.

Fig 16 - Symbols Pane

4. Signal Tagging -

• The signals present in sldd file are need to named and tagged in the model.
• When the signal is originated for the first time, this signal need to be Resolved.
• When the resolved signal goes into different subsystem it needs to be Propagated.
• It can be done either using Property Inspector or Right click the Signal and select Signal Properties.
• To resolve the signal, select the signal.
• In the Signal Properties, give the name of the signal and check the box "Signal name must resolve to Simulink signal object".

Fig 17 - Signal Resolving

• A blue colour symbol will appear in front of Signal name after resolving as shown in Fig 18.

Fig 18 - Resolved Signal

• As this signal goes into the subsystem it is needed to propagated because one signal is resolved for only one time at the point of origination.
• To propagate the signal after resolving, right click the signal and select Properties.
• In the Signal Properties, tick the second check box "Show Propagated Signal".

Fig 19 - Signal Propagate

• This Propagated Signal show between < > symblos.

Fig 20 - Propagated Signal

• This resolving and propagation is done for all signals present in sldd file.

5. Requirement Tagging -

• The Requirement Tagging is the process of linking the model with the description present in the Requirement Document.
• This tagging is done for all the requirement subsystem present in the model.
• To Tag the subsystem, select the description in Required Document which has to linked with the model.
• Right Click the subsystem.
• Select the Link to Selection in Word in the Requirements Options.

Fig 21 - Requirement Tagging

• The link is created.
• To check the link created, again right click on subsystem and go to Requirements options.

Fig 22 - Requirement Tag

• This tagging is done for all the requirement subsystem created.

6. Model Advisor Check -

• To check the model developed is according to MAB guidelines or not.
• To run this check, go to Modelling Tab.
• Open Model Advisor.
• Select the whole system in the System Selector.

Fig 23 - Model Advisor System Selector

• Model Advisor Dialogue Box will Open.
• In this Advisor menu, uncheck all the check boxes and expand the By Task Option.

Fig 24 - Model Advisor Checks Select

• After expanding the By Task option, select only Modelling Standards for MAB.

Fig 25 - Modelling Standards for MAB

• This option contain a total of 144 checks.
• Click on Run Selected Checks.

Fig 26 - Model Advisor MAB conditions Checks

• For the model developed out of 144 checks, it passes 124 checks and the remaining 20 checks are warnings.
• The number of warnings can be reduced by clicking the checks containing yellow exclamatory mark.
• In the description of the selected check, cause of warning and its redeemption is given.
• Follow the instructions and try to reduce as much warnings as possible.
• After removing all possible warnings, again run the checks with warning sign.
• It will show the pass green mark.

Fig 27 - MAB Analysis after Removing all Possible Warnings

• After removing all possible warnings, th e number of warnings reduced to 9.
• After this Generate Report for the Checks Done in Model Advisor by clicking Generate Report Option.

Fig 28 - Model Advisor Report Generation

• Provide Name and Directory Path in Model Advisor Report Generation Dialogue Box.
• This will generate the report.

7. Code Generation -

• For the model developed C code is generated to provide it to the Electrical Control Unit (ECU).
• To generate the code, in the Apps tab select the Embedded Coder.

Fig 29 - Embedded Coder in Apps Tab

• Select Build Option to generate the C code for the developed model.

Fig 30 - Code Generation

• When the code is generated select View Code option to open the generated code file.

Fig 31 - Generated C Code

Conclusions -

• The Adaptive Cruise Control feature is developed successfully in MATLAB Simulink as per MAB guidelines.
• The C Code is generated for the Adaptive Cruise Control Model.

Google Drive Link for the Project Folder - Project_Adaptive_Cruise_Control