Project 2 Adaptive Cruise Control

Aim: To develop an MBD-compliant Adaptive Cruise Control feature as per the provided requirement document using MATLAB Simulink

Objectives:

1. Developing Adaptive Cruise Control feature as per the Requirement Document using MATLAB Simulink.
2. Follow all the MBD-related processes: Requirement Tagging & Traceability, SLDD creation, Configuration Parameter changes, Model Advisor check & Code Generation.
3. In Configuration Parameters: enable “Support Floating Numbers” under Code Generation settings.
4. Use Embedded Coder to generate the code.
5. If choosing code generation, Storage class for Input signals: ImportedExtern; Storage class for Output signal: Export to File; Storage class for local signals: localizable; Storage class for calibration signals: Const.
6. Choose sample time for all signals as 0.01s

Modeling Requirements:

Requirement 1– Lead Vehicle:

• Lead Vehicle is a vehicle that is driving in the road ahead of our drive vehicle. Two input signals (Signal Name: CameraInput_LeadVehicle & RadarInput_LeadVehicle).
• Ideally, sensor fusion techniques will be deployed to process & analyze data from cameras & radar. For complexity reasons, let’s not adapt to any such algorithms.
• We can simply add both the radar & camera inputs & the corresponding output is read as Speed profile output (Signal Name: LeadVehicle_Speed).
• Speed data of the lead vehicle is critical in implementing the Adaptive Cruise Control algorithm.

Requirement 2 – Drive Vehicle:

• Drive Vehicle is the vehicle driven by the user & this is the vehicle that has an ACC algorithm in it.
• Like the Lead Vehicle, the Drive Vehicle algorithm also has 2 input signals (Signal Name: CameraInput_DriveVehicle, RadarInput_DriveVehicle) & one signal coming as an Input to this subsystem (Signal Name: Acceleration_Mode) – three inputs into this requirement in total.
• Like the above requirement, sensor fusion techniques will also be deployed here, for complexity reasons we are ignoring them.
• Two output signals come from this subsystem (Signal Name: DriveVehicle_Speed & LeadVehicle_Detected).
• Signal DriveVehicle_Speed is the summation of three input signals mentioned above & LeadVehicle_Detected is renamed from Input Signal RadarInput_DriveVehicle by mere use of Signal Conversion block.

Requirement 3 – Adaptive Cruise Control Algorithm:

• 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 (Signal Name: Time_Gap, Set_Speed, Set_Gap, CruiseSwitch, SetSwitch).
• Also, the output signals (Signal Name: DriveVehicle_Speed & LeadVehicle_Detected) from requirement-2 is fed back as an input signal into this state machine block.
• Additionally, output signal (Signal Name: 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 (Signal Name: Acceleration_Mode) which governs the vehicular speed of the drive vehicle which automatically adjusts its speed & velocity to match the lead vehicle.

Requirement 3a – 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 the 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

Requirement 3b – 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.

Requirement 3c – ACC ON MODE state logic:

This state will be activated when the input signal SetSwitch is equal to 1. There are 6 sub-states to this state logic: They 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

Requirement 3c (i) – LeadVehicle_Detected_Follow (ACC ON MODE):

• This is the default sub-state inside the 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).

Requirement 3c (ii) – LeadVehicle_Not_Detected (ACC ON MODE):

• 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)]

Requirement 3c (iii) – LeadVehicle_Detected_Resume (ACC ON MODE):

• 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)]

Requirement 3c (iv) - LeadVehicle_Not_Detected_Resume (ACC ON MODE):

• Output signal Acceleration_Mode is equal to 1.

Requirement 3c (v) - LeadVehicle_Speed_lessthan_Set_Speed (ACC ON MODE):

• 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))]

Requirement 3c (vi) - LeadVehicle_Speed_equal_Set_Speed (ACC ON MODE):

• 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

Signals and calibration data:

Signal / Calibration Name	Signal Type	Data Type	Dimension	Min	Max	Initial Value	Units
CameraInput_LeadVehicle	Input	Uint8	1	0	255	-	-
RadarInput_LeadVehicle	Input	Uint8	1	0	255	-	-
CameraInput_DriveVehicle	Input	Uint8	1	0	255	-	-
RadarInput_DriveVehicle	Input	Uint8	1	0	255	-	-
Time_Gap	Input	Uint8	1	0	255	-	-
Set_Speed	Input	Uint8	1	0	255	-	-
Set_Gap	Input	Uint8	1	0	255	-	-
CruiseSwitch	Input	Boolean	1	0	1	-	-
SetSwitch	Input	Boolean	1	0	1	-	-
Acceleration_Mode	Output	Uint8	1	0	255	-	-
LeadVehicle_Speed	Output	Uint8	1	0	255	-	-
DriveVehicle_Speed	Output	Uint8	1	0	255	-	-
LeadVehicle_Detected	Output	Uint8	1	0	255	-	-

Steps to model the Adaptive cruise control algorithm:

1) SLDD file creation

• Create a blank Simulink model and save it
• Create a new SLDD file and link it to the model by saving it in the same directory as of the model
• Go to model explorer > Open design data from model folders and subfolders > create signals and constants required
• Add signal and constant parameters as specified in the document (provided as signals and calibration data list)
  • 

  • 2) Creating Simulink model of ACC algorithm

    • We start modeling the algorithm by creating a subsystem named Adaptive_Cruise_Control_Mode with 9 input parameters and one output parameter which is the final vehicle acceleration response
      • 
      • Three more subsystems are created for the three provided requirements namely Lead_Vehicle, Drive_Vehicle, and ACCAlgorithm
      • Lead_Vehicle subsystem: The camera and radar inputs values are taken as inputs and Lead vehicle speed will be the output as specified in requirement1
      • Drive vehicle subsystem: This block follows the conditions of Requirement2 and takes 3 input values for Camera input, radar input, and acceleration mode. There will be 2 outputs of drive vehicle speed and lead vehicle detection signal
        • ACCAlgorithm subsystem: This subsystem is developed on the Requirement3 and is made using the concept of stateflow. It takes 8 inputs and gives the acceleration mode as the final output.
        • ACCAlgorithm Stateflow diagram: The Stateflow chart is developed based on the 6 sub-requirements specified in Requirement3.
        • • • Statlow symbol pane:
            • 

          3) Signal resolving and propagation

          • Name the imports and signals by method of signal resolving and propagation.
          • A signal is resolved when it appears for the first time and the signal is then propagated then onwards
          • Signal to resolve: Right Click on the signal > properties > enter a valid signal name and click on the SLDD suggestion > check the resolve signal box > OK
            • 
          • Signal propagation: Double click on the signal, add <>, and press enter.
          • Or Click on the signal > properties > Check the "Show propagated signal" option > OK
            • 
          • The resolved signal will be propagated
          • Avoid signal overlapping by using the goto and from blocks

          4) Requirement tagging

          • Require tagging is the process of linking the model with a document or a file that explains the model requirements by just clicking on the name
          • The word document with requirement details is opened.
          • Select the heading and highlight it
      • Right Click on the subsystem that explains the highlighted portion > requirements > Link to selection in word
      • • We can now see in the requirement section that the subsystem is linked to the word document.
        • If anyone clicks on the requirement tag, the word document containing its details will be opened.

        5) Configuration of Solver settings and Code generation

        • Go to model settings > Solver > select type: Fixed step ; solver: discrete (no continuous states) ;Fixed step size:0.01 > OK
          • 
        • Go to code generation > system target file:select ert.tlc >OK
          • 
          • 

        6) Model advisor check

        • Model advisor checks are done to check compliance of the model with different guidelines
        • Run the model and check for any errors
        • If the model is error-free, we can proceed with the advisor check
        • Here we are just performing the model advisor check on MAB standards
        • Go to model advisor > select the whole system >OK
        • Model advisor > select "By task"
        • Select "modeling standards for M

        7) Code generation:

        • Once the warnings are reduced to the maximum, we can generate a C code for the model created
        • Go to model explorer > open requirement 2 > set the parameters
        • Go to APPS tab > Embedded Coder > Select the model name >Gerate code /Buil
        • The code will be displayed and it's also saved in the selected directory.
        • 

        • Simulink blocks used:

          • Subsystem
          • Add block
          • Signal conversion
          • Chart
          • Inport and outports

        • Result:

          • The adaptive cruise control is modeled in Simulink as per the given requirements and MBD guidlines
          • Performed requirement tagging on the requirement subsystem blocks
          • Solver and code generators are configured
          • SLDD file is created and linked to the model also the signals are resolved and propagated
          • Model advisor report is generated and verified
          • C-code for the model is generated and attached

The Simulink model, the model word document, SLDD file , and advisor report are attached in the form of a zip file below