Challenge

Project 2 Adaptive Cruise Control

SSatya Prakash Yadav14 Jul 2022

Aim:

To develop the Adaptive Cruise Control feature as per the Requirement Document using MATLAB Simulink.

Objective:

Developing Adaptive Cruise Control feature as per the Requirement Document using MATLAB Simulink.
Follow all the MBD related processes: Requirement Tagging & Traceability, SLDD creation, Configuration Parameter changes, Model Advisor check & Code Generation.
In Configuration Parameters: enable “Support Floating Numbers” under Code Generation settings.
Use Embedded Coder to generate the code.
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.
Choose sample time for all signals as 0.01s

Adaptive cruise control:

The main reason behind cruise control technology is to make driver relax behind the wheel. Because of this, their driving experience becomes safer, thrilling and also saves the fuel consumption. By monitoring other vehicles and objects on the road, adaptive cruise control enables a safe and comfortable driving experience. It helps the driver keep a steady vehicle speed at a given moment. The driver can set their preference regarding certain factors, such as the distance to the car in front, driving mode. Together with information about speed limits, road curvature, accidents data and more, these choices influence the automatically selected speed. As less expensive sensors reached the market, adaptive cruise control is steadily becoming a standard feature in new vehicles today.

In slow-moving traffic, it automatically stops or starts vehicle movement under driver supervision. The car will brake and accelerate on its own, while maintaining a safe distance from the vehicle in front. Intelligent cruise control can automatically adjust the set speed to the newly detected speed limit when the driver is passing a speed limit sign. This is done by fusing camera observation and map data to provide reliable speed restriction information.

Radar-based systems work by placing radar-based sensors on or around plastic fascia’s to detect your vehicle's surroundings. Each radar sensor works together to create a comprehensive picture of the vehicle's proximity to other cars or potentially hazardous objects. This type of sensor can look different depending on the design and model of the car.

ACC that uses sensory data to predict the actions of neighbouring vehicles. This means that your car might slow down to brake for another vehicle suddenly switching lanes and, in doing so, promotes passenger safety.

For this project,there are several steps taken which are as follows:-

Developement of the Desired model
Configuration Parameter Setting
Linking of the Simulink Data Dictionary
Requirement Tagging
Signal resolving and Signal Propogation
Model Advisor Report Generation
C-code generation

PROCEDURE:

1. Development of Simulink model as per requirements-

SIMULINK MODEL:

Subsystem-

Requirement 1– Lead Vehicle:

Lead Vehicle is a vehicle which 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 camera & 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.

-Here two input signal as CameraInput_LeadVehicle and RadarInput_LeadVehicle is added using add block and output is as LeadVehicle_Speed.

Requirement 2 – Drive Vehicle:

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 (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 summation of three input signals mentioned above & LeadVehicle_Detected is renamed from Input Signal RadarInput_DriveVehicle by mere use of Signal Conversion block.

-Here Three input signal (ameraInput_DriveVehicle, RadarInput_DriveVehicle,Acceleration_Mode)is applied to sum block and output signal is denoted as DriveVehicle_Speed.

-Acceleration_Mode ,this is feedback signal.

- LeadVehicle_Detected,this is also output signal which is only renamed signal of RadarInput_DriveVehicle.

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 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 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 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<set_speed) &&="" (leadvehicle_speed<drivevehicle_speed)="" ||="" (time_gap="=" 0.75*set_gap)]<="" em=""></set_speed)>

State Logic Condition-

Statlow symbol pane-

2) Configuration Parameter settings:-

Solver Type is changed from variable step to Fixed step and Solver type is selected as Discrete ( No continuous state) and also sample time is declared as 0.01 sec as per the project requirement.

Also under the Code generation option selecting embedded real time as system target file (ert.tlc) under target selection option.

In chart setting ,its action language will be changed as below-

3)Linking of the Simulink Data Dictionary-

(a) -Link the SLDD file to model .

(b)-To creat the new file ,select New Tab.After selecting new ,a new window will pop-up which asked to save the file .Edit file name and save it to same folder in which Model is.

(c)-After saving file ,click on Model Explorer-

(d)-After doing Above step use below step -

(e)-click in add,if you want to add signal ,click on simulink signal(as denoted 2) and if constant then click simulink parameter(as denoted 1).

(f)-Now you can edit parameter as needed.Click on signal or constant in the dictionary object and after that on the right side as marked arrow.In which you can edit the parameter as needed.

4) Requirement Tagging:-

A MS Word file is created which contain all the requirements and necessary information to develop the model appropiately. This Word file is tagged for both the subsystem requirement1 and Requirement2 respectively.

Highlite the title as below-

now go as below-Clich right click on subsystem then>Requirements>LinkTo Selection in Word.

Same is repeated with Requirement_2 and Requirement_3.

5) Signal Resolving and Signal Tagging:-

All the input signal are resolved at the root level (which is comes at firt time)of the model and propogated (where the resolved signal is used again)accordingly as shown below:-

Right click on signal>Properties>then tick as right below image.

Output signal of Requirement1 is resolved at the root level and now propogated as -

6) Model Advisor Report Generation:-

Before Advisor report generation,RUN the Model and ensure that the model should run withour error then go for below process-

To generate the report we have to go over the Modelling tab and then there at Extreme left corner there is a option of Model Advisor and selecting Model Advisor in it.

It will ask to select the system for which the report generation is to be taken:-

Then under the By task option unselecting all the previously selcted option and then selecting the Modelling Standard for MAB there and in the right box there is option to Run sleected check and clicking over there will run the selected checks