Challenge

Project 2-Highway Assistant-Lane Changing Assistant

RRajath M28 Dec 2022

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.

OBJECTIVES:

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.

THEORY:

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.

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

Problem Statement:

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.

Input Signals:

Name of the Signal	Data Type	Range
Highway_Input_Signal	uint8	0 - 255
Enable_Display	uint8	0 – 255
Input_Switch	uint8	0 – 255
Lane_Input_Signal	uint8	0 - 255

Local Signals:

Name of the Signal	Data Type	Range
Highway_Display_Mode_1	uint8	0 - 255
Highway_Display_Mode_2	uint8	0 – 255
Highway_Display_Mode_3	uint8	0 – 255
Highway_Display_Mode_4	uint8	0 – 255
Lane_Display_Mode_1	uint8	0 – 255
Lane_Display_Mode_2	uint8	0 – 255
Lane_Display_Mode_3	uint8	0 – 255
Lane_Display_Mode_4	uint8	0 – 255

Output Signals:

Name of the Signal	Data Type	Range
Display_Mode_1	uint8	0 - 255
Display_Mode_2	uint8	0 – 255
Display_Mode_3	uint8	0 – 255
Display_Mode_4	uint8	0 - 255

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.

Condition

Action

Highway_Input_Signal = 1

Enable_Display = off

Input_Switch = on

Highway_Display_Mode_1 = 232

Highway_Display_Mode_2 = 183

Highway_Display_Mode_3 = 41

Highway_Display_Mode_4 = 94

Highway_Input_Signal = 1

Enable_Display = on

Input_Switch = on

Highway_Display_Mode_1 = 213

Highway_Display_Mode_2 = 183

Highway_Display_Mode_3 = 9

Highway_Display_Mode_4 = 94

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.

Condition

Action

Lane_Input_Signal= 6

Enable_Display = off

Input_Switch = on

Lane_Display_Mode_1 = 132

Lane_Display_Mode_2 = 185

Lane_Display_Mode_3 = 54

Lane_Display_Mode_4 = 67

Lane_Input_Signal= 6

Enable_Display = on

Input_Switch = on

Lane_Display_Mode_1 = 127

Lane_Display_Mode_2 = 248

Lane_Display_Mode_3 = 186

Lane_Display_Mode_4 = 84

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”.

PROCEDURES ANS STEPS:

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

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_4Inside the chart, we will implement Highway_Input_Signal, Enable_Display, and Input_Switch using AND blocks. The output is given in the State.Once the Stateflow logic is written, we will resolve the port for input and output.

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. Here, from and to blocks are used to make connections easy and readable. EN_D= Enable_Display, IPS= Input_Switch, HIS= Highway_Input_Signal, HD1= Highway_Display_1,...., HD4= Highway_Display_4, LD1= Lane_Display_1,...., LD4= Lane_Display_4.

These inputs will further go to Chart, where the Stateflow logic will be written.

The outputs of chart are Lane_Display_Mode_1, Lane_Display_Mode_2, Lane_Display_Mode_3, Lane_Display_Model_4.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_ModeThe input and output signals are then resolved.

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.

The final model from the inside can be seen like this:

SIMULINK DATA DICTIONARY:

creation of the Simulink Data Dictionary File from the given calibration and signal data list. Then data dictionary should be linked to the specified simulink model

AUTOSAR DICTIONARY:

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.

before creating inports and ourports ,interfaces were created in order to map the inports and outports,Interfaces were prefix SRIf_ & their corresponding Data elements were prefix DE_.