Software Requirements Specification (SRS) Project Lane Management System

Transcription

1 Lane Management System 1 Software Requirements Specification (SRS) Project Lane Management System Authors: Adam Pruim, Curtis Notarantonio, Jacob Heisey, Qiuning Ren, Matt Chebowski Customer: Dr. S Ramesh, General Motors Instructor: Dr. Cheng, Michigan State University 1 Introduction This document is divided into seven sections. Section 1 (Introduction) identifies the purpose of this document, as well as the project scope, a list of definitions of terminology used throughout the document, and a detailed organizational structure of the document. Section 2 provides an overview of the system, and outlines the product perspective, product functions, user characteristics, constraints, assumptions and dependencies and approportioning of requirements. Section 3 provides an enumerated list of specific requirements for this system. Section 4 describes any modeling requirements necessary to the system, including use-cases and various diagrams intended to give an overview of how the system is intended to function. Section 5 focuses on the system prototype, including instructions for how to run the prototype, and an example scenario which can be applied to the prototype. Section 6 lists all references used throughout this document, and Section 7 provides a point of contact for further information regarding this document and/or project. 1.1 Purpose The purpose of this Software Requirements Specification (SRS) document is to provide a detailed description of the functionalities of the Lane Management system. This document will cover each of the system s intended features, as well as offer a preliminary glimpse of the system s User Interface (UI). The document will also cover hardware, software, and other technical dependencies. This document is intended for all individuals participating in and/or supervising the Lane Management project, explicitly those employed at General Motors who are actively involved with this project, and implicitly anyone outside of General Motors who has any type of research or developmental involvement. Readers interested in a brief overview of the system should focus on the rest of section 1 (Introduction), as well as section 2 of the document (Overall ), which provide a brief overview of each aspect of the system as a whole. These readers may also be interested in section 6 (references) which references other documents pertaining to this system, as well as a link to the team s

2 Lane Management System 2 website, where more information, as well as an interactive system prototype, can be found. 1.2 Scope The product to be produced is titled Lane Management System. The Lane Management System (LMS) is intended to be an autonomous feature that will be implemented in General Motors consumer vehicles. The application domain of the LMS is an embedded system for automotive systems. The LMS is composed of two main components: hardware installed on both the interior and exterior of the vehicle which will allow for accurate lane detection and user control of the system, as software which will allow various components of the system to communicate and respond accordingly to corresponding conditions and scenarios the user may face. A list of such scenarios can be found in in section 5.2 (Sample Scenarios) of this document. The LMS is also composed of several subsystem elements, listed below: Camera Sensing Subsystem: captures images on the sides of vehicle and sends over to the image processing unit for lane marker detection Image Processing Subsystem: processes the raw images coming from the camera and identifies the lane marker Vehicle State Estimation system: a set of sensors that would periodically determine the speed, steering angle and road curvature Path Prediction Subsystem: a software subsystem receives information from the image processing and vehicle state estimation subsystems and tries to predict the path of the vehicle in order to detect, warn and possibly correct any potential lane violations User Interface Subsystem: the driver and LMS exchange control and data information through this system Supervisory Control Subsystems: controls all other subsystems, decides when to enable and disable other subsystems and possibly provide diagnostic information The main objective of this system is to improve the safety of both the main driver, and drivers that are outside of this system (drivers that are not in the vehicle, but share the road with the primary user). Our goal is to develop a system that improves the safety of the driver, but also gives the driver complete control of the system, and the entire vehicle. The benefits we aim to provide with this system include the following: Improve driver safety Improve safety of other drivers who share the road with the primary driver Give the user the ability to have complete control over the LMS and therefore the entire vehicle. Control of the vehicle by the driver should not be interfered with as a consequence of the use of the LMS Provide both an audible and visual warning should the driver unintentionally leave their lane Provide corrective action should the driver unintentionally leave their lane. This corrective action is not to take place before a warning is issued

3 Lane Management System 3 The LMS will NOT interfere with any decision the driver may choose to make in a given scenario. 1.3 Definitions, acronyms, and abbreviations This document features some terminology and acronyms which readers may be unfamiliar with. Definitions of these terms and acronyms can be found below. Readers should refer to this section of the document should they come across any terms that are unclear. Definitions: Lane Management System Driver assistance system that can detect lanes and compute the relative position of the vehicle. Can take over control from the driver to position the vehicle within a lane. Utilizes the lane keeping system, lane departure warning system, and lane centering system Lane Keeping System Intervenes and sends commands to steer and adjust the position of the vehicle Lane Departure Warning System Makes use of lane sensing feature and issues warnings to the driver when the vehicle leaves a lane Lane Centering System Detects lane markings to compute appropriate center of lane position Acronyms: SRS Software Requirements Specification LMS Lane Management System LKS Lane Keeping System LDWS Lane Departure Warning System LCS Lane Centering Systems GM General Motors SW Software HW - Hardware 1.4 Organization Following this subsection of this document, readers will find various sections that provide a low-level overview of the Lane Management System. The structure of this document can be seen below: 1. Introduction 1.1 Purpose 1.2 Scope 1.3 Definitions, acronyms, and abbreviations 1.4 Organization 2. Overall 2.1 Product Perspective 2.2 Product Functions 2.3 User Characteristics 2.4 Constraints

4 Lane Management System Assumptions and Dependencies 2.6 Approportioning of Requirements 3. Specific Requirements 4. Modeling Requirements 5. Prototype 5.1 How to Run Prototype 5.2 Sample Scenarios 6. References 7. Point of Contact 2 Overall This section covers the function and constraints of the LMS. It provides context for the system and presents the goals of its functionality. Restrictions, on both the user and the system, are enumerated. It also explores the possible future for the LMS. 2.1 Product Perspective LMS is an autonomous feature that operates within the vehicle. It takes data from cameras within the system and applies its algorithms to those images to find the lane boundaries. It will then interact with the steering column to make adjustments and keep the vehicle in its lane. The LMS is focused on safety and will not operate if it does not have enough information to find lane boundaries. The interface is very limited and only allows the customization of a few features of the system. Visual warnings would be displayed on the dash and audio warnings will be played through the speakers. 2.2 Product Functions The function of LMS is to ensure a vehicle will hold its lane in cases where the lane boundaries can be established and the vehicle is traveling faster than twenty miles per hour. It is intended to provide convenience and safety to its users and prevent accidents that may occur when a car drifts out of its lane. LMS will not interfere with the driver's ability to operate their vehicle as they normally would. 2.3 User Characteristics Users of the system are expected to have a valid driver's license and proper faculties to operate a motorized vehicle. They should also be introduced and familiar with the audio warnings the system creates and the method involved in turning the system off. 2.4 Constraints The LMS will not make rapid steering corrections that could endanger the driver. The LMS will shut down if the system fails to find lane barriers or the center of the lane. The LMS will not operate while the car is under twenty miles per hour. The LMS is not allowed to override the driver's direct action to make steering adjustments. The LMS is an autonomous feature.

5 Lane Management System Assumptions and Dependencies The LMS would rely on the hardware functioning properly, as well as the algorithms to find the center of the lane and the lane boundaries. It is only intended to work on roadways and with a driver that is capable of operating a vehicle. 2.6 Approportioning of Requirements In the future the LMS could be integrated into a fully autonomous vehicle system and use its features to allow driverless cars to stay within road lanes. The algorithms used to find the center of the lane and other properties of the roadway could be refined to make information more accurate. Information gathered from this system could be available to the other systems in the car. 3 Specific Requirements 1. Radio Screen 1.1. Visual icon for the system being on 1.2. Shows the settings and messages 1.3. Visual warning for lane departure 2. Torque Sensor 2.1. Detects the amount of force and direction put on the wheel by the driver 2.2. Detects the amount of torque generated by the system turning the wheel 3. Three Cameras 3.1. One camera on each side of the vehicle to manage lane barriers 3.2. One camera on the front center of the vehicle to find center of curvature of the lane 4. Warnings 4.1. Audio warning for lane drift detected 4.2. Visual warning on the cluster and radio screen for lane drift detected 5. Enable/Disable Toggle Switch 5.1. Physical button on the steering wheel for the driver to enable and disable the system 6. Settings Customization 6.1. Allow the user to change the threshold allowed for the car to drift in the lane

6 Lane Management System Settings can be changed through the radio screen 6.3. Volume of warnings can be changed here 7. Controller 7.1. Communicates through the CAN bus 7.2. Indicate the status of the system 7.3. Issue commands and retrieves data from other systems 7.4. Enable and disable the system 7.5. Disables the system if there is not enough data 8. Image Processor 8.1. Receives raw image data 8.2. Processes data to see if the lanes can be indicated or not 8.3. Sets flags inside the controller 8.4. Sends decisions to controller on what it should do 9. Maintenance 9.1. System must be updated at the dealership 9.2. System diagnostic tools to indicate if physical maintenance is needed 9.3. Hardware needed for system diagnostic tools 4 Modeling Requirements Class Diagram illustrating the objects in our system and their properties: Data Dictionary:

7 Lane Management System 7 Audio Warning Inherited from Warning System class, this describes an audio alert the driver hears. Attributes volume : int The volume of the audible warning Operations This class is inherited from the Warning System class Audio Indication Inherited from Warning System class, this describes an audio indication the driver hears. Attributes volume : int The volume of the audio indication Operations This class is inherited from the Warning System class Camera A class that describes a camera on the vehicle used for lane detection. Attributes Operations Sends_info() Sends raw picture data Is a composition of the Controller class. Sends info to the image processor.

8 Lane Management System 8 Controller A class that describes the controller of the system, everything in the system sends commands through this class. Attributes Operations Sends_info() Receive_info() System_on() Sends info to another system or class. Receives info from another system or class. Turns the system on and tells all associated classes that the system is on. Controls most of the other classes including the Lane Keeping System, Customization, Warning System, Torque Sensor, Lane Centering System, Camera, Image Processor, and Enable/Disable System. Include whether any of the extensions are used (e.g., stereotype (e.g., for software product lines), tags, constraints). Customization A class that describes the customization that the driver can do to the system Attributes Degree_of_deviation : float The amount of distance threshold between the vehicle and the lanes that

9 Lane Management System 9 the system allows before taking action. Volume_of_warning : int The volume of the warning Operations Is a composition of the Controller class. Enable/Disable System A class that is used for the driver to enable or disable the system Attributes System_enable : bool Enables the system System_disable : bool Disables the system Operations System_on() Tells the controller if the system is on or off. This class is a composition of the controller class, it tells the controller if the system is enabled or disabled. Image Processor Processes images received from the camera, detects lanes and lane curvature. Attributes Lane_Indicated : bool True if a lane has been indicated. Operations Set_flags() Sets flags in the controller Receive_info() Receives raw picture data from the camera.

10 Lane Management System 10 This class is a composition of the controller class. It receives raw picture data from the camera class, and then processes that data and sets flags in the controller class. Lane Centering System A class that centers the vehicle in the lane. Attributes Curvature : bool True if the lane currently has curvature in it. Lane_Markings : bool LaneChangeWithoutIndicatio n : bool True if there are currently lane markings found. True if there is a lane change without the driver indicating with their blinker. Operations Send_info() Sends information to the controller Receive_info() Receives information from the controller This class is a composition of the controller class. Lane Keeping System A class that keeps the vehicle in the lane. Attributes Operations Send_info() Sends information to the controller Receive_info() Receives information from the controller

11 Lane Management System 11 This class is a composition of the controller class. Associated with the steering correction class. Speed Detects the current speed the vehicle is traveling at. Attributes Mph : int Mph of the vehicle Operations This class is associated with the lane keeping system Steering Angle Finds the current steering angle of the wheel. Attributes Angle : float Operations This class is associated with the steering correction class. Steering Correction Causes the vehicle to correct its steering so it stays within the lane. Attributes Degrees : float The number of degrees that the wheel is to be turned

12 Lane Management System 12 Operations This class is associated with the Lane Keeping System Class, as well as the steering angle, speed, proximity and thermal class. Torque Sensor A class that senses the amount of torque upon the wheel. Attributes Force : float The amount of force on the wheel Direction : float The direction the wheel is turning Operations Sends_info() Sends information about the torque to the controller This class is a composition of the controller class, it sends information about the torque on the steering wheel to the controller. Visual Alert Inherited from Warning System class, this describes a visual alert the driver sees. Attributes Operations This class is inherited from the Warning System class Warning System A parent class for any alert that occurs in the system

13 Lane Management System 13 Attributes Operations Make_alert() Makes the specific alert The warning system is a composition of the controller class. Visual alert, audio warning and audio indication are inherited from it. Use case Diagram show the drivers interaction with the system and the interaction between the system and itself in different scenarios: Use Case: Lane Centering System

14 Lane Management System 14 Actors: : Type: Includes: Extends: Driver The system is actively detecting and calculating the center of the lane and the car's relationship to it. The Lane Centering System uses data from both the Camera Sensing and Image Processing subsystems to calculate the appropriate center of lane position. Primary Inclement weather, Car drifts out of lane, Changing lanes, Lane Curvature Cross-Refs: 3, 8.1, 8.2 Use cases: Inclement weather, Car drifts out of lane, Changing lanes Use Case: Actors: : Type: Lane Keeping System Driver The system detects the car is drifting and after a warning is issued makes a corrective action. The Lane Keeping system intervenes and sends commands to steer and adjust the position of the vehicle accordingly as a means of accident prevention. Primary Includes: 2, 8.3, 8.4, 7 Extends: Steering correction

15 Lane Management System 15 Cross-Refs: Use cases: Autonomy, Driver Safety Car drifts out of lane, Steering Correction Use Case: Actors: : Type: Includes: Extends: Lane Departure Warning System Driver, Car This provides warnings to the driver using the car's interface to alert the driver of a lane departure. The Lane Departure Warning System makes use of the lane sensing feature and issues warnings to the driver when the vehicle leaves a lane. Primary Inclement Weather, Changing Lanes, Car drifts out of lane Cross-Refs: 4, 1, 6 Use cases: Check Surroundings Use Case: Actors: System Disabled Driver, Car

16 Lane Management System 16 : Type: Includes: Extends: This allows the driver or the car to disable the system in case of malfunction or other factors. The system is by default enabled upon vehicle start-up, and is active at speeds above 20mph. The driver can disable the system should they choose to do so via the Enable/Disable toggle button. Primary Construction Zones, Speed Threshold Cross-Refs: 5, 1.1 Use cases: Construction Zones, Speed Threshold Use Case: Actors: : Type: Includes: Extends: Car drifts out of lane Driver, Car When the car moves from the center of the lane irregularly and is flagged by the system. This use case is valid only when the system is enabled and traveling at a speed greater than 20 mph. A distinction between intentional and unintentional lane drift is made via the torque sensors located on the steering wheel. Secondary Cross-Refs: 7, 4, 2

17 Lane Management System 17 Use cases: Lane Keeping System, Lane Departure Warning System, Lane Centering System Use Case: Actors: : Type: Includes: Extends: Inclement Weather Accounts for rainfall, snow, and other weather hazards while calculating the center of the lane. In the event of inclement weather interfering with the system s capability to function properly and accurately detect the center of the lane, the system will automatically enter a disabled state as a means of preventing any inaccurate reading. Secondary Cross-Refs: 8.3, 8.4, 5, 7 Use cases: Lane Departure Warning System, Lane Centering System Use Case: Actors: : Changing Lanes The system automatically detects when the car is switching lanes normally and takes no corrective action. The LMS distinguishes between intentional and unintentional lane drift by the driver via the torque sensor on the steering wheel of the vehicle.

18 Lane Management System 18 Type: Includes: Extends: Secondary Cross-Refs: 2, 5 Use cases: Lane Centering System Use Case: Actors: : Type: Includes: Extends: Lane Curvature Exists The system detects when the road is curving and prepares to potentially take corrective action. For this particular use case, the LMS makes use of the Camera Sensing, Image Processing, and Vehicle State Estimation subsystems to calculate and predict the curvature of the road in front of the vehicle. Secondary Cross-Refs: 8, 7 Use cases: Lane Keeping System, Lane Departure Warning System, Lane Centering System Use Case: No Lane Markings

19 Lane Management System 19 Actors: : Type: Includes: Extends: Driver, Car When there are no visible lane markings to assess the center of the lane the system automatically enters a disabled state as a means of preventing inaccurate data readings that could potentially lead to an accident or put the driver in danger. Secondary Cross-Refs: 8.3, 8.4, 7, 5 Use cases: Lane Centering System Use Case: Actors: : Type: Includes: Extends: Construction Zones When the car is driving through construction the system cannot accurately predict how the lanes will flow and will automatically enter a disabled state to prevent any type of accident or inaccurate data readings that could put the driver in danger. Secondary

20 Lane Management System 20 Cross-Refs: 5, 2, 8 Use cases: System Disabled Use Case: Actors: : Type: Includes: Extends: Speed Threshold The system should only be active at a certain speed or higher. The system is by default enabled upon vehicle start-up, but is only active at speeds greater than 20 mph. Secondary Cross-Refs: 5 Use cases: System Disabled The following State diagram describes the movement of information and action throughout the system while it is active:

21 Lane Management System 21 When the driver pushes the button to turn on the whole system through Enable/Disable System, and the Enable/System will send turn on signal to the Controller. Then the Controller will turn on the camera. The Image Processor will receive images from camera and process them, then sends all informations and flags to the Controller. If the lane cannot be indicated, the Controller will send make_alert() signal to Warning System.

22 Lane Management System 22 When the driver pushes the button to turn on the whole system through Enable/Disable System, and the Enable/System will send a turn on command to the Controller. If the system is active, the controller will send make_alert() signal to Warning System. The Warning System will return a disable signal and make alert to the driver. When the driver pushes the button to turn on the whole system through Enable/Disable System, and the Enable/System will send turn on signal to the Controller. The Controller will send information from the Image Processor to Lane Centering System, and Lane Centering System is going to check lane markings exist, curvature exist and if the vehicle is changing lane without indication. Then Lane Centering System will send all of that information to the Controller. If there are no lane markings and the vehicle is changing lane without indication, the Controller will send make_alert() signal to Warning System.

23 Lane Management System 23 When the driver pushes the button to turn on the whole system through Enable/Disable System, and the Enable/System will send turn on signal to the Controller. If informations from Lane Centering System expressed the vehicle is changing lane without indication, the Controller will turn on Lane Keeping System. Lane Keeping System does the steering correction and sends informations to the Controller. When the driver pushes the button to turn on the whole system through Enable/Disable System, and the Enable/System will send turn on signal to the Controller. If the driver exerts torque on wheel, it will turn on Torque Sensor, and Torque Sensor will estimate the force and direction, if enough, Torque Sensor will sends information to the Controller, and the Controller will send make_alert() signal to Warning System, then shut down the system.

24 Lane Management System 24 5 Prototype The prototype shows the capability to enable and disable the system, the conditions by which the visual warnings are flagged, and the settings which can be configured. 5.1 How to Run Prototype The prototype is accessed through the internet. A web browser is required to view and interact with the prototype. Additionally, it requires an internet connection to import jquery, the Web Speech API and for the user to access the prototype. The jquery library is the only dependency for this prototype. It also uses the Web Speech API. It is written in HTML, CSS and jquery. The prototype can be found at the following location: Sample Scenarios The user would like to observe the system behavior while the system is active and when a driver unintentionally drifts into the left lane containing oncoming traffic. The user begins by verifying the status of the system on the screen and in the warning bar. Both will be green while the system is currently active (Figure 5.2.1) Figure If the system is not active, the screen will display System Inactive with a red warning bar. (Figure 5.2.2)

25 Lane Management System 25 Figure The system can be activated by clicking the toggle button. (Figure 5.2.3) Figure The user may click on the scenarios to observe the behaviors. In this case, the user will click Drifting into Left Lane. (Figure 5.2.4) Figure The user can observe the vehicle moving into the left lane. (Figure 5.2.5) The warning system will then be flagged and the audio and visual warning will be raised. The speaker icon appears under the toggle button and the warning bar changes color to a bright red. (Figure 5.2.6) An audio recording will also play the audio warning. (Figure 5.2.7)

26 Lane Management System 26 Figure Figure Figure 5.2.7

27 Lane Management System 27 The vehicle then makes the correction, returns to the center of the right lane and the system returns to an active monitoring state with no warnings. (Figure 5.2.8) Figure References [1] Dr. Betty H.C. Cheng and Dr. S Ramesh, GM-Lane_Management_System-v2, General Motors [2] Dr. S Ramesh, Client Question & Answer, General Motors and Michigan State University, October 2016 [3] Adam Prium, Matt Chebowski, Quining Ren, Curtis Notarantonio, Jacob Heisey, Lane 1 Website [4] [1] Lane Keeping Assist. (n.d.). Retrieved October 12, 2016, from hnology_file/active/lka.html [5] [2] Lane Departure Alert (LDA). (n.d.). Retrieved October 12, 2016, from hnology_file/active/lda.html 7 Point of Contact For further information regarding this document and project, please contact Prof. Betty H.C. Cheng at Michigan State University (chengb at cse.msu.edu). All materials in this document have been sanitized for proprietary data. The students and the instructor gratefully acknowledge the participation of our industrial collaborators.