Presented by

Ankit Kaul

1PE10EC011

Under the Guidance of Prof. Sireesha B.

Architecture & Data Acquisition By Embedded Systems In Automobiles

• Introduction

• Architectural characteristics of Digital Services by Embedded Systems

• Digital Service Architecture

• Remote Diagnostics

• Embedded Sensors

• Data Handling in Formula 1 racing

• Summary

Outline

• An embedded system is typically a micro-computer system with one or few dedicated functions.

• Advanced usage of embedded system and electronics within the vehicle can aid in monitoring and diagnostic capabilities without sacrificing safety/security features.

Introduction

Fig.1: embedded devices in a vehicle

• “Every embedded system has an architecture, whether it is or is not documented, because every embedded system is composed of interacting elements (whether hardware or software).”

• The architecture of an embedded system is an abstraction of the embedded device, meaning that it is a generalization of the system that typically doesn’t show detailed implementation.

Architectural Characteristics of Digital Services

• Defining and capturing the design of a system

• Cost limitations

• Determining a system’s integrity, such as reliability and safety

• Working within the confines of available elemental functionality (i.e., processing power, memory, battery life, etc.)

• Marketing possibilities

In short, an embedded systems architecture can be used to resolve these challenges.

Importance of Embedded System Architecture

• Modular architecture exhibits one-to-one mapping between functional elements and physical modules.

• System composed of separate components shown in figure that can be connected together.

• The beauty of modulararchitecture is you can replace or add any one component (module) without affecting the rest of the system.

Modular Architecture

Fig2: Stages of Modular architecture

Layered Architecture

• Deals with hardware and operating systems, layer generally consists of embedded devices.

• Based on the collection of localization data, speed, direction of travel and time information from mobile phones in vehicles that are being driven.

• Provides application functionality that directly serves users during storage, manipulation, creation and consumption of contents such as texts, images, sounds, video etc.

• Manages logical transmission and physical transportation (cables).

• It is a hybrid between a modular architecture and a layered architecture.

Layered Modular Architecture Continuum

Re-programmability

•Allows a digital device to perform a wide array of functions such as

•calculating distances, word processing, video editing , web browsing.

Homogenization of data

•Any digital content can be stored, transmitted, processed and displayed using the same digital devices and networks.

•For example, an iPhone is not only a phone, but also a camera, a music player, a video player

Self-reference

•Means that digital innovation requires the use of digital technology, e.g., computers.

• One such innovation of the LMAC was introduction of remote diagnostics services (RDS) for the vehicles.

• Remote diagnostics of vehicles implies several functionalities:▫ Multi-Sensor integrated monitoring and control Systems. ▫ Communication and integration of geographically

dispersed machines.▫ Data abstraction – only the relevant data is to be

transmitted through the network. ▫ Knowledge acquisition and learning. ▫ Tele-Maintenance and diagnostics to facilitate the

technical personnel to perform diagnostics on machines that are geographically distributed.

Remote Diagnostics

Fig.3: Remote Diagnostics for a vehicle

Embedded Sensors

Internal Sensors• Located inside an EDR when data is not available to be read

directly from other sources

• Longitudinal, lateral accelerometers; and a GPS receiver.

Analog Input from Sensors

• refers to the electrical output of analog (i.e., continuous, 1 to 5 Volts Direct Current (VDC)) sensors

• An example of an analog sensor is the throttle position sensor.

Discrete Digital Inputs

• inputs refer to connections throughout the vehicle to on/off devices. Brake lights, turn signals, horn, running lights, and headlights are examples of this type of signal.

Vehicle Network

• Two in-vehicle data networks commonly found in large trucks: 1) a low-speed network & 2) a high-speed network. When both networks are present, the low-speed network conveys general vehicle operating data, and the high-speed network carries engine control data.

• Obtaining vehicle data via the vehicle networks is cost efficient.

Data Download• Process of transferring data stored in an EDR to another device,

• Using a data download connection, an EDR receives commands from a device (e.g., a laptop), and transmits data to it.

Fig.4: Different sensors in a car

Electronic Control Unit

• Electronic control units (ECUs) are the specialized programmable hardware platforms which automotive software runs on.

Desired Output

Fig.5: ECU in a vehicle

Controller Area Network (CAN)

• The fig.6 shows that with CAN the wiring is also reduced for inter vehicular communication.

Fig.6

CAN Working• CAN uses a message oriented transmission

protocol.• There are no defined addresses, just

defined messages.• Messages are distinguished by message

identifiers. The identifier is unique to the network and defines the content & priority of the message.

Fig.7: CAN bus transmitting data

Vehicular Advanced Communication Tool (VACT)

“The VACT collects signals from the ECUs, processes the signals and transmits the

signals to a service station with the help of wireless transmission.”

VACT is basically processing all the sensor data and yielding diagnostics information

that can be helpful to predict any anomaly that occurs in a vehicle part to reduce the

risk of a breakdown.

VACT is concerned with all the sensor data within one bus. The VACT is re-

programmable. We can upload new software to it. We can even do it wirelessly to VACT and run the new software instead

of what it is running now. This new software can then include new functions.

Every VACT system is affected by the limitations of the sensors. If any sensor

does not function properly, the application functionalities within the VACT will

eventually struggle to provide accurate information.

VACT has a ‘device layer’ that consists of different hardware units. Its ‘network layer’deals with the transmission of signals from

the sensors to the remote station. It is operated by an ‘application program’

called COSMO and it delivers contents in the form of processed signals.

• Methodology is based on creating a compact representation of the data observed for a subsystem or component in a vehicle.

• This representation can be sent to a server in back-office and compared to similar representations from other vehicles.

• The back-office server can collect representations from a single vehicle or from a fleet of vehicles to define a norm for the vehicle condition.

• Although it is used at the back office computers, a part of the COSMO algorithm must be used with each VACT inside the buses. Without that part of COSMO, VACT cannot perform on-board diagnostics.

Consensus Self Organized Modelling (COSMO)

COSMO Working

• Consider a fleet of city buses, buses that drive around in a city. Buses are driving under similar weather and load conditions (number of passengers, hills, etc.).

Equipment is able to discover, analyze, capture “interesting” patterns and associations.

When buses report to a central server, signals are compared between vehicles, against known fault signatures and to service histories.

Deviations are detected and flagged for repair / service.

This was for the back office diagnosis. Now for the on-board diagnostic we see

• F1 cars are marvels of high technology. F1 cars (and their drivers) are some of the most heavily instrumented objects in the world.

• This information lets the team constantly update its strategy for the current race and improve the car’s design for future races.

• A typical race will generate in excess of 1 Gigabyte of data.

Data Handling In Formula 1 Car

Summary

Architectural characteristics co-exist at the device and network layers

Embedded devices such as VACT not totally follow the characteristics of the modular architecture.

At the transmission layer,wired network, close to the modular, GPRS that follows layered modular characteristics as it has re-programmability.

Architecture of the digital

services spans along the

layered modular architecture continuum

The COSMO algorithm is used after receiving all the data from the VACTs. The analysis can be done without having any link with any VACT. That makes COSMO de-coupled from the VACTs

But a part of the COSMO algorithm is continuously used with each VACT which is embedded in every bus.

The application program of the

digital services is simultaneously de-coupled and partly coupled with the

embedded devices

The embedded device (VACT) in RDS has its own four layers: the device layer, network layer, application layer and the content layers.

This implies that it has its own operations like application program layer performs specific on-board diagnostics, & network layer transmits the diagnosed signals to the back-office for further analysis.

There are layers within layer of

the digital service