Embedded Systems in Automobile
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The document discusses embedded systems in automobiles. It defines embedded systems and describes their characteristics. It then discusses several key automotive systems that use embedded technology like airbags, anti-lock braking systems (ABS), and event data recorders (EDRs). Airbags use sensors to detect crashes and actuators to deploy the airbags at varying levels depending on crash severity. ABS uses wheel speed sensors to detect lockup and controls braking pressure to prevent skidding. EDRs permanently record crash data to help with accident reconstruction. Embedded systems are critical components in modern automotive safety and electronic features.
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Embedded Systems in Automobile
- 1. A Technical Seminar on Embedded System in Automobile By ABHISHEK SUTRAVE (1RN05EC004) RNS INSTITUTE OF TECHNOLOGY
- 2. Embedded System- Definition? An embedded system is a combination of hardware and software which creates a dedicated computer system that performs specific, pre- defined tasks and which is encapsulated within the device it controls (if it is part of a larger device).
- 3. Industry Development Process Requirement System Specification Delivery System System Specification Test System System Design Integration Module Module Design Test Implementation
- 4. Embedded Development Tool Flow Overview Standard Embedded SW Standard FPGA HW Development Flow Development Flow C Code VHDL/Verilog Compiler/Linker Synthesizer (Simulator) Simulator Object Code Place & Route ? ? CPU code in CPU code in off-chip on-chip memory memory Download to FPGA Download to Board & FPGA Debugger
- 5. Embedded system components Software FPGA/ Memory ASIC A/D D/A Sensors CPU Actuators conversion conversion User Aux system interface Diagnostic (power port cooling, etc Electromechanical Backup and safety External environment
- 6. WHY ? EMBEDDED IN AUTOMOBILE
- 7. Characteristics of embedded systems • Sophisticated functionality. Often have to run sophisticated algorithms or multiple algorithms. Often provide sophisticated user interfaces. • Real-time operation. Must finish operations by deadlines. Hard real time: missing deadline causes failure. Soft real time: missing deadline results in degraded performance. Many systems are multi-rate: must handle operations at widely varying rates. • Low manufacturing cost. • Low power. • Designed to tight deadlines by small teams.
- 8. APPLICATIONS
- 9. Automotive Systems: Technology in today’s vehicle • Air Bags • Traction Control • The Black Box • Automatic Parking • Anti-lock Brake • In-vehicle System(ABS) entertainment • Adaptive Cruise • Heads-up display Control • Night Vision • Drive by wire • Satellite Radio Eg:XM • Back-up collision sensor • Telematics Eg:OnStar • Rain-sensing Wipers • Navigation Systems • Emission Control • Tire Pressure Monitor • Climate Control
- 10. Automotive Systems: Technology in today’s vehicle Temperature control Air bags EGR control Active suspension Electronic fuel injection Electronic ignition Electric power steering (PAS) Electronic transmission Cruise control Anti-lock brakes
- 11. Air Bags
- 12. Principle of function • It is from the Newton’s 2nd law of motion • It basically restrains the continuous motion of the passenger, by giving a soft surface to land on. • AIR BAGS are among the most important safety improvements added to cars and light trucks in recent years, providing extra protection for front-seat occupants in head-on crashes. • And of late, every passengers protection
- 13. Air Bag- Working Before Impact After Impact
- 14. Airbag System: Possible Sensors (Including Crash Severity and Occupant Detection) SAT SAT passenger detection SAT passen. WS BS BS BS SAT ECU ROS BS ACC BS driver detection WS driver SAT SAT SAT SAT = satellite with serial communication interface ECU = central airbag control unit (including accelerometers) ROS = roll over sensing unit WS = weight sensor BS = buckle switch
- 15. Airbag System: Possible Actuators (Including Crash Severity and Occupant Detection) Headbag TB Headbag TB Kneebag Airbag 2stage PBP PBP PBP Emergency Equipment ECU Interactionbag PBP Kneebag Airbag 2stage PBP Headbag TB Headbag TB TB = Thorax bag PBP = pyrotechnical buckle pretensioner with load limiter ECU = central airbag control unit
- 16. Automotive Seat Occupancy Detection DSP-based Emb system (Processes Seat w/ Fiber Information) Sensing Technology -Airbag Deployment Decisions (fire airbag? which airbags? how much to inflate?, etc.)
- 17. Automobile Accident Reconstruction or the Event Data Recorder-EDR or the The “Black Box”
- 18. Event Data Recorder-EDR • The Event Data Recorder (EDR) in an automobile is based upon the sensors and microprocessor computer system that are used to activate the airbag in the vehicle during a crash. • The SDM, which is controlled by a microprocessor, has multiple functions: • (1) it determines if a severe enough impact has occurred to warrant deployment of the air bag; • (2) it monitors the air bag's components; • (3) it permanently records information.
- 19. Event data Recorder-EDR Simplified Block Diagram Engine Speed Vehicle Speed Brake ON/OFF Throttle Pos Sensor Sensor Sensor Sensor Pre-impact data Serial data bus SDM Accelerometer Warning Indicator Low-pass Filter Airbags Power Ignition Switch Microcomputer Including EDR RAM 32k ROM 640 EEPROM Driver Seat Belt Manual Pass. Sensor Airbag Cutoff Sw. And Indicator
- 20. Black Box - Exterior
- 21. Black Box - Interior
- 22. Conclusion • The EDR is not a replacement for the accident reconstructionist. • The EDR can be a source of additional data to confirm the conclusions of the accident reconstructionist. • The EDR may serve as an effective tool to impeach conclusions reached by accident reconstructionists who fail to consider the data generated by the EDR. • A lot of trial lawyers are going to be very busy litigating all of the issues the “black box” will generate during the coming years.
- 23. Anti-lock Braking system(ABS)
- 24. Why ABS ? Up until the seventies, hitting the brakes too hard could lead to an accident. The reason: When the coefficient of slip between tires and road surface is too low, hitting the brakes can cause wheel lock-up. The vehicle is no longer steerable and goes into a skid. • In particular, this danger is present on wet or slippery road surfaces with different levels of grip between tires and road
- 25. On preventing wheel lock-up Reduce the total braking distance as far as possible Increase vehicle stability Maintain steerability even in case of all-out braking
- 26. Its Principle of functioning Wheel-speed sensors detect whether a wheel is showing a tendency to lock-up In case of a lock-up tendency, the electronic control unit reduces the braking pressure individually at the wheel concerned High-speed correction of the braking pressure up to shortly before the lock-up threshold The brake-fluid return together with the closed-loop brake circuits makes this a safe, reliable, and cost-effective system
- 27. The Components Electronic Control Unit Wheel-speed sensors Hydraulic modulator
- 28. A BASIC ANTI-LOCK BRAKE SYSTEM sensor sensor brake brake hydraulic ABS pump brake brake sensor sensor
- 29. Advantage • A gain for driving safety The vehicle remains steerable, even in case of panic braking Shorter stopping distances on practically all road surfaces • Many accidents are avoided
- 30. The Difference With ABS Without ABS The vehicle The vehicle is remains no longer steerable even steerable during panic when the braking driver hits the brake
- 33. Dynamic Traction & Stability Control
- 34. Introduction • The traction control system is required to prevent driver error from overloading any of the four wheels and causing slip, through either throttle or brake application • Drastically improve vehicle performance and safety by maintaining optimal wheel traction in all road conditions
- 35. Its Principle • The basic principle is always the adaptation of the wheel torque to the coefficient of friction between the wheel and the road surface. • To this end, the systems make use of different intervention methods In the wheel brakes In the drivetrain control
- 36. The Principle of Functioning of TCS with brakes Without TCS: The powered wheel spins – the wheel does not accelerate. Snow or ice/ Asphalt With TCS: Intervention in the brake Improved traction, the vehicle accelerates
- 37. The Principle of functioning of TCS with Drive Train Control External Slip Angle Sensors Radius X/Y/Z Acceleration Driver Physics Model + - Engine Wheels Pedal (Saturator) RPM μs/μk Throttle Pos. Wheel Slip ECU Detector
- 39. On Road works & Future Developments
- 40. Intelligent Cruise Control
- 41. Intelligent Cruise Control • Cooperative Adaptive Cruise Control with Collision Warning (CACC + CW) • CACC:Cruise at given speed when the road is clear (cruise control) otherwise follow the car in front, using radar (adaptive) and/or communications (cooperative). • CW: Warn the driver when an object is being approached too fast, or is too close. x2 x1 r Vehicle 2 Vehicle 1
- 42. Why this is hard… Around curve Rapid deceleration Elevation changes Dense traffic Cut-ins
- 43. How it works • Uses forward-looking radar, installed behind the grill of a vehicle, to detect the speed and distance of the vehicle ahead of it. • Can automatically adjust speed in order to maintain a proper distance between vehicles in the same lane
- 51. Drive by wire
- 52. Drive by wire Drive-by-Wire replaces mechanical connections – push rods, rack & pinion, steering columns, overhead cams, cables – by mechatronic connections – sensors, actuators, embedded microprocessors, control software
- 54. A Future Car with drive by wire technology
- 55. AUTOMATIC CAR PARKING
- 57. Toyota’s Autonomous Vehicle Technology Roadmap
- 58. Conclusion-It’s a connected drive