Body Control Module (BCM)


As the electronics increasing in the vehicles, the electronic body control module (BCM) plays important role in control the vehicles body parts

  • Door Locks: Central door locking, Remote key entry
  • Wiper: Front and rear Wiper and Wash
  • Lamps: Head Lamps, Hazard lamps, Park lamps, Day time running lamp, Illumination Ring, Brake lamp
  • Mirror: Outer rear view mirror
  • Horn or Siren control
  • Ignition control
  • HVAC Control
Automotive body control

Body Control Module (BCM) also provides safety alerts (Hand brake reminders, Seat belt indicator) and diagnosis (e.g. Lamp Failures) which improves the driver's safety and reduces maintenance costs.



Body Control Module (BCM)


BCM System Architecture


Accord has designed and developed Hardware and basic software for Body Control Module.


BCM System Architecture
The following are the key features of BCM developed by Accord
  • Low sleep current achieved
  • Fully automotive grade components used in the design
  • Senses the input triggers from various sources such as internal and external lighting, parking brake sensor, 4WD sensor, wheel etc. either through digital inputs, analog inputs or through the CAN bus
  • Drives the load (external lighting, interior lighting, wipers washer, climate control, operator safety, remote start and PTO system) either directly or through relays
  • Bluetooth support for remote control operations
  • Secure key storage (SHE 1.1)
  • Secure communication
  • Scalable and Flexible basic software
  • Diagnosis
  • Program loading through UDS
  • Compliance to ISO 26262 functional safety standard

BCM Software Architecture


Number of functions in BCM are growing day by day, software shall be capable to add new functions with less or no impact on existing functions, keeping this in mind, the basic software is designed as layered AUTOSAR like architecture, where the signal interface to the application is simple and easy to integrate , also the basic software supports variant configurable inputs, outputs and diagnostic thresholds, this allows the OEM to change the BCM configuration as per the vehicle variants.


BCM Software Architecture

  • Controller abstraction layer:

    This layer contains driver components for all the hardware devices (I2C, DIO, SPI,UART, CAN,PWM,ADC and LIN) and Micro controller (System Control register Initialisation, Watchdog, Timer).
  • ECU abstraction layer:

    This layer gives device location abstraction to service layer, it contains driver components for external devices (Exernal watchdog, RF, External NVM, Switch detection, H-Bridge).
  • Service layer:

    This layer contains API components (Communication manager, Memory Manager, Watchdog manager, Timer manager) for accessing both external and internal devices.
  • Signal layer:

    This layer contains read and write data to and from devices and Application software.
  • Scheduler:

    Pre-emptive real time scheduler to execute tasks in both basic software and Application software.
  • Configuration/Calibration data:

    support the following two types of configuration:
    •  Development configuration (Configuration data)
    •  User configuration (Calibration data)

BCM Functional Safety


Functional safety is very important is for powertrain and body control systems in automotive industry. Accord applies functional safety standards (ISO 26262 , ISO 25119) for developing safety critical applications for electrical and/or electronic (E/E) systems in automotive domain. Functional safety team closely works with OEMs to prepare item definition, Hazard analysis and risk assessment, Safety goals and safety attributes (Safe state, Fault tolerance time interval and warnings) and functional safety concept.

Engineering team derives technical safety concept including system design from the functional safety concept, budget SPFM, LFM and PMHF values for each sub system in the system. Hardware and Software components implements the system design as per technical safety concept. The BCM safety goals are developed to the ISO 26262 safety standard.

The following safety analysis performed to check system meet its safety requirements:

  • System design FMEA: Analyse and check system design meets the system safety requirements.
  • Hardware FMEA: Evaluation of hardware architectural metrics (SPFM-Single point fault metric, LFM- Latent fault metric)
  • Hardware FMEDA: Evaluation of probability of safety goal violation due to random Hardware Failures (PMHF)
  • Software design FMEA: Analyse and check the efficiency of safety mechanisms

The BCM safety goals are developed to the ISO 26262 safety standard.


BCM Functional Safety

BCM Security


Connectivity is important in the modern vehicles, the BCM supports connectivity via Bluetooth and CAN. Other ECUs (Telematic unit, Diagnostic tool) in the vehicle can communicate to BCM via CAN , so secure key storage and secure communication (encryption and decryption) is developed using secure hardware extension modules. So the following security features are important in BCM:

Hardware security protection

  •   Secure Boot
  •   Secure key storage (SHE)

Software security protection

  •   Develop software to secure coding standards (CERT)
  •   Stack overflow checks
  •   Secure communication using Encryption and DecryptionData and control coupling testing

BCM Verification and Validation


Hardware

  •   Hardware design verification (Simulation, Prototype)
  •   Evaluation of hardware architectural metrics (SPFM, LFM)
  •   Evaluation of probability of safety goal violation due to random Hardware Failures (PMHF)
  •   Hardware integration testing

Software

  •   Hardware software integration testing in Hard in loop (HIL) environment
  •   Software integration testing in Processor in loop (PIL) environment
  •   Unit testing in Processor in loop (PIL) environment.
  •   Data and control coupling testing
  •   Fault injection testing
  •   Worst case timing analysis
  •   Worst cases stack analysis
  •   Tool qualification

Validation ensures the system requirements are correct and fit for the purpose and checks functional safety concepts are appropriate for the functional safety of the item. Accord team works with OEM validation team in vehicle level validation.

BCM Test Environment (HIL and ATE)

Adequate HIL environment is required to test a system in all possible normal and abnormal cases. Accord has very good experience in developing HIL and ATE equipment for both Automotive and Avionics systems. Our expert team has designed very good BCM HIL environment that helped a lot in find and fix problems at early stage of development, this has reduced hardware and software iteration cycles.

Accord Services in BCM


Accord design and developed both Hardware and Software for body control modules, our rich experience in Avionics systems design and development is an added advantage for our customers.

Accord provides services in design and develop BCM including Hardware, Software, Communication stacks, Functional safety, Certification, Security, Verification and Validation, Tool qualification and Automatic test equipment.


BCM System Architecture
Telematic Systems