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What is Electronic Control Unit in Car?
Electric vehicles have undergone a plethora of iterations in recent decades, and their performance has improved significantly using innovative automotive IT solutions such as electronic control units (ECUs) and more. These units are compact devices that can be easily embedded within the electric vehicle for controlling certain functions. An ECU can also be referred to as an electronic control module, while during the late 1900s, it was also known as an engine control unit which was used for optimization of combustion mixtures and regulation of ignition. In general, basic or economic cars consist of 1 to 5 ECUs while modern cars may consist of 20 to 40 ECUs. Luxury or advanced cars may be powered by 70 to 150 ECUs which may increase up to 50 to 100 in the case of commercial or specialized vehicles, where each one of them performs specific functions for ensuring optimal vehicle operations.
Nowadays, an ECU performs various tasks such as emission control, turbocharging activity, drive-by-wire throttle, and management of different types of system inputs received and outputs or actions delivered in an electric vehicle. They process sensor data for ensuring safety in terms of the vehicle’s operations, route planning and driving, especially in the case of self-driving cars. The ECU market size was valued globally to be around US $58.31 billion in 2022 and is expected to grow to approximately US $94.58 billion by 2029, marking a CAGR of 7.2% during this forecast period. The Indian ECU market was valued at US $7.195 billion in 2019 and is projected to reach US $10 billion by 2027 at a CAGR of 8.14%. Electronic automotive parts such as motor controllers for electric vehicles, ECUs etc. provide a well-customized driving experience for every individual. Let us explore the intricacies of the making of electronic control units in this blog and their roles in the functioning of electric vehicles in general.
Source: Fortune Business Insights
Surging market size of electronic control units in automobiles during the forecast period 2020 to 2029
History of Electronic Control Unit
Let us go through a brief overview of the history of ECUs –
1. 1960s: Simple electronic control devices developed to perform specific functions such as controlling ignition timing.
2. 1970s: Surge in vehicle emission regulations leading to an increase in the development and sophistication of ECUs. Development of engine control modules (ECMs) for managing emissions and performance of the engine.
3. 1980s: This decade marked the transition of automotive system features from mechanical to electronic control, thus increasing the production of ECUs through various IT solutions for manufacturing. Major functions such as emission control, ignition time and fuel injection were now directly controlled by these units.
4. 1990s: Advancements in the functioning of ECUs were observed through complex sensor integration. Onboard diagnostics systems (OBD-II) became the standardized norm during 1996 and were mainly controlled using these units.
5. 2000s: The preliminary electronic control module developed evolved further to manage a wider range of vehicular functions and applications by increasing their capacity and power. The supplemental restraint system that features emergency collision airbags and stability control systems, both of which are controlled by ECUs, also led to an increase in their production.
6. 2010s: Advancements in software development and the surge in advanced features of software-driven vehicles led to a rise in ECU integration. Concepts of advanced driver assistance systems, V2X connectivity and in-vehicle infotainment systems proliferated in the era of autonomous vehicles alongside ECU production due to their key role in sensor fusion data processing and reliable decision-making capabilities.
Working of Electronic Control Unit
ECUs form the technological backbone of modern vehicles and ensure optimal efficiency in all their operations. They enable a safe driving environment through various convenience features as per customer requirements. The below section provides a detailed explanation of the working of ECUs –
Internal Architecture
ECUs consist of microcontroller units that execute control algorithms and require a power supply circuit that converts the 12V DC received from the vehicle battery to 3.3V to 5V as per its requirement. It consists of analog-to-digital converters (ADC) performing the task of converting analog sensor data into digital signals at a sensor supply voltage of 0V to 5V for further processing. Furthermore, they consist of digital-to-analog converters (DAC) for converting digital outputs to analog signals at regulated voltage for actuators to work with.
It also controls the input/output interface for sensor data and actuator actions. An ECU requires read only memory (ROM) to store firmware, random access memory (RAM) for temporary storage of current environmental data and vehicle statistics etc. and an electrically erasable programmable read-only memory (EEPROM) or Flash memory to store calibration data and diagnostic trouble codes. Commonly used communication logic levels include controller area network (CAN), local interconnect network (LIN), or FlexRay signals that use differential signaling with a range of voltage (CAN High – 2.5V to 3.5V; CAN Low – 2.5V to 1.5V). A typical electronic control unit completes a cycle consisting of a read-process-write procedure within 1 to 10 milliseconds as per its functional complexity. There are various simulation tools such as Vector CANoe, ETAS INCA etc. that can assist in the design and development of ECUs and other electronics manufacturing services.
Step-by-Step Operations
1. Input Acquisition: Sensor data as analog or digital (pulse width or frequency) signals are gathered from various vehicle components such as temperature, speed, throttle position etc., where analog signals are digitalized by ADC in the ECU.
2. Signal Processing: The microcontroller interprets the digitalized input such as fuel level etc., using software algorithms and calculates necessary actions, their impact and time, for example, air-fuel ratio, ignition timing, gear shift timing etc.
3. Decision Logic: As per in-built logic, ECU can make real-time decisions related to actions to be taken such as increased throttle, fuel injection and minimal ignition timing.
4. Actuator Control: The ECU in electric vehicle sends voltage or pulse width modulation (PWM) signals to actuators such as fuel injectors and idle control motors.
5. Self-Diagnostics: These units use communication protocols such as CAN bus to share data to and from other ECUs, for example, an established communication pathway between the engine ECU and the transmission ECU for speed-related data etc. Moreover, these units monitor sensor and actuator faults and store DTC in memory that can be read via diagnostic tool integration like OBD-II port or PicoScope using scan tools.
Functions of an Electronic Control Unit
ECUs play an important role in modern vehicles and serve as their digital orchestrators that optimize various operations. Let us now go through the various functionalities of the ECU –
Fuel Efficiency
ECUs can control various systems such as software handling engine systems (Engine Control Module), which helps them to make fuel utilization more efficient, as well as enhancing the overall performance and driving experience. They are also necessary for fuel optimization in autonomous driving through sensor data processing and real-time decision-making.
Safety
These units are also responsible for the working of electronic stability control, keyless entry, supplemental restraint system (Airbag Control Module), traction control system, side obstacle detection, vehicle detection system and automatic braking control system (Anti-Lock Braking Control Module), all of which play an important role in handling the occupant’s safety (Adaptive Cruise Control), stability (Electronic Stability Control) of the vehicle’s operations and avoiding bumping into the vehicle in front (throttle control), wheel lockup or skidding during traffic congestion, hard braking or slippery conditions respectively.
Various functions of electronic control units in automobiles
Powertrain Management
Similar to vehicle control unit for electric vehicles, an ECU can control the electric flow between the motor and the battery. Therefore, the powertrain control module is responsible for controlling speed, torque, pressure, battery charging, transmission, restraint control, and gear shifting (Transmission Control Unit) as well as regenerative braking of the hybrid or electric vehicle to ensure the parametric values specific to electric propulsion always remain efficient enough within safer limits.
Thermal Management
The electronic control module performs continuous monitoring of vehicle parts and their temperatures, including motor, air conditioning and distribution system, fan speed, and battery. They prevent overheating and promote efficient climate control by regulating the temperatures by adjusting power limits and involving heating, ventilation and air conditioning (HVAC) systems. They also directly manage the engine by controlling fuel injection, ignition timing, and emissions, apart from maintaining cabin comfort.
Communication
Electronic control units in automobiles maintain coordinated control between various systems and components like radio, diagnostics (error code storing, fault detection and maintenance), telematics control unit etc. while optimizing their functioning. They improve reliability, facilitate seamless integration, and interface with external systems via CAN bus or similar networks as discussed earlier, including charging infrastructure.
Battery Management
ECUs play the vital role of increasing the longevity of batteries through continuous monitoring of battery management systems. They scrutinize battery health, state of discharge, state of charge, and ensure optimal voltage, temperature, etc. of the battery monitoring system. They showcase adaptive performance as per driving conditions and user behavior.
Others
ECUs also manage the automotive’s entertainment system consisting of radio, navigation, V2X connectivity, multimedia, touchscreen interface etc. using an infotainment control module. They also assist drivers in power steering by using a steering control module that processes the information received from the steering angle sensors and sends requisite actions to the safety system. These units also manage the driver’s comfort-related features such as climate control, driver seat control, parking aid, vehicle body (body control module) and lighting, door locks, power windows, and more.
Explore the Future of ECU in Electric Vehicle with KritiKal
Electronic control units play an important role in boosting the automotive industry as they showcase key features including connectivity, driver safety enhancement, refinement of vehicle-system integration etc. These are basically microcontroller-based systems used in various industrial and automotive applications to control specific functions such as processing sensor-based data and sending signals to actuators. With advanced technologies such as artificial intelligence and machine learning embedded into the functioning of these units, the electric vehicle’s performance, fuel utilization and safety measures can be increased multifold.
They are necessary for smart cities as they contribute to low carbon emissions and cooperative traffic flow. Electronic control units in automobiles also form a crucial part of advanced driver assistance systems, especially in the case of autonomous vehicles. KritiKal can assist you in the design and development of sophisticated ECUs by using advanced simulation tools. With our team of domain experts with extensive experience in C, C#, development of programming interfaces such as JTAG, UDS over CAN and diagnostic tool integration including OBD-II etc., we can ease your ECU development process at affordable costs. Please get in touch with us at sales@kritikalsolutions.com to know more about our products and realize your automotive requirements.
Rohan Gupta currently works as a Firmware Engineer at KritiKal Solutions. He is proficiently skilled in working with diverse communication protocols, force sensors, BLE modules, MAX31342 integrated circuit etc. With his strong understanding of electronic components and circuits, he has assisted KritiKal in delivering various projects with optimal results to some major clients within efficient timeframes.