Source: Automotive Maintenance Technology and Knowledge
1. Engine Electronic Control System
The Engine Electronic Control System (EECS) electronically controls the ignition, fuel injection, air-fuel ratio, and exhaust emissions of the engine, allowing it to operate under optimal conditions to improve overall vehicle performance, save energy, and reduce exhaust emissions.
Electronic Ignition System (ESA)
The electronic ignition system consists of a microprocessor, sensors, and actuators. This system calculates and determines the ignition timing based on engine parameters measured by the sensors, ensuring that the engine operates at the optimal ignition advance angle under varying speeds and air intake conditions, maximizing power output and torque while reducing fuel consumption and emissions, thus saving fuel and minimizing air pollution.
Electronic Fuel Injection (EFI)
The electronic fuel injection system gradually replaces mechanical or electromechanical fuel injection systems due to its superior performance. When the engine operates, the system calculates the optimal fuel supply based on parameters such as air flow, intake temperature, engine speed, and working temperature measured by various sensors, comparing them with pre-stored optimal operating conditions to adjust the fuel supply accordingly, ensuring the engine operates in its best state and improving overall performance while producing a certain power output.
Exhaust Gas Recirculation Control (EGR)
The exhaust gas recirculation control system is an effective measure currently used to reduce NOx emissions in exhaust gases. Its main component is the CNC EGR valve, which accurately controls the amount of exhaust gas recirculated to the engine. The ECU adjusts the recirculation rate based on the engine’s operating conditions; when the engine is under load, the EGR valve opens to mix some of the exhaust with fresh air-fuel mixture entering the cylinder for combustion, thereby achieving recirculation and optimal control of the exhaust sent to the intake system, thus suppressing the generation of harmful NOx gases and reducing their emission. However, excessive recirculation of exhaust gas may affect the ignition performance of the air-fuel mixture, impacting engine power, especially during idle, low-speed, low-load, and cold engine conditions, where recirculated exhaust gas can significantly affect engine performance.
The idle speed control system regulates the air flow by adjusting the air passage area, with the main component being the idle control valve (ISC). The ECU compares the target speed determined from the input signals of various sensors with the actual engine speed, calculates the control amount corresponding to the target speed based on the difference, and drives the actuator controlling the air amount, keeping the idle speed near the optimal state.
In addition to the above control devices, the electronic technologies utilized in the engine include: throttle timing, secondary air injection, engine boosting, fuel vapor evaporation, combustion chamber volume, compression ratio, etc., which have been applied in some vehicle models.
2. Powertrain Electronic Control System
Electronic Automatic Transmission (ECAT)
Generally, the required speed and torque at the vehicle’s drive wheels differ significantly from those provided by the engine, necessitating a transmission system to change the gear ratio between the engine and drive wheels, transmitting engine power to the drive wheels to adapt to changing external loads and road conditions. Additionally, parking and reversing also rely on the transmission system, which must coordinate the operation of the engine and transmission system to fully utilize the potential of the powertrain, achieving optimal matching—this is the fundamental task of the transmission control system.
ECAT can automatically change the position of the gear lever based on calculations and judgments of parameters such as engine load, speed, vehicle speed, brake status, and various parameters controlled by the driver, accurately controlling the gear ratio according to shift characteristics to achieve optimal control of gear shifting, ensuring the best gear and shift timing. This device features high transmission efficiency, low fuel consumption, good shift comfort, smooth driving, and long transmission lifespan. The use of electronic technology, especially microelectronics, to control the transmission system has become the main method for achieving automatic transmission functionality in current vehicles.
Electronic Four-Wheel Drive Technology (4WD)
The driving force of a vehicle comes from the tire’s grip on the ground; four-wheel drive fully utilizes this grip to achieve better driving performance. However, since the turning radii of each wheel differ during steering, the rotation speeds of the wheels also vary (inner vs. outer, front vs. rear), necessitating the use of differentials between the left and right wheels as well as the front and rear drive shafts. This brings about the issue that the driving force of the four wheels is limited by the wheel with the least grip on the ground, requiring the addition of a differential lock. Electronic four-wheel drive technology senses the conditions of all four wheels on the road through sensors, analyzes and judges this data via a microcomputer, and drives electromagnetic valves to alter the characteristics of the viscous coupler, distributing driving force between the front and rear axles as well as between left and right wheels.
Anti-lock Braking System (ABS)
This system detects the rotation speed of each wheel or axle through speed sensors installed on them, calculates wheel slip, and compares it with the ideal slip rate to decide whether to increase or decrease the brake pressure, commanding actuators to timely adjust the brake pressure to keep the wheels in an ideal braking state, allowing for braking with minimal slip. This has become a standard configuration for small passenger cars.
Electronic Brakeforce Distribution (EBD)
During braking, if the conditions of the four tires’ grip on the ground differ, the friction force between the tires and the ground will vary, leading to potential skidding, tilting, and rollover when braking (with the same braking force for all four wheels).
EBD’s function is to rapidly calculate the friction force values of the four tires due to differing grip during braking, then adjust the braking mechanism to match the braking force with the friction force (traction) according to a preset program, ensuring vehicle stability and safety. This system significantly enhances braking performance when used in conjunction with ABS.
Drive Slip Control System (ASR)
The functionality and expansion of the anti-lock braking system are embodied in the drive slip control system (ASR), which shares many components with ABS. This system utilizes speed sensors on the drive wheels to detect if they are slipping; when slipping occurs, the control element reduces speed through braking or throttle control, preventing further slipping. Essentially, it acts as a speed regulator, improving longitudinal grip between the wheels and the road during rapid speed changes during starts and turns, providing maximum driving force, enhancing safety, and maintaining directional stability of the vehicle.
Electronic Stability Program (ESP)
This is a slip prevention system; ESP can detect vehicle instability and control the braking system, engine management system, and transmission management system to compensate for vehicle sliding, preventing the vehicle from leaving the lane.
Similar products from other companies include:
Nissan: Vehicle Dynamic Control (VDC).
Toyota: Vehicle Stability Control (VSC).
Honda: Vehicle Stability Assist Control (VSA).
BMW: Dynamic Stability Control (DSC).
Electronic Parking Brake System (EPB)
This system integrates temporary braking during driving and long-term braking after parking, implemented via electronic control for parking brake functionality.
EPB operates similarly to mechanical parking brakes, tightening the rear brake shoes via a cable. Alternatively, it may use electronic mechanical calipers that apply pressure to the brake pads through a motor to achieve parking brake control.
EPB extends from basic parking functionality to automatic parking (AUTO HOLD). The application of automatic parking technology allows drivers to avoid long periods of braking when stopping and prevents unnecessary rolling when the automatic electronic parking brake is engaged, simply put, the vehicle will not roll back.
4. Steering Control System
Electric Power Steering System (EPS)
When steering, the torque sensor mounted on the steering shaft continuously measures the torque signal on the steering shaft, which is input along with the vehicle speed signal to the Electronic Control Unit (ECU). The ECU determines the magnitude and direction of the assist torque based on these input signals, and the motor’s torque is applied to the vehicle’s steering mechanism through an electromagnetic clutch and a reduction mechanism, providing steering force that adapts to the vehicle’s conditions.
Electronic Four-Wheel Steering Technology (4WS)
When a vehicle turns while driving, lateral forces cause the front wheels to understeer, while the rear wheels tend to oversteer. The latter can lead to instability in steering, which becomes more apparent at higher speeds, potentially causing skidding or rollover.
A common solution is to have the rear wheels turn 1° to 2° in the same direction as the front wheels for compensation. Electronic four-wheel steering technology senses the front wheel speed, steering wheel angle, and vehicle body deflection through sensors, processes this data via a microcomputer, and drives a servo motor to steer the rear wheels, with a response time of only milliseconds.
5. Driving Control System
Adaptive Suspension System (ASS)
The adaptive suspension system can automatically and timely adjust the damping characteristics of the suspension and the stiffness of the suspension springs based on the instantaneous load on the suspension, maintaining the predetermined height of the suspension, significantly improving vehicle stability, maneuverability, and passenger comfort.
Cruise Control System (CCS)
Cruise Control, also known as a speed control system, allows the driver to maintain a fixed pre-selected speed without operating the accelerator pedal. During long-distance driving, the cruise control system can be employed, allowing the driver to avoid frequent accelerator pedal operation; the cruise control device automatically adjusts the throttle opening based on driving resistance to maintain a constant speed.
If the vehicle begins to slow down while climbing, the microcomputer control system will automatically increase the throttle opening; when descending, it will reduce the throttle opening to adjust engine power. This control system will automatically disengage when the driver shifts to a lower gear or applies the brakes.
This system can reduce driver fatigue during long drives, providing significant convenience while also achieving better fuel economy.
Tire Pressure Monitoring System (TPMS)
This system automatically detects the tire pressure and temperature of the vehicle and provides alerts for abnormal tire conditions.
The system can be divided into two types: indirect tire pressure monitoring systems that determine abnormalities based on differences in tire rotation speeds, and direct tire pressure monitoring systems that install four pressure sensors inside the tires to monitor tire pressure and temperature in real-time during vehicle operation, providing timely alerts for high pressure, low pressure, and high temperature to prevent traffic accidents caused by tire failures, ensuring driving safety.
6. Safety Electronic Control System
This system is a common passive safety device found in vehicles worldwide. In the event of a collision, the electronic components ignite a nitrogen-producing substance located in the airbag, which inflates the airbag rapidly. The airbag’s role is to create a cushioning barrier between the driver and the steering wheel, and between front seat occupants and the dashboard, preventing injury from hard impacts. This device must be used in conjunction with seat belts; otherwise, its effectiveness is greatly reduced.
Collision Warning and Prevention System (CWAS)
This system comes in various forms; some automatically alert the driver when the distance between two vehicles becomes dangerously close during driving, and if the vehicles continue to approach, it will automatically control the brakes to stop the vehicle just before collision; others display the distance to obstacles when reversing, effectively preventing backing accidents.
7. Comfort Electronic Control System
Automatic Climate Control System
The Automatic Temperature Control (ATC) system, commonly known as the constant temperature air conditioning system, automatically controls and adjusts the interior temperature based on a set target temperature. The automatic climate control system consists of the refrigeration system, heating system, ventilation (air distribution) system, automatic control system, and air purification system.
The fully automatic temperature control system includes temperature sensors, control system ECU, and actuators. The temperature sensors include outside air temperature sensors, inside air temperature sensors, sunlight sensors (solar intensity sensors), and evaporator temperature sensors.
Automatic Seat Adjustment System (AAS)
This device is a product of combining ergonomic technology and electronic control technology, sensing the posture of the passengers and adapting the seat state to meet the comfort requirements of the passengers.
Adaptive Front Lighting System (AFS)
The adaptive front lighting system can adjust the low beam of the headlights based on the vehicle’s dynamic changes, steering characteristics, and other factors within the headlight illumination range, providing a response that significantly reduces driver fatigue during night driving on winding roads, allowing the driver to see the actual road conditions at turns and providing ample time for steering maneuvers and emergency responses, thereby enhancing safety during night driving. In Japan, some automakers have equipped their high-end models with AFS, such as Toyota’s “Lexus” which uses a variable “adaptive front lighting system.”
Night Vision System (NVS)
The night vision system is an all-weather electronic eye that extends the driver’s field of vision, allowing it to reach 3 to 5 times the distance illuminated by low beams, helping drivers see distant vehicle lights, and detecting objects on the road in rain, snow, and fog, significantly improving driving safety. The onboard night vision system operates based on infrared imaging principles, utilizing passive infrared imaging technology. The system does not emit any signals but uses a sensor to detect the heat of objects ahead, focusing the thermal energy onto a detector sensitive to various infrared wavelengths, which converts the radiation into electrical and digital signals to display images on the heads-up display (HUD) or the vehicle’s display screen. Currently, more and more automakers are developing and using onboard night vision systems, but due to cost reasons, major automobile manufacturers abroad only use this system in their top luxury models, such as the Hummer H2SUT, BMW 7 Series, Mercedes-Benz S-Class, Cadillac Escalade, etc. As technology advances and the production costs of night vision systems decrease, these systems will become widely adopted.
8. Multimedia Communication System
The multimedia communication system includes automotive navigation and positioning systems, voice systems, information systems, and communication systems.
Automotive Navigation and Positioning System (NTIS)
This system can select the best driving route within urban or highway networks and display maps on the screen, indicating the vehicle’s current location and the direction and distance to the destination. This essentially represents the intelligent development direction of automotive driving, potentially leading to the emergence of driverless cars.
This system includes two categories: voice alerts and voice control. Voice alerts trigger when abnormalities occur in the vehicle, such as fuel temperature, coolant temperature, oil pressure, charging, tail light, headlight, exhaust temperature, brake fluid level, handbrake, etc., and the computer outputs information to the speaker or alert system after logical judgment. Voice control allows the driver to command and control a specific component or device in the vehicle using their voice.
This system processes the engine’s operating conditions and other information parameters through a microprocessor, outputting useful information for the driver. The displayed information includes common parameters such as coolant temperature, oil pressure, vehicle speed, and engine RPM, as well as instantaneous fuel consumption, average fuel consumption, average speed, mileage, outside temperature, etc., which can be accessed by the driver as needed.
Communication System (CS)
This area is primarily represented by automotive telephony, which is widely adopted in developed countries and regions such as the United States, Japan, and Europe, and is continuously improving. Currently, it enables communication between vehicles and roads, between vehicles and other vehicles, and between vehicles and aircraft, and can connect to international telephone networks via satellites for communication, information exchange, and image transmission during travel. With the advent of wireless telephone networks, broadband digital signals, the internet, and other emerging wireless communication technologies, people can access information and services anytime, anywhere.
Vehicle Networking System (T-BOX)
The vehicle networking system consists of four components: the main unit, vehicle-mounted T-BOX, mobile APP, and backend system. The main unit is primarily used for audio-visual entertainment and vehicle information display; the vehicle-mounted T-BOX facilitates communication with the backend system/mobile APP to display and control vehicle information.
When users send control commands via the mobile APP, the TSP backend issues monitoring request commands to the vehicle-mounted T-BOX. Once the vehicle receives the control commands, it sends control messages via the CAN bus to implement vehicle control, ultimately providing feedback on the operation results to the user’s mobile APP. This functionality allows users to remotely start the vehicle, turn on the air conditioning, adjust the seats to suitable positions, etc.
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