Introduction to automotive ESP sensors and detailed explanation of their interface technology-EEWORLD

Collect

1. History of ESP:

Everyone is familiar with ESP, which is now widely used in the automotive industry. ESP (Electronic Stability Program) is a landmark invention of automotive electronic control.

Different companies have different names for this system. For example, Bosch and Mercedes-Benz call it ESP; Toyota calls it Vehicle Stability Control (VSC), Vehicle Stability Assist (VSA) or Electronic Stability Control (ESC); BMW calls it Dynamic Stability Control (DSC).

Although the names are different, they all add a lateral stability controller to the traditional vehicle dynamics control system, such as ABS and TCS, to control the distribution and amplitude of lateral and longitudinal forces in order to control the dynamic motion mode of the vehicle under any road conditions, thereby improving the vehicle's dynamic performance under various working conditions, such as braking, sliding, driving, etc. ESP is now widely used in new energy electric vehicles.

2. Working Principle of Automobile ESP Sensor

The working principle of the automotive ESP sensor is to provide key information to the electronic stability system by monitoring the vehicle's motion state and the driver's operation to help maintain the vehicle's stability and handling. The following are the working principles of common ESP sensors:

1. Wheel speed sensor: The wheel speed sensor usually uses magnetic induction or Hall effect principle to detect the rotation speed of the wheel. When the wheel rotates, the sensor generates an electrical signal proportional to the wheel speed, which is transmitted to the ESP control unit.

2. Steering angle sensor: The steering angle sensor usually measures the steering angle and speed of the steering wheel through a potentiometer or optical sensor. It can detect the driver's steering intention and provide information about the vehicle's steering direction and angular velocity.

3. Yaw rate sensor: The yaw rate sensor is used to measure the rotation speed of the vehicle around its vertical axis. This can be achieved through principles such as gyroscopes or accelerometers. The sensor detects the yaw motion of the vehicle and transmits the data to the ESP system.

4. Longitudinal and lateral acceleration sensors: These sensors use technologies such as piezoelectric or capacitance to measure the vehicle's acceleration in the longitudinal (front-to-back direction) and lateral (left-to-right direction). They can monitor the vehicle's acceleration, deceleration, and lateral forces.

The ESP control unit receives signals from these sensors and analyzes and processes them in combination with information from other vehicle systems (such as the brake system, engine management system, etc.). Based on the data provided by the sensors, the ESP system can determine whether the vehicle is in an unstable state and take corresponding control measures, such as adjusting the brake pressure, reducing engine output, etc., to help the vehicle maintain stability and avoid loss of control. Through real-time monitoring and rapid response, ESP sensors can provide accurate vehicle dynamic information, enabling the ESP system to intervene and adjust the vehicle's driving status in a timely manner, improving driving safety and handling performance. It should be noted that different models and ESP systems may use sensors of different types and working principles, but the overall goal is to achieve vehicle stability control.

3. ESP interface and usage protocol

The principle of the ESP (Electronic Stability Program) interface mainly involves three parts: sensor data acquisition, controller processing, and actuator control. The following is a brief description of its general principles and related protocols:

1. Sensor data acquisition: ESP systems usually use a variety of sensors to monitor the status of the vehicle, such as wheel speed sensors, steering angle sensors, lateral acceleration sensors, etc. These sensors convert the real-time information of the vehicle into electrical signals and transmit them to the controller through the interface.

2. Controller processing: The ESP controller receives sensor data and uses specific algorithms and logic to analyze the vehicle's motion state. It can detect vehicle instability, such as skidding, oversteering or understeering, and generate corresponding control instructions based on this information.

3. Actuator control: According to the instructions of the controller, the ESP system sends control signals to the actuators through the interface. The actuators may include the braking system (such as brake pressure regulator), engine management system (such as throttle control) or other related systems. These actuators will take corresponding actions to adjust the power and braking force distribution of the vehicle, thereby improving the stability of the vehicle. Regarding the protocol, the ESP interface usually adopts the CAN (Controller Area Network) protocol for vehicle network communication. The CAN protocol is a serial communication protocol widely used in the automotive field. It provides a reliable and high-speed data transmission method that allows different electronic control units to communicate with each other.

4. Detailed explanation of automotive electronics CAN bus

The protocol of the ESP interface usually adopts the standardized communication protocol CAN (Controller Area Network) bus protocol. CAN bus is a serial communication protocol widely used in automotive electronic systems. It has the characteristics of high speed, reliability, and strong anti-interference ability. Through the CAN bus, the ESP controller can interact and share data with other vehicle systems to achieve collaborative work.

The principles of the automotive CAN bus protocol can be summarized as follows:

1. Multi-master communication: The CAN bus supports multiple nodes (ECUs) to communicate simultaneously, and each node can actively send data frames.

2. Non-destructive arbitration: When multiple nodes send data at the same time, the CAN bus uses a non-destructive arbitration mechanism to determine which node has priority. The arbitration process is based on the node identification code (ID). The smaller the ID, the higher the priority.

3. Serial communication: Data is transmitted serially on the CAN bus, that is, bit by bit in a certain order.

4. Differential signal: CAN bus uses differential signal transmission, which helps to improve anti-interference ability and signal stability.

5. Data frame format: The data frame of the CAN bus contains multiple parts, such as the start bit, arbitration field, data field, check field and end bit, etc. These parts together constitute a complete communication data packet.

6. Error detection and correction: The CAN protocol has powerful error detection and correction capabilities. It can detect various types of errors, such as bit errors, stuffing errors, CRC errors, etc., and take corresponding measures to correct or report errors.

7. Identifier and data length: The arbitration field in the data frame contains an identifier to identify the meaning and priority of the data. At the same time, the length of the data field can be defined as needed.

8. Network topology: CAN bus usually adopts a bus topology, and all nodes are connected to the bus through twisted pair cables.

9. Communication speed: CAN bus supports different communication speeds to meet the needs of different automotive systems.

Through the above principles, the CAN bus achieves efficient and reliable communication between various electronic control units in the car, enabling each system to work together and improving the overall performance and safety of the car. The standardization and widespread application of the CAN bus protocol facilitates the development and integration of automotive electronic systems. For a more detailed understanding of the CAN bus protocol principles, it is necessary to further study the relevant specifications and technical documents.

Reference address：Introduction to automotive ESP sensors and detailed explanation of their interface technology

Previous article：Arteli AT32A423 new automotive-grade MCU released
Next article：The world's first 4nm automotive cockpit chip: MediaTek MT8676, which surpasses Qualcomm SA8295, is about to be installed in the car

Popular Resources
Popular amplifiers

Latest Automotive Electronics Articles

Car key in the left hand, liveness detection radar in the right hand, UWB is imperative for cars!
Automobile is an important application direction of UWB. Especially in the past one or two years, more and more models of cars on the market use UWB digital car keys, which makes us see the potential of UWB in this field. ...
After a decade of rapid development, domestic CIS has entered the market
The decline of chip giants will usher in the US automotive chip giant ON Semiconductor in 2024. Revenue in the third quarter continued to fall by 20%, and the core business of sensors has declined by double digits for three consecutive quarters. The CEO said in a conference call ...
Aegis Dagger Battery + Thor EM-i Super Hybrid, Geely New Energy has thrown out two "king bombs"
In recent years, the domestic sales of new energy vehicles have exceeded expectations. In October this year, the retail sales of narrow passenger cars reached 22.61 million units, of which new energy passenger cars accounted for 11.96 million units, with a penetration rate of 52.9%. ...
A brief discussion on functional safety - fault, error, and failure
Some concepts in functional safety are more complicated, such as fault, error, and failure. Today, we will discuss these three concepts. 01 Faults are defined in functional safety as ...
In the smart car 2.0 cycle, these core industry chains are facing major opportunities!
The core industry chain of smart cars will be a must-win in the 2020 era of smart cars. Since the beginning of this year, China's auto industry has continued to advance rapidly in the fields of electrification and intelligence. ...
The United States and Japan are developing new batteries. CATL faces challenges? How should China's new energy battery industry respond?
Murata launches high-precision 6-axis inertial sensor for automobiles
Ford patents pre-charge alarm to help save costs and respond to emergencies
New real-time microcontroller system from Texas Instruments enables smarter processing in automotive and industrial applications

MoreSelected Circuit Diagrams

Change More Related Popular Components

MorePopular Articles

MoreDaily News

Guess you like