Electronic parking system EPB block diagram, chip, parking motor structure

EPB, electronic parking brake system (Electronic Parking Brake), is used to replace the traditional parking brake device based on mechanical levers and chains, providing drivers with simpler and safer parking assistance, and at the same time, it also improves driving efficiency. space around the seat.

In the core track of chassis electronic control, EPB is one of the few functions where domestic suppliers occupy a considerable market share. The EPB market is currently entering the "ceiling" of traditional product growth and entering the "new" stage of chassis wire control and integration. Growth track

EPB system block diagram and introduction

The development history of EPB electronic parking systems can be divided into three types: cable-type EPB, independent EPB, and integrated EPB. The latter two types both contain EPB controllers and are widely used; the controller of the integrated EPB system is generally It is integrated with the ESC controller, which is the current mainstream product EPBi on the market.

This block diagram is a stand-alone EPB block diagram

As shown in the picture above, obtain the EPB switch status and remind it through the indicator light;

Control the parking motor (drive, current sampling, position feedback);

Communicates with the instrument panel, electronic brake control unit, and ESC through the CAN bus;

Obtain the current driving and slope status of the vehicle through the angle sensor and acceleration sensor;

Parking motor and caliper structure

Belt-driven reduction gear. If you are interested, you can watch the disassembly video: https://www.zhihu.com/zvideo/1299055095947055104

Regarding calipers, the waiter searched for a lot of information, many of which were based on hydraulic principles. Later, I found that the introduction of Bosch's iBooster was relatively clear. You can see that the top pinion rotates, driving the vertical column gear, and the vertical gear drives the caliper. The following transverse gear & transmission mechanism

EPB chip

EPB needs to meet functional safety ASIL-D level:

Main control chip : MCU that meets functional safety, such as Infineon TC2XX series; ST's SPC56/57 series, etc.;

Braking IC: The integrated one is mainly ST's L9369, and the separated one is usually multiple half-bridge drivers;

MOSFET : Generally 40V N-MOSFET, such as ST's STD134N4F7AG, Infineon's IPG20N04S4L;

For other general devices, please refer to previous articles, such as new energy motor driver (MCU) system block diagram, chip, and functional disassembly.

Top 10 EPB suppliers

Picture excerpt from: Gaogong Intelligent Car