Description and Operation

Description

Regenerative Brake System

During deceleration or braking of an electric vehicle or hybrid electric vehicle, the drive motor operates as an AC generator and charges the battery, converting the kinetic energy of the vehicle generated during braking into electrical energy. The amount of regenerative braking depends on vehicle speed, battery charge, etc. Significant improvement in fuel economy is achieved when driving in the city with repeated acceleration and braking.

Regenerative Brake Control (RBC) System

The braking force is distributed by controlling the hydraulic brake. The total braking force required by the driver is achieved by a combination of hydraulic and regenerative brakes. If the regenerative brake fails, the total braking force required by the driver is provided by the hydraulic brake system.

The AHB system consists of the Power Supply Unit (PSU) and the Integrated Brake Actuation Unit (IBAU). First, the PSU generates the hydraulic pressure required for braking. Similar to the brake booster effect in a vehicle equipped with a vacuum booster, when the driver depresses the brake pedal, the hydraulic pressure stored in the accumulator is supplied to provide pressure throughout the brake line. Second, the IBAU supplies the pressure generated by the PSU to the caliper at each wheel. In addition, it is connected to the brake pedal to determine the braking force required by the driver and generate brake pedal feel. The IBAU performs ABS, TCS, and ESC functions, as in conventional vehicles.

AHB System Operating Principles

1. Initial Status

A high pressure (180 bar) is maintained between the PSU and the IBAU at all times. Therefore, before removing the PSU or IBAU, the pressure between them must be relieved for safety by performing the "High Pressure Release Mode" of the GDS connected to the SOUL EV.

2. Brake Operation

Apply mode: When the driver depresses the brake pedal, the IN valve opens, supplying the high pressure generated by the PSU to the IBAU caliper to activate the brakes.

The braking force level is determined by the pedal simulator through measurement of the brake pedal travel sensor signal. Release mode: When the driver releases the brake pedal, the release valve opens and the IN valve closes, returning the high-pressure brake fluid back to the PSU. At the same time, the CUT valve turns on to prevent brake fluid from flowing back into the IBAU.

2. Brake Malfunction

If either the PSU or the IBAU malfunctions, both the IN and OUT valves close and the CUT valve turns off. In this case, braking force can only be obtained by manually depressing the brake pedal.

Integrated Brake Actuation Unit (IBAU) (1)

Integrated Brake Actuation Unit (IBAU) (2)

Integrated Brake Actuation Unit (IBAU) (3)

Integrated Brake Actuation Unit (IBAU) (4)

IBAU Connector Input/Output

		Description			Description
1.	R	E/R Junction Box (Fuse - IBAU 1)	24.	-	-
2.	R	Power Supply Motor (+)	25.	-	-
3.	-	-	26.	-	-
4.	B	PSU Motor (Shield Ground 2)	27.	G	Rear Left Wheel Sensor (SIG)
5.	G	Intelligent Junction Box (Fuse - IBAU)	28.	B	Front Left Wheel Sensor (SIG)
6.	R	Brake Pedal Sensor (PDT Input (Power))	29.	L	Intelligent Junction Box (IPS Control Module)
7.	P	Brake Pedal Sensor (PDT Input (Power))	30.	D	E/R Junction Box (Fuse - IBAU 2)
8.	GO	Stop Lamp Electronic Module (HAC Signal)	31.	B	Brake Pedal Sensor (PDT (Ground))
9.	-	-	32.	-	-
10.	g/g	Brake Pedal Sensor (PDT (Ground))	33.	or	Rear Left Wheel Sensor (VCC)
11.	B	PSU Motor (Shield Ground 1)	34.	D	Rear Right Wheel Sensor (VCC)
12.	-	-	35.	-	-
13.	W	Power Supply Motor (-)	36.	G	Stop Lamp Electronic Module (Stop Lamp)
14.	B	Ground (GE06)	37.	L	Stop Lamp Electronic Module (Stop Lamp)
15.	-	-	38.	G	SRS Control Module (Local CAN (High))
16.	O/B	Emergency Stop Switch (ESC OFF Switch)	39.	Br	SRS Control Module (Local CAN (Low))
17.	P	Front Left Wheel Sensor (VCC)	40.	D	Smart Key Control Module (Wheel Sensor Signal)
18.	Br	Front Right Wheel Sensor (VCC)	41.	-	-
19.	W	C-CAN (High)	42.	P	Front Right Wheel Sensor (SIG)
20.	Br	C-CAN (Low)	43.	B	Rear Right Wheel Sensor (SIG)
21.	-	-	44.	L	Stop Lamp Switch (B)
22.	W	Brake Pedal Sensor (PDT Output (Signal))	45.	-	-
23.	Br	Brake Pedal Sensor (PDT Output (Signal))	46.	B	Ground (GE06)

Operation and Leak Check Check all of the following items:

Component	Procedure
Integrated Brake Actuator Unit (IBAU) (A) and Power Supply Unit (PSU) (B)	Check brake operation by applying the brakes during a test drive. If the brakes do not operate properly, inspect the IBAU and power supply unit. Replace the IBAU and PSU assembly if it does not operate properly or if there are signs of leakage.
Inspect Piston Seal and Boot (B)	Check braking by applying the brakes. Look for damage or signs of brake fluid leakage. Replace the IBAU assembly if the pedal does not operate properly or if there is damage or signs of brake fluid leakage.
Brake Hoses (C)	Check for damage or signs of fluid leakage. Replace the brake hose with a new one if it is damaged or leaking.
Caliper Piston Seal and Piston Boot (D)	Check brake operation by depressing the brake pedal. Check for damage or signs of fluid leakage. If the pedal does not operate properly, the brakes do not brake properly, or there is damage or signs of fluid leakage, disassemble and inspect the brake caliper. Replace the boots and seals with new ones whenever the brake caliper is disassembled.