A pressure modulator for an ABS system includes a housing that which has a hydraulic inlet and a hydraulic outlet that are interconnected via a hydraulic line; a volume accumulator that increases a volume of the hydraulic line during an activated anti-lock function, a linear drive for opening the volume accumulator and an electronic circuit that controls the linear drive and is disposed in the housing.

In accordance with some embodiments, the present disclosure provides A brake system for braking a vehicle using one or both of a main braking system and a redundancy braking system, the brake system comprising: a brake demand detecting unit configured to detect a driver's brake demand; an electronic control unit comprising: a pressure controller configured to control a pressure inside a master cylinder in response to a value detected by the brake demand detecting unit, wherein the internal pressure of the master cylinder is controlled by generating an electrical signal for a first demand current; a motor position controller configured to control a position of a motor by generating an electrical signal for a second demand current; and a current controller configured to control the current of the motor in response to an electrical signal received from one of the motor position controller and the pressure controller; a position detecting unit configured to detect a position of a rotor of the motor; and a pressure detecting unit configured to sense the internal pressure of the master cylinder.

The disclosure provides an anti-lock brake device including an oil pressure tank, a first piston and a second piston. The oil pressure tank has an internal space, an oil inlet and an oil outlet that are connected to one another. The first piston is slidably located in the internal space, and has a first oil channel penetrating a contact portion of the first piston and connected to the oil inlet. The second piston is slidably located in the internal space and includes a push portion, and an outer diameter of the push portion is smaller than that of the contact portion. When the second piston is in a closed position, a chamber having a first unoccupied volume is formed in the internal space. When the second piston is moved from the closed position to a depressurized position, the first volume of the chamber is increased to a second volume.

The disclosure provides an anti-lock brake device including an oil pressure tank, a first piston and a second piston. The oil pressure tank has an internal space, an oil inlet and an oil outlet that are connected to one another. The first piston is slidably located in the internal space, and has a first oil channel penetrating a contact portion of the first piston and connected to the oil inlet. The second piston is slidably located in the internal space and includes a push portion, and an outer diameter of the push portion is smaller than that of the contact portion. When the second piston is in a closed position, a chamber having a first unoccupied volume is formed in the internal space. When the second piston is moved from the closed position to a depressurized position, the first volume of the chamber is increased to a second volume.

A pressure modulator for an ABS system includes a housing that which has a hydraulic inlet and a hydraulic outlet that are interconnected via a hydraulic line; a volume accumulator that increases a volume of the hydraulic line during an activated anti-lock function, a linear drive for opening the volume accumulator and an electronic circuit that controls the linear drive and is disposed in the housing.