Installation structure of pedal stroke sensor
An installation structure of a pedal stroke sensor of an integrated dynamic brake (IDB) system is disclosed. The IDB system includes a hydraulic block, a hydraulic pressure generator, and an electronic control unit (ECU). The hydraulic block includes not only a master cylinder connected to a brake pedal but also a plurality of passages and valves needed to adjust a brake hydraulic pressure. The hydraulic pressure generator includes a motor that is connected to the hydraulic block and operates by an output signal of a detection sensor for sensing displacement of the brake pedal, thereby generating brake hydraulic pressure. The ECU controls the motor and the valves based on pressure information and pedal displacement information. The installation structure of the pedal stroke sensor includes a magnet installed in a piston that slidably moves within the master cylinder by interacting with the brake pedal. The detection sensor includes a first sensor and a second sensor that are spaced apart from each other by a predetermined distance in a movement direction of the piston in a manner that the first and second sensors detect a magnetic flux density of the magnet in response to movement of the piston.
1. An installation structure of a pedal stroke sensor of an integrated dynamic brake (IDB) system which includes a hydraulic block, a hydraulic pressure generator, and an electronic control unit (ECU), wherein the hydraulic block includes a master cylinder connected to a brake pedal and a plurality of passages and valves needed to adjust a brake hydraulic pressure, the hydraulic pressure generator includes a motor that is connected to the hydraulic block and operates by an output signal of a detection sensor for sensing displacement of the brake pedal, thereby generating brake hydraulic pressure, and the electronic control unit (ECU) controls the motor and the valves based on pressure information and pedal displacement information, the installation structure comprising:
a magnet installed in a piston that slidably moves within the master cylinder by interacting with the brake pedal,
wherein the detection sensor includes a first sensor and a second sensor that are spaced apart from each other by a predetermined distance in a movement direction of the piston in a manner that the first and second sensors detect a magnetic flux density of the magnet in response to movement of the piston and a first part detected by the first sensor and a second part detected by the second sensor at least partially overlap each other.
2. The installation structure of the pedal stroke sensor according to claim 1 , wherein the first sensor and the second sensor are installed in a printed circuit board (PCB) provided in the electronic control unit (ECU).
3. The installation structure of the pedal stroke sensor according to claim 1 , wherein the first sensor and the second sensor are implemented as a Hall Integrated Circuit (Hall IC) to detect a change in magnetic force.
4. The installation structure of the pedal stroke sensor according to claim 1 , wherein the detection sensor is configured to detect an absolute position of the piston based on a specific position where a first position detected by an output value of the first sensor and a second position detected by an output value of the second sensor overlap each other during movement of the piston.
5. The installation structure of the pedal stroke sensor according to claim 1 , wherein:
when any one of the first sensor and the second sensor abnormally operates, any one of the first sensor and the second sensor which does not abnormally operate is configured to detect the magnetic flux density of the magnet in response to movement of the piston.
6. The installation structure of the pedal stroke sensor according to claim 1 , wherein the detection sensor is configured to detect an absolute position of the piston based on an overlapped part of the first part detected by the first sensor and the second part detected by the second sensor.