Electric power steering apparatus having redundancy for enhancing safety
The present disclosure aims to provide an electric power steering apparatus which is improved in reliability compared to an existing electric power steering apparatus by configuring redundancy for an electronic system therein. An embodiment provides a electric power steering apparatus including: a four-channel torque sensor including two independent dual die ICs; a four-channel steering angle sensor including two independent dual die ICs; a four-channel motor position sensor including two independent dual die ICs; a dual-wound Brushless AC (BLAC) motor including a first winding motor and a second winding motor therein; a first Electronic Control Unit (ECU); a second ECU; and a selector configured to select an ECU that controls steering among the first ECU and the second ECU. The first ECU and the second ECU are supplied with power from separate power supply devices which are separated from each other, the first winding motor of the dual-wound BLAC motor is connected to an inverter of the first ECU, and the second winding motor of the dual-wound BLAC is connected to an inverter of the second ECU.
1. An electric power steering apparatus comprising:
a four-channel torque sensor comprising two independent dual die ICs;
a four-channel steering angle sensor comprising two independent dual die ICs;
a four-channel motor position sensor comprising two independent dual die ICs;
a dual-wound Brushless AC (BLAC) motor comprising a first winding motor and a second winding motor therein;
a first Electronic Control Unit (ECU);
a second ECU; and
a selector configured to select an ECU that controls steering among the first ECU and the second ECU,
wherein the first ECU and the second ECU are supplied with power from separate power supply devices which are separated from each other, and
the first winding motor of the dual-wound BLAC motor is connected to an inverter of the first ECU, and the second winding motor of the dual-wound BLAC is connected to an inverter of the second ECU.
2. The electric power steering apparatus of claim 1 , wherein the four-channel torque sensor transmits a first torque signal and a second torque signal to the first ECU, and transmits a third torque signal and a fourth torque signal to the second ECU.
3. The electric power steering apparatus of claim 1 , wherein the four-channel motor position sensor transmits a first motor position signal and a second motor position signal to the first ECU, and transmits a third motor position signal and a fourth motor position signal to the second ECU.
4. The electric power steering apparatus of claim 2 , wherein the selector selects the second ECU as the ECU that controls the steering when a difference occurs between signal values of the first torque signal and the second torque signal.
5. The electric power steering apparatus of claim 3 , wherein the selector selects the second ECU as the ECU that controls the steering when a difference occurs between signal values of the first motor position signal and the second motor position signal.
6. The electric power steering apparatus of claim 1 , wherein the selector selects the second ECU as the ECU that controls the steering when a voltage of a battery power source supplied to the first ECU is lower than a preset threshold voltage.
7. The electric power steering apparatus of claim 1 , wherein, in a case in which the second ECU is selected by the selector as the ECU that controls the steering, the second ECU receives the first torque signal and the second torque signal from the first ECU through CAN communication when a difference occurs between signal values of the third torque signal and the fourth torque signal, and calculates a torque value based on same torque signal value when two or more torque signals among the first torque signal, the second torque signal, the third torque signal, and the fourth torque signal have the same torque signal value.
8. The electric power steering apparatus of claim 1 , wherein the first ECU and the second ECU is capable of controlling the steering simultaneously.
9. The electric power steering apparatus of claim 8 , wherein an output of the first winding motor controlled by the first ECU and an output of the second winding motor controlled by the second ECU are equal to each other.
10. The electric power steering apparatus of claim 8 , wherein the four-channel torque sensor transmits a first torque signal and a second torque signal to the first ECU, and transmits a third torque signal and a fourth torque signal to the second ECU.
11. The electric power steering apparatus of claim 8 , wherein the four-channel motor position sensor transmits a first motor position signal and a second motor position signal to the first ECU, and transmits a third motor position signal and a fourth motor position signal to the second ECU.
12. The electric power steering apparatus of claim 10 , wherein the selector selects only the second ECU as the ECU that controls the steering when a difference occurs between signal values of the first torque signal and the second torque signal.
13. The electric power steering apparatus of claim 11 , wherein the selector selects only the second ECU as the ECU that controls the steering when a difference occurs between signal values of the first motor position signal and the second motor position signal.
14. The electric power steering apparatus of claim 8 , wherein the selector selects only the second ECU as the ECU that controls the steering when a voltage of a battery power source supplied to the first ECU is lower than a preset threshold voltage.