Driver warning in electric power steering systems

1. A steering system comprising:

a motor control system that sends a command to a motor;

a fault monitoring system that sets a fault indication flag by monitoring one or more components of the steering system;

a driver warning feedback system that generates a warning injection signal in response to the fault indication flag being set;

the motor control system further configured to generate a driver feedback by modifying the command to the motor using the warning injection signal, and sending the modified command to the motor; and

a failure monitoring and arbitration module that determines a type of the driver feedback based on the fault indication flag, wherein the type of the driver feedback indicates at least one of a haptic driver feedback and an acoustic driver feedback.

2. The steering system of claim 1 , wherein the command that is modified is a torque command.

3. The steering system of claim 1 , wherein the command that is modified is a current command.

4. The steering system of claim 1 , wherein the command that is modified is a voltage command.

5. The steering system of claim 1 , wherein the driver warning feedback system further comprises a fault duration module that monitors a duration of the fault indication being set, wherein the warning injection signal is determined based on the duration.

6. The steering system of claim 1 , further comprising an injection signal calculation module that computes the warning injection signal based on the type of the driver feedback to be provided, the computation including determining at least a frequency, and an amplitude of the warning injection signal.

7. The steering system of claim 6 , wherein the injection signal calculation module that determines at least a phase of the warning injection signal based on one or more control signals.

8. A method for providing driver warning feedback using a motor control loop in a steering system, the method comprising:

generating a command to be sent to a motor for generating torque;

receiving an indication flag that is indicative of a fault in one or more components of the steering system;

generating a warning injection signal based on the fault indication flag being set;

generating a driver feedback by modifying the command with the warning injection signal, and sending the modified command to the motor; and

determining, by a failure monitoring and arbitration module, a type of the driver feedback based on the fault indication flag, wherein the type of the driver feedback indicates at least one of a haptic driver feedback and an acoustic driver feedback.

9. The method of claim 8 , wherein the command that is modified is a torque command.

10. The method of claim 8 , wherein the command that is modified is a current command.

11. The method of claim 8 , wherein the command that is modified is a voltage command.

12. The method of claim 8 , wherein the command that is modified is at least one of a torque command, a current command, and a voltage command, and a result of an error simulation in a sensor signal of the steering system.

13. The method of claim 8 , further comprising, monitoring, by a fault duration module, a duration of the fault indication being set, wherein the warning injection signal is determined based on the duration.

14. The method of claim 8 , further comprising:

computing, by an injection signal calculation module, the warning injection signal based on the type of the driver feedback to be provided, the computation including determining at least a frequency and an amplitude of the warning injection signal.

15. The method of claim 8 , further comprising computing, by an injection signal calculation module, the warning injection signal based on the type of the driver feedback to be provided, the computation including determining at least a phase of the warning injection signal based on one or more control signals.

16. A driver warning feedback system comprising:

a failure monitoring and arbitration module configured to:

monitor a fault indication flag that is indicative of a fault in operation of one or more components of a steering system; and

determine to provide at least one of a haptic driver feedback and an acoustic driver feedback in response to the fault indication flag being set; and

an injection signal calculation module configured to:

compute a warning injection signal based on the at least one of the haptic driver feedback and the acoustic driver feedback to be provided, the computation including determining at least a frequency and an amplitude of the warning injection signal; and

send the warning injection signal to a motor control system of the steering system for using the warning injection signal as a command sent to a motor of the steering system to generate the driver feedback.

17. The driver warning feedback system of claim 16 , wherein the warning injection signal is superimposed on at least one of a torque command, a current command, a voltage command, and a sensor signal.

18. The driver warning feedback system of claim 16 , wherein the failure monitoring and arbitration module is further configured to determine a phase of the warning injection signal based on one or more control signals.

19. The driver warning feedback system of claim 16 , further comprising:

a fault duration module configured to:

monitor a duration of the fault indication flag being set; and

modify the warning injection signal in response to the duration exceeding a threshold duration.

20. The driver warning feedback system of claim 19 , wherein the threshold duration is a number of ignition cycles for which the fault indication flag is set.