Method and system of quantifying and managing steering command-response latency for an autonomous vehicle

1 . A method of quantifying and managing steering command-response latency for an autonomous vehicle, comprising:

autonomously driving a vehicle on a vehicle path;

detecting a trigger condition, wherein the trigger condition includes detecting a steering angle change greater than a predetermined threshold;

calculating, in real-time, average latencies of steering command-responses as a function of predetermined vehicle velocities in response to the detected trigger condition;

determining a change in the vehicle path;

determining an instant velocity to negotiate the determined change in the vehicle path;

selecting a calculated average latency of steering command-responses corresponding to a predetermined vehicle velocity same as the determined instant velocity;

issuing a direction change steering command to negotiate the determined change in the vehicle path, wherein the direction change steering command includes compensating for a latency in executing the direction change steering command based on the selected calculated average latency; and

executing the direction change steering command to negotiate the determined change in the vehicle path.

2 . The method of claim 1 , further comprising:

determining a current latency between issuing the direction change steering command to negotiate the determined change in the vehicle path and executing the direction change steering command; and

including the determined current latency and the determined instant velocity in calculating, in real-time, the average latencies of steering command-responses as a function of predetermined vehicle velocities in response to the detected trigger condition.

3 . The method of claim 1 , further comprising:

determining one of the calculated average latencies of steering command-responses exceeds a predetermined value threshold; and

initiating a vehicle health alert in response to the calculated average latencies of steering command-responses exceeding the predetermined value threshold.

4 . The method of claim 1 , wherein the plurality of predetermined vehicle velocities are predetermined discrete velocities.

5 . The method of claim 1 , wherein the plurality of predetermined vehicle velocities are predetermined velocity ranges.

6 . The method of claim 1 , wherein a latency of a steering command-response is an amount of time elapsed between a control module issuing a control command for a steering system to achieve a requested steering angle and the steering system completing an achievement of executing the requested steering angle.

7 . The method of claim 1 , wherein a latency of a steering command-response is an amount of time elapsed between a control module issuing a control command for a steering system to achieve a requested steering angle and the steering system achieving the requested steering angle.

8 . The method of claim 1 , wherein at least one of the latencies of the steering command-responses is determined by utilizing a cross-correlation function.

9 . The method of claim 3 , wherein the calculated average latencies of steering command-responses are weighted averages comprising a plurality of latencies determined over a period of time, wherein a more current determined latency includes a higher weight than a less current determined latency.

10 . The method of claim 9 , wherein less current latencies above a predetermined number are deleted as more current latencies are determined.

11 . A method of quantifying and managing steering command-response latency for an autonomous vehicle, comprising:

a. autonomously driving a vehicle at a plurality of predetermined velocities;

b. detecting a trigger condition, wherein the trigger condition includes detecting a steering angle change greater than a predetermined threshold;

c. issuing a plurality of control commands to achieve respective commanded steering angles at each of the plurality of predetermined velocities in response to the detected trigger condition;

d. achieving the respective commanded steering angles in response to the plurality of control commands;

e. determining a lag time between each of the issuing plurality of control commands to achieve respective commanded steering angles at each of the plurality of predetermined velocities and achieving the respective commanded steering angles in response to the detected trigger condition;

f. determining an average lag time for each of the plurality of predetermined velocities;

g. executing a current control command to achieve a current steering angle at one of the plurality of predetermined velocities, wherein the current control command includes compensating for the determined average lag time corresponding to the one of the plurality of predetermined velocities;

h. determining an averaged lag time to be greater than a predetermined threshold; and

i. issuing a warning in response to the averaged determined lag time being greater than the predetermined threshold.

12 . The method of claim 11 , wherein determining the lag time comprises utilizing a cross-correlation function.

13 . The method of claim 12 , wherein averaging the determined lag times for each of the plurality of predetermined velocities comprises assigning a weight, wherein a more current determined lag time includes a higher weight than a less current determined lag time.

14 . The method of claim 13 , wherein averaging the determined lag times for each of the plurality of predetermined velocities includes averaging a predetermined number of the more current determined lag times.

15 . The method of claim 14 , wherein the predetermined number of the more current determined lag times are stored in a buffer, and excess less current determined lag times above the predetermined number are deleted from the buffer.

16 . A non-transitory computer readable medium comprising instructions stored thereon for quantifying and managing steering command-response latency for an autonomous vehicle, that upon execution by a processor, cause the processor to:

autonomously drive a vehicle on a vehicle path;

detecting a trigger condition, wherein the trigger condition includes detecting a steering angle change greater than a predetermined threshold;

determine, in real-time, an average latency of steering command-responses for each of a plurality of predetermined vehicle velocities in response to the detected trigger condition;

determine a change in the vehicle path;

determine an instant velocity in response to the determined change in the vehicle path;

select a determined average latency having a predetermined vehicle velocity same as the instant velocity;

issue a direction change steering command to negotiate the determined change in the vehicle path, wherein the direction change steering command includes compensating for the selected determined average latency; and

execute the direction change steering command to negotiate the determined change in the vehicle path,

wherein the determined average latency is a weighted average comprising a plurality of latencies determined over a period of time, wherein a more current determined latency includes a higher weight than a less current determined latency.

17 . The non-transitory computer readable medium of claim 16 , further comprising instructions to cause the processor to:

determine one of the determined average latency of steering command-responses exceeding a predetermined value threshold; and

issue a vehicle health alert in response to the determined average latency of steering command-responses exceeding a predetermined value threshold.