Electric seat motor absolute sensor diagnostics
A method for sensor diagnostics in a seat suspension system includes: generating, by a first rotational position sensor, a motor position signal representing a rotational position of a motor shaft, the motor shaft being coupled to an output shaft, such that rotation of the motor shaft causes rotation of the output shaft; generating, by a second rotational position sensor, an output signal representing a rotational position of the output shaft coupled to a suspension mechanism to move a vehicle seat relative to a vehicle body; determining a diagnostic indicator value as a function of the motor position signal and the output signal; and determining, based on the diagnostic indicator value, an accuracy of the output signal to represent the rotational position of the output shaft.
1 . A method for sensor diagnostics in a seat suspension system, comprising:
generating, by a first rotational position sensor, a motor position signal representing a rotational position of a motor shaft, the motor shaft being coupled to an output shaft, such that rotation of the motor shaft causes rotation of the output shaft;
generating, by a second rotational position sensor, an output signal representing a rotational position of the output shaft coupled to a suspension mechanism to move a vehicle seat relative to a vehicle body, wherein the output signal includes a sine output and a cosine output, each of the sine output and the cosine output representing the rotational position of the output shaft;
determining a diagnostic indicator value as a function of the motor position signal and the output signal; and
determining, based on the diagnostic indicator value, an accuracy of the output signal to represent the rotational position of the output shaft.
2 . The method of claim 1 , wherein determining the accuracy of the output signal to represent the rotational position of the output shaft further comprises comparing the diagnostic indicator value to a tolerance value.
3 . The method of claim 2 , wherein the tolerance value includes an upper tolerance value; and comparing the diagnostic indicator value to the tolerance value includes determining if the diagnostic indicator value is greater than the upper tolerance value.
4 . The method of claim 2 , wherein the tolerance value includes a lower tolerance value; and comparing the diagnostic indicator value to the tolerance value includes determining if the diagnostic indicator value is less than the lower tolerance value.
5 . The method of claim 1 , wherein determining the diagnostic indicator value includes calculating a ratio of the output signal to the motor position signal.
6 . A seat suspension system, comprising:
a suspension mechanism coupling a vehicle seat to a vehicle body;
an output shaft coupled to the suspension mechanism to move the vehicle seat relative to the vehicle body;
a motor shaft coupled to a gear box and to drive the output shaft;
a first rotational position sensor configured to measure a rotational position of the motor shaft and to generate a motor position signal representing the rotational position of a motor shaft;
a second rotational position sensor configured to measure a rotational position of the output shaft and to generate an output signal representing the rotational position of the output shaft; and
a controller configured to:
determine a diagnostic indicator value as a function of the motor position signal and the output signal; and
determine, based on the diagnostic indicator value, an accuracy of the output signal to represent the rotational position of the output shaft.
7 . The seat suspension system of claim 6 , wherein the output signal includes a sine output and a cosine output, each of the sine output and the cosine output representing the rotational position of the output shaft.
8 . The seat suspension system of claim 6 , wherein determining the accuracy of the output signal to represent the rotational position of the output shaft further comprises the controller being configured to compare the diagnostic indicator value to a tolerance value.
9 . The seat suspension system of claim 8 , wherein the tolerance value includes an upper tolerance value; and comparing the diagnostic indicator value to the tolerance value includes the controller being configured to determine if the diagnostic indicator value is greater than the upper tolerance value.
10 . The seat suspension system of claim 8 , wherein the tolerance value includes a lower tolerance value; and comparing the diagnostic indicator value to the tolerance value includes the controller being configured to determine if the diagnostic indicator value is less than the lower tolerance value.
11 . The seat suspension system of claim 6 , wherein determining the diagnostic indicator value includes calculating a ratio of the output signal to the motor position signal.
12 . A controller for a seat suspension system comprising:
a processor; and
a memory including instructions that, when executed by the processor, cause the processor to:
receive, from a first rotational position sensor, a motor position signal representing a rotational position of a motor shaft, the motor shaft being coupled to an output shaft, such that rotation of the motor shaft causes rotation of the output shaft;
receive, from a second rotational position sensor, an output signal representing a rotational position of the output shaft coupled to a suspension mechanism to move a vehicle seat relative to a vehicle body;
determine a diagnostic indicator value as a function of the motor position signal and the output signal;
determine, based on the diagnostic indicator value, an accuracy of the output signal to represent the rotational position of the output shaft;
determine the diagnostic indicator value indicating an unhealthy or faulted condition; and
automatically perform, in response to determining the diagnostic indicator value indicating an unhealthy or faulted condition, a responsive action including at least one of: producing a warning, or operating the seat suspension system in a mode that does not use the second rotational position sensor.
13 . The controller of claim 12 , wherein the output signal includes a sine output and a cosine output, each of the sine output and the cosine output representing the rotational position of the output shaft.
14 . The controller of claim 12 , wherein determining the accuracy of the output signal to represent the rotational position of the output shaft further comprises the controller being configured to compare the diagnostic indicator value to a tolerance value.
15 . The controller of claim 14 , wherein the tolerance value includes an upper tolerance value; and comparing the diagnostic indicator value to the tolerance value includes the controller being configured to determine if the diagnostic indicator value is greater than the upper tolerance value.
16 . The controller of claim 14 , wherein the tolerance value includes a lower tolerance value; and comparing the diagnostic indicator value to the tolerance value includes the controller being configured to determine if the diagnostic indicator value is less than the lower tolerance value.
17 . The controller of claim 12 , wherein determining the diagnostic indicator value includes calculating a ratio of the output signal to the motor position signal.