Method for processing a temperature sensor signal
AssigneeKohler Co.
InventorVijit Paul Jayasheela
Life of this patent
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Abstract
A method for processing a pulse width modulated signal from a temperature sensor, wherein the signal varies non-linearly and non-exponentially with changes in temperature. An exponential equation is defined that is closely fitted to the relationship between a characteristic of the signal and the temperature. The signal from the sensor is processed by measuring the characteristic to produce a sensor value. That sensor value then is employed to solve the exponential equation which produces a value for the temperature.
Claims13
A method for processing a PWM signal output from a sensor, the sensor having a signal converter and a sensing element, the sensor located on and sensing an operating parameter of an apparatus, said method comprising:
- obtaining the PWM signal from the sensor, wherein the PWM signal has a characteristic that varies non-linearly and non-exponentially with changes in the operating parameter being sensed, and the PWM signal is pulse width modulated to indicate the operating parameter being sensed;
- defining an exponential equation that specifies a relationship between the PWM signal from the sensor and the operating parameter of the apparatus, wherein the exponential equation contains a term for a value of the PWM signal and a term for an initial value of the operating parameter;
- receiving the PWM signal from the sensor at a processor;
- measuring the characteristic of the PWM signal, with the processor, to produce the value of the PWM signal;
- and
- using the value of the PWM signal to solve the exponential equation which produces a current value for the operating parameter of the apparatus.
A method for processing a PWM signal from a temperature sensor on an engine, wherein the PWM signal has a characteristic that varies non-linearly and non-exponentially with engine temperature changes, said method comprising:
- defining an exponential equation that specifies a relationship between the PWM signal from the temperature sensor and the engine temperature, wherein the exponential equation contains a term for a value of the PWM signal and a term for the initial value of the operating parameter;
- receiving the PWM signal from the temperature sensor at a processor, wherein the signal is pulse width modulated to indicate the engine temperature;
- measuring the characteristic of the PWM signal, with the processor, to produce the value of the PWM signal;
- and
- using the value of the PWM signal to solve the exponential equation which produces a current value for the engine temperature.
A method for processing a pulse width modulated signal from a temperature sensor on an engine, wherein a portion of the signal has a duration that varies non-linearly and non-exponentially with engine temperature changes, said method comprising:
- defining an exponential equation that specifies a relationship between variation of the signal from the temperature sensor and the engine temperature, wherein the exponential equation is given by:
- T
- =
- T
- ∞
- +
- T
- i
- -
- T
- ∞
- e
- kt
- where T is a sensor value for the engine temperature, T ∞ is a steady state operating temperature of the engine, Tt is an initial temperature of the engine, k is an exponential constant, and t is the sensor value;
- receiving the signal from the temperature sensor;
- measuring a duration of the portion of the signal to produce the sensor value;
- and
- using the sensor value to solve the exponential equation which produces a value for the engine temperature.
Dependencies are inferred from the claim text.