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US 11,698,355 B2Granted
Method of operating a gas sensing device, and corresponding gas sensing device
AssigneeSTMicroelectronics S.r.l.
InventorsFabio Passaniti, Enrico Rosario Alessi
Life of this patent
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Abstract
A method of operating a gas sensing device is described. The method includes receiving a signal indicative of a value of resistance of a gas sensing element, processing the signal received to compute a value of a gas concentration, performing a comparison of the value of gas concentration to a threshold, and, based on the outcome of a diagnosis procedure, setting the device to an alert signal issue state as a function of the outcome of the comparison. The diagnosis procedure includes computing a set of parameters indicative of the state of the gas sensor circuit, and classifying the gas sensor circuit in one of a first, a second and a third class based on the parameters.
Claims21
A method of operating a gas sensing device, the method comprising:
- receiving a first signal from a gas sensor circuit having a resistive gas sensing element, the first signal being indicative of a resistance value of the resistive gas sensing element;
- processing the first signal to compute a value of a gas concentration;
- comparing the value of gas concentration to a threshold value;
- and
- setting the gas sensing device to an alert signal issue state based on an outcome of the comparing, wherein the setting the gas sensing device to the alert signal issue state includes a diagnosis procedure, the diagnosis procedure including:
- computing a set of parameters indicative of a state of the gas sensor circuit;
- classifying the gas sensor circuit, based on values of the parameters in the set of parameters computed, in one of a first class, a second class and a third class indicative of the gas sensor circuit being faulty, degraded, or correctly operating, respectively;
- and
- in response to the gas sensor circuit being classified in the first class, disabling the setting the gas sensing device to the alert signal issue state;
- in response to the gas sensor circuit being classified in the second class, triggering a sensitivity correction procedure of the gas sensor circuit;
- in response to the gas sensor circuit being classified in the third class, enabling setting the gas sensing device to the alert signal issue state;
- and
- counting a number of consecutive executions of the sensitivity correction procedure.
10 more elements
A gas sensing device, comprising:
- a gas sensor circuit comprising a resistive gas sensing element;
- a control circuit coupled to the gas sensor circuit, the control circuit operable to control the gas sensor circuit by:
- applying a first signal on the gas sensor circuit;
- detecting a change of resistive value of the resistive gas sensing element in response to the first signal;
- determining an operation state of the gas sensor circuit based on the change of resistive value;
- and
- triggering a sensitivity correction procedure of the gas sensor circuit based on the operation state of the gas sensor circuit;
- and
- disabling the gas sensing device to issue an alert signal according to a measurement result of the gas sensor circuit.
6 more elements
A method, comprising:
- applying a current pulse on a MEMS gas sensor circuit having a resistive sensing element, the current pulse having a first stage and a second stage of different durations and different current values;
- detecting a change of resistive value of the resistive sensing element in response to the current pulse;
- determining a set of characteristics of the change of resistive value;
- and
- determining an operation state of the gas sensor circuit based on the set of characteristics;
- and
- disabling the gas sensor circuit to issue an alert signal according to a measurement result of the gas sensor circuit.
4 more elements
A method of operating a gas sensing device, wherein the gas sensing device comprises:
- a gas sensor circuit comprising a resistive gas sensing element;
- and
- a control circuit coupled to the gas sensor circuit,
- the method comprising:
- receiving at the control circuit a signal from the gas sensor circuit, the signal being indicative of a value of resistance of the resistive gas sensing element;
- processing the signal received from the gas sensor circuit to compute a value of a gas concentration;
- and
- performing a comparison of the value of gas concentration to a certain threshold value and setting the gas sensing device to an alert signal issue state as a function of an outcome of the comparison, wherein setting the gas sensing device to the alert signal issue state is conditioned on an outcome of a diagnosis procedure, the diagnosis procedure comprising:
- computing a set of parameters indicative of a state of the gas sensor circuit;
- classifying the gas sensor circuit as a function of the parameters in the set of parameters computed, in one of a first class, a second class and a third class indicative of the gas sensor circuit being faulty, degraded or correctly operating, respectively;
- and
- i) as a result of the gas sensor circuit being classified in the first class, disabling setting the gas sensing device to the alert signal issue state;
- ii) as a result of the gas sensor circuit being classified in the second class, triggering a sensitivity correction procedure of the gas sensor circuit and repeating the diagnosis procedure;
- and
- iii) as a result of the gas sensor circuit being classified in the third class, enabling setting the gas sensing device to the alert signal issue state;
- wherein the gas sensor circuit includes a resistive heater, and wherein computing the set of parameters indicative of the state of the gas sensor circuit comprises:
- applying a current pulse to the resistive heater;
- sensing the signal received from the gas sensor circuit as a result of application of the current pulse;
- and
- computing, as a function of the signal received, a value of resistance of the resistive gas sensing element and a value of slope of the signal received.
17 more elements
Dependencies are inferred from the claim text.