Siemens Automotive S.a.

Siemens Canada Limited

Siemens Vdo Automotive Corporation

Laurent Fabre

Georges Fonzes

Pierre Calvairac

The invention relates to a method for filtering information emitted, on the basis of pressure measurements taken by a pressure sensor mounted on a wheel of a vehicle equipped with a tire, to a central unit mounted on the vehicle. According to this method, a value representative of the pressure of the air in the tire is measured periodically, with a period &#x3b8;, and from this any possible variations &#x394;P in pressure between the values of the pressures successively measured are deduced; in parallel, with the same period &#x3b8;, a value representative of the temperature of the air in the tire is measured. In addition, when there is a variation &#x394;P in pressure between two measured pressure values, that is greater in terms of absolute value than a predetermined threshold Sp, the variation &#x394;T between the two temperature values measured at the same instants as the measured pressures is calculated. The emission of a signal representative of a variation in pressure to the central unit is commanded only if the comparative change in the pressure and in the measured temperature might be representative of a variation of the amount of air in the tire.

Method and device for filtering information emitted by a pressure sensor mounted on a wheel of a vehicle

A method of leak detection in a closed vapor handling system of an automotive vehicle, wherein an engine is shut off, implemented by a system, the method including obtaining a start temperature and start pressure, providing an evaluation temperature, calculating a temperature differential between the start temperature and the evaluation temperature, evaluating whether a pressure switch is closed if the temperature differential is greater than a temperature control value, incrementing a time counter if the pressure switch is not closed and comparing the time counter to a time control value if the pressure switch is not closed. The system includes a pressure switch, a temperature sensing element, and a processor operatively coupled to the pressure switch and the temperature sensing element and receiving, respectively, pressure and temperature signals therefrom, wherein the processor calculates a temperature differential between a start temperature and an evaluation temperature, evaluates whether the pressure switch is closed, increments a time counter, and compares the time counter to the time control value.

Leak detection in a closed vapor handling system using a pressure switch, temperature and statistics

A method of leak detection in a closed vapor handling system of an automotive vehicle, wherein an engine is shut off, implemented by a system, the method including providing pressure switch and a time counter, closing a shut off valve, waiting for a no test delay, evaluating whether the pressure switch is closed, incrementing the time counter if the pressure switch is open and comparing the time counter to a time control value if the pressure switch is open. The system includes a pressure switch, a shut off valve and a processor operatively coupled to the pressure switch and the shut off valve. The processor receives pressure signals from the pressure switch and sends signals to the shut off valve, wherein the processor closes the shut off valve, waits for a no test delay, determines whether the pressure switch is closed, increments a time counter and compares the time counter to a time control value.

Leak detection in a closed vapor handling system using a pressure switch and time

A method of leak detection in a closed vapor handling system of an automotive vehicle while an engine is running, implemented by a system, the method including providing a pressure sensing element that obtains at least one pressure signal, closing a control valve and a shut off valve to seal the system from the engine and an atmosphere, generating a vacuum by opening the control valve, analyzing the at least one pressure signal at threshold times, comparing the at least one pressure signal to at least one pressure control value, and determining a leak condition if the at least one pressure signal is not less than the at least one pressure control value. The system including a pressure sensing element, a control valve, a shut off valve, a processor operatively coupled to the pressure sensing element and the shut off valve and receiving pressure signals from the pressure sensing element and sending signals to the control valve and the shut off valve. The processor closes the control valve and the shut off valve, generates a vacuum, depressurizes the system using the vacuum, controls the vacuum by opening the control valve, analyzes the pressure signal at threshold times, compares the pressure signal to pressure control values, and determines a leak condition.

Leak detection a vapor handling system

A method of diagnosing components used for leak detection in a closed vapor handling system of an automotive vehicle, implemented by a system, the method including providing leak detection components including a pressure switch that moves at a given relative vacuum, a control valve that operates to allow and prevent flow therethrough, and a shut off valve that operates to allow and prevent flow therethrough, running an engine, determining whether the pressure switch is closed, purging a canister, specifying a fail condition if the control valve is inoperative after purging, ascertaining whether the control valve is inoperative in a flow-through condition or inoperative in a non-flow-through condition if a fail condition is specified, specifying a pass condition if the control valve is functioning after purging, determining whether the shut off valve and pressure switch are malfunctioning if a pass condition is specified based on whether the pressure switch is open, and displaying an error if a component is malfunctioning. The system includes a pressure switch, a control valve, a shut off valve, and a processor operatively coupled to the pressure sensing element, the control valve, and the shut off valve and receiving pressure signals from the pressure sensing element and sending signals to the control valve and the shut off valve, wherein the processor runs an engine, determines whether the pressure switch is closed, purges a canister, specifies a fail condition if the control valve is inoperative, ascertains whether the control valve is inoperative in a flow-through condition or inoperative in a non-flow-through condition, specifies a pass condition if the control valve is functioning, determines whether the shut off valve and the pressure switch are malfunctioning, and displays an error if at least one of the pressure switch, the shut off valve, and the control valve is malfunctioning.

Diagnosis of components used for leak detection in a vapor handling system

A method of leak detection in a closed vapor handling system of an automotive vehicle, wherein an engine is shut off, implemented by a system, the method including obtaining a start temperature and start pressure, providing an evaluation temperature, calculating a temperature differential between the start temperature and the evaluation temperature, incrementing a time counter if the temperature differential is greater than a temperature control value, computing a pressure differential between the start pressure and an evaluation pressure, and comparing the time counter to a time control value if the pressure differential is not greater than a pressure control value. The system includes a pressure sensing element, a temperature sensing element, and a processor operatively coupled to the pressure sensing element and the temperature sensing element and receiving, respectively, pressure and temperature signals therefrom, wherein the processor calculates a temperature differential between a start temperature and an evaluation temperature, increments a time counter, computes a pressure differential between a start pressure and an evaluation pressure, and compares the time counter to the time control value.

Leak detection in a closed vapor handling system using pressure, temperature and time

A method of leak detection in a closed vapor handling system of an automotive vehicle, implemented by a system, the method including providing a vacuum detection component having a microcontroller operatively coupled to actuators and sensors, receiving at least one sensor signal from the sensors to the vacuum detection component, processing the at least one sensor signal in the microcontroller, sending output to an engine management system based on the at least one processed sensor signal, processing the output in the engine management system operatively coupled to a control valve, transmitting input from the engine management system to the vacuum detection component based on the processed output, and sending actuator signals from the microcontroller to the actuators. The system including a vacuum detection component having a microcontroller operatively coupled to actuators and sensors, the microcontroller sending and receiving, respectively, signals therefrom and a processor communicating with the microcontroller, the microcontroller processing the signals and sending output based on the processed signals to the processor, the processor processing the output and transmitting input to the microcontroller based on the processed output.

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Portet sur Garonne, France

Laurent Fabre