Self-powered sensor system for monitoring tire pressure
First Claim
1. A system for measuring air pressure in an inflatable automobile tire comprising:
- an inflatable tire mounted on a wheel and rotatable about a hub of an automobile;
a plurality of air pressure measurement sensors located within an inflatable portion of the mounted tire, each air pressure sensor being within its own individual housing, each individual housing being of a size sufficiently small to fit through a valve stem of the tire when the tire is being inflated with air;
a plurality of electromechanical transducers, having one coupled to each of the respective air pressure measurement sensors by a power circuit and positioned within each respective housing of the air pressure sensor to which the transducer is coupled and configured to generate power to be used by each of the respective air pressure sensors by electrical potential converted from mechanical acceleration experienced by movement of the electromechanical transducer;
a plurality of electric power storage devices within each housing respectively and coupled to the respective electromechanical transducer that is within the same housing as the electric power storage device for storing power produced by the respective electromechanical transducer;
a plurality of wireless transmission circuits, each one being respectively coupled to the respective electric power storage device within the same housing, and to each of the respective air pressure measurement sensors by a signal circuit and positioned within each respective housing of the air pressure sensor to which the respective pressure sensor is coupled and configured to wirelessly transmit an air pressure measurement signal received from the sensor, each respective electromechanical transducer being so small that the electromechanical transducer is incapable of producing sufficient power to operate the pressure sensor and wireless transmission circuit continuously and the wireless transmission circuit draws power from the electric power storage device during the time period of the wireless transmission operation;
a wireless receiver located on a chassis of the automobile and configured to receive a plurality of air pressure measurement signals from the respective wireless transmission circuits; and
an output interface coupled to the wireless receiver and configured to periodically output an air pressure measurement value for the tire.
1 Assignment
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Accused Products
Abstract
A self-powered tire pressure sensor device. The sensor device includes a power circuit, an air pressure measurement sensor, a signal circuit and a wireless transmission circuit. The power circuit converts mechanical acceleration experienced by the device into electrical potential using an electromechanical transducer. Mechanical acceleration due to collisions between the mobile sensor device and the wall of the tire while the tire is in motion cause the transducer to emit a small electrical charge. An electrical potential storage element in the power circuit accumulates and stores the charge as electrical potential. Alternatively the power circuit receives and converts electromagnetic energy into electrical potential. The electrical potential powers an air pressure measurement sensor within the tire. A signal circuit and wireless transmission circuit transmit the measurement to a chassis-mounted receiver, which makes the tire pressure measurement available to systems remote from the tire.
36 Citations
14 Claims
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1. A system for measuring air pressure in an inflatable automobile tire comprising:
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an inflatable tire mounted on a wheel and rotatable about a hub of an automobile; a plurality of air pressure measurement sensors located within an inflatable portion of the mounted tire, each air pressure sensor being within its own individual housing, each individual housing being of a size sufficiently small to fit through a valve stem of the tire when the tire is being inflated with air; a plurality of electromechanical transducers, having one coupled to each of the respective air pressure measurement sensors by a power circuit and positioned within each respective housing of the air pressure sensor to which the transducer is coupled and configured to generate power to be used by each of the respective air pressure sensors by electrical potential converted from mechanical acceleration experienced by movement of the electromechanical transducer; a plurality of electric power storage devices within each housing respectively and coupled to the respective electromechanical transducer that is within the same housing as the electric power storage device for storing power produced by the respective electromechanical transducer; a plurality of wireless transmission circuits, each one being respectively coupled to the respective electric power storage device within the same housing, and to each of the respective air pressure measurement sensors by a signal circuit and positioned within each respective housing of the air pressure sensor to which the respective pressure sensor is coupled and configured to wirelessly transmit an air pressure measurement signal received from the sensor, each respective electromechanical transducer being so small that the electromechanical transducer is incapable of producing sufficient power to operate the pressure sensor and wireless transmission circuit continuously and the wireless transmission circuit draws power from the electric power storage device during the time period of the wireless transmission operation; a wireless receiver located on a chassis of the automobile and configured to receive a plurality of air pressure measurement signals from the respective wireless transmission circuits; and an output interface coupled to the wireless receiver and configured to periodically output an air pressure measurement value for the tire. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for remotely sensing air pressure in an inflatable tire comprising:
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receiving a plurality of housings into a value stem of the inflatable tire, the value stem having an air inlet port to receive air to inflate the tire with air, the housing having therein a power generation circuit, an electric power storage device, an air pressure sensor and a remote transceiver; moving each of the plurality of housings and the respective power generation circuits within its respective housing relative to the tire as the tire rotates, the power generation circuit being fully inside of the tire; converting in a power circuit inside the tire energy from the power generation circuit into electrical energy based on movement of the power generation circuit relative to the tire; driving the air pressure measurement sensor electrically connected to the power circuit using the converted electrical energy to determine the air pressure inside the tire; storing electrical energy created by the respective power generation circuits in the respective electric power storage devices located within each the respective housings; measuring the air pressure inside the tire using the air pressure measurement sensor; and wirelessly transmitting from a first remote transceiver of the plurality of remote transceivers electrically connected to a first respective air pressure measurement sensor in a first housing to a base transceiver outside the tire a signal encoded with a value corresponding to the measured air pressure at first time period after a threshold amount of electricity has been stored in a first electric power storage device of the plurality of electric power storage devices; wirelessly transmitting from a second remote transceiver of the plurality of remote transceivers electrically connected to a second respective air pressure measurement sensor in a second housing of the plurality of housings to the base transceiver outside the tire a signal encoded with a value corresponding to the measured air pressure at second time period after a threshold amount of electricity has been stored in a second electric power storage device of the plurality of electric power storage devices. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification