Tire and tire sensor
In an example, a vehicle tire includes a tread portion, a sidewall portion, and a sensor module for estimating one or more parameters of the tire. The sensor module includes a detector patch that includes one or more capacitors, each of which has an electrostatic capacity that is variable due to at least deformation of each capacitor. The sensor module also includes an electronics unit connected to each capacitor and configured to control the sensor module. The detector patch is adhered to an inside of at least one of the tread portion or the sidewall portion. At least one of the capacitors is located on the inside of the at least one of the tread portion or the sidewall portion. The electronics unit is configured to estimate at least one of the parameters based on the electrostatic capacity of each capacitor.
1. A vehicle tire, comprising:
a tread portion;
a sidewall portion; and
a sensor module for estimating one or more parameters of the tire, the sensor module comprising:
a detector patch comprising one or more capacitors, each of which has an electrostatic capacity that is variable due to at least deformation of each capacitor; and
an electronics unit connected to each capacitor and configured to control the sensor module;
wherein:
the detector patch is adhered to an inside of at least one of the tread portion or the sidewall portion;
at least one of the capacitors is located on the inside of the at least one of the tread portion or the sidewall portion; and
the electronics unit is configured to estimate at least one of the parameters based on the electrostatic capacity of each capacitor;
wherein:
a first capacitor of the one or more capacitors has a length and a width;
the length exceeds the width;
the one or more capacitors comprise at least a first capacitor and a second capacitor;
a major axis direction of the first capacitor is oriented in a different direction than a major axis direction of the second capacitor; and
the major axis direction of the first capacitor is oriented orthogonally to the major axis direction of the second capacitor.
2. The vehicle tire of claim 1 , wherein the electronics unit is located on the inside of the tread portion or the sidewall portion.
3. The vehicle tire of claim 1 , wherein the capacitors are stacked as two or more layers or one layer in a thickness direction of the detector patch.
4. The vehicle tire of claim 1 , wherein each capacitor comprises at least a portion of each of three electrode layers, and two of the electrode layers are grounded.
5. The vehicle tire of claim 4 , wherein the grounded electrode layers have an electrically conductive mesh structure.
6. The vehicle tire of claim 4 , wherein:
the detector patch further comprises a perimeter electrode coupled between the grounded electrode layers;
a signal electrode layer of the three electrode layers is positioned between the grounded electrode layers; and
the grounded electrode layers and the perimeter electrode substantially encapsulate the signal electrode layer and form a Faraday cage substantially around the signal electrode layer.
7. The vehicle tire of claim 4 , wherein the three electrode layers are attached to the electronics unit by a conductive adhesive.
8. The vehicle tire of claim 1 , wherein each capacitor is charged by direct current, and a variation of the electrostatic capacity of each capacitor is calculated on an amount of discharged charge.
9. The vehicle tire of claim 1 , wherein: when the sensor module is attached to the tire, the length of the first capacitor is aligned within plus or minus 30 degrees of a direction of travel of the tire or within plus or minus 30 degrees of a direction perpendicular to the direction of travel of the tire.