Devices and methods for sensing tire and road conditions
Systems, devices, and methods are described for sensing tire, vehicle, and/or surface conditions using tire-mounted sensors. An example tire assembly includes a vehicle tire, a substrate adapted to deform in accordance with deformation of the vehicle tire, and a set of conductive liquid sensors coupled to the vehicle tire via the substrate, where an electrical resistance of the set of conductive liquid sensors changes in accordance with deformation of the substrate.
1 . A tire assembly, comprising:
a vehicle tire;
a substrate adapted to deform in accordance with deformation of the vehicle tire; and
a set of conductive liquid sensors coupled to the vehicle tire via the substrate, wherein an electrical resistance of the set of conductive liquid sensors changes in accordance with deformation of the substrate.
2 . The tire assembly of claim 1 , further comprising control circuitry coupled to the set of conductive liquid sensors, wherein the set of conductive liquid sensors are configured to provide road contact information for the vehicle tire to the control circuitry.
3 . The tire assembly of claim 2 , wherein the control circuitry is configured to determine one or more vehicle characteristics based on the electrical resistance of the set of conductive liquid sensors.
4 . The tire assembly of claim 1 , wherein the substrate is mechanical impedance matched with the vehicle tire.
5 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors have a thermal coefficient of expansion that is matched with a thermal coefficient of expansion of the vehicle tire.
6 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are attached to an interior or exterior surface of the vehicle tire.
7 . The tire assembly of claim 6 , further comprising an adhesive or bonding agent adapted to attach the set of conductive liquid sensors to the vehicle tire, wherein a coefficient of thermal expansion (CTE) for the adhesive or bonding agent is matched with a CTE for the vehicle tire.
8 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are embedded within the vehicle tire.
9 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are adapted to elongate to match changes in a shape of the vehicle tire.
10 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are composed of a conductive liquid metal.
11 . The tire assembly of claim 10 , wherein the conductive liquid metal is an alloy that is liquid at room temperature.
12 . The tire assembly of claim 10 , wherein the conductive liquid metal has a self-healing property while in liquid form.
13 . The tire assembly of claim 10 , wherein the conductive liquid metal has a stretchability of at least 10%.
14 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are deformable with an elongation of at least 30%.
15 . The tire assembly of claim 1 , wherein each sensor of the set of conductive liquid sensors comprises a liquid metal sensing electrode.
16 . The tire assembly of claim 15 , wherein an electrical resistance of the liquid metal sensing electrode changes proportional to the deformation of the substrate.
17 . The tire assembly of claim 1 , wherein the substrate is a polymer substrate.
18 . The tire assembly of claim 17 , wherein the polymer substrate has a mechanical stiffness that matches a stiffness modulus of the vehicle tire.
19 . The tire assembly of claim 1 , wherein the set of conductive liquid sensors are configured to have an output that is linear with a percentage of elongation of the set of conductive liquid sensors.
20 . The tire assembly of claim 1 , further comprising:
a tire pressure sensor configured to sense a pressure of the vehicle tire; and
control circuitry coupled to the set of conductive liquid sensors and the tire pressure sensor, wherein the control circuitry is configured to determine a tire load based on data from the tire pressure sensor and the set of conductive liquid sensors.