Property Classification through SensingProperty Classification through SensingMIDN 1/C Nicholas A. Dadds

Advisor: Dr. Svetlana Avramov-ZamurovicCo-Advisor: Dr. Kenneth A. Knowles Weapons and Systems Engineering

Material Type Classification Based on Capacitance

Material Mean Capacitance [% Full Scale]

Relative Uncertainty [ppm]

Air 0.59597 7

Wood 0.59931 7

PVC 0.59705 7

Aluminum 0.5732 50

* In order to avoid contact between the Aluminum material and the sensor a sheet of paper was placed in between the two for isolation*

Capacitive Sensor Setup Roughness Sensor

Stanton 400.V3

Temperature Sensor

MLX90247

Left GNDLeft Signal 5 V

Stylus

V oscope47k

Sensor

IC Cable

Rabbit 2000

Material

Capacitive Sensor Leads

AD7746*Converts capacitive reading to digital info for Rabbit*

.constdC

Dielectric constant of Material

Lead Length

PVC Roughness Profile

Aluminum Roughness Profile

Wood Roughness Profile

Signal Conditioning Circuit

*Output signal is an analog voltage

Internal SchematicsSignal Conditioning Circuit

The dielectric constant in the capacitance equation above varies depending on the type of material placed around the sensor. Therefore, each specific material type will produce a unique capacitive result. Under stable conditions, when calibrated for a specific set of materials this sensor is capable of providing data useful in determining what material is in the surrounding environment.

The plots shown above were obtained through the use of the Stanton 400.V3 Stylus. These plots show the general surface roughness of a given material and when viewed in comparison we get an idea of how the two surfaces relate to each other with respect to their roughness characteristics. We are able to compare the mean voltage value produced across a defined length of the material as well as the maximum peak voltage value, and the frequency of occurrence. Currently the roughness sensor is only connected so that it can obtain signals when moving to the left. However, for future work we will connect the right signal as well as design a device that will standardize the height and displacement of the sensor for each measurement.

Roughness Sensor

Stanton 400.V3

Left GNDLeft Signal 5 V

Stylus

V oscope47k

PVC Roughness ProfileAluminum Roughness Profile

Wood Roughness Profile

Signal Conditioning Circuit