Microwave flow sensor for a harvester
First Claim
1. A flow sensor for sensing flow rate of moving crop material within a duct of a harvester, comprising:
- a microwave transceiver attached to the harvester for transmitting a transmitted microwave signal and receiving a reflected microwave signal;
an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal;
a quadrature mixer electronically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting a quadrature Doppler signal; and
an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output.
1 Assignment
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Accused Products
Abstract
A flow sensor for use in a harvester is disclosed. The flow sensor has a microwave transceiver for transmitting a microwave signal and receiving a reflected microwave signal, an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal, a quadrature mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting the quadrature Doppler signal, and an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output.
12 Citations
18 Claims
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1. A flow sensor for sensing flow rate of moving crop material within a duct of a harvester, comprising:
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a microwave transceiver attached to the harvester for transmitting a transmitted microwave signal and receiving a reflected microwave signal;
an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal;
a quadrature mixer electronically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting a quadrature Doppler signal; and
an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output. - View Dependent Claims (2, 3, 4)
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5. A flow sensor system for sensing flow rate of moving crop material, comprising:
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a microwave transparent duct for containing flowing crop material;
a microwave transceiver for transmitting a transmitted microwave signal towards the transparent duct and receiving a reflected signal;
an in-phase mixer electrically connected to the microwave transceiver for combining the transmitted microwave signal and the reflected microwave signal and outputting an in-phase Doppler signal;
a quadrature mixer electronically connected to the microwave transceiver for combining the transmitted microwave signal and a delayed reflected microwave signal and outputting a quadrature Doppler signal; and
an electronic circuit electrically connected to the in-phase mixer and the quadrature mixer and having a flow rate output. - View Dependent Claims (6, 7, 8, 9, 10)
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11. A method of measuring crop material flow rate within a duct comprising:
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transmitting a first microwave signal towards the crop material duct;
receiving a reflected microwave signal;
mixing the first microwave signal and the reflected microwave signal to produce an in-phase Doppler signal;
mixing the first microwave signal and a delayed reflected microwave signal to produce a quadrature Doppler signal;
sampling the in-phase Doppler signal and the quadrature Doppler signal to form a set of complex numbers;
computing a frequency domain spectrum having corresponding amplitude components and phase components;
computing a frequency domain power spectrum; and
summing the products of the components of the power spectrum and their corresponding frequencies to produce a crop material flow rate. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification