Grain Cleaning Doppler Sensing for Adaptive Fan Control
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Solution Overview
Problem
Existing grain cleaning systems in combine harvesters rely on fan speed setpoints for auto-setting, which may not accurately represent the actual state of the material flowing through the cleaning system, leading to inefficiencies and potential blockages.
Innovation Solution
The system employs Doppler effect-based sensors to measure the speed of airborne grain and MOG, using ultrasonic transmitters and receivers to generate control signals that adjust fan speed and sieve settings based on real-time conditions, providing a more accurate representation of the material flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fan speed setpoint is used for auto-setting control, then control system is simple, but measurement precision of material flow state is insufficient
Solution Approach 1:
The patent replaces mechanical/fan-speed-based control with acoustic field-based measurement. Ultrasonic transmitters and receivers emit and detect acoustic waves to measure particle velocity and material flow state, substituting the mechanical fan speed sensor system with an acoustic measurement system that provides more precise real-time data on actual material conditions in the cleaning duct.
Solution Approach 2:
The patent introduces acoustic waves as an intermediary medium to measure material flow state. The ultrasonic transmitters and receivers use acoustic wave propagation through the cleaning airstream to indirectly measure particle velocity and material conditions, rather than directly measuring fan speed or material flow, providing a more accurate representation of actual cleaning system state.
2Productivity
If fan speed is increased to improve cleaning, then productivity increases, but material blockage risk increases
Solution Approach 1:
The patent implements a feedback control system where ultrasonic sensors continuously measure particle velocity and material flow state in the cleaning duct. This real-time feedback information is fed back to the control system, which adjusts fan speed dynamically - increasing it when material flow is good (improving productivity) and decreasing it when blockage risk is detected (maintaining reliability), thus resolving the contradiction between productivity and reliability.
Solution Approach 2:
The patent transitions from static fan speed control to dynamic, real-time adaptive control. The fan speed is continuously adjusted based on live ultrasonic measurements of material flow conditions, allowing the system to optimize cleaning efficiency when conditions permit while preventing blockages when material accumulation is detected, thereby balancing productivity and reliability.
3Quantity of substance
If high material volume is present in cleaning system, then productivity increases, but airflow speed decreases
Solution Approach 1:
The patent uses acoustic wave measurement to directly detect and measure the actual airflow speed and material volume conditions in the cleaning duct. The ultrasonic transmitters and receivers measure particle velocity and air flow characteristics regardless of material volume, providing accurate real-time data that reflects the true state of the cleaning system even under high material volume conditions where mechanical sensors would be less accurate.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of auto-setting adjustments, reducing grain loss and MOG separation issues by optimizing fan speed and sieve operation in response to real-time material conditions.
Implementation Method 1
The invention exploits the Doppler effect to generate control signals that are based upon the speed of the particles moving in the cleaning airstream. The base signal is reflected off of moving particles in the duct which primarily consist of a proportional mix of grain and MOG that is either airborne or carried on the sieve. The reflected signal is detected by the receiver and one or more Doppler frequencies are determined from the frequency of the base signal and the frequency of the reflected signal.
Data Source
Figure 1
Figure 2~13
Figure 3
AI summary
A sensing device (55) has a first ultrasonic transmitter (T1) which is adapted to transmit a first base signal (SB1) with a frequency (fB1). Airborne grain (G) and MOG (M) within the duct (50) of the grain cleaning system (30) reflect portions of the first base signal (SB1) causing reflected signals (SR) having a frequency (fR), wherein the reflected signals are detected by spaced-apart receivers (R1,R2). The ECU (101) is configured to modulate the first base signal (SB1) and the reflected signals (SR1,SR2) to obtain Doppler signals or frequencies from which an average particle velocity (vp) is determined. The particle velocity (vp) is used as an input parameter for the generation of control signals for the adjustment of various working units of the combine (10) including, by way of example, the fan (34) and sieves (38,39).