Agricultural Applicator PWM Control for Variable Ground Speed
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Solution Overview
Problem
Current agricultural systems face challenges in applying materials uniformly to a field, particularly when ground speed varies, leading to gaps or over-application due to fixed switching frequencies in pulse width modulated control signals.
Innovation Solution
A control system that senses ground speed and adjusts the switching frequency of pulse width modulated control signals to maintain a desired application pattern, allowing for variable application rates and patterns based on ground speed and material distribution requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed switching frequency is used in pulse width modulated control signals, then the control system is simple to operate, but gaps or over-application occur when ground speed varies
Solution Approach 1:
The control system dynamically adjusts the switching frequency of pulse width modulated control signals based on detected ground speed variations. The frequency is increased when ground speed decreases and decreased when ground speed increases, maintaining uniform material application despite speed fluctuations.
Solution Approach 2:
The system incorporates ground speed detection and uses this feedback to automatically adjust the switching frequency. The detected ground speed feeds back to the control system, which modifies the control signal frequency accordingly to compensate for speed variations and maintain application uniformity.
2Manufacturing precision
If the switching frequency is adjusted based on ground speed, then material application uniformity is improved, but the control system complexity increases
Solution Approach 1:
The system changes the switching frequency parameter of the pulse width modulated control signals in response to ground speed variations. By adjusting this key parameter dynamically, the system maintains material application uniformity without requiring complex hardware modifications.
Data Source
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AI summary
An agricultural machine (100) is disclosed. The agricultural machine (100) comprising: an applicator (109) that has an actuator (254) that is actuated to control application of liquid material to a surface (406) over which the agricultural machine travels; a ground speed sensor (304) configured to detect ground speed (328) of the agricultural machine and generate a ground speed signal indicative of the ground speed; and a control system (113) configured identify a target application pattern (260) for the liquid material and generate a pulse width modulated actuator control signal (702), to control the actuator, at a switching frequency (322) based on the ground speed signal and the target application pattern. Further, a method with such agricultural machine (100) is disclosed.