Irrigation Drive Motor Cycle Control for Wear Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional center pivot irrigation systems experience excessive wear and tear and downtime due to the high frequency of on-and-off cycles of drive motors, which is necessary for maintaining constant speed, leading to inefficient water application and increased maintenance needs.
Innovation Solution
The system modifies the on-and-off cycle period inversely proportional to the average speed of the pivot arm, extending both on-time and off-time to reduce the frequency of cycles, thereby reducing wear on drive components and downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the speed timer cycles the drive motor on and off at a fixed cycle period (e.g., one minute), then the average speed of the pivot arm can be controlled, but the frequency of on-and-off cycles causes excessive wear and tear on drive components
Solution Approach 1:
The system dynamically adjusts the cycle period based on the desired average speed. Instead of using a fixed one-minute cycle period, the controller calculates and applies variable cycle periods that are longer at higher speeds and shorter at lower speeds, optimizing the balance between speed control precision and motor wear reduction
Solution Approach 2:
The invention changes the timing parameters of the on-and-off cycles by varying the cycle period as a function of desired average speed. The controller modifies both the on-time and off-time durations proportionally, maintaining the duty cycle percentage while extending the overall cycle period to reduce frequency of motor switching
2Measurement precision
If the on-and-off cycle frequency is increased to maintain constant speed, then speed control precision is improved, but irrigation downtime increases due to component failures
Solution Approach 1:
The system uses dynamic cycle period adjustment to maintain speed control precision without excessive cycling. By adapting the cycle period to the operational context, the system achieves adequate speed regulation while minimizing motor stress and associated failures that cause downtime
3Speed
If the drive motor is cycled more frequently, then the average speed can be maintained more accurately, but the number of on-and-off cycles increases causing inefficiency
Solution Approach 1:
The controller changes the timing parameters by adjusting the cycle period based on desired average speed. This allows the system to maintain accurate speed control with fewer, more efficient cycles rather than using high-frequency cycling that reduces overall irrigation productivity
Data Source
AI summary
A system for controlling the operation of a moving irrigation system lengthens the period of the on-and-off cycle specified by the speed timer to drive the pivot arm assembly. This reduces the frequency of the on-and-off cycles and thereby reduces wear and tear on the drive components. To modify the cycle period, a processor determines a modified on-time and a modified off-time having the same ratio of on-time to off-time as the speed timer to maintain the same average speed for the pivot arm assembly. The processor then controls operation of the pivot arm assembly to move in an on-and-off manner using the modified on-time and modified off-time.