Variable RPM Control for Agricultural Engine Load Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Agricultural machines like combine harvesters and forage harvesters operate at high fixed RPM, leading to high fuel consumption and noise, even when load is low, as they maintain constant engine speed regardless of load fluctuations, which is inefficient.

Innovation Solution

A self-propelled agricultural machine with a control unit that adjusts engine RPM based on assessed load, using a target RPM curve with sub-ranges for low, medium, and high loads, where RPM remains constant in low load, rises with load in medium load, and is determined by torque in high load, allowing for flexible operation and reduced fuel consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engine operates at high fixed RPM to ensure homogeneous crop processing and absorb load fluctuations, then crop processing quality is improved, but fuel consumption increases

Engineering Contradiction:
Improvecrop processing qualityVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic RPM control where the engine speed varies continuously based on actual load conditions. The control system adjusts RPM in real-time according to the three-load-range strategy, making the previously static parameter (fixed RPM) into a dynamic one that adapts to changing operational demands, thereby reducing fuel consumption while maintaining processing quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operational parameter of engine RPM from a fixed constant to a variable parameter with different target values across three load ranges. By modifying this key parameter dynamically - maintaining high RPM only when necessary (high load range) and reducing it during low and medium load conditions - the system achieves fuel savings without compromising crop processing homogeneity.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the engine operates at high fixed RPM to absorb load fluctuations, then crop flow stability is improved, but noise generation increases

Engineering Contradiction:
Improvecrop flow stabilityVSAvoidnoise
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The control system dynamically adjusts engine RPM based on actual load conditions rather than maintaining a fixed high speed. During low and medium load ranges where high noise generation occurs unnecessarily, the engine operates at lower RPM, significantly reducing noise while the control system maintains crop flow stability through appropriate RPM selection in each load range.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the engine operates at high fixed RPM to ensure homogeneous crop processing, then processing quality is improved, but engine efficiency decreases under low load

Engineering Contradiction:
Improvecrop processing qualityVSAvoidengine efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention changes the engine RPM parameter from a constant high value to a variable parameter with optimal values for different load conditions. In the low load range, the engine operates at reduced RPM values that match actual demand, eliminating energy waste from operating at unnecessarily high speeds while still maintaining sufficient RPM for quality crop processing when needed.

Inventive Principle:
Principle #35Parameter changes

4Use of energy by moving object

If the engine RPM is reduced to save fuel, then fuel consumption decreases, but the ability to absorb load fluctuations diminishes

Engineering Contradiction:
Improvefuel consumptionVSAvoidload fluctuation absorption
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system dynamically adjusts RPM based on real-time load conditions, allowing the engine to operate at lower fuel-efficient speeds during stable low and medium load conditions, while automatically increasing RPM when load fluctuations occur or high power demand arises. This dynamic response maintains the ability to absorb load fluctuations while maximizing fuel savings during steady-state operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system continuously monitors actual load conditions and uses this feedback to adjust target RPM accordingly. When load fluctuations are detected or power demand increases, the feedback mechanism triggers an RPM increase to maintain processing quality and absorb the fluctuation, while during stable low-load conditions, the feedback allows the engine to operate at fuel-efficient lower speeds.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2473018B1Agricultural machine with variable RPM control
Publication Date: 2019.05.01 CNH IND BELGIUM NV
  • EP2473018B1 patent drawingFigure 1
  • EP2473018B1 patent drawingFigure 2~3
  • EP2473018B1 patent drawingFigure 4~5

AI summary

The present invention relates to a self-propelled agricultural machine, comprising: ° elements (5) for gathering and/or processing crops; ° an engine (1) operable to travel the machine through a first driving mechanism (3) and to drive the operation of said elements through a second driving mechanism (4); and ° a control unit (6) for controlling engine RPM, characterised in that the control unit (6) is configured for controlling the engine RPM (ni) on the basis of a target RPM (ns), which is in turn based on an assessment of the imposed engine load (Ti), wherein in at least in one sub¬ range between 0% and 100% of the maximum load, the target RPM is a constantly rising function of said engine load. The present invention relates also to a method of controlling the RPM of the engine.