Two-Roller Soil Compactor Control for Smoother Vibration Passes

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Solution Overview

Problem

Existing soil compactors face challenges in achieving improved compaction results with efficient use, particularly in smoothing out surface unevenness generated during vibration compaction.

Innovation Solution

A soil compactor design with two rollers, where the trailing roller is operated in oscillation or static mode to smooth out surface troughs while the leading roller uses vibration compaction, and a control unit adjusts the vibration excitation based on movement direction to optimize compaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the trailing compactor roller is operated in vibration compaction mode, then compaction depth is improved, but surface unevenness and troughs are generated

Engineering Contradiction:
Improvecompaction depthVSAvoidsurface unevenness
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent applies different vibration modes to different rollers based on their position. The leading roller operates in vibration mode to create compaction, while the trailing roller operates in oscillation mode to smooth the surface. This local differentiation of function resolves the contradiction between achieving deep compaction and maintaining surface smoothness.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of having both rollers perform the same compaction function, the patent inverts the approach by having the trailing roller perform a smoothing function through oscillation mode. This reversal of the typical compaction sequence eliminates surface troughs while maintaining compaction effectiveness.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If vibration excitation is applied to both rollers, then compaction efficiency is improved, but energy consumption increases

Engineering Contradiction:
Improvecompaction efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies vibration excitation only to the leading roller while the trailing roller uses oscillation mode. This partial application of vibration reduces energy consumption compared to applying it to both rollers, while still achieving effective compaction through the coordinated action of the two rollers.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The trailing roller is designed to perform multiple functions through oscillation mode: it provides static compaction pressure and simultaneously smooths surface unevenness. This multi-functionality compensates for the reduced vibration input, maintaining compaction efficiency while reducing energy consumption.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Shape

If the compactor operates in oscillation mode, then surface smoothness is improved, but compaction depth is reduced

Engineering Contradiction:
Improvesurface smoothnessVSAvoidcompaction depth
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent segments the compaction process into two distinct functions performed by two separate rollers: the leading roller handles deep compaction through vibration mode, while the trailing roller handles surface smoothing through oscillation mode. This segmentation allows each roller to optimize its performance for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The leading roller performs preliminary deep compaction through vibration mode before the trailing roller applies oscillation mode for surface smoothing. This sequence ensures that compaction depth is achieved first, followed by surface refinement, resolving the contradiction between depth and smoothness.

Inventive Principle:
Principle #10Preliminary action

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

The solution effectively smooths surface unevenness and enhances compaction by alternating roller operations, ensuring a uniform compaction result with efficient use of the compactor.

Implementation Method 1

Each vibration excitation arrangement is designed to exert an oscillation torque on the associated compactor roller about its roller rotation axis in an oscillation vibration excitation mode

Methodology Applied
Scientific EffectOscillation torque: Torque Oscillator

Implementation Method 2

Each vibration excitation arrangement is designed to exert an oscillation torque on the associated compactor roller about its roller rotation axis in an oscillation vibration excitation mode and to exert a vibration force on the associated compactor roller substantially orthogonal to its roller rotation axis in a vibration vibration excitation mode

Methodology Applied
Scientific EffectVibration force: Vibration

Implementation Method 3

the oscillation unbalance masses of the oscillation arrangement are driven to rotate about their axes of rotation, or the vibration unbalance mass of the vibration arrangement is driven to rotate about its axis of rotation

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4249678B1Method for operating a soil compacting machine and soil compacting machine
Publication Date: 2025.10.15 HAMM AG
  • EP4249678B1 patent drawingFigure 1~2
  • EP4249678B1 patent drawingFigure 3

AI summary

In a method for operating a soil compactor (12), the soil compactor (12) comprising two compaction rollers (16, 22) arranged at a distance from each other in the direction of a longitudinal axis (L) of the soil compactor and rotatable about a respective roller rotation axis (W1, W2), each compaction roller (16, 22) is operable in an oscillation compaction mode, wherein in the oscillation compaction mode the vibration excitation arrangement (26, 28) assigned to a respective compaction roller (16, 22) is operated in oscillation-vibration excitation mode, in a vibration compaction mode, wherein in the vibration compaction mode the vibration excitation arrangement (26, 28) assigned to a respective compaction roller (16, 22) is operated in vibration-vibration excitation mode, and in a static compaction mode, wherein in the static compaction mode the vibration excitation arrangement (26, 28) assigned to a respective compaction roller (16, 22) is operated in vibration-vibration excitation mode. The vibration excitation arrangement (26, 28) associated with the compressor roller (16, 22) is deactivated.When the soil compactor (12) is moved in a plurality of successive compaction passes over a soil (10) to be compacted, with alternating movement of the soil compactor (12) essentially in the first direction of movement (B1) and essentially in the second direction of movement (B2), the trailing compaction roller is not operated in vibratory compaction mode during at least one pass.