Construction Machine Turn Radius Control on Slopes

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Solution Overview

Problem

Construction machines risk tipping when operating on side slopes due to center of gravity shifts or lateral forces during turns, necessitating a system to control turn radius and prevent tipping.

Innovation Solution

A control system comprising a grade sensor and controller that determines the slope and limits the turn radius of the machine by communicating with the steering system, setting threshold values to adjust the minimum turn radius based on the slope to prevent tipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the machine steers at a narrow radius on side slope, then the turning efficiency is improved, but the machine may tip over due to center of gravity shift or lateral forces

Engineering Contradiction:

Improveturning efficiencyVSAvoidmachine stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by making the turn radius limit adjustable based on operating conditions. The controller dynamically modifies the minimum turn radius parameter according to machine speed, slope angle, and articulation angle, allowing the system to adapt between narrow turns on level ground and wider turns on slopes, thus resolving the contradiction between turning efficiency and stability

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the turn radius parameter based on multiple operating parameters including machine speed, slope angle, and articulation angle. By continuously monitoring these parameters and adjusting the minimum turn radius accordingly, the system maintains optimal turning performance while preventing tipping on sloped terrain

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the turn radius is limited on uphill side, then the machine tipping risk is reduced, but the steering flexibility is restricted

Engineering Contradiction:

Improvemachine stabilityVSAvoidsteering flexibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system dynamically adjusts the turn radius limitation based on real-time operating conditions rather than imposing a fixed constraint. When the machine is on level ground or low slope, normal steering flexibility is maintained. When slope angle increases, the system progressively limits turn radius only in the uphill direction, preserving steering flexibility for downhill turns and level ground operations while providing stability protection when needed

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by differentiating between uphill and downhill turn radius limitations. The system selectively limits turn radius only toward the uphill side where tipping risk exists, while allowing unrestricted turns toward the downhill side. This selective approach maintains steering flexibility for safe maneuvers while preventing dangerous uphill turns on slopes

Inventive Principle:

Principle #3Local quality

3Reliability

If the minimum turn radius is increased on slope, then the machine tipping risk is reduced, but the turning performance deteriorates

Engineering Contradiction:

Improvemachine stabilityVSAvoidturning performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts the minimum turn radius based on machine speed and slope angle. At lower speeds where tipping risk is higher, a larger turn radius is enforced. As speed increases within safe operating parameters, the system allows progressively tighter turns. This dynamic adjustment maintains stability protection while optimizing turning performance for the current operating conditions

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies partial action by implementing turn radius limitation only when and where necessary - specifically on uphill turns on sloped terrain. On level ground or downhill turns, the system allows the machine to achieve its minimum design turn radius. This selective application of the constraint maintains turning performance where safe while providing protection where needed

Inventive Principle:

Principle #16Partial or excessive 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 system effectively prevents machine tipping by automatically adjusting the turn radius based on slope, reducing the risk of accidents and extending machine longevity by minimizing human error and operational concerns.

Implementation Method 1

a grade sensor configured to sense a value indicative of a slope of a hill upon which the working machine is traversing

Methodology Applied

Scientific EffectGravitation: Gravitation

Data Source

PatentUS11345398B2Machine turn radius control based on slope

Publication Date: 2022.05.31 CATERPILLAR PAVING PROD INC

AI summary

A machine that can comprise a steering system configured to direct movement of the machine and a control system operably coupled for communication with the steering system. The control system can comprise a grade sensor, and a controller configured to determine a slope from an uphill side of the machine to a downhill side of the machine based on sensed data from the grade sensor. The controller can be further configured to control the steering system to limit a turn radius of the machine toward the uphill side of the frame based on the determined slope.