Construction Machine Stability Control via Dynamic Actuator Scaling

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Solution Overview

Problem

Construction machines face instability issues due to improper operator commands and equipment, leading to risky situations such as rollovers and tipping, which existing control systems cannot effectively prevent, especially when operators ignore warnings.

Innovation Solution

A method and system that utilize sensors to monitor and estimate both static and dynamic stability conditions of construction machines, generating control signals to actively manage operational components, such as hydraulic or electric actuators, to prevent unstable situations by scaling operational accelerations and velocities based on the machine's center of gravity and stability index.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If passive warning systems are used to alert operators of unstable conditions, then operators are informed of critical situations, but the system cannot prevent risky or fatal situations if operators ignore warnings

Engineering Contradiction:
Improvesafety prevention capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system continuously monitors machine stability parameters (center of gravity position, stability index) and feeds this information back to actively adjust operational commands. When instability is detected, the system automatically scales down acceleration and velocity commands, creating a closed-loop feedback mechanism that prevents rather than merely warns of unstable conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system acts as an intermediary between the operator's commands and the machine's actual movement. By inserting this intermediate control layer, the system can modify operational commands in real-time based on stability conditions, scaling down aggressive commands when necessary while still allowing the operator to control the machine.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If operational commands are restricted to maintain stability, then machine stability is improved, but operator productivity and machine performance may be reduced

Engineering Contradiction:
Improvemachine stabilityVSAvoidoperational efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The control system dynamically adjusts the scaling factor based on real-time stability conditions rather than applying fixed restrictions. When the machine is in a stable state, full operational commands are allowed, maximizing productivity. When instability is detected, the system dynamically scales down commands proportionally, maintaining the best possible balance between stability and performance.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameters of operational commands (acceleration and velocity) based on stability conditions. By scaling these parameters dynamically rather than imposing hard limits, the system maintains operational efficiency while preventing unstable conditions. The scaling factor adjusts continuously based on the stability index and center of gravity position.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If acceleration scaling is applied to prevent instability, then dynamic stability is improved, but the machine's responsiveness to operator commands is reduced

Engineering Contradiction:
Improvedynamic stabilityVSAvoidresponse speed
Core Design Contradiction:
Stability of the object's compositionVSSpeed

Solution Approach 1:

The system applies partial scaling to acceleration commands rather than complete restriction. By scaling down acceleration proportionally based on stability conditions rather than blocking it entirely, the system maintains dynamic stability while preserving enough responsiveness for safe and effective operation. The scaling is excessive only when necessary to prevent instability.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4170100B1Method and system for controlling the stability conditions of a machine
Publication Date: 2024.04.17 YANMAR HLDG CO LTD
  • EP4170100B1 patent drawingFigure 1
  • EP4170100B1 patent drawingFigure 2
  • EP4170100B1 patent drawingFigure 3

AI summary

Method (100) for controlling the stability conditions of a machine (1) moveable on a ground (G) having at least an operational component (2), in particular a hydraulic cylinder, for moving a portion (3) of the machine (1), and being maneuvered by an operator through operational commands, the method (100) comprising acquiring (S101) at least a first sensor signal (4) defining the position of the portion of the machine (1); acquiring (S102) at least a second sensor signal (5) defining a variation of the position of the portion of the machine (1) relative to the ground (G); acquiring (S103) at least a command signal (6) defining the operational commands of the operator for actuating the operational component (2) and for transmitting an operational velocity to said portion (3) of the machine (1); determining (S104) a stability condition of the machine (1) based on the first sensor signal (4), the second sensor signal (5) and the command signal (6), and outputting (S105) a control signal (7) to control the operational component (2) as a function of the determined stability condition, wherein the stability condition is determined by monitoring and estimating both the static and the dynamic stability conditions of the machine (1), in particular by monitoring and estimating the position of the center of gravity and of an index of stability of the machine (1), relative to a contact area of the machine (1) with the ground (G).