Motor Grader Articulation Control for Unintended Movement Detection

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Solution Overview

Problem

Existing articulation control systems for motor grader machines fail to accurately detect unintended directional movements of articulated implements, leading to difficulties in maneuverability, potential collisions, and reduced speed due to misalignment between steering and articulation angles, and may miss temporary deviations or deviations below a predetermined threshold.

Innovation Solution

An articulation control device equipped with processors and memory that determines unintended directional movement by tracking instantaneous and accumulated movement values over a threshold quantity of time intervals, triggering a response action when the articulated implement moves in an unintended direction, thereby improving control and preventing misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a predetermined minimum angle of deviation threshold is used to detect articulation angle deviation, then false detections of temporary deviations are reduced, but deviations below the threshold or lasting less than the threshold period are not detected

Engineering Contradiction:

Improveaccuracy of unintended movement detectionVSAvoidcomplexity of detection logic

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system dynamically adjusts the detection threshold based on the counter value, which represents the duration of deviation. The threshold is not fixed but evolves with time, allowing the system to differentiate between temporary fluctuations and sustained unintended movements. This dynamic approach resolves the contradiction by making the detection criterion adaptive rather than static.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The counter is initialized to zero and incremented with each sampling period where deviation exceeds the threshold. This preliminary counting action allows the system to accumulate evidence of unintended movement before triggering a response, ensuring that temporary deviations are filtered out while sustained deviations are detected.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If the articulation control device responds immediately to detected deviations, then control accuracy is improved, but temporary deviations cause unnecessary control actions

Engineering Contradiction:

Improveprecision of articulation angle controlVSAvoidsmoothness of articulation control

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The system samples the articulation angle at periodic intervals (e.g., every 10 milliseconds) and uses a counter to track the number of consecutive periods where deviation occurs. This periodic sampling with counting allows the system to distinguish between transient and sustained deviations, triggering control actions only when the counter exceeds a threshold, thus avoiding unnecessary responses to temporary fluctuations.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

Before triggering a control response, the system performs preliminary counting of deviation periods through the counter mechanism. This preliminary action ensures that only sustained deviations (those exceeding the threshold number of periods) trigger control actions, filtering out temporary anomalies while maintaining precision for genuine unintended movements.

Inventive Principle:

Principle #10Preliminary action

3Speed

If the threshold quantity of time intervals is set low, then detection responsiveness is improved, but temporary deviations are falsely detected as unintended movements

Engineering Contradiction:

Improveresponsiveness of deviation detectionVSAvoidaccuracy of unintended movement detection

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The detection threshold is dynamic, based on the counter value that increments with each sampling period. Rather than using a fixed low threshold that causes false detections, the system adapts the threshold to the duration of deviation, allowing responsive detection of sustained unintended movements while filtering temporary fluctuations through the time-based counting mechanism.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11149408B2Detection of unintended directional movement of an articulated implement of a machine

Publication Date: 2021.10.19 CATERPILLAR INC

AI summary

A motor grader is disclosed. The motor grader may include an articulated implement. The motor grader may include an articulation control device. The articulation control device may be configured to determine that articulation motion of the articulated implement is occurring, for a threshold amount of time, in a second direction that is different from a first direction indicated by an articulation control command. The articulation control device may be configured to perform a response action based on determining that articulation motion of the articulated implement is occurring, for the threshold amount of time, in the second direction that is different from the first direction indicated by the articulation control command.