Haulage Vehicle Speed Control for Route Deviation Uncertainty

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Solution Overview

Problem

Existing haulage vehicle position calculating systems contain errors, leading to inaccurate calculations of positional departure from target routes, resulting in inadequate target vehicle speed settings.

Innovation Solution

The system calculates a target vehicle speed based on the maximum deviation amount from the target route, adjusting speed according to error probabilities and thresholds, using a position calculating system with GPS and error ellipses to determine suitable travel control for haulage vehicles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the target vehicle speed is set high to maintain productivity, then productivity is improved, but the ability to correct positional deviation from the target route deteriorates

Engineering Contradiction:
Improvevehicle speedVSAvoidpositional accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies dynamics by making the target vehicle speed variable rather than constant. The control device dynamically adjusts the target vehicle speed based on the calculated positional deviation amount from the target route. When positional deviation is large, the target vehicle speed is reduced to allow for correction; when positional deviation is small, the target vehicle speed can be increased to maintain productivity. This dynamic adjustment resolves the contradiction between maintaining high speed for productivity and reducing speed for positional accuracy.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the target vehicle speed is set low to correct positional deviation, then positional accuracy is improved, but productivity deteriorates

Engineering Contradiction:
Improvepositional accuracyVSAvoidvehicle speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adjusts vehicle speed based on real-time positional deviation measurements. Instead of maintaining a constantly low speed, the vehicle operates at high speeds when on course (maintaining productivity) and only reduces speed when positional deviation exceeds thresholds (maintaining positional accuracy). This dynamic approach resolves the contradiction by making speed adjustment conditional rather than constant.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of vehicle speed based on the parameter of positional deviation. By establishing threshold values for positional deviation and corresponding target vehicle speeds, the system automatically adjusts speed parameters in response to position parameters. This parameter-based control resolves the contradiction between speed and accuracy by linking them through deviation thresholds.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the positional error is not considered in speed calculation, then the control system complexity is reduced, but the accuracy of positional departure calculation deteriorates

Engineering Contradiction:
Improvecontrol systemVSAvoidpositional departure accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements feedback by using the calculated positional deviation amount (which incorporates position error considerations) to adjust the target vehicle speed. The system continuously monitors position, calculates deviation from the target route, and feeds this information back to the speed control mechanism. This feedback loop ensures accurate positional departure calculation is maintained while keeping the control system relatively simple through automated threshold-based adjustments.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3190473B1Conveying vehicle and drive control device for same
Publication Date: 2021.01.27 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3190473B1 patent drawingFigure 1
  • EP3190473B1 patent drawingFigure 2A~2B
  • EP3190473B1 patent drawingFigure 3

AI summary

A haulage vehicle comprises: a position calculating system (220) calculating an estimated position of its own vehicle; a position range calculating unit (201b) calculating a position range which is centered around the estimated position and in which the haulage vehicle is present with a predetermined expected probability; a maximum deviation amount calculating unit (602) calculating a maximum deviation amount indicating a highest value among the amounts of deviations between a target route of the haulage vehicle and each of points included in the position range; a target vehicle-speed decision unit (603) setting a target vehicle speed of the haulage vehicle to be relatively low when the maximum deviation amount is relatively large; and a target route-tracing unit (201g) performing control for the haulage vehicle to travel along the target route in compliance with the target vehicle speed.