Forklift Remote Control Range Limiting by Radio Signal Intensity

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Solution Overview

Problem

Existing industrial vehicle remote control systems face errors in traveling control due to excessive distance between the operator and the vehicle, leading to unclear visibility and potential safety hazards.

Innovation Solution

An industrial vehicle remote control system that uses a combination of wireless communication and antenna configuration to determine the position of the forklift based on received radio wave intensity, permitting or prohibiting remote control within specific ranges to ensure safe operation within visible distances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wireless communication range is extended to allow remote control from farther positions, then operator flexibility and remote control capability are improved, but visibility and control accuracy deteriorate leading to operational errors

Engineering Contradiction:
Improveremote control capabilityVSAvoidcontrol accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adjusts the remote control mode based on real-time distance measurements. When the operator is within the appropriate region, full remote control functions are enabled. When the operator moves beyond this region, the system automatically switches to a limited mode that restricts traveling control functions. This dynamic adaptation resolves the contradiction by allowing extended wireless communication range while maintaining control accuracy through context-aware function restriction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of remote control based on the operator's distance from the industrial vehicle. By measuring the distance and comparing it against a predetermined threshold, the system adjusts the level of remote control permission - enabling full control within the threshold distance and limiting control functions beyond it. This parameter-based adaptation allows the system to leverage extended wireless range while preventing operational errors through distance-dependent control restriction.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If remote control is permitted from excessively far positions, then operator safety from physical danger is improved, but control precision and visibility deteriorate

Engineering Contradiction:
Improveoperator safetyVSAvoidposition awareness
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The system implements dynamic mode switching that adapts to the operator's position. When the operator is far from the vehicle, the system transitions to a limited remote control mode that restricts traveling functions while maintaining material handling capabilities. This dynamic response allows operators to safely control material handling from distant positions while preventing imprecise traveling control when visibility is poor.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system applies different control permission qualities to different operational contexts. Material handling control is permitted with relaxed distance restrictions, while traveling control is subject to stricter distance limitations. This localized quality differentiation allows operators to safely perform material handling operations from farther positions while maintaining precise control over traveling only when within appropriate visual range.

Inventive Principle:
Principle #3Local quality

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 limits remote control to permissible ranges, reducing operational errors and enhancing safety by preventing remote control when the forklift is beyond visible distances, thus stabilizing communication conditions and improving safety.

Implementation Method 1

a possibility determination portion (36) that performs possibility determination based on the identification result, in which the forklift (20) is determined to be in the permission range (A1) when a state in which the received radio wave intensity (RS) is greater than or equal to the threshold intensity (RSth) continues for a first determination period (T1), and in which the forklift (20) is determined to be in the prohibition range (A2) when a state in which the received radio wave intensity (RS) is less than the threshold intensity (RSth) continues for a second determination period (T2)

Methodology Applied
Scientific EffectRadio wave intensity: Electromagnetic Induction

Data Source

PatentEP3578501B1Remote control system for industrial vehicles and remote control method for industrial vehicles
Publication Date: 2024.01.03 TOYOTA INDUSTRIES CORP
  • EP3578501B1 patent drawingFigure 1~2
  • EP3578501B1 patent drawingFigure 3
  • EP3578501B1 patent drawingFigure 4~6

AI summary

An industrial vehicle remote control system includes a forklift that has a vehicle communication unit and a remote control device that has a remote communication unit and is used to remotely control the forklift. A vehicle wireless CPU of the industrial vehicle remote control system acquires the received radio wave intensity of a remote control signal by which the two communication units wirelessly communicate, and, on the basis of the results thereof, determines whether the forklift is positioned in a permission range or in a prohibition range.