RFID Safety Field for Compactor Operator Monitoring

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Solution Overview

Problem

Existing safety systems for multipurpose compactors, such as those using infrared or ultrasonic sensors, are prone to interference and have limited directional coverage, making them inadequate for ensuring safe operation on construction sites.

Innovation Solution

A safety system utilizing RFID technology with low-frequency electromagnetic waves, providing a spherical protective field that allows for wide-ranging, direction-independent monitoring of the operator's distance from the compactor, and automatically initiating safety measures if the minimum distance is not maintained, such as a drive stop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If infrared or ultrasonic sensors are used for safety monitoring, then distance measurement capability is provided, but the system becomes interference-prone and has limited directional coverage

Engineering Contradiction:

Improvesafety monitoring reliabilityVSAvoidinterference susceptibility

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces optical/mechanical sensing systems (infrared or ultrasonic sensors) with an electromagnetic field-based RFID safety system. The transmitter generates a spherical electromagnetic protective field that passively detects the presence of the operator without being susceptible to interference from dirt, reflections, or environmental factors that plague sensor-based systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a spherical electromagnetic protective field generated by the transmitter, which provides 360-degree omnidirectional coverage around the compactor. This spherical field geometry eliminates the directional limitations of linear sensor arrays and ensures comprehensive monitoring of the operator's position from all angles.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Reliability

If infrared or ultrasonic sensors are used for safety monitoring, then distance measurement is enabled, but the coverage area is limited due to directional characteristics

Engineering Contradiction:

Improvesafety monitoring reliabilityVSAvoidmonitoring coverage area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The electromagnetic protective field serves multiple functions simultaneously: it defines the safety zone boundary, detects operator presence regardless of position or orientation, and provides continuous monitoring without requiring multiple discrete sensors positioned at different locations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If emergency stop levers are provided at the front and rear, then emergency stop functionality is achieved, but the system cannot prevent accidental stopping when the operator is within the safety zone

Engineering Contradiction:

Improveemergency stop reliabilityVSAvoidoperational continuity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements continuous feedback through the electromagnetic protective field that actively monitors operator presence within the safety zone. The system provides real-time information about whether the operator is inside or outside the protected area, enabling intelligent differentiation between intentional emergency stops and normal operation within the safety zone.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies different operational rules to different spatial zones: the electromagnetic protective field creates a defined local safety zone around the compactor where normal operation is permitted, while areas beyond this zone trigger emergency stop conditions. This spatial differentiation allows the operator to work safely within the zone without causing unnecessary halts.

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 ensures safe operation by providing effective protection of the operator from the compactor, reducing the risk of interference and unnecessary halting, and allowing the machine to move away from the operator even if they are within the protective field, while preventing the machine from stopping if approached from the rear.

Implementation Method 1

the safety system according to the invention works with electromagnetic waves in the LF-range (low-frequency), i.e. within a range of 30 to 300 kHz

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

The transmitter and the receiver make it possible to monitor whether the movable unit maintains a minimum distance to the multipurpose compactor

Methodology Applied

Scientific EffectElectromagnetic wave detection: Electromagnetic Induction

Data Source

PatentUS8672582B2Multipurpose compactor and method for operating the multipurpose compactor

Publication Date: 2014.03.18 BOMAG GMBH

AI summary

A multipurpose compactor with an automatic safety system is provided. The automatic safety system comprises at least one transmitter and one receiver. The transmitter is coupled mechanically fixed to the multipurpose compactor and/or to a unit movable relative to the multipurpose compactor. The receiver is coupled fixedly to the movable unit and/or the multipurpose compactor.