Electric Trolley Safety Control Without Heavy Motor Interruption Circuits

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Solution Overview

Problem

Existing electric trolleys face challenges in stopping travel reliably due to the size and weight of interruption circuits required to halt the electromotor, which compromises safety and efficiency.

Innovation Solution

The electric trolley incorporates a safety controller and driving commander that manage operation and control signals to independently stop the motor driver, utilizing an operation blocker and control blocker within a low voltage power supply system to prevent motor operation, thereby reducing the need for large and heavy interruption circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an interruption circuit is used to stop the electromotor by interrupting power supply, then the motor can be stopped reliably, but the circuit becomes large and heavy

Engineering Contradiction:

Improvestopping reliabilityVSAvoidinterruption circuit weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces the traditional mechanical/electrical interruption circuit with a control signal-based stopping mechanism. The safety controller sends a stop command through the existing control architecture (blocking operation permission signals or sending stop commands to the motor driver), eliminating the need for heavy power supply interruption circuits while achieving reliable motor stopping.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a large interruption circuit is installed to ensure safe stopping, then stopping reliability improves, but the device size and weight increase

Engineering Contradiction:

ImprovesafetyVSAvoidcircuit area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The invention substitutes physical interruption circuitry with software/control signal-based stopping. The safety controller utilizes the existing control architecture to block operation permission signals or send stop commands to the motor driver, achieving safe stopping without requiring additional large-area interruption circuits.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the power supply circuit is interrupted to stop the motor, then driving can be stopped, but the response time increases due to circuit complexity

Engineering Contradiction:

Improvestop functionVSAvoidstopping time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system maintains readiness to stop by continuously monitoring safety conditions and having the safety controller prepared to block operation permission signals or send stop commands instantaneously. This preliminary preparation eliminates the time delay associated with activating interruption circuits, as the stopping capability is already in place and can be activated immediately when needed.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11932119B2Electric trolley

Publication Date: 2024.03.19 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

Electric trolley includes safety controller that determines whether or not to stop the driving of driving wheel, and driving commander that outputs, to the motor driver, (i) an operation permission signal for permitting motor to be operated and (ii) a control signal for controlling an operation of motor, in which safety controller performs control to stop inputs of the operation permission signal and the control signal to motor driver when the safety controller determines to stop the driving of driving wheel.