Vehicle Door Braking Circuit Using Generator Voltage Detection

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Solution Overview

Problem

Existing door systems for vehicles, particularly public transport vehicles, face challenges in ensuring safe manual adjustment of electrically driven door leaves, as current braking solutions either fail to brake adequately at high speeds or brake too hard at low speeds, and may cause damage or excessive effort during manual operation.

Innovation Solution

A door system with a braking circuit that detects the generator voltage produced by the electric motor during manual adjustment, switching on an electrical load only when the voltage exceeds a certain range to create a braking effect, thereby preventing excessive speed and minimizing effort during manual operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a speed-independent brake is used for manual door leaf adjustment, then the door leaf can be braked during manual operation, but the brake will either brake too hard at low adjustment speeds or not brake hard enough at high adjustment speeds

Engineering Contradiction:
Improvebraking effectivenessVSAvoidmanual adjustment effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The brake circuit is designed to dynamically adjust the braking effect based on the generator voltage detected from the electric motor. When the detected generator voltage exceeds a threshold value (indicating high manual adjustment speed), the brake circuit activates the electrical load to provide braking. When the voltage is below the threshold (low speed), the brake circuit remains inactive, allowing smooth manual operation without excessive braking force.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If a brake circuit is activated during manual door leaf adjustment, then excessive speed can be prevented, but the brake may cause damage or excessive effort during manual operation at low speeds

Engineering Contradiction:
Improveexcessive speed damageVSAvoidmanual adjustment effort
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The brake circuit monitors the generator voltage parameter produced by the electric motor during manual adjustment and uses this parameter to control the braking action. By comparing the detected generator voltage against a predetermined threshold, the system intelligently activates or deactivates the electrical load to provide appropriate braking force only when necessary, avoiding interference with normal manual operation.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the electrical load is switched on continuously to prevent excessive speed, then high-speed damage is prevented, but the door leaf cannot be adjusted manually with minimal effort

Engineering Contradiction:
Improveprotection from damageVSAvoidmanual adjustment effort
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The brake circuit implements a feedback mechanism by continuously detecting the generator voltage generated by the electric motor during manual door leaf adjustment. This detected voltage serves as feedback about the current adjustment speed, allowing the brake circuit to make real-time decisions about whether to activate the electrical load for braking, thus protecting against excessive speed while minimizing interference during normal operation.

Inventive Principle:
Principle #23Feedback

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 brakes the door leaf at high manual adjustment speeds to prevent damage while allowing smooth operation at low speeds, ensuring safe and effortless manual adjustment by controlling the braking effect based on the generator voltage.

Implementation Method 1

when the door leaf is adjusted manually without controlling the door leaf's electric motor, the electric motor is in generator mode. The voltage generated by the electric motor is a function of the speed at which the door leaf is adjusted.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4002677B1Door system for a vehicle with a door leaf and method for selectively braking an electrically driven door leaf
Publication Date: 2024.08.14 BODE - DIE TUR GMBH
  • EP4002677B1 patent drawingFigure 1
  • EP4002677B1 patent drawingFigure 2

AI summary

The invention relates to a door system for a vehicle (1), wherein the door system comprises a door leaf (2), an electric motor (6) for driving the door leaf (2), and a brake circuit (7) with an electrical load (12) for braking the door leaf (2). The brake circuit (7) is configured to detect a generator voltage produced by the electric motor (6) in generator mode during manual adjustment of the door leaf (2) and is further configured to switch on the electrical load (12) when the detected generator voltage is in an overspeed range (21) and otherwise to switch off the electrical load (12). The invention also relates to a corresponding method for selectively braking an electrically driven door leaf (2).