Motor Control Device for Vehicle Slide Doors

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Solution Overview

Problem

Existing motor control devices for slide doors on vehicles, which use tilt sensors to detect sloping ground, face increased circuit complexity and delayed response due to additional signal processing, leading to inefficient control of electric motors.

Innovation Solution

A motor control device that utilizes a rotation sensor and position detector to control the electric motor's direction and current supply, allowing regenerative braking without a tilt sensor, thereby stopping the slide door by rotating in the opposite direction of gravity's influence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tilt sensor is added to detect sloping ground, then the ability to detect and respond to sloping ground is improved, but the circuit complexity and processing time increase

Engineering Contradiction:

Improveability to detect sloping groundVSAvoidcircuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the tilt sensor from the system and extracts only the necessary detection function. Instead of adding a separate sensor, the system uses the existing rotation sensor to detect motor rotation direction, which indirectly indicates sloping ground conditions. This eliminates the additional circuit complexity while maintaining the core detection capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The rotation sensor is made multi-functional by using it for both its primary function (detecting motor rotation during normal operation) and the secondary function of detecting sloping ground. When no current is supplied to the motor, any detected rotation is attributed to gravity on sloping ground rather than motor operation. This eliminates the need for a dedicated tilt sensor.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a tilt sensor is added to detect sloping ground, then the ability to detect and respond to sloping ground is improved, but the response time is delayed due to additional processing

Engineering Contradiction:

Improveability to detect sloping groundVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent merges the sloping ground detection function with the existing motor control processing. The same control unit that manages motor operation also processes rotation sensor signals to detect sloping ground. By combining these functions in a single processing pipeline, the system eliminates the additional processing time that would result from a separate tilt sensor and its dedicated processing path.

Inventive Principle:

Principle #5Merging (Combining)

3Use of energy by moving object

If regenerative braking is used to stop the slide door, then energy efficiency is improved, but control precision may be reduced

Engineering Contradiction:

Improveenergy efficiencyVSAvoidcontrol precision

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent implements feedback control by continuously monitoring the rotation sensor signals during regenerative braking. The control unit adjusts the braking force in real-time based on the detected rotation direction and magnitude, ensuring the slide door stops at the precise desired position. This feedback mechanism maintains control precision while utilizing energy-efficient regenerative braking.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control unit applies regenerative braking in periodic pulses rather than continuous force, allowing for precise control of the stopping process. By intermittently applying and releasing braking force based on real-time rotation detection, the system achieves both energy efficiency and precise stopping control.

Inventive Principle:

Principle #19Periodic action

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

This solution enables efficient stopping of slide doors on sloping ground without a tilt sensor, reducing circuit complexity and response time, and effectively managing movement due to gravity.

Implementation Method 1

the control unit stops the slide door by rotating and driving the electric motor in an opposite direction to a moving direction due to gravity

Methodology Applied

Scientific EffectRegenerative braking: Electromagnetic Induction

Implementation Method 2

a position detector configured to detect a rotation direction of the electric motor when a detection signal is input from a rotation sensor, which detects the rotation of the electric motor

Methodology Applied

Scientific EffectRotation detection:

Data Source

PatentUS10122303B2Motor control device

Publication Date: 2018.11.06 MITSUBA CORP

AI summary

The motor control device is an electric motor control device including a control unit (control circuit unit) configured to output a forward-rotation command or a reverse-rotation command to the electric motor. The control unit includes a position detector (door opening/closing information generation circuit) configured to detect a rotation direction of the electric motor when a detection signal is input from a rotation sensor (Hall integrated circuit (IC)), which detects the rotation of the electric motor, while no current is supplied to the electric motor. The control unit includes an electric current supply device (pulse width modulation (PWM) command generation circuit) configured to supply an electric current by which the electric motor is rotated in an opposite direction to the detected rotation direction by increasing an electric current supply duty ratio every time the detection signal is switched.