Electric Fader Drive Control for Silent and Accurate Positioning

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Solution Overview

Problem

Conventional electric fader drive units generate noise during operation, which is problematic in quiet environments like studios, and struggle to balance speed and accuracy in reaching target positions due to individual differences and changes over time.

Innovation Solution

The electric fader drive unit employs a dual-mode operation system, switching between high-speed and silent modes based on the distance to the target position, using precharge and postcharge drive signals to minimize noise and ensure accurate positioning, incorporating a CPU for control and a feedback loop for servo control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the electric fader is driven with low drive power to achieve smooth and accurate stopping at target position, then the stopping accuracy is improved, but the fader may not reach the target position due to insufficient drive power and individual differences

Engineering Contradiction:
Improvestopping accuracyVSAvoidreachability of target position
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies dynamic drive power adjustment by switching between two drive power levels (first drive power and second drive power) based on the fader's position relative to the target. The control unit dynamically selects higher drive power when the fader is far from target and lower drive power when close to target, resolving the contradiction between reaching the target reliably and stopping accurately.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the electric fader is driven with high drive power to prevent influence of individual difference and changes over years, then the reliability is improved, but the fader may stop at a position beyond the target position (overshoot)

Engineering Contradiction:
Improveconsistency of operationVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The control unit dynamically adjusts drive power based on real-time position feedback. When the fader is far from the target position, high drive power is applied to overcome individual differences and ensure reliable movement. When the fader approaches the target position, drive power is reduced to prevent overshoot, thus maintaining both reliability and positioning accuracy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the control unit continuously monitors the fader's position and adjusts drive power accordingly. This closed-loop control ensures that the fader reaches the target position accurately by reducing drive power when approaching the target, preventing overshoot while maintaining reliable operation throughout the travel range.

Inventive Principle:
Principle #23Feedback

3Productivity

If the movement speed of the electric fader is increased to improve productivity, then the operation speed is improved, but the generated noise becomes larger

Engineering Contradiction:
Improvemovement speedVSAvoidoperation noise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent employs periodic action by using two distinct drive modes (first drive and second drive) with different speed and noise characteristics. The system switches between these modes based on the fader's position, achieving high-speed operation for most of the travel distance while using low-noise operation near the target position, thus balancing productivity and noise reduction.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3128689B1Electric fader drive unit, audio mixer, and electric fader driving method
Publication Date: 2021.10.27 YAMAHA CORP
  • EP3128689B1 patent drawingFigure 1
  • EP3128689B1 patent drawingFigure 2
  • EP3128689B1 patent drawingFigure 3A~3B

AI summary

An electric fader drive unit includes a drive portion, a fader position control portion, and an electric fader control portion. The fader position control portion detects a distance between a current position of the electric fader and a target position, indicates a high speed movement mode when the distance is not less than a predetermined value, and indicates a silent movement mode when the distance is less than the predetermined value. The electric fader control portion controls the drive portion to change the drive power to silent drive power not less than the minimum drive power that is the lowest drive power for moving the electric fader when the fader position control portion indicates the silent movement mode, and controls the drive portion to change the drive power to base drive power more than the silent drive power when the fader position control position indicates the high speed movement mode.