Automatic Piano Playing System Self-Calibration

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Solution Overview

Problem

Existing automatic playing systems for acoustic pianos struggle to reproduce music performances with high fidelity across different models, due to variations in component weights, structures, and sensor offset voltages, leading to inconsistent tone production.

Innovation Solution

An automatic playing system with a self-teaching function that adjusts control parameters based on sensor feedback to optimize tone production, using a computer program to determine the relation between music data codes and control data, allowing for tailored settings for individual pianos.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed set of control parameters is used for automatic playing, then the system can operate简单地, but it cannot adapt to different acoustic piano models, resulting in poor tone reproduction fidelity

Engineering Contradiction:

Improvetone reproduction fidelityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs self-teaching by automatically measuring the actual tone output of the specific acoustic piano it is connected to, and autonomously generates optimized control parameters tailored to that instrument's characteristics without requiring manual calibration or external intervention

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system dynamically adjusts control parameters such as key depression force, duration, and timing based on the measured characteristics of the specific acoustic piano model, allowing adaptation to variations in hammer weight, string tension, and action mechanism across different instruments

Inventive Principle:

Principle #35Parameter changes

2Reliability

If control parameters are manually adjusted for each piano model, then tone reproduction fidelity can be improved, but the setup time and operational complexity increase significantly

Engineering Contradiction:

Improvetone reproduction fidelityVSAvoidsetup time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system eliminates manual setup by automatically performing the calibration process through self-teaching, where it measures the piano's response to test inputs and generates optimized control parameters autonomously, reducing setup time from potentially hours of manual adjustment to minutes of automated measurement

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system performs preliminary measurements and characterizations of the acoustic piano during the self-teaching phase, storing the results as customized control parameters that are ready for immediate use in automatic playing, avoiding the need for adjustment during actual performance

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If standard control signals are sent to key actuators, then the automatic playing system can function universally, but it cannot account for individual piano variations, resulting in inconsistent tone production

Engineering Contradiction:

Improveadaptability to different piano modelsVSAvoidtone production consistency

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system customizes control parameters for each acoustic piano model by measuring its specific characteristics during self-teaching, adjusting parameters such as actuator force, key depression velocity, and holding time to compensate for variations in hammer weight, string configuration, and action mechanism across different instruments

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system uses feedback from tone sensors or microphones to measure the actual output of the acoustic piano in response to control signals, and iteratively adjusts the control parameters to optimize tone production consistency across different piano models

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

Enables high-fidelity music reproduction on various acoustic pianos by adapting control parameters to the specific characteristics of each instrument, ensuring accurate tone production and loudness control.

Implementation Method 1

each of the key actuators has a solenoid connected to the controller and a plunger projectable from and retractable into the solenoid

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS7435895B2Automatic playing system used for musical instruments and computer program used therein for self-teaching

Publication Date: 2008.10.14 YAMAHA CORP

AI summary

An automatic playing system is independent of acoustic pianos, and is designed to perform music tunes expressed by sets of MIDI music data codes on the acoustic pianos; since the acoustic pianos have their own individualities, control parameter table, which were prepared through experiments on a standard piano, are not optimum for most of the acoustic pianos due to the individualities: the automatic playing system can tailor the control parameter tables defining relation between the magnitude of driving signal and the MIDI velocity and relation between the magnitude of driving signal and time lag from the supply of the driving signal and the collision between the hammers and the strings for each sort of acoustic pianos before the automatic playing so that the automatic playing system reproduces the music tunes at high fidelity regardless of the sort of acoustic pianos.