High-fidelity automatic player musical instrument, automatic player used therein and method employed therein
AssigneeYamaha Corporation
InventorTomoya Sasaki
Life of this patent
Estimating the term…
Abstract
An automatic player piano includes key sensors, solenoid-operated key actuators and a controller, which form a servo-control loop, and the key motion is reproduced under the control of the servo-control loop; the servo-control loop adjusts the driving pulse signal to a target duty ratio or mean current so as to force the black and white keys to travel on reference key trajectories; the controller categorizes the key motion in half-stroke or full-stroke, and determines the target duty ratio on the basis of a deviation between the target key position and the actual key position, a deviation between the target key velocity and the actual key velocity and the sort of key motion so as to make the key motion stable.
Claims20
An automatic player musical instrument for producing tones, comprising:
- an acoustic musical instrument including
- plural manipulators selectively moved for specifying the pitch of said tones, and
- a tone generator connected to said plural manipulators and responsive to motion of said plural manipulators for producing said tones at the specified pitch;
- and
- an automatic player including
- plural sensors for producing detecting signals representative of a physical quantity expressing said motion,
- plural actuators selectively energized with a driving signal so as to give rise to said motion of said plural manipulators, and
- a controller connected to said plural sensors and said plural actuators for forming a servo-control loop and forcing said plural manipulators to travel on reference trajectories with said driving signal, the magnitude of which contains a loop gain component representative of response characteristics of said servo-control loop and a fundamental component representative of a constant load to be exerted on said plural manipulators,
- said controller categorizing said motion in a first sort of motion in which said plural manipulators change the direction of motion through a reversal longer than a critical time period or a second sort of motion in which said plural manipulators change the direction of motion through said reversal equal to or shorter than said critical time period,
- said controller enlarging said fundamental component around said reversal in said second sort of motion so as to keep said motion stable.
An automatic player for a musical instrument having plural manipulators and a tone generator, comprising
- plural sensors for producing detecting signals representative of a physical quantity expressing motion of said plural manipulators,
- plural actuators selectively energized with a driving signal so as to give rise to said motion of said plural manipulators, and
- a controller connected to said plural sensors and said plural actuators for forming a servo-control loop and forcing said plural manipulators to travel on reference trajectories with said driving signal, the magnitude of which contains a loop gain component representative of response characteristics of said servo-control loop and a fundamental component representative of a constant load to be exerted on said plural manipulators,
- said controller categorizing said motion in a first sort of motion in which said plural manipulators change the direction of motion through a reversal longer than a critical time period or a second sort of motion in which said plural manipulators change the direction of motion through said reversal equal to or shorter than said critical time period,
- said controller enlarging said fundamental component around said reversal in said second sort of motion so as to keep said motion stable.
A method for controlling manipulators of a musical instrument through a servo-control loop, comprising the steps of:
- a) comparing a target value of physical quantity on a reference trajectory representative of motion of a manipulator to be realized with an actual value of said physical quantity on an actual trajectory along which said manipulator travels so that a deviation of said actual trajectory from said reference trajectory is determined through the comparison,
- b) adjusting a driving signal to a magnitude containing a first component determined on the basis of a loop gain representative of response characteristics of said servo-control loop for reducing said deviation and a second component having a relatively small value when said motion of said manipulator is categorized in a first sort of motion in which said manipulator changes the direction of said motion through a reversal longer than a critical time period,
- c) adjusting said driving signal to another magnitude containing said first component and said second component having a relatively large value when said motion of said manipulator is categorized in a second sort of motion in which said manipulator changes the direction of motion through said reversal equal to or shorter than said critical time period without executing said step c),
- d) supplying said driving signal to an actuator associated with said manipulator and forming a part of said servo-control loop so that said manipulator is further moved on said actual trajectory, and
- e) repeating said steps a) to d) until said manipulator reaches the end of said reference trajectory.
Dependencies are inferred from the claim text.