System and method for actuating keys with different lever advantages
View Patent ↗The keys in a reproducing piano are actuated by a plurality of solenoids, one for each key to be played. The solenoids are arranged along the width of the keyboard and deviated from each other in the front-back direction of the keys in a staggered manner. A consequence of this arrangement is that the mechanical lever advantage of some solenoids is greater than the mechanical lever advantage of others, and as a result, some keys are played more loudly than others. In order to correct this problem, the drive applied to a solenoid is adjusted to compensate for the mechanical lever advantage, thereby allowing a performance to be accurately reproduced.
1. A method for driving an actuator in an instrument, comprising:
receiving drive information, the drive information comprising actuator information identifying an actuator and normalized drive information specifying a normalized drive;
determining a lever-adjusted drive based on the actuator information and the normalized drive information; and
applying the lever-adjusted drive to the identified actuator.
2. The method of claim 1 , wherein the lever-adjusted drive is determined based on a lever scaling factor.
3. The method of claim 2 , wherein the lever-adjusted drive is determined by multiplying the normalized drive by the lever scaling factor.
4. The method of claim 2 , further comprising identifying a lever advantage set based on the actuator information.
5. The method of claim 4 , further comprising identifying the lever scaling factor based on the lever advantage set.
6. The method of claim 4 , wherein the lever scaling factor has been determined by testing the loudness of a plurality of keys associated with the lever advantage set.
7. The method of claim 4 , wherein the lever scaling factor is calculated by dividing a first loudness associated with a default lever advantage set by a second loudness associated with the lever advantage set.
8. The method of claim 1 , wherein the lever-adjusted drive is determined by consulting a lookup table.
9. The method of claim 8 , wherein the normalized drive is used an address of the lookup table.
10. The method of claim 8 , further comprising:
selecting the lookup table from a plurality of lookup tables based on the actuator information.
11. A system for driving an actuator in an instrument, comprising:
means for receiving drive information, the drive information comprising actuator information identifying an actuator and normalized drive information specifying a normalized drive;
means for determining a lever-adjusted drive based on the actuator information and the normalized drive information; and
means for applying the lever-adjusted drive to the identified actuator.
12. The system of claim 11 , wherein the lever-adjusted drive is determined based on a lever scaling factor.
13. The system of claim 12 , wherein the lever-adjusted drive is determined by multiplying the normalized drive by the lever scaling factor.
14. The system of claim 12 , further comprising means for identifying a lever advantage set based on the actuator information.
15. The system of claim 14 , further comprising means for identifying the lever scaling factor based on the lever advantage set.
16. The system of claim 14 , wherein the lever scaling factor has been determined by testing the loudness of a plurality of keys associated with the lever advantage set.
17. The system of claim 14 , wherein the lever scaling factor is calculated by dividing a first loudness associated with a default lever advantage set by a second loudness associated with the lever advantage set.
18. The system of claim 11 , wherein the lever-adjusted drive is determined by consulting a lookup table.
19. The system of claim 18 , wherein the normalized drive is used an address of the lookup table.
20. The system of claim 18 , further comprising:
means for selecting the lookup table from a plurality of lookup tables based on the actuator information.
21. A computer-readable medium encoded with instructions executable to perform a method comprising:
receiving drive information, the drive information comprising actuator information identifying an actuator and normalized drive information specifying a normalized drive;
determining a lever-adjusted drive based on the actuator information and the normalized drive information; and
applying the lever-adjusted drive to the identified actuator.
22. The computer-readable medium of claim 21 , wherein the lever-adjusted drive is determined based on a lever scaling factor.
23. The computer-readable medium of claim 22 , wherein the lever-adjusted drive is determined by multiplying the normalized drive by the lever scaling factor.
24. The computer-readable medium of claim 22 , further comprising identifying a lever advantage set based on the actuator information.
25. The computer-readable medium of claim 24 , further comprising identifying the lever scaling factor based on the lever advantage set.
26. The computer-readable medium of claim 24 , wherein the lever scaling factor has been determined by testing the loudness of a plurality of keys associated with the lever advantage set.
27. The computer-readable medium of claim 24 , wherein the lever scaling factor is calculated by dividing a first loudness associated with a default lever advantage set by a second loudness associated with the lever advantage set.
28. The computer-readable medium of claim 21 , wherein the lever-adjusted drive is determined by consulting a lookup table.
29. The computer-readable medium of claim 28 , wherein the normalized drive is used an address of the lookup table.
30. The computer-readable medium of claim 28 , further comprising:
selecting the lookup table from a plurality of lookup tables based on the actuator information.