(19)
(11) EP 4 468 286 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
27.11.2024 Bulletin 2024/48

(21) Application number: 23216390.7

(22) Date of filing: 13.12.2023
(51) International Patent Classification (IPC): 
G10B 3/10(2006.01)
G10B 1/04(2006.01)
G10B 3/22(2006.01)
(52) Cooperative Patent Classification (CPC):
G10B 3/10; G10B 1/04
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA
Designated Validation States:
KH MA MD TN

(30) Priority: 26.04.2023 PL 44462323

(71) Applicant: Politechnika Slaska
44-100 Gliwice (PL)

(72) Inventors:
  • KOWOL, Pawel
    44-102 Gliwice (PL)
  • NOWAK, Pawel
    41-940 Piekary Slaskie (PL)

   


(54) MECHATRONIC ACTION FOR A PIPE ORGAN AND CONTROL STRATEGY FOR THE POWER SUPPLY OF THE VCM IN A MECHATRONIC ACTION FOR A PIPE ORGAN


(57) A mechatronic action for a pipe organ, characterised in that, for one tone - one key (12) of the keyboard - it consists of a VCM (9) connected by a linkage (10) to a pallet (8) of the valve of the pipe (7) or pipes in the case of a multi-voice organ, a key displacement sensor (11) and a microprocessor system (13) which, on the basis of the signal from the key displacement sensor (11), controls the power supply to the VCM (9). The subject of the invention is also method of controlling the power supply of the VCM in the mechatronic action of a pipe organ




Description


[0001] The object of the invention is a mechatronic action for a pipe organ and a method for controlling the power supply to a voice coil motor (VCM) in a mechatronic action for a pipe organ in which a VCM is used.

[0002] In a pipe organ, sound is produced by the flow of air through the pipe (1). This flow is regulated by a valve in which the moving element is a pallet (3). The pallet, together with the return spring (2), is located in the windchest (4), where there is increased air pressure generated by the pneumatic supply system (usually a blower with bellows). The control element of the valve is the key (6) and the system that transmits the control signal from the key to the pallet is the action (5). The most common types of actuator are mechanical (tracker), pneumatic, and electric. Mechanical action is a system of mechanical connections using linkages, levers and rollers. Pneumatic action uses a system of compressed air to transmit the signal from the key to the pallet. Electric action uses an electromagnetic actuator (usually an electromagnet) to create the movement of the pallet, which is activated by a switch (usually an electrical contact system) attached to the key. Mechanical and electric action are currently the most commonly used in organ building. Mechanical action allows full control over the dynamics of sound generation (the speed at which the pallet opens and closes), with the limitation that the playing table (keyboard) must be placed very close to the instrument. Electric action allows the keyboard to be moved away from the instrument, but does not offer control over the dynamics of the sound produced by the organ. The system that moves the valve pallet (electromagnet) works in two modes: either it is off - the key is closed - or it is on and the key is open. The speed at which the pallet opens is determined and limited by the dynamics of the electromagnet.

[0003] A method of controlling an electric action is known from the description of the invention PL174978, in which the velocity of the key press (articulation) is a control signal from a dynamic keyboard and is processed by a fuzzy logic that controls an electromagnetic actuator (electromagnet) that opens the valve of the pipe.

[0004] Action systems using servomechanisms (an electromagnetic actuator operating in a feedback loop from the position signal of the actuator's moving element) as actuators - moving the pallets - are described in the literature (C. E Pykett, 'Pipe organs: physics in an action', Phys. World 15 (12) 21, 2002).

[0005] From the description of the invention of the US patent 8,198,521, 2012, it is known that the pipe organ drive systems - electromagnets - are proportionally controlled to achieve any pallet opening. A mechatronic action is known (T K

dzio

ka, S Kowalski, T Mońko, "Pipe organ evolution. From mechanical to mechatronic subsystems", Journal of Engineering, Energy and Informatics 1/2021 (1), 29-42), where the actuator moving the pallet is a stepper motor.

[0006] The use of VCM in musical instruments is well known (R. Oboe, 'A multi-instrument, force-feedback keyboard', Computer Music Journal, vol. 30, no. 3, pp. 38-52, 2006) in dynamic keyboard systems that mimic the natural behaviour of a keyboard instrument.

[0007] The aim of the invention is to develop such a mechatronic action, which will have the characteristics of mechanical action - the ability to fully control the dynamics of sound generation, i.e. to control the speed of opening and closing of the pallet, and, as in the case of electric action, to allow the playing table to be moved away from the instrument.

[0008] The essence of the invention is a mechatronic action for a pipe organ, characterised in that, for one note - one key (12) of the keyboard - it consists of a VCM (9) connected by a linkage (10) to the pallet (8) of the pipe valve (7) or pipes in the case of a multi-voice organ, a key displacement sensor (11) and a microprocessor system (13) which, on the basis of the signal from the key displacement sensor (11), controls the power supply to the VCM (9).

[0009] The essence of the invention is also a method of controlling the power supply of the VCM in the mechatronic action of a pipe organ, consisting in the fact that the microprocessor system, on the basis of the signal from the key displacement sensor, which is information about the key displacement, determines the value of the power supply of the VCM motor according to the formula:

where: y is the VCM supply value (voltage or PWM signal) expressed as a percentage of the maximum supply value, x is the key displacement value measured by the key displacement sensor and expressed as a percentage of the maximum key displacement value, k1 is a signal gain constant determined during control system tuning, MIN is the VCM supply value determined by measurements and read from the pallet opening curve, corresponding in the pallet opening process to the maximum VCM supply value for a closed pallet or in the pallet closing process to the maximum VCM supply value for a closed pallet, MAX is the VCM supply value measured and read from the pallet opening curve, corresponding in the pallet opening process to the maximum VCM supply value for a closed pallet, corresponding in the pallet opening process to the minimum VCM supply value for a fully open pallet or in the pallet closing process to the minimum VCM supply value for a fully open pallet, the change in the MIN and MAX values for changes in the pallet opening and closing process taking place after the key displacement equal to or greater than 75% of the maximum key displacement and after the time corresponding to the pallet opening at 50% of full opening determined from the waveform of the pallet opening at the step forcing of the VCM supply and counted from the moment of the start of the pallet opening process.

[0010] The invention is visualised in the drawing in which Fig. 1 shows the sound generation system in a pipe organ, Fig. 2 the mechatronic action, Fig. 3 curves of the pallet opening versus the VCM supply, Fig. 4 the waveform of the opening of the pallet as a result of the stepping of the VCM supply.

Example.



[0011] Thanks to its design and the way in which the VCM supply is controlled, the mechatronic action makes it possible to fully control the dynamics of sound generation, i.e., the pipe valve pallets open in accordance with the keys being moved - pressed by the organist.

[0012] The object of the invention is a mechatronic action device used in a pipe organ, consisting of (for one sound - one key (12) of the keyboard): a VCM (9) connected by a linkage (10) to a pallet (8) of a pipe valve (7) or pipes in the case of a multi-voice organ, a key displacement sensor (11), and a microprocessor system (13) which, on the basis of the signal from the key displacement sensor (11), controls the power supply to the VCM (9).

[0013] The control of the VCM feed is based on parameters determined by measurement: the pallet opening and closing curve as a function of the VCM supply moving pallet (Fig. 3) and the dynamic pallet opening curve as a result of the VCM supply step (Fig. 4).

[0014] In the process of opening the pallet, there is a limit - a maximum - value A of the VCM supply at which the pallet remains closed - where the supply value is the voltage or PWM signal expressed as a percentage of the maximum supply value. Increasing the supply value above the A value triggers the pallet opening process - the VCM connected to the pallet by a linkage starts to move the pallet. When the VCM supply exceeds the A value, the pallet opening (K) is rapidly increased - the pallet falls. This effect is due to the fact that as long as the pallet is closed, the air pressure in the winch presses against the pallet. To open the pallet, the actuator must apply a force greater than the force generated by the return spring and the force generated by the air pressure in the winch. When the pallet is opened, even slightly, a stream of air begins to flow into the pipe. The air pressure on both sides of the pallet is equalised and the force of the air pressing on the pallet disappears. The force produced by the actuator then causes the pallet to jump (fall). The same phenomenon is experienced by the organist in the case of a mechanical action such as a key pluck (German: Druckpunkt). As the VCM supply continues to increase, the pallet opens further and further until it opens completely, which occurs at the B value of the VCM supply. Further increases in VCM supply will not change the pallet opening.

[0015] The pallet closing process follows the earlier pallet opening and begins when the VCM motor supply drops below H, the minimum VCM supply at which the pallet remains fully open. As the VCM supply continues to decrease, the pallet will open less and less until the VCM supply reaches G, which is the maximum VCM supply for a closed pallet during the pallet closing process.

[0016] The dynamic waveform of the pallet opening when the VCM is stepped makes it possible to determine the time ΔT required for the pallet to open halfway, which corresponds to the pallet dropping during normal pallet opening.

[0017] The power supply control of VCM in mechatronic action is based on the principle:

Where:
y-
value of the VCM supply expressed as a percentage of the maximum supply value,
x-
the key displacement, which is measured by the key displacement sensor and is expressed as a percentage of the maximum key displacement value,
k1 -
signal gain constant determined during control system tuning,
MIN -
value of the VCM supply corresponding, in the pallet opening process, to the maximum value of the VCM supply for a closed pallet (A) or, in the pallet closing process, to the maximum value of the VCM supply for a closed pallet (G),
MAX -
value of the VCM supply corresponding to the process of opening the pallet, to the minimum value of the VCM supply for a fully open pallet (B) or, in the process of closing the pallet, to the minimum value of the VCM supply for a fully open pallet (H) The change in the MIN and MAX values for the changes in the pallet opening and closing processes occurs after a key displacement equal to or greater than 75% of the maximum key displacement and after a ΔT time corresponding to the pallet opening at 50% of the full opening for the dynamic pallet opening when the VCM supply is stepped, and calculated from the moment of the pallet opening process.

Markings on the drawing:



[0018] 
  1. 1 - pipe,
  2. 2 - return spring,
  3. 3 - valve pallet,
  4. 4 - windlass
  5. 5 - linkage,
  6. 6 - key,
  7. 7 - pipe,
  8. 8 - valve pallet,
  9. 9 - VCM,
  10. 10 - link,
  11. 11 - key displacement sensor,
  12. 12- key,
  13. 13 - microprocessor.



Claims

1. A mechatronic action for a pipe organ, characterised in that, for one tone - one key (12) of the keyboard - it consists of a VCM (9) connected by a linkage (10) to a pallet (8) of the valve of the pipe (7) or pipes in the case of a multi-voice organ, a key displacement sensor (11) and a microprocessor system (13) which, on the basis of the signal from the key displacement sensor (11), controls the power supply to the VCM (9).
 
2. Method of controlling the power supply of the VCM in the mechatronic action of a pipe organ, characterised by the fact that the microprocessor system, on the basis of the signal from the key displacement sensor, which is information about the key displacement, determines the power supply value of the VCM motor according to the formula:

where: y is the value of the VCM supply (voltage or PWM signal) expressed as a percentage of the maximum supply value, x is the key displacement value measured by the key displacement sensor and expressed as a percentage of the maximum key displacement value, k1 means a signal amplification constant determined during the control system tuning, MIN means the VCM supply value determined by measurements and read from the pallet opening curve, corresponding in the pallet opening process to the maximum VCM supply value for a closed pallet or in the pallet closing process to the maximum VCM supply value for a closed pallet, MAX means the VCM supply value measured and read from the pallet opening curve, corresponding in the pallet opening process to the minimum VCM supply value for a fully open pallet or in the pallet closing process to the minimum VCM supply value for a fully open pallet, whereby the change of MIN and MAX values for changes in the process of opening and closing the pallet occurs after the key displacement equal to or greater than 75% of the maximum key displacement and after the time corresponding to the pallet opening at 50% of the full opening determined from the waveform of the pallet opening at the step forcing of the VCM supply, and counted from the moment of the start of the pallet opening process.
 




Drawing










Search report






Search report




Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description




Non-patent literature cited in the description