Driving method and system for automatic piano performance, and piano

Abstract

The present invention relates to the technical field of smart pianos, and particularly to a driving method and system for automatic piano performance, and a piano. The driving system uses a non-destructive built-in driving module. The piano comprises: a sound producing module, which comprises a whippen and a hammer connected to the whippen; and keys, wherein ejector rods are disposed at the rear ends of the keys. The driving module comprises: a mover, wherein the mover is disposed at the rear end of each key, and the mover has an output end disposed opposite the rear end of the key. The mover comprises: a mover assembly, which comprises a permanent magnet, wherein a first end and a second end of the permanent magnet are provided with a first metal segment and a second metal segment, respectively; and a stator assembly, which comprises a guide tube disposed on the outer periphery of the permanent magnet, wherein at least two coils are reversely wound around the guide tube. The present invention provides a non-destructive built-in driving technology, i.e., provides a low-cost miniaturized mover, which can be built in under the key without affecting the original structure of the piano, so as to realize the automatic performance of the keys.

Description

A driving method, driving system, and piano for automatic piano playing.

[0001] Priority application

[0002] This application claims priority to Chinese invention patent applications filed on January 26, 2025, namely, [2025101251819] "A Moving Magnet Linear Motion Device and Automatic Piano Playing Device", [2025101251861] "A Driving Device with Double-Coil Electromagnet and Automatic Piano Playing Device", [2025108994899] "A Driving Method and System for Automatic Piano Playing", [2025108981066] "A Driving System for Automatic Piano Playing and Piano", [2025108981066] "A Driving System for Automatic Piano Playing and Piano", all of which are incorporated herein by reference in their entirety. Technical Field

[0003] This invention relates to the field of piano playing device technology, specifically to a driving method, driving system, and piano for automatic piano playing. Background Technology

[0004] Intelligent pianos typically use motors to drive the keys, thus enabling them to play music automatically.

[0005] For example, CN211319709U discloses an automatic playing drive device, including a fixed frame, an electromagnetic component, a top cap component, and an adjustment component. The adjustment component includes a compression spring, a control rod, and a control disc. The upper end of the control rod has a first threaded end, which passes through the lower base plate and extends into the movable iron core, where it is threadedly connected. The control disc is fitted onto the surface of the control rod, and the two ends of the compression spring abut against the lower base plate and the control disc, respectively. As another example, patent application CN216772790U discloses an external automatic piano player, including a frame, at least one row of fingers for striking the keys, and at least one electromagnetic drive plate. The at least one row of fingers is fixed to the frame, and the electromagnetic drive plate is electrically connected to one or more fingers. Each finger includes a cylinder, a coil, and a playing needle. The coil is fitted onto the outer wall of the cylinder and is electrically connected to the electromagnetic drive plate. For example, patent application CN215643915U discloses an electromagnet for an automatic piano playing system. It includes a plastic nut with a foam rubber ring and a threaded tube mounted on it. A round iron tube is mounted on the threaded tube, and a movable iron core is located inside the round iron tube. A copper tube is located outside the movable iron core, and a round iron plate is located at the top of the round iron tube. An aluminum strip is located on the movable iron core, with its top end penetrating the round iron plate. A spool is located outside the copper tube, and enameled wire is located outside the spool. A conductor assembly is located on the spool. A rubber pad is located at the top of the aluminum strip, and a felt pad is located at the top of the rubber pad. However, this electromagnet drive device results in low quality automatic piano playing.

[0006] In conclusion, traditional automatic playing techniques struggle to replicate the real finger playing skills of a human, resulting in a lack of emotion and a mechanical playing style. Summary of the Invention

[0007] The purpose of this invention is to provide a driving method, driving system, and piano for automatic piano playing, partially solving or alleviating the aforementioned deficiencies in the prior art. To solve the aforementioned technical problems, this invention specifically adopts the following technical solution: In a first aspect, this invention provides a driving system for automatic piano playing, the driving system employing a lossless built-in driving module, wherein the piano includes: a sound-producing module, the sound-producing module including: a linkage and hammers connected to the linkage; piano keys, the rear end of which is provided with a push rod; the driving module includes: a motion device, the motion device being disposed at the rear end of the piano keys, and the motion device having an output end disposed opposite to the rear end of the piano keys; wherein the motion device includes: a mover assembly, the mover assembly including: a permanent magnet, the first end and the second end of the permanent magnet respectively provided with a first metal segment and a... The second metal segment; the stator assembly, comprising: a conduit disposed on the periphery of the permanent magnet, wherein at least two sets of coils are wound in reverse, the at least two sets of coils including a first set of coils and a second set of coils, the first set of coils being wound around the conduit in a first winding direction, and the second set of coils being wound around the conduit in a second winding direction; the input terminal of the first set of coils being connected to a first pole of a power supply, the output terminal of the second set of coils being connected to a second pole of the power supply, the output terminal of the first set of coils and the input terminal of the second set of coils being connected, and the first winding direction being opposite to the second winding direction; and the axial length of the rotor assembly being less than the axial length of the at least two sets of coils.

[0008] In some embodiments, the axial length of the first metal segment is greater than the axial length of the second metal segment. In some embodiments, the material of the first or second metal segment is iron. In some embodiments, the axial length of the mover assembly is greater than the axial length of the first or second set of coils, such that the two ends of the mover assembly are located in different coil regions.

[0009] In some embodiments, the actuator further includes: a control unit for controlling the input current of the coil to control the movement of the actuator assembly. In some embodiments, the drive system further includes: at least two primary control modules, one of which is connected to multiple control units; and a secondary control module connected to the primary control module. In some embodiments, the primary control module further includes or is connected to a data storage module for storing first external data of at least one piano key, the first external data being historical motion data of the piano key; and / or, further includes: a position monitor for monitoring the position of the piano key.

[0010] In some embodiments, the primary control module is connected to a data storage module, a data processing module, and a monitoring module; correspondingly, the drive system includes: a data storage module for acquiring first external data generated corresponding to at least one key during a first performance time, the first external data describing the position change of the key during the first performance time; a data processing module for converting the first external data into discrete data, the discrete data including: multiple discrete positions, the discrete positions being associated with time-series tags; a sending module for sending at least one of the discrete data to the main control module, the main control module forwarding the discrete data to the control unit of the motion device; a monitoring module for monitoring second external data of the key at a first moment, and finding the corresponding discrete position based on the first moment through the time-series tags; the second external data being the position of the key; a closed-loop control module for calculating the difference between the second external data and the corresponding discrete position, and using a closed-loop control algorithm to output the adjustment current value for the next time period through the difference; and a drive module for the control unit to drive the motion device in response to the adjustment current value. In some embodiments, it further includes: a sleeve disposed outside the coil. In some embodiments, the output terminal includes a connecting rod extending along the mover assembly, wherein a buffer module is provided at the end of the connecting rod corresponding to the piano key.

[0011] The present invention also provides a piano having a drive system as described in any of the embodiments.

[0012] A second aspect of the present invention provides a control method for automatic piano playing, the piano including multiple keys, and a motion device disposed below each key, the motion device being connected to a control unit, and the output end of the motion device pushing the keys under the control of the control unit, the piano including a main control module, and one main control module being connected to multiple control units, the method comprising: S101, acquiring first external data generated corresponding to at least one key during a first playing time, the first external data being used to describe the positional change of the key during the first playing time; S102, converting the first external data into discrete data, and the discrete data... The data includes: multiple discrete positions, each discrete position being associated with a time-series tag; S103, sending at least one of the discrete data to the main control module, the main control module forwarding the discrete data to the control unit; S104, monitoring the second external data of the piano key at a first moment, and finding the corresponding discrete position based on the first moment through the time-series tag; the second external data is the position of the piano key; S105, calculating the difference between the second external data and the corresponding discrete position, and using a closed-loop control algorithm to output the adjustment current value for the next time period through the difference; S106, the control unit driving the motion device in response to the adjustment current value.

[0013] In some embodiments, the method further includes: S107, determining whether the second external data is greater than or equal to a preset target position; S108, if the result of S107 is yes, then identifying the recording time corresponding to the second external data as the detection time; S109, determining whether the detection time to the current time exceeds a preset time threshold; S110, if the result of S109 is yes, then identifying the first current at the current time, and generating a second current based on the first current using a preset current limiting rule, wherein the magnitude of the second current is less than the first current, and inputting the second current into the control unit as a new adjustment current value. In some embodiments, the method further includes: monitoring whether the difference between the second external data and the third external data collected in the next time period exceeds a preset position threshold; if so, then updating the current limiting rule.

[0014] In some embodiments, the current limiting rule is the second current = first current × set ratio; correspondingly, the step of updating the current limiting rule includes increasing or decreasing the set ratio. In some embodiments, the step further includes: when the difference between the set ratio before the update and the set ratio after the update is greater than a preset first ratio threshold, a first prompt signal is generated; when the number of first prompt signals generated in a first time period is greater than a preset number of first signals, a recommended update scheme is generated, and the recommended update scheme is forwarded to at least one of the control units through the main control module, the recommended update scheme including: a suggested adjustment value for the set ratio.

[0015] In some embodiments, the method further includes the steps of: generating a second prompt signal when the difference between the set ratio before the update and the set ratio after the update is greater than a preset second ratio threshold; and generating a motion detection signal when the number of second prompt signals generated within a first time period is less than a preset number of second signals, to prompt the user to detect the corresponding motion device. In some embodiments, the piano includes at least two parallel main control modules.

[0016] This invention also provides a control system for automatic piano playing. The piano includes multiple keys, and a motion device is disposed below each key. The motion device is connected to a control unit, and the output of the motion device pushes the keys under the control of the control unit. The piano includes a main control module, and one main control module is connected to multiple control units. Correspondingly, the system includes: a data storage module for acquiring first external data generated corresponding to at least one key during a first playing time, the first external data being used to describe the positional change of the key during the first playing time; and a data processing module for converting the first external data into discrete data, the discrete data including: multiple... A discrete position, wherein the discrete position is associated with a time sequence tag; a sending module, used to send at least one of the discrete data to the main control module, the main control module forwarding the discrete data to the control unit of the motion device; a monitoring module, used to monitor the second external data of the piano key at a first moment, and find the corresponding discrete position based on the first moment through the time sequence tag; the second external data is the position of the piano key; a closed-loop control module, used to calculate the difference between the second external data and the corresponding discrete position, and use a closed-loop control algorithm to output the adjustment current value for the next time period through the difference; a driving module, used by the control unit to drive the motion device in response to the adjustment current value.

[0017] In some embodiments, the system further includes: a first judgment module, configured to determine whether the second external data is greater than or equal to a preset target position; a detection module, configured to identify the recording time corresponding to the second external data as a detection time if the result of the judgment module is yes; a second judgment module, configured to determine whether the detection time to the current time exceeds a preset time threshold; and a limiting module, configured to identify a first current at the current time if the result of the second judgment module is yes, and generate a second current based on the first current using a preset current limiting rule, wherein the magnitude of the second current is less than the first current, and input the second current into the control unit as a new adjustment current value.

[0018] In some embodiments, the system further includes: a rule update module, used to monitor whether the difference between the second external data and the third external data collected in the next time period exceeds a preset position threshold; if so, the current limiting rule is updated.

[0019] Beneficial Technical Effects: This invention provides a distributed drive system to meet the needs of automatic piano playing. Specifically, the drive system's functions are spatially arranged by independently placing two modules within the piano: a motion actuator and a position monitor (or, in other words, providing a distributed design). External data collected by the position monitor serves as input guidance for the motion actuator. This simplifies the motion actuator's structural design, reduces production costs, and, more importantly, avoids the risk of localized overheating during prolonged automatic piano playing.

[0020] Specifically, this invention also employs a three-segment mover assembly design with a single permanent magnet connecting the upper and lower metal segments, combined with a reverse winding scheme (i.e., coil reverse winding). This limited staggered design can significantly improve the linearity of the mover assembly's motion thread without excessively increasing the complexity of the motion mechanism structure. This improved linearity is more conducive to replicating the finger movement trajectory, thereby improving the sound quality during automatic playing.

[0021] For the aforementioned distributed drive system, this invention also provides a discrete closed-loop adjustment path based on external data. This discrete closed-loop adjustment path can simulate the actual playing state of the fingers to a large extent, while reducing the dependence on the confidence level (such as communication speed or reliability) of external data communication to a certain extent.

[0022] From another perspective, this discrete closed-loop adjustment path can match the physiological characteristics of the fingers (i.e., relatively limited speed), so as to improve the performance quality of automatic playing under simple closed-loop control, without increasing costs or operational risks too much.

[0023] For discrete closed-loop control, this invention focuses on limiting the current of the actuator at the maximum position (i.e., the deepest range of key pressing). On the one hand, this limits the high-power operation time of the actuator, and on the other hand, by limiting the current in this special range of the maximum position, it can also reduce interference with the dominant target of the actuator simulating finger movement. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0025] Figure 1 is a schematic diagram of the first overall structure of a moving magnetic linear motion device according to one embodiment of the present invention;

[0026] Figure 2 is a first cross-sectional view of a moving magnetic linear motion device according to one embodiment of the present invention;

[0027] Figure 3 is a second cross-sectional view of a moving magnetic linear motion device according to one embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of the second overall structure of the magnetic linear motion device according to one embodiment of the present invention.

[0029] Figure 5 is a schematic diagram of the first structure of a moving magnetic linear motion device according to one embodiment of the present invention;

[0030] Figure 6 is a schematic diagram of the second structure of the moving magnetic linear motion device according to one embodiment of the present invention;

[0031] Figure 7 is a simulated magnetic field line distribution diagram of the permanent magnet in the first position in one embodiment of the present invention;

[0032] Figure 8 is a simulated magnetic field line distribution diagram of the permanent magnet in the second position in one embodiment of the present invention;

[0033] Figure 9 is a simulated magnetic field line distribution diagram of the permanent magnet in the third position in one embodiment of the present invention;

[0034] Figure 10 is a schematic diagram of the structure of an automatic piano playing device according to one embodiment of the present invention;

[0035] Figure 11 is a schematic diagram of the installation scheme of the motion device inside the piano in an exemplary embodiment of the present invention;

[0036] Figure 12 is a schematic diagram of the outer shell of the motion device in an exemplary embodiment of the present invention;

[0037] Figure 13 is a schematic cross-sectional view of the motion device in an exemplary embodiment of the present invention;

[0038] Figure 14 is a flowchart illustrating the driving method in an exemplary embodiment of the present invention;

[0039] Figure 15 is a schematic diagram of the module architecture of the driving system in an exemplary embodiment of the present invention;

[0040] Figure 16 is a schematic diagram of the first structure of a driving device according to one embodiment of the present invention;

[0041] Figure 17 is a schematic diagram of the second structure of the driving device according to one embodiment of the present invention;

[0042] Figure 18 is a schematic diagram of the structure of an auxiliary component according to one embodiment of the present invention;

[0043] Figure 19 is a schematic diagram of the movement state of the iron core from the first position, the second position to the third position according to one embodiment of the present invention;

[0044] Figure 20 is a schematic diagram of the third structure of the driving device according to one embodiment of the present invention;

[0045] Figure 21 is a schematic diagram of the structure of a drive component according to one embodiment of the present invention;

[0046] Figure 22 is a simulated magnetic field line distribution diagram during the core rising process of one embodiment of the present invention;

[0047] Figure 23 is a simulated magnetic field line distribution diagram during the process of the iron core falling back, hovering, and slowly descending according to one embodiment of the present invention.

[0048] First set of attached reference numerals: 1. Permanent magnet; 10. Connecting rod; 11. Iron column; 11a. First metal segment; 11b. Second metal segment; 2. Conduit; 30. First coil; 31. Second coil; 4. Sleeve; 5. First buffer; 6. Second buffer; 01. Piano key; 02. Top rod; 03. Linkage device; 04. Hammer; 05. Motion device; 051. Output end. Second set of reference numerals: 1A, First iron core; 10A, Connecting part; 11A, First coil group; 12A, First support member; 13A, First sleeve; 130A, First upper top plate; 131A, First lower bottom plate; 132A, First side plate; 14A, Top rod; 15A, Isolation part; 2A, Second iron core; 21A, Second coil group; 22A, Second support member; 23A, Second sleeve; 230A, Second upper top plate; 231A, Second lower bottom plate; 232A, Second side plate; 3A, First buffer member; 4A, Second buffer member. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0050] In this document, suffixes such as "module," "component," or "unit" used to denote elements are used solely for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "component," or "unit" can be used interchangeably. In this document, terms such as "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In this document, unless otherwise expressly specified and limited, terms such as "installed," "equipped with," and "connected" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] In this document, "and / or" includes any and all combinations of one or more of the listed related items. "A plurality of" in this document means two or more, i.e., it includes two, three, four, five, etc. As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4%, more typically + / -3%, more typically + / -2%, even more typically + / -1%, even more typically + / -0.5%. In this specification, certain embodiments may be disclosed in a range format. It should be understood that this "range" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of the range should be considered as having specifically disclosed all possible subranges and independent numerical values ​​within those ranges. For example, a description of the range 1 to 6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. The above rules apply regardless of the breadth of the range.

[0052] Length: As used in this document, “length” refers to the length along the axial direction of the permanent magnet.

[0053] To facilitate understanding of the workflow of the actuator (or driver or drive motor, as shown in Figures 12 and 13) used in this invention, the piano's sound production process is briefly described below with reference to Figure 11: The piano includes: keys 01, with a push rod 02 at the rear end of each key 01; when the front end of key 01 is pressed, its rear end tilts upward to push the linkage 03 via the push rod 02, which in turn drives the hammer 04 (a felt-covered wooden mallet) to rapidly strike the strings (not shown in the figure). It is understood that the depth and force of the key press directly affect the hammer's striking speed and intensity, thereby controlling the volume and timbre of the sound. After the key is released, the damper falls back to press down on the strings, terminating the sound. In an exemplary embodiment provided herein, the actuator 05 can be positioned below the rear end of key 01, so that when the output end 051 of the actuator 05 moves upward, it can cause the rear end of key 01 to tilt upward (i.e., push the key), thus simulating the effect of a finger pressing a key. For example, the piano in this embodiment can be an upright piano or a grand piano.

[0054] Example 1: Referring to Figure 11, a drive system for automatic piano playing is shown. The drive system drives a module to control the sound production. The piano includes: a sound production module, which includes: a linkage 03 and a hammer 04 connected to the linkage 03; piano keys 01, with a push rod 02 at the rear end of each key; the drive module includes: a motion device 05, which is disposed at the rear end of each key 01 and has an output end opposite to the rear end of each key 01; wherein the motion device includes:

[0055] The mover assembly, as shown in Figure 1, includes: a permanent magnet 1, with a first metal segment 11a and a second metal segment 11b respectively at its first and second ends; and a stator assembly, including: a conduit 2 disposed on the outer periphery of the permanent magnet 1, with at least two sets of coils wound in the reverse direction on the conduit 2. Preferably, the at least two sets of coils include a first set of coils 30 and a second set of coils 31. The first set of coils 30 is wound around the conduit in a first winding direction, and the second set of coils 31 is wound around the conduit in a second winding direction. The input end of the first set of coils is connected to the first pole of a power supply, and the output end of the second set of coils is connected to the second pole of the power supply. The output end of the first set of coils and the input end of the second set of coils are connected, and the first winding direction is opposite to the second winding direction. Preferably, the axial length of the mover assembly is less than the axial length of the at least two sets of coils. The output end of the actuator can be directly or indirectly connected to the mover assembly to drive the piano keys to rotate under the action of the mover assembly.

[0056] It should be noted that this embodiment employs a non-destructive built-in drive module. "Non-destructive built-in" means that the drive module is located inside the piano (e.g., in the space under the keys) and does not cause excessive interference or damage to the piano's original structure. For example, the drive module can drive the keys through contact (e.g., the output of the drive module can contact the keys to drive them).

[0057] In some embodiments, the actuator further includes: a control unit for controlling the input current of the coil to control the movement of the actuator assembly. In some embodiments, the drive system further includes: at least two primary control modules, one of which is connected to multiple control units; and a secondary control module connected to the primary control module.

[0058] Specifically, a piano typically has 88 keys, each equipped with one actuator, meaning there are 88 actuators spaced apart below the keys. This embodiment preferably uses four primary control modules (e.g., embedded microcontrollers) each connected to 22 actuators (specifically, connected to their control units), thus achieving four sets of parallel control. Furthermore, the four primary control modules can communicate with one secondary control module for centralized control. The secondary control module can be a computer, mobile phone, tablet, or other device, or it can be a control module installed on the piano that can communicate with such devices.

[0059] In some embodiments, the primary control module further includes or is connected to a data storage module, which is used to store historical motion data (or first external data) of at least one piano key. The historical motion data refers to the position of the piano key at various moments, recorded directly or indirectly by a sensor when the user presses the key.

[0060] It is worth noting that, unlike the traditional integrated motor concept (i.e., setting an encoder on the motor output shaft and using the encoder data to perform internal feedback adjustment of the motor to help achieve closed-loop control of motor speed), this invention focuses on disassembling and updating the layout of the motor's functions to meet the needs of piano key simulation: Specifically, the motion unit is connected to a control unit, which adjusts the motion parameters (such as the position) of the moving part by adjusting the current of the input coil; correspondingly, this invention selects an external position monitor, and enables the position monitor to communicate directly or indirectly with the moving part, which can monitor or reflect the motion data of the piano keys (such as the position at various times).

[0061] It is worth noting that this invention adapts to the needs of automatic piano playing by spatially arranging the functions of the drive system. Specifically, it independently sets up two modules within the piano: a motion actuator and a position monitor (or provides a distributed design). External data collected by the position monitor serves as input guidance for the motion actuator. Therefore, this invention simplifies the structural design of the motion actuator, reduces production costs, and, more importantly, avoids the risk of localized overheating during prolonged automatic piano playing.

[0062] It is important to note that the core components of a piano, such as the keys, are made of wood, which is flammable. This distributed design can reduce safety risks while enhancing the functionality of the smart piano. For example, the functionality refers to the ability of the external position monitor to simultaneously collect both the user's actual playing data (i.e., historical motion data) and the automatic playing data from the movement device.

[0063] For example, in some embodiments, the position monitor is a sensor located below the piano keys, configured to detect the displacement, velocity, or acceleration of the keys, and the position of the keys at any given moment can be calculated directly or indirectly based on the displacement, velocity, or acceleration; the sensor is used to connect to the control unit of the motion device. In some embodiments, the sensor can be a velocity sensor, a displacement sensor, or an acceleration sensor. Further, in some embodiments, the velocity sensor includes, but is not limited to, one or more of the following: magnetoelectric velocity sensor, Hall effect velocity sensor, photoelectric velocity sensor, and magnetoelectric velocity sensor. Further, in some embodiments, the displacement sensor includes, but is not limited to, one or more of the following: potentiometer displacement sensor, inductive displacement sensor, capacitive displacement sensor, magnetostrictive displacement sensor, optical sensor, ultrasonic sensor, Hall effect displacement sensor, oscillator displacement sensor, photoelectric encoder, contact sensor, and non-contact sensor, such as eddy current displacement sensor, laser displacement sensor, and ultrasonic displacement sensor, which do not directly contact the object being measured. As another example, in some embodiments, the position monitor can be a grating velocimeter. For example, the grating velocimeter can be located on the side of the hammer to measure the moving speed of the hammer. Furthermore, in some embodiments, the displacement of the piano keys at various times can be indirectly calculated by measuring the moving speed of the hammer.

[0064] In some embodiments, the thickness of the first metal segment 11a is greater than the thickness of the second metal segment 11b. In some embodiments, the material of the first or second metal segment is iron. In some embodiments, the axial length of the mover assembly is greater than the axial length of the first or second set of coils, so that the two ends of the mover assembly are located in different coil regions. Preferably, the present invention adopts a three-segment mover assembly design with a single permanent magnet connecting the upper and lower metal segments, and is combined with a reverse winding scheme (i.e., coil reverse winding). This limited staggered design can significantly improve the linearity of the mover assembly's motion thread without excessively increasing the complexity of the motion device structure. This improvement in linearity is more conducive to realizing the replication of the finger movement trajectory by the motion device, thereby improving the sound quality during automatic playing.

[0065] In other words, this invention employs an innovative three-segment mover assembly design, with the core consisting of a single permanent magnet and connecting metal segments at the top and bottom, and integrating a reverse winding scheme (i.e., the coil is wound in reverse). This design achieves a balance between structural simplicity and functional efficiency through a limited staggered layout—effectively optimizing the magnetic field distribution and energy transfer path without significantly increasing the mechanical complexity of the mover.

[0066] Among them, the reverse winding scheme forms a complementary effect with the permanent magnet through the reverse magnetic field coupling generated by winding the coil in the reverse direction, significantly improving the linearity of the moving element assembly's motion thread. This linear optimization stems from the balanced distribution of magnetic force, reducing the non-linear deviation (such as inertial interference) during the movement, thereby more accurately simulating the continuous motion trajectory. Thus, the present invention improves the efficiency through the ingenious design of staggered layout rather than brute-force expansion (such as increasing the number of coil groups). Furthermore, the improvement in linearity directly enhances the dynamic replication ability of the actuator for the finger movement trajectory. Especially in an automatic playing system, it can reproduce the subtle movements (such as gradual changes in intensity and rhythm changes) of human playing with high fidelity.

[0067] To more clearly show the driving system provided by the present invention, the structure of the driving system will be introduced in detail below in conjunction with the accompanying drawings: Referring to FIGS. 1-10, the present application provides a moving magnet linear actuator and a piano automatic playing device.

[0068] The present invention provides a moving magnet linear actuator. As shown in FIG. 1, the actuator includes at least one set of moving element assemblies, and a set of stator assemblies arranged outside the moving element assemblies. The moving element assemblies include at least one permanent magnet 1. The stator assemblies include a coil module and a sleeve 4. The coil module includes a conduit 2 and a coil group wound around the conduit. For example, the coil group can be at least two sets of coils arranged along the axial direction of the permanent magnet. The permanent magnet 1 is arranged inside the conduit 2, and the sleeve 4 is arranged outside the conduit 2. The at least two sets of coils are connected to a power supply for supplying power to them. The at least two sets of coils include a first set of coils 30 and a second set of coils 31. The first set of coils 30 is wound around the conduit in a first winding direction, and the second set of coils 31 is wound around the conduit in a second winding direction. Among them, the output end of the first set of coils is connected to the input end of the second set of coils, and the first winding direction is opposite to the second winding direction.

[0069] Preferably, the total length of the at least two sets of coils is L1, the length of each set of coils in the at least two sets of coils is L2, and the length of the permanent magnet is L3, where L2 < L3 < L1, such that the two end magnetic poles of the permanent magnet are respectively in different sets of coil groups. When the at least two sets of coils are energized, the generated electromagnetic field can make the first end magnetic pole of the permanent magnet receive a first thrust force exerted by the first set of coils, and the second end magnetic pole of the permanent magnet receive a second thrust force exerted by the second set of coils. Among them, the directions of the first thrust force and the second thrust force are the same to drive the permanent magnet to perform linear motion.

[0070] The total length L1 of at least two sets of coils, or the length L2 of each set of coils, as mentioned herein, refers to the length of the winding area formed after the wire is wrapped around the conduit in the axial direction of the permanent magnet.

[0071] In some embodiments, the output end of the first set of coils is connected to the input end of the second set of coils, that is, the end of the first set of coils extends along the axial direction of the permanent magnet 1 and is connected to the beginning end of the second set of coils.

[0072] In some embodiments, the first winding direction is opposite to the second winding direction, such that the current direction (or current winding direction) in the first group of coils and the second group of coils is opposite after energization. Specifically, in other embodiments, if the current winding direction in the winding area of ​​the first group of coils is clockwise, then the current winding direction in the winding area of ​​the second group of coils is counterclockwise.

[0073] In some embodiments, the permanent magnet is cylindrical and magnetized in an up-down direction, i.e., the upper end of the permanent magnet is the N pole and the lower end is the S pole. In some embodiments, the surface of the permanent magnet is coated with a smooth, wear-resistant coating. Further, in some embodiments, the diameter of the cylindrical permanent magnet is slightly smaller than the inner diameter of the conduit wall, which, when used with the conduit, allows the permanent magnet to move freely up and down within the conduit and its lateral swing amplitude to be within an acceptable range. In some embodiments, the conduit is made of plastic or other non-magnetic material, with a smooth inner wall and a diameter slightly larger than the diameter of the permanent magnet.

[0074] In some embodiments, the at least two sets of coils can be obtained by winding a wire in opposite directions on a conduit. In other embodiments, the at least two sets of coils can be obtained by first winding two wires in opposite directions on a conduit, and then connecting the end of one wire (i.e., the output end) and the beginning of the other wire (i.e., the input end) with a connecting wire. In other embodiments, the assembly of the conduit and coils is also referred to as a solenoid, and the solenoid and the cylindrical permanent magnet form the body of the moving magnetic linear motion device, with the solenoid as the stator and the cylindrical permanent magnet as the mover. In some embodiments, the sleeve is a cylindrical iron frame that wraps around the solenoid to form a magnetic conductive path outside the solenoid, thereby enhancing the magnetic field strength generated by the solenoid. In some embodiments, the number of coil sets can increase in an even number; this embodiment shows two sets of coils, but to increase thrust, there can also be 4, 6, 8... sets of coils, with the current direction of adjacent coils being opposite (i.e., the winding direction of adjacent coils being opposite). Correspondingly, the number of permanent magnets needs to be half the number of coil sets, so that each magnetic pole is within a set of coils.

[0075] In some embodiments, the mover assembly further includes a buffer module. The buffer module is connected to the mover assembly through a connecting rod 10, and the buffer module is arranged corresponding to the keys for pushing the keys. Further, the buffer module includes a first buffer member 5 and a second buffer member 6. The first buffer member 5 is connected to the permanent magnet through the connecting rod 10, and the second buffer member 6 is connected to the first buffer member 5. In some embodiments, the connecting rod is made of a material with sufficient strength such as metal.

[0076] In some embodiments, the mover assembly further includes a first metal segment 11a and a second metal segment 11b arranged at two ends of the permanent magnet. Specifically, the first metal segment and the second metal segment are iron columns 11 (as shown in Figure 3). The total length of the iron column and the permanent magnet is L4 (as shown in Figure 2), and L2 < L4 < L1.

[0077] In some embodiments, the length L of the permanent magnet needs to match the height H of the mover. Here, the length L is the total length of the permanent magnet and the possible iron columns installed at both ends of the permanent magnet, and the height H also refers to the total length L1 of the at least two sets of coils. The permanent magnet does not exceed the range of the at least two sets of coils, so L is less than H (that is, L < L1); the moving area of the permanent magnet is H minus L, and within this area, the permanent magnet is in a controllable state. L also cannot be less than the length L2 of each set of coils, that is, half of H, to prevent the N pole and S pole of the permanent magnet from being within the range of the same set of coils (that is, to prevent the permanent magnet from stopping in place and being uncontrollable).

[0078] In other words, the length of the mover assembly is preferably greater than the length of one set of coils and less than the total length of two sets of coils, so that at least most of the time, both ends of the mover assembly can be located in two different coil regions respectively. On the basis of improving the operating efficiency of the mover assembly, the problem of the mover assembly getting stuck is avoided.

[0079] In the existing electromagnet driving scheme based on an iron core, the falling position of the keys cannot be effectively controlled, resulting in a single or discontinuous sound for each key. Eventually, a performance segment with a special timbre effect cannot be played, which cannot meet the performance requirements, and the automatic playing skills are relatively single.

[0080] This invention provides a precisely controlled moving-magnet linear motion device based on a reverse winding method using a shared power source and a permanent magnet design. By winding the first and second sets of coils in opposite directions and connecting their output and input ends, the current directions in the winding areas of the two sets of coils are opposite (i.e., the current direction of the first set of coils is clockwise, and the current direction of the second set of coils is counterclockwise). By adjusting the length of the permanent magnet and the coils, the force direction on the permanent magnet is made consistent, resulting in a greater thrust under a fixed current. By changing the current magnitude, the magnitude of the thrust on the permanent magnet can be changed, thereby quickly and accurately adjusting the rise and fall of the permanent magnet. Based on the moving-magnet linear motion device, this invention also provides an automatic piano playing device. This device achieves precise control of the timing relationship of the key fall position by changing the magnitude of the overall thrust on the current-driven permanent magnet. It can more accurately simulate the finger lifting process of a human hand playing the piano, making the piano sound have dynamics and automatically playing piano music with intonation and nuance, thus improving the sound quality of automatic piano playing.

[0081] In some embodiments, the number of coil turns can be designed to vary depending on the required force and the supply voltage. Under the same voltage and current, more turns result in a greater force. However, generally, with a fixed supply voltage, more turns lead to higher resistance and lower current, requiring a balance to be struck based on the actual heat generation.

[0082] Preferably, in some embodiments, the number of turns in each of the at least two sets of coils is the same and is N, where 100≤N≤5000. In some embodiments, the coils are generally made of copper enameled wire, and the specifications can be selected from commonly available models as needed. The larger the coil wire diameter, the lower the resistivity, the lower the resistance for the same length (referring to the wire length between the beginning and end of the coil), the larger the current, and the greater the thrust obtained by the permanent magnet. Preferably, in some embodiments, the bare wire diameter of the at least two sets of coils is 0.008mm–2mm, and the DC resistance of the at least two sets of coils is 3-200Ω.

[0083] In some embodiments, a thermosetting filler material is further disposed between the conduit 2 and the sleeve 4. In some embodiments, the thermosetting filler material is required to be insulating and non-magnetic, and capable of withstanding high temperatures (above 120°C). Specifically, in some embodiments, the thermosetting filler material is a gel-like substance, such as silicone.

[0084] In some embodiments, different DC voltages can be provided depending on the actual scenario. With a fixed number of coil turns, the higher the voltage, the higher the current, and the greater the thrust obtained by the permanent magnet. However, excessively high voltage will increase the insulation requirements of the coil, and excessively high voltage and current will also increase heat generation, posing a risk of overheating and burning out the motion device. Preferably, in some embodiments, the voltage U provided by the power supply is in the range of 3V≤U≤110V, and the current I is in the range of 0A≤I≤20A.

[0085] In some embodiments, the at least one permanent magnet is connected to each other by a non-ferromagnetic material. In some embodiments, the at least one permanent magnet is fitted with a shell. In other embodiments, the shell is made of a non-ferromagnetic material. Specifically, in applications where the permanent magnet may require drastic acceleration or deceleration, the permanent magnet may not be strong enough. Therefore, a shell made of a material with low magnetic permeability, such as copper or stainless steel, can be fitted onto the permanent magnet to increase its strength.

[0086] In some embodiments, the first and second buffers are made of flexible materials. In some embodiments, the first buffer may be a soft material such as wool felt, foam, or silicone. In other embodiments, the second buffer may also be a soft material such as silicone, rubber, or foam.

[0087] In some embodiments, the magnitude of the force exerted on the permanent magnet varies depending on its position. Specifically, as shown in Figures 7-9, the simulated magnetic field line distribution diagram shows that the lower the position of the permanent magnet, the greater the upward component of the magnetic field lines, and the greater the upward thrust of the coil on the permanent magnet.

[0088] In summary, when the at least two sets of coils are energized, the cylindrical permanent magnet experiences a reaction force. According to Ampere's force formula, the N-pole portion (i.e., the first end pole) of the permanent magnet experiences an upward (i.e., in the direction away from the stator assembly) thrust from the upper coil (i.e., the first set of coils), and the S-pole portion (i.e., the second end pole) experiences an upward (i.e., in the direction away from the stator assembly) thrust from the lower coil (i.e., the second set of coils). The magnitude of the thrust is positively correlated with the current magnitude I, the magnetic field strength B, and the size of the overlap area between the permanent magnet and the coils. By changing the duty cycle of the power switch or the power supply voltage, the current magnitude in the at least two sets of coils can be changed, thereby changing the magnitude of the thrust on the permanent magnet. Because the magnitude of the thrust is also positively correlated with the size of the overlap area between the permanent magnet and the coils, changing the current can change the size of the overlap area, thus achieving control of the permanent magnet's position by the current.

[0089] The moving magnet linear motion device of this invention, through reasonable design of parameters such as power supply voltage, coil wire diameter (or conductor wire diameter), number of coil turns (or conductor turns), diameter and length of the guide tube and permanent magnet, permanent magnet structure, permanent magnet material and magnetization amount, permanent magnet weight, iron frame shape and thickness, load weight, and the addition or removal of springs, can achieve the desired movement of the permanent magnet. This motion device achieves linear motion with controllable position over a certain distance at a relatively low cost, providing greater thrust within the same equipment volume, meeting the application requirements of many scenarios, and saving significant costs.

[0090] Compared to voice coil motors, moving magnet linear motion machines use permanent magnets as movers, avoiding the wear and tear issues associated with coil connecting wires. They also eliminate the need for guide rails, employing plastic tubes and magnetic pillars for guidance, significantly reducing costs. In vertical assembly applications, the absence of lateral pressure results in very low friction and virtually no wear issues.

[0091] The two sets of coils of the moving magnetic linear motion device of the present invention are connected in parallel, and only the change of one voltage value needs to be controlled, which simplifies the driving complexity; and the two sets of coils are interconnected end to end, so that the current direction is opposite, which can generate thrust on the N and S poles of a cylindrical permanent magnet respectively, thereby doubling the thrust.

[0092] This application also provides an automatic piano playing device, as shown in Figure 10, which illustrates two installation methods of the actuator: Specifically, the device includes the aforementioned actuator, the piano includes piano keys, the actuator can be placed at the end of the piano keys, and the actuator is connected to the end of the piano keys through the second buffer 6; or, the actuator can be placed at the hand-pressing end of the piano keys, and the actuator is connected to the hand-pressing end of the piano keys through the second buffer 6.

[0093] In some embodiments, the actuator and the keys can be in separate contact or directly connected. In some embodiments, the actuator can also be used to drive the piano pedals. In some embodiments, the outer diameter of the actuator, i.e., the diameter of the sleeve, can be freely defined according to installation space constraints; a larger outer diameter allows for more space for winding and a larger diameter of the permanent magnet. In some embodiments, for player pianos modified from traditional pianos, the required thrust to the keys is between 3-30N. The diameter D of the actuator used to drive the keys is limited by installation space, and it is recommended to be 10mm ≤ D ≤ 40mm. In other embodiments, the piano pedals require a larger thrust, in the range of 30-150N, and the diameter D of the actuator used to drive the pedals can be between 40mm ≤ D ≤ 80mm.

[0094] In some embodiments, the height of the actuator is theoretically limited only by the installation space; however, the height can be increased accordingly to increase thrust. In some embodiments, the permanent magnet used in this invention can be a common material available on the market, such as AlNiCo, ferrite, Samarium Cobalt, Neodymium Iron Boron, etc., and can be selected comprehensively based on parameters such as magnetic force, strength, and cost.

[0095] Specifically, in some embodiments, this application functions as follows:

[0096] Rising process: A first current (or rising current) is applied to the at least two sets of coils. The resulting electromagnetic field causes the first end pole of the permanent magnet to be subjected to a first driving force by the first set of coils, and the second end pole of the permanent magnet to be subjected to a second driving force by the second set of coils. The first and second driving forces are in the same direction, driving the permanent magnet to gradually rise from its initial position (as shown in Figure 7) and stop at a first position (as shown in Figure 9).

[0097] In other words, in this embodiment, the upward thrust (the sum of the first driving force and the second driving force) during the upward process can drive the permanent magnet to drive the connecting rod to gradually rise and finally stop at the first position. At this time, the connecting rod applies the first pressure to the piano keys, the piano begins to play automatically, and emits the first sound.

[0098] Falling-back process: A second current (or falling-back current) is reapplied to the at least two sets of coils, the second current being less than the first current. At this time, the generated electromagnetic field causes the first end pole of the permanent magnet to experience a first falling-back force applied by the first set of coils, and the second end pole of the permanent magnet to experience a second falling-back force applied by the second set of coils. The first and second falling-back forces are in the same direction, driving the permanent magnet to slowly descend from the first position and stop at the second position (as shown in Figure 8).

[0099] In other words, in this embodiment, the downward thrust during the descent process (i.e., the sum of the first and second descent forces) is less than the upward thrust during the ascent process. Reducing the current allows the permanent magnet to slowly lower the connecting rod from the first position and eventually stop at the second position, without immediately returning the permanent magnet to its initial position. The connecting rod applies a second pressure to the piano key, which is less than the first pressure. This effectively controls the key's descent, preventing an uncontrollable and complete fall. At this time, the piano will not immediately stop playing, but will produce a second sound with continuity or a special timbre.

[0100] In other words, the solution of this application enables the permanent magnet to generate a greater thrust for the same device volume by simply applying a fixed current to the coil. This thrust can cause the permanent magnet to move in a straight line. Therefore, during automatic piano playing, the magnitude of the overall thrust on the permanent magnet can be changed by altering the current, thus controlling the fall of the permanent magnet and achieving effective control over the fall of the piano keys.

[0101] This invention, based on a reverse winding method using a shared power source and a permanent magnet design, primarily aims to address the problem of severe nonlinearity of forces experienced by ordinary electromagnets during motion, resulting in excessively drastic changes in the force-position curve and an inability to effectively control the fallback. This design, however, allows for minimal force variation during motion, enabling effective fallback control of the permanent magnet.

[0102] Furthermore, the reverse winding method and the design of the permanent magnet in this application can effectively control the return of the piano keys during piano playing, ensuring that the same key can produce different sounds, which can meet the requirements of automatic playing of complex scores and make the quality of automatically played piano music higher.

[0103] In some embodiments, the first buffer is a pad used to eliminate impact noise during the fall of the permanent magnet. In some embodiments, the second buffer is a cap used to eliminate impact noise between the permanent magnet and the piano keys during the rise of the permanent magnet.

[0104] This invention achieves a qualitative improvement in the automatic piano playing effect at a relatively low cost. Compared to the shortcomings of existing electromagnet-based automatic piano key driving schemes, which suffer from the near-uncontrollable key return, this scheme can precisely control the timing and position of the key return by changing the current magnitude. This allows for a more accurate simulation of the finger lifting process of a human hand, achieving a perfect replication of the performance.

[0105] Compared to existing automatic piano key drive solutions based on traditional linear motors, which suffer from high cost, large size, low thrust-to-volume ratio, and complex drive processes, this solution's moving magnet linear actuator offers advantages such as low cost, simple manufacturing process, small size, high thrust-to-volume ratio, and simple drive. Furthermore, compared to traditional electromagnets, this solution provides a faster drive response speed. This is because traditional electromagnets require a magnetization process after energizing the iron core before generating attraction, while this solution uses permanent magnets, eliminating the need for magnetization and generating force more quickly upon energization. For automatic piano playing applications, the faster response speed allows for more accurate reproduction of the user's hand movements, reduces system latency, and produces a better playing effect.

[0106] To address issues of heat generation and reliability, this solution involves injecting a thermosetting adhesive between the conduit and the iron frame. This adhesive must be an insulating, non-magnetic material capable of withstanding certain high temperatures. It fills the gap between the coil and the iron frame, improving the overall stability of the motion mechanism and allowing for faster heat transfer from the coil to the iron frame. This results in faster overall heat dissipation, superior to traditional piano electromagnets, and allows operation under higher power conditions.

[0107] It is understood that the linear motion device according to the present invention, and devices and variations thereof that provide linear motion based on the same principle, include, but are not limited to, altering the shape of the permanent magnet and the conduit. For example, attaching multiple iron pillars to both ends of the permanent magnet, increasing the number of coil groups, increasing the number of magnetic pole pairs of the permanent magnet, changing the shape and thickness of the iron frame, and changing the direction of force on the permanent magnet are all within the protection scope of the present invention.

[0108] Example 2: Further, for the aforementioned distributed drive system, this invention also provides a discrete closed-loop adjustment path based on external data. This discrete closed-loop adjustment path can, on the one hand, simulate the actual playing state of the fingers to a large extent, while on the other hand, reducing the dependence on the confidence level of external data communication (such as communication speed or reliability) to a certain extent. From another perspective, this discrete closed-loop adjustment path can conform to the physiological characteristics of the fingers (i.e., relatively limited speed), thereby improving the playing quality of automatic playing under simple closed-loop control without excessively increasing costs or operational risks.

[0109] Specifically, the present invention also provides a driving method for automatic piano playing, wherein the piano includes multiple keys, and a actuator is disposed below each key. The actuator is connected to a control unit, and the output of the actuator pushes the keys under the control of the control unit. The piano includes a main control module (such as a primary main control module), and one main control module is connected to multiple control units. Correspondingly, referring to Figure 14, the driving method includes:

[0110] S101, acquire the first external data (or historical motion data) generated corresponding to at least one key during the first performance time, the first external data being used to describe the position change of the key during the first performance time;

[0111] For example, the first external data could be the position of the piano key at various moments, as captured by the sensor, when the user plays the key (or the first external position). Alternatively, the first external data could be existing performance data collected from a database. For example, the database could record performance data from other performers.

[0112] S102, the first external data is converted into discrete data, and the discrete data includes: multiple discrete locations, the discrete locations being associated with time-series labels; for example, in some embodiments, the position-time relationship curve of the piano keys can be obtained from the position monitor, and the relationship curve can be split into multiple discrete data points, i.e., the discrete positions of multiple points.

[0113] S103, at least one of the discrete data is sent to the main control module, and the main control module forwards the discrete data to the control unit;

[0114] S104, monitor the second external data of the piano key at the first moment, and find the corresponding discrete position according to the first moment through the time sequence label. The second external data is the measured position of the piano key.

[0115] S105, calculate the difference between the second external data (such as the measurement position) and the corresponding discrete position, and use a closed-loop control algorithm to output the compensation current value (or adjustment current value) for the next time period through the difference;

[0116] S106, the control unit drives the motion device in response to the compensation current value. Preferably, the control unit calculates the difference and completes closed-loop control.

[0117] In some embodiments, both the first external data and the second external data can be obtained through a location monitor. In some embodiments, the first external data can be smoothed before being converted into discrete data, such as by filtering the first external data.

[0118] The closed-loop control algorithm in this embodiment can adopt the closed-loop control method in existing motors, and the present invention does not limit it.

[0119] In some embodiments, the method further includes: S107, determining whether the second external data (such as the second external position, i.e. the measured position of the piano key) is greater than or equal to the preset target position;

[0120] S108, if the result of S107 is yes, then the generation or recording time of the corresponding second external data (second external position) is identified as the detection time;

[0121] S109, determine whether the time from the detection time to the current time exceeds a preset time threshold;

[0122] S110, if the result of S109 is yes, then identify the first current at the current moment, and generate a second current based on the first current using a preset current limiting rule, wherein the magnitude of the second current is less than the first current. Then, use the second current as the new adjustment current value.

[0123] In this embodiment, when S109 is true, it may indicate that the actuator has reached its maximum position. For example, in some embodiments, the second current can be 10%, 20%, etc., of the first current to ensure that the force applied by the second current can support the actuator to maintain its current output state, that is, to keep the keys in a state where they do not fall back as much as possible. For example, in some embodiments, when it is detected that the actuator remains at the maximum position (peak) for more than 0.1 seconds, the power is actively reduced (i.e., the current is reduced) to prevent overheating. This low-power maintenance state is beneficial to improving performance safety during performances involving concentrated sustain techniques. For another example, in some embodiments, if the result of S109 is true, the second current preset by the user is selected as the new adjustment current value.

[0124] For example, in some embodiments, the target position can be preset by the user, such as corresponding to the maximum falling position of a piano key. Preferably, for discrete closed-loop control, this embodiment focuses on limiting the current of the actuator at the maximum position (i.e., the range of deepest key pressing). On the one hand, this limits the high-power operation time of the actuator, and on the other hand, by limiting the current in this special range of the maximum position, it can also reduce interference with the dominant target of the actuator simulating finger movement.

[0125] In other words, the discrete closed-loop control in this invention can simulate the key motion characteristics of the fingers to a large extent (such as performing a sustained sound effect), while avoiding the risks of long-term accurate simulation (i.e., long-term high-power operation).

[0126] In some embodiments, the control unit uses the second current to control the motion device. Correspondingly, the method further includes: monitoring whether the difference between the second external position and the third external position collected in the next time period (i.e., before the predetermined falling time of the piano key) exceeds a preset position threshold; that is, whether there is a large deviation between the two. If so, the current limiting rule is updated.

[0127] In other words, by comparing the key position A (the second external position, which can be the depth to which the key is pressed) before the current limit is applied with the key position B (the third external position) after the current limit is applied, if the key position deviates significantly before the expected drop time (such as a certain degree of reduction in the depth of the key press), it is recommended to modify the current limit rules in the next repetition to increase the magnitude of the second current.

[0128] In some embodiments, the current limiting rule is: second current = first current × set ratio; correspondingly, the step of updating the current limiting rule includes: increasing or decreasing the set ratio. For example, if the piano keys quickly fall back after switching to the second current, the set ratio can be increased, i.e., the magnitude of the second current can be increased.

[0129] In some embodiments, the method further includes the steps of: generating a first prompt signal when the difference between the pre-updated setting ratio and the post-updated setting ratio is greater than a preset first ratio threshold (i.e., fine-tuning the second current ratio of the motion device); and generating a recommended update scheme when the number of first prompt signals generated within a first time period is greater than a preset first signal number, and forwarding the recommended update scheme to at least one of the control units through the main control module, wherein the recommended update scheme includes a suggested adjustment value for the setting ratio. For example, when multiple motion devices increase their setting ratios, the updated setting ratio used by each device is used as the suggested adjustment value.

[0130] In this embodiment, when multiple motion sensors are fine-tuning the magnitude of the second current, it is recommended to update or check the setting ratio of all motion sensors on the piano. This global early warning scheme based on the fine-tuning scenario of multiple motion sensors can avoid inaccurate playing caused by the piano deforming due to dry or humid environments, such as the inability to reproduce sustain effects.

[0131] For example, when a piano is exposed to a humid environment for a long time, the keys or hammers may become deformed and heavier due to moisture. In this case, the actuators may struggle to maintain the key pressure depth under the originally set second current, resulting in the inability to produce a sustain effect. To address this, local performance effects (i.e., fine-tuning of some actuators) can provide early warnings to the piano's overall drive system, adapting to changes in the piano under different environments or at different times (such as seasons).

[0132] In some embodiments, the method further includes the steps of: generating a second prompt signal when the difference between the set ratio before the update and the set ratio after the update is greater than a preset second ratio threshold; and generating a motion device detection signal when the number of second prompt signals generated within a first time period is less than a preset number of second signals, to prompt the user to detect the corresponding motion device. This is equivalent to sending a local warning signal to the user to prompt the user to pay attention to motion devices with large deviations.

[0133] Unlike the case where multiple actuators fine-tune the second current ratio, in this embodiment, when a local actuator exhibits a significant deviation in sustain effect, the user is prompted to focus on the actuator with the larger error for localized piano adjustments. In this invention, global and local warnings are provided for situations involving fine-tuning of multiple actuators and significant errors in a few actuators, respectively. This helps users initially determine the source of the error (such as environmental or climatic factors, or manufacturing defects in the actuators), thus assisting users in achieving efficient maintenance of the intelligent piano device.

[0134] In this regard, the driving method in this invention is beneficial for optimizing or maintaining the replication effect of the piano during long-term automatic playing.

[0135] In summary, this invention can help users quickly locate the root cause of problems by distinguishing between global fine-tuning and local deviations. For example, for environmental factors (such as humidity changes), the system can adjust the settings parameters of the exerciser globally; for hardware problems (such as defects in the exerciser's manufacturing process), targeted repairs or replacements can be made.

[0136] Furthermore, this invention solves the stability problem of intelligent pianos under complex working conditions through a hierarchical early warning mechanism (global / local) and environmental adaptive control, providing a reliable intelligent decision-making system for the precise maintenance of automated playing equipment.

[0137] Furthermore, the present invention also provides an adjustment mechanism for adaptively adjusting the degree of discreteness of discrete data, so as to alleviate or reduce the operational risks under multi-motor drive.

[0138] For example, in some embodiments, the present invention includes the steps of: (1) selecting a degree of dispersion based on the numerical characteristics of at least one segment of first external data, wherein the degree of dispersion is used to describe the time interval between discrete positions; wherein, the smaller the degree of dispersion, the higher the degree of music restoration produced under motor drive, that is, the more refined the restoration process. (2) converting the corresponding at least one segment of first external data according to the degree of dispersion to obtain corresponding discrete data; wherein the discrete data includes multiple discrete positions.

[0139] For example, in some embodiments, numerical features can be characterized by the degree of positional fluctuation. The smaller the degree of positional fluctuation, the larger the selected degree of dispersion. Conversely, the larger the degree of positional fluctuation, the smaller the selected degree of dispersion. In some embodiments, different recommended degrees of dispersion can be preset for different degrees of positional fluctuation. For example, the degree of positional fluctuation can be the rate of positional change, which can be obtained by differentiating the position-time curve.

[0140] Alternatively, the degree of positional fluctuation can be calculated as follows: calculate multiple differences between multiple sets of adjacent positions, calculate the average of these differences, and use this average as the degree of positional fluctuation. Alternatively, in some embodiments, numerical features can be characterized by the number of force nodes. External data collected from a single key can be categorized as a node. When a node reflects that the user's pressing force is greater than a preset force level, it can be identified as a force node. The more force nodes there are, the smaller the corresponding dispersion can be. For example, when the positional change rate under a node is greater than a set value, it is considered a force node.

[0141] For example, in some embodiments, all the first external data of the performance can be segmented, that is, different degrees of dispersion can be set according to the numerical characteristics of different segments. In this embodiment, different reproduction rules, or different degrees of reproduction, can be set for different types of piano music, or even different musical segments of the same piano music. The smaller the degree of dispersion, the higher the degree of reproduction.

[0142] For example, in some embodiments, different reproduction rules (specifically, the degree of dispersion) are selected based on the style of the musical score being performed. Specifically, a musical score can be divided into at least two sections, and a corresponding degree of dispersion can be selected based on the style (or type) of each section. In some embodiments, a recommended degree of dispersion is preset for a particular style / type.

[0143] For example, in some embodiments, a smaller degree of discretization can be recommended for styles such as romantic melodies, classical music (especially slow movements), and adagios, allowing the motion unit to accurately represent the simulated dynamics. This relatively accurate representation enhances the emotional impact of the automated performance (simulating the emotional effect conveyed by a live performance as closely as possible). Simultaneously, the relatively gentle rhythms of this type of music mean that even with higher precision dynamic simulation, the motor is less prone to overload issues. For example, in some embodiments, a larger degree of discretization can be recommended for styles such as allegro, rock, and virtuoso etudes. Furthermore, for these rhythmically strong music types, discretization largely preserves the rhythmic variations, allowing the user to still perceive the music's unique rhythm aurally. Increasing the degree of discretization also reduces the operating load on the motor.

[0144] Furthermore, the categorized and segmented reproduction rule adjustment mechanism proposed in this invention not only ensures a high degree of restoration accuracy but also significantly reduces motor power consumption during the restoration process. This control over motor power consumption is beneficial for the long-term stable operation of this multi-motor drive system (88 keys corresponding to 88 motors) (e.g., avoiding the risk of overheating and burnout) and also helps reduce the pressure on closed-loop control.

[0145] Alternatively, in some embodiments, the degree of discreteness can be preset by the user; for example, in some embodiments, the time interval between each discrete position is approximately 0.2ms-1.0ms. Preferably, in some embodiments, the time interval between each discrete position is preferably 0.2ms. In some embodiments, the piano includes at least two parallel main control modules, such as at least two primary main control modules.

[0146] In another aspect, the present invention provides a control system for automatic piano playing, wherein the piano includes multiple keys, and a motion device is disposed below each key. The motion device is connected to a control unit, and the output end of the motion device pushes the keys under the control of the control unit. The piano includes a main control module, and one main control module is connected to multiple control units. Correspondingly, referring to Figure 15, the system includes:

[0147] The acquisition module is used to acquire first external data generated corresponding to at least one key during the first performance time. The first external data is used to describe the position change of the key during the first performance time.

[0148] A discrete module is used to convert the first external data into discrete data, wherein the discrete data includes: multiple discrete locations, and the discrete locations are associated with time-series labels;

[0149] A sending module is used to send at least one of the discrete data to the main control module, and the main control module forwards the discrete data to the control unit of the motion device;

[0150] The monitoring module is used to monitor the second external data of the piano keys at a first moment, and find the corresponding discrete position based on the first moment through the time sequence label; the second external data is the position of the piano keys;

[0151] The closed-loop control module is used to calculate the difference between the second external data and the corresponding discrete position, and to use a closed-loop control algorithm to output the adjustment current value for the next time period based on the difference.

[0152] A drive module for the control unit to drive the motion device in response to the adjusted current value.

[0153] In some embodiments, the system further includes: a first judgment module, configured to determine whether the second external data is greater than or equal to a preset target position; a detection module, configured to identify the recording time corresponding to the second external data as a detection time if the result of the judgment module is yes; a second judgment module, configured to determine whether the detection time to the current time exceeds a preset time threshold; and a limiting module, configured to identify a first current at the current time if the result of the second judgment module is yes, and generate a second current based on the first current using a preset current limiting rule, wherein the magnitude of the second current is less than the first current, and input the second current into the control unit as a new adjustment current value.

[0154] In some embodiments, the method further includes: a rule update module, configured to monitor whether the difference between the second external data and the third external data collected in the next time period exceeds a preset position threshold; if so, to update the current limiting rule. Correspondingly, the drive system in this invention can execute the method or steps in any of the above embodiments:

[0155] As described above, the primary control module is connected to a data storage module, a data storage module, and a monitoring module;

[0156] Correspondingly, the data storage module is used to acquire first external data generated corresponding to at least one key during the first performance time, and the first external data is used to describe the position change of the key during the first performance time.

[0157] A data processing module is used to convert the first external data into discrete data, wherein the discrete data includes: multiple discrete locations, and the discrete locations are associated with time-series labels;

[0158] A sending module is used to send at least one of the discrete data to the main control module, and the main control module forwards the discrete data to the control unit of the motion device;

[0159] The monitoring module is used to monitor the second external data of the piano keys at a first moment, and find the corresponding discrete position based on the first moment through the time sequence label; the second external data is the position of the piano keys;

[0160] The closed-loop control module is used to calculate the difference between the second external data and the corresponding discrete position, and to use a closed-loop control algorithm to output the adjustment current value for the next time period based on the difference.

[0161] A drive module for the control unit to drive the motion device in response to the adjusted current value.

[0162] Example 3: It is worth noting that, in addition to the exemplary motion device given above, the present invention also provides another exemplary motion device solution, as shown in Figures 16-23. The present invention uses another set of reference numerals to explain and describe this motion device (also referred to as: driving device):

[0163] Referring to Figures 16-23, the present invention provides a driving device with a double-coil electromagnet and an automatic piano playing device.

[0164] This invention provides a driving device with a dual-coil electromagnet, as shown in Figure 16. The driving device includes a driving assembly and an auxiliary assembly spaced apart. The driving assembly includes a first iron core 1A and a first coil module disposed outside the first iron core 1A. The first coil module includes a first support member 12A, a first coil group 11A disposed around the first support member 12A, and a first sleeve 13A sleeved on the first coil group and the first support member. The auxiliary assembly includes a second iron core 2A and a second coil module disposed outside the second iron core 2A. The second coil module includes a second support member 22A and a first coil group 11A disposed around the second support member 22A. The device includes a second coil group 21A and a second sleeve 23A fitted onto the second coil group and the second support member; the first iron core 1A is connected to the second iron core 2A through a connecting part 10A, and the length L1A of the first iron core is greater than the length L2A of the second iron core, and the length L3A of the first coil group is greater than the length L4A of the second coil group; the driving device also includes a buffer module, which includes a first buffer element 3A (or a first buffer component) and a second buffer element 4A (or a second buffer component), the first buffer element 3A is connected to the first iron core 1A through a top rod 14A, and the second buffer element 4A is connected to the first buffer element 3A.

[0165] In some embodiments, the first coil group or the second coil group is formed by winding wires on the first support or the second support.

[0166] In this embodiment, the term "length" refers to the length along the axial direction of the first or second iron core. For example, the length L3A of the first coil group or the length L4A of the second coil group refers to the length of the winding area of ​​the coil group along the axial direction of the first or second iron core, rather than the length of the conductor itself.

[0167] In some embodiments, the first coil group 11A and the second coil group 21A are respectively connected to a power supply for supplying them. When the first coil group is energized, the magnetic field generated by the first coil group can drive the first iron core 1A to move in the first thread (i.e., the long thread); when the second coil group is energized, the magnetic field generated by the second coil group can drive the second iron core 2A to move in the second thread (i.e., the short thread), and the first thread is longer than the second thread.

[0168] In other words, this solution uses the first iron core and the second iron core to drive the first thread and the second thread (i.e., dual threads) to rise and fall respectively. With the combined effect of long and short threads, it achieves the effect of effectively controlling the piano's sound production.

[0169] Furthermore, in some embodiments, the second thread is X2 (as shown in Figure 19), and X2 ≤ 2mm. Furthermore, in some embodiments, the distance between the first threads is no more than 4mm.

[0170] In some embodiments, an isolation portion 15A is provided between the first sleeve 13A and the second sleeve 23A. For example, the first surface of the isolation portion is connected to the first sleeve, and the second surface of the isolation portion is connected to the second sleeve. The interior of the isolation portion is provided with a space for the first iron core 1A and the second iron core 2A to reciprocate.

[0171] In some embodiments, the insulating portion is made of a non-ferromagnetic material. In some embodiments, the top rod 14A is made of a material with sufficient strength, such as metal. In some embodiments, the first support member 12A and the second support member 22A are made of plastic.

[0172] In some embodiments, the length L4A of the second coil group 21A is 4-20 mm. Preferably, in some embodiments, L4A is 6.4 mm. In some embodiments, the number of turns N2 of the second coil group 21A is 100≤N2≤2000. In some embodiments, the length of the second iron core 2A is 13 mm. In some embodiments, the length of the second support member 22A is 0.8 mm. In some embodiments, the length of the second sleeve 23A is 12 mm.

[0173] In some embodiments, the distance between the first sleeve 13A and the second sleeve 23A is L5A (as shown in Figure 17), the length of the connecting part 10A is L6A (as shown in Figure 17), the maximum distance of the first thread is X1 (as shown in Figure 20), and the length by which the first iron core 1A extends beyond the first sleeve 13A is H1A (as shown in Figure 21), that is, the difference H1A between the lengths of the first iron core and the first sleeve. L5A, L6A, X1, and H1A satisfy the following relationship: L5A = L6A + X1 + H1A. In other embodiments, L5A is 9mm, L6A is 3mm, X1 is 4mm, and H1A is 2mm. Specifically, the length relationship between L6A and L5A can be adjusted according to actual conditions.

[0174] In some embodiments, the connecting portion 10A is made of a non-ferromagnetic material. In some embodiments, both the first and second buffer members are made of flexible materials. Further, in some embodiments, the first buffer member is a pad, and its material can be a soft material such as wool felt, foam, or silicone. In other embodiments, the second buffer member is a cap, and its material can also be a soft material such as silicone, rubber, or foam.

[0175] In some embodiments, a shell is fitted onto the first iron core 1A and the second iron core 2A. Further, in some embodiments, the shell is made of a non-ferromagnetic material, such as copper, titanium alloy, or stainless steel, which has low magnetic permeability, to increase the strength of the first and second iron cores. In some embodiments, the first sleeve 13A and the second sleeve 23A are made of iron.

[0176] In some embodiments, the first sleeve 13A includes a first upper top plate 130A, a first lower bottom plate 131A, and a first side plate 132A connected to each other. The first upper top plate 130A and the first lower bottom plate 131A are formed by extending outwards from both ends of the first side plate 132A, thereby forming a protective enclosure for the first coil assembly 11A. In some embodiments, the length of the first upper top plate and the length of the first lower bottom plate are the same.

[0177] In some embodiments, the second sleeve 23A includes a second upper top plate 230A, a second lower bottom plate 231A, and a second side plate 232A connected to each other. In some embodiments, the length of both the second upper top plate and the second lower bottom plate is 2 mm. Similarly, the second upper top plate 230A and the second lower bottom plate 231A are formed by extending outward from both ends of the second side plate 232A, thereby forming a protective enclosure for the second coil assembly.

[0178] The operating mode of the driving device of the present invention is as follows:

[0179] Rising process: When the first coil group is energized and the second coil group is de-energized, the first coil group will generate an attractive force on the first iron core. The electromagnetic field generated by this force causes the first iron core to experience a first upward force, which drives the first iron core to gradually rise along with the second iron core. This causes the first and second iron cores to gradually rise from the first position (as shown in Figure 19(a)) to the second position (as shown in Figure 19(b)), and finally stop at the third position (as shown in Figure 19(c)).

[0180] The descent process: When the first coil group is de-energized and the second coil group is energized, the second coil group will generate an attractive force on the second iron core. The electromagnetic field generated by this force causes the second iron core to experience a second upward force. The second upward force is in the same direction as the first upward force, and the second upward force is less than the first upward force, thus controlling the second iron core to gradually lower the first iron core. This means that the first and second iron cores begin to fall slowly from the third position, and eventually the second iron core is attracted and suspended by the second coil group, while the first and second iron cores stop at the second position.

[0181] From another perspective, the present invention actually provides a dual-threaded driving device, which includes a driving component and an auxiliary component spaced apart. The driving component includes a first magnetic part and a first coil module disposed outside the first magnetic part. The first coil module includes a first support member, a first support member 12A, and a first coil group 11A disposed around the first support member 12A. The first coil module may further include a first sleeve 13A disposed outside the first coil group and the first support member.

[0182] The auxiliary component includes a second magnetic part (such as a second iron core 2A) and a second coil module disposed outside the second magnetic part. The second coil module includes a second support member 22A and a second coil group 21A disposed around the second support member 22A. The second coil module may further include a second sleeve 23A disposed outside the second coil group and the second support member. The first magnetic part and the second magnetic part are connected by a connecting part 10A.

[0183] The length of the first magnetic part is greater than the length of the second magnetic part. The length L3A of the first coil group is also preferably greater than the length L4A of the second coil group. The driving device further includes a buffer module, which is disposed at the output end of the first magnetic part (i.e., the end facing the piano keys). Specifically, the buffer module is connected to the first magnetic part via a push rod 14A.

[0184] In some embodiments, the magnetic part (such as the first magnetic part or the second magnetic part) may be inherently magnetic (such as a permanent magnet material, such as iron), or may generate induced magnetism under an electromagnetic field (such as a soft magnetic material with high permeability), thereby acting as a mover in the motor to achieve continuous and controllable mechanical motion.

[0185] In the driving device of the present invention, the current applied to the second coil group is reduced in the second thread of the second iron core, and the positions of the first iron core and the second iron core will change accordingly and hover.

[0186] This invention is based on a two-way control, separate master-slave drive design. Specifically, the drive assembly controls the rising process of the iron cores (referring to the first and second iron cores), primarily by energizing the first coil group to drive the first iron core, which in turn drives the second iron core to rise. The auxiliary assembly mainly assists in driving the iron cores' falling process, primarily by energizing the second coil group to drive the second iron core, which in turn drives the first iron core to fall. Therefore, under this specific operating mode, effective control of the iron core's movement process can be achieved.

[0187] Specifically, regarding the design of the damping process of the piano's damping material, this solution incorporates auxiliary components to enable the drive device to produce smoother sounds and improve performance quality during automatic piano playing. Specifically, this auxiliary design achieves precise control of the second thread of the second coil group, allowing for more flexible control of the damping material's return process, thus effectively controlling the damping process. Controlling the damping process results in a smoother piano sound, producing reverberation or special timbres, enriching the techniques of automatic piano playing.

[0188] The implementation of the specific master-slave drive method in this scheme is also related to the spacing between the drive components and auxiliary components, as well as the specific lengths or distances between the first coil group, the second coil group, the first iron core, and the second iron core. These can be adaptively adjusted by technicians according to actual needs. This allows the first iron core to drive the second iron core upwards when the first coil group is energized, with the interaction between the iron cores having almost no impact on the upward movement. Similarly, when the second coil group is energized, the second iron core drives the first iron core downwards, with the interaction between the iron cores having almost no impact on the downward movement.

[0189] The present invention also provides an automatic piano playing device, the device including the aforementioned driving device, the piano including keys, and the driving device being connected to the end of the keys via the second buffer 4A. In other embodiments, the driving device is connected to the hand-pressing end of the keys via the second buffer 4A.

[0190] In some embodiments, the automatic piano playing device operates as follows: Key pressing process: When the first coil group is energized and the second coil group is de-energized, the first coil group attracts the first iron core, and the resulting electromagnetic field causes the first iron core to experience a first thrust, driving the first iron core to gradually rise along with the second iron core and the push rod. Finally, the iron core stops at the first playing position where the push rod can press the key, at which point the strings can be struck to produce sound.

[0191] Mute process: When the first coil group is de-energized and the second coil group is energized, the second coil group will generate an attractive force on the second iron core. The electromagnetic field generated by this force causes the second iron core to experience a second thrust. The first and second thrusts are in the same direction, and the second thrust is less than the first thrust, thus controlling the second iron core to gradually lower the first iron core and the push rod. This allows the first and second iron cores to slowly fall from the first playing position, until the second iron core is finally attracted and suspended by the second coil group, stopping the first and second iron cores at the first return position. At this time, the piano's damping cotton applies a certain pressure to the strings, ensuring that the strings do not completely stop vibrating and can still produce sound.

[0192] In other words, in this embodiment, the directions of both the first and second thrusts are opposite to the direction of gravity of the iron cores (first and second iron cores), which can overcome the gravity of the iron cores and better control their movement. The magnitude of the second thrust is less than one-tenth of the first thrust, allowing the iron cores to slowly fall back, thus effectively controlling the timing and force of the damping. In other words, this solution can achieve simple and precise control over the damping process of the damping cotton, greatly improving the quality of the player piano's performance and the fidelity of its repetitions.

[0193] Furthermore, within the second thread of the second iron core described in this device, during the process of the second iron core driving the first iron core and the push rod to gradually fall by about 2mm, the damping cotton can change from a state of being detached from the strings to a state of contact, and the pressure gradually increases. Finally, the strings are completely pressed down by the damping cotton, stopping the vibration, at which point the piano stops playing. Simultaneously, the area within the second thread of the second iron core is also the key area for the keys to fall back down.

[0194] In some embodiments, when the first coil group is energized, the simulation diagram of the magnetic field lines of the first and second iron cores during the rising process is shown in Figure 22. When the first iron core approaches the first upper plate to form a closed loop, the magnetic field lines are denser and the attraction is greater. Furthermore, the greater the vertical component of the magnetic field lines, the greater the attraction. As the first iron core rises from its position near the first upper plate to above it, the vertical component of the magnetic field lines decreases, and the force also decreases.

[0195] In other embodiments, referring to Figure 23, a simulation diagram of the magnetic field lines of the first and second iron cores during the fall-back and slow descent processes is shown when the second coil group is energized.

[0196] Referring to Figures 22 and 23, the importance of the positional relationship between the separate master-slave drive (drive component and auxiliary component) in this design is verified. When L5A = L6A + X1 + H1A is satisfied, the drive component and auxiliary component can work together to effectively control different stages of piano playing (key pressing and muting processes) during actual use, thereby making the piano sound more continuous and smooth during performance and improving the musical quality of automatic piano playing.

[0197] In summary, this invention provides a separate master-slave drive scheme based on two-way control, and designs a drive device with a dual-coil electromagnet and an automatic piano playing device based on this scheme. By using a separate master-slave drive design for the drive component and the auxiliary component, precise control (i.e., two-way control) of the movement distance of the first and second threads of the iron core is achieved, thereby effectively coordinating the control of the piano's sound production. Specifically, for the piano's sound production process, a long-short co-driving dual-thread control mode is set up. The first coil group in the drive component primarily drives the first iron core to control the rising distance (i.e., control of the first thread), and the second coil group in the auxiliary component assists in driving the second iron core to control the falling distance (i.e., control of the second thread). In other words, this scheme precisely controls the first and second threads through a separate co-driving dual coil group and a co-driving iron core. The first thread (long thread) controls the key pressing process, and the second thread (short thread) controls the muting process. The combination of long and short threads allows the piano to produce a smoother sound. This invention uses a simple structural design to control the sound production and muting during the automatic playing process of a piano, thereby making the music played more fluid and harmonious.

[0198] In summary, the motion device proposed in this invention avoids the mechanical feel that easily occurs in automatic piano playing applications, where the sound abruptly stops and the sound quality is poor once the key touch is stopped. Instead, this invention effectively controls the damping process of the piano's damping cotton, making the piano's sound production no longer monotonous but continuous. Therefore, it can simulate human playing techniques as closely as possible, producing music with rich tones, improving the quality of automatic playing, and enhancing the fidelity of repeated performances.

[0199] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications are within the protection scope of the present invention.

Claims

1. A drive system for automatic piano playing, characterized in that, The drive system adopts a non-destructive built-in drive module, wherein the piano includes: a sound module, the sound module includes: a linkage (03) and a hammer (04) connected to the linkage (03); piano keys (01), and a push rod (02) is provided at the rear end of the piano keys (01); The driving module includes: a motion device (05), which is disposed at the rear end of the piano key (01) and has an output terminal disposed opposite to the rear end of the piano key (01); wherein, the motion device includes: The moving part assembly includes: a permanent magnet (1), wherein a first metal segment (11a) and a second metal segment (11b) are respectively provided at the first end and the second end of the permanent magnet (1); A stator assembly comprising: a conduit (2) disposed on the outer periphery of the permanent magnet (1), wherein at least two sets of coils are wound in the reverse direction, the at least two sets of coils comprising a first set of coils (30) and a second set of coils (31), the first set of coils (30) being wound around the conduit in a first winding direction, and the second set of coils (31) being wound around the conduit in a second winding direction; the input end of the first set of coils being connected to a first pole of a power supply, the output end of the second set of coils being connected to a second pole of the power supply, the output end of the first set of coils being connected to the input end of the second set of coils, and the first winding direction being opposite to the second winding direction; Furthermore, the axial length of the moving part assembly is less than the axial length of the at least two sets of coils.

2. The drive system according to claim 1, characterized in that, The axial length of the first metal segment (11a) is greater than the axial length of the second metal segment (11b).

3. The drive system according to claim 2, characterized in that, The material of the first metal segment or the second metal segment is iron.

4. The drive system according to claim 1, characterized in that, The axial length of the moving part assembly is greater than the axial length of the first group of coils or the second group of coils, so that the two ends of the moving part assembly are located in different coil regions.

5. The drive system according to claim 1, characterized in that, The actuator further includes a control unit for controlling the input current of the coil to control the movement of the actuator assembly.

6. The drive system according to claim 5, characterized in that, The drive system further includes: at least two primary main control modules, one of which is connected to the control unit; and a secondary main control module, which is connected to the primary main control module.

7. The drive system according to claim 6, characterized in that, The primary control module also includes or is connected to a data storage module, which is used to store first external data of at least one piano key, the first external data being the historical motion data of the piano key. And / or, further includes: a position monitor for monitoring the position of the piano keys.

8. The drive system according to claim 7, characterized in that, The primary control module is connected to a data storage module, a data processing module, and a monitoring module; correspondingly, the drive system includes: Data storage module is used to acquire first external data generated corresponding to at least one key during the first performance time, the first external data being used to describe the position change of the key during the first performance time; A data processing module is used to convert the first external data into discrete data, wherein the discrete data includes: multiple discrete locations, and the discrete locations are associated with time-series labels; A sending module is used to send at least one of the discrete data to the main control module, and the main control module forwards the discrete data to the control unit of the motion device; The monitoring module is used to monitor the second external data of the piano keys at a first moment, and find the corresponding discrete position based on the first moment through the time sequence label; the second external data is the position of the piano keys; The closed-loop control module is used to calculate the difference between the second external data and the corresponding discrete position, and to use a closed-loop control algorithm to output the adjustment current value for the next time period based on the difference. A drive module for the control unit to drive the motion device in response to the adjusted current value.

9. The drive system according to any one of claims 1-8, characterized in that, Also includes: Sleeve (4), the sleeve (4) is disposed on the outside of the coil; And / or, the output end includes: a connecting rod (10) extending along the moving part assembly, the connecting rod (10) having a buffer module at the end corresponding to the piano key.

10. A piano, characterized in that, The piano is equipped with a drive system as described in any one of claims 1-8.

11. A control method for automatic piano playing, characterized in that, The piano includes multiple keys, and a actuator is disposed below each key. The actuator is connected to a control unit, and the output of the actuator pushes the keys under the control of the control unit. The piano includes a main control module, and one main control module is connected to multiple control units. Correspondingly, the method includes: S101, acquire first external data corresponding to at least one key during the first performance time, the first external data being used to describe the position change of the key during the first performance time; S102, the first external data is converted into discrete data, and the discrete data includes: multiple discrete locations, the discrete locations being associated with time-series labels; S103, at least one of the discrete data is sent to the main control module, and the main control module forwards the discrete data to the control unit; S104, monitor the second external data of the piano key at the first moment, and find the corresponding discrete position based on the first moment through the time sequence label; the second external data is the position of the piano key; S105, calculate the difference between the second external data and the corresponding discrete position, and use a closed-loop control algorithm to output the adjustment current value for the next time period through the difference; S106, the control unit drives the motion device in response to the adjusted current value.

12. The method according to claim 11, characterized in that, Also includes: S107, determine whether the second external data is greater than or equal to the preset target position; S108, if the result of S107 is yes, then the recording time corresponding to the second external data is identified as the detection time; S109, determine whether the time from the detection time to the current time exceeds a preset time threshold; S110, if the result of S109 is yes, then identify the first current at the current moment, and generate a second current based on the first current using a preset current limiting rule, wherein the magnitude of the second current is less than the first current, and input the second current into the control unit as a new adjustment current value.

13. The method according to claim 12, characterized in that, The method further includes: Monitor whether the difference between the second external data and the third external data collected in the next time period exceeds a preset location threshold; If so, the current limiting rule is updated.

14. The method according to claim 13, characterized in that, The current limiting rule is that the second current = the first current × a set ratio; correspondingly, the step of updating the current limiting rule includes increasing or decreasing the set ratio.

15. The method according to claim 14, characterized in that, It also includes the following steps: When the difference between the setting ratio before the update and the setting ratio after the update is greater than the preset first ratio threshold, a first prompt signal is generated; When the number of first prompt signals generated in the first time period is greater than the preset number of first signals, a recommended update scheme is generated, and the recommended update scheme is forwarded to at least one of the control units through the main control module. The recommended update scheme includes: the suggested adjustment value of the set ratio.

16. The method according to claim 14 or 15, characterized in that, It also includes the following steps: When the difference between the setting ratio before the update and the setting ratio after the update is greater than the preset second ratio threshold, a second prompt signal is generated; If the number of second prompt signals generated in the first time period is less than the preset number of second signals, a motion detection signal is generated to prompt the user to detect the corresponding motion device.

17. The method according to claim 11, characterized in that, The piano includes at least two parallel master control modules.

18. A control system for automatic piano playing, characterized in that, The piano includes multiple keys, and a actuator is disposed below each key. The actuator is connected to a control unit, and the output of the actuator pushes the keys under the control of the control unit. The piano includes a main control module, and one main control module is connected to multiple control units. Correspondingly, the system includes: Data storage module is used to acquire first external data generated corresponding to at least one key during the first performance time, the first external data being used to describe the position change of the key during the first performance time; A data processing module is used to convert the first external data into discrete data, wherein the discrete data includes: multiple discrete locations, and the discrete locations are associated with time-series labels; A sending module is used to send at least one of the discrete data to the main control module, and the main control module forwards the discrete data to the control unit of the motion device; The monitoring module is used to monitor the second external data of the piano keys at a first moment, and find the corresponding discrete position based on the first moment through the time sequence label; the second external data is the position of the piano keys; The closed-loop control module is used to calculate the difference between the second external data and the corresponding discrete position, and to use a closed-loop control algorithm to output the adjustment current value for the next time period based on the difference. A drive module for the control unit to drive the motion device in response to the adjusted current value.

19. The system according to claim 18, characterized in that, Also includes: The first judgment module is used to determine whether the second external data is greater than or equal to the preset target position; The detection module is used to identify the recording time corresponding to the second external data as the detection time if the result of the judgment module is yes; The second judgment module is used to determine whether the time from the detection time to the current time exceeds a preset time threshold. If the result of the second judgment module is yes, the limiting module identifies the first current at the current moment, generates a second current based on the first current using a preset current limiting rule, and the magnitude of the second current is less than the first current. The second current is then input into the control unit as a new adjustment current value.

20. The system according to claim 19, characterized in that, The system also includes: The rule update module is used to monitor whether the difference between the second external data and the third external data collected in the next time period exceeds a preset position threshold; if so, the current limiting rule is updated.

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