Device for generating a haptic simulation of a musical instrument

Abstract

The invention relates to a haptic device (1) for controlling a key of a keyboard with which an electronic musical instrument is equipped, said device being associated with a key (K) mounted so as to be able to pivot with respect to a frame, the key extending in a longitudinal direction and having an angular movement between a high angular position, and a low angular position, characterized in that said device comprises: - means (30) for detecting the dynamic state of the key, - computing means for computing, depending on the dynamic information, an instantaneous resistive force to be exerted on said key in response to a depression of said key, - a rotary electrical actuator (10), - mechanical linking means (20) placed between the actuator and the key so as to apply, to said key, said resistive force, comprising at least one element that flexes under pressure and stiffens under traction.

Description

DOMAINE TECHNIQUE DE L'INVENTION

[0001] The present invention relates to haptic simulation or emulation devices for digital keyboard musical instruments.

[0002] The invention relates more particularly to a device reproducing the haptic sensation of the keyboards of an acoustic piano by an electronic piano and its associated method. ÉTAT DE LA TECHNIQUE

[0003] For many years, designers and manufacturers of electronic pianos have strived to improve the touch sensation, bringing it closer to that of an acoustic piano by providing a haptic effect that closely resembles the original. At the level of the electronic piano's keyboard, this involves reproducing the "force feedback" exerted by the components (bridge, stick, lever, hammer, damper) of the acoustic piano's key mechanism.

[0004] Traditional acoustic pianos are designed with a certain resistance to touch and a specific key return speed to ensure proper operation and provide the pianist with a good playing feel. Tuning a piano's keyboard involves adjusting the downward and upward weights of the keys, sometimes using weights to fine-tune these values. The balance of the touch also depends on the inertia of the action. This inertia is a function of the mass of the components, primarily the hammers and key weights, as well as the action levers. More specifically, inertia can be defined as the mechanical ratio between the hammer travel and the key travel.Finally, numerous other effects, non-linear and sometimes irregular (in the mathematical sense), also influence the quality of the touch: the stiffness of the felt connecting the parts, internal friction within the felts, and dry friction at the contacts and along the axes of rotation. Ultimately, the relationship between the key's "force feedback" and its movement results from a multi-degree-of-freedom dynamic that is non-linear, irregular, and dependent on the movement history. It cannot be accurately described by an impedance-type relationship.

[0005] As early as 1928, on instruments of the Ondes Martenot type, a key, called the "intensity key" or expression key, was already present, allowing control of the volume of the sound produced by the instrument. The key was mounted as a lever so that pressing it caused a bag of conductive powder to be crushed, which transmitted the electrical signal carrying the sound. Crushing the bag altered the resistivity of the powder and, consequently, the amplitude of the sound. The use of such a bag allowed for a relationship between the force applied to the key and the amplitude of the sound that closely approximated the psychophysiological perception of the musician.

[0006] US9275618 adopts this principle and improves upon it. The key's stem is attached to a flexible metal blade at its end, which is sandwiched between the blades to allow the key to pivot. A force and / or position sensor is located on the key. A deformable stop (made of elastomer) located under the key's stem exerts a force that resists downward movement by the user. An asymmetrical bore in this stop ensures that the resistive force applied by the stop is non-linear and monotonic. The sensor receives information about the resistive force resulting from the action of the flexible blade and the deformable stop as a signal, which is then sent to a processing unit to generate a sound with a volume corresponding to the stimulus.

[0007] US patent 4,899,631A discloses an electronic musical keyboard featuring a dynamic touch simulator consisting of a cable connected to the key and controlled by a DC motor. An electronic digital module simulates the key force feedback based on dynamically connected parameters.

[0008] French patent application FR2902538 describes a haptic simulation device using a magnetorheological fluid whose viscosity is modulated by a magnetic field to generate a force that opposes the movement of the key in order to improve the musician's tactile experience. The keyboard instrument disclosed in this document uses three sensors (acceleration, velocity, and position) positioned to provide real-time current control to the magnetic field generation means. This time-dependent control exerts a reaction force proportional to the key's movement, thus providing a satisfactory tactile sensation. The generation means consist of a coil carrying a time-varying current, which allows for the application of a force of varying intensity to a blade attached to the key, depending on the current value.

[0009] Document WO2020 / 016536 describes a haptic controller capable of reproducing certain sounds other than those of a traditional piano. One of these features is commonly referred to as "aftertouch," and its essential element is a damping device consisting of a body made of a deformable material with two recesses. This body has a protrusion positioned in a groove on the underside of a key. The two recesses absorb the compression exerted by the key via the protrusion, providing two different damping profiles: one soft, the other rigid. Sensors adapted to measure the rotational and translational movement of the keys output a signal based on this movement.

[0010] Patent US7582821 discloses a device designed to replicate the feel of a key release on an acoustic piano. It consists primarily of a pivoting lever, three key switches, and a retractable load member. When the musician presses a key, it pivots around its axis and presses against the pivoting lever, which is approximately the same length as the key and positioned beneath it. The pivoting lever, in turn, contacts three elastic switches of varying lengths. These switches provide information about the depth of the key press through the sequential activation of the switches. The retractable load member slows the lever's upward movement based on information gathered by the switches and position sensors.

[0011] In document US2018286605, the reactive force generation device consists of a deformable element in the shape of an inclined dome having at the top a flat surface whose inclination allows the key that exerts pressure to be received stably.

[0012] Finally, in the document "Implementation of a Force Feedback Device to Simulate the Touch of Various Piano Strike Mechanisms," Guillaume Paillot and Quentin Desclée (2018) propose a force feedback device consisting of an actuator located at the key pilot (the contact area between the key and the strike mechanism) and composed of two fixed permanent magnets and a coil attached to the key. This design presents a stability problem due to its mass and the inertia conferred by this arrangement, which are greater than that of a traditional key.

[0013] However, these devices are bulky for the available space and / or expensive and / or do not allow sufficiently to reproduce the dynamics of a given key (for example of acoustic piano) in an active way, without using the mechanism that originates this dynamic, which is even more expensive, or a derivative mechanism, which is unsatisfactory in terms of user control of the musical instrument. SUBJECT OF THE INVENTION

[0014] To this end, and according to a first aspect, the invention proposes a haptic control device for a key on a keyboard of an electronic musical instrument, designed to reproduce the feel of playing a similar acoustic musical instrument. This device is arranged to be associated with a key of the electronic musical instrument, which is pivotally mounted on a frame around a pivot axis. The key extends in a longitudinal direction and has an angular range of motion between a high angular position, referred to as the origin, and a low angular position, referred to as the stop. The device comprises: detection means arranged on the key to detect information about the dynamic state of the key, calculation means to calculate, based on the dynamic information thus detected, an instantaneous resistive force to be exerted on said key in response to a pressing of said key, a rotary electric actuator arranged to produce the resistive force, mechanical linkage means arranged between the rotary electric actuator and the key to apply said resistive force to said key, said mechanical linkage means comprising at least one element flexible in pressure and rigid in tension.

[0015] The device according to the invention makes it possible to reproduce the feel of playing an acoustic musical instrument, for example a piano, while offering a compact, inexpensive design with little or no inertia in its operation and little or no instability in its control. It allows the user to select or set a predetermined resistance to key depressment. Furthermore, it allows the user to apply a dynamic opposing force to the key depressment, according to a predetermined dynamic relationship, including one involving several internal degrees of freedom. Finally, it tends to return the key to its original position when the user releases its pressure.

[0016] For the purposes of the preceding and / or subsequent descriptions, the following terms are used: by key, a manual control device arranged to control the emission of a sound when pressed by a musician; by rotary electric actuator, a rotating electromagnetic device or actuator; by distal end of the key, the contact area or end area intended to receive the user's finger(s); by proximal end, the end of the key opposite the distal end; by key return, a part projecting from the underside of the key such that one face of said key return is opposite the underside of the key, for example, the key return is L-shaped, with one face of the base of the L-shaped key return opposite the underside of the key; by mechanical linkage means, means connecting the actuator to the key,said means may comprise one or more mechanical elements connected together, by a flexible element in one direction of the mechanical linking means, means capable of flexing without exhibiting longitudinal elasticity, and / or limited flexibility (generally a wire has very high flexibility) and especially one-dimensional or unidirectional: zero flexibility in two directions of stress, by a flexible element in compression and rigid in tension, a flexible element arranged to work in tension both to convert the resisting mechanical torque into a resisting force applied at a point of said key during depressment, and to return said key to its angular rest position, by termination, an end of the mechanical linking means, such as an actuator termination or a key termination, and / or an end of a flexible element, for example a cable termination or a ribbon termination,by high angular position, or home position, the position in which the key is at its upper limit before a user begins to press it to produce a sound during normal instrumental playing; by ribbon, an element having a width at least three times greater than its thickness, for example a thin sheet of metal or fibrous polymer or composite material, capable of flexing without exhibiting longitudinal or transverse elasticity other than that allowing bending or curvature, and exhibiting low but non-negligible resistance to bending or coiling; by cable, a cable or the parallel combination of several cables (for example, between 2 and 5 cables) capable of flexing in two directions but which do not exhibit longitudinal elasticity.

[0017] Preferably, the pivot axis of the key is located at a proximal end of said key.

[0018] Preferably, the mechanical linkage means are arranged between the actuator and the key. The mechanical linkage means include an actuator end and a key end. In one embodiment, the mechanical linkage means comprise a single key end and a single actuator end.

[0019] Preferably, the key termination is fixed to the key at a contact point, called the fixing point, located between, on the one hand, a receiving point situated at a distance at least equal to 25% of the longitudinal length of said key from the pivot axis and, on the other hand, the distal end of the key. In other words, the contact point may be located on a continuous area extending over a distance equal to 75% of the longitudinal length of said key from its distal end.

[0020] The function of the actuator and the mechanical linkage between said actuator and the key is to physically exert a force on the key, the force being prescribed or having a predetermined relationship to the key's movement. Depending on the point of attachment on the key, the torque exerted by the actuator on the key is, at most, the product of approximately twenty newtons and the lever arm of the distal end, in fortissimo mode.

[0021] According to a first embodiment, the rotary electric actuator has an axis of rotation parallel to the pivot axis of the key.

[0022] According to a second embodiment, the rotary electric actuator has an axis of rotation parallel to the longitudinal direction of the key.

[0023] According to a third embodiment, the rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the axis of rotation of the key.

[0024] The position in which the actuator's axis of rotation is parallel or perpendicular to the key's longitudinal direction refers to the position established when the key is at rest or in its original position. The key may rotate a few degrees when pressed by a user. In other words, the actuator's axis of rotation and the key's longitudinal direction are substantially parallel or substantially perpendicular, within a few degrees, and lie in the same vertical plane.

[0025] Preferably, the rotary electric actuator is a DC electric motor.

[0026] Advantageously, the rotary electric actuator is positioned above or below the key. The arrangement of the actuator and the mechanical linkage means is designed to exert traction on the instrument's key, so as to provide resistance to depressment when the user presses said key and to return the key to its original position when the user does not press said key.

[0027] Advantageously, the mechanical connecting means are located above or below the key. Preferably, the mechanical connecting means include a key termination of the mechanical connecting means which is fixed to an upper or lower face of the key.

[0028] The upper surface is defined as a surface facing upwards when the electronic musical instrument is positioned horizontally, and / or a surface facing outwards from the instrument. The lower surface is defined as a surface facing downwards when the electronic musical instrument is positioned horizontally, and / or a surface facing inwards from the instrument.

[0029] The mechanical linkage means include means for connecting to the key. The linkage means are fixed to the key and are arranged to connect the key termination of the mechanical linkage means to the key.

[0030] The mechanical connection means include at least one connecting piece corresponding to the key termination. Preferably, the connecting piece is placed as far as possible from the key's pivot axis. This distance allows for a greater resistive torque to be applied to the key and / or for the selection of an actuator from a range of devices with a lower current rating or lower power, thus reducing the price and / or inertia of the motor, and / or the cost of its electrical control.

[0031] For example, the ratio between the lever arm distance separating the pivot axis from the contact point where the contact termination of the mechanical linkage means is fixed to the contact, on the one hand, and the lever arm distance separating the rotation axis of the rotary electric actuator from an actuator point where the actuator termination of the mechanical linkage means is fixed to the actuator shaft, on the other hand, is at least 10, preferably at least 20, advantageously at least 30, advantageously at least 40, advantageously at least 50.

[0032] According to one embodiment, the rotary electric actuator is located below the key, for example above the key return, said key return being fixed to or arranged on the underside of the key, for example in a flat piano.

[0033] Preferably, the key termination of the mechanical linkage means is fixed to an upper face of a key return. The mechanical linkage means include a connecting piece disposed on an upper face of the key return.

[0034] Advantageously, the rotary electric actuator has a diameter or width smaller than the average width of a key. Preferably, the rotary electric actuator has a diameter or width less than twice the average width of a key.

[0035] It can also have a longitudinally elongated shape, thereby increasing the length of the electrical conductors and thus the torque available for a given current in the actuator.

[0036] According to one embodiment, the mechanical linkage means include assembly means comprising a winding piece arranged to fit onto the shaft of the rotary electric actuator, and a clamping piece in the shape of a stirrup having two arms arranged to at least partially surround the winding piece.

[0037] Preferably, at least one flexible element is flexible in only one direction. For example, the at least one flexible element in only one direction comprises one or more ribbons or one or more cables.

[0038] Firstly, the slight bending of the flexible element in a single direction serves to ensure, at least partially, the kinematic compatibility between the key's rotational movement and the translational movement imposed by the actuator's pull. The flexibility of this element allows it to wrap around the actuator's axis. In cases where the mechanical linkage comprises two elements flexible in a single direction, in particular two ribbons, the kinematic compatibility between the key's rotational movement and the actuator is achieved by one ribbon, called the key ribbon, and the wrapping around the actuator's axis is achieved by a ribbon, called the actuator ribbon, which is separate from the key ribbon, the two ribbons being connected to each other.

[0039] Secondly, reduced flexibility (not infinite, as is practically the case with a wire) prevents the actuator from continuing to rotate when the key is blocked or its movement is slowed, for example by the lower stop. The number and duration of rebounds are limited by the very specific behavior of the longitudinal compressibility of a flexible element along a given direction: zero up to the buckling limit, then finite beyond the buckling limit.

[0040] Preferably, the mechanical linkage means comprise at least one ribbon, or at least one cable, flexible in pressure and rigid in tension, having a distal termination connected to a hub of the rotary electric actuator and a proximal termination connected to the key, said ribbon being arranged to work in tension at the same time: (i) to convert the resisting mechanical torque into a resisting force applied at a point of said key being pressed and (ii) to return said key to its resting angular position.

[0041] The at least one ribbon provides the necessary traction to activate the key while allowing a slight flex to ensure compatibility between the key's rotational movement and the ribbon's translational movement when pulled by the actuator. Furthermore, the ribbon's inherent flexibility prevents or dissipates rebound vibrations when the key reaches the end of its travel.

[0042] Preferably, at least one element that is flexible in pressure and rigid in tension comprises a cable that is flexible in pressure and rigid in tension or a ribbon that is flexible in pressure and rigid in tension.

[0043] According to one embodiment, the mechanical linking means comprise at least two ribbons that are flexible in compression and rigid in tension.

[0044] According to another embodiment, the mechanical linking means comprise at least two cables that are flexible in pressure and rigid in tension.

[0045] According to yet another embodiment, the mechanical linking means comprise at least one flexible tape under pressure and rigid under tension and at least one flexible cable under pressure and rigid under tension.

[0046] According to another embodiment, mechanical linking means comprise at least three ribbons that are flexible in compression and rigid in tension.

[0047] According to one embodiment, the mechanical linkage means comprise a single ribbon, said ribbon having an actuator termination arranged to be connected to the actuator shaft and a key termination, opposite the actuator termination, arranged to be connected to a key.

[0048] According to one embodiment, the connecting means create a pivot connection between the key and the key termination.

[0049] For example, the key end of the mechanical connecting means has a cylindrical opening, and the connecting means include a pivot shaft such that the cylindrical opening can be fitted onto and pivot about the pivot shaft. Preferably, the connecting means include a removable pivot shaft, also called a connecting shaft, and a body having a bore arranged to receive the removable pivot shaft, said body being arranged to be fixed onto a key and including a slot in a plane transverse to the axis of the bore so as to align the cylindrical opening of the key end of the mechanical connecting means with the bore and to insert the removable shaft into the bore and the opening.

[0050] According to one embodiment, the drilling has, in its cross-section, the shape of an oblong hole so that the connecting shaft can translate laterally. Preferably, the longest length of the oblong hole is at least 20% greater than the width (or shortest length) of the oblong hole.

[0051] According to another embodiment, the mechanical linking means comprise at least two flexible elements in compression and rigid in tension comprising at least two flexible ribbons in compression and rigid in tension, and a joining piece disposed between the two ribbons, said joining piece having two ribbon receiving planes opposite and perpendicular to each other for receiving the terminations of the two ribbons.

[0052] For example, the mechanical linkage means include two ribbons, an actuator ribbon arranged to be connected to the actuator shaft and a key ribbon arranged to be connected to the key, and a joining piece disposed between the two ribbons and provided to receive the terminations of the orthogonally arranged ribbons.

[0053] In one particular embodiment, the mechanical linkage means comprise three flexible elements: two actuator flexible elements arranged to be connected to the actuator shaft and one key flexible element arranged to be connected to the key, and a connecting piece disposed between the key element and the two actuator flexible elements, said connecting piece being arranged to receive the terminations of the three ribbons. Preferably, the two actuator flexible elements are connected to the circumference of the actuator shaft at two diametrically opposite points.

[0054] Preferably, the joining piece has two tape receiving planes that are opposite and perpendicular to each other to receive the two tapes.

[0055] In one embodiment, the joining piece has two slots opposite and perpendicular to each other to receive the two ribbons, so as to be positioned between the two ribbons. Each slot has a thickness greater than or equal to the thickness of one ribbon.

[0056] In another embodiment, the joining piece comprises two joining parts arranged perpendicular to each other, each joining part having a receiving face for attaching a ribbon. For example, the joining piece comprises two plates extending in the same vertical direction. The plates are arranged perpendicular to each other, each plate being drilled to receive a means for attaching a ribbon.

[0057] Advantageously, ribbons with a central thickness increased relative to the thickness near the joining pieces, or shorter ribbons, will be used to both increase the buckling limit and decrease compressibility beyond the buckling limit. Preferably, the central thickness is increased relative to the thickness of the portion of the ribbon that does not wrap around the actuator shaft.

[0058] Depending on embodiment variants, which can be combined with one or more ribbons or a cable, the mechanical linking means include a return piece.

[0059] Preferably, the mechanical linkage means comprise at least two flexible elements, an actuator flexible element arranged to be connected to the actuator shaft and a key flexible element arranged to be connected to the key, and a return piece having a pivot axis, said return piece being disposed between two flexible elements, said return piece being arranged to achieve a non-rectilinear path of the mechanical linkage means.

[0060] According to a particular embodiment, the mechanical linkage means comprise three ribbons, an actuator ribbon arranged to be connected to the actuator shaft, a first key ribbon, a connecting piece disposed between the actuator ribbon and the first key ribbon, a second key ribbon arranged to be connected to the key, and a return piece disposed between the first key ribbon and the second key ribbon and provided to receive the terminations of the ribbons extending orthogonally.

[0061] For example, the return piece is a pulley or an "L"-shaped lever-operated actuation piece.

[0062] According to a first embodiment, the return element is a fixed or rotating pulley, such that a ribbon or cable is in contact with said pulley. In operation according to a particular pulley arrangement, the pulley makes a quarter turn, or the ribbon or cable travels a quarter of the circumference of the fixed pulley. Preferably, the mechanical linkage means further include a counter-pulley or guide with an axis parallel to the axis of the pulley. The counter-pulley or guide is arranged near the pulley so that the ribbon or cable is in contact simultaneously with the pulley on one side and with the counter-pulley or guide on the other.

[0063] According to a second embodiment, the mechanical linkage means include a lever-shaped actuating element. For example, the lever-shaped actuating element is L-shaped or right-angled. The lever-shaped actuating element includes a pivot point at the intersection of the two arms of the L or the two arms of the right-angled element. In one embodiment, the L-shaped actuating element is located under the key and is connected near the key return.

[0064] Optionally, the lever actuating piece may incorporate a connecting piece. One or both ends of said piece may include a slot as defined above for the connecting piece.

[0065] The following, though not exhaustive, are presented as different embodiments comprising a combination of the characteristics proposed above: the rotary electric actuator has an axis of rotation parallel to the axis of the key, the mechanical linkage means comprising a cable or ribbon connecting the actuator to the key; the rotary electric actuator has an axis of rotation parallel to the axis of the key, the mechanical linkage means comprising a cable or ribbon connecting the actuator to the key, and a return piece between the actuator and the key in order to modify the trajectory of said cable or ribbon, the return piece having an axis of pivot parallel to the axis of the key; the rotary electric actuator has an axis of rotation parallel to the axis of the key, the mechanical linkage means comprising two flexible elements, which may be two cables or two ribbons or one cable and one ribbon, connecting the actuator to the key, and a return piece having an axis of pivot parallel to the axis of the key, the two flexible elements being separated by the return piece;the rotary electric actuator has an axis of rotation parallel to the longitudinal direction of the key, the mechanical linkage means comprising a cable connecting the actuator to the key; the rotary electric actuator has an axis of rotation parallel to the longitudinal direction of the key, the mechanical linkage means comprising a ribbon connecting the actuator to the key, and connection means comprising a cross-sectional drilling in the shape of an oblong hole so as to provide operating clearance in a direction parallel to the longitudinal direction of the key; the rotary electric actuator has an axis of rotation parallel to the longitudinal direction of the key, the mechanical linkage means comprising two ribbons connecting the actuator to the key, and a connecting piece being disposed between the two ribbons;the rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the axis of rotation of the key, the mechanical linkage means comprising two flexible elements, the two flexible elements being able to be one or two cables or two ribbons or one ribbon and one cable, connecting the actuator to the key, and a return piece having an axis of pivot parallel to the axis of the key, the two flexible elements being separated by the return piece, the return piece being able to be further a joining piece in the presence of one or two ribbons;the rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the axis of rotation of the key, the mechanical linkage means comprising two flexible elements, the two flexible elements being able to be two ribbons or a ribbon and a cable, connecting the actuator to the key, and an L-shaped lever actuating piece having an axis of pivot parallel to the axis of the key, the two flexible elements being separated by the lever actuating piece, the lever actuating piece comprising, at the end intended to connect the actuator ribbon, a cross-section bore in the shape of an oblong hole so as to achieve an operating clearance in a direction parallel to the longitudinal direction of the key;the rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the axis of rotation of the key, the mechanical linkage means comprising two ribbons connecting the actuator to the key, a connecting piece being disposed between the two ribbons, and a return piece in particular a pulley, in addition to the connecting piece, having an axis of pivot parallel to the axis of the key, the return piece being disposed so as to be in contact with the key ribbon in order to modify its trajectory;The rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the axis of rotation of the key, the mechanical linkage means comprising three ribbons, or two ribbons and a cable, connecting the actuator to the key, a connecting piece being disposed between the first two ribbons, and a return piece, in particular a lever-operated actuation piece, in addition to the connecting piece, having a pivot axis parallel to the axis of the key, the lever-operated actuation piece being disposed between the second ribbon and the third ribbon or cable.

[0066] According to another particular embodiment, the mechanical linkage means comprise at least two ribbons, an actuator ribbon arranged to be connected to the actuator shaft and a key ribbon arranged to be connected to the key, a joining piece disposed between the two ribbons, and provided to receive the terminations of the ribbons arranged orthogonally to each other, and a pulley on which the key ribbon cooperates.

[0067] In other embodiments, the rotary electric actuator has an axis of rotation perpendicular to the longitudinal direction of the key and to the key's axis of rotation, and offset from a plane passing through the key's thickness. In these cases, the return elements have a pivot axis parallel to the longitudinal direction of the key. According to this configuration, the various embodiments comprising a combination of features are presented below: the mechanical linkage means comprising two flexible elements, the two flexible elements being able to be two cables or two ribbons or one ribbon and one cable, connecting the actuator to the key, and a return piece separating the two flexible elements, the return piece being able to be a pulley or an L-shaped lever actuating piece, in the case of an actuator ribbon and an L-shaped lever actuating piece, the latter being able to include at the end intended to connect the actuator ribbon, a cross-section bore in the form of an oblong hole so as to provide operating clearance in a direction parallel to the pivot axis of the key, and / or in the case of a key ribbon, the mechanical linkage means comprising connecting means including a cross-section bore in the form of an oblong hole so as to provide operating clearance in a direction parallel to the longitudinal direction of the key;the mechanical linkage means comprising two ribbons connecting the actuator to the key, a connecting piece separating the ribbons and a pulley having a pivot axis parallel to the longitudinal direction of the key and being arranged so as to be in contact with the key ribbon in order to modify its trajectory;the mechanical linkage means comprising three flexible elements, which may be three ribbons or two ribbons and a cable, connecting the actuator to the key, a connecting piece separating the first and second ribbons and / or a connecting piece separating the second and third ribbons, a pulley having a pivot axis parallel to the longitudinal direction of the key and being arranged so as to be in contact with a ribbon in order to modify its trajectory, and an L-shaped lever actuating piece separating the two flexible elements, the mechanical linkage means comprising connecting means including a cross-section drilled in the shape of an oblong hole so as to provide operating clearance in a direction parallel to the longitudinal direction of the key;the mechanical linkage means comprising four ribbons connecting the actuator to the key, a connecting piece separating the first and second ribbons and / or a connecting piece separating the third and fourth ribbons, and an "L"-shaped lever actuation piece separating the second and third ribbons.

[0068] According to one embodiment, the mechanical linkage means comprise at least two ribbons, at least one actuator ribbon arranged to be connected to the actuator shaft and at least one key ribbon arranged to be connected to the key, and a lever-operated actuation piece disposed between the two ribbons and provided to receive the terminations of the orthogonally arranged ribbons.

[0069] For example, each ribbon has the following dimensions: actuator ribbon: length between 25 and 50 millimeters, preferably between 15 and 40 millimeters, preferably greater than 15 millimeters, width between 5 and 10 millimeters, and thickness of 0.05 millimeter; key ribbon: length between 15 and 30 millimeters, preferably between 5 and 30 millimeters, preferably greater than 5 millimeters, preferably greater than 10 millimeters, width between 5 and 10 millimeters, and thickness of 0.05 millimeter.

[0070] Preferably, the mechanical fastening means are metallic. The actuator and key ribbons may be metallic actuator and key ribbons.

[0071] The material of the ribbons comprises or is made of metal (steel, preferably stainless steel, or aluminum), or a fibrous polymer or composite material, and / or synthetic fiber textile, for example Kevlar (registered trademark).

[0072] The ribbons provide the necessary traction to activate the key while allowing slight flex, ensuring compatibility between the key's rotation and the ribbon's translational movement when pulled by the actuator. A second function, achieved through the ribbons' limited flexibility, is to restrict the actuator's travel when the key is decelerated, as it is driven by its own inertia. This helps prevent or dissipate rebound vibrations. Furthermore, the flexible ribbon connection avoids the drawback of mechanical play and offers the advantage of a stable equilibrium configuration when the traction force is released.

[0073] In another embodiment, the haptic device includes an actuator stop disposed on the periphery of the actuator's rotating shaft or around it, so as to control the angular deflection of the actuator's rotating shaft, particularly if the connecting means employ cables. For example, the stop may be disposed on the actuator's rotating shaft or near it, for example, tangentially. In one embodiment, the stop is cylindrical in shape. The actuator stop is located in the immediate vicinity of the connecting means or the actuator. Preferably, the actuator stop is reached at the moment the touch reaches the stop position.

[0074] The presence of at least one flexible element in compression and rigid in tension, and / or the presence of the actuator stop, constitutes a mechanical means of controlling the movement of the mechanical linkage. These control means allow the angular displacement of the actuator's rotation shaft to be controlled as a function of the angular displacement of the key. They also prevent unwanted or excessive movement of the linkage.

[0075] Advantageously, the mechanical means for controlling the movement of the mechanical linking means are mechanical in nature and are located in the immediate vicinity of the linking means and the actuator, said means having the function of maintaining the linking means and the actuator in the geometric configuration which they have in absolute terms and in relation to the key at the moment when the traction ceases.

[0076] Preferably, the mechanical means for controlling the displacement of the mechanical linkage means should include at least one flexible element. The use of ribbons largely ensures this geometric restoration function thanks to their naturally stable equilibrium configuration.

[0077] A wire connection, in particular not having a natural configuration of stable equilibrium, presents the disadvantages of a difficulty in fixing and a complication of limiting the motor stroke which must be ensured by other means: actuator stop or electrical means of position control.

[0078] Additionally, the actuator can be controlled according to a four-quadrant operation, to participate in the control of the mechanical linkage means and prevent the motor from running on its momentum.

[0079] Preferably, the haptic device also includes means for holding the key in the up position. Holding in the up position means holding it in its home position. These means also allow the key to return to its home position when the user is not pressing it. In particular, the means for holding the key in the up position may be independent of the rotary electric actuator. For example, the means for holding the key in the up position may include at least one spring, at least two permanent magnets, or a holding actuator that carries a current continuously when the key, thus equipped, is not in use.

[0080] In another embodiment, the computing means can control the rotary electric actuator to perform the holding function in the raised position via mechanical linkage means. Preferably, the computing means include four-quadrant control means for actuating the electric actuator.

[0081] The detection means are arranged and configured to detect or measure the position and / or acceleration of the associated key or the force applied by the user to said associated key. They provide information for the calculation algorithm implemented by the calculation means.

[0082] Preferably, the key detection means include key kinematic sensors. Examples of such sensors include position sensors, motion sensors, acceleration sensors, and angular velocity sensors.

[0083] Means of detecting the touch include force sensors, for example of the strain gauge type.

[0084] According to one embodiment, the means for detecting the touch include two sensors.

[0085] According to one embodiment, the detection means are placed under the key, preferably on the underside of the key.

[0086] According to another embodiment, the detection means include a means for measuring the current of the actuator.

[0087] The computing means preferably include an integrated microprocessor on a standalone card, a control interface and software including a mathematical model of the dynamics of the mechanism of the real instrument that one seeks to reproduce.

[0088] Preferably, the computing means include an actuator module incorporating a mechanical control model for at least one key of at least one acoustic musical instrument. This module incorporates a mathematical model of the dynamics of the mechanism of the actual instrument to be reproduced. The module also incorporates a mathematical model of the dynamics of the digital keyboard mechanism used to reproduce the actual instrument in the absence of electrical control. Preferably, the computing means include an actuator module incorporating a mechanical control model for at least one key of the keyboard described herein when the associated actuator receives no electrical current. This module incorporates a mathematical model of the dynamics of the keyboard mechanism used to reproduce the actual instrument, rendered passive by the absence of electrical control.The module also incorporates a mathematical model of the dynamics of the key, the means of connection and the actuator, in the absence of electrical control.

[0089] Regarding the mathematical model of the dynamics of the mechanism of the real instrument that we seek to reproduce, we will refer for example to the publication "Non-smooth model of the grand piano action" by Anders Thorin (https: / / pastel.archives-ouvertes.fr / pastel-00939493).

[0090] According to a second aspect, the invention proposes an electronic musical instrument keyboard with haptic feedback comprising at least one key and at least one haptic device, each key being associated with a device according to one or more of the characteristics of the first aspect.

[0091] According to a third aspect, the invention proposes an electronic musical instrument, for example an electronic piano, comprising at least one haptic device according to one or more of the characteristics of the first aspect or comprising a keyboard according to the second aspect.

[0092] Preferably, the electronic musical instrument includes several haptic devices. The haptic devices are arranged side by side. In one embodiment, the haptic devices are arranged so that the rotating electrical actuators are arranged parallel to each other.

[0093] According to a fourth aspect, the invention proposes a method for controlling an electronic musical instrument comprising at least one haptic device according to one or more of the characteristics of the first aspect.

[0094] The method aims to control, based on a given movement of a user on a key as measured by the pressure detection means, at least one rotary electric actuator associated with said key so as to exert a predetermined resisting force against the user's pressing force. This resisting force corresponds substantially to the force that the key of a similar traditional or acoustic instrument would exert to produce the same movement, and thus emulates the dynamics of mechanisms found in traditional instruments.

[0095] The control method includes at least the following steps: - a step of detecting the pressing of a user on the key by the detection means, - a step of real-time control of the actuator to exert a pulling force on the key so as to resist the pressing force, or to exert a pulling force so as to return the key to its original position.

[0096] The detection means periodically measure the position and / or acceleration of the key and then transmit this information to the computing means. The computing means calculate the forces generated in a real instrument mechanism based on a mathematical model of the dynamics of said mechanism.

[0097] The computing resources must have sufficient processing power to simulate the key model in real time. The cycle time (Measurement / Calculation / Actuation) is constrained and defined by the movement of the piano key. The sampling frequency is, for example, 2 kHz. At lower values, the simulation of a traditional piano key exhibits instabilities. The computing resources are, for example, a computer.

[0098] Preferably, in order to transmit information between the different components, the computing resources also include: power electronics, signal electronics, real-time simulation model-based computing boards, a MIDI hub (short for Musical Instrument Digital Interface), a router.

[0099] The computing resources are used to process the measured signals, perform real-time calculations of the dynamics of the traditional keyboard and the numeric keypad (simulation), and develop the command to be applied to the actuator.

[0100] The computing means calculate the current or voltage to be applied to the actuator, based on a dynamic model of the musical instrument to be simulated and real-time measurements from the detection means.

[0101] The control method according to the invention thus makes it possible to emulate or simulate the dynamics of mechanisms: adjustable and modifiable at little cost; different, on the same keyboard but referring to different instruments, for example harpsichord, pianoforte, clavichord or organs; which do not exist in acoustic instruments but which one might wish for, for example concerning modern pianos with light keys, this would allow for example better control by very young apprentice pianists; which do not exist because of physical problems, such as keys without dry friction, hammer escape point extremely close to the point of impact on the string, and which are desirable for various reasons, for example greater ease of control of playing in piano dynamics, greater possible repetition speed, but whose possible adoption poses some epistemological problems.

[0102] The computing cards perform real-time calculations to emulate the dynamics of the keys of a traditional keyboard, via the processing of signals from sensors, and the measurement of power electronic circuits associated with actuators and possibly via the application of force signal control algorithms, aimed at correcting certain imperfections of the system for example delays.

[0103] According to a preferred configuration in which an actuator is associated with a single key, the control method provides for closed-loop control of at least one rotary electric actuator such that said at least one actuator exerts a time-varying force, according to the command given by the computer in real time and relayed by power electronics.

[0104] Each processing board provides the MIDI codes corresponding to the notes played on the keys it controls, using an electronic circuit. These codes are converted into signals conforming to the MIDI standard. The signals from the various processing boards are transmitted to a MIDI hub (internal or external), which then sends the necessary MIDI codes for sound synthesis to the computer (in the case of standalone prototypes) or to the digital piano. For standalone prototypes, the computer performs sound synthesis using sound synthesis software, such as Pianoteq (registered trademark). BRÈVE DESCRIPTION DES FIGURES

[0105] Other features and advantages of the invention will become apparent from the detailed description of the invention which follows with reference to the attached figures, in which: There figure 1 is a schematic profile view of a haptic control device according to a first embodiment associated with a key of an electronic upright piano, the device comprising an electric motor and mechanical linkage means of the type of metal strips between the motor and an upper face of the key, the axis of rotation of the motor being parallel to the longitudinal direction of the key; The figure 2a is a schematic profile view conforming to the figure 1 representing in an exaggerated way the movement of the key and the mechanical linking means, the figure 2a illustrating the original position; The figure 2b is a schematic profile view conforming to the figure 1 representing in an exaggerated way the movement of the key and the mechanical linking means, the figure 2b illustrating a stop position when a user presses down; The figure 3a is a perspective view of three haptic control devices according to the first embodiment, each device comprising mechanical linking means according to one embodiment; The figure 3b is a detailed view of the figure 3a in the area containing the actuator shafts, each device includes an actuator stop positioned near the respective shaft; The figure 4a is a schematic profile view of a haptic control device according to a second embodiment, in which the motor is located below the lower face of the key and the mechanical linkage means are located above the upper face of the key return of a flat piano, the axis of rotation of the actuator being parallel to the longitudinal direction of the key; The figure 4b is a cross-sectional view of an example of the implementation of a haptic device conforming to the figure 4a ; There figure 4c is a perspective view of an example of the implementation of a haptic device which is a variant of the implementation method represented by the figure 4a ; There figure 4d is a perspective view of a variant embodiment of the previous figure; The figure 5a is a schematic perspective view of a haptic control device according to a third embodiment, in which the motor and mechanical linkage means are located above the upper face of a key, the axis of rotation of the actuator being perpendicular to the longitudinal direction and the pivot axis of the key, the mechanical linkage means further comprising a pulley cooperating with the key strip; The figure 5b is a view consistent with the figure 5a , and further comprising a counter-pulley whose peripheral surface is in contact with the touch strip, said counter-pulley being arranged substantially tangentially to the pulley; The figure 5c is a schematic perspective view of a haptic control device according to a fourth embodiment, in which the motor and mechanical linkage means are located above the upper face of a key, the axis of rotation of the actuator being perpendicular to the longitudinal direction and the pivot axis of the key, the mechanical linkage means further comprising a rotating bracket and an additional ribbon located between the actuator ribbon and the bracket; The figure 6a is a schematic profile view of a haptic control device according to a fifth embodiment, in which the motor is located below the underside of the key and the mechanical linkage means are connected to the upper side of the key return of a flat piano, the axis of rotation of the actuator being perpendicular to the longitudinal direction and to the pivot axis of the key, the mechanical linkage means further comprising a pulley, the key ribbon guide being able to be placed in the immediate vicinity of the pulley is not shown; The figure 6b is a schematic profile view of a haptic control device according to a sixth embodiment, in which the motor is located below the underside of the key and the mechanical linkage means are connected to the upper side of the key return of a flat piano, the axis of rotation of the actuator being perpendicular to the longitudinal direction and the pivot axis of the key, the mechanical linkage means further comprising a rotating bracket and an additional ribbon located between the bracket and the actuator ribbon, the latter being guided by a series of double guides with vertical axes; The figure 6c is a cross-sectional view of an example of the implementation of a haptic device conforming to the figure 6b , also including actuator ribbon guides; The figure 6d is a partial perspective view of a haptic control device according to an alternative embodiment comprising an actuator stop disposed near the actuator's rotation shaft, the figure 6d showing the state in which the actuator ribbon assembly means are in contact with said stop; The figure 6e is a profile view of an example of a haptic device implementation which is a variant of the embodiments represented by the figures 6a, 6b And 6c , including a winch wheel; The figure 7 is a perspective view of assembly methods according to a given embodiment; The figure 8a is a perspective view of an example of the implementation of the joining piece between two ribbons; The figure 8b is a perspective view of another example of the implementation of the joining piece between two ribbons; The figure 9a is a perspective view of an example of a connecting piece being made; The figure 9b is a perspective view of another example of the fabrication of a connecting piece; The figure 10 represents an electrical diagram of a haptic control device; The figure 11 represents a diagram for calculating the restraint forces based on the dynamics of traditional or acoustic instruments; The figure 12 is a schematic perspective view of a haptic control device according to a seventh embodiment associated with a key of an electronic upright piano, the device comprising an electric motor and mechanical linkage means comprising a single metal strip between the motor and an upper face of the key, the axis of rotation of the motor being parallel to the axis of pivot of the key; The figure 13 is a schematic perspective view of four haptic control devices, two haptic control devices conforming to the preceding embodiment and two haptic control devices according to an eighth embodiment, in which each device comprises a motor located below the underside of the associated key and mechanical linkage means connecting a key feedback of the associated key, the mechanical linkage means comprising a single metal strip between the motor and a face of the key feedback, the axis of rotation of the motor being parallel to the pivot axis of the key, one of the two devices further comprising a return pulley; The figure 14 is a schematic perspective view of a haptic control device according to a ninth embodiment associated with a key of an electronic upright piano, the device comprising an electric motor and mechanical linkage means including a single metal strip between the motor and an upper face of the key, the axis of rotation of the motor being parallel to the longitudinal direction of the key, the mechanical linkage means including connecting means arranged to provide operating clearance along the longitudinal direction; The figure 15 is a perspective view of the means of connection in accordance with the figure 14 featuring a hole drilled along an axis perpendicular to the longitudinal direction of the key; The figure 16 is a perspective view of three haptic control devices according to a tenth embodiment, each device comprising mechanical linkage means according to a particular embodiment comprising two flexible actuator elements per device; The figure 17 is a perspective view of a haptic control device according to an eleventh embodiment, which is a variant of the previous embodiment.

[0106] For clarity, identical or similar elements of the different embodiments are identified by identical reference symbols across all figures. DESCRIPTION DÉTAILLÉE DE L'INVENTION

[0107] THE figures 1, 2a et 2b represent a first embodiment of a haptic control device 1 for an electronic musical instrument. The instrument, for example a piano as illustrated in figures 3a And 16, is a musical instrument consisting of a keyboard with several keys, only one of which is represented in the figures 1, 2a et 2b .

[0108] The haptic device and the K key are shown in profile, with the key represented by a horizontal rectangle. The K key illustrates a piano key. It is mounted to pivot around the pivot axis A1 relative to a frame, for example, the chassis of a keyboard, see figure 3a And 16 The pivot axis A1 is represented by two dashed lines perpendicular to each other, representing a target, on a disk representing a rotation shaft. The pivot axis A1 is shown under the K key near one of its proximal ends, to the left of the figures 1, 2a et 2b Near a second end, called the distal end, opposite the first end, and above the upper face K1 of said key, there is a representation of a finger of a user of the musical instrument, visible only on the figure 1 .

[0109] Beneath the key, near the distal end, the haptic device includes means for detecting and / or measuring 30° of key presses and movements by the user. With reference to the figure 1 The detection and / or measurement means include two motion sensors 31, 32, for example accelerometers. They are arranged to measure the movements of the key and to transmit this information to the computing means, also called servo and control means, of the haptic device, not shown.

[0110] The haptic control device 1 comprises a rotary electric actuator 10. Preferably, said actuator is a DC electric motor whose motor shaft extends along axis B1. The motor is arranged relative to the key K such that the axis of rotation B1 is parallel to the longitudinal direction K0 of the key K, particularly in the home position, and that said direction K0 and the axis B1 are vertically aligned. In this embodiment, the axis of rotation B1 is substantially horizontal.

[0111] With reference to figures 1, 2 , 3a And 16 The haptic control device further includes mechanical linkage means 20 connecting the motor shaft 10 to the upper face K1 of the key. The mechanical linkage means 20 comprise several elements or parts connected one after the other: assembly means 25 (not visible on the figures 1 et 2 ), an actuator strip 24 (two actuator strips 24a, 24b on the figure 16 ), a connecting piece 23, a touch strip 22 and connecting means 21.

[0112] The assembly means allow the actuator strip to be connected to the rotating shaft of the electric motor, see figures 3a et 3b For example, with reference to the figure 7 The assembly means 25 comprise a winding piece 25e and a clamping piece 25s, or bracket with two arms. The winding piece has a bore arranged to be fitted onto the rotating shaft of the electric motor, see figures 3a et 3b It also features a rectangular portion extending radially from the bore, in which a slot is formed to allow for insertion. The clamping piece 25s has a U-shape to overlap the rectangular portion of the winding piece 25e. The clamping piece includes, in one of its arms, a thread arranged to be perpendicular to the rectangular portion of the winding piece. When the actuator strip is fixed, it is held between an inner face of the clamping piece and a first outer face of the rectangular portion, see figures 3a et 3b The face opposite the first face receives the end of a screw which is mounted in the threaded hole of the clamping piece. The screwing action allows both the slot in the rectangular portion of the winding piece to be closed to clamp it onto the motor shaft and to press the end of the actuator strip into place until it is fully tightened.

[0113] The actuator strip 24 is located between the assembly means 25 and the connecting piece 23. The actuator strip extends vertically and tangentially to the motor's rotation shaft.

[0114] The key strip 22 is located between the connecting piece 23 and the connecting means 21. The key strip extends vertically and along a plane parallel to the plane transverse to the key, in particular in the home position.

[0115] According to another embodiment and with reference to the figure 16 , which will be described by its differences from the figure 3a The mechanical linkage means 20 comprise a pair of actuator ribbons 24a and 24b. Each ribbon 24a, 24b connects the actuator 10 to the connecting piece. The two ribbons are fixed, via sleeve-shaped assembly means 25, to the circumference of the actuator shaft 10. The actuator ends of the ribbons 24a, 24b are arranged diametrically opposite each other. The actuator ribbon 24a is directly connected between the connecting piece and the actuator. The actuator ribbon 24b is connected between the connecting piece and the actuator via a wheel 11. The wheel 11 is positioned in a raised manner relative to the actuator so that the ribbon 24b winds around the wheel 11 before being fixed at a point on the circumference of the actuator which is substantially diametrically opposite to the hooking point of the actuator termination of the ribbon 24a.This arrangement allows, when the actuator is actuation, for a double, opposite-direction pull to be exerted around the actuator shaft. The actuator strips 24a and 24b are arranged substantially symmetrically with respect to a plane that is both parallel to the axis of the actuator and to the longitudinal direction of the key associated with the device comprising said strips.

[0116] According to one alternative embodiment represented by the figure 17 The actuator comprises two half-shafts 111, 112, and the mechanical linkage means 20 comprise a single actuator strip 24 that passes between the two half-shafts of the drive shaft before being connected to the wheel 11. Each half-shaft has, along its longitudinal axis, a rectangular face, one side of which corresponds to the diameter of a shaft and a curved face corresponding to a circular half-cylinder. The joining of the half-shafts forms a shaft.

[0117] The ribbon (or cable) passes through the actuator shaft (motor) between two half-shafts clamped together on the motor shaft by means of the clamping piece comprising two half-cylinders clamped together, for example by two screws.

[0118] The two ends of the ribbon (or cable) meet at the key. In this way, both ends of the ribbon (or cable) exert the same force on the key (and these forces are additive), but they also exert forces of opposite signs on the motor shaft. Consequently, a force is exerted on the key and a zero net force is exerted on the motor.

[0119] To ensure that the force exerted on the key allows it to pull straight along the vertical axis without deviating laterally, an intermediate direction-changing device, for example a pulley or a wheel 11, is used.

[0120] With reference to the figure 8a The junction piece 23 comprises two slots 26, 27, opposite and perpendicular to each other, for receiving the terminations of the two ribbons 22, 24. The junction piece performs the function of a ribbon orientation converter. One end of the junction piece has the slot 26 arranged to receive the termination of the actuator ribbon 24, and a second end, opposite the first end, has the slot 27 arranged to receive the termination of the key ribbon 22.

[0121] According to another embodiment of the connecting piece shown in the figure 8b The joining piece 23 comprises two plates extending in the same vertical direction. The plates are arranged perpendicular to each other, each plate being drilled to receive a means for fixing a tape.

[0122] Finally, the connection means 21 are fixed to the upper face K1 (on the figures 1, 2a et 2b ) of the K key. In reference to the figure 9a The connecting means consist of two rods: a connecting rod 21a and a key rod 21b. The connecting rod 21a has, at one end, called the slotted end, a slot arranged to receive a key ribbon termination. This slot is oriented in a plane parallel to the transverse plane of the key. The key rod has a threaded body arranged to fit into a threaded hole in the key. The key rod has a hollow body to receive one end of the connecting rod, opposite the slotted end. The peripheral wall of the hollow body has a radially extending threaded hole to receive a screw for locking the position of the connecting rod in the key rod.

[0123] According to another embodiment represented in the figure 9b The connection means 21 comprise two plates arranged perpendicular to each other and in different directions. The first plate extends horizontally to be attached to the K key, and the second plate extends vertically to be connected to the key strip. Each plate includes a hole for the passage of a screw.

[0124] With reference to the figure 1 The connection means are positioned on the key, at a contact point located at a distance equal to 25% of the longitudinal distance of the key from the pivot axis A1. Preferably, the contact point is located between the middle of the key and the distal end of the key. Ideally, they are fixed as far as possible from the pivot axis A1.

[0125] For example, the connecting means are arranged on the key so that the contact point is located at a distance of at least 50 millimeters, preferably at least 100 millimeters, advantageously at least 150 millimeters from the pivot axis. The assembly means, in particular the winding piece, are arranged on the motor shaft so that the actuator point is located at a distance of 3 millimeters from the motor shaft. In the case of these latter specifications (150 and 3 millimeters), the reduction ratio of angular displacement between the motor and the key, or torque multiplication ratio, is equal to 50.

[0126] Preferably, each slot, or each hole in the connecting parts, is associated with a fastening means, for example a screw. For example, a thread is made extending radially or perpendicularly to the axis of the part in order to receive a screw.

[0127] With reference to the figure 2a The K key is in a substantially horizontal or raised position. When the upper face K1 is pressed near the distal end of the key, the key is pivoted so that the distal end lowers and the key strip 22 tilts and flexes due to the key's pivoting; see figure 2b The actuator strip 24 unwinds while remaining vertical, held in place by the electric motor 10, which is powered to reproduce the dynamics of a keyboard mechanism of an acoustic instrument (or any other predetermined dynamics). Each motor is current-controlled. When a key is pressed, the motor's torque brakes its descent (generator operation). When the key is released, the same current control raises the key (motor operation). The torque generated by the motor always has the same sign; only the direction of rotation changes between pressing and releasing the key (two-quadrant operation). figure 10 represents the power electronics diagram of the device. According to another embodiment, the computing means can control the actuator in such a way as to achieve, by means of ad hoc modifications to the power electronics diagram, a four-quadrant operation.

[0128] With reference to figures 3a et 3b The diagram shows the arrangement of electric motors in the case of a keyboard with multiple keys, specifically the black and white keys of a piano. The electric motors are arranged so that the rotating shafts are in two horizontal rows, offset so that the mechanical linkages are aligned.

[0129] THE figures 4a et 4b represent a second embodiment which will be described by its differences from the previous one.

[0130] The key shown corresponds to a key on a flat piano, said key including a key return R extending under the key from its distal end to form an "L". In this case, the rotary electric actuator and the mechanical linkage means are located above the upper face K2 of the key return. The distance between the upper face K2 of the key return and the lower face K3 is, for example, 45 millimeters. With reference to the figure 4a The connection means are fixed to the upper face K2 of the key return. With reference to the figure 4b , the end of the key ribbon is fixed to the distal transverse face of the R key return.

[0131] According to one alternative embodiment represented by the figure 4b The lower face K3 of the key may have a recess, for example concave in shape, to partially house the actuator. This feature allows for an even more compact device.

[0132] According to another embodiment represented by the figure 4c , and which will be described by its differences from the figure 4a The device includes a threaded rod disposed at the end of the actuator's drive shaft. Preferably, the threaded rod is a V-screw.

[0133] Furthermore, the device includes a latching finger P disposed on the key return. The finger is located above the threaded rod, preferably substantially parallel to the motor shaft or the threaded rod. According to the embodiment shown, the latching finger has a cylindrical shape and is fixed on a face perpendicular to the upper face K1.

[0134] In addition, the mechanical linkage means 20 include two cables, a cable 24c1 connecting the distal end of the touch return to the threaded rod, and a cable 24c2 connecting the threaded rod to the hook finger.

[0135] In operation, the key return R and the latching finger P are fixed together in translation, for example vertically as shown in the embodiment, when the key moves up or down. The screw V is fixed to the actuator shaft and rotates about the geometric axis of the motor shaft. The threaded rod, in particular the screw V, does not translate.

[0136] Preferably, the mechanical linkage means 20 comprise a single cable 24c having two strands, 24c1 and 24c2. In this case, the cable 24c is wound in one or more turns around the screw V and is fixed to said screw to prevent the cable from slipping. For example, the cable 24c is fixed to the screw or threaded rod by gluing. Preferably, the strands or portions of cables 24c1 and 24c2 emerge from the same side of the threaded rod or screw V. The role of the cable strand 24c2 (whose end is fixed to the key) is to block the rotation of the actuator by stopping its momentum when the key reaches its lower stop. The cable strand 24c2 exerts force only when the key stops, serving only to restrain the motor. During operation and when the key is pressed, the strand of cable 24c2 winds around the screw V and the strand of cable 24c1 unwinds from the screw V.

[0137] According to yet another variant of the embodiment represented by the figure 4d , and which will be described by its differences from the previous variant. The device further includes a pulley or wheel 121 and a cable 24d comprising two strands 24d1 and 24d2. According to the figure 4d The pulley 121 is positioned above the screw V and is fixed to the actuator frame, the axis of said pulley 121 being substantially parallel to the axis of the actuator. The cable 24d runs approximately halfway around the circumference of the pulley 121 and is partially wound around the threaded rod or screw V. The cable strand 24d1 connects the distal end of the feedback loop to the pulley 121, tangent to, but not touching, the threaded rod or screw V, and the cable strand 24d2 connects the pulley 121 to the threaded rod or screw V. The connection point of the distal end of strand 24d2 is fixed to the periphery of the threaded rod at a point diametrically opposite the connection point of the distal end of cable strand 24c2. With reference to the figure 4d The connection points are also axially offset. As in the previous variant, the strands 24c1 and 24c2 are fixed to the threaded rod or the V-screw on the same side or axially offset along a peripheral line of said V-screw.

[0138] During operation, when a key is pressed, cable strand 24c2 winds around screw V, decreasing in length. Cable strand 24d2 unwinds from screw V, cable strand 24c1 unwinds from screw V, increasing in length, and cable strand 24d1 also increases in length. Both cables 24c and 24d exert opposing forces on the actuator shaft, while simultaneously providing a cumulative force on the key return. Cable 24d pulls on the key, just like strand 24c1, but, thanks to the return pulley 121, it also pulls on the motor in the opposite direction to that of strand 24c1, while simultaneously rotating the actuator in the same direction.

[0139] The figure 5a This represents a third embodiment, which will be described by its differences from the first embodiment. The electric motor 10 is located above the K key and is fixed to the frame (not visible in the figure). The rotation axis B1 of the electric motor is perpendicular to the longitudinal direction of the K key. The actuator strip 24 extends horizontally and tangentially to the motor's rotation shaft. For simplicity, the assembly, joining, and connection means are not shown here. The mechanical connection means further include a pulley 28 whose rotation axis is parallel to the pivot axis A1. The pulley is connected to the frame, which is not visible in the figure. The pulley allows the key strip 22 to be received on its circumference along its path. Between the joining piece and the pulley, the portion of the key strip extends substantially horizontally.Between the pulley and the connecting means, the portion of the touch strip extends substantially vertically. According to an alternative embodiment represented by the . figure 5b The device further includes a counter-pulley 51 having the shape of a cylinder and is arranged tangentially to the pulley 28. The counter-pulley is in contact or near-contact with the touch strip 22. The counter-pulley allows to guide and / or control the movement of the touch strip and thus keep the touch strip on the periphery of the pulley 28. The counter-pulley prevents the touch strip from lifting off the pulley.

[0140] There figure 5c This represents a fourth embodiment, which will be described by its differences from the previous embodiment. The mechanical connection means include, in place of the pulley 28, a bracket 29 whose axis of rotation C1 is parallel to the pivot axis A1. The axis C1 of the bracket is connected to the frame, which is not visible in the figure. The bracket receives the touch strip 22 along its path. The touch strip 22 comprises a first touch strip 22b and a second touch strip 22a. Between the connecting piece and the bracket, the first touch strip 22b extends substantially horizontally. Between the bracket and the connection means, the second touch strip 22a extends substantially vertically.

[0141] There figure 6a This represents a fifth embodiment, which will be described by its differences from the third embodiment. The key shown corresponds to a key on a flat piano, said key including a key return R, as in the second embodiment. The electric motor 10 is located below the key K. The motor's axis of rotation B1 is perpendicular to the longitudinal direction of the key and perpendicular to the pivot axis A1. The mechanical connecting means extend under the lower face K3 of the key. The pulley 28 is located between the upper face of the key return R and the lower face K3 of the key. The connecting means, which are not visible, are fixed to the upper face K2 of the key return.

[0142] There figure 6b represents a sixth embodiment which will be described by its differences from the previous embodiment. The pulley 28 is replaced by the bracket 29, whose arrangement relative to the touch and actuator strips is similar or identical to the fourth embodiment.

[0143] According to one alternative embodiment represented by the figure 6c In this embodiment, which will be described by its differences from the previous one, the actuator 10 is positioned near the pivot axis A1. The device further includes one of the ribbon guides 61 for guiding the movement of the actuator ribbon 24. Each ribbon guide comprises a pair of rods spaced apart so that the ribbon can translate between them; see also the figure 6d .

[0144] With reference to the figure 6d Representing an alternative embodiment that can be integrated into all previous embodiments, the mechanical connection means further include an actuator stop 42 positioned near the actuator's rotation shaft so as to restrict the angular deflection of said shaft. The stop 42 has a cylindrical shape and is fixed to a frame. The stop 42 is designed to limit the rotation of the actuator's rotation shaft via the assembly means 25.

[0145] According to one alternative embodiment represented by the figure 6e The device comprises a wheel 291 and a roller 292 arranged coaxially, the diameter of the wheel 291 being greater than the diameter of the roller, for example, at least three times greater. The wheel 291 and roller 292 assembly is positioned near the key return so that the key ribbon 22 is connected to the roller 292 and to the distal end of the key return. Compared to previous embodiments, the actuator ribbon 24 is replaced by a cable 24e having two strands, 24e1, referred to as the lower strand, and 24e2, referred to as the upper strand. Preferably, the cable 24e is fixed to the wheel 291, making it possible, in particular, to limit or prevent slippage of the cable in contact with the periphery of the wheel.

[0146] Furthermore, the actuator 10 is positioned near the pivot axis A1, the axis of rotation of the actuator being substantially perpendicular to the pivot axis A1. The actuator comprises two rotating shafts, an upper shaft and a lower shaft, each rotating shaft being located at one axial end of the actuator. The cable 24e has one end connected to the upper shaft, extends to the wheel 291 to form the upper strand 24e2, travels approximately half the circumference of the wheel 291, extends to the lower shaft to form the lower strand 24e1, and is connected to said lower shaft. One end of 24e1 is wound around the lower part of the actuator shaft. The ends are wound in opposite directions of rotation: when one end winds, the other unwinds.

[0147] During operation, when the key is pressed, the key return also descends. The pull on the key strip 22 causes the roller and wheel assembly 291 to rotate counterclockwise, thereby pulling on the cable strand 24e1 and unwinding it from the lower shaft, thus driving the actuator, which exerts a resistive force. This embodiment allows for a very high ratio between the angle of rotation of the actuator and the angle of rotation of the key, thereby reducing the torque required by the actuator relative to that required by the key.

[0148] There figure 12represents a seventh embodiment, which will be described by its differences from the first embodiment. The electric motor 10 is located above the upper face K1 of the key, the motor's axis of rotation extending parallel to the pivot axis A1 of the key. The mechanical linkage means comprise a single ribbon that serves as both the actuator ribbon 24 and the key ribbon 22. The assembly means 25 conform to the assembly means of the figures 3a et 3b The connection means 21 conform to the connection means of the figure 9b The upper part of the figure 13 represents two haptic devices conforming to the figure 12 and which are connected to white keys. The two actuators associated with the white keys are located above the keys, are superimposed and offset from each other.

[0149] With reference to the lower part of the figure 13 An eighth embodiment is shown, which will be described by its differences from the previous embodiment. The black keys shown each include a key return R extending under the key to form an "L". In this case, the rotary electric actuator and the mechanical linkage means are located above the upper face K2 of the key return. The actuators associated with the black keys are located under the keys and offset from each other. The connection means are fixed to the front face of the end of the key return. The termination of the key strip is fixed to the distal transverse face of the key return R.

[0150] According to an alternative embodiment visible on the lower part of the figure 13 , the mechanical linkage means include a return pulley 28 disposed between the key return R and the electric motor 10.

[0151] The method of implementation of the figure 13 proposes a specific arrangement to resolve the space constraints posed by the transverse arrangement of actuators whose length is several times the average key width. The figure shows a perspective view of four keys, three of which are associated with actuators and connecting means in an AxR1 configuration, and the black key in the foreground, with an actuator and connecting means in an AxR1PxR1 configuration. The axes of the actuators are parallel to the axis of rotation of the keys, and the connecting means are reduced to a single ribbon and its attachments.

[0152] There figure 14 represents a ninth embodiment which will be described by its differences from the first embodiment. The mechanical linkage means comprise a single ribbon that performs the function of both the actuator ribbon 24 and the key ribbon 22. The assembly means 25 conform to the assembly means of the figures 3a et 3b The ribbon is connected to the key by specific connection means 21. With reference to the figure 15 The connecting means are a connecting piece 21 comprising a body from which two parallel plates extend perpendicularly to the longitudinal direction of the key and perpendicularly to the key's pivot axis, the plates being spaced apart to define a slot. The slot has a width allowing insertion of the key end of the ribbon. The plates each have a hole whose axis extends parallel to the key's pivot axis, the holes being coaxial. Furthermore, the key end includes an opening. The connecting means include a connecting shaft arranged to fit into the holes and the opening. In a particular embodiment, each hole has, according to its cross-section, the shape of an oblong hole so that the connecting shaft can translate laterally.Preferably, the longest dimension of the oblong hole is at least 20% greater than the width (or shortest dimension) of the oblong hole. The oblong shape of the hole allows for play in a direction parallel to the longitudinal direction of the fingerboard.

[0153] With reference to the figure 11 , it illustrates the method of calculating the restraining forces of a traditional or acoustic instrument in order to simulate its dynamics.

[0154] The different phases of the simulation are described below: Initialization: preliminary step in which the geometry and coefficients of the system are initialized; Measurement: the position and acceleration measurements of the key are retrieved at the current time; filtering is applied to reduce measurement noise; the speed of the key is calculated; Geometry update: the position of the system elements is updated with the current-time measurement and the result of solving the equations at the previous time; Calculation of force moments: the moments of the contact forces, weights, forces due to springs, and viscous friction torques are calculated in parallel; Estimation of dry friction torques in the joints and at the contacts between parts: this calculation requires everything described above to be carried out successfully;calculation of the solution of each of the systems of equations which represent on the one hand, the dynamics of the mechanical system that we seek to emulate (keyboard of an acoustic instrument or other), and on the other hand, the dynamics of the haptic interface that we have adopted, in the absence of electrical control. ;

[0155] The invention is described above by way of example. It is understood that a person skilled in the art is able to carry out different embodiments of the invention without departing from the scope of the invention.

Claims

1. A haptic control device (1) for a key of a keyboard equipping an electronic musical instrument intended to reproduce the sensation of use of a similar acoustic musical instrument, said device being arranged to be associated with a key (K) of the electronic musical instrument, which key is pivotably mounted relative to a frame around a pivot axis (A1), the key extending in a longitudinal direction and having an angular travel between a high angular position, called the original position, and a low angular position, called the stop position, said device comprising: - detection means (30) arranged on the key, for detecting information about the dynamic state of the key, - computing means for computing, based on the dynamic information thus detected, an instantaneous resistive force to be exerted on said key in response to said key being depressed, - a rotary electric actuator (10) arranged to produce the resistive force, - mechanical linking means (20) arranged between the rotary electric actuator and the key in order to apply to said key said resistive force, said mechanical linking means comprising at least one element that flexes under pressure and stiffens under traction.

2. The device according to claim 1, wherein the rotary electric actuator has a rotational axis parallel to the pivot axis (A1) of the key.

3. The device according to claim 1, wherein the rotary electric actuator has a rotational axis parallel to the longitudinal direction of the key.

4. The device according to claim 1, wherein the rotary electric actuator has a rotational axis perpendicular to the longitudinal direction of the key and to the rotational axis of the key.

5. The device according to one of claims 1 to 4, wherein the key end is attached to an upper face (K1) or lower face (K3) of the key.

6. The device according to one of claims 1 to 4, wherein the mechanical linking means (20) comprise a key termination which is attached to an upper face (K2) of a key return of the key.

7. The device according to one of the preceding claims, wherein the mechanical linking means (20) comprise an actuator termination and a key termination, the key termination being attached to the key, wherein the ratio between: - the lever arm distance separating the pivot axis (A1) from a key point, where the key termination of the mechanical linking means is attached to the key, and - the lever arm distance separating the rotational axis of the rotary electric actuator from an actuator point, where the actuator termination of the mechanical linking means is attached to the actuator shaft, is at least 10.

8. The device according to one of the preceding claims, wherein the mechanical linking means (20) comprise at least two ribbons that flex under pressure and stiffen under traction.

9. The device according to one of claims 1 to 7, wherein the mechanical linking means (20) comprise at least two cables that flex under pressure and stiffen under traction.

10. The device according to one of claims 1 to 7, wherein the mechanical linking means (20) comprise at least one ribbon that flexes under pressure and stiffens under traction and at least one cable that flexes under pressure and stiffens under traction.

11. The device according to one of claims 1 to 7, wherein the mechanical linking means (20) comprise at least three ribbons that flex under pressure and stiffen under traction.

12. The device according to one of claims 1 to 7, wherein the at least one element that flexes under pressure and stiffens under traction is a cable that flexes under pressure and stiffens under traction or a ribbon that flexes under pressure and stiffens under traction.

13. The device according to one of claims 1 to 7, wherein the mechanical linking means (20) comprise at least two flexible elements comprising at least two ribbons that flex under pressure and stiffen under traction, and a junction part (23) arranged between the two ribbons, said junction part having two opposite and perpendicular ribbon-receiving planes relative to each other to receive the terminations of the two ribbons.

14. The device according to one of claims 1 to 11, wherein the mechanical linking means (20) comprise three flexible elements, two flexible actuator elements (24a, 24b) arranged to be connected to the shaft of the actuator (10), and a flexible key element (22) arranged to be connected to the key, and a junction part arranged between the key element and the two flexible actuator elements, said junction part being arranged to receive the terminations of the three ribbons.

15. The device according to one of claims 1 to 11, wherein the mechanical linking means (20) comprise at least two flexible elements, a flexible actuator element (24) arranged to be connected to the shaft of the actuator (10) and a flexible key element (22) arranged to be connected to the key, and a return part having a pivot axis, said return part being arranged between two flexible elements, said return part being arranged to produce a non-rectilinear trajectory of the mechanical linking means.

16. The device according to one of claims 1 to 7, wherein the mechanical linking means (20) comprise three ribbons, an actuator ribbon (24) arranged to be connected to the shaft of the actuator (10), a first key ribbon (22b), a junction part (23) arranged between the actuator ribbon and the first key ribbon (22b), a second key ribbon (22a) arranged to be connected to the key, and a return part arranged between the first key ribbon (22b) and the second key ribbon (22a) and provided to receive the terminations of the ribbons extending orthogonally.

17. The device according to claim 15 or 16, wherein the return part is an "L"-shaped levered actuation part or a pulley.

18. The device according to one of the preceding claims, comprising an actuator stop (42) arranged at the periphery of the rotation shaft of the actuator or around said rotation shaft, so as to control the angular travel of the rotation shaft of the actuator.

19. The device according to one of the preceding claims, wherein the computing means comprise an actuator module integrating a mechanical model for controlling at least one key of at least one acoustic musical instrument.

20. The device according to one of the preceding claims, wherein the computing means comprise four-quadrant control means for actuating the electric actuator.

21. An electronic musical instrument keyboard with haptic feedback comprising at least one key and at least one haptic control device according to one of the preceding claims, each key being associated with a haptic control device.

22. An electronic musical instrument, for example an electronic piano, comprising at least one haptic device (1) according to one of claims 1 to 20.

23. A method for controlling an electronic musical instrument comprising at least one haptic control device (1) according to one of claims 1 to 20, the method comprising: - a step of detecting a user pressing the key, by the detection means, - a step of real-time control of the actuator to exert a traction force on the key so as to resist the pressing force, or to exert a traction force so as to return the key into its original position.

24. The control method according to the preceding claim, wherein the detection means periodically measure the position and / or the acceleration of the key and then transmit this information to the computing means, the computing means computing the forces generated in a real instrument mechanism from a mathematical model of the dynamics of said mechanism.

Images