FR3024560A1 - METHOD AND INTERFACE OF HAPTICALLY RETURN CONTROL FOR MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a haptic feedback control interface for a motor vehicle comprising a magneto-rheological fluid module (3) comprising a movable element (6), a magnetorheological fluid (7) in contact with the mobile element (6). ) and an application unit (8) of a magnetic field configured to apply a magnetic field to the magnetorheological fluid (7) and to modify the intensity of the applied magnetic field to generate a haptic feedback to the moving user the moving element (6) by modification of the magnetic field applied to the magnetorheological fluid (7), characterized in that it comprises a sound return unit (18) configured to generate a sound return to the user moving the mobile element (6). The invention also relates to a method for controlling a haptic feedback control interface.

Description

The present invention relates to a control interface for a motor vehicle for transmitting a haptic feedback to a user to inform him of the taking into account of a command. The invention also relates to a method of controlling said haptic feedback control interface. The haptic feedback generated for example by the user manipulating a wheel, is generally composed of resistance forces of variable values, creating hard points and bearings, corresponding to different commands for the devices 10 controlled via the interface. The haptic feedback is advantageous by car because it requires little attention from the driver, in particular, it does not require the driver to look away from the road. Interfaces are known having a magnetorheological fluid capable of exerting a braking force on a moving element in the fluid when a magnetic field is applied to the fluid because the viscosity of the magnetorheological fluid changes with the fluid. intensity of the applied magnetic field. The magneto-rheological fluid interfaces can thus generate a haptic feedback to the user manipulating the mobile element immersed in the magnetorheological fluid. One of the advantages of this type of interface is that it generates no parasitic noise when it is handled, unlike conventional mechanical buttons. However, the absence of auditory feedback can affect the quality of perception by the user as well as the handling accuracy perceived by the user. In order to at least partly solve this drawback, the subject of the present invention is a haptic feedback control interface for a motor vehicle comprising a magneto-rheological fluid module comprising a mobile element, a magnetorheological fluid in contact with the movable member and a magnetic field applying unit configured to apply a magnetic field to the magnetorheological fluid and to modify the intensity of the applied magnetic field to generate a haptic feedback to the user moving the movable member by modifying the magnetic field applied to the magnetorheological fluid, characterized in that it comprises a sound return unit configured to generate a sound return to the user moving the movable element. It is thus possible to improve the quality and the precision of handling perceived by the user with a great freedom of choice for the sound accompaniment, -2- allowing to deliver singular performances to the existing solutions because it is possible to control the sound feedback without be dependent on mechanical elements. The sound can be personalized and its signature can for example allow the identification of the car manufacturer. The volume of the sound return can be adapted to the sound environment of the passenger compartment, for example by being controlled according to a microphone arranged in the passenger compartment. In addition, the possibility is left to the user to completely or partially suppress the generation of sound returns or to modify the sound returns generated. According to one or more characteristics of the control interface, taken alone or in combination, the sound return unit is configured to generate a sound return depending on the position and / or the position variation and / or the speed and / or the speed variation of the movable element and / or the acceleration and / or the variation of the acceleration and / or the direction of movement of the movable element. Indeed, there is a certain correlation between the auditory feedback emitted during the manipulation of conventional mechanical buttons and the manner in which the button is moved. Thus, by generating a sound return whose parameters are variable according to the manner in which the movable element is displaced, the illusion of the manipulation of a conventional mechanical knob is enhanced, the sound return unit is configured to generate a sound return associated with a haptic feedback. The control interface thus has functionalities close to conventional mechanical interfaces at the acoustic and haptic level. The control interface comprises a position and / or velocity and / or acceleration and / or force sensor configured to determine position and / or position variation and / or velocity and / or variation. speed and / or acceleration and / or acceleration variation and / or the direction of movement of the movable member and / or the braking force and / or a variation of the braking force exerted on the movable element, the position sensor and / or speed and / or acceleration and / or effort being connected to the sound return unit. The subject of the invention is also a method for controlling a haptic feedback control interface as described above, characterized in that a sound return is transmitted to the user moving the mobile element. According to one or more characteristics of the control method, taken alone or in combination, the sound return is a function of the position and / or the position variation and / or the speed and / or the speed variation of the movable element and / or the acceleration and / or the variation of the acceleration and / or the direction of movement of the movable element, the sound return comprises at least one variable parameter chosen from among the number of sound patterns, the envelope, the frequencies and harmonics, the intensity of the volume and the duration, the sound return is defined by a table of correspondences and / or by a rule, a sound return is emitted as the displacement of the movable element is distinct from a null displacement, one emits a sound return associated with a haptic feedback, the sound feedback is a function of the braking force exerted on the mobile element and / or the magnetic field exerted on the magnetorheological fluid, the sound return is issued as a function of at least u characteristic of the haptic feedback signal. The sound return can thus be synchronized with the haptic feedback generated, so as to simulate a particular position of the movable element, such as an indexing position or a particular position on an indexing ramp, such as a midpoint, a stop , a particular point of a function related to this ramp, ensuring the coherence of the haptic and sound returns, a sound return is emitted when a variation of the applied magnetic field and / or the braking force generated on a predetermined displacement is greater than a predetermined threshold, a sound return is emitted when crossing a maximum or a minimum of the applied magnetic field and / or the braking force generated, a sound return is emitted during a rising edge the applied magnetic field and / or the braking force generated and / or at a falling edge of the applied magnetic field and / or the braking force generated, an audible feedback is emitted when the magnetic field applied and / or the braking force generated is within a predefined range, a sound return is emitted before or after the generation of the associated haptic feedback, the sound return comprises a predefined number of sound patterns lower, higher or equal to the number of haptic patterns of the associated haptic feedback.

Other features and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended drawing in which Figure 1 is a single schematic view of an exemplary embodiment of the invention. a haptic feedback control interface.

FIG. 1 represents a haptic feedback control interface 1 for a motor vehicle, for example mounted in the dashboard or in a central console of the vehicle, for controlling on-board vehicle systems such as the air-conditioning system, radio system, telephone, ventilation or navigation.

The control interface 1 comprises a magneto-rheological fluid module 3 and a sound return unit 18. The magnetorheological fluid module 3 comprises a mobile element 6, a magnetorheological fluid 7 in contact with the movable element 6 and an application unit 8 of a magnetic field configured to apply a magnetic field to the magnetorheological fluid 7 and to modify the intensity of the applied magnetic field. The movable element 6 is for example mobile in rotation or in translation. The application unit 8 of a magnetic field is connected to the sound return unit 18.

The magnetorheological fluid module 3 may comprise a gripping element 5, integral with the movable element 6, that is to say rigidly connected to the movable element 6. The gripping element 5 is for example made of material with the movable member 6 or clipped on the movable member 6 or fixed by pin or by any other known fastening means. Alternatively, the gripping element 5 can be coupled to the movable element 6 via a gear system, chains, belts or any other mechanical means for ensuring a coupling between the gripping element 5 and the movable element 6.

A haptic feedback is generated to the user who moves the movable element 6 via the gripping element 5, by modifying the magnetic field applied to the magnetorheological fluid 7. The term "haptic" refers to a return by touch, such as that the braking force exerted on the movable member 6. In fact, the magnetorheological fluid 7 has the property that its viscosity varies under the effect of a variable magnetic field. Thus, the friction force induced by the magnetorheological fluid 7 is low when no magnetic field is applied and becomes more and more important when the intensity of the magnetic field increases. Magnetorheological fluids can thus be used as magneto-rheological brakes. For example, the application of a niche-shaped intensity makes it possible to create hard points generating indexing points for which the intensity is important. The haptic feedback comprises one or more haptic patterns defined by a signal representing the generated braking force or the magnetic field applied to the magnetorheological fluid 7, as a function of the position and / or the variation of position and / or the speed and / or speed variation and / or acceleration and / or a variation of the acceleration and / or direction of movement of the movable member 6. The position of the movable member 6 is for example the angular position for a rotating movable element 6. The haptic pattern has for example a so-called simple shape: linear, square, half-sine, triangle, etc. or a so-called complex shape comprising a combination of simple shapes or a curve. Different haptic patterns can thus be obtained. For example, the intensity of the magnetic field may have a slot shape in which the intensity is zero or low except at the indexing positions where this intensity is strong so as to generate a significant braking force generating points d 'indexing. Other haptic patterns are also possible, for example triangular or sawtooth profiles distributed around the indexing positions, so that they are perceived as a progressive hard point to overcome. The haptic feedback generated with the rotation of the mobile element 6 can for example index the navigation in a list of a drop-down menu displayed on a display screen, the rotation of the rotary element 6 controlling the scrolling of the list, the haptic feedback being generated at each indexing position for which a cursor points a choice from the drop-down menu.

The haptic patterns can be stored for example in the application unit 8 of a magnetic field or can be determined according to the position and / or the variation of position and / or the speed and / or the variation of speed and / or acceleration and / or variation of the acceleration and / or direction of movement of the movable element 6.

The sound return unit 18 is configured to generate a sound return, such as a sound simulating friction or mechanical indexing. It is thus possible to improve the quality and the precision of manipulation perceived by the user with a great freedom of choice for the sound accompaniment, making it possible to deliver singular performances to the existing solutions because it is possible to control the sound return without being dependent on mechanical elements. The sound can be personalized and its signature can for example allow the identification of the car manufacturer. The volume of the sound return can be adapted to the sound environment of the passenger compartment, for example by being controlled according to a microphone arranged in the passenger compartment. In addition, the possibility is left to the user to completely or partially suppress the generation of sound returns or to modify the sound returns generated. The sound returns can be memorized in the sound return unit 18. It is also possible that the sound returns are variable depending on the position and / or the variation of position and / or the speed and / or variation speed and / or acceleration and / or variation of the acceleration and / or the direction of displacement of the movable member 6. Indeed, there is a certain correlation between the auditory feedback emitted during the manipulation of classic mechanical buttons and the way in which the button is moved. Thus, by generating a sound return whose parameters are variable according to the manner in which the movable element is displaced, the illusion of the manipulation of a conventional mechanical knob is enhanced. For example, the sound return of a rotating mobile element 6 may be a function of the speed of rotation or the value of the torque of a mobile element 6 rotating. For this, the sound return unit 18 is connected to a position sensor and / or speed and / or acceleration 21 of the control interface 1. The sensor 21 can also be connected to the application unit 8 of a magnetic field for controlling the application unit 8 of a magnetic field to the magnetorheological fluid 7 generating a desired haptic feedback.

The position and / or speed and / or acceleration sensor 21 may comprise, for example, a set of contacts and a brush in contact successively with some of the contacts during the displacement of the mobile element 6. The sensor may be an encoder optical system comprising one or more optical forks or a piezoelectric device. The acceleration sensor may be an accelerometer. The sensor 21 may be located at different locations near the movable element 6 and in particular on the side of the gripping element 5. The sound return comprises for example at least one variable parameter chosen from the number of sound patterns. sound, envelope, frequencies and harmonics, volume intensity and duration. For example, it is expected that the sound return has several sound patterns, all or part of which can be suppressed or replaced or modulated, for example in intensity and / or in duration according to the moving speed of the mobile element 6. The sound return can be defined by a table of correspondences. The 20 correspondence table matches a sound return with a value or range of value of the angular position of the speed and / or acceleration and / or direction of movement of the movable member 6. The sound return can also be defined by a rule for all values or ranges of position and / or position variation value and / or speed and / or speed variation and / or acceleration and / or the acceleration variation and / or the direction of movement of the movable element 6. The rule can be a law or an algorithm. For example, the rule can be an equation defining the intensity of the volume of a sound. This function can be a proportional or variable relationship. According to an exemplary embodiment, a sound return is emitted as long as the displacement of the movable element 6 is distinct from a zero displacement, for example as long as the speed of the movable element 6 is not zero. The emitted sound return can thus for example simulate the friction of an index on an indexing ramp as soon as one starts to turn the mobile element 6. The sound return can be the only sensory feedback perceived by the user. In another embodiment, the sound return is associated with a haptic feedback. The control interface 1 thus has functionalities close to conventional mechanical interfaces at the acoustic and haptic level. The sound return can also be a function of the haptic feedback. For example, it is defined by a look-up table or a rule, matching a sound return with a value or value range of the braking forces exerted or the applied magnetic field. These values may be transmitted by the unit for applying a magnetic field 8 to the sound return unit 18 or may be received from a force sensor of the interface 1, such as a torque sensor. . It can further be provided that the sound return is output based on at least one characteristic of the haptic feedback signal. The sound return can thus be synchronized with the generated haptic feedback, so as to simulate a particular position of the movable element 6, such as an indexing position or a particular position on an indexing ramp, such as a midpoint, a stop, a particular point of a function related to this ramp, ensuring the coherence of feedback 20 haptic and sound. According to a first example, a sound return is emitted when a variation of the applied magnetic field and / or the braking force generated on a predetermined displacement is greater than a predetermined threshold. For example, a sound return is emitted for a decrease of the braking force generated to its lowest value. Several thresholds may be predetermined in relation to magnetic field variations or braking forces observed. According to a second example, a sound return is emitted when crossing a maximum or a minimum of the applied magnetic field and / or the braking force generated. A sound return can thus be emitted to simulate an abutment force corresponding to a maximum braking force. Alternatively or additionally, a sound return may be emitted to simulate an indexing force corresponding to a minimum braking force, which may, for example, be perceived at the moment of maximum relaxation of an elastic index which is positioned in a hollow. - an indexing ramp. According to a third example, a sound return is emitted during a rising edge of the applied magnetic field and / or the braking force generated and / or during a falling edge of the applied magnetic field and / or the force generated braking. A sound return can thus be emitted to simulate a corresponding effort, on a conventional rotary-type mechanical knob, to catch up games or to compress the turns of a spring or to decompress the turns once the maximum effort has been made. Braking crossed. According to a fourth example, a sound return is emitted when the magnetic field applied and / or the braking force generated is within a predefined range. The sound returns emitted in particular when crossing a maximum or a minimum, a rising edge or a falling edge, or as long as the displacement of the mobile element 6 is non-zero, reinforces the illusion of a mechanical knob of quality. These sound returns can be distinct from each other. It can further be provided that the sound return is issued before the generation of the associated haptic feedback. A sound return transmitted before, can be emitted simultaneously with a previous haptic feedback. A sound return transmitted at the same time as a previous haptic feedback 20 may allow the user, for example, to anticipate a haptic feedback to come, for example during the rotation of a movable member 6 rotated in the same direction. The sound return emitted before can also be emitted while no haptic feedback is generated. According to another example, a sound return is emitted after the generation of the associated haptic feedback, while no haptic feedback is generated. This sound feedback can be used to simulate some mechanical buttons for which a stop sound "click" is issued after the button has reached a stop. This case applies, for example, to mechanical knobs having high friction forces requiring a longer time of catching the games. It is also possible that the sound return comprises a predefined number of sound patterns, lower, greater or equal to the number of haptic patterns of the associated haptic feedback. For example, a sound pattern is issued only with a first haptic pattern of a series of haptic patterns. In another example, a sound pattern is emitted only with a predefined number of first haptic patterns, the following haptic patterns not being associated with the emission of sound patterns. In another example, a sound pattern is issued only with a predefined number of first haptic patterns and last haptic patterns. According to another example, no sound pattern is emitted with one or more first haptic patterns and the following haptic patterns are associated with the emission of a sound pattern. The overall volume of the sound return can of course be adjusted or deleted by the user, for example by means of an interactive menu, a key or a potentiometer. It is also possible that the overall volume of the sound return is adjusted automatically according to the volume of the radio or other equipment of the motor vehicle such as the telephone so as not to disturb the listening. Also, alert type sound returns could be stored for example to alert the user of improper handling of the control interface 1 or a possible failure of the control with the magnetorheological fluid or leakage It can also be provided that the sound return is emitted by the sound return unit 18 in a zone of the control interface 1, for example close to the gripping element 5, in order to simulate that the sound comes from the magnetorheological fluid module 3. FIG. 1 shows an exemplary embodiment of a rotating mobile element 6. The magneto-rheological fluid module 3 comprises a base 9 having a generally cylindrical shape extending along an axis of rotation Z of the module 3, closed at one of its ends by a fixed central axis 10 oriented along the axis. Z, defining an annular cavity 11. The movable member 6 is movably mounted on the fixed base 9, about the axis of rotation Z. The cavity 11 is intended to receive on the one hand the magnetoid fluid. rheological 7 and secondly an end of the movable member 6. The movable member 6 is then partially immersed in the magnetorheological fluid 7. The base 9 also has an annular housing 12 which at least partially surrounds the cavity 11.

The annular housing 12 receives one or more coil (s) which, with its (their) power supply (s) (not shown), forms the application unit 8 of a magnetic field on the magnetorheological fluid 7. The magnetic field created by a coil being proportional to the current flowing through it, the intensity of the magnetic field created in the center of the coil can be varied by varying the power supply of the coil. The variation of the intensity of the magnetic field applied to the magnetorheological fluid 7 makes it possible to vary the viscosity of the fluid and thus the friction force exerted by the fluid. It is thus possible to vary the force with which the movable member 6 can be rotated to generate a specific haptic feedback to the user handling the movable member 6. In addition, the friction force applied by the magnetorheological fluid 7 on the movable element 6 varies as a function of the fluid surface in contact with the movable element 6. Thus, the end of the movable element 6 in contact with the magnetorheological fluid 7 may comprise several end walls 13 cylindrical and concentric, extending along the axis of rotation Z, and facing complementary walls extending from the bottom of the cavity 11. For example, the base 9 comprises a complementary wall 14, coming s to interpose between the end walls 13 of the movable element 6 to increase the facing surfaces between the movable element 6 and the base 9 and thus increase the force torque that can be exerted on the element mobile 6 with a e given power supply. The magnetorheological fluid module 3 further comprises seals 16, for example interposed on the one hand, between the cavity 11 and a cover 15 closing the cavity 11 and, on the other hand, between the cavity 11 and a shoulder of the movable member 6. The seals 16 seal to prevent leakage of the magnetorheological fluid 7 out of the cavity 11. The cover 15 also includes a housing receiving a bearing or ball bearing 17 which provides the rotational connection between the base 9 and the movable element 6.

Claims (18)

REVENDICATIONS1. A haptic feedback control interface for a motor vehicle comprising a magneto-rheological fluid module (3) comprising a movable element (6), a magnetorheological fluid (7) in contact with the movable element (6) and a magnetometer unit (6). applying (8) a magnetic field configured to apply a magnetic field to the magnetorheological fluid (7) and to modify the intensity of the applied magnetic field to generate a haptic feedback to the user moving the movable member ( 6) by modifying the magnetic field applied to the magnetorheological fluid (7), characterized in that it comprises a sound return unit (18) configured to generate a sound return to the user moving the movable member (6) . Control interface according to the preceding claim, characterized in that the sound return unit (18) is configured to generate an audible feedback as a function of the position and / or the variation of position and / or the speed and / or the variation in speed of the movable element (6) and / or the acceleration and / or the variation of the acceleration and / or the direction of movement of the movable element (6). Control interface according to one of the preceding claims, characterized in that the sound return unit (18) is configured to generate a sound return associated with a haptic feedback. 4. Control interface according to one of the preceding claims, characterized in that it comprises a position sensor and / or speed and / or acceleration and / or effort (21) configured to determine the position and / or a variation of position and / or the speed and / or a variation of speed and / or an acceleration and / or an acceleration variation and / or the direction of movement of the movable element and / or the effort of braking and / or a variation of the braking force exerted on the movable element, the position and / or velocity and / or acceleration and / or effort sensor (21) being connected to the braking unit. sound return (18). 5. A method of controlling a haptic feedback control interface according to one of the preceding claims, characterized in that it emits a sound feedback to the user moving the movable member (6). 6. Control method according to the preceding claim, characterized in that the sound return is a function of the position and / or the position variation and / or the speed and / or the speed variation of the movable element (6) and / or the acceleration and / or -13- the variation of the acceleration and / or the direction of movement of the movable element (6). 7. Control method according to the preceding claim, characterized in that the sound return comprises at least one variable parameter selected from the number of sound patterns, the envelope, the frequencies and harmonics, the volume intensity and the duration. 8. Control method according to one of claims 6 or 7, characterized in that the sound return is defined by a table of correspondence and / or a rule. 9. Control method according to one of claims 5 to 8, characterized in that a sound return is issued as the displacement of the movable member (6) is distinct from a zero displacement. 10. Control method according to one of claims 5 to 9, characterized in that emits a sound return associated with a haptic feedback. 11. Control method according to the preceding claim, characterized in that the sound return is a function of the braking force exerted on the movable element (6) and / or the magnetic field exerted on the magnetorheological fluid (7). . 12. Control method according to one of claims 10 or 11, characterized in that the sound return is transmitted as a function of at least one characteristic of the haptic feedback signal. 13. Control method according to the preceding claim, characterized in that a sound return is issued when a variation of the applied magnetic field and / or the braking force generated on a predetermined displacement is greater than a predetermined threshold. 14. Control method according to one of claims 12 or 13, characterized in that a sound return is issued when crossing a maximum or a minimum of the applied magnetic field and / or the braking force generated. 15. Control method according to one of claims 12 to 14, characterized in that a sound return is emitted during a rising edge of the applied magnetic field and / or braking force generated and / or during a falling edge of the applied magnetic field and / or braking force generated. 16. Control method according to one of claims 12 to 15, characterized in that a sound return is emitted when the applied magnetic field and / or braking force generated is within a predefined range. 17. Control method according to one of claims 12 to 16, characterized in that a sound return is issued before or after the generation of the associated haptic feedback. 18. Control method according to one of claims 12 to 17, characterized in that the sound return comprises a predefined number of sound patterns less than, greater than or equal to the number of haptic patterns of the associated haptic feedback.