determination and avoidance of excessive excursion of the internal mass of the transducer

Abstract

A method for determining and mitigating excessive excursion of an inner mass of an under-damped electromechanical transducer can include determining, based on an estimated displacement signal, an estimated excessive excursion of the inner mass in response to an electrical playback signal, and limiting, based on the estimated excessive excursion, an electrical drive signal derived from the electrical playback signal and used to drive the electromechanical transducer so as to mitigate the excessive excursion of the inner mass.

Description

Technical Field

[0001] This disclosure generally relates to methods, apparatus, or implementations for haptic devices. In particular, the embodiments described herein may disclose systems and methods for detecting and preventing nonlinear deviations in haptic actuators. Background Technology

[0002] Vibrational haptic transducers, such as linear resonant actuators (LRAs), are widely used in portable devices such as mobile phones to generate vibrational feedback to users. Various forms of vibrational haptic feedback create different tactile sensations on the user's skin and are playing an increasingly important role in human-computer interaction in modern devices.

[0003] An LRA can be modeled as a mass-spring electromechanical vibration system. When driven by a properly designed or controlled drive signal, an LRA can generate certain desired forms of vibration. For example, a sharp and distinct vibration pattern on a user's finger can be used to create a sensation that mimics the click of a mechanical button. This distinct vibration can then be used as a virtual switch to replace a mechanical button.

[0004] When a haptic transducer is driven by an electrical signal, the transducer's internal mass may collide with its outer casing. This can have undesirable effects, including permanent damage to the transducer, alterations to transducer characteristics, unwanted audio artifacts (e.g., a loud "click" sound when the internal mass strikes the casing), and / or distorted haptic effects. Typically, such collisions can be avoided by playing back only "known" content in the form of pre-stored waveforms to the haptic transducer. However, such collisions can occur if the playback condition changes or if unknown content is played back (e.g., with audio-to-haptic playback streaming). While limiting the playback level of unknown content can mitigate or eliminate such collisions, such limitations may weaken the haptic effect.

[0005] Manufacturers of haptic actuators typically specify a maximum signal voltage (e.g., the maximum number of voltages at a given frequency, root mean square) to minimize or eliminate damage. From this voltage limit, offset limits in terms of displacement or distance can be inferred. However, for unknown playback content, it can be difficult to comply with the manufacturer's inferred offset limits for under-damped devices, such as haptic sensors.

[0006] Methods and systems exist for limiting speaker offset, but they are generally ineffective for underdamped devices. In such methods, attenuation is typically applied directly to the drive voltage signal applied to the speaker. However, since haptic transducers are typically underdamped (i.e., have a higher Q factor compared to the speaker), directly applying a limiting voltage signal to the drive voltage may not control the mass block position to limit the offset within a predetermined threshold.

[0007] Therefore, other methods may be needed to prevent excessive offset of tactile transducers and other underdamped devices. Summary of the Invention

[0008] Based on the teachings of this disclosure, the disadvantages and problems associated with existing methods for avoiding excessive offset in tactile transducers can be reduced or eliminated.

[0009] According to embodiments of this disclosure, a method for determining and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer may include converting an electrical playback signal into an estimated displacement signal based on an estimated displacement signal, determining an estimated excessive offset of the internal mass block in response to the electrical playback signal, and deriving an electrical drive signal from the electrical playback signal based on the estimated excessive offset limit and using it to drive the electromechanical transducer in order to mitigate the excessive offset of the internal mass block.

[0010] According to these and other embodiments of the present disclosure, a method for determining and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer may include: for each of a set of known playback waveforms, determining a transition for each waveform that minimizes excessive offset of the internal mass block based on playback conditions, storing the transition in a memory, and applying a corresponding transition associated with the particular known waveform and based on the playback conditions during the runtime and playback of the particular known waveform.

[0011] According to these and other embodiments of the present disclosure, a system for determining and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer may include: an electrical drive-to-excursion model and an excursion limiter, wherein the electrical drive-to-excursion model is configured to convert an electrical playback signal into an estimated displacement signal, and the excursion limiter is configured to determine an estimated excessive offset of the internal mass block in response to the electrical playback signal based on the estimated displacement signal, and to limit an electrical drive signal derived from the electrical playback signal based on the estimated excessive offset, and to drive the electromechanical transducer to mitigate the excessive offset of the internal mass block.

[0012] According to these and other embodiments of the present disclosure, a system for determining and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer includes a memory and a controller. The memory is configured to store a transition for each waveform in a set of known playback waveforms that minimizes excessive offset of the internal mass block based on playback conditions. The controller is configured to apply a corresponding transition associated with a particular known waveform and based on playback conditions during the runtime and playback of a particular known waveform.

[0013] The technical advantages of this disclosure will be apparent to those skilled in the art from the accompanying drawings, description, and claims. The objects and advantages of the embodiments will be realized and accomplished, at least by means of the elements, features, and combinations particularly pointed out in the claims.

[0014] It should be understood that the foregoing general description and the following detailed description are illustrative and explanatory, and not limiting of the claims set forth in this disclosure. Attached Figure Description

[0015] A more complete understanding of this embodiment and its advantages can be obtained by referring to the following description taken in conjunction with the accompanying drawings, wherein similar reference numerals indicate similar features, and wherein:

[0016] Figure 1 illustrates an example of a vibration-tactile system in a device according to an embodiment of the present disclosure;

[0017] Figure 2 Selected components of an example controller, which can be used to implement the controller depicted in FIG1, are shown according to embodiments of the present disclosure;

[0018] Figure 3 Selected components of an example offset limiter according to an embodiment of the present disclosure are shown;

[0019] Figure 4 Selected components of another example controller, according to embodiments of the present disclosure, are shown that can be used to implement the controller depicted in FIG1; and

[0020] Figure 5 Selected components of another example controller, which can be used to implement the controller depicted in FIG1, are shown according to an embodiment of the present disclosure. Detailed Implementation

[0021] Figure 1 illustrates an example of a vibration-tactile system in a device 100 according to an embodiment of the present disclosure. As shown in Figure 1, the device 100 may include a controller 101 configured to control a drive signal V applied to an amplifier 102. DRV The controller 101 can be triggered by a flip-flop to output a drive signal V. DRVThe trigger may include, for example, a pressure or force sensor on the screen or virtual button of device 100.

[0022] Controller 101 may include any system, device, or apparatus configured to interpret and / or execute program instructions and / or process data, and may include, but is not limited to, a microprocessor, microcontroller, digital signal processor (DSP), application-specific integrated circuit (ASIC), or any other digital or analog circuit configured to understand and / or execute program instructions and / or process data. In some embodiments, controller 101 may interpret and / or execute program instructions and / or process data stored in a memory or other computer-readable medium (not explicitly shown) communicatively coupled to controller 101. In some embodiments, controller 101 may be configured to determine a drive signal V for driving vibration actuator 103. DRV Whether this will cause excessive offset of the moving mass block inside the vibration actuator 103, and apply displacement-based constraints to minimize or eliminate excessive offset, as described in more detail below.

[0023] Amplifier 102 can then be based on the drive signal V DRV Drive the vibration actuator (e.g., a tactile transducer or other underdamped transducer) 103. Amplifier 102 can be any system, device, or apparatus configured to amplify the signal received from controller 101 and transmit the amplified signal (e.g., to vibration actuator 103).

[0024] As described above, controller 101 can be configured to determine a drive signal V for driving vibration actuator 103. DRV Whether this will cause excessive offset of the internal moving mass block of the vibration actuator 103, and apply displacement-based constraints to minimize or eliminate excessive offset. To this end, the controller 101 can apply a displacement-based transformation to the original electrical drive signal to generate the drive signal V. DRV It is used to drive the vibration actuator 103 via amplifier 102.

[0025] Figure 2 Selected components of an example controller 101A, which can be used to implement the controller 101 depicted in FIG1, according to embodiments of the present disclosure, are shown. Figure 2 As shown, the controller 101A may include an electric drive-to-excursion model 202, an offset limiter 204, and an excursion-to-electrical drive model 206.

[0026] The electric drive-to-excursion model 202 may include an electric drive-to-excursion transfer function, such that when the electric drive-to-excursion transfer function is applied to the original drive signal V representing the drive signal applied to the vibration actuator 103... DRV When ′, if the original drive signal V DRV If a displacement D is hypothetically applied to vibration actuator 103 (or amplifier 102, which in turn drives vibration actuator 103), the result is an estimated displacement D of vibration actuator 103. EST For example, the electric drive to offset model 202 can be based on characteristics derived from the testing and / or characterization of the vibration actuator 103 in response to drive voltages of various frequencies and / or amplitudes.

[0027] Offset limiter 204 can apply an offset threshold (e.g., the maximum safe displacement of the internal mass block of vibration actuator 103) to the estimated displacement D. EST In order to generate a restricted displacement D LIM . Figure 3 Selected components of an example offset limiter 204 according to an embodiment of this disclosure are shown. Figure 3 As shown, the offset limiter 204 may include a look-ahead delay element 302, a gain generator 304, a gain smoother 306, and a gain element 308.

[0028] The look-ahead delay element 302 may include elements configured to move toward the estimated displacement D EST Add signal delay to generate look-ahead displacement D LOOKAHEAD Any suitable system, device, or apparatus. This delay and look-ahead may be necessary to detect potential offset threshold violations and to provide signal attenuation before such violations occur.

[0029] Gain generator 304 may include being configured to generate look-ahead displacement D based on an offset threshold. LOOKAHEAD Multiplicative attenuation gain G LIM This is applicable to any suitable system, device, or apparatus that keeps the displacement of the internal mass block of the vibration actuator 103 below such offset threshold. Gain smoother 306 can generate a smoothing gain GSMOOTH based on smoothing parameters (e.g., attack, hold, release) and / or filtering applications. Gain element 308 can apply the smoothing gain GSMOOTH to the look-ahead displacement D. LOOKAHEAD To generate a restricted displacement D LIM .

[0030] Turn to Figure 2 The offset to the electric drive model 206 can include an excursion-to-electrical drive transfer function, which can be the inverse transfer function of the electric drive to the offset model 202. Therefore, when the excursion-to-electrical drive transfer function of the electric drive model 206 is applied to a displacement signal representing the offset of the internal mass block of the vibration actuator 103, the result is a drive signal V. DRV When applied to the vibration actuator 103, this drive signal V DRV Keep the displacement of the internal mass block within the offset threshold.

[0031] Figure 4 Selected components of an example controller 101B, which can be used to implement the controller 101 depicted in FIG1, according to embodiments of the present disclosure, are shown. Figure 4 As shown, the controller 101B may include a look-ahead delay element 402, an electric drive to offset model 404, an offset to gain function 406, and a gain element 408.

[0032] Look-ahead delay element 402 may include elements configured to direct the original drive signal V DRV Add signal delay to generate look-ahead drive signal V LOOKAHEAD Any suitable system, device, or apparatus. This delay and look-ahead may be necessary to detect offset threshold violations and provide signal attenuation before the violation occurs.

[0033] The electric drive to offset model 404 may include an electric drive to offset transfer function, such that when the electric drive to offset transfer function is applied to the original drive signal V representing the drive signal applied to the vibration actuator 103... DRV When ′, if the original drive signal V DRV If a displacement D is hypothetically applied to vibration actuator 103 (or amplifier 102, which in turn drives vibration actuator 103), the result is an estimated displacement D of vibration actuator 103. EST For example, the electric drive-to-offset model 202 can be based on characteristics derived from testing and / or characterization of the vibration actuator 103 in response to drive voltages of various frequencies and / or amplitudes. In some embodiments, the electric drive-to-offset model 404 can be... Figure 2 The electric drive to offset model 202 described in the paper is similar to or the same.

[0034] The offset gain function 406 may include functions configured to generate a look-ahead drive signal V based on an offset threshold. LOOKAHEADMultiplicative attenuation gain G LIM This is applicable to any suitable system, device, or apparatus that keeps the displacement of the internal mass block of the vibration actuator 103 below such offset threshold. The gain element 408 can increase the gain G. LIM Applied to the look-ahead drive signal V LOOKAHEAD To generate the driving signal V DRV。

[0035] Figure 5 Selected components of an example controller 101C, according to embodiments of the present disclosure, that can be used to implement the controller 101 depicted in FIG1. ​​For example... Figure 5 As shown, the controller 101C may include a converter 502 and a converter lookup table 504.

[0036] In controller 101C, an offline process can be used to analyze known playback content offline and determine multiple electric drive-to-electric drive transitions for each known playback waveform based on different playback conditions. Examples of playback conditions may include temperature, features that enable and disable device 100, and any other suitable conditions. Such transitions can be stored in lookup table 504, and during the operation of device 100, controller 101C can detect playback conditions, select the transition 502 associated with the known waveform being played back from lookup table 504, and apply this transition to the original drive signal V. DRV ′, so as to generate drive signal V DRV These conversions vary in complexity, ranging from simple conversions (such as gain) to complex conversions (such as those that manipulate frequency content and / or dynamic range).

[0037] As used herein, when two or more elements are referred to as “coupled” to each other, the term indicates that the two or more elements are in electronic or mechanical communication (where applicable), whether indirectly or directly connected, with or without intervening elements.

[0038] This disclosure covers all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments herein that will be understood by those skilled in the art. Similarly, where appropriate, the appended claims cover all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments herein that will be understood by those skilled in the art. Furthermore, in the appended claims, references to a device, system, or component adapted to, arranged to, capable of, configured to, enabled to, operable to, or operable to perform a particular function include that device, system, or component, whether or not it or the particular function is activated, turned on, or unlocked, as long as that device, system, or component is so adapted, arranged, capable of, configured to, enabled to, operable to, or operable. Therefore, modifications, additions, or omissions may be made to the systems, devices, and methods described herein without departing from the scope of this disclosure. For example, components of a system and device may be integrated or separate. Furthermore, the operation of the systems and devices disclosed herein may be performed by more, fewer, or other components, and the described methods may include more, fewer, or other steps. Furthermore, the steps may be performed in any suitable order. As used in this document, “each” means each member of a set or each member of a subset of a set.

[0039] Although exemplary embodiments are shown in the accompanying drawings and described below, the principles of this disclosure can be implemented using any number of techniques, whether currently known or not. This disclosure should not be limited in any way to the exemplary embodiments and techniques shown in the drawings and described above.

[0040] Unless otherwise specified, the items depicted in the drawings are not necessarily drawn to scale.

[0041] All examples and conditional language listed herein are intended for educational purposes to aid the reader in understanding the concepts contributed by the inventors to further advance the art, and are not to be construed as being limited to these specifically listed examples and conditions. Although embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and modifications can be made thereto without departing from the spirit and scope of the disclosure.

[0042] While specific advantages have been listed above, various embodiments may include some, none, or all of the listed advantages. Furthermore, other technical advantages will become apparent to those skilled in the art upon review of the foregoing figures and description.

[0043] In order to help the Patent Office and any reader of any patent issued under this application interpret the claims appended to this application, the applicants wish to note that they do not intend for any appended claim or claim element to invoke 35 U.S.SC §112(f) unless “means for…” or “steps for…” is expressly used in a particular claim.

Claims

1. A method for identifying and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer, the method comprising: Convert the electrical playback signal into an estimated displacement signal; Based on the estimated displacement signal, the estimated excessive offset of the internal mass block in response to the electrical playback signal is determined; as well as Based on the estimated excessive offset, the electrical drive signal derived from the electrical playback signal and used to drive the electromechanical transducer is limited in order to mitigate the excessive offset of the internal mass block. The limiting of the electric drive signal includes: Generate multiplicative attenuation gain based on offset threshold; The multiplicative attenuation gain is applied to the displacement signal to generate a constrained displacement signal; and The restricted displacement signal is converted into the electric drive signal.

2. A system for identifying and mitigating excessive offset of the internal mass block of an underdamped electromechanical transducer, the system comprising: An electric drive-to-offset model is configured to convert an electrically replay signal into an estimated displacement signal. as well as Offset limiter, the offset limiter being configured to: The estimated excessive offset of the internal mass block in response to the electrical playback signal is determined based on the estimated displacement signal. as well as Based on the estimated excessive offset, the electrical drive signal derived from the electrical playback signal and used to drive the electromechanical transducer is limited in order to mitigate the excessive offset of the internal mass block. The limiting of the electric drive signal includes: Generate multiplicative attenuation gain based on offset threshold; The multiplicative attenuation gain is applied to the displacement signal to generate a constrained displacement signal; and The restricted displacement signal is converted into the electric drive signal.

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