Electromagnetic tactile feedback device and feedback method

Abstract

The invention discloses an electromagnetic tactile feedback device and a feedback method. In the device, an electromagnetic coil is accommodated in a hollow table part; the tactile needle head comprises a hollow accommodating part adapted to enter the through hole and a needle-shaped piece extending upwards from the hollow accommodating part, a magnet is accommodated in the hollow accommodating part, and a plurality of limiting pieces are sequentially arranged on the needle-shaped piece in a penetrating manner at intervals; the flexible valve lock is transversely fixed in the through hole, the flexible valve lock comprises a ring piece and a plurality of flexible teeth extending from the inner wall of the ring piece to the center, and the flexible teeth are bent when acting with the limiting piece, so that after the limiting piece crosses the flexible teeth, the flexible teeth restore to the original shape and play a supporting role; the linear bearing is arranged in the pipe fitting, the needle-shaped piece penetrates through the linear bearing so as to limit the movement of the linear bearing in the axial position to move up and down, the electromagnetic coil is powered on to generate a magnetic field, the magnetic field and the magnet act to generate electromagnetic force, and therefore the multiple limiting pieces act on the flexible valve lock in sequence to generate multi-stage tactile feedback.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic tactile feedback in human-computer interaction, and in particular to an electromagnetic tactile feedback device and a feedback method. Background Art

[0002] Touch is an important means of human perception and communication. It is one of the five basic human senses. It transmits information through receptors and nerves on the skin, allowing us to perceive and understand the objects, surfaces and environment around us. Touch helps us judge the shape, size, temperature, hardness and other characteristics of objects. This information is essential for our survival and daily activities.

[0003] Virtual reality technology refers to the use of immersive stereoscopic displays, somatosensory feedback devices and other equipment, through a designed human-computer interaction platform, to construct a virtual reality environment that feels similar to the real environment. With the development of virtual reality technology, tactile feedback has become increasingly important in this field. The introduction of tactile feedback enables operators to obtain a better sense of presence and optimizes the operator's operating experience in virtual reality. The tactile feedback device can transmit tactile information in the virtual environment to the operator, further improving the accuracy and sensitivity of the operation. However, most of the current tactile feedback devices are based on pneumatics, dielectric elastomers, piezoelectric materials, etc., which have complex designs, high manufacturing costs, high energy consumption, and limited perception accuracy.

[0004] The information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the invention

[0005] In view of the shortcomings or defects of the above-mentioned prior art, an electromagnetic tactile feedback device and a feedback method are provided, which overcome the defects of the current tactile feedback devices such as slow response, high power consumption and inability to adjust in multiple stages, and have the advantages of fast response speed, simple manufacturing, easy design and adjustment, and ability to achieve multi-mode feedback. The device is suitable for application fields that require a high degree of tactile realism and fine control, such as virtual reality, remote operation and medical simulation.

[0006] The purpose of the present invention is achieved through the following technical solutions.

[0007] An electromagnetic tactile feedback device, comprising: A base, comprising a first flange at the top, a through hole connected to the bottom of the first flange, and a hollow platform connected to the bottom end of the through hole; an electromagnetic coil housed in the hollow table; A tactile needle comprises a hollow receiving portion adapted to enter a through hole and a needle-shaped member extending upward from the hollow receiving portion, wherein a magnet is accommodated in the hollow receiving portion. A plurality of limiting pieces, which are sequentially and spaced apart and penetrate the needle-shaped member; A flexible valve lock, which is transversely fixed in the through hole, comprises a ring and a plurality of flexible teeth extending from the inner wall of the ring to the center, wherein the flexible teeth are bent when acting with the limiting piece, so that after the limiting piece passes over the flexible teeth, the flexible teeth return to their original shape and play a supporting role; An upper cover, comprising a second flange arranged at the bottom and a pipe extending upward from the top of the second flange, wherein the second flange is detachably connected to the first flange; A linear bearing is arranged in the pipe, and the needle-shaped member passes through the linear bearing to limit its movement up and down in the axial position. The electromagnetic coil is energized to generate a magnetic field, and the magnetic field and the magnet act to generate electromagnetic force, so that multiple limit plates act in turn with the flexible valve lock to generate multi-level tactile feedback.

[0008] In the electromagnetic tactile feedback device, the cross section of the through hole is circular, the limiting piece is a limiting circular piece, and the ring piece is a circular ring piece.

[0009] In the electromagnetic tactile feedback device, a magnetic conductive core for enhancing the magnetic field strength is placed in the middle of the electromagnetic coil.

[0010] In the electromagnetic tactile feedback device, the magnet is a circular magnet, and its magnetization direction is axial magnetization perpendicular to the circular cross section.

[0011] In the electromagnetic tactile feedback device, the needle-shaped member and the limiting piece are in an interference fit.

[0012] In the electromagnetic tactile feedback device, a reinforcing rib structure is provided between the hollow accommodating portion and the needle-shaped member.

[0013] In the electromagnetic tactile feedback device, the distances between the plurality of limit plates are equal.

[0014] In the electromagnetic tactile feedback device, the through hole is provided with a groove for placing the flexible valve lock.

[0015] In the electromagnetic tactile feedback device, the multi-level and vibration adjustment of the tactile needle is achieved by adjusting the pulse current size and frequency in the electromagnetic coil.

[0016] The feedback method of the electromagnetic tactile feedback device comprises the following steps: A control circuit is established, wherein the power supply outputs current, the power amplifier module is connected to the power supply to pass the current input by the power supply into the power amplifier module, the power amplifier module is connected to the electromagnetic coil, and the output of the power amplifier module is connected and controlled by the ARM microcontroller. The current is converted into a PWM sampling signal through an ARM microcontroller, and the duty cycle of the PWM signal is changed to control the size of the output current, thereby changing the size of the electromagnetic force generated by the electromagnetic coil, so that multiple limit plates act in turn with the flexible valve lock to produce multi-level tactile feedback. The flexible teeth bend when acting with the limit plates, so that after the limit plates pass over the flexible teeth, the flexible teeth return to their original state and play a supporting role, thereby realizing the switching of the tactile needle between different levels, and adjusting the pulse frequency and positive and negative of the PWM signal so that the output current is high-frequency alternating current, thereby realizing high-frequency vibration of the tactile needle.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention directly controls the electromagnetic force through the magnetic field generated by the electromagnetic coil; structurally, multi-level tactile feedback is achieved through a flexible valve lock; the current output is all pulse current, which does not require continuous output and has low energy consumption; by controlling the duty cycle and frequency of the PWM signal, various modes of the tactile feedback device are achieved; it can be arranged in an array and has scalable application prospects.

[0018] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to achieve the extent that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are illustrated below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0020] In the attached picture: Figure 1 It is a schematic diagram of the explosion structure of the present invention; Figure 2 is a schematic structural diagram of the flexible valve lock of the present invention; Figure 3 It is a cross-sectional schematic diagram of the present invention; FIG4 (a) and FIG4 (b) are schematic diagrams of multi-level feedback control of the present invention, wherein FIG4 (a) is a schematic diagram of multi-level feedback control, and FIG4 (b) is a schematic diagram of the output mode of electromagnetic force during multi-level feedback control; FIG5(a) and FIG5(b) are schematic diagrams of vibration feedback of the present invention, wherein FIG5(a) is a schematic diagram of vibration feedback, and FIG5(b) is a schematic diagram of the output mode of electromagnetic force during vibration feedback regulation; Figure 6 It is a structural schematic diagram of the present invention.

[0021] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0023] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0024] To facilitate understanding of the embodiments of the present invention, several specific embodiments will be further explained below with reference to the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0025] For a better understanding, Figures 1 to 6 As shown, an electromagnetic tactile feedback device includes: A base 9, comprising a first flange at the top, a through hole connected to the bottom of the first flange, and a hollow platform connected to the bottom end of the through hole; an electromagnetic coil 10, which is accommodated in the hollow platform; The tactile needle 3 comprises a hollow receiving portion adapted to enter the through hole and a needle-shaped member extending upward from the hollow receiving portion, wherein the magnet 7 is accommodated in the hollow receiving portion. A plurality of limiting pieces, which are sequentially and spaced apart and penetrate the needle-shaped member; A flexible valve lock 8 is transversely fixed in the through hole, and the flexible valve lock 8 includes a ring and a plurality of flexible teeth extending from the inner wall of the ring to the center. The flexible teeth are bent when acting with the limiting piece, so that after the limiting piece passes over the flexible teeth, the flexible teeth return to their original shape and play a supporting role; An upper cover 2, comprising a second flange arranged at the bottom and a pipe extending upward from the top of the second flange, wherein the second flange is detachably connected to the first flange; A linear bearing 1 is arranged in the pipe fitting, and the needle-shaped member passes through the linear bearing 1 to limit its movement up and down in the axial position. The electromagnetic coil 10 is energized to generate a magnetic field, and the magnetic field and the magnet 7 act to generate an electromagnetic force, so that multiple limit plates act in turn with the flexible valve lock 8 to generate multi-level tactile feedback.

[0026] In a preferred embodiment of the electromagnetic tactile feedback device, the cross section of the through hole is circular, the limiting piece is a limiting circular piece, and the ring member is a circular ring member.

[0027] In a preferred embodiment of the electromagnetic tactile feedback device, a magnetic conductive core is placed in the middle of the electromagnetic coil 10 to enhance the magnetic field strength.

[0028] In a preferred embodiment of the electromagnetic tactile feedback device, the magnet 7 is a circular magnet 7, and its magnetization direction is axial magnetization perpendicular to the circular cross section.

[0029] In a preferred embodiment of the electromagnetic tactile feedback device, the needle-shaped member and the limiting piece are fitted with an interference fit.

[0030] In a preferred embodiment of the electromagnetic tactile feedback device, a reinforcing rib structure is provided between the hollow accommodating portion and the needle-shaped member.

[0031] In a preferred embodiment of the electromagnetic tactile feedback device, the distances between the plurality of limit plates are equal.

[0032] In a preferred embodiment of the electromagnetic tactile feedback device, the through hole is provided with a groove for placing the flexible valve lock 8 .

[0033] In a preferred embodiment of the electromagnetic tactile feedback device, the multi-level and vibration adjustment of the tactile needle 3 is achieved by adjusting the pulse current size and frequency in the electromagnetic coil 10 .

[0034] The feedback method of the electromagnetic tactile feedback device comprises the following steps: A control circuit is established, wherein the power supply outputs current, the power amplifier module is connected to the power supply to pass the current input by the power supply into the power amplifier module, the power amplifier module is connected to the electromagnetic coil 10, and the output of the power amplifier module is connected and controlled by the ARM microcontroller. The current is converted into a PWM sampling signal through an ARM microcontroller, and the duty cycle of the PWM signal is changed to control the size of the output current, thereby changing the size of the electromagnetic force generated by the electromagnetic coil 10, so that multiple limit plates act in turn with the flexible valve lock 8 to generate multi-level tactile feedback. The flexible teeth bend when acting with the limit plates, so that after the limit plates pass over the flexible teeth, the flexible teeth return to their original state and play a supporting role, thereby realizing the switching of the tactile needle 3 between different levels, and adjusting the pulse frequency and positive and negative of the PWM signal so that the output current is high-frequency alternating current, thereby realizing high-frequency vibration of the tactile needle 3.

[0035] In one embodiment, an electromagnetic tactile feedback device includes a base 9, and an electromagnetic coil 10 is placed inside the base 9 as a feedback power source. Based on the electromagnetic principle, the electromagnetic coil 10 is energized so that the circular current generates a magnetic field along the axial direction, and the magnetic field acts on the cylindrical magnet 7. The base 9 also contains a tactile needle 3 inside, and a groove is provided below the tactile needle 3 for placing the cylindrical magnet 7, which is subjected to force and moves, thereby applying tactile stimulation. The tactile needle 3 is sleeved with a three-level limiting disc, and the limiting disc and the flexible valve lock 8 work to produce a multi-level tactile feedback mode. The flexible valve lock 8 is fixed in the groove above the base 9 and contacts the top cover. The top cover and the base 9 are fixed by screws. A linear bearing 1 is installed inside the top cover, and the tactile needle 3 passes through the linear bearing 1 to limit its movement to an axial position.

[0036] Preferably, the electromagnetic tactile feedback device further includes a current control module, which is composed of a power supply and a control circuit. The current output by the power supply is adjusted by an ARM microcontroller and a power amplifier module, and finally transmitted to the electromagnetic coil 10. The control signal generated by the ARM microcontroller is a PWM signal. By adjusting the duty cycle of the PWM sampling signal, the current output to the electromagnetic coil 10 can be changed. At the same time, the PID algorithm is used in the ARM microcontroller to adjust the PWM control signal to achieve precise control of the current in the electromagnetic coil 10.

[0037] Furthermore, by adjusting the pulse frequency of the microcontroller, vibration signals of different frequencies are generated, so that the tactile needle 3 can vibrate at a certain level. Furthermore, the core of the magnetic conductor 7 is made of pure iron with high magnetic permeability. Preferably, the cylindrical magnet 7 is made of N52 permanent magnet 7.

[0038] Preferably, the flexible valve lock 8 is made of PET material by laser cutting, and its inner ring is a multi-tooth structure, which facilitates the switching of the tactile needle 3 between different levels and the vibration at a certain level.

[0039] Preferably, the multi-stage discs are spaced at equal distances from each other, and the distances are designed based on the electromagnetic force and the resistance of the flexible valve lock 8 .

[0040] Preferably, the linear bearing 1 and the top cover are interference fit, that is, fixed inside the upper cover 2, and the inner ring and the tactile needle 3 are transition fit, so that it can move in the axial direction without resistance. All rigid structures are made by 3D printing. Optionally, the above non-standard parts are made by 3D printing PLA material.

[0041] In one embodiment, the feedback method comprises the following steps: Step 1: Build a control circuit, including a power supply, an ARM microcontroller, a power amplifier module, and an electromagnetic tactile interface device with multi-level feedback.

[0042] Step 2: Pass the current input by the power supply into the power amplifier module, and control the output of the power amplifier module through the ARM microcontroller.

[0043] Step 3: The current is converted into a PWM sampling signal through the ARM microcontroller, and the duty cycle of the PWM signal is changed to control the magnitude of the output current, thereby changing the magnitude of the electromagnetic force generated by the electromagnetic coil 10 and realizing the switching of the tactile needle 3 between different levels.

[0044] Step 4: Adjust the pulse frequency and positive and negative of the PWM signal so that the output current is high-frequency alternating current, thereby achieving high-frequency vibration of the tactile needle 3 at a certain level.

[0045] In one embodiment, an electromagnetic tactile feedback device includes an electromagnetic coil 10, and the electromagnetic coil 10 is placed inside a base 9. A through hole is provided inside the base 9 for placing a tactile needle 3, a cylindrical magnet 7 is placed in the groove below the tactile needle 3, and three-level limiting discs 4, 5, and 6 are placed above. The base 9 is fixed to the upper cover 2 by screws, and a flexible valve lock 8 is placed on the connecting part. A linear bearing 1 is embedded in the hole above the upper cover 2, and the tactile needle 3 passes through the inner hole of the linear bearing 1. In the example, the electromagnetic coil contains a magnetic core made of pure iron with high magnetic permeability, which is used to enhance the magnetic field strength and electromagnetic force. The cylindrical magnet adopts N52 permanent magnet and is magnetized along the axial direction to maximize the electromagnetic force.

[0046] Flexible valve lock structure Figure 2As shown, the flexible valve lock material is 0.5mm PET and is cut by laser. There are six teeth inside the flexible valve lock. The tooth structure will bend when it interacts with the limiting disc. After the disc passes over the teeth, it will return to its original shape and play a supporting role. The linear bearing used in the example is the LM-UU series, with an outer diameter of 7mm, an inner diameter of 3mm, and a length of 10mm. The number of turns of the electromagnetic coil in the example is 1000 turns, and the diameter of the copper wire is 0.35mm. The distance between the limiting discs in the example, that is, the distance between different feedback levels is 3mm. This distance can be further designed according to the size of the electromagnetic force and the size of the valve lock resistance.

[0047] In this example, the electromagnetic coil is driven by the L298N driver module. The current output by the power supply is driven by the L298N and adjusted by the ARM microcontroller ARDUINO. The current is adjusted in the form of a PWM wave, that is, the ARM microcontroller ARDUINO controls the duty cycle of the PWM signal to indirectly control the current in the coil, control the direction of the PWM signal and the pulse frequency to generate an AC signal, and control the vibration frequency.

[0048] Figure 3 The cross-sectional diagram of the electromagnetic tactile interface device with multi-level feedback is shown in FIG4 (a). When the electromagnetic coil is energized in the forward direction, an upward electromagnetic force is generated, as shown in FIG4 (a). The generated magnetic field acts on the magnet 7 to make the tactile needle 3 move upward, and stop at this level after passing the flexible valve lock 8. This process is repeated to make the tactile needle continue to move upward, completing the multi-level switching. When the coil is energized in the reverse direction, a downward electromagnetic force is generated, causing the tactile needle to move downward. The energization form is shown in FIG4 (b), that is, a pulse current of a certain length of time can generate a corresponding pulse magnetic field force, thereby completing the switching between different levels.

[0049] Figure 5 (a) is a cross-sectional schematic diagram in vibration mode. When the work done by the applied electromagnetic force does not exceed the resistance work of the flexible valve lock, the applied AC signal can generate vibration force, so that the tactile needle can achieve vibration feedback at any level, and its vibration frequency can also be controlled by changing the pulse frequency of PWM. The schematic diagram of the electromagnetic force generated in one cycle is shown in Figure 5 (b).

[0050] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0051] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. An electromagnetic tactile feedback device, characterized in that: These include, A base, comprising a first flange at the top, a through hole connected to the bottom of the first flange, and a hollow platform connected to the bottom end of the through hole; an electromagnetic coil housed in the hollow table; A tactile needle comprises a hollow receiving portion adapted to enter a through hole and a needle-shaped member extending upward from the hollow receiving portion, wherein a magnet is accommodated in the hollow receiving portion. A plurality of limiting pieces, which are sequentially and spaced apart and penetrate the needle-shaped member; A flexible valve lock, which is transversely fixed in the through hole, comprises a ring and a plurality of flexible teeth extending from the inner wall of the ring to the center, wherein the flexible teeth are bent when acting with the limiting piece, so that after the limiting piece passes over the flexible teeth, the flexible teeth return to their original shape and play a supporting role; An upper cover, comprising a second flange arranged at the bottom and a pipe extending upward from the top of the second flange, wherein the second flange is detachably connected to the first flange; A linear bearing is arranged in the pipe, and the needle-shaped member passes through the linear bearing to limit its movement up and down in the axial position. The electromagnetic coil is energized to generate a magnetic field, and the magnetic field and the magnet act to generate electromagnetic force, so that multiple limit plates act in turn with the flexible valve lock to generate multi-level tactile feedback.

2. The electromagnetic tactile feedback device according to claim 1, characterized in that: Preferably, the cross section of the through hole is circular, the limiting piece is a limiting circular piece, and the ring piece is a circular ring piece.

3. The electromagnetic tactile feedback device according to claim 1, characterized in that: A magnetic conductive core is placed in the middle of the electromagnetic coil to enhance the magnetic field strength.

4. The electromagnetic tactile feedback device according to claim 1, characterized in that: The magnet is a circular magnet, and its magnetization direction is axial magnetization perpendicular to the circular cross section.

5. The electromagnetic tactile feedback device according to claim 1, characterized in that: The cooperation between the needle-shaped piece and the limiting piece is an interference fit.

6. The electromagnetic tactile feedback device according to claim 1, characterized in that: A reinforcing rib structure is provided between the hollow accommodating portion and the needle-shaped member.

7. The electromagnetic tactile feedback device according to claim 1, characterized in that: The distances between the plurality of limiting pieces are equal.

8. The electromagnetic tactile feedback device according to claim 1, characterized in that: The through hole is provided with a groove for placing the flexible valve lock.

9. The electromagnetic tactile feedback device according to claim 1, characterized in that: The multi-level and vibration adjustment of the tactile needle is achieved by adjusting the pulse current size and frequency in the electromagnetic coil.

10. A feedback method for an electromagnetic tactile feedback device according to any one of claims 1 to 9, characterized in that: It includes the following steps: A control circuit is established, wherein the power supply outputs current, the power amplifier module is connected to the power supply to pass the current input by the power supply into the power amplifier module, the power amplifier module is connected to the electromagnetic coil, and the output of the power amplifier module is connected and controlled by the ARM microcontroller. The current is converted into a PWM sampling signal through an ARM microcontroller, and the duty cycle of the PWM signal is changed to control the size of the output current, thereby changing the size of the electromagnetic force generated by the electromagnetic coil, so that multiple limit plates act in turn with the flexible valve lock to produce multi-level tactile feedback. The flexible teeth bend when acting with the limit plates, so that after the limit plates pass over the flexible teeth, the flexible teeth return to their original state and play a supporting role, thereby realizing the switching of the tactile needle between different levels, and adjusting the pulse frequency and positive and negative of the PWM signal so that the output current is high-frequency alternating current, thereby realizing high-frequency vibration of the tactile needle.

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