A rigidity-changing haptic pads with magnetic flux elasticity

Abstract

The present invention relates to a stiffness-changing haptic pad incorporating a magnetorheological elastomer that can freely express the stiffness of various objects in a virtual environment by selectively providing soft contact feedback and hard contact feedback of a rigid body through a structure in which the stiffness changes as it condenses in the direction of a rigid body depending on whether a magnetic field is generated.

Description

Technology Field

[0001] The present invention relates to a stiffness-changing haptic pad to which a magnetorheological elastomer is applied, and more specifically, to a stiffness-changing haptic pad to which a magnetorheological elastomer is applied that can freely express the stiffness of various objects in a virtual environment by selectively providing soft contact feedback and hard contact feedback of a rigid body through a structure in which the stiffness changes as it condenses in the direction of a rigid body depending on whether a magnetic field is generated. Background Technology

[0003] Recently, there has been an increasing number of cases where haptic actuators are installed in portable electronic devices, virtual reality (VR) devices, etc., to provide users with diverse and vivid tactile feedback.

[0004] Haptic actuators are used, for example, to generate vibrations when receiving a call or message on a mobile phone, to generate tactile feedback when selecting a menu through a keypad or touchscreen, or to generate specific tactile feedback during the execution of a game program.

[0005] There is a wide variety of haptic actuators. Generally, eccentric motor actuators (ERM: Eccentric Rotating Mass) using an eccentric vibrator, linear resonant actuators (LRA: Linear Resonant Actuator) that use electromagnetic force to reciprocate a vibrator connected to a spring, and piezoelectric actuators using a piezo element are mainly used. In addition, haptic actuators using electrostatic friction or ultrasonic surface friction, and haptic actuators using electroactive polymers (EAP) are also known.

[0006] Recently, technology that applies vibration modules to haptic actuators linked to game programs is being used to provide a more realistic user experience in game programs. However, technology that applies magnetorheological elastomers (MREs) to the haptic actuators themselves to express various stiffnesses for expressing the stiffness of various objects in a virtual environment is still lacking, and thus, the development of such technology is required. Prior art literature

[0008] Korean Registered Patent No. 10-2129214 The problem to be solved

[0009] The present invention aims to provide a stiffness-changing haptic pad with a magnetorheological elastomer that can freely express the stiffness of various objects in a virtual environment by selectively providing soft contact feedback and hard contact feedback of a rigid body through a structure in which the stiffness changes as it condenses in the direction of a rigid body depending on whether a magnetic field is generated, thereby solving the above-mentioned problems. means of solving the problem

[0011] A stiffness-changing haptic pad to which a magnetorheological elastomer is applied according to one embodiment of the present invention may include a pad-shaped rigid body (110) having one or more through holes (111) formed in a vertical direction, a magnetic field generating module (120) provided at the bottom of the pad-shaped rigid body (110) and generating a magnetic field, and a magnetorheological elastomer structure (130) which is positioned above the pad-shaped rigid body (110) with a portion inserted into the one or more through holes (111) and maintained in a state separated from the pad-shaped rigid body (110), and which changes stiffness as it condenses in a direction toward the pad-shaped rigid body (110) according to the magnetic field generated through the magnetic field generating module (120) and is in close contact with the pad-shaped rigid body (110).

[0012] In one embodiment, a receiving space (112) may be provided inside the pad-shaped rigid body (110) that is connected to the through hole (111) and accommodates a part of the magnetorheological elastic body structure (130).

[0013] In one embodiment, the magnetorheological elastomer structure (130) may include a magnetorheological elastomer plate (131) that maintains a distance from the pad-shaped rigid body (110) above the pad-shaped rigid body (110), and one or more magnetorheological elastomer bridges (132) that protrude in the direction of one or more through holes (111) below the magnetorheological elastomer plate (131).

[0014] In one embodiment, when a magnetic field is generated through the magnetic field generating module (120), the one or more magnetorheological elastomer bridges (132) accommodated in the receiving space (112) are condensed inside the receiving space (112) by magnetic force, and when condensed, the magnetorheological elastomer plate (131) can be moved in close contact toward the pad-shaped rigid body (110).

[0015] In one embodiment, the magnetic field generating module (120) may be any one of a solenoid coil, a unipolar electromagnet, a multipolar electromagnet, a heat dissipation electromagnet for high temperature, a magnetic surface processing electromagnet, a neodymium magnet, a ferrite magnet, an Alnico magnet, a samarium cobalt magnet, and an electric permanent magnet (EPM). Effects of the invention

[0017] According to one aspect of the present invention, through a structure in which stiffness changes as it condenses in the direction of a rigid body depending on whether a magnetic field is generated, it has the advantage of being able to freely express the stiffness of various objects in a virtual environment by selectively providing soft contact feedback and rigid contact feedback. Brief explanation of the drawing

[0019] FIG. 1 is a diagram showing the configuration of a stiffness-changing haptic pad (100) to which a magnetorheological elastomer is applied according to one embodiment of the present invention. FIG. 2 is an exploded view of a stiffness-changing haptic pad (100) to which the magnetorheological elastomer shown in FIG. 1 is applied. FIG. 3 is a drawing showing the pad-shaped rigid body (110) in more detail. FIG. 4 is a drawing showing the magnetorheological elastomer structure (130) in more detail. FIG. 5 is a diagram illustrating the concept in which a magnetorheological elastic structure (130) moves in close contact with a pad-shaped rigid body (110) depending on whether a magnetic field is generated by a magnetic field generating module (120). FIG. 6 is a diagram illustrating the concept that in another embodiment, the rigidity of the magnetorheological elastomer structure (130) changes as it condenses depending on whether the magnetic field of the magnetic field generating module (120) is generated while the pad-type rigid body (110) is excluded. Specific details for implementing the invention

[0020] Preferred embodiments are presented below to aid in understanding the present invention. However, the following embodiments are provided merely to facilitate a better understanding of the invention, and the scope of the invention is not limited by these embodiments.

[0022] FIG. 1 is a diagram showing the configuration of a stiffness-changing haptic pad (100) to which a magnetorheological elastomer is applied according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of the stiffness-changing haptic pad (100) to which a magnetorheological elastomer is applied as shown in FIG. 1.

[0023] Referring to FIGS. 1 and 2, a stiffness-changing haptic pad (100) to which a magnetorheological elastomer according to one embodiment of the present invention is applied is largely composed of a pad-shaped rigid body (110), a magnetic field generating module (120), and a magnetorheological elastomer structure (130).

[0024] The pad-shaped rigid body (110) is a structure for expressing the rigidity of objects in a virtual environment. When the magnetorheological elastomer structure (130), which will be described later, is not in contact, it provides soft contact feedback, but when the magnetorheological elastomer structure (130) condenses and comes into contact, it can provide hard contact feedback. This is described as follows.

[0025] FIG. 3 is a drawing showing the pad-shaped rigid body (110) in more detail.

[0026] Referring to FIG. 3, the pad-shaped rigid body (110) basically has a hollow cuboid shape, and on the upper side, one or more through holes (111) are formed in the vertical direction for inserting a part of the magnetorheological elastic body structure (130) described later. The area and size of the pad-shaped rigid body (110) are not fixed and can be changed as much as needed depending on the type of haptic actuator or object to which they are applied.

[0027] In the inner side of such a pad-shaped rigid body (110), a receiving space (112) is provided that is connected to a plurality of through holes (111) and accommodates a part of a magnetorheological elastomer structure (130). At this time, the part of the magnetorheological elastomer structure (130) accommodated in the receiving space (112) may condense according to the magnetic field of the magnetic field generating module (120) described later, and its shape may be distorted and clumped together, and the clumped part is accommodated within the receiving space (112).

[0029] Next, the magnetic field generating module (120) is provided at the bottom of the pad-shaped rigid body (110) and plays a role in changing the rigidity while condensing the magnetorheological elastic body structure (130) described later by generating a magnetic field.

[0030] The magnetic field generating module (120) may utilize any one of a solenoid coil, a unipolar electromagnet, a multipolar electromagnet, a heat dissipation electromagnet for high temperature, a magnetic surface processing electromagnet, a neodymium magnet, a ferrite magnet, an Alnico magnet, a samarium cobalt magnet, and an electropermanent magnet (EPM), and serves to generate a magnetic field for changing the stiffness of the magnetorheological elastomer structure (130) described later. The magnetic field generating module (120) is largely composed of an electromagnet that generates magnetic force by flowing current through a coil, a permanent magnet that generates magnetic force without an external input power source, and an EPM (Electropermanent Magnet) that maintains a magnetic field when no power is supplied. Examples of electromagnets include a solenoid coil, a unipolar electromagnet, a multipolar electromagnet, a heat dissipation electromagnet for high temperature, and a magnetic surface processing electromagnet.

[0031] The solenoid coil generates a magnetic field when current flows, and when the current flows along the coil, a magnetic field is formed around the coil, and at this time, the magnetic field affects the magnetorheological elastic structure (130).

[0032] A unipolar electromagnet is an electromagnet in which only one pole is generated on one side. While a general electromagnet generates both an N pole and a S pole on one side, a unipolar electromagnet generates only one pole on one side, thereby affecting the change in stiffness of the magnetorheological elastomer structure (130).

[0033] Unlike single-pole electromagnets, multi-pole electromagnets have multiple alternating N and S poles on one side, so they have the characteristic of having excellent adsorption power compared to other electromagnet structures.

[0034] High-temperature heat-dissipating electromagnets are a type of high-temperature electromagnet; unlike conventional electromagnets, which experience reduced adsorption performance in high-temperature environments, high-temperature heat-dissipating electromagnets are characterized by their ability to maintain adsorption performance even in high-temperature conditions.

[0035] A magnetic surface processing electromagnet refers to an electromagnet in which the surface where magnetic force is generated is processed into various shapes, and this can be processed to correspond to the shape of the magnetorheological elastomer structure (130).

[0036] Permanent magnets include neodymium magnets, ferrite magnets, Alnico magnets, and samarium cobalt magnets.

[0037] Neodymium magnets generate the strongest magnetic force relative to their size among currently mass-produced magnets, while ferrite magnets have lower magnetic force but are characterized by their low cost and resistance to heat.

[0038] Alnico magnets possess magnetic force between that of neodymium and ferrite magnets, characterized by high strength and corrosion resistance, and the ability to generate magnetic force stably even at higher temperatures than other magnets. Samarium cobalt magnets combine the advantages of both neodymium and Alnico magnets; although their magnetic force is lower compared to neodymium magnets, they are characterized by the ability to generate a magnetic field stably even at high temperatures and possess high corrosion resistance.

[0039] Unlike the characteristics of a general electromagnet, an electric permanent magnet (EPM) has the characteristic of being able to maintain a magnetic field even when no power is supplied. Therefore, even if the power supply to the magnetic field generating module (120) is cut off, the magnetic force can be maintained.

[0041] Next, the magnetorheological elastomer structure (130) maintains a state of being spaced apart from the pad-shaped rigid body (110) with a portion inserted into one or more through holes (111) on the upper side of the pad-shaped rigid body (110), and plays a role in changing its rigidity and adhering to the pad-shaped rigid body (110) as it condenses in a direction toward the pad-shaped rigid body (110) according to the magnetic field generated through the magnetic field generating module (120) described earlier. This is described as follows.

[0042] FIG. 4 is a drawing showing the magnetorheological elastic body structure (130) in more detail, and FIG. 5 is a drawing showing the concept that the magnetorheological elastic body structure (130) moves in close contact with the pad-shaped rigid body (110) depending on whether the magnetic field of the magnetic field generating module (120) is generated.

[0043] Looking at FIGS. 5 and 6, the magnetorheological elastomer structure (130) has a shape that overlaps with the pad-shaped rigid body (110) on the upper side of the previously described pad-shaped rigid body (110). To this end, the magnetorheological elastomer structure (130) is composed of a flat magnetorheological elastomer plate (131) and one or more magnetorheological elastomer bridges (132).

[0044] The magnetorheological elastomer plate (131) is formed as a flat plate so as to maintain a distance from the pad-type rigid body (110) on the upper side of the pad-type rigid body (110), but when the magnetorheological elastomer bridge (132) is condensed, it comes closer to the pad-type rigid body (110) and comes into close contact.

[0045] The magnetorheological elastomer plate (131) itself is made of a composite of silicone, iron particles, and silicone oil, so it can express softness like rubber, and when a magnetic field is generated through the magnetic field generating module (120), it adheres to the pad-shaped rigid body (110), and thus can express hardness by increasing its rigidity.

[0046] One or more magnetorheological elastomer bridges (132) protrude from the lower side of the magnetorheological elastomer plate (131) and are inserted and received into the receiving space (112) through the through hole (111) of the pad-shaped rigid body (110).

[0047] At this time, the magnetorheological elastomer plate (131) is maintained at a certain distance from the pad-shaped rigid body (110) due to the initial length of the magnetorheological elastomer bridge (132), and when a magnetic field is generated through the magnetic field generation module (120), the magnetorheological elastomer bridge (132) condenses and its shape becomes compressed as shown in Fig. 5, and accordingly, as the height of the magnetorheological elastomer plate (131) itself decreases, the magnetorheological elastomer plate (131) can be in close contact with the upper surface of the pad-shaped rigid body (110).

[0048] In particular, when a magnetic field is generated, the iron powder inside the magnetorheological elastomer structure (130) aligns according to the magnetic flux and becomes hard due to the attractive force between the iron particles, thereby increasing the rigidity. In this state, when a user touches, taps, or strikes the magnetorheological elastomer plate (131) with a stick or palm, they can feel a hard and solid contact feedback.

[0050] Meanwhile, in a stiffness-changing haptic pad (100) to which a magnetorheological elastomer is applied according to one embodiment of the present invention, various stiffnesses can be expressed using only the magnetorheological elastomer structure (130) without the pad-shaped rigid body (110), and this is described as follows.

[0051] FIG. 6 is a diagram illustrating the concept that in another embodiment, the rigidity of the magnetorheological elastomer structure (130) changes as it condenses depending on whether the magnetic field of the magnetic field generating module (120) is generated while the pad-type rigid body (110) is excluded.

[0052] Referring to FIG. 6, in another embodiment of the present invention, excluding the pad-type rigid body (110), the magnetorheological elastic structure (130) is seated on the upper side of the magnetic field generating module (120), and a change in the stiffness of the magnetorheological elastic structure (130) can be induced through the generation of a magnetic field by the magnetic field generating module (120).

[0053] Before the magnetic field is generated, the magnetorheological elastomer structure (130) itself can provide very soft and smooth contact feedback, and when the magnetic field is generated, the magnetorheological elastomer bridge (132) condenses, and the height of the magnetorheological elastomer plate (131) itself is partially lowered, but the rigidity is increased.

[0054] At this time, unlike when the pad-shaped rigid body (110) was present earlier, contact feedback can be provided with a rigidity between rubber and clay, rather than a hard or firm feeling. Additionally, when the magnetic field generation is released, the magnetorheological elastomer bridge (132) returns to its original shape, and the magnetorheological elastomer plate (131) rises again.

[0056] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0058] 100: Stiffness-changing haptic pad with magnetorheological elastomer 110: Pad-type rigid body 111: Through hole 112: Accommodation space 120: Magnetic field generation module 130: Magnetorheological elastomer structure 131: Magnetorheological elastomer plate 132: Magnetorheological elastomer bridge

Claims

Claim 1 A pad-shaped rigid body (110) having a plurality of through holes (111) formed in a vertical direction and a receiving space (112) connected to the plurality of through holes (111) on the inner side thereof; wherein the lower side of the receiving space (112) is open to the outside and a magnetic field generating module (120) is provided at the bottom of the pad-shaped rigid body (110) and generates a magnetic field; and a magnetorheological elastic body structure (130) located on the upper side of the pad-shaped rigid body (110), wherein the magnetorheological elastic body structure (130) comprises a magnetorheological elastic body plate (131) that maintains a distance from the pad-shaped rigid body (110) on the upper side of the pad-shaped rigid body (110). and a plurality of magnetorheological elastomer bridges (132) that protrude in the direction of the plurality of through holes (111) from the lower side of the magnetorheological elastomer plate (131) and contact the magnetic field generating module (120); wherein the magnetorheological elastomer plate (131) maintains a state separated from the pad-type rigid body (110) with the plurality of magnetorheological elastomer bridges (132) inserted into the plurality of through holes (111); and when a magnetic field is generated through the magnetic field generating module (120), the plurality of magnetorheological elastomer bridges (132) contained in the receiving space (112) condense inside the receiving space (112) by magnetic force, and upon condensation, the magnetorheological elastomer plate (131) moves toward the pad-type rigid body (110), and as a result, the magnetorheological elastomer plate (131) and one side of the pad-type rigid body (110) A stiffness-changing haptic pad with a magnetorheological elastomer applied, characterized by being configured to be in close contact. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A stiffness-changing haptic pad with a magnetorheological elastomer, wherein the magnetic field generating module (120) is characterized by having one of a solenoid coil, a unipolar electromagnet, a multipolar electromagnet, a high-temperature heat dissipation electromagnet, a magnetic surface processing electromagnet, a neodymium magnet, a ferrite magnet, an Alnico magnet, a samarium cobalt magnet, and an electric permanent magnet (EPM). Claim 6 A stiffness-changing haptic pad with a magnetorheological elastomer applied thereto, characterized in that, in claim 1, the plurality of magnetorheological elastomer bridges (132) are spaced apart from each other at a certain distance. Claim 7 A stiffness-changing haptic pad to which a magnetorheological elastomer is applied, wherein, in claim 1, the plurality of magnetorheological elastomer bridges (132) are each cylindrical in shape. Claim 8 A stiffness-changing haptic pad with a magnetorheological elastomer applied thereto, characterized in that, in claim 1, when a magnetic field is generated through the magnetic field generating module (120) and the plurality of magnetorheological elastomer bridges (132) are condensed, the condensed plurality of magnetorheological elastomer bridges (132) fill the empty space inside the receiving space (112). Claim 9 delete Claim 10 A rigidity-changing haptic pad with a magnetorheological elastomer applied thereto, characterized in that, in claim 1, the pad-shaped rigid body (110) is formed with an area corresponding to the upper area of ​​the magnetic field generating module (120).

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