A virtual reality-based haptic enhancement training system

Abstract

This invention relates to a virtual reality-based haptic enhancement training system, comprising a virtual reality unit, a haptic feedback unit, and a processing unit. The virtual reality unit interacts with the virtual reality environment; the haptic feedback unit is worn on the hand and applies traction force to the fingers, providing feedback on the force corresponding to a grasping object in the virtual reality environment. The processing unit determines the contact points of the grasping object in the virtual reality environment, analyzes the force applied by the haptic feedback unit to the fingers based on these contact points, and sends force-related information to the haptic feedback unit. The force is correlated with the physical characteristics of each contact point of the grasping object. This invention achieves a more realistic force feedback effect by applying traction force to the fingers when the user interacts with virtual objects, allowing the user to experience realistic physical feedback during interaction and enhancing the user's immersion in the interaction.

Description

Technical Field

[0001] This invention relates to the field of rehabilitation training technology, and in particular to a tactile enhancement training system based on virtual reality. Background Technology

[0002] With the rapid development of digital virtual technologies such as Virtual Reality (VR) and Augmented Reality (AR), human-computer interaction methods need continuous upgrading to adapt to more complex and diverse application scenarios. Currently, existing virtual reality rehabilitation training mainly relies on ordinary VR glasses and controllers. Users perform actions such as clicking, moving, and dragging hand models in virtual scenes, all controlled by VR controllers. However, due to technological limitations, this method has significant shortcomings in tactile feedback. In the current virtual training environment, the crucial tactile transmission link is often ignored when hand patients make decisions and perform operations. When users grasp and manipulate virtual objects, the tactile feedback of the hand is not realistic enough, resulting in inaccurate force feedback and muscle memory during training. This unnatural tactile feedback not only fails to help users acquire correct muscle memory but also seriously affects the improvement of training effectiveness. Therefore, providing a virtual reality-based tactile enhancement training system is extremely necessary.

[0003] The applications of haptic enhancement training are very broad. In rehabilitation training, this technology can help patients with impaired hand function gradually regain their motor abilities. Patients can undergo rehabilitation training in a safe and controlled environment, enhancing muscle strength and coordination. In surgical training, haptic feedback can provide a realistic hand manipulation experience in virtual surgical simulations. Doctors can feel the real tactile sensation between surgical instruments and tissues in a simulated environment, thereby improving their surgical skills and decision-making abilities. Furthermore, for many professions requiring delicate hand manipulation (such as beauticians and technicians), haptic enhancement training can also provide a simulated training environment, helping trainees master the necessary hand skills without risk. In the gaming and entertainment field, haptic feedback can enhance the user's immersive experience, improve game interactivity, and allow players to receive realistic haptic feedback in a virtual environment, increasing the fun and challenge of the game. In education and scientific research, haptic enhancement training can be used for simulated experiments and scientific operations, allowing students to practice actual operations in a virtual environment, thereby deepening their understanding and memory.

[0004] To achieve effective tactile enhancement training, certain specific training needs must be met. First, tactile enhancement training equipment must provide high-precision tactile feedback to ensure users experience realistic force feedback and tactile sensations during operation, which is crucial for muscle memory formation. Second, the equipment should offer personalized training programs, adjusting training content and difficulty settings to suit different users' needs, making it challenging yet not overly difficult. Furthermore, real-time monitoring of user operations and performance during training, along with immediate feedback, helps users correct errors promptly, thereby improving training effectiveness. Additionally, the equipment's user interface should be simple and easy to understand, facilitating use by users with various backgrounds, especially patients requiring rehabilitation training. Finally, user safety must be fully considered when designing a tactile enhancement training system to avoid physical fatigue or other injuries caused by misoperation or overuse. In conclusion, tactile enhancement training not only enhances the effectiveness of virtual reality rehabilitation training but can also be applied in multiple fields to meet the training needs of diverse users. Therefore, developing virtual reality-based tactile enhancement training systems will provide important support for achieving more realistic and effective training and rehabilitation.

[0005] For example, patent document CN112400151A discloses a method for providing haptic responses to a haptic feedback device, comprising: receiving physical motion input by an application providing a virtual environment executed on a computer device, at least based on the movement of the haptic feedback device, the movement of the haptic feedback device corresponding to virtual motion interaction with a virtual object in the virtual environment; accessing a haptic signature associated with the virtual object; determining a haptic response at least based on the haptic signature to identify the virtual object by the haptic response; and transmitting the haptic response to the haptic feedback device. The haptic feedback provided by this technical solution has poor realism and still cannot allow users to experience truly realistic tactile sensations in a virtual reality environment.

[0006] For example, patent document CN117582643A discloses a method and system for comprehensive audiovisual training based on virtual reality. The method includes: analyzing scene feedback data from simulated motion tasks to obtain visual feedback datasets and auditory feedback datasets; real-time acquisition of hand movement data from a target user, generating simulated animation data from a target hand model; filtering the visual and auditory feedback datasets to obtain target visual feedback data and target auditory feedback data; displaying the target visual and auditory feedback data to the target user through a virtual reality display terminal; analyzing hand pressure data for pressure density to obtain pressure density data; and using training gloves to assist in training control based on the pressure density data. This technical solution primarily relies on audiovisual feedback for training, but the training gloves lack sufficient flexibility, resulting in poor hand training effectiveness for the user.

[0007] How to provide users with more realistic haptic feedback and improve the effectiveness of virtual reality-based haptic enhancement training is a problem that has not yet been solved.

[0008] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0009] Currently, due to technological limitations, the VR peripherals used in existing virtual reality rehabilitation training are all ordinary VR glasses and controllers. Clicking, moving, and dragging actions of the hand model in the virtual scene are all performed by the user controlling the VR controller. The hand is a crucial area for decision-making by patients and needs effective and accurate force feedback and muscle memory. At present, the grasping operation of the virtual hand model is achieved by the user gripping the VR controller and pressing relevant buttons on the controller. However, the tactile feedback from the user's hand in reality is unnatural, making this tactile feedback incorrect. This not only fails to obtain correct muscle memory but also significantly reduces the training effect.

[0010] To address the shortcomings of existing technologies, this invention provides a virtual reality-based haptic enhancement training system, comprising a virtual reality unit, a haptic feedback unit, and a processing unit. The virtual reality unit interacts with the virtual reality environment; the haptic feedback unit, worn on the hand, applies traction force to the fingers, providing feedback on the force corresponding to a grasping object in the virtual reality environment; the processing unit determines the contact points of the grasping object in the virtual reality environment, analyzes the force fed back by the haptic feedback unit to the fingers based on the contact points, and sends force-related information to the haptic feedback unit, wherein the force is correlated with the physical characteristics of each contact point of the grasping object.

[0011] This invention achieves a more realistic force feedback effect by applying traction force to the fingers when the user interacts with virtual objects, allowing the user to feel real physical feedback during the interaction and enhancing the user's sense of immersion.

[0012] According to a preferred embodiment, the virtual reality-based haptic enhancement training system further includes an EEG signal acquisition unit communicatively connected to the processing unit. The EEG signal acquisition unit acquires real-time cognitive load neural information from the head, and the processing unit adjusts the feedback intensity of the force based on this cognitive load neural information. This configuration allows users to adapt to tasks of varying difficulty.

[0013] According to a preferred embodiment, the haptic feedback unit includes a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The control mechanism is communicatively connected to the drive mechanism, the traction mechanism, and the haptic feedback mechanism. The control mechanism constructs drive commands and haptic feedback commands based on information related to the force applied. The drive mechanism and the traction mechanism are connected and adjust the traction direction and / or traction intensity of the traction mechanism located at the fingertips based on the drive commands to push the finger joints to bend or extend. The haptic feedback mechanism is located at the fingertips and / or knuckles. The haptic feedback mechanism applies physical stimulation to the hand based on the haptic feedback commands to provide corresponding tactile feedback. The traction mechanism and the haptic feedback mechanism are linked together, allowing the user to perceive the physical characteristics of the grasped object based on the flexing motion of the hand formed by the traction. This arrangement facilitates a natural haptic feedback experience for the hand.

[0014] According to a preferred embodiment, when a user adjusts their hand movements based on haptic feedback, the virtual reality unit updates the virtual reality environment based on the hand movements and sends updated force-related information to the processing unit. Real-time updates help ensure that the hand movements in the virtual reality environment remain consistent with real-world hand movements.

[0015] According to a preferred embodiment, the haptic feedback mechanism in the haptic feedback unit includes an inertial sensor and a motion tracking module. The inertial sensor is located at the finger joints to collect information on finger bending movements, while the motion tracking module is located in the wrist housing to collect information on hand movement. The virtual reality unit adjusts the hand model in the virtual reality environment based on the finger bending and hand movement information, thus creating realistic hand movements within the virtual reality environment. This configuration ensures that the user's actual movements are consistent with the hand movements in the virtual reality environment, and allows the user to experience relatively realistic force feedback from the grasped object in real time, enabling the user to feel realistic tactile sensations even in the virtual reality environment.

[0016] According to a preferred embodiment, the haptic feedback unit is mounted on the glove frame in a wearable form, comprising a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The control mechanism is located on the back of the hand within the glove frame; the drive mechanism is located near the metacarpophalangeal joints on the back of the hand; and the traction mechanism connects the drive mechanism to the haptic feedback mechanism worn on the fingertips via traction lines. The traction mechanism adaptively bends and stretches based on finger flexion movements. Inertial sensors are positioned at locations corresponding to the finger joints within the traction mechanism to collect the relative distance and pressure values ​​of each finger joint. The processing unit detects hand movements in real time based on the relative distance and pressure values ​​of each finger joint. This configuration facilitates more realistic determination of hand movements and postures and provides more realistic haptic feedback to the hand.

[0017] According to a preferred embodiment, the haptic feedback mechanism in the haptic feedback unit provides haptic feedback by applying vibration and / or pressure to the fingertips. This configuration allows the user to feel the force or vibration corresponding to the physical characteristics of the object being grasped, resulting in a more realistic experience.

[0018] According to a preferred embodiment, the drive mechanism and the traction mechanism are connected by a pulley mechanism. The drive mechanism changes the magnitude and direction of the force of each traction line in the traction mechanism by adjusting the pulley mechanism, which is beneficial for more flexible adjustment of the bending movement of the fingers.

[0019] According to a preferred embodiment, the traction mechanism has an optical fiber sensor located at the fingertip; the tactile feedback mechanism is a tactile electrode membrane worn on the fingertip, which applies physical stimulation to the hand to provide corresponding tactile feedback. The tactile electrode membrane is easy to attach to the finger and convenient to use.

[0020] According to a preferred embodiment, the haptic feedback unit, in a wearable form, incorporates a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism on a glove frame. The glove frame includes a back-side outer shell frame, a joint frame, a middle back-side outer shell frame, a wrist shell, a palm frame, and a soft padding portion in the palm. The glove frames are interconnected to accommodate palm movements. An embedded frame drive mechanism adjusts the connection angles of the connectors between the back-side outer shell frame, the joint frame, the middle back-side outer shell frame, and the palm frame based on commands from the frame control mechanism. This allows the glove frame to pull the palm and apply force feedback to it. This glove frame configuration allows for flexible movement of the palm and finger joints, reducing mechanical resistance to finger movements. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the connection relationships of the virtual reality-based haptic enhancement training system provided by the present invention;

[0022] Figure 2 This is a logical schematic diagram of the virtual reality-based haptic enhancement training system provided by the present invention;

[0023] Figure 3 This is a schematic diagram illustrating the operating principle of the virtual reality-based haptic enhancement training system provided by the present invention.

[0024] Figure 4 This is a first test schematic diagram of the haptic enhancement training system based on virtual reality provided by the present invention;

[0025] Figure 5 This is a second test schematic diagram of the haptic enhancement training system based on virtual reality provided by the present invention;

[0026] Figure 6This is a schematic diagram of the back of the hand structure of the tactile feedback unit provided by the present invention in the wearing state;

[0027] Figure 7 This is a schematic diagram of the back of hand structure of the tactile feedback unit provided by the present invention;

[0028] Figure 8 This is a schematic diagram of the palm structure of the haptic feedback unit provided by the present invention in the wearing state;

[0029] Figure 9 This is a schematic diagram of the palm structure of the tactile feedback unit provided by the present invention;

[0030] Figure 10 This is an exploded view of the structure of the tactile feedback unit provided by the present invention.

[0031] List of reference numerals

[0032] 100: Virtual Reality Unit; 200: Processing Unit; 300: EEG Signal Acquisition Unit; 400: Tactile Feedback Unit; 401: Back of Hand Shell Skeleton; 402: Joint Skeleton; 403: Tactile Electrode Membrane; 404: Fiber Optic Sensor; 405: Traction Cable; 406: Microcontroller; 407: Power Management Module; 408: Back of Hand Middle Shell Skeleton; 409: Wrist Shell; 410: Palm Skeleton; 411: Palm Soft Filling. Detailed Implementation

[0033] The following is a detailed explanation with reference to the accompanying drawings.

[0034] Currently, due to technological limitations, the VR peripherals used in existing virtual reality rehabilitation training are all ordinary VR glasses and controllers. Clicking, moving, and dragging actions of the hand model in the virtual scene are all performed by the user controlling the VR controller. The hand is a crucial area for decision-making by patients and needs effective and accurate force feedback and muscle memory. At present, the grasping operation of the virtual hand model is achieved by the user gripping the VR controller and pressing relevant buttons on the controller. However, the tactile feedback from the user's hand in reality is unnatural, making this tactile feedback incorrect. This not only fails to obtain correct muscle memory but also significantly reduces the training effect.

[0035] like Figures 1 to 2As shown, the virtual reality-based haptic enhancement training system of the present invention includes a virtual reality unit 100, a haptic feedback unit 400, and a processing unit 200. The virtual reality unit 100 is used to interact with the virtual reality environment. The haptic feedback unit 400 is worn on the hand and provides feedback to the fingers by applying traction force to the fingers, corresponding to the force of a grasping object in the virtual reality environment, thus realizing haptic feedback and hand interaction. The processing unit 200 is used to determine the contact points of the grasping object in the virtual reality environment, analyze the force of the haptic feedback unit 400 on the fingers based on the contact points of the grasping object, and send information related to the force to the haptic feedback unit 400, wherein the force is associated with the physical characteristics of each contact point of the grasping object.

[0036] According to a preferred embodiment, such as Figures 1 to 2 As shown, the system also includes an EEG signal acquisition unit 300 communicatively connected to the processing unit 200. The EEG signal acquisition unit 300 acquires EEG signals from the head in real time. The processing unit 200 adjusts the intensity of the tactile feedback based on the EEG signals. For example, the EEG signal acquisition unit 300 is an EEG cap. During training, the processing unit 200 optimizes the tactile force feedback method based on the EEG signals sent by the EEG signal acquisition unit 300. For example, when the accuracy of grasping objects is detected to be low in a virtual reality environment, the processing unit 200 will increase the degree of tactile feedback.

[0037] like Figure 1 As shown, the EEG signal acquisition unit 300 sends EEG signals to the physiological signal data acquisition device g.USBamp in the VR device. The physiological signal data acquisition device g.USBamp sends the user's motor imagery information to the processing unit 200, which processes the data and simulates the scene in the virtual reality environment. After data processing, the processing unit 200 also generates the user's cognitive assessment information, namely the user's cognitive ability and state information. The physiological signal data acquisition device g.USBamp analyzes and assesses cognitive load from the EEG signals.

[0038] The EEG signal acquisition unit 300 collects EEG signals from electrodes on the user's scalp and sends them to the haptic feedback unit 400. The haptic feedback unit 400 decodes brain activity to trigger corresponding haptic feedback or actions, achieving behavior mapping. The haptic feedback unit 400 performs hand interaction in a virtual reality environment. In the virtual reality environment, the haptic feedback unit 400 applies haptic feedback to the hand, and the hand transmits the haptic feedback information to the brain via nerves.

[0039] Through the interaction of VR devices, processing unit 200, EEG signal acquisition unit 300 and haptic feedback unit 400 in a virtual reality environment, users can achieve multimodal interaction in the virtual reality environment. For example, they can interact in the virtual scene through eye tracking and language control, and apply sensory stimulation to the user through the virtual reality environment and haptic feedback unit 400, such as forming visual feedback and auditory feedback.

[0040] According to a preferred embodiment, when a user adjusts their hand movements based on tactile feedback information, the virtual reality unit 100 updates the virtual reality environment based on the hand movements and sends updated force-related information to the processing unit 200.

[0041] like Figure 3 As shown, the operating principle of this invention is as follows:

[0042] When the hand is not in contact with a virtual object in the virtual reality environment, the drive mechanism, such as a motor, is not activated, and the processing unit 200 does not send haptic feedback-related information to the haptic feedback unit 400. When the hand just begins to contact the virtual object, the processing unit 200 sends haptic feedback-related information to the haptic feedback unit 400, which then begins to apply traction force to the fingers based on changes in contact. At this time, the motor drives multiple traction lines 405 (e.g., ropes) to begin moving. When the hand fully grasps the virtual object, the haptic feedback unit 400 applies force to the corresponding fingers based on the contact point between the palm and the virtual object. At this time, the traction lines 405 (e.g., ropes) are limited, preventing the hand's grasping range from exceeding the object's volume, thus allowing the hand to fully grasp the object and generating the haptic sensation of contact with the virtual object.

[0043] like Figure 4 As shown, the user performs a simple first test of throwing objects in a virtual reality environment. Figure 4 In the game, after starting, step 1: grasp the object and move it into the air; step 2: throw the object; end.

[0044] like Figure 5 As shown, the user performs a second archery test in a virtual reality environment. Figure 5 The process begins with the action of holding the bow. Step 1: Nocking the arrow; Step 2: Drawing the bow; Step 3: Releasing the arrow. The ending state is when the arrow hits the target or falls to the ground. Throughout this process, the user experiences force feedback during the continuous processes of nocking, drawing the bow, and releasing the arrow through the haptic feedback unit 400, that is, the tactile sensation of drawing the bow, the tactile sensation of nocking the arrow, and the tactile sensation of no force after releasing the arrow.

[0045] Figures 6 to 10 One type of mechanical mechanism of the haptic feedback unit 400 is shown.

[0046] like Figure 2 , Figures 6 to 10 As shown, the haptic feedback unit 400 includes a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The control mechanism is communicatively connected to the drive mechanism, the traction mechanism, and the haptic feedback mechanism. The control mechanism constructs drive commands and haptic feedback commands based on force-related information. The drive mechanism and the traction mechanism are connected and adjust the traction direction and / or traction intensity of the traction mechanism located at the finger area based on the drive commands to push the hand joints to bend or extend. The drive mechanism, for example, is a motor, responsible for adjusting the tension of the traction cable 405 to simulate different forces and sensations. The control mechanism generates corresponding force feedback commands based on the interactive context in the virtual reality environment and adjusts the tension of the traction cable 405 via the motor to transmit force feedback to the user's fingers.

[0047] The haptic feedback mechanism is located at the fingertips and / or knuckles. Based on haptic feedback commands, the mechanism applies physical stimulation to the hand to provide corresponding tactile feedback. The traction mechanism and the haptic feedback mechanism work together to allow the user to perceive the physical characteristics of the object being grasped based on the flexing motion of the hand caused by traction. The haptic feedback mechanism in the haptic feedback unit 400 provides haptic feedback by applying vibration and / or pressure to the fingertips.

[0048] This invention, through the mechanical mechanism of the traction line 405, can achieve more detailed and precise force feedback, simulate diverse tactile sensations, and provide users with a more realistic virtual experience through a simple and efficient force feedback transmission method.

[0049] like Figure 2 , Figures 6 to 10 As shown, the haptic feedback mechanism in the haptic feedback unit 400 includes an inertial sensor and a motion tracking module. The motion tracking module, for example, is a three-dimensional coordinate sensor used to acquire the three-dimensional coordinate position of the hand's point of force. This allows for the positioning of the manipulated object within the virtual environment after 3D modeling.

[0050] An inertial sensor is located at the finger joint to collect information on finger bending movements, and a motion tracking module is located in the wrist housing 409 to collect information on hand movement.

[0051] The virtual reality unit 100 adjusts the hand model in the virtual reality environment based on the bending motion information of the fingers and the movement motion information of the hand, so as to form realistic hand movements in the virtual reality environment.

[0052] like Figures 6 to 10As shown, the haptic feedback unit 400 is mounted on the glove frame in a wearable form, incorporating a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The control mechanism is located on the back of the hand within the glove frame, the drive mechanism is located near the metacarpophalangeal joints on the back of the hand, and the traction mechanism connects the drive mechanism to the haptic feedback mechanism worn on the fingertips via traction wires 405. The traction mechanism adaptively bends and stretches based on finger flexion movements. Inertial sensors are positioned at locations corresponding to the finger joints of the traction mechanism to collect the relative distance and pressure values ​​of each finger joint. The processing unit 200 detects hand movements in real time based on the relative distance and pressure values ​​of each finger joint.

[0053] Specifically, each sensor on the haptic feedback unit 400 (including the sensor at the fingertip) has a three-dimensional coordinate (x, y, z) representing its position in the virtual reality environment. The relative distance value is the relative distance between fingers or between a finger and a virtual object. The pressure value represents the intensity of pressure felt when the finger contacts a virtual object.

[0054] The process by which the processing unit 200 calculates the relative distance and pressure values ​​of each finger joint of the hand is shown below.

[0055] S101: First, define a basic hand posture (such as a relaxed state) and set the initial three-dimensional coordinates of each sensor on each finger. The sensors may include a pressure sensor, a distance sensor, a haptic feedback element located within the haptic electrode membrane 403, and a fiber optic sensor 404.

[0056] S102: Update 3D coordinates. Based on real-time data from each sensor, update the 3D coordinates of the sensors for each finger.

[0057] S103: Calculate the relative distance.

[0058] The process of calculating the distance between fingers is shown below.

[0059] For each pair of fingers (e.g., thumb and index finger), calculate the Euclidean distance between them.

[0060] d ij＝ (x i -x j ) 2 +(y i -y j ) 2 +(z i -z j ) 2 .

[0061] i and j are the indices of the fingers.

[0062] The process of calculating the distance between the finger and the object is shown below.

[0063] If there are interactive objects in the virtual reality environment, calculate the distance between the finger and the nearest point of that object.

[0064] S104: Adjust posture according to pressure value.

[0065] As the pressure increases, assuming the finger is bending in a certain direction or making closer contact, the three-dimensional coordinates of the finger can be adjusted proportionally according to the pressure value to make it closer to the target point (such as a virtual object).

[0066] Set a pressure threshold; when the pressure exceeds the pressure threshold, it is considered that the finger has fully contacted and "grabbed" the object.

[0067] S105: Attitude synthesis.

[0068] By combining the 3D coordinates and relative positions of sensors on all fingers, the pose of the entire hand is synthesized. This may require some interpolation and smoothing to ensure the continuity and naturalness of the pose.

[0069] like Figures 6 to 10 As shown, the drive mechanism and the traction mechanism are connected via a pulley mechanism. The pulley mechanism is connected to the microcontroller 406. The drive mechanism adjusts the pulley mechanism to change the magnitude and direction of the force on each traction line 405 in the traction mechanism. The pulley mechanism guides the movement path of the traction lines 405. The pulley mechanism is partially embedded in the joint frame 402, thus connecting to the joint frame 402. The pulley mechanism is designed to be compact, ensuring minimal friction during finger movement.

[0070] like Figures 6 to 10 As shown, a fiber optic sensor 404 is installed at the fingertip of the traction mechanism. The tactile feedback mechanism is a tactile electrode membrane 403 worn on the fingertip. The tactile electrode membrane 403 applies physical stimulation to the hand to provide corresponding tactile feedback. The tactile electrode membrane 403 has perforations at both the nail direction and the fingertip, forming a hole. Preferably, the perforations not only reduce the weight of the tactile electrode membrane 403, achieving lightweighting, but also serve as a location for adding hot / cold tactile or microwave vibration modules, further increasing the dimensions of tactile feedback for the user and allowing the user to receive more types of tactile feedback.

[0071] Preferably, the tactile electrode film 403 is provided with tactile feedback elements such as a constrictor and a heating device. Preferably, the tactile feedback elements apply physical signals to the fingertips exposed by the cutouts, so that the user can feel the touch through the fingertips. When these tactile feedback elements receive control signals, they generate tactile feedback of different intensities and modes, such as vibration and pressure.

[0072] like Figures 6 to 10 As shown, the haptic feedback unit 400 is mounted on the glove frame in a wearable form, incorporating a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The glove frame includes a back-side outer shell frame 401, a joint frame 402, a middle back-side outer shell frame 408, a wrist outer shell 409, a palm frame 410, and a soft padding portion 411. The glove frames are interconnected to accommodate palm movements.

[0073] Specifically, a microcontroller 406 is rotatably mounted on the joint skeleton 402. The microcontroller 406 is connected to a drive mechanism. Preferably, the drive mechanism is a ring motor. The drive mechanism is connected to a traction cable 405. An inertial sensor is provided at the corresponding position on the traction cable 405 corresponding to the finger joint. Specifically, an inertial sensor and a pressure sensor are respectively provided at both ends of the linkage on the traction cable 405 at the two joints of the finger. The inertial sensor and the pressure sensor are respectively connected to the microcontroller 406 via Bluetooth signal. Preferably, Bluetooth signal here is one example of wireless communication method and does not represent the only wireless communication method.

[0074] Existing technology uses a traction line attached to the glove to guide finger bending and movement. The disadvantages of this approach are: (1) The traction line, lacking structural variation, typically applies force only in a single direction and cannot be flexibly adjusted according to the bending requirements of different finger joints. This leads to uneven force transmission during finger bending, making precise control of the bending angle difficult. (2) The traction line may cause uneven force distribution during finger bending, with some parts bearing excessive pressure while others receive insufficient force, affecting the overall coordinated movement of the finger. (3) The traction line typically applies force at a fixed point on the finger, failing to dynamically adapt to the movement needs of different parts of the finger. This fixed force application method may cause some finger joints to bear excessive force, while other joints cannot achieve the required bending range.

[0075] Preferably, the end of the traction wire 405 is connected to the tactile electrode film 403. The traction wire 405 is made by 3D printing. The traction wire 405 is printed into a geometric shape by a 3D printing device, which can precisely control the direction and angle of the feedback force, and has more variation and inertia than the linear contraction mode of a single traction wire. The material of the traction wire 405 has good ductility. Ductility refers to the ability of a material to undergo plastic deformation without breaking under the action of external force. The traction wire 405 can change shape without breaking immediately when stretched or compressed. The traction wire 405 of the present invention includes a knuckle segment and a finger segment disposed on the back surface of the finger. The traction wire 405 is disposed on the back of the finger, so that the side and palm side of the finger are exposed and not constrained by any material. The reason for this arrangement is: (1) to reduce interference with finger movement; by placing the traction wire 405 on the back of the finger, the side and palm side of the finger are avoided, thereby ensuring that the finger is not restricted when performing complex movements and grasping operations. (2) Enhance finger sensitivity; the palm and side surfaces are the most sensitive parts of the fingers, especially the palm side used for touch and sensation. Exposing these areas preserves the tactile sensitivity of the fingers, ensuring that the user can accurately perceive and control finger movements. (3) The traction line 405 on the back can evenly distribute and transmit the applied force when the finger is bent, reducing the problem of excessive local pressure and preventing unnecessary injury or discomfort. At the same time, the back of the finger is an area with less force when naturally bent, and the traction line 405 placed here can conform to the natural force line of the finger, reducing pressure and friction on the joints of the finger.

[0076] The traction line 405 in the finger joint segment is connected via a linkage mechanism, with minimal coverage on the back of the finger. This linkage connection effectively distributes the force applied to the joint, reducing localized pressure and preventing discomfort and injury. The linkage design, arranged along the back of the finger, conforms to the natural force line of the finger, optimizing the force transmission path.

[0077] The traction wire 405 of the finger segment is pre-printed into a geometrically shaped connector and has extensibility. For example... Figures 6 to 10As shown, preferably, the traction line 405 of the finger segment is pre-printed in a hexagonal shape. The traction line 405 of the finger segment can be a standard regular hexagon or a symmetrical hexagon with a certain length. The traction line 405 of the finger segment can also be a quadrilateral, octagon, trapezoid, or other geometric shape. Preferably, the traction line 405 of the finger segment can also be an irregular geometric shape or irregular structure. Except for the thumb, the other four fingers of the hand each have two finger segments. One end of the geometric traction line 405 is rotatably connected to a connecting rod. Thus, the geometric traction lines 405 of the two finger segments are rotatably connected by a connecting rod, and the connecting rod is connected to the end of the geometric traction line 405. The width of the geometric traction line 405 is close to the width of the finger. For example, the shape of the hexagonal traction line 405 is set along the contour of the knuckle, its longer side is close to the long side contour of the finger, and the protruding end is connected to the connecting rod. When the finger bends, multiple segments of the geometrically shaped traction lines 405 form a wide constraint range, collaboratively constraining and controlling the movement of the finger segment. Linkages at the knuckles reduce the impact on finger bending. Geometric designs such as hexagons, quadrilaterals, and octagons distribute force evenly, reducing localized pressure concentration and ensuring stability and comfort when the finger bends. The hexagonal design, in particular, with its longer side close to the long side contour of the finger, better matches the natural shape of the finger, enhancing the uniformity of force distribution.

[0078] For example, the side lengths and angles of a hexagonal finger segment adjust accordingly when the finger bends. For instance, as the finger gradually bends from a straight position, the sides of the hexagon shorten and the angles change to accommodate the finger's bending shape. These adjustments are achieved through the structural characteristics of the hexagon; the multiple sides and vertices of the hexagon automatically rearrange themselves under stress to avoid overstretching or compression, thus maintaining the overall stability of the structure. Under different gripping postures, such as gripping a ball or a stick, the bending angle and stress points of the fingers will differ significantly. The hexagonal structure can flexibly adapt to these differences. When the fingers grip a round object, the vertices of the hexagonal structure expand outwards to distribute pressure, while when gripping a long and slender object, the sides of the hexagon become more compact to provide a stronger grip.

[0079] Specifically, the inner side of the finger mainly includes the following areas:

[0080] Finger pad: This is the softer, fleshier part at the tip of the finger, usually used to touch and sense the surface of objects.

[0081] Flexor tendon sheath: A protective structure that covers the outside of the flexor tendon and helps the tendon slide when the finger is bent.

[0082] Palmar skin and subcutaneous tissue: This layer includes skin and subcutaneous tissue, and is highly sensitive and flexible.

[0083] Palmar creases: The horizontal and vertical creases on the palmar side of the fingers, which increase finger dexterity and gripping ability.

[0084] On the inner side of the finger, there are also several major tendons and related muscles.

[0085] Flexor digitorum superficialis tendons: responsible for bending the middle joints of the fingers.

[0086] Flexor digitorum profundus tendons: responsible for flexion of the distal joints of the fingers.

[0087] Based on the nerve distribution and muscle group characteristics of the inner surface of the finger, the traction line 405 is placed on the back of the finger, reducing direct interference with the flexor and extensor muscles and ensuring that these muscle groups can contract and relax naturally to complete normal finger movements. The geometric structure promotes coordinated movement of the intrinsic muscle groups, improving the precision and flexibility of finger movements. Segmented control helps the intrinsic muscle groups better adapt to different finger movement requirements.

[0088] The structural design of the traction line 405 in this invention also protects the nerves of the finger, preventing nerve compression and damage. The traction line 405 is positioned on the back of the finger, avoiding nerve compression on the palmar and lateral sides of the finger. The sides and palmar sides of the finger are areas with dense sensory nerves; keeping these areas exposed ensures the tactile sensitivity and precision of the finger. Through the structural design of the linkage and geometry, the traction line 405 can provide precise force feedback, helping the user to perceive the mechanical state of the finger in real time during operation. This is crucial for the real-time adjustment and adaptation of the nervous system, improving the accuracy and coordination of finger movements.

[0089] The traction line 405 is designed with different structures based on the structural characteristics of the finger segments and joint segments, achieving a more significant control over the bending range of the traction finger. Specifically, taking the middle finger of an adult male as an example, the average length of the proximal phalanx (first phalanx) is approximately 4–5 cm. The average length of the middle phalanx (second phalanx) is approximately 3–5 cm. The average length of the distal phalanx (third phalanx) is approximately 2–3 cm, and the finger width is approximately 1.5 cm.

[0090] Based on the physiological characteristics of the middle finger, the structure of the first hexagonal traction line (the hexagonal connector near the base of the finger) is set as follows: long side L long1 = 2.5cm; short side L short1 =1.5cm. Initial small angle α1 = 60°; initial large angle β1 = 120°.

[0091] The structure for setting the second hexagonal traction line (the hexagonal connector near the fingertip) is as follows: Long side L long2 = 1.5cm; short side L short2 =1.5cm; initial small angle α2 = 60°; initial large angle β2 = 120°.

[0092] The length L of the first connecting rod between the first hexagonal traction wire and the second hexagonal traction wire link1 =5mm. The length L of the second connecting rod between the second hexagonal traction wire and the tactile electrode membrane 403 is 5mm. link2 =3mm.

[0093] Set the initial link angle: The angle of finger bending is θ. This indicates that the first link, in its initial position (unbent state), makes an angle of 15° with respect to a reference line (such as a horizontal line). Similarly, This indicates that the second link, in its initial position (unbent state), has an angle of 15° relative to a reference line (such as a horizontal line). The finger bending angle θ refers to the angle at which the finger bends from its initial upright position to a certain arc. This angle affects the angle change of the link.

[0094] Assuming the finger segment changes from fully extended to bent at 90 degrees, the change in the sides of the first hexagonal traction line can be represented by a geometric relationship:

[0095] ΔL long1 =L long1 ·(1-cos(θ)). ΔL short1 =L short1 ·(1-cos(θ)).

[0096] The change in the sides of the second hexagonal traction line can be expressed as:

[0097] ΔL long2 =L long2 ·(1-cos(θ)). ΔL short2 =L short2 ·(1-cos(θ)).

[0098] Assuming the driving force applied when the finger bends is F, we need to analyze the forces acting on each part.

[0099] The force on the first hexagonal traction wire is: F long1= F·cos(α1). F short1 =F·sin(α1).

[0100] The force on the second hexagonal traction wire is: F long2 = F·cos(α2). F short2 =F·sin(α2).

[0101] The force on the first link is: F link1 =F·cos(θ).

[0102] The force on the second link is: F link2 =F·sin(θ).

[0103] The finger bending angle θ is related to the geometric transformations and force changes of its various parts. Combining the geometric transformations and mechanical equations, we can obtain:

[0104] Assuming the force applied by the finger bending is F, the pressure P1 exerted by the first hexagonal traction line on the back of the finger can be expressed as:

[0105] Where A1 is the surface area of ​​the first hexagonal traction wire. The surface area of ​​the first hexagonal traction wire can be approximately expressed as: A1≈L long1 ·L short1 =2.5·1.5=3.75cm 2 .

[0106] Similarly, the pressure P2 exerted by the second hexagonal traction line on the back of the finger can be expressed as:

[0107] The surface area of ​​the second hexagon can be approximated as: A²≈L long2 ·L short2 =1.5·1.5=2.25cm 2 .

[0108] When the finger bends, the angle of the linkage changes accordingly.

[0109] The angle at which the first link bends is:

[0110] The angle at which the second link bends is:

[0111] When the finger bending angle θ changes to 60°, the change in the side length of the first hexagonal traction line is as follows:

[0112] ΔL long1 =2.5·(1-cos(60°))=2.5·0.5=1.25cm.

[0113] ΔL short1 =1.5·(1-cos(60°))=1.5·0.5=0.75cm.

[0114] When the finger bending angle θ changes to 60°, the change in the side length of the second hexagonal traction line is as follows:

[0115] ΔL long2 =1.5·(1-cos(60°))=1.5·0.5=0.75cm.

[0116] ΔL short2 =1.5·(1-cos(60°))=1.5·0.5=0.75cm.

[0117] The force on the first hexagonal traction wire is:

[0118] F long1 =F·cos(60°) =F·0.5.

[0119] The force on the second hexagonal traction wire is:

[0120] F long2 =F·cos(60°) =F·0.5.

[0121] The force on the first link is:

[0122] F link1 =F·cos(60°) =F·0.5;

[0123] The force on the second link is:

[0124]

[0125] The angle at which the first link bends is:

[0126] The angle at which the second link bends is:

[0127] To determine the driving force F applied by the drive mechanism, the force changes of each part during finger bending need to be considered. Under a 60° bend, the driving force applied by the drive mechanism should be sufficient to overcome the resistance of finger bending and maintain the stability of each part of the structure.

[0128] The driving force F of the drive mechanism should increase with the increase of the finger bending angle θ, because the resistance that needs to be overcome when bending is usually increasing non-linearly.

[0129] Assume the force that needs to be overcome when the finger is bent to θ is F. total .

[0130]

[0131] Assume F total =1ON, θ = 60°, then,

[0132]

[0133] Clearly, the driving force applied by the drive mechanism is adjusted in real time according to the bending angle of each finger. The pressure of the first and second hexagonal traction cables on the back of the finger also adapts to the change in driving force, avoiding stress on a single area of ​​the back of the finger.

[0134] As described above, the traction line 405 of the present invention is disposed on the back surface of the finger, including a knuckle segment and a finger segment. The finger segment is pre-printed into a geometrically shaped connector. The knuckle segment is shaped like a link. The geometrically shaped connectors are rotatably connected by the links. When the finger is tractioned to bend, the links maintain stable force transmission at different bending angles, thereby achieving a smooth and natural bending motion. The geometrically shaped connectors can evenly distribute force, reduce local pressure concentration, and ensure stability and comfort when the finger bends.

[0135] When the finger is fully bent, the force transmission principle of the geometrically shaped connector and link is as follows: the geometric design, such as a hexagon, forms a stable force distribution network through its multiple edges and vertices. When the finger bends, the geometrically shaped connector can evenly transmit and distribute pressure between the force points, reducing concentrated stress on individual joints. At the same time, the rotatable connection of the link allows the traction line 405 to adapt to the dynamic changes of finger bending, ensuring natural and smooth movement.

[0136] Through its linkage and geometric structural design, it offers numerous advantages in actuation. Firstly, through precise force control, the traction cable 405 can dynamically adjust the applied force based on the finger bending angle θ, ensuring that each finger joint receives appropriate pressure during bending. This precise control enables accurate finger movements, suitable for scenarios requiring high precision, such as virtual reality control and remote operation. It also boasts excellent adjustability, meeting diverse task requirements and finger postures, thus enhancing the user experience.

[0137] Specifically, appropriate pressure ensures the precision of finger flexion movements, allowing each joint to conform to the expected posture and angle during flexion, thus achieving precise finger movements. This effectively improves the accuracy and stability of operation. Appropriate pressure also helps prevent operational errors caused by excessive or insufficient force, protecting finger joints and muscle tissue, and reducing fatigue and discomfort. This is especially important for users who use the device for extended periods, enhancing overall user comfort and safety.

[0138] Furthermore, through the structural design of the linkages and geometry, the control mechanism can dynamically adjust the applied force according to the finger bending angle θ, exhibiting excellent adjustability. This means that the control mechanism can flexibly adapt to different task requirements and finger postures, providing stable and appropriate force support for both subtle movements and larger bends, thereby enhancing the user experience.

[0139] Finally, the control mechanism's real-time response and dynamic adjustment capabilities allow it to adjust the applied force based on the real-time state of the fingers, providing a fast-responding control experience. This dynamic adjustment ensures stability and consistency throughout different operating processes.

[0140] A power management module 407 is installed inside the outer shell frame 408 on the back of the hand. The power management module 407 includes a wireless charging power supply, and its overall power consumption is relatively low.

[0141] Preferably, the glove skeleton and haptic feedback unit 400 of the present invention are adjustable to accommodate different hand sizes and shapes. A three-dimensional coordinate sensor is mounted on the wrist shell 409 for detecting hand movements. The soft padding portion 411 of the palm is made of a soft, elastic material to ensure that the user feels comfortable force feedback. Preferably, an electromagnetic wave emitting component is disposed within the soft padding portion 411. The electromagnetic wave emitting component is used to implement haptic vibration via electromagnetic waves.

[0142] Preferably, the internal space of the joint frame 402 accommodates the pulley mechanism for adjusting the traction line 405.

[0143] Preferably, such as Figures 6 to 10 As shown, each finger area is equipped with a set of fine traction lines 405, which are connected to the mechanical frame of the glove via a pulley mechanism. Each traction line 405 is connected to an inertial sensor to sense finger movement.

[0144] Preferably, the space inside the joint frame 402 is also provided with a hidden wireless charging pad to provide power to the drive mechanism of the traction line 405, which can prevent the wiring from being messy and does not affect the aesthetics.

[0145] Examples of application scenarios for this invention are as follows.

[0146] S1: Command Reception: The user enters the virtual environment through the VR device, and the glove synchronizes with the VR system via wireless connection. When the user performs a specific action (such as grabbing, pushing, etc.) in the virtual environment, the VR system sends the corresponding command to the glove's control system.

[0147] S2: Data Processing: After receiving the command, the glove's control system immediately parses and converts it into drive signals. These signals will guide the glove's drive mechanism to perform the corresponding actions.

[0148] S3: Drive Mechanism Response: Based on signals from the control system, the glove's drive mechanisms (such as miniature vibrators, pneumatic actuators, etc.) begin to operate. At the finger contact points, these drive mechanisms generate tactile feedback through 3D-printed materials, simulating the texture, weight, and other characteristics of real-world objects.

[0149] S4: Haptic Feedback: Users experience the presence and characteristics of objects in the virtual environment through the tactile feedback of the gloves. This real-time feedback allows users to interact with the virtual environment more naturally.

[0150] S5: Feedback Loop: After receiving tactile feedback, the user adjusts their movements accordingly. Simultaneously, the VR system updates the virtual environment's state in real-time based on the user's actions and sends new commands to the glove's control system. This process forms a closed-loop feedback loop, making the interaction between the user and the virtual environment more natural and seamless.

[0151] For example, in the virtual reality (VR) game ALEX, players need to explore a virtual world full of interactive elements. To enhance the game's immersion and realism, VR force feedback gloves become an indispensable tool. This example will elaborate on the application of VR force feedback gloves in the ALEX game, particularly their performance in information interaction processes and adaptive changes in mechanical mechanisms.

[0152] The information exchange process is shown below.

[0153] S11: Command Reception and Synchronization

[0154] When players perform actions such as grabbing and pushing in the ALEX game, the VR system captures these actions and sends the corresponding instructions to the control system of the VR force feedback glove via wireless connection.

[0155] Once the glove control system receives the instruction, it will immediately analyze it and prepare to drive the corresponding mechanical mechanism to perform the action.

[0156] The haptic feedback is generated as shown below.

[0157] S12: Based on the instructions sent by the VR system, the glove's drive mechanisms (such as micro-vibrators, pneumatic actuators, etc.) begin to operate. These mechanisms generate tactile feedback through the finger contact parts of the 3D-printed material, simulating the texture, shape, and weight of objects in the game.

[0158] For example, when a player tries to grab a virtual stone, the glove will produce a corresponding sense of weight and roughness, enhancing the player's immersive experience.

[0159] The feedback loop and adjustments are shown below.

[0160] S13: After receiving tactile feedback from the gloves, players adjust their movements accordingly. This real-time feedback mechanism allows players to interact with the virtual environment more accurately.

[0161] The VR system updates the virtual environment in real time based on the player's actions and continues to send new instructions to the glove's control system, forming a closed-loop feedback loop.

[0162] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this invention, and these solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this invention is defined by the claims and their equivalents. This specification contains multiple inventive concepts; terms such as "preferredly," "according to a preferred embodiment," or "optionally" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept.

Claims

1. A haptic enhancement training system based on virtual reality, characterized in that, include: Virtual reality unit (100) interacts with virtual reality environment; A haptic feedback unit (400) is worn on the hand and provides feedback to the fingers in a way that applies traction force to the fingers, corresponding to the force of the grasping object in the virtual reality environment. The haptic feedback unit (400) is set on the glove frame in a hand-wearable form, with a control mechanism, a drive mechanism, a traction mechanism and a haptic feedback mechanism. The glove frame includes a back-side shell frame (401), a joint frame (402), a back-side middle shell frame (408), a wrist shell (409), a palm frame (410) and a soft padding part (411) in the palm. A frame drive mechanism is embedded in the frame. The frame drive mechanism adjusts the connection angle of the connectors between the back-side shell frame (401), the joint frame (402), the back-side middle shell frame (408) and the palm frame (410) based on the instructions of the frame control mechanism, so that the glove frame pulls the palm to move and applies force feedback to the palm. The traction wire (405) of the traction mechanism is set on the back surface of the finger, including the knuckle segment and the finger segment. The knuckle segment is connected by a linkage. The finger segment is pre-printed into a geometrically shaped connector. The geometrically shaped connector is rotatably connected by a linkage. The drive mechanism and the traction mechanism are connected by a pulley mechanism. The pulley mechanism is connected to a microcontroller (406). The drive mechanism changes the magnitude and direction of the force of each traction wire (405) in the traction mechanism by adjusting the pulley mechanism. An optical fiber sensor (404) is set at the end of the traction mechanism located at the fingertip. The tactile feedback mechanism is a tactile electrode membrane (403) worn on the fingertip. The tactile electrode membrane (403) applies physical stimulation to the hand to provide corresponding tactile feedback. The tactile electrode membrane (403) has a hollowed-out part. The processing unit (200) determines the contact point of the grasping object in the virtual reality environment, analyzes the force of the haptic feedback unit (400) on the finger based on the contact point of the grasping object, and sends information related to the force to the haptic feedback unit (400). The EEG signal acquisition unit (300) is communicatively connected to the processing unit (200). The EEG signal acquisition unit (300) acquires cognitive load brain nerve information of the head in real time. The processing unit (200) adjusts the feedback intensity of the force according to the cognitive load brain nerve information. The force is related to the physical characteristics of each contact point of the grasped object.

2. The virtual reality-based haptic enhancement training system according to claim 1, characterized in that, The haptic feedback unit (400) includes a control mechanism, a drive mechanism, a traction mechanism, and a haptic feedback mechanism. The control mechanism is communicatively connected to the drive mechanism, the traction mechanism, and the haptic feedback mechanism. The control mechanism constructs driving commands and tactile feedback commands based on information related to the applied force. The drive mechanism and the traction mechanism are connected and the traction direction and / or traction intensity of the traction mechanism located at the finger position are adjusted based on the drive command to push the hand knuckles to bend or extend. The tactile feedback mechanism is located at the fingertips and / or knuckles, and the tactile feedback mechanism applies physical stimulation to the hand based on the tactile feedback command to provide corresponding tactile feedback; The traction mechanism and the tactile feedback mechanism work together to allow the user to grasp the physical characteristics of the object based on the bending motion of the hand caused by traction and the tactile sensation.

3. The haptic enhancement training system based on virtual reality according to claim 1, characterized in that, When the user adjusts his / her hand movements based on tactile feedback, the virtual reality unit (100) updates the virtual reality environment based on the hand movements and sends updated information related to the force to the processing unit (200).

4. The haptic enhancement training system based on virtual reality according to claim 1, characterized in that, The haptic feedback mechanism in the haptic feedback unit (400) includes an inertial sensor and a motion tracking module. The inertial sensor is located at the finger joint and is used to collect information about the finger's bending movements. The motion tracking module is installed in the wrist housing (409) to collect hand movement information; The virtual reality unit (100) adjusts the hand model in the virtual reality environment based on the bending motion information of the fingers and the movement motion information of the hand, thereby forming realistic hand movements in the virtual reality environment.

5. The haptic enhancement training system based on virtual reality according to claim 1, characterized in that, The control mechanism is located on the back of the hand of the glove frame, and the drive mechanism is located near the metacarpophalangeal joints on the back of the hand. The traction mechanism connects the drive mechanism and the haptic feedback mechanism worn on the fingertip via a traction wire (405). The traction mechanism adaptively bends and stretches based on finger bending movements. The traction mechanism is equipped with inertial sensors at positions corresponding to the finger joints to collect the relative distance and pressure values ​​of each finger joint. The processing unit (200) detects hand movements in real time based on the relative distance and pressure value of each finger joint.

6. The virtual reality-based haptic enhancement training system according to claim 1, characterized in that, The tactile feedback mechanism in the tactile feedback unit (400) provides tactile feedback by applying vibration and / or pressure to the fingertips.

Images