A head-mounted haptic rendering method and implementation apparatus thereof

Abstract

This invention relates to a head-mounted haptic rendering method and its implementation device, belonging to the field of haptic feedback technology in human-computer interaction. It includes controlling m-linear vibrators positioned in the forehead region of a head-mounted support structure via a control module; generating corresponding driving signals according to a preset haptic rendering mode, the driving signals including driving frequency, driving voltage, and time delay parameters; controlling each linear vibrator to vibrate according to the driving signals to render a haptic effect with spatial direction and positional awareness in the user's forehead region. Advantages include achieving directional frictional haptic rendering, multi-position collision haptic positioning, enhanced haptic realism and immersive experience, flexible control, strong scalability, novel structure that is easy to implement and integrate, good engineering feasibility, and applicability in fields such as virtual reality, augmented reality, human-computer interaction, gaming, and remote interaction, demonstrating high application value and promotion potential.

Description

Technical Field

[0001] This invention belongs to the field of haptic feedback technology in human-computer interaction, and particularly relates to a head-mounted haptic rendering method and its implementation device. Background Technology

[0002] Haptic feedback technology is an important technology applied in human-computer interaction. It enables people to perceive and manipulate virtual objects through touch. Combined with audiovisual feedback technology, it helps people obtain richer information and feelings, improves the quality of interaction with the virtual world, and has broad application prospects in education, medical and health care, entertainment and games.

[0003] With the development of virtual reality, augmented reality, and immersive interactive technologies, haptic feedback has received increasing attention as an important means of enhancing user experience. However, existing haptic feedback devices mostly use a single vibration source for simple vibration cues, making it difficult to create complex tactile perceptions with directional and spatial positioning characteristics on the user's skin surface.

[0004] For example, existing devices typically cannot achieve a continuous tactile sensation from left to right or right to left in the forehead area, nor can they simulate the tactile sensation of collisions from different spatial locations. In addition, existing technologies lack precision in the coordinated control of multiple vibration units, resulting in a monotonous tactile effect and a weak sense of realism.

[0005] Existing research on head haptic rendering includes directional guidance, inertial force rendering, and illusion research, but there is still a lack of rendering of collision and friction haptic effects. There is obviously a demand for rendering these types of haptic effects.

[0006] Therefore, it is necessary to provide a head-mounted device and method that can achieve directional friction and multi-position collision tactile rendering through the coordinated control of multiple vibrators, so as to enhance the user's tactile experience. Summary of the Invention

[0007] This invention provides a head-mounted haptic rendering method and its implementation device to solve the problems of single haptic feedback, lack of spatial positioning and sense of direction, and imperfect rendering objects of head haptic feedback in the prior art.

[0008] The technical solution adopted by this invention includes the following steps:

[0009] (1) The m-linear vibrator set in the forehead area of ​​the headgear support structure is controlled by the control module;

[0010] (2) Generate a corresponding driving signal according to the preset haptic rendering mode, wherein the driving signal includes driving frequency, driving voltage and time delay parameters;

[0011] (3) Control each linear vibrator to generate vibration according to the drive signal to render a tactile effect with spatial direction and position in the user's forehead area, the tactile effect including friction tactile effect and collision tactile effect;

[0012] The control module achieves tactile perception in different directions and spatial positions by adjusting the driving frequency, driving voltage, and relative time delay of each linear vibrator.

[0013] The tactile sensation effect described in this invention includes:

[0014] When rendering the tactile effect of friction from left to right, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the right vibrator and the left vibrator of adjacent linear vibrators.

[0015] When rendering a frictional tactile effect from right to left, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the left and right vibrators of adjacent linear vibrators.

[0016] The driving signal whose frequency changes periodically with time, as described in this invention, is in the form of a triangular wave.

[0017] This invention selects m linear vibrators for friction effect rendering. The vibration frequency-time modulation signal of each linear vibrator is a triangular wave. For the linear vibrators, the vibration frequency-time function relationship is as follows:

[0018]

[0019] in, This is the minimum vibration frequency of the linear vibrator. Let k be the amplitude of the frequency change, and k be the discrete time step. Where is the time step, and T is the discrete period of the triangular wave. The initial phase is used to achieve a sense of vibration direction, which is achieved through the sequential occurrence of multiple mechanical vibrations at different locations.

[0020] In rendering the collision tactile effect, each linear vibrator vibrates at the same or similar frequency, and the amplitude of its driving voltage gradually decreases from the maximum value to the minimum value in each cycle.

[0021] When rendering a collision tactile effect at a certain point on the forehead, the vibrator at that location has the maximum voltage amplitude, the voltage amplitude of the vibrators on both sides decreases as the distance from the vibrator increases, and there is no time delay between adjacent linear vibrators.

[0022] This invention selects m linear vibrators for collision effect rendering. The vibration amplitude-time modulation signal of each linear vibrator exhibits a descending sawtooth waveform. For each linear vibrator, the vibration amplitude-time function relationship is as follows:

[0023]

[0024] in, Let k be the maximum amplitude of the sawtooth wave of the linear oscillator, and k be the discrete time step. Let T be the time step and T be the discrete period of the sawtooth wave. For the initial phase, The initial phase of mechanical vibration is kept constant, and the initial phase value is the same for all parts.

[0025] An apparatus for implementing a head-mounted haptic rendering method, comprising:

[0026] Headwear support structure;

[0027] m linear vibrators are installed in the forehead region of the headgear support structure;

[0028] The control module is electrically connected to the linear vibrator;

[0029] The control module is used to execute the head-mounted haptic rendering method.

[0030] The control module of this invention includes a signal generation module and a driving module;

[0031] The signal generation module uses a microcontroller to generate the target driving signal;

[0032] The drive module is used to output an AC drive signal according to the target drive signal to drive the linear vibrator to vibrate.

[0033] The device of the present invention further includes a communication module, which includes a host computer;

[0034] The host computer communicates with the microcontroller via a serial port to control the microcontroller to select the haptic rendering mode.

[0035] The present invention has the following beneficial effects:

[0036] 1. Achieve directional friction tactile rendering: Through time delay control and frequency modulation of multiple linear vibrators, a continuous friction tactile effect from left to right or from right to left can be formed in the user's forehead area. Compared with a single vibration mode, it improves the directionality and continuity of the tactile sensation.

[0037] 2. Achieve multi-position collision tactile positioning: By controlling the voltage distribution of different vibrators, collision tactile sensations can be simulated on the left, middle and right sides of the forehead, enabling users to perceive the spatial location of the tactile source and improving spatial positioning ability.

[0038] 3. Enhance tactile realism and immersive experience: Through the coordinated control of frequency, amplitude, and time delay, dynamic signal changes can be achieved, making tactile feedback closer to the real collision and friction process, thereby enhancing the user's immersion.

[0039] 4. Flexible control and strong expandability: Using a microcontroller as the signal generation core, along with a driver module and a communication module, the mode can be controlled through a host computer, supporting the switching and expansion of multiple haptic rendering modes.

[0040] 5. Novel structure, easy to implement and integrate: The overall structure adopts a head-mounted support structure combined with multiple linear resonant actuators, along with conventional control and drive circuits, which makes it easy to achieve hardware integration and has good engineering feasibility.

[0041] 6. Applicable to a variety of application scenarios: This invention can be applied to fields such as virtual reality, augmented reality, human-computer interaction, gaming and entertainment, and remote interaction, and has high application value and promotion potential. Attached Figure Description

[0042] Figure 1 This is an overall workflow diagram of the device used in this invention;

[0043] Figure 2 This is a schematic diagram of the host computer's haptic interface in custom mode;

[0044] Figure 3 This is a schematic diagram of the host computer's haptic interface in rendering mode;

[0045] Figure 4 This is a schematic diagram of the frequency-time control curve of a multi-channel vibration unit;

[0046] Figure 5 This is a schematic diagram of the voltage-time control curve of a multi-channel vibration unit;

[0047] Figure 6 This is a diagram illustrating how the device is worn;

[0048] Figure 7 This is a diagram of the device's hardware components. Detailed Implementation

[0049] Includes the following steps:

[0050] (1) The m-linear vibrator set in the forehead area of ​​the headgear support structure is controlled by the control module;

[0051] (2) Generate a corresponding driving signal according to the preset haptic rendering mode, wherein the driving signal includes driving frequency, driving voltage and time delay parameters;

[0052] (3) Control each linear vibrator to generate vibration according to the drive signal to render a tactile effect with spatial direction and position in the user's forehead area, the tactile effect including friction tactile effect and collision tactile effect;

[0053] The control module achieves tactile perception in different directions and spatial positions by adjusting the driving frequency, driving voltage, and relative time delay of each linear vibrator.

[0054] The tactile sensation effect described in this invention includes:

[0055] When rendering the tactile effect of friction from left to right, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the right vibrator and the left vibrator of adjacent linear vibrators.

[0056] When rendering a frictional tactile effect from right to left, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the left and right vibrators of adjacent linear vibrators.

[0057] The driving signal whose frequency changes periodically with time, as described in this invention, is in the form of a triangular wave.

[0058] This invention selects m linear vibrators for friction effect rendering. The vibration frequency-time modulation signal of each linear vibrator is a triangular wave. For the linear vibrators, the vibration frequency-time function relationship is as follows:

[0059]

[0060] in, This is the minimum vibration frequency of the linear vibrator. Let k be the amplitude of the frequency change, and k be the discrete time step. The time step is 75ms, and T is the discrete period of the triangular wave. As the initial phase, when this vibration signal is applied to the skin, It determines the minimum tangential force on the skin. The magnitude of the change in tangential force on the skin is determined by T, while the rate of change of tangential force on the skin is determined by T. It is a key variable for achieving a sense of vibration direction. By sequentially performing multiple mechanical vibrations at different locations, it creates the effect of a tangential force acting on the skin during motion.

[0061] In rendering the collision tactile effect, each linear vibrator vibrates at the same or similar frequency, and the amplitude of its driving voltage gradually decreases from the maximum value to the minimum value in each cycle.

[0062] When rendering a collision tactile effect at a certain point on the forehead, the vibrator at that location has the maximum voltage amplitude, the voltage amplitude of the vibrators on both sides decreases as the distance from the vibrator increases, and there is no time delay between adjacent linear vibrators.

[0063] To achieve the tactile effect of collision, each linear vibrator vibrates at the same or similar frequency, and its vibration amplitude changes in the form of a descending sawtooth wave over time.

[0064] This invention selects m linear vibrators for collision effect rendering. The vibration amplitude-time modulation signal of each linear vibrator exhibits a descending sawtooth waveform. For each linear vibrator, the vibration amplitude-time function relationship is as follows:

[0065]

[0066] in, Let k be the maximum amplitude of the sawtooth wave of the linear oscillator, and k be the discrete time step. The time step is 75ms, and T is the discrete period of the sawtooth wave. As the initial phase, when this vibration signal is applied to the skin, The magnitude of the normal force acting on the skin is determined by T, and the duration of the normal force acting on the skin is determined by T. To maintain a constant value, the initial phase of mechanical vibration is taken to be the same for all parts. This is because the collision process usually occurs briefly and the skin of each part has almost simultaneous tactile sensation.

[0067] An apparatus for implementing a head-mounted haptic rendering method, comprising:

[0068] Headwear support structure;

[0069] m linear vibrators are installed in the forehead region of the headgear support structure;

[0070] The control module is electrically connected to the linear vibrator;

[0071] The control module is used to execute the head-mounted haptic rendering method; it drives each linear vibrator to vibrate according to a preset haptic rendering signal to achieve friction haptic effect and collision haptic effect in the user's forehead area; and by adjusting the driving frequency, driving voltage and relative time delay of each linear vibrator, haptic perception in different spatial positions and directions can be achieved.

[0072] The control module of this invention includes a signal generation module and a driving module;

[0073] The signal generation module uses a microcontroller to generate target drive signals; the target signals include AC frequency control signals and AC voltage amplitude control signals for controlling the motor drive chip.

[0074] The drive module is used to output an AC drive signal according to the target drive signal to drive the linear vibrator to vibrate.

[0075] The device of the present invention further includes a communication module, which includes a host computer;

[0076] The host computer communicates with the microcontroller via a serial port to control the microcontroller to select the haptic rendering mode.

[0077] Through the above-described rendering method and implementation device, the present invention can achieve a tactile rendering effect with directional and spatial positioning characteristics in the forehead area, thereby enhancing the realism and immersion of tactile feedback.

[0078] The invention will be further illustrated by the following experimental examples.

[0079] A device for implementing a head-mounted haptic rendering method, the overall workflow of which is as follows: Figure 1 As shown, it includes the following steps:

[0080] (1) The user operates the host computer control interface on the PC unit and configures the serial port parameters that enable UARST communication with the microcontroller. The function of the PC unit is to communicate between the host computer and the slave computer and transmit instructions to the slave computer to realize the device working mode expected by the user.

[0081] (2) The drive signal generation unit is mainly implemented by the single-chip microcomputer minimum system. Its function is to generate the corresponding control signal to control the operation of the drive chip after receiving the instruction from the host computer.

[0082] (3) The drive unit is a motor drive chip that can provide AC current to the linear motor. After receiving the control signal generated by the lower-level machine, the drive unit can generate an AC signal with a certain frequency and effective value according to the requirements of the lower-level machine. This set of AC signals meets the design of the frequency / voltage-time control curve of the multi-channel vibration unit.

[0083] (4) The tactile actuator is a linear vibrator and its head carrier. After receiving the AC signal from the drive unit, the tactile actuator will vibrate at the corresponding frequency and amplitude according to the signal.

[0084] The specific method for using the host computer tactile interface in step (1) is as follows:

[0085] Select the specific values ​​in the parameter combination boxes of the serial port configuration bar according to the serial communication frame format of the lower-level machine. Once the serial port is opened, the parameters cannot be changed. The serial port configuration bar is as follows: Figure 2 , 3 As shown.

[0086] The control of the head-mounted haptic rendering device is divided into two modes: custom mode and rendering mode. The custom mode panel is as follows: Figure 2 As shown, users can configure specific vibration frequencies, intensities, and durations to make a linear motor vibrate through the interface. The rendering mode bar is as follows. Figure 3 As shown, users can select specific modes and intensity control devices in this section.

[0087] The instructions in steps (1) and (2) are: a hexadecimal number, the lower-level firmware program uses a switch statement structure to judge different conditions, enters the corresponding case branch according to the value of the instruction, and executes the corresponding control logic.

[0088] The frequency / voltage-time control curve of the multi-channel vibration unit in step (3) is as follows:

[0089] The frequency-time control curve of the multi-channel vibration unit is as follows: Figure 4 As shown, three linear vibrators are used. To achieve the frictional tactile effect, the control module controls the drive signal of each vibrator according to the set direction of movement. For the rendering of the head frictional tactile effect from left to right, the leftmost vibrator responds first, and the adjacent vibrators respond sequentially with a delay, thus forming a continuous tactile perception of movement; the opposite direction of friction uses the opposite time delay sequence. Figure 4 The image shows an example of a three-channel output vibration friction effect rendering from left to right, with the same minimum vibration frequency and amplitude. The linear vibrators controlled by channels 1, 2, and 3 are arranged sequentially, and the vibration frequency-time function relationship of each linear vibrator is as follows:

[0090]

[0091] in, The existence of a time delay of half a triangular wave cycle between two adjacent linear vibrators means that the next vibrator starts to vibrate when the previous vibrator reaches its maximum vibration, thus creating a directional tactile effect that rises and falls.

[0092] When achieving a collision-tactile effect, the voltage-time control curve of the multi-channel vibration unit is as follows: Figure 5As shown, each vibrator operates synchronously, with its drive signals having the same or similar frequencies, and its voltage amplitude changing over time in a descending sawtooth pattern. When rendering a head impact tactile effect at a certain location, the vibrator at that location has the maximum voltage amplitude, while the voltage amplitudes of the vibrators on both sides decrease as the distance from that vibrator increases.

[0093] Figure 5 The image shows an example of rendering the vibration collision effect of the three-channel output when a collision occurs at channel 1. The linear vibrators controlled by channels 1, 2, and 3 are arranged sequentially, and the vibration frequency-time function relationship of each linear vibrator is as follows:

[0094]

[0095] in, This is because the collision is a short process, and all points on the skin are simultaneously subjected to the force effect, so there is no time delay between the vibrator drive signals. This is determined by the distance between the vibrators.

[0096] The head-mounted haptic rendering device specifically includes: a PC unit, a microcontroller and its peripherals, a driving unit, and a haptic execution unit.

[0097] The host computer includes a PC unit. The user uses a haptic interface to issue hexadecimal numbers as commands to control the operating mode of the slave computer; the slave computer includes a drive signal generation unit and a drive unit, used to issue motor control signals;

[0098] (1) Select the lower computer running program through the upper computer tactile interaction interface, that is, select the specific tactile rendering mode;

[0099] (2) After receiving the instruction, the microcontroller outputs a drive signal that can control the input frequency and effective level time ratio of the drive unit;

[0100] (3) The drive unit outputs motor control signals with a certain AC frequency and effective voltage according to the requirements of the drive signal, drives the linear vibrator to vibrate at a certain frequency and amplitude, and realizes the tactile rendering of friction and collision through the overall vibration design.

Claims

1. A head-mounted haptic rendering method, characterized in that, Includes the following steps: (1) The m-linear vibrator set in the forehead area of ​​the headgear support structure is controlled by the control module; (2) Generate a corresponding driving signal according to the preset haptic rendering mode, wherein the driving signal includes driving frequency, driving voltage and time delay parameters; (3) Control each linear vibrator to generate vibration according to the drive signal to render a tactile effect with spatial direction and position in the user's forehead area, the tactile effect including friction tactile effect and collision tactile effect; The control module achieves tactile perception in different directions and spatial positions by adjusting the driving frequency, driving voltage, and relative time delay of each linear vibrator.

2. The head-mounted haptic rendering method according to claim 1, characterized in that: The tactile friction effect includes: When rendering the tactile effect of friction from left to right, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the right vibrator and the left vibrator of adjacent linear vibrators. When rendering a frictional tactile effect from right to left, the driving voltage of each linear vibrator remains constant, and the control module outputs a driving signal with a frequency that changes periodically with time to each linear vibrator. There is a preset time delay between the left and right vibrators of adjacent linear vibrators.

3. The head-mounted haptic rendering method according to claim 2, characterized in that: The driving signal, whose frequency changes periodically with time, is in the form of a triangular wave.

4. The head-mounted haptic rendering method according to claim 3, characterized in that: m linear vibrators are selected for friction effect rendering. The vibration frequency-time modulation signal of each linear vibrator is a triangular wave. For the linear vibrators, the vibration frequency-time function relationship is as follows: ； in, This is the minimum vibration frequency of the linear vibrator. Let k be the amplitude of the frequency change, and k be the discrete time step. Where is the time step, and T is the discrete period of the triangular wave. The initial phase is used to achieve a sense of vibration direction, which is achieved through the sequential occurrence of multiple mechanical vibrations at different locations.

5. The head-mounted haptic rendering method according to claim 1, characterized in that: When rendering the collision haptic effect, each linear vibrator vibrates at the same or similar frequency, and the amplitude of its driving voltage gradually decreases from the maximum value to the minimum value in each cycle.

6. The head-mounted haptic rendering method according to claim 5, characterized in that: When rendering a collision haptic effect at a certain point on the forehead, the vibrator at that location has the maximum voltage amplitude, the voltage amplitude of the vibrators on both sides decreases as the distance from the vibrator increases, and there is no time delay between adjacent linear vibrators.

7. The head-mounted haptic rendering method according to claim 6, characterized in that: m linear vibrators are selected for collision effect rendering. The vibration amplitude-time modulation signal of each linear vibrator exhibits a descending sawtooth waveform. For each linear vibrator, the vibration amplitude-time function relationship is as follows: ； in, Let k be the maximum amplitude of the sawtooth wave of the linear oscillator, and k be the discrete time step. Let T be the time step and T be the discrete period of the sawtooth wave. For the initial phase, The initial phase of mechanical vibration is kept constant, and the initial phase value is the same for all parts.

8. An apparatus for implementing the head-mounted haptic rendering method as described in any one of claims 1 to 7, characterized in that, include: Headwear support structure; m linear vibrators are installed in the forehead region of the headgear support structure; The control module is electrically connected to the linear vibrator; The control module is used to execute the head-mounted haptic rendering method.

9. The apparatus according to claim 8, characterized in that: The control module includes a signal generation module and a drive module; the signal generation module uses a microcontroller to generate target drive signals. The drive module is used to output an AC drive signal according to the target drive signal to drive the linear vibrator to vibrate.

10. The apparatus according to claim 9, characterized in that: The device further includes a communication module, which includes a host computer; the host computer communicates with the microcontroller via a serial port to control the microcontroller to select a haptic rendering mode.

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