Virtual reality locomotion method and apparatus with adaptive gait translation gains
By dynamically adjusting the translation gain in VR and combining it with the user's gait cycle and natural perturbations, the problem of the difference in movement speed between virtual and physical spaces in virtual reality is solved, which improves the user's immersion and comfort, broadens the perception threshold, and reduces the risk of motion sickness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TSINGHUA UNIVERSITY
- Filing Date
- 2024-12-31
- Publication Date
- 2026-05-15
AI Technical Summary
In existing VR movement methods, the difference in movement speed between virtual and physical spaces can easily exceed the perception threshold, leading to discomfort and reduced immersion. Furthermore, the constant translation gain limits the scope of application.
By combining the user's gait cycle and dynamic changes, the translation gain in the virtual reality environment is dynamically adjusted. The ratio of virtual to physical speed is adjusted by utilizing the user's natural perturbations, especially increasing the translation gain during the target period of the gait cycle and decreasing the translation gain during other periods.
It enhances user immersion and comfort, broadens the perception threshold of the difference in movement speed between virtual and physical spaces, reduces the likelihood of motion sickness, and improves the smoothness of the virtual reality experience.
Smart Images
Figure CN119987543B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of virtual reality technology, and in particular to a virtual reality movement method and apparatus with gait adaptive translation gain. Background Technology
[0002] Virtual Reality (VR) technology is a rapidly emerging technology that utilizes computer simulation to generate a three-dimensional virtual world. Users can interact with this virtual world through specialized devices such as head-mounted devices (HMDs), controllers, and motion capture systems. This technology has demonstrated enormous application potential in various fields, including gaming, education, healthcare, and architectural design, providing users with an immersive experience, as if they were actually there.
[0003] In VR experiences, high-fidelity graphics and realistic sound greatly enhance the user's immersion, enabling them to experience interactions and actions in the virtual world similar to those in the real world.
[0004] However, existing VR mobility methods are always limited by physical movement: the size of the virtual space is often larger than the user's physical space, or the shape and obstacle distribution of the physical space do not match the virtual space. This makes it necessary for users to pause or reposition themselves in the physical space when moving in the virtual world in order to avoid colliding with physical obstacles, which reduces the smoothness and comfort of the interaction.
[0005] To overcome this challenge, researchers have developed various VR walking solutions. The simplest and most direct method is to use traditional input devices, such as gamepads, keyboards, or mice, to control walking in the virtual world. This method is inexpensive, easy to learn, and suitable for most virtual reality applications. However, because the visual feedback is inconsistent with physical body perception, this method is highly likely to cause 3D motion sickness in users. Furthermore, since this method relies on button or joystick input and lacks direct connection with the user's body movements, it can make users feel overly controlled in the virtual world, affecting immersion.
[0006] Another solution is the omnidirectional treadmill, a device that allows users to stand on a fixed platform and control their movement in a virtual world through walking motions. However, omnidirectional treadmills are expensive and bulky, making them difficult to promote in home environments. Furthermore, while omnidirectional treadmills capture the user's stride movements, the lack of realistic ground feedback, as the user's steps are actually performed by sliding or stepping, can make the user feel unstable or uncoordinated.
[0007] Motion detection technology offers a simplified solution that requires no additional hardware. This technology enables movement in the virtual world by detecting simulated footwork movements (such as leg lifts or arm swings) performed by the user in place. However, this unnatural movement pattern can easily lead to user fatigue and reduce the accuracy of the movements.
[0008] To achieve more natural walking in virtual reality, the ideal solution is to allow users to walk realistically in physical space, with the physical pose of the virtual reality headset providing real-time feedback to the user's virtual pose. However, spatial factors such as the size and obstacle layout between physical and virtual spaces often conflict. The virtual world is typically a vast, open space, but users need to walk and explore it within a confined physical space, limited by walls, obstacles, and other constraints, significantly impacting the virtual reality experience.
[0009] Redirected Walking (RDW) technology utilizes errors in the human perception system to subtly manipulate the user's visual feedback, changing the ratio of movement speed, direction, and curvature between virtual and physical spaces without the user's awareness. This allows VR systems to support longer virtual walking distances within a limited physical space, while avoiding dizziness and discomfort caused by perceiving path curvature or motion scaling.
[0010] In Real-Time Warp Drive (RDW) technology, translation gain is crucial for optimizing the user experience. Translation gain adjusts the ratio of a user's walking speed in the virtual world to their walking speed in the physical world, mapping movement in real space to larger or smaller movements in virtual space. This facilitates exploration of the vast virtual environment while effectively preventing collisions. However, when applying translation gain, designers typically need to keep it within the user's perceptual threshold so that the difference between virtual and physical movement rates is imperceptible. When the difference between movement speed in virtual and physical space becomes too large, exceeding the user's perceptual threshold, the user may experience discomfort or lose immersion, realizing they are not in a real environment.
[0011] Currently, translation gain typically employs a constant-action approach, meaning that the ratio of the user's virtual movement rate to their physical movement rate is consistently adjusted throughout the user's gait cycle, without changing with the gait cycle. Because the translation gain acts constantly on the user's movement, users are more likely to detect inconsistencies between virtual and physical rates in relatively stable states (such as standing still or moving slowly), thus limiting the use of translation gain.
[0012] Therefore, how to dynamically adjust the ratio of virtual to physical speed by combining the user's gait cycle and dynamic changes, and make fuller use of the user's perceptual characteristics to improve immersion, is an important problem that urgently needs to be solved in the field of virtual reality. Summary of the Invention
[0013] This invention provides a virtual reality movement method and device with gait adaptive translation gain, which dynamically adjusts the ratio of virtual to physical speed by combining the user's gait cycle and dynamic changes, making fuller use of the user's perceptual characteristics to improve immersion, reducing the user's sensitivity to the difference between physical and virtual speed, allowing for a wider range of virtual space exploration, and without increasing the probability of motion sickness, thereby improving the user's overall comfort and immersion.
[0014] On one hand, the present invention provides a virtual reality movement method with gait adaptive translation gain, comprising: determining the natural perturbation in the gait cycle when the user walks naturally; dynamically adjusting the translation gain of the user in the virtual reality environment according to the natural perturbation in the gait cycle; wherein, the larger the natural perturbation, the larger the corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space.
[0015] Further, determining the natural disturbance in the gait cycle during natural walking includes: determining the target time period with the largest natural disturbance in the gait cycle during natural walking; correspondingly, dynamically adjusting the user's translation gain in the virtual reality environment based on the natural disturbance in the gait cycle includes: adjusting the user's translation gain in the virtual reality environment to increase the target translation gain during the target time period; adjusting the user's translation gain in the virtual reality environment to decrease the base translation gain outside the target time period; wherein the target translation gain is greater than the base translation gain.
[0016] Furthermore, determining the target time period with the greatest natural disturbance in the gait cycle during natural walking includes: acquiring the physical vertical movement speed value of the head-mounted display worn by the user; calculating the physical vertical movement acceleration of the user's head based on the physical vertical movement speed value; and determining the target time period with the greatest natural disturbance in the gait cycle during natural walking based on the physical vertical movement acceleration.
[0017] Further, the step of obtaining the physical vertical movement velocity value of the head-mounted display worn by the user includes: smoothing and stabilizing the physical vertical movement velocity value to obtain a smoothed and stabilized physical vertical movement velocity value; correspondingly, calculating the physical vertical movement acceleration of the user's head based on the physical vertical movement velocity value includes: calculating the physical vertical movement acceleration of the user's head based on the smoothed and stabilized physical vertical movement velocity value.
[0018] Further, based on the physical vertical movement acceleration, the target time period with the greatest natural disturbance in the gait cycle during the user's natural walking is determined, including: when the physical vertical movement acceleration of the user's head is greater than a first acceleration threshold, the target time period with the greatest natural disturbance in the gait cycle during the user's entry into natural walking is determined; when the physical vertical movement acceleration of the user's head is less than or equal to a second acceleration threshold, the target time period with the greatest natural disturbance in the gait cycle during the user exiting natural walking is determined; wherein, the first acceleration threshold is greater than or equal to the second acceleration threshold.
[0019] Furthermore, within the target time period, adjusting the user's translation gain in the virtual reality environment to increase the target translation gain includes: acquiring the user's physical horizontal movement velocity vector; determining the user's current target translation gain based on the physical horizontal movement velocity vector and the forward direction unit vector of the head-mounted display worn by the user; gradually increasing the current translation gain within the target time period with the target translation gain as the target; and adjusting the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space based on the gradually increasing current translation gain.
[0020] Further, determining the user's current target translation gain based on the physical horizontal movement velocity vector and the forward direction unit vector of the head-mounted display worn by the user includes: calculating the inner product of the physical horizontal movement velocity vector and the forward direction unit vector, and using the inner product as the user's physical horizontal movement forward velocity component; and determining the target translation gain based on the physical horizontal movement forward velocity component.
[0021] Furthermore, the step of adjusting the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space based on the gradually increasing current translation gain specifically includes: determining the user's current frame physical position and previous frame physical position in the physical space; calculating the user's current frame physical displacement based on the current frame physical position and previous frame physical position; obtaining the user's previous frame virtual position in the virtual space; and calculating the user's current frame virtual position in the virtual space based on the current frame physical displacement, the previous frame virtual position, and the current translation gain, so as to realize virtual reality movement.
[0022] Secondly, the present invention also provides a virtual reality mobile device with gait adaptive translation gain, comprising: a natural disturbance determination module for determining natural disturbances in the gait cycle when a user walks naturally; and a translation gain adjustment module for dynamically adjusting the translation gain of the user in the virtual reality environment based on the natural disturbances in the gait cycle; wherein, the larger the natural disturbance, the larger its corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space.
[0023] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the virtual reality movement method of gait adaptive translation gain as described above.
[0024] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the virtual reality movement method of gait adaptive translation gain as described above.
[0025] The gait-adaptive translation gain virtual reality mobility method provided by this invention determines the natural perturbations in the user's gait cycle during natural walking and dynamically adjusts the user's translation gain in the virtual reality environment based on these perturbations. The larger the natural perturbation, the larger the corresponding translation gain. The translation gain is used to adjust the ratio of the user's walking speed in virtual space to their actual walking speed in physical space. This method, by dynamically adjusting the translation gain according to the user's gait cycle, utilizes the user's own motion perturbations to reduce the inconsistency between the user's proprioception and visual perception, broadening the user's perception threshold for the difference in movement rates between virtual and physical spaces, without increasing the likelihood of motion sickness, thereby improving the user's overall comfort and immersion. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0027] Figure 1 This is a flowchart illustrating the virtual reality movement method with gait adaptive translation gain provided in an embodiment of the present invention.
[0028] Figure 2This is a detailed flowchart illustrating the virtual reality movement method with gait adaptive translation gain provided in an embodiment of the present invention.
[0029] Figure 3 This is a schematic diagram of the structure of the virtual reality mobile device with gait adaptive translation gain provided in an embodiment of the present invention.
[0030] Figure 4 This is a schematic diagram of the physical structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0032] It's important to note that for more natural walking in virtual reality, the ideal solution is to allow users to walk realistically in physical space, with the physical pose of the virtual reality headset providing real-time feedback to the user's virtual pose. However, spatial factors such as size and obstacle placement often conflict between physical and virtual spaces. Virtual worlds are typically open and expansive, but users need to walk and explore them within confined physical spaces, limited by walls and obstacles, significantly impacting the virtual reality experience.
[0033] RDW technology utilizes errors in the human perception system to subtly manipulate the user's visual feedback, changing the ratio of movement speed, direction, and curvature between virtual and physical spaces without the user's awareness. This enables VR systems to support longer virtual walking distances within a limited physical space, while avoiding dizziness and discomfort caused by perceiving path curvature or movement scaling.
[0034] In Real-Time Warp Drive (RDW) technology, translation gain is crucial for optimizing the user experience. Translation gain adjusts the ratio of a user's walking speed in the virtual world to their walking speed in the physical world, mapping movement in real space to larger or smaller movements in virtual space. This facilitates exploration of the vast virtual environment while effectively preventing collisions. However, when applying translation gain, designers typically need to keep it within the user's perceptual threshold so that the difference between virtual and physical movement rates is imperceptible. When the difference between movement speed in virtual and physical space becomes too large, exceeding the user's perceptual threshold, the user may experience discomfort or lose immersion, realizing they are not in a real environment.
[0035] Currently, the perception threshold for shift gain is generally between 0.86 and 1.26, which significantly limits the application range of shift gain. Further widening these thresholds would greatly improve the performance and application scope of RDW technology.
[0036] Currently, translation gain is typically applied in a constant manner, meaning that the translation gain is applied continuously throughout the entire walking process, without considering the user's walking state. Because the translation gain continuously affects the user's movement, users in relatively stable states (such as standing still or moving slowly) are more likely to detect inconsistencies between virtual and physical speeds, thus limiting the use of translation gain.
[0037] In view of this, the present invention proposes a virtual reality movement method based on gait adaptive translation gain, specifically, Figure 1 A flowchart illustrating the virtual reality movement method with gait adaptive translation gain provided in an embodiment of the present invention is shown.
[0038] like Figure 1 As shown, the method includes: S110, determining the natural disturbance in the gait cycle when the user walks naturally; S120, dynamically adjusting the translation gain of the user in the virtual reality environment according to the natural disturbance in the gait cycle; wherein, the larger the natural disturbance, the larger the corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space.
[0039] The following will provide a detailed description of steps S110-S120 and related steps.
[0040] S110, determine the natural perturbations in the gait cycle when the user walks naturally.
[0041] The gait cycle refers to the process a person goes through while walking, from the moment the heel of one foot strikes the ground until the heel of the same foot strikes the ground again. A complete gait cycle includes a stance phase and a swing phase. The stance phase accounts for approximately 60% of the entire gait cycle, during which at least one foot is in contact with the ground. The swing phase accounts for approximately 40% of the entire gait cycle, during which the foot does not strike the ground but swings forward in preparation for the next strike.
[0042] It is easy to understand that the vertical acceleration of a user's head is constantly changing during the gait cycle of natural walking. Therefore, this embodiment uses the physical vertical acceleration of the head-mounted display worn by the user as a standard to measure the magnitude of natural disturbances during the gait cycle of natural walking.
[0043] Based on the determination of natural disturbances in the gait cycle during natural walking in step S110, step S120 is further executed.
[0044] S120, dynamically adjust the translation gain of the user in the virtual reality environment according to the natural disturbance in the gait cycle; wherein, the larger the natural disturbance, the larger the corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space.
[0045] It is easy to understand that in redirected walking technology, translation gain is crucial for optimizing user experience. It is responsible for adjusting the ratio of the user's walking speed in the virtual world to their walking speed in the physical world, mapping movement in the real physical space to larger or smaller movements in the virtual space. This makes it easier for users to explore the vast virtual environment while effectively avoiding collisions.
[0046] In this embodiment, the adjustment of the user's translation gain in the virtual reality environment is positively correlated with the magnitude of the natural disturbance in the gait cycle. That is, the greater the natural disturbance in the gait cycle when the user walks naturally, the greater the corresponding adjustment of the user's translation gain in the virtual reality environment.
[0047] It is worth mentioning that, since the natural perturbations in the gait cycle change in real time, the adjustment process of the translation gain of the user in the virtual reality environment in this embodiment is also dynamic.
[0048] It should be noted that steps S110 and S120 will be elaborated in more detail in the following embodiments, and will not be described in detail here.
[0049] In this embodiment, the natural perturbations in the user's gait cycle during natural walking are determined, and the translation gain of the user in the virtual reality environment is dynamically adjusted based on these perturbations. The larger the natural perturbation, the larger the corresponding translation gain. The translation gain is used to adjust the ratio of the user's walking speed in virtual space to their actual walking speed in physical space. This method dynamically adjusts the translation gain based on the user's gait cycle, utilizing the user's own motion perturbations to reduce the inconsistency between the user's proprioception and visual perception, broadening the user's perception threshold for the difference in movement rates between virtual and physical spaces, without increasing the likelihood of motion sickness, thereby improving the user's overall comfort and immersion.
[0050] Figure 2 A detailed flowchart of the virtual reality movement method with gait adaptive translation gain provided in an embodiment of the present invention is shown.
[0051] like Figure 2As shown, the method includes: S210, determining the target time period with the greatest natural disturbance in the gait cycle when the user walks naturally; S220, within the target time period, adjusting the translation gain of the user in the virtual reality environment to increase the target translation gain; S230, outside the target time period, adjusting the translation gain of the user in the virtual reality environment to decrease the base translation gain; wherein, the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space, and the target translation gain is greater than the base translation gain.
[0052] The following will provide a detailed description of steps S210-S230 and related steps.
[0053] S210, determine the target time period with the greatest natural disturbance in the gait cycle when the user is walking naturally.
[0054] It's easy to understand that during a user's gait cycle while walking naturally, the vertical acceleration of their head is constantly changing. When a user is walking naturally during the period of greatest natural disturbance in the gait cycle (usually when the heel of the foot contacts the ground during a step), the vertical acceleration of their head will show a significant peak.
[0055] Therefore, in this embodiment, the physical vertical movement acceleration of the head-mounted display worn by the user is used as the standard to measure the magnitude of natural disturbance in the gait cycle when the user walks naturally, and the time period with the greatest natural disturbance in the gait cycle when the user walks naturally is determined in this way, which is the target time period.
[0056] Specifically, the system first acquires the physical vertical movement velocity value of the user's head-mounted display. Then, it calculates the physical vertical movement acceleration of the user's head based on this velocity value, and compares this acceleration with a pre-set acceleration threshold. If the physical vertical movement acceleration is higher than the pre-set threshold, the user is identified as being within the target time period, which is considered the period of greatest natural disturbance in their gait cycle during natural walking. Conversely, if the acceleration is lower, the user is identified as not being within the target time period, which is considered the period of greatest natural disturbance in their gait cycle during natural walking.
[0057] The preset acceleration threshold can be set according to actual needs, and no specific limitation is made here.
[0058] After determining the target time period with the greatest natural disturbance in the gait cycle during the user's natural walking in step S210, step S220 or step S230 is further executed.
[0059] S220, during the target time period, adjust the translation gain of the user in the virtual reality environment to increase the translation gain towards the target.
[0060] It should be noted that in redirected walking technology, translation gain is crucial for optimizing user experience. It is responsible for adjusting the ratio of the user's walking speed in the virtual world to their walking speed in the physical world, mapping movement in the real physical space to larger or smaller movements in the virtual space. This makes it easier for users to explore the vast virtual environment while effectively avoiding collisions.
[0061] What is easy to understand is that after determining the target period with the greatest natural disturbance in the gait cycle when the user walks naturally, a larger translation gain is applied to this target period than to other periods, that is, the ratio of the movement rate in virtual space to the movement rate in actual physical space.
[0062] This embodiment aims to gradually increase the translation gain of the user in the virtual reality environment within a target time period, with the target translation gain as the objective. The specific value of the target translation gain can be adjusted according to actual circumstances and is not specifically limited here.
[0063] S230, outside the target time period, adjust the translation gain of the user in the virtual reality environment to reduce it towards the base translation gain.
[0064] What is easy to understand is that after determining the target period when the user’s gait cycle has the greatest natural disturbance during natural walking, a translation gain smaller than the target translation gain is applied to other periods outside the target period, that is, the ratio of the movement rate in virtual space to the movement rate in actual physical space.
[0065] In this embodiment, during periods other than the target time period, the translation gain of the user in the virtual reality environment will be gradually reduced, with the base translation gain as the target. The specific value of the base translation gain can be adjusted according to actual circumstances and is not specifically limited here.
[0066] However, it should be noted that the target value of gradually increasing the translation gain within the target time period must be greater than the target value of gradually decreasing the translation gain outside the target time period. In other words, the target translation gain must be greater than the base translation gain.
[0067] It should also be noted that steps S220 and S230 in this embodiment are two parallel steps. At any given time, only step S220 or step S230 will be executed, depending on the current time period.
[0068] Based on the above, this embodiment applies a larger translation gain during the period when the body's natural disturbance is greatest in the gait cycle when the user is walking naturally, and applies a smaller translation gain during the period when the body's disturbance is relatively small in the gait cycle. It uses the user's natural disturbance when walking to mask the application of translation gain, making the use of translation gain less noticeable.
[0069] In this embodiment, a target time period with the greatest natural disturbance in the user's gait cycle during natural walking is determined. Within this target time period, the user's translation gain in the virtual reality environment is adjusted to increase towards the target translation gain. Outside the target time period, the translation gain in the virtual reality environment is adjusted to decrease towards the base translation gain. The translation gain is used to adjust the ratio of the user's walking speed in virtual space to their actual walking speed in physical space, and the target translation gain is greater than the base translation gain. This method dynamically adjusts the translation gain based on the user's gait cycle, utilizing the user's own motion disturbances to reduce the inconsistency between the user's proprioception and visual perception. This broadens the user's perception threshold for the difference in movement rates between virtual and physical spaces without increasing the likelihood of motion sickness, thereby improving the user's overall comfort and immersion.
[0070] Furthermore, the gait-adaptive translation gain virtual reality mobility method provided in this embodiment of the invention is a general virtual reality mobility solution. It requires no additional equipment other than the user's head-mounted display, has no special restrictions on virtual scenes and tasks, and can be applied to various types of virtual reality applications such as single-person VR applications, multi-person VR applications, and dynamic VR scenes. It can also be combined with existing virtual reality mobility technologies such as redirected walking to jointly improve the efficiency of virtual reality mobility technology.
[0071] Based on the above embodiments, the process of determining the target time period with the greatest natural disturbance in the gait cycle during a user's natural walking will be described in detail below.
[0072] Determining the target period of maximum natural disturbance in the gait cycle during a user's natural walking includes: obtaining the physical vertical movement velocity value of the head-mounted display worn by the user; calculating the physical vertical movement acceleration of the user's head based on the physical vertical movement velocity value; and determining the target period of maximum natural disturbance in the gait cycle during a user's natural walking based on the physical vertical movement acceleration.
[0073] It's easy to understand that this can first be obtained through VR trackers. The physical vertical movement speed value of the head-mounted display at any given time is set to... And use the double exponential smoothing method to adjust the physical vertical movement velocity value Perform smoothing. Definition Let be a smoothing factor, and let its value be 0.05. The physical vertical movement speed value of the head-mounted display worn by the user at any time The processes of single exponential smoothing and double exponential smoothing are shown in equations (1)-(2) respectively.
[0074] (1).
[0075] (2).
[0076] In equations (1)-(2), and They represent Physical vertical movement speed value of the head-mounted display at all times The values after single-exponential smoothing and double-exponential smoothing. and These are the previous time moments ( (Time) Physical vertical movement speed value of the head-mounted display The values after single-exponential smoothing and double-exponential smoothing are used for smoothing. The physical vertical movement speed value of the head-mounted display at any given moment. This is immediately after the method starts (i.e.,...). When, due to and It does not exist. and 0 can be used as a substitute.
[0077] The physical vertical movement velocity value after double exponential smoothing in equation (2) The physical vertical movement speed value of the head-mounted display after smoothing and stabilization.
[0078] It should be noted that smoothing and stabilizing the physical vertical movement speed values of the user's head-mounted display can remove noise from the data, thereby helping to more accurately distinguish the various stages of the user's stride and apply gait synchronization translation gain in subsequent processes.
[0079] Subsequently, based on the smoothed and stabilized physical vertical movement velocity values, the physical vertical movement acceleration of the user's head is calculated.
[0080] Specifically, let's set This represents the physical vertical movement velocity of the head-mounted display at the current moment, after smoothing and stabilization. The physical vertical movement velocity of the head-mounted display after smoothing and stabilization at the previous moment is given by [value]. The time interval between the previous moment and the current moment is [value]. Then the physical vertical movement acceleration of the user's head at the current moment The calculation equation is as follows (3).
[0081] (3).
[0082] Furthermore, based on the physical vertical acceleration, the target period of maximum natural disturbance in the user's gait cycle during natural walking is determined. Specifically, if the physical vertical acceleration of the user's head is greater than a first acceleration threshold, the user is determined to be in the target period of maximum natural disturbance in the gait cycle during natural walking; if the physical vertical acceleration of the user's head is less than or equal to a second acceleration threshold, the user is determined not to be in the target period of maximum natural disturbance in the gait cycle during natural walking.
[0083] In detail, during the gait cycle of natural human walking, the vertical acceleration of the head is constantly changing. When humans are walking naturally, during the period of greatest natural disturbance in the gait cycle (usually when the heel of the foreleg touches the ground during the step), the vertical acceleration of the head will show a significant peak.
[0084] It should be noted that the first acceleration threshold and the second acceleration threshold can be set to the same value or different values; no specific restrictions are imposed here.
[0085] For example, in one specific embodiment, this peak value was determined experimentally to be greater than Therefore, both the first acceleration threshold and the second acceleration threshold are set to... .
[0086] set up For users The physical vertical acceleration of the user's head at any given moment, if Then, determine the period when the user is in the gait cycle with the greatest natural disturbance during natural walking, i.e., the target period; if If the user is not in the period of greatest natural disturbance in the gait cycle during natural walking, then other periods outside the target period are identified.
[0087] In another specific embodiment, the first acceleration threshold is set to Set the second acceleration threshold to This setting makes the switching criteria more directional.
[0088] set up For users The physical vertical acceleration of the user's head at any given moment, in terms of the overall process: initially, The process involves identifying periods outside the target timeframe where the user's gait cycle exhibits the greatest natural disturbance during natural walking; subsequently... The process involves identifying the period during which the user experiences the greatest natural disturbance in their gait cycle during natural walking, i.e., the target period; then, The system still identifies the period during which the user experiences the greatest natural disturbance in their gait cycle during natural walking, which is the target period. Finally... This involves identifying periods when the user is not in the gait cycle with the greatest natural disturbance during natural walking, i.e., other periods outside the target time period.
[0089] In this embodiment, the physical vertical movement speed of the user's head-mounted display is acquired, and the physical vertical movement acceleration of the user's head is calculated based on this speed. Then, based on this acceleration, a target time period with the greatest natural disturbance in the user's gait cycle during natural walking is determined. Within this target time period, the translation gain of the user in the virtual reality environment is adjusted to increase towards the target gain; outside the target time period, the translation gain is adjusted to decrease towards the baseline gain. The translation gain is used to adjust the ratio of the user's walking speed in virtual space to their actual walking speed in physical space, with the target translation gain being greater than the baseline gain. This method dynamically adjusts the translation gain based on the user's gait cycle, utilizing the user's own motion disturbances to reduce the inconsistency between proprioception and visual perception, broadening the user's perception threshold for the difference in movement rates between virtual and physical spaces, without increasing the likelihood of motion sickness, thereby improving the user's overall comfort and immersion.
[0090] Based on the above embodiments, the application process of translation gain at different time periods will be described in detail below.
[0091] In one embodiment, adjusting the translation gain of a user in a virtual reality environment to increase the target translation gain within a target time period includes: acquiring the user's physical horizontal movement velocity vector; determining the user's current target translation gain based on the physical horizontal movement velocity vector and the forward unit vector of the head-mounted display worn by the user; gradually increasing the current translation gain within the target time period with the target translation gain as the target; and adjusting the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space based on the gradually increasing current translation gain.
[0092] It's easy to understand that this can be obtained through VR trackers. The physical horizontal movement velocity vector of the head-mounted display at any given time is set as follows: And the velocity vector was smoothed using a double exponential smoothing method. Perform smoothing. Definition Let be a smoothing factor, and let its value be 0.05. The physical horizontal movement velocity vector of the head-mounted display worn by the user at any given time The processes of single-exponential smoothing and double-exponential smoothing are shown in equations (4)-(5) respectively.
[0093] (4).
[0094] (5).
[0095] In equations (4)-(5), and They represent Physical horizontal movement velocity vector of the head-mounted display at all times The values after single exponential smoothing and double exponential smoothing. and These are the previous time moments ( (Moment) Physical horizontal movement velocity vector of the head-mounted display The values after single-exponential smoothing and double-exponential smoothing are used for smoothing. The physical horizontal movement speed value of the head-mounted display at any given time. This is the value immediately after the method starts (i.e.,...). When, due to and It does not exist. and The zero vector can be used as a substitute.
[0096] The physical horizontal shift vector in equation (5) after double exponential smoothing As the physical horizontal movement velocity vector of the head-mounted display after smoothing and stabilization.
[0097] It should also be noted that smoothing and stabilizing the physical horizontal movement velocity vector of the user's head-mounted display can remove noise from the data, thereby maintaining visual consistency and stability when applying gait synchronization translation gain, providing the user with a more comfortable experience.
[0098] Subsequently, based on the physical horizontal movement velocity vector and the forward unit vector of the head-mounted display worn by the user, the dot product of the physical horizontal movement velocity vector and the forward unit vector is calculated.
[0099] The unfolding ground, set for The physical horizontal movement velocity vector at each moment, after smoothing and stabilization, is obtained through a VR tracker. Forward direction unit vector of the head-mounted display at all times ( Length of the module (1.0). Calculated... and Angle between two vectors The dot product of the smoothed and stabilized physical horizontal movement velocity vector and the forward unit vector of the user's head-mounted display is then calculated. As shown in equation (6).
[0100] (6).
[0101] in, In a physical sense, it represents the component of the physical horizontal movement velocity vector, after smoothing and stabilization, in the forward direction of the head-mounted display worn by the user. When the value is positive and large, it indicates that the user is moving forward; when... When the absolute value is small or negative, it indicates that the user is stationary, moving laterally, or moving backward.
[0102] Next, determine the user's current target translation gain.
[0103] Specifically, the target translation gain can be a fixed value or an uncertain value that changes in real time with the user's horizontal forward speed; no specific limitation is made here.
[0104] For example, in one specific embodiment, the target translation gain The value is 2.0, at which point the user's movement speed in the virtual space is 2.0 times that in the actual physical space.
[0105] Preferably, in another specific embodiment, the target translation gain The forward velocity component can be moved according to the user's physical level. The calculation is as follows, and the specific calculation process can be found in the following formula (7).
[0106] (7).
[0107] In equation (7), the forward velocity component of the physical horizontal movement It is the inner product of the physical horizontal movement velocity vector (after smoothing and stabilization) and the forward direction unit vector of the head-mounted display worn by the user, that is, the component of the horizontal movement velocity of the head-mounted display worn by the user in the forward direction. The specific calculation formula can be found in the above formula (6). The adjustment coefficient can be set to 1.05 in this embodiment.
[0108] It should be noted that, during the target time period, by correlating the target translation gain with the user's horizontal forward velocity, the target translation gain can be controlled within the user's perception threshold, ensuring that the difference between virtual and physical movement rates is not perceived by the user. After determining the target translation gain, the ratio of movement rate in virtual space to movement rate in actual physical space is further increased gradually during the target time period, with the target translation gain as the target, to achieve virtual reality movement.
[0109] Specifically, the system determines the user's current frame physical position and previous frame physical position in the physical space; calculates the user's current frame physical displacement based on the current frame physical position and previous frame physical position; obtains the user's previous frame virtual position in the virtual space; and calculates the user's current frame virtual position in the virtual space based on the current frame physical displacement, the previous frame virtual position, and the current translation gain that gradually increases with the target translation gain as the target, so as to realize virtual reality movement.
[0110] In detail, firstly, a VR tracker can be used to obtain and record the user's current frame physical position and the previous frame physical position in the physical space, and the current frame physical position is recorded as... The physical location of the previous frame is denoted as This allows us to calculate the user's physical displacement in the current frame, and the physical displacement of the current frame. .
[0111] Subsequently, the user's virtual position in the previous frame in the virtual space is obtained. The target translation gain is calculated based on the period of greatest natural perturbation during the gait cycle of a user's natural walking. To achieve the goal, gradually increase the current translation gain. (i.e., the ratio of movement speed in virtual space to movement speed in actual physical space), and calculate the user's current frame virtual position in virtual space. See equations (8)-(9) below for details.
[0112] (8).
[0113] (9).
[0114] Equation (8) shows the calculation of the progressively increasing current translation gain. In Equation (8), This represents the translation gain of the previous frame, with the target translation gain being the target translation gain. , and , A coefficient indicating how quickly the gain changes. For the set control parameters, For the user's physical horizontal movement forward velocity component. Coefficient The value of is related to the user's physical horizontal forward velocity component. Correspondingly, the larger the forward velocity component of the user's horizontal movement, the better. The larger. During the target period, The value is 0.5.
[0115] In equation (8), It not only covers the target translation gain, but also the current translation gain that is gradually increased with the target translation gain as the target.
[0116] Then, the position of the virtual camera used to capture the user's field of view in the virtual space is moved to... To achieve virtual reality mobility.
[0117] In another embodiment, outside of the target time period, the translation gain of the user in the virtual reality environment is adjusted to reduce it towards the base translation gain.
[0118] Specifically, during periods outside the target time when the natural perturbation is greatest in the gait cycle during natural walking, the base translation gain is used. To achieve this, gradually reduce the current translation gain (i.e., the ratio of movement speed in virtual space to movement speed in actual physical space).
[0119] In other words, the user's physical position in the current frame and the previous frame can be obtained and recorded using a VR tracker. That is, the physical position of the current frame is denoted as... The physical location of the previous frame is denoted as It can calculate the user's current frame physical displacement. .
[0120] Determine the user's virtual position in the previous frame in the virtual space as The user's current frame virtual position in the virtual space can be seen in the following equation (10).
[0121] (10).
[0122] In equation (10), Because it was outside the target time period, It covers not only the base translation gain, but also the current translation gain that is progressively reduced with respect to the base translation gain, where the translation gain target is the base translation gain. .
[0123] Similarly, However, outside the target time period, The value is 0.05.
[0124] Move the virtual camera position in the virtual space used to capture the user's field of view to the current frame's virtual position. To achieve virtual reality mobility.
[0125] Optionally, the base translation gain If we set it to 1.0, the user's movement speed in the virtual space is equal to their movement speed in the actual physical space.
[0126] In this embodiment, the translation gain of the user in the virtual reality environment is adjusted during the target time period to increase the target translation gain, and then adjusted outside the target time period to decrease the base translation gain. The translation gain is used to adjust the ratio of the user's walking speed in the virtual space to their actual walking speed in the physical space, and the target translation gain is greater than the base translation gain. This method dynamically adjusts the translation gain based on the user's gait cycle, utilizing the user's own motion disturbances to reduce the inconsistency between the user's proprioception and visual perception, broadening the user's perception threshold for the difference in movement rates between virtual and physical spaces, without increasing the likelihood of motion sickness, thereby improving the user's overall comfort and immersion.
[0127] Corresponding to the virtual reality movement method with gait adaptive translation gain described in the embodiments above, the present invention also proposes a virtual reality movement device with gait adaptive translation gain.
[0128] Specifically, Figure 3 A schematic diagram of the structure of the virtual reality mobile device with gait adaptive translation gain provided in an embodiment of the present invention is shown.
[0129] like Figure 3 As shown, the device includes: a natural disturbance determination module 310, used to determine the natural disturbance in the gait cycle when the user walks naturally; and a translation gain adjustment module 320, used to dynamically adjust the translation gain of the user in the virtual reality environment according to the natural disturbance in the gait cycle; wherein, the larger the natural disturbance, the larger the corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space.
[0130] In this embodiment, the natural disturbance determination module 310 determines the natural disturbance in the user's gait cycle during natural walking, and the translation gain adjustment module 320 dynamically adjusts the user's translation gain in the virtual reality environment based on the natural disturbance in the gait cycle. The larger the natural disturbance, the larger the corresponding translation gain. The translation gain is used to adjust the ratio of the user's walking speed in virtual space to their actual walking speed in physical space. By dynamically adjusting the translation gain according to the user's gait cycle, this device reduces the inconsistency between the user's proprioception and visual perception by utilizing the user's own motion disturbance, broadening the user's perception threshold for the difference in movement rates between virtual and physical spaces, without increasing the probability of motion sickness, thereby improving the user's overall comfort and immersion.
[0131] It should be noted that the virtual reality mobile device with gait adaptive translation gain provided in the embodiments of the present invention can be referred to in correspondence with the virtual reality mobile method with gait adaptive translation gain described in the above embodiments, and will not be repeated here.
[0132] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include: a processor 410, a communication interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call logical instructions in the memory 430 to execute a virtual reality movement method with gait adaptive translation gain. This method includes: a natural disturbance determination module for determining natural disturbances in the gait cycle when the user walks naturally; and a translation gain adjustment module for dynamically adjusting the user's translation gain in the virtual reality environment based on the natural disturbances in the gait cycle; wherein, the larger the natural disturbance, the larger its corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in virtual space to the user's actual walking speed in physical space.
[0133] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0134] On the other hand, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a virtual reality mobility method for gait adaptive translation gain provided by the methods described above. This method includes: a natural disturbance determination module for determining natural disturbances in the gait cycle of a user during natural walking; and a translation gain adjustment module for dynamically adjusting the translation gain of the user in the virtual reality environment based on the natural disturbances in the gait cycle; wherein, the larger the natural disturbance, the larger its corresponding translation gain, and the translation gain is used to adjust the ratio of the user's walking speed in virtual space to the user's actual walking speed in physical space.
[0135] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0136] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.
[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A virtual reality movement method with gait adaptive translation gain, characterized in that, include: Identify the natural perturbations in the gait cycle during a user's natural walking; Dynamically adjust the translation gain of the user in the virtual reality environment based on the natural perturbations in the gait cycle; The greater the natural disturbance, the greater the corresponding translation gain. The translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space. The determination of natural disturbances in the gait cycle during a user's natural walking includes: determining the target time period during which the natural disturbances are greatest in the gait cycle during a user's natural walking; Accordingly, dynamically adjusting the user's translation gain in the virtual reality environment based on natural perturbations in the gait cycle includes: During the target time period, adjust the translation gain of the user in the virtual reality environment to increase the translation gain towards the target. Outside of the target time period, adjust the user's translation gain in the virtual reality environment to reduce it towards the base translation gain; Wherein, the target translation gain is greater than the base translation gain; The process of determining the target time period with the greatest natural disturbance in the gait cycle during a user's natural walking includes: Obtain the physical vertical movement speed value of the head-mounted display worn by the user; Calculate the physical vertical movement acceleration of the user's head based on the physical vertical movement velocity value; Based on the physical vertical movement acceleration, the target time period with the greatest natural disturbance in the gait cycle during the user's natural walking is determined.
2. The virtual reality movement method with gait adaptive translation gain according to claim 1, characterized in that, The process of obtaining the physical vertical movement speed value of the head-mounted display worn by the user then includes: The physical vertical movement speed value is smoothed and stabilized to obtain the smoothed and stabilized physical vertical movement speed value; Accordingly, based on the physical vertical movement velocity value, the physical vertical movement acceleration of the user's head is calculated, including: Calculate the physical vertical movement acceleration of the user's head based on the smoothed and stabilized physical vertical movement velocity value.
3. The virtual reality movement method with gait adaptive translation gain according to claim 1, characterized in that, Based on the physical vertical acceleration, the target time period with the greatest natural disturbance in the gait cycle during natural walking is determined, including: When the physical vertical movement acceleration of the user's head is greater than the first acceleration threshold, determine the target period with the greatest natural disturbance in the gait cycle when the user enters natural walking. If the physical vertical movement acceleration of the user's head is less than or equal to the second acceleration threshold, determine the target period of the gait cycle with the greatest natural disturbance when the user exits natural walking.
4. The virtual reality movement method with gait adaptive translation gain according to claim 1, characterized in that, During the target time period, adjust the user's translation gain in the virtual reality environment to increase the translation gain towards the target, including: Obtain the user's physical horizontal movement velocity vector; Based on the physical horizontal movement velocity vector and the forward direction unit vector of the head-mounted display worn by the user, determine the user's current target translation gain; Within the target time period, with the target translation gain as the objective, the current translation gain is gradually increased; The ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space is adjusted based on the gradually increasing current translation gain.
5. The virtual reality movement method with gait adaptive translation gain according to claim 4, characterized in that, Based on the physical horizontal movement velocity vector and the forward unit vector of the head-mounted display worn by the user, determine the user's current target translation gain, including: Calculate the dot product between the physical horizontal movement velocity vector and the forward direction unit vector, and use the dot product as the user's physical horizontal movement forward velocity component; The target translation gain is determined based on the forward velocity component of the physical horizontal movement.
6. The virtual reality movement method with gait adaptive translation gain according to claim 4, characterized in that, The step of adjusting the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space based on the gradually increasing current translation gain specifically includes: Determine the user's physical location in the current frame and the physical location in the previous frame; Calculate the user's physical displacement in the current frame based on the physical position of the current frame and the physical position of the previous frame; Get the user's virtual position in the previous frame within the virtual space; The user's virtual position in the current frame is calculated based on the physical displacement of the current frame, the virtual position of the previous frame, and the current translation gain, so as to realize virtual reality movement.
7. A virtual reality mobile device with gait adaptive translation gain, characterized in that, include: The natural disturbance determination module is used to determine the natural disturbances in the gait cycle when a user walks naturally. The translation gain adjustment module is used to dynamically adjust the translation gain of the user in the virtual reality environment based on the natural perturbations in the gait cycle. The greater the natural disturbance, the greater the corresponding translation gain. The translation gain is used to adjust the ratio of the user's walking speed in the virtual space to the user's actual walking speed in the physical space. The determination of natural disturbances in the gait cycle during a user's natural walking includes: determining the target time period during which the natural disturbances are greatest in the gait cycle during a user's natural walking; Accordingly, dynamically adjusting the user's translation gain in the virtual reality environment based on natural perturbations in the gait cycle includes: During the target time period, adjust the translation gain of the user in the virtual reality environment to increase the translation gain towards the target. Outside of the target time period, adjust the user's translation gain in the virtual reality environment to reduce it towards the base translation gain; Wherein, the target translation gain is greater than the base translation gain; The process of determining the target time period with the greatest natural disturbance in the gait cycle during a user's natural walking includes: Obtain the physical vertical movement speed value of the head-mounted display worn by the user; Calculate the physical vertical movement acceleration of the user's head based on the physical vertical movement velocity value; Based on the physical vertical movement acceleration, the target time period with the greatest natural disturbance in the gait cycle during the user's natural walking is determined.
8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the virtual reality movement method with gait adaptive translation gain as described in any one of claims 1 to 6.
9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the virtual reality movement method with gait adaptive translation gain as described in any one of claims 1 to 6.