Collision prevention for virtual reality systems

Technology for virtual reality device for avoiding collisions during a virtual reality experience. The virtual reality device comprises an accelerometer configured to sense an acceleration of the virtual reality device and a gyroscope configured to sense an angular velocity and orientation of the virtual reality device. Further comprising one or more proximity sensors configured to detect an object. A processor may be configured to receive data from the one or more proximity sensors and predict a potential collision between a user of the virtual reality device and the object detected by the one or more proximity sensors. An alarm may generate an alert regarding the potential collision.

BACKGROUND

The demand for virtual reality (VR) devices and systems has been increasing in recent years. VR is created by computer technologies that generate images, sounds and other sensations to create an environment. The environment may be three dimensional and immersive and may simulate a user's physical presence in the environment. A user may be able to interact with the space and objects in the environment using display screens or projectors and other devices. VR devices provide a unique user experience that may require a user to physically move in order to navigate or interact with the VR environment. Because a user is typically immersed in the VR environment, it may not be possible for the user to appreciate their actual location with respect to surrounding objects in a real-world environment in which the VR is being used.

DESCRIPTION OF EMBODIMENTS

Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of layouts, distances, network examples, etc., to convey a thorough understanding of various invention embodiments. One skilled in the relevant art will recognize, however, that such detailed embodiments do not limit the overall inventive concepts articulated herein, but are merely representative thereof.

As used in this written description, the singular forms “a,” “an” and “the” include express support for plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a proximity sensor” includes a plurality of such sensors.

Reference throughout this specification to “an example” means that a particular feature, structure, or characteristic described in connection with the example is included in at least one invention embodiment. Thus, appearances of the phrases “in an example” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

As used herein, comparative terms such as “increased,” “decreased,” “better,” “worse,” “higher,” “lower,” “enhanced,” and the like refer to a property of a device, component, or activity that is measurably different from other devices, components, or activities in a surrounding or adjacent area, in a single device or in multiple comparable devices, in a group or class, in multiple groups or classes, or as compared to the known state of the art. For example, VR device that employs technology that warns a user of proximity to objects in their physical surrounding may have “increased” safety, as compared to a VR system that does not employ such technology.

As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint. However, it is to be understood that even when the term “about” is used in the present specification in connection with a specific numerical value, that support for the exact numerical value recited apart from the “about” terminology is also provided.

As used herein, the term “circuitry” can refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some aspects, the circuitry can be implemented in, or functions associated with the circuitry can be implemented by, one or more software or firmware modules. In some aspects, circuitry can include logic, at least partially operable in hardware.

As used herein, the term “processor” can include general purpose processors, specialized processors such as VLSI, FPGAs, or other types of specialized processors, as well as base band processors used in transceivers to send, receive, and process wireless communications.

Example Embodiments

A user of a virtual reality (VR) device or system may participate in an immersive interactive experience such that the user's senses, such as vision and hearing, is occupied by the VR experience and the user may not perceive what is happening in the real world physical environment. This may lead to the user unintentionally colliding with objects in the physical environment surrounding the user. Exemplary objects may be, but are not limited to, furniture, walls, doors, people, pets, etc. To this end, various invention embodiments encompass a VR device that incorporates a sensing mechanism to prevent potential collisions. For example, one or more proximity sensors may be mounted or otherwise associated with a VR headset, controller, helmet, glove, or other wearable portion of the VR device or system. The proximity sensor is then able to detect objects in the physical setting surrounding the user of the VR device. Detection of an object is then used to determine a potential collision between the user of the VR device and the object, and an alert can be triggered or generated to alert the user to the potential collision so that the user may avoid the collision. It should be appreciated that the collision prevention techniques of the technology using proximity sensors may be extended to other fields such as mixed reality.

FIG. 1is a diagram illustrating an embodiment of a virtual reality device configured to predict a potential collision. The virtual reality device100may include wearable components or devices to interface with the user. The virtual reality device100can have any form that can be worn, held by, attached to, or otherwise share a spatial proximity or location with a user. Non-limiting examples of various form factors include eyeglasses, goggles, a headset, a helmet, a hand held game controller, a hand held game console, gloves, footwear, bracelets, wrist devices, a tablet computer, a smart phone or similar structure, an earpiece, a ring, etc. For example, the virtual reality device100may include more than one component such as a headset102as well as an interface device110, which may be a wearable or hand held component. The virtual reality device100may include one or more output interfaces such as speakers120to output sound or audible signals, haptic feedback122to provide tactile output such as vibrations, and/or a display124to display visual information, graphics, or video. The virtual reality device100may include an accelerometer114to measure acceleration of the virtual reality device100or a component thereof. For example, each of the headset102and the interface device110may have an accelerometer. The virtual reality device100may also include a gyroscope116to determine an orientation of the virtual reality device100or a component thereof. For example, each of the headset102and the interface device may have a gyroscope.

The virtual reality device100may include a processor106, which may be a central processing unit (CPU), an application-specific instruction set processor (ASIP), or other processor. The processor106may process data for the VR outputs and inputs as well as software associated with the virtual reality device100. It should be appreciated that portions or components of the virtual reality device100may be permanently attached or mounted to one another or may be detachable or separate. The different components may communicate with one another over wired or wireless connections. For example, the interface device110may be a handheld controller that is connected to the processor106by a wireless connection. In one aspect, the headset102includes a detachable device such as a smart phone or tablet that includes the display124and the processor106. The virtual reality device100may also include a communication device126to communicate with external devices such as local or remote computer systems, gaming consoles, other VR devices, etc. The communication device126may use wired or wireless connections and may communication via wireless protocols such as Wi-Fi or Bluetooth and may communicate over the internet.

In one aspect, the virtual reality device100may include one or more proximity sensors such a proximity sensor104and proximity sensor112. A virtual reality device100may have several proximity sensors and may have the proximity sensors placed in various locations or on different components of the virtual reality device100. For example, the headset102may have one or more proximity sensors such as proximity sensor104and the interface device110may have one or more proximity sensors such as the proximity sensor112. The proximity sensor may be one of several different types of proximity sensors. A virtual reality device100may have more than one type or combinations of proximity sensors. The proximity sensors may be, but are not limited to, light detection and ranging (LIDAR) sensors, radio detection and ranging (RADAR) sensors, radio wave sensors, infrared (IR) sensors, capacitive sensors, inductive sensors, and ultrasound sensors.

In one aspect, the proximity sensor is capable of detecting or sensing an object128within a given range of the proximity sensor. The object128may be an object (e.g. a known object or an unknown or “foreign” object) within proximity to the user of the virtual reality device100. For example, the object128may be furniture, a wall, a person, a pet, a door, etc. The user of the virtual reality device100may potentially collide with the object128and the potential collision may be difficult for the user to detect because the user's vision, hearing, and other senses may be occupied by the immersive experience provided by the virtual reality device100. The proximity sensors may be ultrasonic sensors that propagate a sound through the air and receive or detect the sound reflected off a surface of the object. The amount of time between when the sound was sent and when the reflected sound is received can be used to determine the distance of object from the proximity sensor. The proximity sensors may also be able to detect relative velocities or accelerations for the object128compared to the proximity sensor. The data generated by the proximity sensors is sent to the processor106, which uses the data to predict a potential collision between the user of the virtual reality device100and the object128. In one aspect, the proximity sensors send raw data to the processor106, which uses the data to determine the position, relative velocity, and/or relative acceleration of the object128.

In one aspect, after the processor106predicts a potential collision, the processor106triggers a notification (e.g. an alarm)118to alert the user of the virtual reality device100regarding the potential collision. The virtual reality device100may have more than one notification or alarm. For example, alarm118may generate one or more types of alerts such as an audible alert via the speakers120, a visual alert via the display124, or a tactile alert via haptic feedback122. The virtual reality device100may have more than one display, speaker, or haptic feedback for alerting the user to the potential collision. For example, the headset102may have the ability to provide haptic feedback by tapping the user on the forehead while the interface device110may be a wrist band that also has the ability to provide haptic feedback. The alarm118may alert the user with different alerts depending on different types or classes of potential collision. For example, if the potential collision with the object128is determined to have a high likelihood of success, then the alert may be different than a potential collision that has a low likelihood of success. In one aspect, a predicted potential collision may trigger an alert and after an interval of time, if the potential collision becomes more likely then the alert may become more persistent. For example, an initial alert may be a an audible chirp and if the potential collision becomes more likely than the chirp may repeat at a louder volume or may repeat several times at intervals closer in time. In a different aspect, as a potential collision becomes more likely an alert may change types such that an initial alert may be a haptic feedback while a subsequent alert may be a visual alert. Nearly any sequence or combination can be used. In one aspect, the alert may be more insistent or more invasive if the object has a relative velocity compared to the object that makes the potential collision likely as opposed to a potential collision where the object appears to be static and only the user is moving.

In one aspect, a velocity of the object may also be estimated by applying a certain chirp signal. The following is a description for velocity estimation. A generated chirp signal may be defined in equation (1):
x1(t)=sin(α1et)  (1)

where t is time, and α1is damping factor. Upon reflection of the signal from the obstacle, the reflected signal can be modeled by equation (2):
x2(t)=sin((α1+α2t)et)+n(t)  (2)

Where α2is the changed damping factor, which is a function of the velocity of the approaching (or receding) obstacle, and n(t) is the ambient additive white Gaussian noise (AWGN) afflicting the transmitted and reflected signal. α2s directly proportional to the velocity of the obstacle, whereas the time lapse between the generated signal and reflected signal (i.e. time-of-flight, ttof) is proportional to the distance from the obstacle.

The following set of equations may be used to estimate the velocity of the approaching object. First derivative of x1(t) is given by equation (3):
x1′(t)=α1etcos(α1et)  (3)

First derivative of x2(t) is given by equation (4)
x2′(t)=cos((α1+α2t)et).(et(α1+α2t)+α2et)+n′(t)  (4)

From the above expressions for x2′(t) and x1′(t), and under the assumption α2<<α1follows that equation (5):
x2′(t)−x1′(t)=cos((α1+α2t)et).α2et+α2t etcos(α1et)+n′(t)  (5)

Or equation (8):

In this manner, α2can be found to estimate the velocity of the approaching obstacle. Alternatively, if the time-of-flight ttofs known, then α2can be estimated as follows. For example, if it is known that for any given t in equation (9):
x2(t+ttof)−x1(t)≈0  (9)

Or in equation (10):
x2′(t+ttof)−x1′(t)≈0  (10)

From equation (10) it follows that at t=0 for equation (11):
x2′(ttof)−x1′(0)≈0  (11)

Since α1and ttofare known, the transcendental equation (12) can be solved numerically for α2. A numerical illustration of estimating α2may be performed by generating a signal for duration of 10 s with parameters α1=0.1 and α2=0.01. By using equation (8) for α2, the value of α2can be estimated to be 0.0101. That amounts to a 1% error in α2stimation. In one aspect, when additive noise is added, then a suitable noise-deconvolution or low pass filtering may be performed on the received signal to remove the noise affects prior to using equation (8) to estimate α2.

FIG. 2is a diagram illustrating a virtual reality system configured to predict a potential collision. A virtual reality system200may include some features or capabilities of the virtual reality device100ofFIG. 1. In one aspect, the virtual reality system200may be composed of distinct devices. For example, a headset202, an interface device208, and a processor216may be distinct devices from one another that communicate via a communication device206associated with the headset202, a communication device212associated with the interface device208, and a communication device220associated with the processor216. The headset202, the interface device208, and the processor216may communicate with one another over wired or wireless channels. The processor216may be located physically proximate or remote to the headset202and the interface device208. The headset202may be coupled to or otherwise associated with a proximity sensor204and the interface device208may be coupled to or otherwise associated with a proximity sensor210. The proximity sensor204and the proximity sensor210may be used to detect an object218, which is an object in proximity to the virtual reality system200.

FIG. 3is a diagram of components of a virtual reality device configured to predict a potential collision.FIG. 3depicts a headset302, which may have some or all of the features and capabilities of the headset102ofFIG. 1or as elsewhere described herein.FIG. 3also depicts hand controller304and hand controller306, which may have some or all of the capabilities and features of interface device110ofFIG. 1or as elsewhere described herein. The headset302is depicted as including proximity sensors308,310,312,314,316,318,320, and322. The hand controller304is depicted as including proximity sensors324,326,328, and330. The hand controller306is depicted as including proximity sensors332,334,336, and338. It should be appreciated that that the headset302, the hand controller304, and the hand controller306may comprise any number of proximity sensors. For example, the headset302may include 2, 4, 6, or 8 proximity sensors. In one aspect, the headset302, the hand controller304, or the hand controller306may have more than one proximity sensors where the proximity sensors each have a direction or field of view and the proximity sensors are mounted on different surfaces of the headset302, the hand controller304, or the hand controller306such that the proximity sensors face different directions. For example, the headset302may have proximity sensors308,310,312,314,316, and318that face forward and the proximity sensors320and322face to one side of the headset302while other proximity sensors not depicted may face an even different direction. In one aspect, the proximity sensors328,330,332, and334face a top direction of the hand controller304and the hand controller306while the proximity sensors324,326,336, and338face a side direction.

FIG. 4is a diagram illustrating a proximity sensor detecting an object.FIG. 4depicts a proximity sensor408, which is a proximity sensor capable of propagating or generating a transmission404such as a transmission wave. The transmission404may be a sound, an electromagnetic radiation, light, or other transmission. The transmission404may impinge on a surface of an object406, which is a physical object that may be the same as object102ofFIG. 1. The transmission404may be reflected off the object406as an echo408. The echo408may be transmitted back to the proximity sensor408where it is received. The proximity sensor408may employ light detection and ranging (LIDAR), radio detection and ranging (RADAR), radio waves, infrared (IR), capacitive sensors, inductive sensors, and ultrasound. In one aspect, the proximity sensor408employs ultrasound where the transmission404transmits a sound at time t1, and the sound will be propagating through the air and reflected back by the object406and picked up by the receiver of the proximity sensor408at time t2, so the distance between the proximity sensor408and the object406is found using equation (13):
D=sound speed*(t2−t1)/2  (13)

In one aspect, a controller or microcontroller is employed to trigger the proximity sensor408to send out the transmission404. In one aspect, the proximity sensor408send out an eight cycle burst of ultrasound at 40 kilohertz. In one aspect, the range of error for distance detection of the distance between the proximity sensor408and the object406is less than five percent. In one aspect, the proximity sensor408can detect distances of the object406with a range of two centimeters to several meters. This range may encompass the size of an average living room or other space where a virtual reality device is employed by a user.

FIG. 5is a diagram illustrating predetermined thresholds for predicting collisions.FIG. 5depicts a device502, which may be a virtual reality device such as the virtual reality device100ofFIG. 1, or as otherwise described herein. The device502may be associated with or used by a user504. In one aspect, a threshold512surrounds the device502and/or the user504. The threshold512may be a predefined distance such as a radius, a sphere, or a half sphere that surrounds the device502and/or the user504. The threshold512may be defined to be the same size as the reach of body parts of the average size user of the virtual reality device or slightly larger. For example, the typical human arm length may be 25 inches (˜64 cm), so that the threshold512may be defined as 70 cm. The processor of the device502may be configured such that predicted potential collisions within the threshold512will not trigger an alert based on the potential collision. This may be done so that a body part of the user will not trigger a potential collision alert. In one aspect, the device502may prompt the user for measurements of body parts such as arm length. This actual measurement may then be used to determine the distances for the threshold512for the particular user.

In one aspect, an outer threshold510may also be defined. The technology may employ both the threshold512and the outer threshold510or may use one without the other. The outer threshold510may be parallel is shape to the threshold512only larger. Objects detected outside of the outer threshold510may not trigger an alert for a potential collision because the likelihood of actual collision may be trivial. The size of the outer threshold510may be determined based on historical data a virtual reality device being used. The outer threshold510may change based on the software or game being used in conjunction with the virtual reality device. The outer threshold510may be user defined. In one aspect, the object506may be detected within the outer threshold510and will thus trigger an alert if a potential collision is detected, whereas the object508may be detected outside of the outer threshold510and may not trigger an alert even if a potential collision is detected.

In one aspect, the technology operates with the proximity sensors of the device502to prevent the device502from triggering a false alert when the device502senses or detects the ground or floor as an object. For example, a gyroscope such as gyroscope116ofFIG. 1may determine an orientation of the device502. The device502may have more than one component such as a headset or a hand controller. Each of the components may have one or more gyroscopes used to determine orientation of each of the components. Before a user operates the device502for use in activities such as gaming, the device502may be calibrated by prompting the user for information regarding the user's height. The distance from the ground to each component of the device502may be estimated taking into account the user's height and the orientation determination made by the gyroscope. In the methods of the present technology, the distance from the ground to each component of the device502may change dynamically during operation of the device502. The method may dynamically calculate the distance from the ground to each component of the device502during operation of the device502in real-time. The dynamically changing distance may then be set as a threshold such that when the floor is detected by the proximity sensor, the floor is ignored as a potential collision with the user. This threshold may operate similar to outer threshold510.

FIG. 6is a diagram illustrating a field of view for a proximity sensor. A proximity sensor may have a field of view or angle-of-view (AOV) that limits what objects the proximity sensors can detect. The field of view may be directional such that a proximity sensor may not be able to detect objects in a 360 degree field of view. For example a field of view for a proximity sensor may be 30 degrees. This limitation may be overcome by employing more than one proximity sensors to ensure that a full field of view is employed by the technology to detect all potential collisions. The environment600depicts proximity sensor602held a height606above the ground604. The proximity sensor604may be held above the ground because the user is standing while holding the headset or interface device that the proximity sensor602is mounted on. For example, the lateral distance614depicts the outer range or distance for an object that the proximity sensor602can detect. For a nominal person of height 5 feet, 7 inches, i.e. 5.58 feet, a field of view610with an angle608of 30 degrees makes it possible to detect obstacles of height612of 0.96 feet or higher (from the ground604) at a lateral distance614of eight feet or farther as shown.

FIG. 7depicts a flowchart of process700of a method for avoiding collisions during a virtual reality experience. The method can be executed as instructions on a machine, where the instructions are included on at least one computer readable medium or one non-transitory machine-readable storage medium. In one embodiment, the virtual reality device100ofFIG. 1or the virtual reality system200ofFIG. 2, or any other device or system recited herein, is configured to carry out the steps process700. Moreover, the devices and components depicted inFIGS. 1-2may be employed to carry out the steps of process700. The method can include the operation of: detecting an object in proximity to a virtual reality device via one or more proximity sensors associated with the virtual reality device, as in block710. The method can include the operation of: determining a position and relative velocity of the object, as in block720. The method can include the operation of: predicting a potential collision between a user of the virtual reality device and the object, as in block730. The method can include the operation of: generating an alarm regarding the potential collision, as in block740. It should be appreciated that the steps of process700may not include all of the steps depicted nor in the order in which they are depicted.

FIG. 8depicts an exemplary system upon which embodiments of the present disclosure may be implemented. For example, the system ofFIG. 8may be a computer system or virtual reality device. The system can include a memory controller802, a plurality of memory804, a processor806, and circuitry808. The circuitry can be configured to implement the hardware described herein for virtual reality device100ofFIG. 1or as otherwise recited herein. Various embodiments of such systems forFIG. 8can include smart phones, laptop computers, handheld and tablet devices, CPU systems, SoC systems, server systems, networking systems, storage systems, high capacity memory systems, or any other computational system.

The system can also include an I/O (input/output) interface810for controlling the I/O functions of the system, as well as for I/O connectivity to devices outside of the system. A network interface can also be included for network connectivity, either as a separate interface or as part of the I/O interface810. The network interface can control network communications both within the system and outside of the system. The network interface can include a wired interface, a wireless interface, a Bluetooth interface, optical interface, and the like, including appropriate combinations thereof. Furthermore, the system can additionally include various user interfaces, display devices, as well as various other components that would be beneficial for such a system.

The system can also include memory in addition to memory804that can include any device, combination of devices, circuitry, and the like that is capable of storing, accessing, organizing and/or retrieving data. Non-limiting examples include SANs (Storage Area Network), cloud storage networks, volatile or non-volatile RAM, phase change memory, optical media, hard-drive type media, and the like, including combinations thereof.

The processor806can be a single or multiple processors, and the memory can be a single or multiple memories. The local communication interface can be used as a pathway to facilitate communication between any of a single processor, multiple processors, a single memory, multiple memories, the various interfaces, and the like, in any useful combination.

The system can also include a user interface812a graphical user interface for interacting with the user. The system can also include a display screen814for displaying images and the user interface812. The system can also include proximity sensors816for detecting objects.

EXAMPLES

The following examples pertain to specific technology embodiments and point out specific features, elements, or steps that may be used or otherwise combined in achieving such embodiments.

In one example there is provided, virtual reality device, including

an accelerometer configured to sense an acceleration of the virtual reality device;

a gyroscope configured to sense an angular velocity and orientation of the virtual reality device;

one or more proximity sensors configured to detect an object;

a processor configured to:receive data from the one or more proximity sensors; andpredict a potential collision between a user of the virtual reality device and the object detected by the one or more proximity sensors; and

an alarm configured to generate an alert regarding the potential collision.

In one example of a virtual reality device, the alarm is further configured to generate the alert only for potential collisions outside of a predefined distance surrounding the virtual reality device such that body parts of the user will not trigger the alert as the potential collision.

In one example of a virtual reality device, the processor is further configured to:

estimate a distance between a floor and the virtual reality device based on data regarding the orientation of the virtual reality device obtained from the gyroscope;

define an outer threshold based on combining the distance between the floor and the virtual reality device with data regarding physical dimensions of a user; and

prevent the alarm from generating an alert if the potential collision is out of range of the outer threshold.

In one example of a virtual reality device, the distance between the floor and the virtual reality device dynamically changes during operation of the virtual reality device and the outer threshold is dynamically changed with the distance between the floor and the virtual reality device.

In one example of a virtual reality device, the one or more proximity sensors are ultrasonic sensors configured to propagate a sound through air and to receive the sound after reflecting off the object.

In one example of a virtual reality device, the one or more proximity sensors are selected from the group of proximity sensors consisting of: light detection and ranging (LIDAR) sensors, radio detection and ranging (RADAR) sensors, radio wave sensors, infrared (IR) sensors, capacitive sensors, inductive sensors, and ultrasound sensors.

In one example of a virtual reality device, the alert is selected from the group of alters consisting of: an audible alert, a visual alert, a vibration, and haptic feedback.

In one example of a virtual reality device, the one or more proximity sensors are mounted to a headset wearable by the user.

In one example of a virtual reality device, the one or more proximity sensors are mounted to a handheld controller.

In one example of a virtual reality device, the virtual reality device further comprising a communication device to communicate with an external device regarding the potential collision.

In one example of a virtual reality device, the one or more proximity sensors are further configured to determine a velocity or acceleration of the object relative to the virtual reality device.

In one example of a virtual reality device, the virtual reality device is employed for mixed reality settings and the alarm generates the alert in the mixed reality setting.

In one example of a virtual reality device, a first proximity sensor is mounted to a component of the virtual reality device with a first angle of view and a second proximity sensor is mounted to the component of the virtual reality device with a second angle of view that encompasses a different field of view compared to the first angle of view.

In one example there is provided, a virtual reality system, including

an interface device comprising:an accelerometer configured to sense an acceleration of the interface device;a gyroscope configured to sense an angular velocity and orientation of the interface device;a first proximity sensor configured to detect an object;a first communication device to send data regarding the object from the first proximity sensor to a processor;

a headset device comprising:a second proximity sensor configured to detect the object; anda second communication device to send data regarding the object from the second proximity sensor to the processor;

the processor configured to predict a potential collision between a user of the interface device and the object detected by the first proximity sensor and the second proximity sensor; and

an alarm configured to generate an alert regarding the potential collision.

In one example of a virtual reality system, the alarm is further configured to generate the alert only for potential collisions outside of a predefined distance surrounding the interface device or the headset device such that body parts of the user will not trigger the alert as the potential collision.

In one example of a virtual reality system, the processor is further configured to:

estimate a distance between a floor and the virtual reality device based on data regarding the orientation of the virtual reality device obtained from the gyroscope;

define an outer threshold based on combining the distance between the floor and the virtual reality device with data regarding physical dimensions of a user; and

prevent the alarm from generating an alert if the potential collision is out of range of the outer threshold.

In one example of a virtual reality system, the distance between the floor and the virtual reality device dynamically changes during operation of the virtual reality device and the outer threshold is dynamically changed with the distance between the floor and the virtual reality device.

In one example of a virtual reality system, the first proximity sensor and the second proximity sensor are ultrasonic sensors configured to propagate a sound through air and to receive the sound after reflecting off the object.

In one example of a virtual reality system, the first proximity sensor and the second proximity sensor are selected from the group of proximity sensors consisting of: light detection and ranging (LIDAR) sensors, radio detection and ranging (RADAR) sensors, radio wave sensors, infrared (IR) sensors, capacitive sensors, inductive sensors, and ultrasound sensors.

In one example of a virtual reality system, the alert is selected from the group of alters consisting of: an audible alert, a visual alert, a vibration, and haptic feedback.

In one example of a virtual reality system, the interface device is selected from the group interface devices consisting of: a wearable device, a hand held controller, a glove, footwear, and a wrist device.

In one example of a virtual reality system, the first proximity sensor and the second proximity sensor are further configured to determine a velocity or acceleration of the object relative to the interface device and the headset device respectively.

In one example of a virtual reality system, the virtual reality device is employed for mixed reality settings and the alarm generates the alert in the mixed reality setting.

In one example of a virtual reality system, a first proximity sensor is mounted to the interface device or the headset device with a first angle of view and a second proximity sensor is mounted to the interface device or the headset device with a second angle of view that encompasses a different field of view compared to the first angle of view.

In one example there is provided, a method for avoiding collisions during a virtual reality experience, including

detecting an object in proximity to a virtual reality device via one or more proximity sensors associated with the virtual reality device;

determining a position and relative velocity of the object;

predicting a potential collision between a user of the virtual reality device and the object; and

generating an alarm regarding the potential collision.

In one example of a method for avoiding collisions during a virtual reality experience, the alarm is only generated for potential collisions outside of a predefined distance surrounding the virtual reality device such that body parts of the user will not trigger the alarm as the potential collision.

In one example the method for avoiding collisions during a virtual reality experience further comprises:

estimating a distance between a floor and the virtual reality device based on data regarding the orientation of the virtual reality device obtained from a gyroscope associated with the virtual reality device;

defining an outer threshold based on combining the distance between the floor and the virtual reality device with data regarding physical dimensions of a user; and

preventing the alarm from generating an alert if the potential collision is out of range of the outer threshold.

In one example of a method for avoiding collisions during a virtual reality experience, the distance between the floor and the virtual reality device dynamically changes during operation of the virtual reality device and the outer threshold is dynamically changed with the distance between the floor and the virtual reality device.

In one example of a method for avoiding collisions during a virtual reality experience, the one or more proximity sensors are ultrasonic sensors and the detecting the object propagates a sound through air and receives the sound after reflecting off the object.

In one example of a method for avoiding collisions during a virtual reality experience, the one or more proximity sensors are selected from the group of proximity sensors consisting of: light detection and ranging (LIDAR) sensors, radio detection and ranging (RADAR) sensors, radio wave sensors, infrared (IR) sensors, capacitive sensors, inductive sensors, and ultrasound sensors.

In one example of a method for avoiding collisions during a virtual reality experience, the alarm triggers an alert selected from the group of alerts consisting of: an audible alert, a visual alert, a vibration, and haptic feedback.

In one example of a method for avoiding collisions during a virtual reality experience, the generating the alarm sends the alarm to an external device.

In one example the method for avoiding collisions during a virtual reality experience further comprises:

determining a velocity or acceleration of the object relative to the virtual reality device.

In one example of a method for avoiding collisions during a virtual reality experience, the detecting the object is accomplished using a first proximity sensor with a first angle of view and a second proximity sensor with a second angle of view that encompasses a different field of view compared to the first angle of view.