EP3577540A1

EP3577540A1 - Analysis device for determining the length of a detection period contributing to a latency time in an immersive virtual reality system

Info

Publication number: EP3577540A1
Application number: EP18703077.0A
Authority: EP
Inventors: Matthieu MIKA; Christophe MION
Original assignee: PSA Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2017-02-01
Filing date: 2018-01-25
Publication date: 2019-12-11
Also published as: FR3062489B1; CN110268372A; US20190377427A1; FR3062489A1; WO2018142043A1

Abstract

The invention relates to a device (DA) performing analyses in an immersive virtual reality system, comprising a target (CD) secured to an object (O) that can move in a space (EP), and detection means (MD) for detecting the current position of said target (CD) in said space (EP) and delivering a first signal representing said current position. Said device (DA) comprises a sensor (CC) for generating a second signal when the object (O) reaches a known position in the space (EP), and analysis means (MA) that are coupled to the sensor (CC) and detection means (MD) and are used to determine a first time when a first signal representing said known detected position is received, and a second time when said second signal is received, and then to detemine a temporal distance between the determined first and second receiving times.

Description

ANALYSIS DEVICE FOR DETERMINING A DETECTION DELAY CONTRIBUTING TO LATENCY TIME IN AN IMMERSIVE SYSTEM OF VIRTUAL REALITY

The invention relates to immersive virtual reality systems.

In some areas, such as vehicles, possibly of the automotive type, virtual reality immersive systems are used to immerse a user in a virtual environment. This immersion may be intended, for example, to teach a user to evolve in a particular environment or to use objects or functions present in a particular environment, or to analyze the behavior of a user in a particular environment, or still observe a particular environment depending on the position of a user in relation to the latter.

Such immersive systems (virtual reality) include:

at least one target capable of being secured to a user (or sometimes an object) able to move in a predefined space,

detection means able to detect the current position of this target in this predefined space and to deliver a signal representative of this current position,

at least one display means responsible for displaying, on at least one screen, installed in the predefined space, images intended for this screen, and

at least one computer responsible for defining in real time for each associated screen three-dimensional (possibly stereoscopic) images of a chosen environment, according to the current position of the / each target and the position of the associated screen in the predefined space.

In such an immersive system, there is generally a time difference or delay between the moment when a user changes position and the moment when this user sees the image resulting from his change of position on each screen. This time difference or delay, usually called the latency time, results not only from the processing time of signals and data and the transmission time of signals, data and images, but also from the graphical rendering time of computers and the time difference. between the moment when the user is placed in a new position and the moment when the detection means detect the target (and therefore the user) in this new position.

Generally, the longer this latency time, the more the user is embarrassed and may experience nausea, vertigo or loss of balance. It is therefore important to find solutions to reduce it to a value that is not inconvenient for the user (that is to say, that tends to zero).

However, before finding such solutions, it is necessary to have previously determined the main contributions to the latency, and in particular the time difference between the moment when the user is placed in a new position and the moment when the detection means detect the target in this new position. However, today there is no known solution for determining the latter time difference.

The invention is therefore particularly intended to allow the determination of this last time difference.

It proposes for this purpose an analysis device for performing analyzes in an immersive virtual reality system comprising at least one target adapted to be secured to an object capable of moving in a space and detecting means capable of detecting the current position of this target in this space and to deliver a first signal representative of this current position.

This analysis device is characterized by the fact that it comprises:

- the object equipped with each target,

a sensor capable of generating a second signal when the object reaches a known position in this space, and

analysis means coupled to the sensor and detection means and able to determine a first instant of reception of a first signal, representative of the detected known position, and a second instant of reception of the second signal, then to determine a time difference between these first and second reception instants determined.

It is thus possible to quantify the time difference between the actual arrival in a new position and the detection of this arrival, which contributes significantly to the latency of the immersive system.

The analysis device according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

it may comprise a rail on which the object is able to move and which is adapted to be placed in the space so that the object can move to the known position;

it can comprise a support on which the rail is fixedly fixed;

The rail can be secured to the support so as to be inclined at a predefined acute angle with respect to a horizontal plane of the space, and thus allow an automatic gravitational displacement of the object with respect to the rail between a position of departure and at least the known position;

it may comprise electromagnetic means fixedly installed on the rail, and able to immobilize the object in the starting position when they are placed in a first state of attraction, and to release the object, so that it can move to the known position, when placed in a second non-attractive state; The electromagnetic means may have an operation that is controllable remotely;

the object may be provided with an electric motor capable of inducing its movement during operation;

the electric motor can have an operation that is controllable remotely;

the sensor may be able to be placed in the vicinity of the known position and to generate the second signal when the object contacts it.

The invention also proposes an immersive system of reality virtual device comprising at least one target adapted to be secured to an object adapted to move in a space, detection means adapted to detect the current position of the target in this space and to deliver a first signal representative of this position in progress , and an analysis device of the type of that presented above.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawings, in which:

FIG. 1 diagrammatically and functionally illustrates part of an immersive virtual reality system coupled to an exemplary embodiment of an analysis device according to the invention in which the object to be detected is placed in a starting position, and

FIG. 2 diagrammatically and functionally illustrates the part of the immersive virtual reality system of FIG. 1 with the object to be detected of the analysis device placed in a known (final) position.

The object of the invention is notably to propose a DA analysis device intended to perform analyzes in an immersive system of virtual reality SI in order to determine a time difference ect participating in the latency time of the latter (SI).

In what follows, it is considered, by way of nonlimiting example, that the virtual reality immersive system SI is intended to immerse a user in a virtual environment representative of at least a part of a vehicle, possibly of the automotive type. (such as a car). But the invention is not limited to this type of virtual environment. It concerns indeed any type of virtual environment.

FIGS. 1 and 2 show schematically a small part of an immersive (virtual reality) system SI associated with a predefined space EP in which at least a partial embodiment of an analysis device DA according to the invention.

This small part here only comprises a PC target gate, here secured to an object O, mobile and part of the analysis device DA, and detection means MD capable of detecting the current position of the CD targets of the target gate PC in this predefined EP space and to deliver a first signal s1 representative of this current position. It will be noted that the target gate PC here comprises four CD targets whose positions must be determined at each measurement instant by the detection means MD in order to deduce therefrom at each instant of measurement the current position of the object O. But it can include any number of CD targets, as long as this number is at least one (1).

For example, the detection means MD here comprise two cameras each associated with an emitter of infrared photons and capable of filming in the infrared. Each transmitter emits an infrared beam that will be reflected on the targets (or spheres) CD. Each camera records images of the photons reflected on the targets (or spheres) CD, and sends each recorded image to an image analysis computer which will deduce the position in the space of the target target PC at the instant considered. . But the MD detection means could include more than two cameras.

It should be remembered that in addition to these detection means MD and this target target PC, an immersive (virtual reality) system SI also comprises at least one computer, and at least one display means. The target PC gate is intended to equip a user (or sometimes an object) that can move in the predefined EP space.

Each display means is responsible for displaying on at least one screen, installed in the predefined space EP, images that are intended for this screen. It should be noted that each display means may comprise a screen and at least one projector, or a screen and an LCD-type slab with its associated electronic control means, for example.

The number of screens is generally between one and five. Each screen is installed in the predefined EP space. At least one computer is responsible for defining, in real time, three-dimensional (possibly stereoscopic) images of the chosen environment for at least one screen associated with it, according to the current position of the CD targets of the target gate PC and the position of this associated screen in the predefined EP space. In the presence of a projector (s), each projector is responsible for projecting on the associated screen three-dimensional images determined by the associated computer and intended for this screen.

As illustrated not only in FIGS. 1 and 2, an analysis device DA according to the invention comprises, in addition to the object O, a sensor CC and analysis means MA.

The object O is mobile so that it can move in the (predefined) space EP. In addition, as indicated above, it must be equipped with at least one CD target, possibly forming part of a target PC gate (as in the non-limiting example illustrated in Figures 1 and 2).

The DC sensor is capable of generating a second signal s2 when the object O reaches a known position p2 in the space EP.

This DC sensor can, for example and as illustrated without limitation in Figures 1 and 2, be adapted to be placed in the vicinity of the known position p2 and generate the second signal s2 when the object O contacts. For this purpose, it may, for example, be of piezoelectric or capacitive or inductive or mechanical type. But in an alternative embodiment the detection could be done without contact (and therefore at a distance), for example by interrupting a light beam passing through the known position p2.

The analysis means MA are coupled to the DC sensor and the detection means MD. They are able to determine a first instant of reception of a first signal s1 which is representative of the known position p2 detected, and a second instant i2 of reception of the second signal s2 (generated by the sensor CC), then to determine a time difference ect between these first it and second i2 instants of reception determined (ie ect = i2 - il).

It will be understood that the known position p2 serves as a reference position with respect to which the analysis means MA determine the time difference ect between the instant i2 where the object O (which materializes a user moving in the space EP ) finds itself placed in a "new position" (here p2) and the instant when the detection means MD detect the target (s) CD (and therefore the object O) in this new position (here p2) . It is recalled that this time difference ect is particularly useful to know because it contributes significantly to the latency of the immersive system SI, which we want to reduce elsewhere. For example, when the analysis means MA receives at a time a first signal s1 which represents the known position p2 detected, they record this instant as the first moment it, and when they receive at a moment a second signal s2, they record this moment as the second moment i2.

In the example shown non-limitatively in FIGS. 1 and 2, the analysis means MA are part of a computer OR which is coupled (directly or indirectly) to the sensor CC and to the detection means MD of the immersive system SI. But this is not obligatory. Indeed, they could constitute electronic equipment (for example comprising an oscilloscope and an electronic signal analysis circuit) coupled (directly or indirectly) to the DC sensor and the detection means MD of the immersive system SI. Therefore, these analysis means MA can be made in the form of software modules (or computer (or "software")), or a combination of electronic circuits (or "hardware") and software modules.

Moving the object O can be done in different ways.

Thus, the analysis device DA may, for example, comprise a rail R on which is able to move the object O and which is adapted to be placed in the space EP so that the object O can move to the known position p2. In this case the displacement of the object O is constrained. Note that this rail R may be a single axis, possibly of circular section but not necessarily.

For example, and as shown in non-limiting manner in FIGS. 1 and 2, the analysis device DA may also comprise a support SR on which the rail R. is fixedly secured.

Such a support SR may, for example, be intended to be placed on the ground in the EP space. It can therefore allow placement of the rail R in a position parallel to the ground or inclined at an acute angle predefined with respect to the ground and therefore with respect to a horizontal plane of the space EP (as illustrated in non-limiting manner in FIGS. 2).

In the first alternative (parallel), for the object O to move from a starting position to the known position p2, it must either receive a initial impulse by a person, or be provided with an electric motor preferably having remotely controllable operation (for example by wave).

In the second alternative (inclination), the displacement of the object O with respect to the rail R can be done automatically by gravitation between a starting position p1 (illustrated in FIG. 1) and at least the known position p2 (illustrated in FIG. Figure 2). In other words, the displacement results from the fall of the object O along the rail R (along the arrow F1 of FIG. 1).

Note that in the example shown non-limitatively in Figures 1 and 2, the angle of inclination of the rail R relative to the ground (here horizontal) is equal to 90 °. This makes it possible to use a simple SR carrier such as a tripod, for example. But this angle could be less than 90 °, and for example equal to 45 ° or 60 °.

It will also be noted, as illustrated without limitation in FIGS. 1 and 2, that in the second alternative (inclination), the analysis device DA may comprise electromagnetic means MEL fixedly installed on the rail R in the vicinity of the starting position p1. . These electromagnetic means MEL are able, on the one hand, to immobilize the object O in its starting position p1 when they are placed in a first state of attraction, and, on the other hand, to release the object O so that it can move to the known position p2 when placed in a second non-attractive state. These electromagnetic means MEL can, for example, be arranged in the form of an electromagnet which is attractive when it is supplied with current and not attractive when it is not supplied with current. Note that if the electromagnet is sufficiently powerful, it can also be used, when supplied with power, to raise the object O automatically from the known position p2 to its starting position p1.

Such electromagnetic means MEL may, for example, have an operation that is controllable remotely, possibly by wave. This control can be done via a computer coupled to the electromagnetic means MEL, and which is optionally that (OR) which can include the MA analysis means, or via a remote control. it allows a user to trigger the fall of the object O remotely without hindering the further detection of its fall by the detection means MD.

Note that in the example shown non-limitatively in Figures 1 and 2, the DC sensor is fixedly secured to the rail R just below the known position p2 because the DC sensor provides a contact detection.

It will also be noted that the displacement of the object O is not necessarily constrained, for example because of its attachment to a rail R. Indeed, in an alternative embodiment, it is possible to envisage that the object O be arranged in such a way that to roll on the floor of the EP space. For example, it may comprise wheels which are possibly rotated by an electric motor. In the absence of an electric motor, the object O moves from a starting position to the known position p2 by means of an initial pulse supplied by a person. In the presence of an electric motor, the operation of the latter induces the displacement of the object O from a starting position to the known position p2. This operation is then preferably remotely controllable (possibly by waves). This control can be done via a computer coupled to the object O, and which is optionally that (OR) which can comprise the analysis means MA, or via a remote control.

The object O may have a large number of arrangements, depending in particular on the way in which it must move. For example, it may be made in the form of a part (possibly metal) of parallelepipedal general shape, either with a groove or coupling means adapted (s) to its movement along a R rail, either with wheels. The movements could also be done on air cushion, for example.

Claims

1. Analysis device (DA) for an immersive virtual reality system (SI) comprising at least one target (CD) adapted to be secured to an object (O) able to move in a space (EP) and detection means (MD) capable of detecting the current position of said target (CD) in said space (EP) and delivering a first signal representative of this current position, said device comprising i) said object (O) equipped with said target ( CD), ii) a sensor (CC) capable of generating a second signal when said object (O) reaches a known position in said space (EP), and iii) analysis means (MA) coupled to said sensor (CC). ) and detection means (MD) and adapted to determine a first instant of reception of a first signal, representative of said detected known position, and a second instant of reception of said second signal, then to determine a time difference between said first and second instants of reception determined s, characterized in that it comprises a rail (R) on which is able to move said object (O) and adapted to be placed in said space (EP) so that said object (O) can move up to at said known position.

2. Device according to claim 1, characterized in that it comprises a support (SR) on which is fixedly secured said rail (R).

3. Device according to claim 2, characterized in that said rail (R) is secured to said support (SR) so as to be inclined at a predefined acute angle with respect to a horizontal plane of said space (EP), and thus allow an automatic gravitational displacement of said object (O) with respect to said rail (R) between a starting position and at least said known position.

4. Device according to claim 3, characterized in that it comprises electromagnetic means (MEL) fixedly installed on said rail (R), and own i) to immobilize said object (O) in said starting position when they are placed in a first state of attraction, and ii) to release said object (O), so that it can move to said known position, when placed in a second non-attractive state.

5. Device according to claim 4, characterized in that said Electromagnetic means (MEL) have remotely controllable operation.

6. Device according to one of claims 1 to 2, characterized in that said object (O) is provided with an electric motor adapted to induce its displacement when operating.

7. Device according to claim 6, characterized in that said electric motor has a remotely controllable operation.

8. Device according to one of claims 1 to 7, characterized in that said sensor (CC) is adapted to be placed in the vicinity of said known position and to generate said second signal when said object (O) contacts.

9. Immersive virtual reality system (SI) comprising at least one target (CD) adapted to be secured to an object (O) able to move in a space (EP) and detection means (MD) capable of detecting the current position of said target (CD) in said space (EP) and to deliver a first signal representative of this current position, characterized in that it further comprises an analysis device (DA) according to one of preceding claims.