Sliding sports simulator

Abstract

A sliding sports simulator (1), comprising: - a platform (2) comprising a means (21) for accommodating a user; - means for determining the speed, orientation, and acceleration of said platform (2); - a CDPR robot (4) comprising a plurality of cables (41) connected to the platform (2) for transmitting to said platform (2) three-dimensional translational and rotational displacements; - virtual reality goggles (5) configured to display sliding sports images to the user; - a processing means (6) in communication with the means for determining the speed, orientation, and acceleration of the platform (2), the CDPR robot (4), and the virtual reality glasses (5), the processing means (6) being configured to control the CDPR robot (4) to move the platform (2) in coordination with the images displayed by the virtual reality glasses (5), characterized in that the platform (2) comprises a rotating base (22) on which the means (21) for accommodating the user is disposed, the rotating base (22) being configured to transmit to the means (21) for accommodating the user a rotational displacement relative to the rest of the platform (2) as a function of commands from the processing means (6).

Description

Sliding sports simulator OBJECT OF THE INVENTION The present invention generally belongs to the field of virtual reality-based sports simulators. The object of the invention is a new sliding sports simulator equipped with a CDPR robot capable of emulating the movements of a sport in which the athlete controls the movements with a bar held in their hands, for example, windsurfing or kitesurfing, in a particularly precise manner. BACKGROUND OF THE INVENTION Virtual reality sports simulators have been around for some time. These simulators work by showing the user, through virtual reality headsets, images of the sport in question from the athlete's perspective. This gives the user the impression that they are actually playing the sport. One drawback of this type of simulator is that the user, despite receiving visual stimuli very similar to those experienced by an athlete actually practicing the sport, does not feel the accelerations to which a real athlete is subjected, since they are usually sitting or standing in a static position. To solve this problem, the Max Planck Institute has recently developed a simulator based on the use of a cable-driven parallel robot (hereinafter referred to as CDPR robot or Cable-Driven Parallel Robot). A CDPR robot is a specific type of parallel robot in which the end effector, in this case a platform, is suspended by several flexible cables. The length of these cables can be reduced by winding them onto reels that are automatically driven by servomotors and located in fixed positions. These are the types of robots currently used in soccer and other sports fields to move cameras that provide overhead views of the playing field. However, there can be multiple configurations in terms of the number of cables used and the location of their output pulleys relative to the element to be moved (the platform), resulting in different kinematic configurations. These robots offer numerous advantages over rigid robots, such as a lightweight structure, low inertia, the ability to move large loads over large work areas, and high speeds and accelerations. In the simulator developed by the Max Planck Institute, the user, wearing virtual reality goggles, stands on the platform. The goggles then display images of a sport or other activity involving movement, and simultaneously, the platform on which the user stands moves in coordination with the images shown through the goggles. In this way, the visual stimuli received by the user are accompanied by real sensations associated with the movements they are experiencing, such as acceleration, braking, or turning. The effect is a much more realistic sensation of the simulated activity or sport. A description of this simulator can be found, for example, on the following websites: https: / / www.cyberneum.de / CableRobotSimulator https: / / www.youtube.com / watch?v=C19pNaV4k_4 While this simulator provides much more realistic sensations than simply viewing images through virtual reality glasses with the user in a static position, it still has several drawbacks. A primary drawback is related to a limitation in the platform's rotation angle. It is known that CDPR robots cannot impart rotations to the end effector—in this case, the platform—around a vertical axis greater than approximately 20-30 degrees. This is because the cables supporting the platform could collide with each other and with the platform itself. Consequently, the Max Planck Institute's simulator cannot realistically simulate rotational movements displayed to the user through virtual reality glasses. A second drawback is the inability to give the user control over the images they are viewing. The simulator developed by the Max Planck Institute shows the user specific images accompanied by platform movements. However, the images displayed are pre-set and cannot be modified in any way. They are essentially videos, whether real or computer-generated, which are not editable. DESCRIPTION OF THE INVENTION The inventors of this application solve the aforementioned problems by means of a new simulator whose platform has a rotating base on which the user stands. This allows the user to perform unlimited rotational movements to simulate complete turns. Furthermore, the proposed simulator may include a haptic bar through which the user can interact with images, as in a video game, with the platform's movement coordinated with these images at all times. In this document, the term "gliding sports" refers to sports based on the sliding of a board (or other devices such as boats) across a surface or a sail through the air, such as surfing, windsurfing, kitesurfing, skateboarding, hang gliding, paragliding, canoeing, etc. However, it should be noted that the potential uses of the simulator of the invention are not limited to these sports. In this document, the term "inertial measurement unit" refers to an electronic device that measures and reports the velocity, orientation, and gravitational forces of an apparatus using a combination of accelerometers and gyroscopes. The inertial measurement unit operates by detecting the current rate of acceleration using one or more accelerometers and detecting changes in rotational attributes such as pitch, roll, and yaw using one or more gyroscopes. This is the element commonly used in mobile phones or video game controllers to determine their velocity, orientation, and acceleration. In the present invention, an inertial measurement unit can be used to determine and track the movement of the bar held by the user, and this can be the "controllers" of the virtual reality device, if equipped with them, or standalone inertial devices.This device is used to capture user commands through the position or change in position of the bar. As for tracking the movements of the patient support platform, this can be done through a second inertial measurement unit or, alternatively, through the encoders of the servomotors that are part of the CDPR robot's motion control system. In this document, the term "virtual reality glasses" refers to a display device worn on a user's head that displays computer-generated images on a screen very close to the eyes. Because of their proximity to the eyes, virtual reality glasses make the displayed images appear much larger than those seen on regular screens, and can even encompass the user's entire field of vision. Furthermore, since the glasses are attached to the user's head, they can track their movements. First aspect: sliding sports simulator A first aspect of the present invention is directed to a sliding sports simulator that fundamentally comprises the following elements: a platform, means for determining the speed, orientation and acceleration of the platform, a CDPR robot, virtual reality glasses, and a processing means. Each of these elements is described in more detail below. a) Platform The platform is the element moved by the CDPR robot on which the user is positioned. In principle, the platform can have any configuration as long as it is properly connected to the CDPR robot's cables and has sufficient space for the user. Specifically, the platform includes a means of accommodating a user, such as a chair mounted on the platform's rotating base. This will typically be a safety chair equipped with user restraints. Alternatively, instead of a chair, the platform could include restraints for a wheelchair. In this case, the platform will also have an access ramp. b) Means of determining the speed, orientation and acceleration of the platform To function properly, the simulator of the invention needs to know at all times the speed, orientation, and acceleration of the platform. This information can preferably be obtained in two ways. In a first preferred embodiment, the means for determining the speed, orientation, and acceleration of the platform comprise a first inertial measuring unit fixed to the platform. In a second preferred embodiment, the means for determining the speed, orientation, and acceleration of the platform comprise encoders arranged in servomotors that actuate reels to which the cables of the CDPR robot are connected. That is, in this case, the encoders of the servomotors that drive the CDPR robot itself are used. c) CDPR Robot The CDPR robot comprises a plurality of cables connected to the platform to transmit to said platform three-dimensional translational and rotational displacements. In principle, the configuration of the CDPR robot, for example, the number of cables, connection points with the platform, position of the end of each cable opposite the connection with the platform, etc., can be anything as long as it allows the platform to perform a wide variety of translational and rotational movements. d) Virtual reality glasses These are virtual reality glasses or VR glasses configured to show the user images of sliding sports. e) Processing medium The processing medium is in communication with the media to determine the speed, orientation, and acceleration of the platform, the CDPR robot, and the virtual reality glasses. In this context, it is understood that both the CDPR robot and the virtual reality headset have their own dedicated control system. The CDPR robot's control system is configured to control the state of the cables to which the platform is connected, in order to move it to a specific position or to cause it to experience a certain acceleration, speed, trajectory, or similar action. To achieve this, the CDPR robot's control system controls the rotation speed of servomotors that move the reels onto which the end of the cables opposite the one attached to the platform is wound. Meanwhile, the virtual reality headset's control system is configured to control the playback of the images displayed on the screen. Both control systems have, or are connected to, a communication medium capable of communicating with the simulator's processing system as a whole. This communication can be of any type, wired or wireless, as long as it has sufficient speed. For example, communication can be carried out using Bluetooth, Wi-Fi, Zigbee, or similar technologies. Furthermore, the processing medium can be any device with sufficient processing power and input / output capabilities to manage the operation of the simulator's components. For example, the processing medium could include a microprocessor, microcontroller, FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), ASIC (Application-Specific Integrated Circuit), PLC (Programmable Logic Controller), PAC (Process Automation Controller), or similar devices. The processing medium must have, or be connected to, a communication medium compatible with the communication medium of the CDPR robot and the virtual reality headset. The processing unit is configured to control the CDPR robot, causing it to move the platform in coordination with the images displayed by the virtual reality headset. For example, if the images show forward acceleration, such as in a windsurfing or kitesurfing simulation, due to a gust of wind in the direction of travel, the processing unit instructs the CDPR robot to accelerate the platform forward. In response, the robot's control system sends commands to the appropriate servomotors to wind or unwind the necessary cables onto their reels. The result is that, essentially simultaneously with the virtual forward acceleration shown in the images, the platform is also accelerated forward in the real world, and therefore the user sitting on it perceives both stimuli simultaneously. So far, a simulator similar to known simulators of the prior art has been described, such as the simulator developed by the Max Planck Institute. However, the simulator of the present invention differs from that in that the platform comprises a rotating base on which the user accommodation mechanism is arranged. The rotating base can thus transmit a rotational displacement relative to the rest of the platform to the user accommodation mechanism, based on commands from the processing unit. Preferably, the rotating base is configured to rotate without any limit on the angle of rotation relative to the rest of the platform. That is, the rotating base can rotate 360° or more relative to the rest of the platform in either direction of rotation. This configuration is advantageous because it resolves the drawback of the previous technology's simulator, which was its inability to display rotational displacements greater than those achievable by the CDPR robot. The rotating base has a motor that, controlled by the processing unit, causes it to rotate. Thus, when the images displayed to the user represent a rotation of, for example, 270°, the processing unit instructs the rotating base to rotate the necessary angle in the corresponding direction. This, combined with the angle rotated by the platform as a whole via the CDPR robot, achieves the total rotation of 270°. In a particularly preferred embodiment of the invention, the simulator further comprises a haptic bar equipped with at least a second inertial measurement unit configured to determine the velocity, orientation, and acceleration of said haptic bar. For example, the second inertial measurement unit may be integrated into a controller of the type used in current video game consoles, in which case one or more controllers would be rigidly attached to the haptic bar. Furthermore, in this configuration, the processing medium is in communication with said second inertial measurement unit, so that the processing medium is aware of the orientation and velocity that the user imparts to the haptic bar. Thus, the processing medium is configured to control the CDPR robot and the images displayed by the virtual reality glasses based on the velocity, orientation, and acceleration of the haptic bar. This configuration is advantageous because it allows the simulator to move beyond being static, meaning the user cannot interact with the displayed images in any way. Thanks to the haptic feedback bar, the user can interact with the images. For example, if the images show the viewpoint of a windsurfer, they can display the user's hands holding the boom. Simultaneously, in the real world, the user will be holding the haptic feedback bar. The simulator can then be programmed so that movements of the haptic feedback bar are replicated in the images as movements of the boom, with a corresponding simulation of the effect these boom movements would have on the board's behavior. Thus, if the user rotates the haptic feedback bar in a particular direction, this would be detected by the second inertial measurement unit and transmitted to the simulator's processing unit.The processing unit would generate images corresponding to the turn the board would undergo if a real athlete turned the boom in the direction the user rotated the haptic bar, and these images would be displayed to the user through virtual reality glasses. Simultaneously, the processing unit would instruct the CDPR robot to move the platform in a way that approximately replicates the inertial forces a real athlete would experience when performing that turn. The result of this entire process is that, by rotating the haptic bar, the user directly influences the images they see, which remain synchronized with the movements of the CDPR robot. In principle, the haptic bar could function with a single second inertial measurement unit rigidly attached to it. However, in a particularly preferred embodiment of the invention, the haptic bar comprises two second inertial measurement units, each attached to one end. Furthermore, as mentioned, the CDPR robot can adopt any configuration that allows the platform to perform sufficient three-dimensional displacements and rotations to simulate the forces experienced by an athlete during the simulated activity or sport. Therefore, in principle, there are no limitations regarding the number of cables, the location of the reels on which the cable ends are wound, the point of connection to the platform, etc. However, according to a preferred embodiment of the invention, the CDPR robot may comprise several posts to the upper portion of which reels driven by corresponding servomotors are attached, each cable of the CDPR robot being connected between the platform and one of said reels. More preferably, the CDPR robot may specifically comprise eight cables and four posts, wherein an upper portion of each post comprises two reels attached at different heights. In this configuration, each cable has a first end connected to the platform and a second end connected to a reel. Even more preferably, the posts are arranged in a square or rectangle, and the platform is rectangular or square, with the first ends of the two cables connected to the reels of the same post attached to the same corner of the platform. Second aspect: operating procedure of a simulator A second aspect of the present invention relates to an operating procedure for a sliding sports simulator. The simulator essentially comprises the following elements, which are similar to those described in the preceding paragraphs of this document: a) A platform comprising a means configured to accommodate a user, usually a safety seat. b) Means for determining the speed, orientation, and acceleration of the platform. As mentioned, these may include one or more first inertial measurement units, or the encoders of the CDPR robot's own servomotors may be used. c) A CDPR robot comprising a plurality of cables connected to the platform to transmit to said platform three-dimensional translational and rotational displacements. d) Virtual reality glasses configured to show the user images of sliding sports. e) A processing means in communication with the means to determine the speed, orientation and acceleration of the platform, the CDPR robot, and the virtual reality glasses, the processing means being configured to control the CDPR robot to move the platform in coordination with the images displayed by the virtual reality glasses. This operating procedure is characterized by the step of controlling, via the processing device, a rotating base of the platform on which the device configured to accommodate the user is located. This allows a rotational displacement to be transmitted to the device that accommodates the user relative to the rest of the platform. In a particularly preferred embodiment, the process further comprises the step of controlling, by means of the processing medium, the CDPR robot and the images displayed by the virtual reality glasses based on the velocity, orientation, and acceleration of a haptic bar. In this configuration, the haptic bar comprises at least a second inertial editing unit configured to determine its velocity, orientation, and acceleration, with the processing medium communicating with said second inertial measurement unit. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a schematic perspective view of a simulator according to the present invention. Figures 2A and 2B show respective top and interior perspective views of a platform according to the present invention. Fig. 3 shows a perspective view of a haptic bar according to the present invention. Figure 4 shows a schematic diagram of some of the elements that make up the simulator of the present invention PREFERRED EMBODIMENT OF THE INVENTION Fig. 1 shows an overview of the system (1) of the present invention, where the different elements that make it up can be seen. The user is seated on a user-accommodating device (21), in this case a seat, which is arranged on a platform (2). As shown in more detail in Figs. 2A and 2B, the platform (2) comprises a square lower plate (23) with a handrail (24) running along its perimeter, except for an area where the entrance is located. A distinct circular plate occupies a central portion of the lower plate (23), thus forming the base (22) of the platform (22) on which the seat is placed. The underside view of the platform (2) in Fig. 2B shows part of the drive mechanism that allows the base (22) to rotate relative to the lower plate (23). The rotational position of the rotating base (22) relative to the rest of the platform (2) can be determined by suitable means, such as an encoder in the motor that drives the rotation, or similar devices. Although not shown in the figures, the platform (2) has at least one inertial measurement unit (3). As mentioned earlier in this document, the inertial measurement unit (3) has the necessary accelerometers and gyroscopes to determine the velocity, orientation, and acceleration of the platform (2) at any given time. The first inertial measurement unit (3) can be fixed to any point on the platform (2) that is not attached to the rotating base (22), provided that it allows these parameters to be determined with sufficient accuracy. Alternatively, information about the position, velocity, and acceleration of the platform could be obtained from the encoders located on the servomotors of the CDPR robot (4) that drive the reels to which the cables (41) are attached. Also not shown in the figures, the platform (2) may have an access ramp to allow wheelchair entry. It may also have anchoring means arranged on the rotating base (22) to securely attach the wheelchair. Furthermore, although in this example the platform (2) is square, it would be possible to implement platforms of any other shape as long as they are large enough to accommodate a rotating base (22) on which a wheelchair for the user can fit. Returning to Fig. 1, it can be seen how the seat is fixed to the center of the base (22). The platform (2) constitutes the end effector of a CDPR robot (4) formed by a plurality of cables (41) connected to posts (42). In particular, in this example, the CDPR robot (4) comprises four posts (42) arranged in a square. Each post (42) comprises two servomotors that drive corresponding reels. A first servomotor / reel assembly is located at a first height of the post (42), and a second servomotor / reel assembly is located at a second height of the post (42), both assemblies being located in the upper portion of the post (42). The cable (41) connected to the first servo motor / reel assembly has its opposite end connected to a corner of the platform (2), and the cable connected to the second servo motor / reel assembly of the same post (42) also has its opposite end connected to the same corner of the platform (2).The CDPR robot (4) thus comprises four pairs of cables (41), each pair of cables (41) being arranged between a corner of the platform (2) and the two servomotor / reel assemblies of a post (42). A dedicated control means for the CDPR robot (4) commands the actuation of the servomotors to move the platform (2) in the desired manner according to the received command. In this example, the control means for the CDPR robot (4) also has a communication means that allows it to communicate with an external entity to receive commands. Figure 1 also shows that the user is wearing virtual reality glasses (5), or VR glasses. As is well known, these glasses (5) have screens located very close to the eyes and a dedicated control unit that controls the images (100) displayed to the user. The glasses' control unit (5) also has a communication channel configured to communicate with an external entity. This external entity can transmit the images (100) to be reproduced to the glasses (5), in which case the glasses' control unit (5) would only perform the reproduction. Alternatively, the external entity can transmit certain requirements for the images (100) to be reproduced, in which case the glasses' control unit would have the necessary elements to generate the images (100). The system (1) shown in Fig. 1 also includes a haptic bar (7) that the user is holding with both hands. The haptic bar (7), shown in more detail in Fig. 3, has two second inertial measurement units (71), one attached to each of its ends. This allows for the precise determination of the bar's velocity, orientation, and acceleration. The system (1) of the invention also includes a processing means (6). The processing means (6) is connected to the various elements mentioned above according to the scheme shown in Fig. 3. In particular, the processing means (6) is connected to the control means of the CDPR robot (4), the virtual reality goggles (5), the drive motor of the rotating base (22), and the first (3) and second (71) inertial measurement units. This connection can be of any suitable type, whether wired, wireless, or a combination thereof, depending on each particular element. Thanks to this configuration, the processing unit (6) can instruct the virtual reality goggles (5) to display specific images (100) to the user from the perspective of a windsurfer. In these images (100), the boom will be in front of the user and will be represented in the real world by the haptic bar (7), which the user will grip with both hands in essentially the same position shown in the images (100). The processing unit (6) will instruct the CDPR robot (4) to move the platform (2) in coordination with the images (100) displayed through the goggles (5). When providing the command to the CDPR robot (4), the processing unit (6) can take into account the speed, orientation, and acceleration of the platform (2) provided by the first inertial measurement unit (3) attached to the platform (2).If the images (100) require it, the processing medium (6) may order the rotation of the rotating base (22), taking into account the information provided by the first inertial measuring unit (3) attached to the rotating base (22). Additionally, the processing unit (6) is connected to the second inertial measurement units (71) attached to the haptic bar (7). These second inertial measurement units (71) provide information about the velocity, orientation, and acceleration that the user imparts to the haptic bar (7). Thus, when the user moves the haptic bar (7) to elicit a specific behavior of the windsurf board in the images (100), this is detected by the processing unit (6). In response, the processing unit (6) generates images corresponding to the behavior the windsurf board would exhibit in the virtual world if the boom were moved in the same way as the haptic bar (7). These images (100) are sent to the glasses (5) for display to the user. Simultaneously, the processing unit (6) calculates the commands to be transmitted to the robot (CDPR) and the rotating base (22) to subject the user to a displacement that emulates the inertia they would experience if moving with the speed, orientation, and acceleration shown in the images (100). To do this, it may take into account the information provided by the first (3) and second (71) inertial measurement units. Once determined, it sends the commands to the motor that rotates the platform (22) and to the servomotors that move the reels that wind / unwind the cables (42) of the CDPR robot (4). The result of this process is that the user can, using the haptic bar (7), control the experience displayed through the images (100) of the VR glasses (5). This visual experience is enhanced by movements coordinated with the images of the seat where the user is seated, including movement of the platform (2) by the robot (CDPR) and rotation of the rotating base (22). Furthermore, the rotating base (22) will allow for the simulation of full rotations of more than 20°-30°, impossible to emulate with simulators of the previous technique.

Claims

1. A sliding sports simulator (1), comprising: - a platform (2) comprising a means (21) for accommodating a user; - means for determining the speed, orientation, and acceleration of said platform (2); - a CDPR robot (4) comprising a plurality of cables (41) connected to the platform (2) for transmitting to said platform (2) three-dimensional translational and rotational displacements; - virtual reality goggles (5) configured to display sliding sports images to the user; - a processing means (6) in communication with the means for determining the speed, orientation, and acceleration of the platform (2), the CDPR robot (4), and the virtual reality goggles (5), the processing means (6) being configured to control the CDPR robot (4) to move the platform (2) in coordination with the images displayed by the virtual reality goggles (5),characterized in that the platform (2) comprises a rotating base (22) on which the means (21) for accommodating the user is disposed, the rotating base (22) being configured to transmit to the means (21) for accommodating the user a rotational displacement relative to the rest of the platform (2) as a function of commands from the processing means (6).

2. Simulator (1) according to claim 1, wherein the rotating base (22) is configured to rotate without a limit on the angle of rotation relative to the rest of the platform (2).

3. Simulator (1) according to any of claims 1-2, wherein the means for determining the velocity, orientation, and acceleration of the platform (2) comprise a first inertial measurement unit (3) fixed to the platform (2).

4. Simulator (1) according to any of claims 1-2, wherein the means for determining the velocity,The orientation and acceleration of the platform (2) comprise encoders arranged in servomotors that actuate reels to which the cables (41) of the CDPR robot (4) are connected.

5. Simulator (1) according to any of the preceding claims, further comprising a haptic bar (7) provided with at least a second inertial measurement unit (71) configured to determine the velocity, orientation, and acceleration of said haptic bar (7), the processing means (6) being in communication with said second inertial measurement unit (71), such that said processing means (6) is configured to control the CDPR robot (4) and the images displayed by the virtual reality glasses (5) based on the velocity, orientation, and acceleration of the haptic bar (7).

6. Simulator (1) according to claim 5,wherein the haptic bar (7) comprises two second inertial measurement units (71), each fixed to one end.

7. Simulator (1) according to any of the preceding claims, wherein the CDPR robot (4) comprises several posts (42) to the upper portion of which reels driven by corresponding servomotors are fixed, each cable (41) of the CDPR robot (4) being connected between the platform (2) and one of said reels.

8. Simulator (1) according to claim 7, wherein the CDPR robot (4) comprises eight cables (41) and four posts (42), wherein an upper portion of each post (42) comprises two reels fixed at different heights, each cable (41) having a first end connected to the platform (2) and a second end connected to a reel.

9. Simulator (1) according to claim 8, wherein the posts (42) are arranged in a square or rectangle and wherein the platform (2) is rectangular or square,the first ends of the two cables (41) being connected to the reels of the same post (42) fixed to the same corner of the platform (2).

10. Simulator (1) according to any of the preceding claims, wherein the means (21) configured to accommodate a user is a chair fixed on the rotating base (22) of the platform (2).