Open-loop moving operation method and system of active omnidirectional treadmill

Abstract

The invention discloses an open-loop moving operation method and system of an active omnidirectional treadmill. The method comprises the following steps: determining a moving reference direction through a VR handle held by a user or an inertial sensor worn by the user; a user pushes a VR handle rocker or touches and presses a touch pad to generate a speed input value, and the speed input value is mapped into an expected walking speed; based on the reference direction and the expected speed, the target speed of the omnidirectional treadmill is calculated, and an instruction is sent to drive the treadmill to operate; the treadmill feeds back the actual speed to the calculation unit in real time, the VR picture is dynamically adjusted in the feedback speed direction, and visual synchronization is achieved. According to the method, the requirement of a high-precision position sensor can be omitted, meanwhile, the system response speed is increased, multiple reference direction input modes are supported, the free steering requirement of a user is met, the user can autonomously control the expected speed, and the risk of motion unbalance caused by algorithm delay in closed-loop control is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of omnidirectional treadmills, in particular to an open-loop moving operation method of an omnidirectional treadmill. BACKGROUND

[0002] Virtual reality technology simulates various human sensory signals such as vision, hearing, touch, movement, etc. through a computer, and provides a virtual experience that is almost indistinguishable from reality. Natural movement interaction technology is one of the important technologies in virtual reality technology that expands users' exploration of space in the virtual world. The omnidirectional motion platform based on virtual reality (VR) technology is a device that can meet the needs of users' omnidirectional movement, which enables users to walk, run, rotate, jump, squat, dodge left and right, and other actions in a limited space in virtual reality. For example, Chinese patent ZL202210149746.3 discloses a kind of active omnidirectional treadmill based on spiral roller, which is a kind of active omnidirectional treadmill with high miniaturization degree and wide home use prospect.

[0003] At present, the control of active omnidirectional treadmills is through measuring user motion information on the platform, such as waist or foot position and speed, etc. According to these motion information, feedback is made, and the user is sent back to the center of the platform to realize the natural walking of the user in any direction. In the control process, it belongs to closed-loop control. However, closed-loop control depends on the accurate measurement of user motion information by high-precision sensors, which has high sensor cost and high response speed requirement for control algorithm. SUMMARY

[0004] Technical problem: In view of the high cost of sensors and high response speed requirement of control algorithm in the closed-loop control of active omnidirectional treadmills, the present application proposes an open-loop moving operation method of active omnidirectional treadmills without the need to increase high-precision sensors, which can be adjusted by the user.

[0005] The present application also provides an open-loop moving operation system of active omnidirectional treadmills which also solves the above technical problems.

[0006] Technical solution: The present application discloses an open-loop moving operation method of active omnidirectional treadmills, comprising the following steps:

[0007] S1: The user wears a VR headset and holds a VR handle to stand on the active omnidirectional treadmill, and the calculation unit obtains the basic reference direction of the user's moving process as θ according to the user's moving reference direction acquisition method. n ;

[0008] S2: The calculation unit calculates the expected walking speed v of the user according to the user's expected speed acquisition method. t ;

[0009] S3: The computing unit calculates the speed v o of the omnidirectional treadmill based on the basic reference direction θ n and the expected walking speed v t of the user o ;

[0010] S4: The computing unit sends the speed v o instruction to the active omnidirectional treadmill, and the active omnidirectional treadmill runs according to the speed v o instruction

[0011] S5: The active omnidirectional treadmill measures the current actual running speed v c = (v cx , v cy ) and sends it to the computing unit, and the computing unit adjusts the picture in the VR headset according to the current actual running speed

[0012] Further, in step S1, the method for obtaining the user movement reference direction is to take the direction of the VR handle held by the user as the basic reference direction θ n .

[0013] Further, the method for obtaining the user movement reference direction is to wear an inertial sensor on the user's body or both feet, and measure the direction of the inertial sensor as the basic reference direction θ n .

[0014] Further, in step S2, the method for obtaining the expected speed of the user is that the user pushes or touches the rocker or touchpad of the VR handle held, and the input value of the VR handle is taken as the expected walking speed v t of the user with size and direction

[0015] Further, in step S3, the speed calculation method of the omnidirectional treadmill is that the expected walking speed of the user is given as v t = (v tx , v ty ) and the basic reference direction θ n , and the speed v o = (v ox , v oy ) that the omnidirectional treadmill should be set is calculated, wherein v ox = -sin(θ n )*v tx -cos(θ n )*v ty , v oy = cos(θ n )*v tx -sin(θ n )*v ty .

[0016] Furthermore, in step S5, the specific method for the computing unit to adjust the image in the VR head display according to the current actual running speed for interaction is as follows: when the computing unit receives the current speed v sent by the active omnidirectional treadmill c =(v cx ,v cy ), the computing unit adjusts the image in the VR headset along -αv c The direction and magnitude of , where α>0, represents the scaling factor of the velocity.

[0017] Corresponding to the above-mentioned operating method, the present invention discloses an open-loop mobile operating system for an active omnidirectional treadmill, comprising:

[0018] VR headset, worn by the user;

[0019] Active omnidirectional treadmill to support the user while standing;

[0020] The calculation unit is used to obtain the basic reference direction of the user's movement process as θ n , calculate the user's expected walking speed v t , calculate the speed v that the omnidirectional treadmill should be set to o , the speed v o The command is sent to the active omnidirectional treadmill;

[0021] Active omnidirectional treadmill by speed v o The instruction runs;

[0022] Active omnidirectional treadmill measures the current actual running speed v c =(v cx ,v cy ) is sent to the computing unit, and the computing unit adjusts the image in the VR headset according to the current actual running speed for interaction.

[0023] Furthermore, the computing unit refers to an independent host with computing capabilities, or a computing chip built into a VR headset.

[0024] Furthermore, the calculation unit uses the direction of the VR handle held by the user as the reference direction θ n .

[0025] Furthermore, an inertial sensor is included. The inertial sensor is worn on the user's body or feet. The calculation unit measures the direction of the inertial sensor as a reference direction θ n .

[0026] Furthermore, when the user pushes or touches the joystick or touchpad of the VR controller, the calculation unit uses the input value of the VR controller as the user's expected walking speed v with size and direction.t .

[0027] Furthermore, the calculation unit calculates the walking speed v expected by the user. t =(v tx ,v ty ) and the base reference direction θ n , calculate the speed v that the omnidirectional treadmill should be set to o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θ n )*v ty .

[0028] Furthermore, the computing unit receives the current speed v sent by the active omnidirectional treadmill. c =(v cx ,v cy ), the computing unit adjusts the image in the VR headset along -αv c The direction and magnitude of , where α>0, represents the scaling factor of the velocity.

[0029] Beneficial effects:

[0030] 1. The present invention collects data input from a VR handle to enable users to move in an open-loop manner on an active omnidirectional treadmill. Users can walk naturally at their intended speed without adding high-precision sensors and complex control algorithms, significantly reducing the hardware cost of the device.

[0031] 2. By installing inertial measurement units on the waist and feet, the user can look around while moving in the intended direction.

[0032] 3. Users can improve the safety of equipment operation by adjusting the speed themselves. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of Example 1 of the present invention, in which the computing unit adopts an independent host and the direction of the VR handle held by the user is used as the reference direction of the user's movement.

[0034] Figure 2 This is a schematic diagram of embodiment 2 of the present invention, in which the calculation unit adopts an independent host and obtains the user's movement reference direction through the inertial sensor installed on the user's waist.

[0035] Figure 3 The figure is an embodiment of the present application, in which the computing unit uses the computing chip built in the VR headset, and the user movement reference direction is obtained by measuring the inertial sensor installed on the user's feet.

[0036] Figure 4 The figure is a schematic diagram of the VR handle in the present application, in which the input method is different between the joystick and the touchpad. DETAILED DESCRIPTION

[0037] The present application provides an open-loop movement operation method and system of an active omnidirectional treadmill. Since the active omnidirectional treadmill belongs to the prior art, for example, the active omnidirectional treadmill disclosed in Chinese patent ZL202210149746.3, the specific structure and implementation principle of the active omnidirectional treadmill are not described in detail in the present application, and the protection mechanism of the active omnidirectional treadmill is omitted in the present application. Its main function is to provide users with speed in any direction on the platform.

[0038] Embodiment 1

[0039] As Figure 1 , the user wears a VR headset 20, holds a VR handle 21, and stands on an active omnidirectional treadmill 10. In this embodiment, an independent host 30 is used as a computing unit 50.

[0040] The computing unit 50 obtains the basic reference direction θ of the user movement process according to the method of obtaining the user movement reference direction n . In this embodiment, the specific method is as follows:

[0041] First, the computing unit 50 obtains the attitude Euler angle (θ pitch , θ roll , θ yaw ) of the VR handle 21 in the omnidirectional treadmill platform coordinate system (X-Y-Z) through the positioning system of the VR headset 20 and the VR handle 21, wherein θ pitch , θ roll , θ yaw respectively represent the pitch angle, roll angle, and heading angle of the VR handle 21; the heading angle θ yaw is used as the basic reference direction θ n , that is, θ n = θ yaw .

[0042] Combining Figure 4As shown, in this embodiment, the joystick or touchpad of at least one VR handle of the left or right hand is regarded as the user's desire to obtain the expected speed by default. In any case, the user's operation of the joystick or touchpad of the VR handle is regarded as the user's desire to obtain the expected speed. The functions of the buttons on the VR handle remain unchanged. When the user needs to set the expected speed, the user pushes or touches the joystick 22 or touchpad 23 of the VR handle 21, and the calculation unit 50 obtains the current position of the joystick 22 or touchpad 23 through the VR handle 21 as p=(p x ,p y ), thereby obtaining the user's expected walking speed v t =(v tx ,v ty )=F(p x ,p y ), where F(p x ,p y ) indicates that the position data (p x ,p y ) to the user's expected walking speed. In general, it can be (v tx ,v ty )=(kp x ,kp y ), that is, scaling by k times, which can be adjusted dynamically. When k=1, it is a one-to-one mapping relationship. In addition, F(p x ,p y ) can also introduce nonlinear mapping relationships, such as limiting maximum and minimum values, to obtain a better user experience.

[0043] When the calculation unit 50 obtains the user basic reference direction as θ n and the user's expected walking speed v t Then the speed v that the omnidirectional treadmill should be set to is calculated. o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θ n )*v ty .

[0044] The calculation unit 50 sets the speed v that the omnidirectional treadmill should be set to oThe active omnidirectional treadmill 10 receives the speed command via wireless network or Bluetooth and runs accordingly. Then the active omnidirectional treadmill 10 measures the current actual running speed v c =(v cx ,v cy ) and sends it to the computing unit 50 via wireless network or Bluetooth. Then the computing unit 50 adjusts the direction and size of the picture in the VR headset to change along -av c , where a > 0, indicating the scaling factor of the speed.

[0045] Embodiment 2

[0046] As Figure 2 , the user wears the VR headset 20 and holds the VR handle 21, and stands on the active omnidirectional treadmill 10. In this embodiment, a separate host computer 30 is used as the computing unit 50, and the user wears an inertial sensor 40 on the waist.

[0047] The computing unit 50 obtains the basic reference direction θ n of the user's movement process according to the method of obtaining the reference direction of the user's movement. In this embodiment, the specific method is:

[0048] First, the computing unit 50 obtains the attitude Euler angle (θ pitch , θ roll , θ yaw ) of the inertial sensor 40 in the omnidirectional treadmill platform coordinate system (X-Y-Z) through wireless network or Bluetooth, and uses the heading angle θ yaw as the basic reference direction θ n , that is, θ n = θ yaw .

[0049] As Figure 4 shown, the user pushes or touches the rocker 22 or touchpad 23 of the VR handle 21, and the computing unit 50 obtains the current position of the rocker 22 or touchpad 23 through the VR handle 21 as p = (p x , p y ), thereby obtaining the walking speed v t =(v tx , v ty ) = F(p x , p y ) expected by the user, where F(p x , p y ) represents a function mapping from position data (p x , p y ) to the walking speed expected by the user. Generally, it can be (v tx , v ty )=(kp x , kpy ), that is, scaling by k times, which can be adjusted dynamically. When k=1, it is a one-to-one mapping relationship. In addition, F(p x ,p y ) can also introduce nonlinear mapping relationships, such as limiting maximum and minimum values, to obtain a better user experience.

[0050] When the calculation unit 50 obtains the user basic reference direction as θ n and the user's expected walking speed v t Then the speed v that the omnidirectional treadmill should be set to is calculated. o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θ n )*v ty .

[0051] The calculation unit 50 sets the speed v that the omnidirectional treadmill should be set to o The speed is sent to the active omnidirectional treadmill 10 via wireless network or Bluetooth, and the active omnidirectional treadmill 10 runs according to the speed instruction. Then the active omnidirectional treadmill 10 measures the current actual running speed v c =(v cx ,v cy ), and also sent to the computing unit 50 via wireless network or Bluetooth, and then the computing unit 50 adjusts the image in the VR head display along -αv c The direction and magnitude of , where α>0, represents the scaling factor of the velocity.

[0052] Example 3

[0053] like Figure 3 The user wears a VR head display 20, holds a VR handle 21, and stands on the active omnidirectional treadmill 10. In this embodiment, the computing chip built into the VR head display 20 is used as the computing unit 50, and the user wears an inertial sensor 40 on each foot.

[0054] The calculation unit 50 obtains the basic reference direction θ of the user's movement process according to the method for obtaining the user's movement reference direction n In this embodiment, the specific method is:

[0055] First, the calculation unit 50 obtains the Euler angles (θ) of the two inertial sensors 40 in the omnidirectional treadmill platform coordinate system (XYZ) through wireless network or Bluetooth. pit ,θ roll ,θ yaw1 ), (θ pitch2 ,θ roll2 ,θ yaw ) Use the average value of the heading angle as the basic reference direction θ n ,Right now

[0056] Combine Figure 4 As shown, the user pushes or touches the rocker 22 or touchpad 23 of the VR handle 21, and the calculation unit 50 obtains the current position of the rocker 22 or touchpad 23 through the VR handle 21 as p=(p x ,p y ), thereby obtaining the user's expected walking speed v t =(v tx ,v ty )=F(p x ,p y ), where F(p x ,p y ) indicates that the position data (p x ,p y ) to the user's expected walking speed. In general, it can be (v tx ,v ty )=(kp x ,kp y ), that is, scaling by k times, which can be adjusted dynamically. When k=1, it is a one-to-one mapping relationship. In addition, F(p x ,p y ) can also introduce nonlinear mapping relationships, such as limiting maximum and minimum values, to obtain a better user experience.

[0057] When the calculation unit 50 obtains the user basic reference direction as θ n and the user's expected walking speed v t Then the speed v that the omnidirectional treadmill should be set to is calculated. o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θn )*v ty .

[0058] The computing unit 50 will set the speed v o to the active omnidirectional treadmill 10 via wireless network or Bluetooth, and the active omnidirectional treadmill 10 will run according to the speed instruction. Then the active omnidirectional treadmill 10 measures the current actual running speed v c = (v cx , v cy ), and also sends it to the computing unit 50 via wireless network or Bluetooth, and then the computing unit 50 adjusts the direction and size of the picture in the VR headset to change along -av c , where a > 0, indicating the scaling factor of the speed.

[0059] Figure 4 Two different types of VR handles 21 are shown, where the left one uses a joystick 22, and the right one uses a touchpad 23. When the user pushes or touches the joystick 22 or the touchpad 23, the VR handle 21 can obtain the current position of the user's push or touch through the built-in sensor. The current position is p = (p x , p y )

[0060] The above embodiments are only preferred embodiments of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and equivalent replacements can be made, and these improved and equivalent replaced technical solutions of the present application claims fall within the protection scope of the present application.

Claims

1. An open-loop movement operation method for an active omnidirectional treadmill, characterized in that: The following steps are involved: S1: The user wears a VR headset and holds a VR controller while standing on an active omnidirectional treadmill. The calculation unit obtains the basic reference direction of the user's movement process as θ according to the method for obtaining the user's movement reference direction. n ; S2: The calculation unit calculates the user's expected walking speed v according to the method for obtaining the user's expected speed t ; S3: Calculation unit based on the basic reference direction θ n and the user's expected walking speed v t According to the speed calculation method of the active omnidirectional treadmill, the speed v that the omnidirectional treadmill should be set to is calculated. o ; S4: The calculation unit converts the speed v o The command is sent to the active omnidirectional treadmill, and the active omnidirectional treadmill moves at a speed of v o The instruction runs; S5: Active omnidirectional treadmill measures the current actual running speed v c =(v cx ,v cy ) is sent to the computing unit, and the computing unit adjusts the image in the VR headset according to the current actual running speed for interaction.

2. The open-loop movement operation method of the active omnidirectional treadmill according to claim 1, characterized in that: In step S1, the method for obtaining the user's moving reference direction is to use the direction of the VR handle held by the user as the reference direction θ n .

3. The open-loop movement operation method of the active omnidirectional treadmill according to claim 1, characterized in that: The method for obtaining the user's moving reference direction is to wear an inertial sensor on the user's body or feet and measure the direction of the inertial sensor as the reference direction θ n .

4. The open-loop movement operation method of the active omnidirectional treadmill according to claim 1, characterized in that: In step S2, the method for obtaining the user's expected speed is that the user pushes or touches the joystick or touchpad of the VR controller held by the user, and the input value of the VR controller is used as the user's expected walking speed v with size and direction. t .

5. The open-loop movement operation method of an active omnidirectional treadmill according to any one of claims 1 to 4, characterized in that: In step S3, the speed calculation method of the omnidirectional treadmill is as follows: given the user's expected walking speed is v t =(v tx ,v ty ) and the base reference direction θ n , calculate the speed v that the omnidirectional treadmill should be set to o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θ n )*v ty .

6. The open-loop movement operation method of an active omnidirectional treadmill according to any one of claims 1 to 4, characterized in that: In step S5, the specific method for the calculation unit to adjust the image in the VR head display according to the current actual running speed for interaction is as follows: when the calculation unit receives the current speed v sent by the active omnidirectional treadmill c =(v cx ,v cy ), the computing unit adjusts the image in the VR headset along -αv c The direction and magnitude of , where α>0, represents the scaling factor of the velocity.

7. An open-loop mobile operating system for an active omnidirectional treadmill, characterized in that: include: VR headset, worn by the user; Active omnidirectional treadmill to support the user while standing; The calculation unit is used to obtain the basic reference direction of the user's movement process as θ n , calculate the user's expected walking speed v t , calculate the speed v that the omnidirectional treadmill should be set to o , the speed v o The command is sent to the active omnidirectional treadmill; Active omnidirectional treadmill by speed v o The instruction runs; Active omnidirectional treadmill measures the current actual running speed v c =(v cx ,v cy ) is sent to the computing unit, and the computing unit adjusts the image in the VR headset according to the current actual running speed for interaction.

8. The open-loop mobile operating system of the active omnidirectional treadmill according to claim 7, characterized in that: A computing unit refers to an independent host with computing capabilities, or a computing chip built into a VR headset.

9. The open-loop mobile operating system of the active omnidirectional treadmill according to claim 7, characterized in that: The calculation unit uses the direction of the VR handle held by the user as the reference direction θ n .

10. The open-loop mobile operating system of the active omnidirectional treadmill according to claim 7, characterized in that: It also includes an inertial sensor, which is worn on the user's body or feet. The computing unit measures the direction of the inertial sensor as a reference direction θ n .

11. The open-loop mobile operating system of the active omnidirectional treadmill according to claim 7, characterized in that: When the user pushes or touches the joystick or touchpad of the VR controller, the calculation unit uses the input value of the VR controller as the user's expected walking speed v with size and direction. t .

12. The open-loop mobile operating system of an active omnidirectional treadmill according to any one of claims 7 to 11, characterized in that: The calculation unit is given the user's expected walking speed v t =(v tx ,v ty ) and the base reference direction θ n , calculate the speed v that the omnidirectional treadmill should be set to o =(v ox ,v oy ), where v ox =-sin(θ n )*v tx -cos(θ n )*v ty , v oy =cos(θ n )*v tx -sin(θ n )*v ty .

13. The open-loop mobile operating system of an active omnidirectional treadmill according to any one of claims 7 to 11, characterized in that: The computing unit receives the current speed v sent by the active omnidirectional treadmill c =(v cx ,v cy ), the computing unit adjusts the image in the VR headset along -αv c The direction and magnitude of , where α>0, represents the scaling factor of the velocity.

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