KR100887630B1 - Travel System using Force Sensing Resistors in Immersive Virtual Environments - Google Patents

Abstract

The present invention proposes a movement system that intuitively and effectively determines movement speed and direction using two FSR sensors in an immersive virtual environment. The moving system in the immersive virtual environment using the FSR sensor of the present invention is a flexible type of the first pressure sensor and the second pressure sensor, and the analogue having information about the pressed order and pressure of the first and second pressure sensors And a control unit having an A / D converter for converting the signal into digital data. According to the present invention, it is possible to easily control movement with one finger without using a mouse or a joystick in a virtual environment, and to reduce the overall system size, thereby improving portability.

Virtual environment, navigation, movement, pressure sensor, FSR, speed, direction, control

Description

Travel System using Force Sensing Resistors in Immersive Virtual Environments

1 is a block diagram of a mobile system in a virtual environment according to an embodiment of the present invention.

2 is a perspective view of the sensor unit shown in FIG.

3 is an exploded perspective view showing the FSR sensor shown in FIG.

4 is a flow chart for explaining the control unit shown in FIG.

<Description of Symbols for Main Parts of Drawings>

10: sensor unit

11: first FSR sensor

12: second FSR sensor

20: control unit

22: A / D converter

30: power

40: server

42: head mounted display (HMD)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to navigation technology in an immersive virtual environment, and more particularly, to a moving system in an immersive virtual environment that uses two flexible pressure sensors to determine a moving speed and direction.

The two main tasks of participants in an immersive virtual environment are the manipulation and navigation of objects. Navigation is performed in two stages, one of which is to manipulate physical devices for navigation to change the movement in the virtual environment, and the other is to create spatial knowledge of the virtual environment for the first time. This is a recognition step that uses a prior knowledge of spatial knowledge of the virtual environment to perform wayfinding. In general, a step of changing a movement in a virtual environment by manipulating a physical device is also referred to as locomotion.

General travel in virtual environments is one of the important and basic interaction techniques required in most virtual environments. There are a few common ways to control the speed of movement in a virtual environment.

First, there is a method of controlling speed by using discrete data obtained by obtaining discrete data through the number of button presses or gears. This method is widely used not only for virtual reality but also for general desktop computer environments.

Secondly, as a speed control method using time, there is a method of applying a constant acceleration to the speed according to time and increasing and decreasing the speed at a time interval while pressing and releasing a button. This method is configured to allow the user to control the speed by setting a time interval using a device such as a button.

Third, as a speed control method through a range, there is a method of dividing a range into a certain area and applying different accelerations to each range. This method can use a device that can have a range, such as a dial or a slider, and can have a variety of speed changes than the speed control method using the aforementioned time.

Fourth, as a speed control method according to the degree of force, there is a method in which a user directly applies a force to the pressure sensor to control the desired degree of moving speed. This method is more direct and natural than other control methods.

In the above-described control method of moving speed using force, the strength of the force applied to the pressure sensor is obtained in the form of an analog signal through the pressure sensor and then converted into a digital signal for use in a virtual environment. As pressure sensors, sensors using tactile rubber, sensors using piezo films, and force sensing resistors (FSR) sensors are mainly used.

An example of a conventional method of controlling the moving speed by using a force is a mouse or a joy stick. In a mouse or joystick, a single FSR sensor is installed, and in a virtual environment according to the pressed pressure of the FSR sensor. It operates so that the speed change of. Meanwhile, the head mounted display (HMD) used in the virtual reality system is an output device of a human head type, which displays an independent image on each of the left and right sides of the installed glasses so that the image can be seen in three dimensions. It works.

Considering a virtual environment using a mouse or a joystick with the above-described HMD, the above-described virtual environment may require a separate device for supporting or fixing the mouse or the joystick in order to operate the mouse or the joystick, and at least one of the users. The hand is constrained to be used almost statically to manipulate the mouse or joystick. In addition, a mouse or joystick has a disadvantage in that it is inconvenient to carry, carry, and operate because it is relatively large compared to the size of a hand.

An object of the present invention is to provide a moving system in a virtual environment that can easily control the moving speed and direction in a virtual environment using two flexible pressure sensors without using a mouse or a joystick.

According to a preferred aspect of the present invention to achieve the above object, a first pressure sensor and a second pressure sensor of the flexible type; And a control unit having an A / D converter for converting an analog signal having information about the pressed order and pressure of the first and second pressure sensors into digital data. have.

Here, the first and second pressure sensors may be FSR sensors whose resistance decreases when the force applied to the active surface of the sensor increases.

In addition, the first and second FSR sensors corresponding to the first and second pressure sensors may be disposed adjacent to each other in a line.

In addition, each of the first and second FSR sensors may include an upper flexible substrate on which a semiconductor is printed on an active region, and a lower flexible substrate on which a pair of electrodes are printed on another active region facing the active region. And a spacer bonded to the upper flexible substrate and the lower flexible substrate and having openings corresponding to the active regions.

The A / D converter may output the degree of pressure by converting the input analog signal into digital data of 128 steps.

In addition, when the control unit divides the degree of pressure in 128 steps, it may be determined that the pressure is 50 or more.

The control unit may operate by dividing the output of the A / D converter by two to make the most significant bit empty.

Further, the control unit outputs 1 to the most significant bit when the first pressure sensor is pressed first and the second pressure sensor is pressed later, and 0 when the first pressure sensor is pressed first and the second pressure sensor is pressed later. Can be configured to output

The control unit may transmit the digital data to at least one of a server and an output device of the virtual environment through an RS-232 protocol.

In addition, the RS-232 protocol may include the 8-bit digital data transmission type as an unsigned char type, the most significant bit of the 8 bits may contain the direction information, and the remaining lower 7 bits may indicate a speed. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are provided to fully understand the present invention for those skilled in the art.

1 is a block diagram illustrating a mobile system in a virtual environment according to an embodiment of the present invention.

Referring to FIG. 1, the mobile system in the virtual environment of the present invention virtualizes the output of the sensor unit 10 and the sensor unit 10 including two flexible pressure sensors 12 and 14 as input units. Supplying power to the control unit 20 including the A / D (analog / digital) converting unit 22 for converting the data into an environment that can be used in the environment, and the sensor unit 10 and the control unit 20 described above. It consists of a power unit (power) 30.

The sensor unit 10 has a first pressure sensor 12 and a second pressure sensor having a high resistance value, for example, millions of kPa or more, when the electric resistance value is reduced to 5 kPa according to the pressure applied to the surface. 14) in a row, and receives information about the pressure and the moving direction of the user's finger through the first and second pressure sensors 12 and 14. As the first and second pressure sensors 12 and 14, various conventional pressure sensors may be used. However, the pressure sensor used has an elastic surface and a flexible type of pressure whose resistance changes when a pressure is applied to the surface. It is preferably a sensor, and more particularly a force sensing resistor (FSR) sensor.

The control unit 20 receives the output value of the sensor unit 10 and analyzes the pressure and the moving direction of the user's finger through the A / D converter 22 to find the moving direction and the speed in the virtual environment, and the moving direction and The digital data having the speed information is transmitted to the server 40 by serial communication. Here, the moving direction may be, for example, the forward direction or the first direction when the user moves the finger down from the top, and the backward direction or the second direction when the user raises the finger from the bottom up. The movement speed may be divided into 7 bits or 128 steps using the A / D converter 22. As the control unit 20, a microcontroller such as ATMEGA128 of ATMEL Corp. may be used. In this case, digital data may be transmitted to the server 40 or the output device 42 of the virtual environment at 37600 bps.

As the power unit 30, KA7805, manufactured by FAIRCHILD SEMICONDUCTOR, can be used. In this case, the positive voltage regulator of 3-terminal 1A can supply the power of the system at 5V 1A stably.

According to the configuration of the present invention described above, it is possible to intuitively and effectively determine the moving direction and the moving speed in the virtual environment based on the pressed order of the sensors and the degree of pressure using two FSR sensors installed in a line.

FIG. 2 is a perspective view showing the sensor unit shown in FIG. 1, and FIG. 3 is an exploded perspective view showing the FSR sensor shown in FIG. 2.

Referring to FIG. 2, in the present embodiment, the first FSR sensor 12 and the second FSR sensor 14 of the sensor unit 10 are disposed adjacent to each other in a line. Here, the adjacently arranged lines may be arranged in a first direction or in a second direction opposite to the first direction with respect to the two FSR sensors 12 and 14 only by the user releasing, bending, or extending one finger. It means that it is arranged to apply pressure.

According to the present invention, by arranging the two FSR sensors 12 and 14 in a line, the user wants to move by applying a force to the two FSR sensors 12 and 14 while moving a finger in the Xa direction or the Xb direction on the Xa-Xb straight line. You can enter the direction and speed.

The aforementioned FSR sensors 12, 14 are polymer film devices in which the resistance decreases as the force applied to the surface of the active area of the sensor increases. When a user applies a force to the FSR sensors 12 and 14, which are pressure sensors, a resistance is formed in the sensor which is inversely proportional to the magnitude of the force. Accordingly, the voltages applied across the fixed resistor R connected to the electrodes 18a and 18b of the two FSR sensors 12 and 14 generate voltages Va and Vb inversely proportional to the resistances. (Va, Vb) is converted into digital data by the A / D converter and transmitted to the input of the virtual environment.

Each of the first and second FSR sensors 12 and 14 may include an upper flexible substrate 15 having semiconductors 16 printed on two active regions separated from each other, and two active regions, respectively, as shown in FIG. 3. The lower flexible substrate 17 on which the pair of interdigitated electrodes 18a and 18b are printed, and the two openings joining the upper flexible substrate 15 and the lower flexible substrate 17 to correspond to the two active regions. And a spacer 19 having a portion 19a. In FIG. 3, the upper flexible substrate 15 is overturned by 180 degrees when bonded to the lower flexible substrate 17 so that the semiconductor 16 is bonded to the lower flexible substrate 17.

On the other hand, the FSR sensors 12 and 14 described above have an advantage of low electrical attractiveness and low price when compared to tactile rubber, which is a kind of pressure measuring sensor. In addition, the FSR sensors 12 and 14 have an advantage that they are much less affected by vibration and heat as compared to piezo films which are widely used as pressure measuring sensors. Therefore, in this embodiment, the direction and speed of movement in the virtual environment can be effectively obtained using the FSR sensor.

4 is a flow chart for explaining the control unit shown in FIG.

As shown in FIG. 4, the control unit receives an analog signal having information about a moving direction and a speed from the sensor unit, converts the received signal into digital data for use in a virtual environment, and outputs the converted signal.

To this end, the control unit is first initialized when the system is driven (S10). Next, the control unit converts the analog values coming from the first and second FSR sensors of the sensor unit through the A / D converter into digital values, respectively (S12). Next, the control unit first determines whether the first FSR sensor is pressed at a pressure equal to or greater than the reference value based on the value coming from the first FSR sensor (S14). In this case, the control unit may determine whether there is a sensor pressed by a pressure of 50 or more levels among the values converted into 128 levels of 7 bits among 8-bit digital data by the A / D converter.

As a result of the determination, when it is determined that the first FSR sensor is pressed at a pressure equal to or greater than the reference value, the control unit divides the value received from the second FSR sensor into two and stores it in the memory to secure the most significant bit for indicating the moving direction (S16). . Then, the control unit sets the moving direction to the first direction, that is, the direction from the first FSR sensor to the second FSR sensor by inserting 1 into the most significant bit, and sets the moving speed to the resultant value obtained from the second FSR sensor (S18). ).

In addition, if it is determined that the first FSR sensor is not pressed at the pressure higher than the reference value, the control unit determines whether the second FSR sensor is pressed at the pressure higher than the reference value (S15). Next, the control unit secures the most significant bit for indicating the moving direction by dividing the value input from the first FSR sensor by 2 and storing it in the memory (S17). The control unit inserts 0 into the most significant bit to set the moving direction in the second direction opposite to the first direction, that is, the direction from the second FSR sensor to the first FSR sensor, and the moving speed is obtained from the first FSR sensor. Set to a value (S19).

In particular, in the above steps, the control unit detects the forward or backward direction according to the combination of the pressed order of the first FSR sensor and the second FSR sensor installed in a line. Here, the forward is, for example, when the user pushes the finger down from the top on the sensor unit mounted on the headset or the waist belt or the garment, and the reverse may correspond to the case when the user pushes the finger up from the bottom. This is shown in the table below.

Combination direction Most significant bit (bit 7) FSR1-> FSR2 Advance One FSR2-> FSR1 apse 0

On the other hand, if it is determined in step S15 that no sensor is pressed with a pressure equal to or greater than the reference value, the control unit repeatedly performs the determination process on the next output value of the A / D converter.

Next, the control unit transmits data about the speed and direction to the server or output device of the virtual environment connected to the system using the RS-232 protocol (S20). Here, the transmission type transmits 8-bits as an unsigned char type. In this case, it is preferable that the most significant bit contains direction information and the lower 7 bits indicate a speed.

As described above, the present invention has the advantage of using the two FSR sensors by converting the order and pressure of the sensors into directions and speeds to display and manipulate the direction and speed of the movement path with a single finger in a virtual environment.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

As described above, according to the present invention, it is possible to simply control the direction and speed of movement in a virtual environment by using two flexible pressure sensors without using a mouse or a joystick. In particular, one finger can control the direction and speed of movement in the virtual environment, thereby increasing user convenience. In addition, it is possible to reduce the size and weight of the overall system, which has the advantage of being convenient to carry.

Claims (10)

A first pressure sensor and a second pressure sensor of a flexible type for generating an analog signal for pressure applied from the outside to determine a moving direction and a moving speed in the virtual environment; And It includes a control unit having an A / D conversion unit for converting the analog signal having the information about the pressed order and the degree of pressure of the first and second pressure sensors into digital data of a predetermined step, The control unit is determined to be pressed when the degree of pressure converted into the digital data of the predetermined step is a predetermined value, The output of the A / D converter is divided by 2 so that the most significant bit is empty, and when the first pressure sensor is pressed first and the second pressure sensor is pressed later, 1 is output to the most significant bit, and the second pressure sensor is first. When pressed and the first pressure sensor is pressed later, it outputs 0 to the most significant bit, The virtual environment, characterized in that the movement direction in the virtual environment is determined by using the value output to the most significant bit, and the speed at the time of movement in the virtual environment by using the degree of pressure converted into the digital data of the predetermined step. Mobile system in The method of claim 1, Wherein the first and second pressure sensors are FSR sensors whose resistance decreases as the force applied to the active surface of the sensor increases. The method of claim 2, And the first and second FSR sensors corresponding to the first and second pressure sensors are disposed adjacent to each other in a line. The method of claim 3, wherein Each of the first and second FSR sensors, An upper flexible substrate having a semiconductor printed on the active region, A lower flexible substrate on which a pair of electrodes are printed on another active region facing the active region, and And a spacer bonded to the upper flexible substrate and the lower flexible substrate and having an opening corresponding to the active regions. The method of claim 1, And the A / D converter converts the input analog signal into digital data of 128 steps and outputs the degree of pressure. The method of claim 5, wherein The control unit, when dividing the degree of the pressure in 128 steps, the movement system in a virtual environment, characterized in that determined to be 50 or more depressed. delete delete The method of claim 1, And the control unit transmits the digital data to at least one of a server and an output device of the virtual environment through an RS-232 protocol. The method of claim 9, The RS-232 protocol includes an 8-bit digital data transmission type as an unsigned char type, the most significant bit of the 8 bits contains the direction information, and the remaining lower 7 bits indicate a speed. Mobile system in a virtual environment.

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