KR101071357B1 - The Frequency-Dependent Damping Generation Device for improve contact hardness, and the method thereof - Google Patents

Abstract

Disclosed are a frequency dependent damping generating device and method for improving contact hardness. The apparatus for generating frequency dependent damping includes: a first contact enhancement unit configured to generate first force information to reduce high frequency information and improve contact hardness in force information corresponding to position information of a haptic interaction pointer (HIP); ; A second contact enhancement unit generating second force information for compensating initial contact hardness from the position information of the HIP; And a combination unit for combining and outputting the first force information and the second force information. As a result, the stability of the system can be improved by reducing the high frequency input to the haptic interface and performing linear half-wave rectification. In addition, the contact hardness is compensated using the position information of the haptic interaction pointer (HIP) to improve transparency of the haptic system.

Haptic, Haptic Interface, Drive Control, Impedance, Damping

Description

The frequency-dependent damping generation device for improve contact hardness, and the method

The present invention relates to a frequency dependent damping generating device and a method thereof, and more particularly, to a frequency dependent damping generating device and a method for improving the contact hardness.

The haptic interface used in human-computer interaction can provide a higher level of immersion by appropriately conveying tactile information generated according to the movement of the user's hand to the user. The haptic interface can be used not only as an input device like a computer mouse, but also as an output device capable of force reflection. The ideal haptic interface should be able to transparently transmit the impedance of the virtual object to the user when the device comes in contact with the virtual object, and should not transmit any impedance when the device is in free motion without contact. In practice, however, the performance of this haptic interface is affected by many factors.

JE Colgate et al. Proposed a performance index called Z-Width, which represents the dynamic range of impedance that the haptic interface can express while maintaining passivity (JE Colgate and GG Schenkel, "Passivity of a class"). of sampled-data systems: Application to haptic interfaces ", Journal of Robotic Systems, vol. 14 (1), pp. 37-47, 1997). In addition, we discussed sample-and-hold, interface inherent dynamics, encoder quantization, and speed filtering that can affect this Z-Width, and pointed out that the main influence is the inherent damping of the interface. The experiment also showed that the physical damper plays an important role in improving the Z-Width. However, when such a physical damper is applied, the resistance caused by the damper is always present, which causes a user to feel a constant impedance even in the case of free movement. As a result, the range of impedance that the haptic interface can represent is increased, but the aspect of transparency is weakened.

Stable haptic interaction with high hardness virtual objects remains a challenge in the field of haptic control. In an effort to solve this problem, various studies have been conducted to add various types of damping elements to the system, and there is a problem that the hardness of the virtual object felt by the user is lower than that of the actual virtual object. . However, when such a physical damper is applied, the resistance caused by the damper is always present, which causes a user to feel a constant impedance even in the case of free movement. As a result, the range of impedance that the haptic interface can represent is increased, but the aspect of transparency is weakened.

Stable haptic interaction with high hardness virtual objects remains a challenge in the field of haptic control. In an effort to solve this problem, various studies have been conducted to add various types of damping elements to the system. There is a problem that the hardness of the virtual object felt by the user is lower than that of the actual virtual object.

In order to solve the above problems, the present invention provides a frequency-dependent damping generating device which extends the impedance range that the haptic interface can express when the haptic interface is in contact with a virtual object and improves the contact hardness that the user actually feels. Provide a method.

In order to achieve the above object, the present invention provides a frequency dependent damping apparatus comprising: a first device for reducing high frequency information and improving contact hardness in force information corresponding to position information of a haptic interaction pointer (HIP); A first contact enhancer for generating force information; A second contact enhancement unit generating second force information for compensating initial contact hardness from the position information of the HIP; And a combination unit for combining and outputting the first force information and the second force information.

The first contact enhancing unit may further include: a damping generating unit configured to reduce the high frequency information in the force information corresponding to the HIP position information and output the damped force information; And a first weighting unit configured to generate the first force information by changing the damped force information with time.

The damping generation unit may include: a high pass filter unit configured to pass high frequency information among force information corresponding to the HIP position information; And an adder configured to add force information corresponding to the HIP position information and force information passing through the high pass filter unit.

The damping generator may further include a first linear half-wave rectifier configured to perform linear half-wave rectification on the force information output from the high pass filter.

The apparatus may further include a second linear half-wave rectifier that performs linear half-wave rectification on the force information output from the adder.

The second contact improving unit may further include: a position controller configured to determine third force information including speed information of the HIP from position information of the HIP; And a second weighting unit configured to generate the second force information by changing the third force information with time.

In addition, a speed calculation unit for calculating the speed information of the HIP from the position information of the HIP; And a hardness controller configured to determine the third force information based on the input HIP position information and the speed information of the HIP.

The combination unit outputs a combination of the first force information and the second force information for a predetermined time after the haptic interface contacts the virtual object, and outputs only the second force information after the predetermined time has elapsed. It is preferable.

On the other hand, the present invention to achieve the above object, the method of improving the contact hardness, in the method of improving the contact hardness between the haptic interface and the virtual object, the position information of the Haptic Interaction Pointer (Haptic Interaction Pointer (HIP)) Generating first force information by reducing high frequency information in corresponding force information; Generating second force information from the position information of the HIP; And combining the first force information and the second force information.

The generating of the first force information may include: outputting damped force information by reducing high frequency information in force information corresponding to position information of the HIP; And changing the damped force information with time to generate the first force information.

The outputting of the damped force information may include: passing high frequency information among force information corresponding to position information of the HIP; And summing force information corresponding to the position information of the HIP and information output in the passing step.

The outputting of the damped force information may further include performing linear half-wave rectification on the information output in the passing step.

The method may further include performing linear half-wave rectification on the force information output in the addition step.

The generating of the second force information may include determining third force information including speed information of the HIP from position information of the HIP; And changing the third force information with time to generate the second force information.

The determining of the first force information may include calculating speed information of the HIP from position information of the input Haptic Interaction Pointer (HIP); And determining the third force information by combining the input HIP position information and the speed information of the HIP.

The combining may be performed by combining the first force information and the second force information for a predetermined time after the haptic interface contacts the virtual object, and after the predetermined time elapses, only the second force information. It is preferable to output.

According to the present invention, it is possible to improve the stability of the system by performing a function of reducing the input of the high frequency input to the haptic interface. In addition, according to the present invention, since the frequency-dependent damping device is connected to a signal stage instead of a power stage of a driving motor, various analog signal processing methods may be used, thereby being applied more flexibly. It is possible to vary the resistance and capacitance of the circuit.

In addition, the linear half-wave rectification of the signal input to the haptic interface improves the contact hardness by improving stability in haptic interaction through the haptic interface, and reduces the contact hardness that decreases when the haptic interface and the virtual object are initially contacted. The transparency of the haptic system is improved by compensating using the location information of the haptic interaction pointer (HIP).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible, even if shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

The present invention is characterized by a frequency dependent damping generating device for extending the impedance range of a virtual environment that can be stably displayed using a haptic interface. The frequency dependent damping generating device adds a damping element that varies according to frequency between the control unit and the power amplifier unit of the haptic interface. The frequency dependent damping generating device improves the stability of the system by performing a function of reducing the high frequency input to the haptic interface.

Since the frequency dependent damping generator is connected to the signal stage instead of the power stage of the drive motor, various analog signal processing methods can be used and the damping can be designed regardless of the electrical parameters of the drive motor. It can be applied more flexibly, and it is possible to vary the resistance or capacitance of the circuit (Capacitance) is characterized by adaptive damping.

1 is a block diagram of a haptic interface drive control apparatus according to a preferred embodiment of the present invention.

The frequency dependent damping generating device 130 is provided at the front end of the power amplifier unit 150 and functions to process a signal from the controller 110 for controlling the drive motor of the haptic interface and then transfer the signal to the power amplifier unit 150. Do this. In FIG. 2, the controller 110 generates a control signal for controlling the driving of the driving motor of the haptic interface, and the power amplifier unit 150 amplifies the control signal and transmits the control signal to the driving motor of the haptic interface. Perform the function. Accordingly, the controller 110 and the frequency dependent damping generating device 130 constitute a haptic interface driving control device.

2 is a block diagram of a frequency dependent damping generating device according to an embodiment of the present invention.

As shown in FIG. 2, the frequency dependent damping generating device includes a first contact enhancer 210 to improve contact hardness and a second contact enhancer to improve initial contact hardness when contact between the haptic interface and the virtual object occurs. And a combination unit 230 that combines information output from the first and second contact enhancement units 210 and 220 to output force information for driving the haptic interface.

Specifically, the first contact enhancing unit 210 is divided into a damping generator 240 and a first weighting unit 250, and the damping generator 240 is a high pass filter unit 242 and a first linear half wave rectifier. 244, an adder 246, and a second linear half-wave rectifier 248.

The high pass filter 242 performs a function of passing high frequency information among force information corresponding to position information of a haptic interaction pointer (HIP). The first linear half-wave rectifier 244 performs linear half-wave rectification on the information passing through the high pass filter 242. The adder 246 adds the information passed through the first linear half-wave rectifier 244 and the force information corresponding to the position information of the HIP. The second linear half-wave rectifier 248 performs a linear half-wave rectification function for the information passed through the adder 246.

The combination of the high pass filter 242 and the adder 246 substantially performs the same function as the low pass filter.

Specific functions of the first linear half-wave rectifier 244 and the second linear half-wave rectifier 248 will be described in detail with reference to FIGS. 3A to 3C.

3A to 3C are diagrams for explaining the functions of the first and second linear half-wave rectifiers. FIG. 3A is a diagram illustrating input and output information of the damping generator when the first and second linear half wave rectifiers are not used, and FIG. 3B is a diagram illustrating a frequency response of the input and output information of the damping generator when only the first linear half wave rectifier is used. FIG. 3C is a diagram illustrating a frequency response to input / output information of a damping generator when both the first and second linear half-wave rectifiers are used.

Referring to FIG. 3A, when the linear half-wave rectifier is not used at all, the signal passing through the adder 246 slowly decreases after the haptic interface is dropped from the virtual object, and a time delay occurs. After the decrease, the negative impedance is generated. Can be confirmed. Negative impedance can give the impression of a virtual object pulling, giving the user a feeling that is different from the real one, which reduces transparency.

Referring to FIG. 3B, when the first linear half-wave rectifier 244 is used, the impedance decreases rapidly. This makes the system more stable by reducing the magnitude of the total energy input by bringing it closer to the actual impedance output and increasing transparency and suppressing the generation of energy by undesirable inputs.

In addition, referring to FIG. 3C, when the second linear half-wave rectifier 248 is also used, the negative impedance may be removed.

Meanwhile, in the present invention, the high pass filter unit 242 and the adder 246 are used instead of the low pass filter. The adder 246 is used due to the combination of the high pass filter unit 242 and the adder 246. ), The first linear half-wave rectifier 244 may be disposed at the front end.

Meanwhile, as shown in FIG. 3C, even if the damping generator 240 includes the first and second linear half-wave rectifiers 244 and 248, the reaction force gradually increases upon initial contact between the haptic interface and the virtual object. It can be seen that the hardness felt.

The first weighting unit 250 assigns and outputs a weight of a constant value to the force information output from the first contact enhancing unit 240. Since the first contact enhancer 240 is preferably applied after a predetermined time has elapsed after the haptic interface is in contact with the virtual object, it is preferable to give a weight as shown in Equation 1 below.

는 초기 접촉이 발생한 시간이며,

는 초기 접촉시의 경도를 향상시키고자 하는 시간 간격이다.

는 설계자 등에 의해 가변될 수 있다. here,

Is the time when the initial contact occurred,

Is the time interval to improve the hardness at initial contact.

Can be varied by the designer or the like.

That is, the first weight unit 250 may change the force information output from the damping generator 240 according to time and apply it to the combination unit 230.

The second contact improving part 270 of FIG. 2 is for improving the contact hardness at the time of initial contact, and includes a position controller 260 and a second weight part 270. The position controller 2600 includes a speed calculator 262 and a hardness determiner 264.

The speed calculator 262 calculates the speed of the HIP from the position information of the haptic interaction pointer (HIP). The speed of the HIP can be calculated by differentiating the HIP position by time. The hardness controller 264 calculates force information for improving hardness at initial contact by using the HIP position information and the speed information calculated by the speed calculator 262.

)를 산출하는 것이 바람직하다.Hardness control unit 264 is the force information (Equation 2)

Is preferably calculated.

는 HIP의 위치 정보이고, 는 초기 접촉시의 HIP의 위치 정보 혹은 가상 물체의 경계(boundary) 정보이다. 그리고, 는 가상물체의 강성(stiffness) 값이고, 는 가상물체의 점성(viscosity) 값이다.here,

Is the location information of the HIP, and is the location information of the HIP at the initial contact or the boundary information of the virtual object. Is the stiffness value of the virtual object and is the viscosity value of the virtual object.

The second weighting unit 270 gives a weight of a predetermined value to the force information output from the position control unit 2600 and outputs the weighted value. Since the second contact enhancement unit 220 preferably affects the contact hardness within a predetermined time after the haptic interface and the virtual object are in contact with each other, it is preferable to give a weight as shown in Equation 3 below.

The combiner 230 combines the information output from the first weight unit 250 and the information output from the second weight unit 270 as shown in Equation 4 below.

As such, when the force information is corrected for a predetermined time during initial contact, the contact hardness felt by the user is improved.

4A and 4B show the stiffness displayed on the haptic interface during initial contact of the haptic interface and the virtual object. In detail, FIG. 5A is a diagram showing the stiffness when the position control is not applied at the time of initial contact, and FIG. 5B is a diagram showing the stiffness when the position control is applied at the time of initial contact.

As shown in Figures 4a and 4b it can be seen that the application of position control increased the stiffness much faster during initial contact.

5A and 5B are diagrams illustrating a hardness of a contact felt by a user during initial contact between a haptic interface and a virtual object. In detail, FIG. 5A illustrates a contact strength felt by the user when the first weight portion and the second contact enhancement portion are not applied during the initial contact, and FIG. 5B illustrates the first weight and the second contact enhancement portion during the initial contact. It is a figure which shows the contact intensity which a user feels when it is applied.

Therefore, when the haptic interface and the virtual object contact, it can be seen that the stiffness felt by the user is significantly increased by adjusting the force information provided to the haptic interface based on the HIP position at the initial contact.

 In the present embodiment, the equation for the force information of the second contact improving unit 220 generated to improve the initial contact hardness is not limited thereto. In addition, of course, the equations for the first and second weights that change according to the time of the first weighting unit 250 and the second weighting unit 270 also correspond to a preferred embodiment.

6 is a block diagram of a frequency dependent damping generating device 130 for a haptic interface according to another embodiment of the present invention.

In the frequency dependent damping generator 130 of FIG. 6, the first and second sample and hold units 241 and 249 are added to the frequency dependent damping generator 130 of FIG. 3.

The first sample and hold unit 241 converts force information, which is an input analog signal, into a digital signal. In addition, the high pass filter 242, the first linear half-wave rectifier 244, the adder 246, and the second linear half-wave rectifier 248 of FIG. 7 may be implemented to process digital signals. . Since the high pass filter 242, the first linear half-wave rectifier 244, the adder 246, and the second linear half-wave rectifier 248 process digital signals, a damping generator ( The flexibility of the 240 may be improved and noise may be less generated.

In addition, the high pass filter 242 of FIG. 6 is preferably implemented as a digital Butterworth filter, and the adder 246 and the first and second half-wave rectifiers can be easily implemented through a soft program. Do.

The second sample-and-hold unit 249 converts the digital signal output from the second linear half-wave rectifying unit 248 into an analog signal and outputs the analog signal.

7 is a block diagram of a frequency dependent damping generating device according to another preferred embodiment of the present invention.

The frequency dependent damping generating device according to another embodiment of the present invention includes two damping generating devices 720 and 740, and further includes a comparator 760 and a switching unit 780.

The configuration of the two damping generating devices 720 and 740 is the same as that of the frequency dependent damping generating device 130 described with reference to FIG. 3. However, the rectification characteristics of the linear half-wave rectifier included in the first contact enhancement part 720a and the linear half-wave rectifier included in the first contact enhancement part 740a are opposite to each other. For example, the linear half-wave rectifier included in the first contact enhancer 720a passes a signal when the input has a positive value, and the linear half-wave rectifier included in the second contact enhancer 740a receives an input. Pass this signal if it has a negative value.

The comparator 760 performs a function of determining the sign of the output signal of the controller 110. The switching unit 780 is configured to switch any one of the output signals of the first damping generator 720 and the second damping generator 740 to the power amplifier 150 under the control of the comparator 760. Perform the function. Accordingly, the comparison unit 760 causes the switching unit 780 to connect the first damping generator 7200 and the power amplifier unit 150 when the sign of the output signal of the controller 110 is positive (+). When the sign of the output signal of the controller 110 is negative, the switching unit 780 connects the second damping generating device 7400 and the power amplifier unit 150.

Thus, the frequency dependent damping generator of FIG. 7 has an effect of controlling the power amplifier unit irrespective of the sign of the output signal of the controller.

8 is a flowchart illustrating a method of improving contact hardness of a frequency dependent damping device according to an embodiment of the present invention.

The high pass filter 242 of the frequency dependent damping device 130 passes high frequency information among force information corresponding to position information of a haptic interaction pointer (HIP) (S810).

In addition, the first linear half-wave rectifier 244 performs linear half-wave rectification on the information passing through the high pass filter 242 (S820), and the adder 246 passes through the first linear half-wave rectifier 244. One piece of information and force information corresponding to the location information of the HIP are summed (S830). The combination of the high pass filter 242 and the adder 246 substantially performs the same function as the low pass filter. However, by arranging the first linear half-wave rectifier 244 between the high pass filter and the adder 246, not only transparency can be increased but also the total energy input to the haptic interface can be reduced to stabilize the haptic system.

The second linear half-wave rectifier 248 performs a linear half-wave rectification function for the information passing through the adder 246 (S840). By using the second linear half-wave rectifier 248, the negative impedance of the haptic interface may be removed.

The first weighting unit 250 assigns and outputs the force information output from the second linear half-wave rectifying unit 248 with a first weight changed according to time (S850).

Meanwhile, the speed determiner of the second contact enhancer 220 receives the position information of the haptic interaction pointer (HIP) and calculates the speed information of the HIP (S860).

In addition, the hardness controller 264 calculates force information for improving hardness at initial contact by using the HIP position information and the speed information calculated by the speed calculator 262 (S870).

The second weighting unit 270 gives the force information output from the hardness control unit 264 to give a second weight that is changed in time (S880).

Finally, the combiner 230 combines the information output from the first weight unit 250 and the second weight unit 270 as shown in Equation 4 below (S890). In detail, when the haptic interface and the virtual object contact each other, the combination unit 230 sums and outputs information output from the first weight unit 250 and the second weight unit 270 during the initial contact time. After the elapse of time, only the information output from the first weighting unit 250 is output. Thus, the force information output from the frequency dependent damping generating device 130 may improve the contact hardness. In addition, the initial contact time may be changed by the user.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a block diagram of a haptic interface drive control device according to an embodiment of the present invention;

2 is a block diagram of a frequency dependent damping generating device according to an embodiment of the present invention;

3A to 3C are diagrams for explaining the functions of the first and second linear half-wave rectifiers;

4A and 4B show the stiffness displayed on the haptic interface upon initial contact of the haptic interface with the virtual object,

5a and 5b are views showing the contact strength felt by the user during the initial contact of the haptic interface and the virtual object,

6 is a block diagram of a frequency dependent damping generating device for a haptic interface according to another embodiment of the present invention;

7 is a block diagram of a frequency dependent damping generating device according to another preferred embodiment of the present invention;

8 is a flowchart illustrating a method of improving contact hardness of a frequency dependent damping device according to an embodiment of the present invention.

<Description of reference numerals for the main parts of the drawings>

110: control unit 130: frequency dependent damping generating device

150: power amplifier unit 210: contact enhancement unit

220: initial contact improving unit 230: combination unit

240: dangping generation unit 250: first weighting unit

260: position control unit 280: second weighting unit

Claims (16)

A first contact enhancement unit generating first force information for reducing high frequency information and improving contact hardness in force information corresponding to position information of a haptic interaction pointer (HIP); A second contact enhancement unit generating second force information for compensating initial contact hardness from the position information of the HIP; And And a combiner for combining and outputting the first force information and the second force information. The method of claim 1, The first contact improving unit, A damping generator for reducing the high frequency information from the force information corresponding to the HIP position information and outputting the damped force information; And And a first weighting unit configured to change the damped force information with time to generate the first force information. 3. The method of claim 2, The damping generating unit,  A high pass filter configured to pass high frequency information among force information corresponding to the HIP position information; And And an adder configured to add the force information corresponding to the HIP position information and the force information passing through the high pass filter unit. 2. The method of claim 3, The damping generator And a first linear half-wave rectifier for performing linear half-wave rectification on the force information output from the high pass filter. The method of claim 3, And a second linear half-wave rectifier for performing linear half-wave rectification on the force information output from the adder. The method of claim 1, The second contact improving unit, A position control unit for determining third force information including the speed information of the HIP from the position information of the HIP; And And a second weighting unit configured to generate the second force information by changing the third force information according to time. The method of claim 6, A speed calculator configured to calculate speed information of the HIP from position information of the HIP; And And a hardness controller configured to determine the third force information based on the input HIP position information and the speed information of the HIP. The method of claim 1, The combination part After the haptic interface comes into contact with the virtual object, the first force information and the second force information are combined and output for a predetermined time, And outputting only the second force information after the predetermined time has elapsed. In the method of improving the contact hardness between the haptic interface and the virtual object, Generating first force information by reducing high frequency information in force information corresponding to position information of a haptic interaction pointer (HIP); Generating second force information from the position information of the HIP; And And combining the first force information and the second force information. The method of claim 9, The first force information generation step, Outputting damped force information by reducing high frequency information in force information corresponding to the position information of the HIP; And And changing the damped force information with time to generate the first force information. The method of claim 10, The step of outputting the damped force information,  Passing high frequency information among force information corresponding to the position information of the HIP; And And summing force information corresponding to the position information of the HIP and information output in the passing step. The method of claim 11, The step of outputting the damped force information, And performing linear half-wave rectification on the information output in the passing step. The method of claim 11, And performing linear half-wave rectification on the force information output in the summing step. The method of claim 9, Generating the second force information, Determining third force information including velocity information of the HIP from position information of the HIP; And And changing the third force information with time to generate the second force information. 15. The method of claim 14, Determining the first force information, Calculating velocity information of the HIP from position information of the input Haptic Interaction Pointer (HIP); And And determining the third force information by combining the input HIP location information and the speed information of the HIP. The method of claim 9, The combining step After the haptic interface contacts the virtual object, the first force information and the second force information are combined and output for a predetermined time, And after the predetermined time has elapsed, outputting only the second force information.

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