KR101103684B1 - Frequency dependent damping generation device for haptic interface and haptic interface drive control device having same - Google Patents

Abstract

The present invention relates to a frequency dependent damping generating device for a haptic interface and a haptic interface drive control device having the same. More specifically, the present invention provides a frequency dependent damping generating device for a haptic interface that can expand the impedance range that the haptic interface can stably display and adaptively change the range of the impedance, and a haptic interface having the same. It is about a drive control apparatus.

In order to achieve the above object, the present invention provides a frequency-dependent damping generating device used in a drive control device of a haptic interface, the high-pass filter for passing a high frequency signal of the input signal from the control unit for outputting a drive motor control signal ; And an adder for summing a signal from the controller and a signal passing through the high pass filter, wherein the high pass filter and the adder are provided in front of a power amplifier of the driving control device. Provided is a frequency dependent damping generating device.

Haptic, Haptic Interface, Drive Control, Impedance, Damping

Description

Frequency-dependent damping generation device for haptic interface and haptic interface driving control device having same {Frequency-Dependent Damping Generation Device for Haptic Interface, and Haptic Interface Control Device Therewith}

The present invention relates to a frequency dependent damping generating device for a haptic interface and a haptic interface drive control device having the same. More specifically, the present invention provides a frequency dependent damping generating device for a haptic interface that can expand the impedance range that the haptic interface can stably display and adaptively change the range of the impedance, and a haptic interface having the same. It is about a drive control apparatus.

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. An 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 velocity filtering that can affect this Z-Width, and point 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 by the damper is improved, and thus there is a disadvantage in that the user feels a constant impedance even in the free movement. As a result, the range of impedance that the haptic interface can represent is increased, but the aspect of transparency is weakened.

On the other hand, JS Mehling et al. Expanded the impedance range that the haptic interface can express by connecting analog damping circuits in which the damping value changes according to the input frequency in parallel with the motor. (JS Mehling, JE Colgate, and MA Peshkin, "Increasing the impedance range of a haptic display by adding electrical damping ", Proceedings of the First Joint Eurohaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pp. 257-262, 2005). In this case, the analog damping circuit consumes a portion of energy generated by the high frequency input, which reduces the instability caused by the high frequency input, thereby extending the range of impedance that the device can express.

1 is a circuit diagram in which an analog damping circuit is added to a conventional driving motor.

The circuit diagram according to FIG. 1 shows a configuration in which the analog damping circuit 5 is connected in parallel to the drive motors 1 and 3 (1 is an electric parameter of the motor and 3 is a back electromotive force of the motor). This circuit configuration aims to extend the range of impedances that the haptic interface can reliably represent by reducing high frequency inputs that can cause instability in the haptic interface. Meanwhile, in FIG. 1, the drive motors 1 and 3 serve to drive the haptic interface.

The interpretation of the circuit diagram according to FIG. 1 is as follows.

A drive motor (1, 3) impedance (z ₁ (s)) and the impedance (z ₂ (s)) of the analog damping circuit (5) of each can be represented by equation 1 and 2.

Then, the current flowing into the motor and the damping circuit can be expressed as Equation 3.

Since the counter electromotive force can be expressed as Equation 4, the torque generated by the drive motors 1 and 3 is expressed as Equation 5.

As can be seen in Equation 5, it can be seen that the motor torque T (s) uses the input current and the speeds of the drive motors 1 and 3 as inputs. Here, influence of the input current is impedance z will receive an influence of the _first (s) and z ₂ (s), for z ₁ (s) is therefore determined by the characteristic of the driving motor (1, 3) only z ₂ Only (s) should be appropriately selected to reduce the high-frequency current input. Therefore, since the additional analog damping is affected by the characteristics of the driving motor, when the driving motor is changed, it is disadvantageous that the analog damping must be changed according to the characteristics of the changed motor. In addition, as shown in Equation 5, even when the haptic interface is in the free movement state (I (s) = 0), the motor torque is generated according to the counter electromotive force proportional to the speed. There is a problem.

The present invention provides a frequency dependent damping generating device for a haptic interface that can expand the impedance range that the haptic interface can stably display and adaptively change its impedance, and a haptic interface drive control device having the same. The purpose.

In order to achieve the above object, the present invention provides a frequency-dependent damping generating device used in a drive control device of a haptic interface, the high-pass filter for passing a high frequency signal of the input signal from the control unit for outputting a drive motor control signal ; And an adder for summing a signal from the controller and a signal passing through the high pass filter, wherein the high pass filter and the adder are provided in front of a power amplifier of the driving control device. Provided is a frequency dependent damping generating device.

Preferably, a first linear half-wave rectifier for performing linear half-wave rectification is provided between the high pass filter and the adder.

More preferably, a second linear half-wave rectifier is provided between the adder and the power amplifier to perform the preceding half-wave rectification.

On the other hand, according to another aspect of the present invention, the present invention is a frequency dependent damping generating device used in the drive control device of the haptic interface, the first damping generating unit and the second damping generation provided between the control unit and the power amplifier part; A comparator for determining a sign of a control signal of the controller; And a switch unit for connecting one of the first damping generator and the second damping generator to a power amplifier under the control of the comparator, wherein the first damping generator and the second damping generator are respectively provided from the controller. A high pass filter for passing a high frequency signal of an input signal of an adder; an adder for summing a signal from the control unit and a signal passing through the high pass filter; The negative linear half-wave rectifier and the linear half-wave rectifier of the second damping generator provide a frequency dependent damping generator for the haptic interface, characterized in that the commutation characteristics are reversed.

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 generating device is connected to a signal stage instead of a power stage of the driving motor, various analog signal processing methods and the like can be used. Damping can be designed regardless of the parameter, so it can be applied more flexibly, and the resistance or capacitance of the circuit can be changed to adaptively generate damping.

In addition, according to the present invention, it is possible to avoid the problem of increasing the system inertia in the low frequency region caused by connecting the analog damping circuit to the power stage in the prior art, and improving the stability in the haptic interaction through the haptic interface. The range of impedances that the interface can reliably represent can be extended.

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 frequency varying damping element between the controller of the haptic interface and the power amplifier. 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 to adaptively generate damping. According to the present invention, it is possible to avoid the problem of increasing the system inertia in the low frequency region caused by connecting the analog damping circuit to the power stage in the prior art, and improving the stability in haptic interaction through the haptic interface. The range of impedance that can be displayed stably can be extended.

2 is a circuit diagram illustrating a basic concept of a frequency dependent damping generating device for a haptic interface according to a preferred embodiment of the present invention.

As described above, the present invention includes the damping generating device 20 in front of the power amplifier 10 of the driver for driving the driving motors 1 and 3.

Referring to FIG. 2, the power amplifier 10 has a relationship between an input voltage and a current as shown in Equation 6 below.

As shown in FIG. 2, when the damping generating device 20 configured as a filter is added to the front of the power amplifier 10, the torques of the driving motors 1 and 3 are expressed by Equation 7.

Equation 7 may be expressed as Equation 8 again.

According to Equation 8, it can be seen that the motor torque has only a voltage v as an input and no input due to counter electromotive force exists. Therefore, in the driving circuit as shown in FIG. 2, when the haptic interface is in the free motion state (V (s) = 0), the damping generation circuit does not affect the motor torque and does not affect the transparency in the free motion. It can be seen. In addition, in the case of FIG. 2, unlike the conventional method, the damping circuit can be designed regardless of the characteristics of the driving motor, thereby enabling a more flexible design. In addition, the adaptive damping circuit can be easily designed by changing the resistance and capacitance values of the damping circuit.

However, in the case of the driving circuit according to FIG. 2, due to the dynamic characteristics of the filter, the haptic interaction point shows a slow decrease of the output when falling from the virtual object, and the slow decrease of the output inhibits transparency in force reflection and generates unnecessary input. There are disadvantages that can compromise the stability of the system. To solve this problem, two linear half-wave rectifiers are added between the high pass filter and the adder, and between the adder and the power amplifier. In addition, the linear half-wave rectifier reduces the generation of energy generated by the filtering to help stability.

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

The damping generating device 20 is provided at the front end of the power amplifier 10 and performs a function of processing a signal from the controller 30 for controlling the drive motor of the haptic interface and then transmitting the signal to the power amplifier 10. In FIG. 3, the controller 30 generates a control signal for controlling the driving of the driving motor of the haptic interface, and the power amplifier 10 amplifies the control signal and transmits the control signal to the driving motor of the haptic interface. Do this. Accordingly, the controller 30 and the damping generating device 20 constitute a haptic interface driving control device.

Referring to FIG. 3, the damping generation device 20 includes a high pass filter 22, a first linear half-wave rectifier 24, an adder 26, and a second linear half-wave rectifier 28.

The high pass filter 22 performs a function of passing a high frequency signal from an input signal. The first linear half-wave rectifier 24 performs linear half-wave rectification on the signal passing through the high pass filter 22. The adder 26 performs a function of summing the signal from the control unit and the signal passing through the high pass filter 22 and the first linear half-wave rectifier 24. The second linear half-wave rectifier 28 performs a linear half-wave rectification function for the signal passing through the adder 26.

The combination of the high pass filter 22 and the adder 26 performs substantially the same function as the low pass filter.

Specific functions of the first linear half-wave rectifier 24 and the second linear half-wave rectifier 28 are clearly shown with reference to FIG. 4.

4A-4C are diagrams illustrating the function of the first and second linear half-wave rectifiers.

When the haptic interface is in contact with a virtual wall having high stiffness, the input signal from the controller and the signal (1-G _hpf (s)) passing through the high pass filter 22 and the adder 26 are applied. 4A illustrates a case in which a linear half-wave rectifier is not used, FIG. 4B illustrates a case in which a first linear half-wave rectifier 24 is used, and FIG. 4C illustrates a first linear half-wave rectifier 24 and a second linear half-wave rectifier 28. The case where all are used is shown.

Referring to FIG. 4A, when the linear half-wave rectifier is not used at all, the signal passing through the adder 26 slowly decreases after the haptic interface is separated from the virtual wall, resulting in a time delay and a negative impedance after the decrease. It can be seen. Negative impedance can feel as if a virtual object is pulling, presenting a different force to the user.

Referring to FIG. 4B, when the first linear half-wave rectifier 24 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. 4C, the use of the second linear half-wave rectifier 28 may eliminate negative impedance.

Meanwhile, as described above, in the present invention, the high pass filter 22 and the adder 26 are used instead of the low pass filter. The adder 26 is used due to the combination of the high pass filter 22 and the adder 26. It is possible to place the first linear half-wave rectifier 24 at the front end.

Next, a frequency dependent damping generating device for a haptic interface according to another exemplary embodiment of the present invention will be described.

The frequency-dependent damping generating device according to the present invention described above includes a linear half-wave rectifier, and thus has a disadvantage in that the output can be in only a positive or negative direction.

In order to solve this problem, the frequency dependent damping generating device for the haptic interface according to another embodiment of the present invention is characterized by including two damping generating units.

5 is a block diagram of a frequency dependent damping generation device for a haptic interface according to another preferred embodiment of the present invention.

The frequency dependent damping generating device 20 'for the haptic interface according to another embodiment of the present invention is provided between the control unit 30 and the power amplifier 10, and the first damping generating unit 20a and the second. It includes a damping generating unit 20b, and further includes a comparator 50 and a switch unit 60.

The configuration of the first damping generator 20a and the second damping generator 20b is the same as described with reference to FIG. 3. However, the linear half-wave rectifiers 24a and 28a included in the first damping generator 20a and the linear half-wave rectifiers 24b and 28b included in the second damping generator 20b are rectified as shown in FIG. 5. The characteristics are opposite to each other. For example, the linear half-wave rectifiers 24a and 28a included in the first damping generator 20a pass a signal when the input has a positive value and are included in the second damping generator 20b. Linear half-wave rectifiers 24b and 28b pass a signal when the input has a negative value.

The comparator 50 performs a function of determining the sign of the output signal of the controller 30. The switch unit 60 switches a function of switching one of the output signals of the first damping generator 20a and the second damping generator 20b to the power amplifier 10 under the control of the comparator 50. To perform. Accordingly, the comparator 50 causes the switch unit 60 to connect the first damping generator 20a and the power amplifier 10 when the sign of the output signal of the controller 30 is positive (+). When the sign of the output signal of 30 is negative, the switch 60 connects the second damping generator 20b and the power amplifier 10 to each other.

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 circuit diagram of adding an analog damping circuit to a conventional drive motor,

2 is a circuit diagram showing a basic concept of a frequency dependent damping generating device for a haptic interface according to a preferred embodiment of the present invention;

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

4A-4C illustrate the function of the first and second linear half-wave rectifiers,

5 is a block diagram of a frequency dependent damping generation device for a haptic interface according to another preferred embodiment of the present invention.

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

1 and 3: drive motor 10: power amplifier

20: damping generating device 22: high pass filter

24: first linear half-wave rectifier 26: adder

28 second linear half-wave rectifier 30 control unit

Claims (5)

delete In the frequency dependent damping generating device used in the drive control device of the haptic interface, A high pass filter for passing a high frequency signal among input signals from a controller for outputting a drive motor control signal; An adder for summing signals from the control unit and signals passing through the high pass filter; And A first linear half-wave rectifier provided between the high pass filter and the adder to perform linear half-wave rectification Including, And the high pass filter and the adder are provided in front of the power amplifier of the drive control device. The method of claim 2, And a second linear half-wave rectifier for performing the preceding half-wave rectification between the adder and the power amplifier. delete Haptic interface drive control device comprising a damping generating device according to claim 2.

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