JPH08137608A - Three-dimensional coordinate input device - Google Patents

Abstract

(57) [Summary] [Purpose] To remove the effects of hand shaking and camera shake from a series of measured 3D coordinate values and calculate the 3D coordinate values intended by the user. [Structure] Three-dimensional position designating unit 1 for designating an arbitrary position
And a three-dimensional position measuring unit 2 for detecting the three-dimensional coordinates thereof. The detected three-dimensional coordinates are given to the arithmetic and control unit 4 via the control unit 3, signal processing equivalent to that of a low pass filter is performed, and converted into smoothed three-dimensional coordinate values. A smoothness input device 18 and a threshold designating device 19 are provided so that the smoothness of the measurement data and the threshold for error determination can be designated according to the user's intention. By doing so, even if the input coordinate changes due to shaking of the hand or camera shake, the three-dimensional coordinate value intended by the user can be obtained.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a computer-aided design system (CAD), a virtual reality system (VR), or a three-dimensional shape measuring system, which requires three system users.
The present invention relates to a three-dimensional coordinate input device used when inputting three-dimensional coordinates.

[0002]

2. Description of the Related Art In recent years, the concept of virtual reality has spread,
It has come to be applied to various fields. For example, in the field of CAD for creating and modifying three-dimensional shape data, a device for creating and modifying a three-dimensional shape by a more direct operation has been developed. For example, US POLHEMUS "3S"
"PACE system" is a three-dimensional coordinate input device that applies magnetic conversion technology, and is a US SCIENCE ACCESS.
ORIES "GP-12 series" is a three-dimensional coordinate input device to which ultrasonic technology is applied, and all the devices are on sale.

In these three-dimensional coordinate input devices, a three-dimensional coordinate designating section having the shape of a pen, a sensor section for measuring the existing position of the three-dimensional coordinate designating section, and a signal from the sensor section are converted into coordinate values. In many cases, the control unit outputs the coordinate values to a computer system or the like.

The conventional three-dimensional coordinate input device as described above will be described with reference to FIG. FIG. 13 shows the configuration of a conventional three-dimensional coordinate input device (3SPACE system), which has a three-dimensional coordinate designating section 91, a sensor section 92, and a control section 93. When inputting the coordinates, the user holds the three-dimensional coordinate instructing unit 91 and moves it to a desired position in the real space. Then, the sensor unit 92 outputs coordinate data to the control unit 93 according to the position of the three-dimensional coordinate designating unit 91.

The control unit 93 calculates a three-dimensional coordinate value from the coordinate data of the sensor unit 92 and outputs it to the computer system connected to the control unit 93. When the user moves the three-dimensional coordinate designating section 91, the output of the sensor section 92 changes, and the three-dimensional coordinate value output from the control section 93 also changes accordingly. In this way, the three-dimensional coordinate values can be continuously input to the computer system. For example, when the user wants to input a straight line, if the three-dimensional coordinate designating section 91 is linearly moved, the control section 93 outputs a desired three-dimensional coordinate value on the straight line.

[0006]

However, in the above-mentioned three-dimensional coordinate input device, the intended three-dimensional coordinate value can be obtained due to the measurement error of the device and the shaking of the user's hand or camera shake. There was a problem that it did not exist.

The present invention has been made in view of such conventional problems, and the measured three-dimensional coordinate data is not directly used but is smoothed into a series of measured three-dimensional coordinate data. Provided is a three-dimensional coordinate input device capable of calculating three-dimensional coordinate values by removing the effects of hand shake and camera shake by inputting processing and inputting the three-dimensional coordinate values intended by the user into a computer system. The purpose is to

[0008]

The invention of claim 1 of the present application is, as shown in FIG. 1, a three-dimensional coordinate designating section 1 for designating an arbitrary three-dimensional position and a position of the three-dimensional coordinate designating section 1. A three-dimensional coordinate measuring unit 2 for measuring a coordinate value and a control unit 3 for generating coordinate values from the measurement result of the three-dimensional coordinate measuring unit 1.
It is a dimensional coordinate input device, and has a calculation control unit 4a including a position smoothing unit 5 that smoothes by a calculation based on a plurality of coordinate values generated by the control unit 3 so that changes in coordinate values are smooth. It is characterized by that.

In the invention of claim 2 of the present application, the position smoothing means 5 is a digital filter which inputs the measured three-dimensional coordinate values and outputs the smoothed coordinate values. Is.

According to the invention of claim 3 of the present application, the position smoothing means 5 designates the pass band of the digital filter even during operation, thereby freely designating and changing the smoothness degree. It is characterized by comprising means 7.

In the invention of claim 4 of the present application, the position smoothing means 5 is provided with the smoothing index designating means 6 for freely designating and changing the smoothness degree of the coordinate value even during operation. It is a feature.

In the invention of claim 5 of the present application, the arithmetic control unit 4
a is a difference value between the coordinate value p measured by the three-dimensional coordinate measuring unit 2 and the coordinate value p ′ calculated by the position smoothing means 5, which is compared with a predetermined threshold value. If it is larger than the calculated coordinate value p ′, the error comparison means 8 for designating the measured coordinate value p as the input coordinate value is provided.

In the invention of claim 6 of the present application, the arithmetic control unit 4
a is the error comparison means 8 even during the measurement of the three-dimensional coordinates.
It is characterized by comprising a threshold value specifying means 9 for freely selecting and changing the threshold value.

According to a seventh aspect of the present invention, as shown in FIG. 2, a three-dimensional coordinate designating section 1 for designating an arbitrary three-dimensional position.
A three-dimensional coordinate input device comprising: a three-dimensional coordinate measuring unit 2 for measuring the position of the three-dimensional coordinate pointing unit 1; and a control unit 3 for generating coordinate values from the measurement result of the three-dimensional coordinate measuring unit 2. Therefore, based on the plurality of coordinate values generated by the control unit 3, a speed calculation unit 10 that calculates a speed that is a change amount of the position per unit time, and a plurality of speed values calculated by the speed calculation unit 10. The velocity smoothing means 11 that smoothes the movement speed of the three-dimensional coordinate designating section 1 based on the above so as to smooth the change, and a new coordinate value is calculated based on the velocity calculated by the velocity smoothing means 11. The calculation control unit 4b including the coordinate value calculation means 12 is provided.

In the invention of claim 8 of the present application, the speed smoothing means 11 is a smoothing index specifying means for freely specifying and changing the smoothness degree of the speed value even when the speed smoothing means 11 is in operation. It is characterized by including 13.

In the invention of claim 9 of the present application, the speed smoothing means 11 is a digital filter which inputs the three-dimensional speed value calculated by the speed calculating means 10 and outputs the output as a smoothed speed value. It is characterized by being.

According to the invention of claim 10 of the present application, the speed smoothing means 11 specifies the pass band of the digital filter even during operation, thereby freely specifying and changing the smoothness degree. It is characterized by comprising means 14.

[0018]

According to the invention of claim 1 of the present application having such a feature, the user moves the three-dimensional coordinate designating section in an arbitrary three-dimensional space and designates its position. Then, the three-dimensional coordinate measuring unit measures the position of the three-dimensional coordinate pointing unit. When the three-dimensional coordinate designating unit moves between a plurality of positions to be measured and accompanied by unnecessary fine movement, the position smoothing means of the arithmetic control unit is set to three.
Based on the plurality of measured coordinate values measured by the dimensional coordinate measuring unit, smoothing is performed by calculation so that the change in the coordinate values becomes smooth.

According to the second aspect of the present invention, the user moves the three-dimensional coordinate designating section in an arbitrary three-dimensional space and designates its position. Then, the three-dimensional coordinate measuring unit measures the position of the three-dimensional coordinate pointing unit. When the three-dimensional coordinate instruction unit moves between a plurality of positions to be measured and involves unnecessary fine movement, the speed calculation means of the arithmetic control unit causes the three-dimensional coordinate measuring unit to measure the plurality of measured coordinate values already measured. The speed of the three-dimensional coordinate designating section is calculated based on Next, the speed smoothing means is based on the plurality of speed values calculated by the speed calculating means,
Smoothing is performed by calculation so that the change in the moving speed of the three-dimensional coordinate designating unit becomes smooth. Then, the coordinate value calculation means calculates a new coordinate value based on the speed calculated by the speed smoothing means. In this way, the user's intention is estimated from the speed change of the three-dimensional coordinate designating section, and the influence of a slight change due to hand shaking or camera shake is reduced.

According to the second and ninth aspects of the present invention, the measured three-dimensional coordinate values or the already calculated speeds are removed in order to eliminate the influence of minute and rapid changes due to hand shaking and camera shake. Enter the value into the digital filter. Then, the output result of the digital filter is used as the three-dimensional coordinate value or the latest speed value.

Further, according to the invention of claims 4 and 8 of the present application, by changing the degree of smoothness and its value by the smoothing index designating means, it is flexible even when the usage condition of the three-dimensional coordinate designating section is changed. I am able to deal with.

According to the third and tenth aspects of the present invention, by designating the pass band of the filter by the filter characteristic designating means, it is possible to flexibly cope with a change in the use condition of the three-dimensional coordinate designating section. I have to.

According to the fifth and sixth aspects of the invention, the error comparing means determines whether or not the three-dimensional coordinate value is input according to the user's intention. Then, by giving the threshold of the threshold designating means to the error comparing means, it is determined that the measured coordinate values are due to hand shaking or camera shake when the three-dimensional coordinates to be input change abruptly. This makes it possible to output a three-dimensional coordinate value that reflects the user's intention.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-dimensional coordinate input device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing the overall configuration of the three-dimensional coordinate input device of this embodiment. As shown in the figure, the three-dimensional coordinate input device includes a three-dimensional coordinate pointing unit 1 and a sensor unit 3 as in the conventional example.
A dimensional coordinate measuring unit 2 and a control unit 3 are provided.

The three-dimensional coordinate measurement value output from the control unit 3 is given to the calculation control unit 4. The arithmetic control unit 4 includes a storage device 15, an arithmetic device 16, a central processing unit 17, a smoothness input device 18, and a threshold value designation device 19. The storage device 15 is a memory that stores an input three-dimensional coordinate measurement value, a program of a smoothing procedure (algorithm) described below, and constants and variables necessary for executing the program. The arithmetic unit 16 is a device that calculates the smoothed three-dimensional coordinate value by using the measurement value of the three-dimensional coordinate input via the central processing unit 17 and performing arithmetic operation by a program of a predetermined smoothing procedure. .

The central processing unit 17 stores the memory device 15 and the arithmetic device 16 so that the arithmetic device 16 can execute the smoothing operation based on the program stored in the memory device 15.
Is a device for controlling the. The smoothed three-dimensional coordinate values are output from the central processing unit 17 to an external computer system such as CAD. A smoothness input device 18 and a threshold designation device 19 are connected to the central processing unit 17. The smoothness input device 18 is a device in which the user inputs the smoothness with respect to the measured values of the three-dimensional coordinates at any time. The threshold designation device 19 is 3
It is a device for designating a threshold value for determining an error in a dimensional coordinate value.

First, the operation principle of the three-dimensional coordinate input device will be described. The central processing unit 17 follows the designated smoothness when there is an input from the smoothness input device 18,
The constant used for the smoothing calculation is changed and stored in a predetermined position of the storage device 15. After that, the arithmetic unit 16 performs the smoothing operation using the changed constant. User calculated 3
Threshold value designating device 1 for threshold value used when comparing the difference between the three-dimensional coordinate value and the measured three-dimensional coordinate value at an arbitrary timing
Enter in 9. The threshold value input by the threshold value designation device 19 is sent to the central processing unit 17, and is stored in a predetermined position of the storage device 15 via the central processing unit 17. In the three-dimensional coordinate input device of the present embodiment, it is assumed that the three-dimensional coordinate value is measured at fixed time intervals T and the measured value is sequentially input to the storage device 15.

Now, the operation of the three-dimensional coordinate input device according to the first and second aspects will be specifically described by using mathematical expressions and a flow chart. Here, a low pass filter is used as the smoothing method. As an example of the low pass filter, there is a Butterworth type low pass filter as shown in FIG. The cutoff frequency ω _c of this filter is 1
k radians / second, and the sampling frequency f _s of the input signal is 1 kHz. Transfer function H of this low pass filter
(Z) can be given by the following equation (1) (“Digital Signal Processing” by Sei Imai, Sangyo Shuppan, 1980, No. 5).
See Chapter).

[0029]

[Equation 1] Here, Z ⁻ⁿ (n = 0, 1, 2, ...) Indicates Z conversion in the digital filter, and means a time delay of n units in the sampled input signal.

In the equation (1), the fractional expression of the first term on the right side represents the characteristic of the first partial filter, and the fractional expression of the second term on the right side represents the characteristic of the second partial filter. A general circuit configuration of the partial filter is shown in FIG. In this partial filter, delay circuits Z ^-1 are cascade-connected in two stages, multipliers of tap coefficients b _k2 and b _k3 are connected to the feedback side, and tap coefficients c _k1 and c _k2 are connected to the feed forward side.
The multiplier of c _k3 is connected.

FIG. 5 is a circuit diagram showing a specific configuration of the low pass filter (digital filter) 20 of this embodiment, in which two partial filters shown in FIG. 4 are provided in parallel. In the first partial filter 20A, the delay circuit (Z ^-1 )
A multiplier 22 having a tap coefficient c ₁₁ is connected to the input end of 21 and a multiplier 23 having a tap coefficient b ₁₂ is connected to the output end. The output end of the multiplier 23 is connected to the input terminal 20a via the inverting circuit (-1) 24, and the output end of the multiplier 22 is connected to the output terminal 20b of the low pass filter 20.

In the second partial filter 20B, two delay circuits 25 and 26 are connected in series, and the input terminal 20
The signal of a is given to the input terminal of the delay device 25. Delay device 2
Multipliers 27 and 28 having tap coefficients c ₂₁ and c ₂₂ are connected to the input terminal and the output terminal of 5, respectively. The input terminal and the output terminal of the delay device 26 have multipliers 2 with tap coefficients b ₂₂ and b ₂₃ , respectively.
9, 30 are connected. The output terminals of the multipliers 27 and 28 are both connected to the output terminal 20b, and the output terminals of the multipliers 29 and 30 are both connected to the input terminal 20a via the inverting circuit 31.

The value of the tap coefficient of the low-pass filter 20 (hereinafter simply referred to as coefficient) is shown in the following equation (2). c ₁₁ = 1.0 b ₁₂ = -0.3679 c ₂₁ = -1.0 b ₂₂ = 0.7860 ... (2) c ₂₂ = 0.6597 b ₂₃ = 0.3679

Now, the smoothing processing procedure based on the equation (1) will be described. FIG. 6 shows the low-pass filter 20,
Output value (smooth coordinate value) X for input value (coordinate value) X _n
'Is a flowchart for calculating _n. To simplify the explanation, only the x coordinate will be explained, but y,
The z coordinate is also smoothed in the same manner.

The x coordinate of the measured coordinate value (input value) at time T _n (T _n = n × Δt; n is a non-negative integer, Δt is a measurement interval of the coordinate value, and is 1 millisecond here) Let X _n be a smoothed coordinate value (output value) obtained by smoothing, and be X ′ _n . Expression (1) means that the two partial filters 20A and 20B are connected in parallel. The outputs of the two partial filters at time T _n are U _kn (k = 1, 2).
W _k0 , W _k1 , and W _k2 are filter inputs at times T _n , T _n-1 , and T _n-2 of the respective partial filters.

In FIG. 6, when measurement is first started, n = 0 is set as shown in step S20. Then, in step S21, when n = 0, W _k0 = W _k1 = W _k2 = 0.0 and the filter input is initialized. Therefore, the next step S
The first output value _X'n at 22 is 0.0. Now, in step S23, k = 1 is set, and the value of the first item of the equation (1) (first
The partial filter 20A) is calculated. That is, step S
Proceeding to 24, the product sum value bw on the denominator side of the first item is obtained. However, when k = 1, b _k3 = 0.

When the process proceeds to step S25, the calculation result bw of step S24 is subtracted from the input value X _n , and the value is W _k0
And Thus, the time T _{n of} the first partial filter 20A
The input W _{k0 at} is calculated. Next, in step S26, the sum of products on the numerator side of the first item in equation (1) is calculated based on the input W _k0 , W _k1 , and W _k2 . Next step S
In 27, the output U of the part filter _X'n already obtained
_k is added to obtain the total output value _X'n. Next time T
_In preparation for _{n + 1} , the process proceeds to step S28, where the inputs W _k1 and W _k0 of the low-pass filter 20 are shifted, and their values are W _k2 and W _k2 , respectively.
_Let W _k1 .

Next, in step S29, the value of k is incremented. If k does not exceed 2, the process returns from step S30 to step S24. When k = 2, the output of the second partial filter 20B is calculated. Also in the second partial filter 20B, the same calculation as in steps S24 to S30 is performed, and when the calculation is completed, the process proceeds to step S31,
And outputs the smoothed coordinate values _X'n from the output terminal 20b. 1
When the calculation for the second time is completed, the process proceeds to step S32, and the value of n is counted up. In this way, the input coordinate values are fetched up to a predetermined number of times, and when a series of coordinate input is completed in step S33, the calculation processing in the low-pass filter 20 ends.

In the above arithmetic processing, steps S20-
The process of S33 achieves the function of the position smoothing unit 5 that smoothes by a calculation based on the plurality of coordinate values generated by the control unit 3 so that the change in the coordinate values is smooth.

[0040] In this way, the smoothed coordinate value _X'n is obtained. _Y'n similarly calculates the _Z'n, calculating the coordinate value at time _{T n P'n = (X'n} , Y'n, Z'n) determined. Series of the calculated coordinate value _P'n are sequentially outputted from the low-pass filter represented by equation (1). In this way, the effects of randomly generated hand tremors, measurement errors, etc. are eliminated, and smoothly changing three-dimensional coordinate values are obtained.

Next, the operation of the three-dimensional coordinate input device according to the seventh and ninth aspects will be described using mathematical expressions and a flow chart. FIG. 7 is a flowchart for calculating the output value with respect to the input value in the low pass filter 20 in order to process the change in the coordinate value as the speed. As shown in step S40 in the figure, when the measured coordinate values at time T _n set to P _n, the change of the coordinate value per unit time at the time T _n, i.e. the rate V _n is, P _n and P _It is the difference from _n-1 . The x-axis component of the velocity V _n X _n, the smoothed x-axis component and _X'n. The transfer function of the low-pass filter 20 used for smoothing is defined in (1) described above.

As shown by the broken line portion in FIG. 7, the output is calculated for each of the first and second partial filters in the processing of steps S41 to S49 as in the case of FIG. In step S42, k = 1 is set and the calculation is started from the partial filter 20A of the first item of the equation (1). As shown in step S43, the denominator-side coefficient b _ki (i = 2, 3) and time T =
The product sum value bw with the output W _{k (i-1)} before n is _obtained . In the next step S44, this result bw is subtracted from the input value X _n, and the input W for the partial filter k = 1 at the time T _n is obtained.
Calculate the value of _k0 .

In step S45, the numerator side coefficient c _ki (i) is applied to the W _k0 , W _k1 , and W _k2 thus obtained.
= 1, 2, 3), and this value is used as the output U _{k of the} partial filter. In step S46, the value of the output U _k of the partial filter is added to the already obtained output value X ′ _n in order to obtain the overall output X ′ _n . Next step S
At 47, the inputs W _k1 and W _k0 are shifted in preparation for the time T _{n + 1} , and the values are used as new inputs W _k2 and W _k1 . Then, in step S48, the value of k is counted up in order to obtain the output of the next partial filter.

In this way, the processes from step S43 to step S49 are repeated until the calculation of all the partial filters is completed. When the calculation of the x coordinate of the low-pass filter 20 is completed in step S49, the next routine S
In step S50, the y-axis component and the z-axis component are calculated respectively. Then, in a final step S52, the smoothed velocity component _{(X'n, Y'n, Z'} n) smoothed speed _V'n with
And the calculated coordinate value P at time T = n−1 that has already been obtained
From _'n-1 Tokyo, it is possible to obtain the calculated coordinate values _P'n at time T = n.

In the above arithmetic processing, step S40
Realizes the function of the speed calculation means 10 for calculating the speed, which is the amount of change in position per unit time, based on a plurality of coordinate values generated by the control unit 3. Also, steps S41 to S
49 and routines S50 and S51 are speed smoothing means 11 for smoothing the change in the moving speed of the three-dimensional coordinate designating section 1 based on the plurality of speed values calculated by the speed calculating means 10 by calculation. Has achieved the function of.
Further, step S52 is a coordinate value calculation means 1 for calculating a new coordinate value based on the speed calculated by the speed smoothing means 11.
It has achieved two functions.

In this method, the velocity, that is, the movement of the user's hand itself is smoothed, so that the three-dimensional coordinate values can be obtained more smoothly than in the above method.

Next, the operation of the three-dimensional coordinate input device according to claims 3, 4, 8 and 10 will be described. Here, it is assumed that the smoothness of the three-dimensional coordinate value is specified, and only the operation of this part will be described. FIG. 8A is a block diagram showing the configuration of the smoothness input device 18 of FIG. Here, the smoothness means the cutoff frequency ω _c of the low pass filter.
Determined by Further, the smoothness shall be changed and instructed at any time according to the convenience of the user.

As shown in FIG. 8A, the smoothness input device 18 which is the smoothness designating means 6 comprises a control section 41, a slider display means 42, a display device 43 and a mouse input device 44. . The control unit 41 is a device that controls the input and output of the smoothness input device 18. The slider display means 42 displays the value of the cutoff frequency of the low-pass filter based on the output of the control unit 41 and the slider which is interlocked with the value.
3 is displayed. The mouse input device 44 is an input device for the user to instruct a change (high or low) of the cutoff frequency, and the signal is given to the control unit 41. FIG. 8B is a screen display example of the display device 43. A slider 46, a slider cursor 47, and a cutoff frequency are displayed on the display screen 45.

The smoothness input device 18 thus configured
The procedure for changing the cutoff frequency in step 1 will be described with reference to the flowchart in FIG. Control unit 4 of FIG.
1 reads out the value of the cutoff frequency of the low-pass filter stored in the storage device 15 in step S61 of FIG. Then, the value is given to the slider display means 42.
In step S62, the slider display means 42 calculates the position of the slider cursor 47 according to the cutoff frequency. Then, in step S63, the slider display means 42 displays the cutoff frequency and the slider cursor 47 in the slider 46 on the display device 43.

When the user changes the cutoff frequency, the display screen 4 of the display device 43 is displayed in step S64.
While looking at 5, the mouse input device 44 is operated. Then, the slider cursor 47 moves, and the movement data is output to the control unit 41. In step S65, the control unit 41
Calculates a new cutoff frequency corresponding to the amount of movement of the slider cursor 47. Then, in the next step S66, the control unit 41 outputs the calculated new cutoff frequency to the central processing unit 17 of FIG. Then, the central processing unit 17 recalculates the transfer function of the low-pass filter according to the output new cutoff frequency.

Here, the processing of steps S64 to S66 is as follows.
Even when the position smoothing means 5 is operating, the function of the filter characteristic designating means 7 for freely designating and changing the smoothness degree is achieved by designating the pass band of the digital filter (low-pass filter 20). are doing.

For example, in the case of the low-pass filter represented by the equation (1), when the cutoff frequency is ω _c and the coordinate value measurement interval is Δt (seconds), the coefficient is as shown in the following equation (3). Become.

[Equation 2]

According to the above equation, the central processing unit 17 is the arithmetic unit 1
6, the arithmetic unit 16 calculates the coefficient of the low-pass filter corresponding to the new cutoff frequency. The calculation result is stored in a predetermined location of the storage device 15. After this arithmetic processing is completed, smoothing processing is performed according to the new cutoff frequency. That is, coordinate value measurement interval Δt
Is set to, for example, 1 millisecond, and the cutoff frequency ω _{c is set} to 1 k radian / second, the coefficient is expressed by the following equation (4).

The cutoff frequency ω _c is lowered to 100
When radians / second is used, the coefficient is as in the following expression (5).

Next, the operation of the three-dimensional coordinate input device according to the fifth aspect will be described. Here, the threshold designation device 19 in the error determination of the three-dimensional coordinate value will be described.
FIG. 10A is a block diagram showing the configuration of the threshold designating device 19 of FIG. Threshold designating device 1 which is threshold designating means 9
Reference numeral 9 denotes a control unit 71, a slider display means 72, a display device 7.
3. The mouse input device 74 is included. Control unit 7
Reference numeral 1 controls the input / output of the threshold value specifying device 19.
The slider display means 72 displays the threshold value q and a slider linked thereto on the display device 73. The mouse input device 74 is an input device for the user to instruct a threshold value.

FIG. 10B shows the display screen 7 of the display device 73.
5, the threshold value and the slider cursor 76 are displayed on the display screen 75. FIG. 11 is a flowchart showing the procedure for changing the threshold value q. The control unit 71 reads the threshold value q stored in the storage device 15 of FIG. 3 and outputs it to the slider display unit 72. The slider display means calculates the position of the slider cursor 76 according to the threshold value q, and displays the threshold value q and the slider cursor 76 on the display device 73. The user moves the slider cursor 76 on the display screen 75 using the mouse input device 74 to change the threshold value. The movement data of the slider cursor 76 is given to the control unit 71. Then, the control unit 71 calculates a new threshold value q'corresponding to the movement amount of the slider cursor 76. The new threshold value q'is stored in a predetermined location of the storage device 15 through the central processing unit 17 of FIG.

FIG. 12 is a flow chart showing the error comparison procedure of three-dimensional coordinate values. The central processing unit 17 of FIG.
In step S71, the arithmetic unit 16 determines the three-dimensional calculated coordinate value P.
_'N is calculated and compared to the measured coordinate values P _n and the calculated coordinate values of the three-dimensional input from the next step S72 the control unit 3 _P'n. Therefore obtaining the difference value p of the three-dimensional coordinate measurement step S72 P _n and the three-dimensional coordinate calculation value _P'n.

In the next step S73, the threshold designating device 1
The threshold value q set by 9 is read from the storage device 15. Then, in step S74, the process proceeds to step S75 if the set threshold value q is not less than the difference value d, and outputs the newly calculated three-dimensional calculation coordinates _P'n as the correct 3-dimensional coordinate values. If the difference value d is larger than the threshold value q stored in the storage device 15, step S76.
Then, the three-dimensional measurement coordinate value P _n obtained by measurement is output.

The processing in steps S72 to S74 is as follows.
The difference value between the coordinate value p measured by the three-dimensional coordinate measuring unit 2 and the coordinate value p ′ calculated by the position smoothing means 5 is compared with a predetermined threshold value, and the difference value is larger than a preset threshold value. In this case, the function of the error comparison means 8 that specifies the measured coordinate value p as the input coordinate value instead of the calculated coordinate value p ′ is achieved.

By such error comparison processing, the case where the user intentionally moves the three-dimensional coordinate designating section 1 by hand to change the three-dimensional coordinate value and the case where the user unconsciously generates a three-dimensional coordinate It becomes possible to clearly distinguish the change in the coordinate value.

In the three-dimensional coordinate input device of this embodiment, all the three-dimensional coordinate measurement values are processed using the low pass filter as a smoothing method, but other smoothing methods can be used. . One example is the use of parametrically expressed curves. When the B-spline curve is used as the parametric curve, the degree of smoothing is controlled by using the measured value of the three-dimensional coordinates and the speed obtained from the measured value as the control amount. Thus, the order of the B-spline curve and the knot vector can be used as the smoothing parameters. By doing so, it is possible to calculate a three-dimensional coordinate value or a three-dimensional velocity with arbitrary smoothness (“Expression method of free-form curve”, Sadaji Takamura, Hiroshi Toriya, Nikkei CG, June 1989, 162-168. See page).

[0062]

As described above, according to the invention of claim 1 of the present application, by providing the position smoothing means, it is possible to smooth changes in a plurality of measured three-dimensional coordinate values. For this reason, it is possible to eliminate the influence of camera shake or the like of the operator who operates the three-dimensional coordinate instruction unit.

According to the second and ninth aspects of the present invention, by using the digital filter as the smoothing means,
It is possible to arbitrarily reduce the influence of relatively high frequency components such as hand shake and camera shake according to the situation of occurrence.

According to the invention of claims 3, 4, 8 and 10, the smoothing index designating means for designating the smoothing degree of the smoothing means or the filter characteristic designating for the characteristic of the digital filter. By providing the designating means, the smoothing degree can be freely designated and changed even when the three-dimensional coordinate input device is in use, and the influence of camera shake or the like can be dealt with more flexibly.

According to the invention of claim 5 of the present application, by providing the error comparison means, when the measured coordinate value is larger than the value designated in advance, the measured coordinate value is measured, not the calculated coordinate value. Coordinate values can be used as input coordinate values. In this case, it becomes possible for the user to deal with inputting a new three-dimensional coordinate value sequence.

Further, according to the invention of claim 6 of the present application, by providing the threshold designating means, the comparison value required by the error comparing means can be set or changed at any time. Therefore, it is possible to more flexibly deal with the coordinate value series intended by the user.

According to the invention of claim 7 of the present application, the speed, that is, the movement of the user's hand itself can be smoothed by providing the speed smoothing means. Therefore, 3 according to claim 1
A smoother three-dimensional coordinate value can be obtained with the three-dimensional coordinate input device.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a three-dimensional coordinate input device according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a three-dimensional coordinate input device according to a second embodiment of the present invention.

FIG. 3 is a system configuration diagram of a three-dimensional coordinate input device according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration example of a low-pass filter used in this embodiment.

FIG. 6 is a signal processing procedure showing a three-dimensional coordinate value smoothing method (No. 1) in the present embodiment.

FIG. 7 is a signal processing procedure showing a three-dimensional coordinate value smoothing method (No. 2) in the present embodiment.

FIG. 8 is a configuration diagram of a smoothness input device included in the three-dimensional coordinate input device according to the present embodiment.

FIG. 9 is an explanatory diagram of a smoothness input operation procedure in the smoothness input device of the present embodiment.

FIG. 10 is a configuration diagram of a threshold designation device included in the three-dimensional coordinate input device according to the present embodiment.

FIG. 11 is a signal processing procedure showing the operating principle of the threshold designating device included in the three-dimensional coordinate input device of the present embodiment.

FIG. 12 is an explanatory diagram of a threshold value specifying operation procedure in the threshold value specifying device of the present embodiment.

FIG. 13 is a configuration diagram of a three-dimensional coordinate input device in a conventional example.

[Explanation of symbols]

 1 3 dimensional coordinate instructing section 2 3 dimensional coordinate measuring section 3, 41, 71 control section 4, 4a, 4b arithmetic control section 5 position smoothing means 6, 13 smoothing index designating means 7, 14 filter characteristic designating means 8 error comparison Means 9 Threshold Designating Means 10 Velocity Calculating Means 11 Velocity Smoothing Means 12 Coordinate Value Calculating Means 15 Storage Devices 16 Computing Devices 17 Central Processing Units 18 Smoothness Input Devices 19 Threshold Designating Devices 20 Low Pass Filters 20A First Partial Filters 20B Second partial filter 20a Input terminal 20b Output terminal 21,25,26 Delay circuit 22,23,27,28,29,30 Multiplier 24,31 Inversion circuit 42,72 Slider display means 43,73 Display device 44,74 Mouse input device 45,75 Display screen 46 Slider 47,76 Slider cursor

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[Procedure amendment]

[Submission date] March 3, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a functional block diagram of a three-dimensional coordinate input device according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a three-dimensional coordinate input device according to a second embodiment of the present invention.

FIG. 3 is a system configuration diagram of a three-dimensional coordinate input device according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration example of a low-pass filter used in this embodiment.

FIG. 5 is a concrete example of a low-pass filter used in this embodiment.
3 is a circuit diagram showing a typical configuration example. FIG.

FIG. 6 is a signal processing procedure showing a three-dimensional coordinate value smoothing method (No. 1) in the present embodiment.

FIG. 7 is a signal processing procedure showing a three-dimensional coordinate value smoothing method (No. 2) in the present embodiment.

FIG. 8 is a configuration diagram of a smoothness input device included in the three-dimensional coordinate input device according to the present embodiment.

FIG. 9 is an explanatory diagram of a smoothness input operation procedure in the smoothness input device of the present embodiment.

FIG. 10 is a configuration diagram of a threshold designation device included in the three-dimensional coordinate input device according to the present embodiment.

FIG. 11 is a signal processing procedure showing the operating principle of the threshold designating device included in the three-dimensional coordinate input device of the present embodiment.

FIG. 12 is an explanatory diagram of a threshold value specifying operation procedure in the threshold value specifying device of the present embodiment.

FIG. 13 is a configuration diagram of a three-dimensional coordinate input device in a conventional example.

[Explanation of Codes] 1 three-dimensional coordinate instructing section 2 three-dimensional coordinate measuring section 3, 41, 71 control section 4, 4a, 4b arithmetic control section 5 position smoothing means 6, 13 smoothing index designating means 7, 14 filter characteristics Designating means 8 Error comparing means 9 Threshold designating means 10 Speed calculating means 11 Speed smoothing means 12 Coordinate value calculating means 15 Storage device 16 Computing device 17 Central processing unit 18 Smoothness input device 19 Threshold designating device 20 Low pass filter 20A No. 1 partial filter 20B 2nd partial filter 20a input terminal 20b output terminal 21,25,26 delay circuit 22,23,27,28,29,30 multiplier 24,31 inversion circuit 42,72 slider display means 43,73 Display device 44,74 Mouse input device 45,75 Display screen 46 Slider 47,76 Slider cursor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06F 17/50 // G06T 7/00 G06F 15/62 415

Claims (10)

[Claims] 1. A three-dimensional coordinate instructing section for instructing an arbitrary three-dimensional position, a three-dimensional coordinate measuring section for measuring the position of the three-dimensional coordinate instructing section, and coordinates from a measurement result of the three-dimensional coordinate measuring section. A three-dimensional coordinate input device comprising: a control unit for generating a value; and a position smoothing operation for smoothing a change in coordinate value based on a plurality of coordinate values generated by the control unit. A three-dimensional coordinate input device having an arithmetic control unit including means. 2. The three-dimensional coordinate system according to claim 1, wherein the position smoothing means is a digital filter that inputs the measured three-dimensional coordinate value and outputs the smoothed coordinate value. Input device. 3. The position smoothing means comprises filter characteristic designating means for freely designating and changing the smoothness degree by designating a pass band of the digital filter even during operation. The three-dimensional coordinate input device according to claim 2, wherein the three-dimensional coordinate input device is provided. 4. The position smoothing means comprises smoothing index designating means for freely designating and changing the smoothness degree of coordinate values even during operation. The three-dimensional coordinate input device according to 1. 5. The calculation control unit compares the difference value between the coordinate value p measured by the three-dimensional coordinate measuring unit and the coordinate value p ′ calculated by the position smoothing unit with a predetermined threshold value, When the difference value is larger than a threshold value specified in advance, the calculated coordinate value p ′ is not
An error comparison means for designating the measured coordinate value p as an input coordinate value is provided.
[3] The three-dimensional coordinate input device according to any one of [4] to [4]. 6. The arithmetic control unit is provided with a threshold designating unit for freely selecting and changing the threshold of the error comparing unit even during measurement of three-dimensional coordinates. The three-dimensional coordinate input device according to item 5. 7. A three-dimensional coordinate instructing unit for instructing an arbitrary three-dimensional position, a three-dimensional coordinate measuring unit for measuring the position of the three-dimensional coordinate instructing unit, and coordinates from a measurement result of the three-dimensional coordinate measuring unit. In a three-dimensional coordinate input device including a control unit that generates a value, a speed calculation unit that calculates a speed, which is a change amount of a position per unit time, based on a plurality of coordinate values generated by the control unit. And a speed smoothing means for smoothing a change in the moving speed of the three-dimensional coordinate designating section based on a plurality of speed values calculated by the speed calculating means so as to be smooth, and the speed smoothing means. A three-dimensional coordinate input device, comprising: a calculation control unit including a coordinate value calculation unit that calculates a new coordinate value based on the speed calculated in step 3. 8. The speed smoothing means is provided with a smoothing index designating means for freely designating and changing a smoothness degree of a speed value even when the speed smoothing means is in operation. The three-dimensional coordinate input device according to claim 7. 9. The speed smoothing means is a digital filter which receives the three-dimensional speed value calculated by the speed calculating means and outputs the output as a smoothed speed value. Item 3. The three-dimensional coordinate input device according to item 7. 10. The velocity smoothing means comprises filter characteristic designating means for freely designating and changing a smoothness degree by designating a pass band of the digital filter even during operation. The three-dimensional coordinate input device according to claim 9, wherein the three-dimensional coordinate input device is provided.