JPH07244147A - Position measuring apparatus and portable information terminal - Google Patents

Abstract

PURPOSE:To compute the position of an object to be measured by a method wherein, on the basis of the difference in the time in which a transmitted criterion signal reaches every receiver for a measuring device, the difference in a distance between every receiver and a transmitter is found and positional information on every receiver is added to the difference. CONSTITUTION:A plurality of measuring devices M0 to Mn are connected to an object TG to be measured, and the measuring devices M0 to Mn are provided respectively with receivers R0 to Rn. The individual measuring devices are connected to a measuring-device processing part PU as a computation means. A criterion signal which is transmitted from the target TG reaches the receivers R0 to Rn. The arrival time T0 to the receiver R0 as a criterion is used as a criterion and the arrival time Tn to the other eceivers is described as a time difference from the T0. Then, on the basis of every time difference T0 and of a transmission velocity V at which the criterion signal is transmitted in a space, a distance difference Ln between the target TG and every receiver is found. By using distance differences L1 to Ln obtained in this manner and positional information on the receivers R0 to Rn, the position (X, Y, Z) of the target TG is found.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position measuring device capable of measuring the position of an object to be measured without knowing the transmission time of a signal transmitted from the object to be measured, and a pen type input device. Without knowing the transmission time of the signal to be transmitted,
The present invention relates to a portable information terminal capable of measuring the position of a pen.

[0002]

2. Description of the Related Art A conventional two-dimensional or three-dimensional position measuring device using ultrasonic waves, light or the like measures the distance between a measured object having a transmitter and a measuring device having a plurality of receivers. In the case of calculation, the transmission time difference until the signal such as light output from the transmitter reaches each receiver is calculated, and the distance between the two is calculated based on the obtained transmission time difference.

[0003]

However, the above-mentioned conventional position measuring device directly uses the transmission time difference between the transmitter and the receiver in order to calculate the distance between the object to be measured and the measuring device. Therefore, it is necessary to transmit the reference time between the object to be measured and the measuring device, which makes it difficult to realize wireless communication.

The position measuring device and the portable information terminal of the present invention have been made in view of such a problem, and the purpose thereof is to use the transmission time of the reference signal transmitted from the transmitter. It is another object of the present invention to provide a position measuring device and a portable information terminal capable of measuring three-dimensional position information and performing an input operation such as a position instruction without the need.

[0005]

In order to achieve the above object, the position measuring apparatus of the present invention includes an object to be measured equipped with a transmitter that outputs a reference signal, and each of the objects to be measured corresponds to the object to be measured. Measuring means having a plurality of receivers for receiving reference signals from the object to be measured, which are provided at positions, a time difference in which the reference signals from the object to be measured reach the plurality of receivers, and each receiver And a calculating means for calculating the positional relationship between the measuring means and the object to be measured based on the positional relationship.

Further, the portable information terminal of the present invention is provided with a pen type input device having a transmitter for outputting a reference signal at its tip, and the pen type input device is provided at a position corresponding to each of the pen type input devices. A head-mounted display device having a plurality of receivers for receiving a reference signal from a measurement object, a time difference when the reference signal reaches the plurality of receivers, and a positional relationship between the receivers, A calculation means for calculating a positional relationship between the head-mounted display device and the pen-type input device is provided.

[0007]

That is, the position measuring device of the present invention determines the arrival time difference between the receivers from the time when the reference signal transmitted from the transmitter reaches each receiver of the measuring device, and determines the arrival time difference between the receivers from this time difference. The difference in the distance between the transmitters is obtained, and the position information of each receiver is added to this to calculate the position of the measured object.

In the portable information terminal of the present invention, the arrival time difference between each reception is obtained from the time when the reference signal transmitted from the transmitter mounted on the pen tip reaches each receiver of the measuring device, The difference in the distance between each receiver and the transmitter is obtained from this time difference, and the position information of each receiver is added to this to calculate the position of the pen tip.

[0009]

1 is a block diagram showing the configuration of a first embodiment of the present invention. In the figure, a plurality of measuring devices M0 are attached to a measured object (target) TG equipped with a transmitter (not shown).
To Mn are connected, and these measuring devices M0 to Mn are connected.
Respectively comprises receivers R0-Rn. Further, each measuring device is connected to a measuring device processing unit PU as a calculating means.

FIG. 2 is a diagram showing an example of the positional relationship between the transceivers in the first embodiment. In the figure, the target TG is placed at the position (x, y, z). The reference receiver R0 is at (0,0,0) (origin), and the other receivers R1, R2, R3 are R1: (X, 0, 0) R2: (2X, 0, 0) R3, respectively. : (0,2Y, 0) is installed.

It is desirable that the number of receivers is four or more, and up to four receivers must be arranged at positions other than line and point objects. Such a position may be used. When the positional relationship of the receiver has a target axis or a target point, there is a blind spot where measurement is impossible.
Of course, more than the required number of receivers may be prepared. In this case, by changing the combination of receivers or integrating a plurality of processing results, it is possible to improve the accuracy of the measurement value and extend the measurement range.

The measurement operation will be described below. Reference signals such as light and ultrasonic waves transmitted from the target TG are received by the receivers R0 to R0.
Reach Rn. Arrival time T at the reference receiver R0
The arrival time Tn at each of the other receivers is set to T0
Described as the time difference from. Then, each time difference T
n and the transmission velocity v of the reference signal transmitted in space, TG
The distance difference Ln from each receiver to Ln is calculated as Ln = Tnv. Thus obtained distance differences L1 to Ln and R0 to
Using the position information of Rn, the position (x,
y, z) can be obtained. The calculation formula in the case of this embodiment is shown below.

[0013]

[Equation 1]

[0014]

[Equation 2]

Here, the absolute distance L0 is not used, but only the difference in time to reach each receiver (= the difference in distance between the target TG and each receiver) is used. Therefore, it is not necessary to transmit the time when the reference signal is transmitted from the target TG, and the target TG and the measuring device can be easily separated.

FIG. 3 is a diagram for explaining the method for measuring the arrival time difference in this embodiment, which is an example using a pulse waveform as a reference signal. In the same figure, the arrival times T1 to Tn of the other receivers are calculated with the time when the reference receiver R0 receives an input as the reference time T0.

In FIG. 4, a periodic waveform is used as a reference signal, and the arrival time difference is measured by the obtained phase information. Here, by comparing the phase of the signal input to the reference receiver R0 and the phase of the signal input to the other receivers R1 to Rn, the arrival time differences T1 to Tn between the receivers are determined. You can ask.

Further, the reference signal is not a simple pulse or sine waveform but a complicated waveform, so that it can be made strong against noise from the outside world. Further, by modulating the reference signal, it becomes possible to measure the position and simultaneously transmit other information such as the state of the target TG.

FIG. 5 is a diagram showing a second embodiment of the present invention, which is an application example to a portable information terminal in which a pen type input device and an HMD (head mounted display) are combined.
The portable information terminal of the second embodiment is a pen type input device PN and H.
It consists of MD. The pen type input device PN is a pen tip P
The pen tip PT has a transmitter LD and a pen down detection switch S1 attached thereto. The push button switch S2 is attached to the pen body.
And a sensor SN that detects the acceleration and movement speed of the pen,
A pen information processing device PPU that processes pen information is attached.

The HMD is a pair of transmissive display devices L.
CD and a pair of eyeglass-like frame parts F surrounding them
It is composed of R and a main information processing unit PPU connecting each frame. Then, in each frame FR, a plurality of receivers R0
~ R7 are arranged at positions that are not point-symmetrical or line-symmetrical with respect to the transmitter LD.

Here, DR is the movement path of the pen, CU is the pen cursor displayed on the display device LCD, DS is the movement path of the pen displayed on the display device LCD, and EY is the operator's eyes.

The reference wave transmitted from the transmitter LD attached to the tip of the pen type input device PN enters the receivers R0 to Rn attached to the frame FR, and the receiver R0.
~ Rn outputs corresponding signals. Main information processing device PP
U calculates the relative position between the pen-type input device PN and the frame FR based on these outputs. The calculation method is the same as in the first embodiment. And, in advance, the eye EY and the frame FR
The position of the pen tip PT as seen through the display LCD can be calculated by measuring the positional relationship of the above, and the pen cursor CU can be displayed on the corresponding display device LCD. From the operator's point of view, the pen cursor CU appears to overlap the pen tip PT of the actual pen-type input device PN seen through the display device LCD. By doing this,
The pen movement locus DR as a virtual drawing is displayed on the display device LCD as if the ink were coming out from the pen tip.
Can be seen as S.

Normally, when a character or figure is drawn using the pen type input device PN, the pen tip PT is seen with the eyes EY. Therefore, the transmitter LD mounted on the pen tip RT can be directly seen from the receivers R0 to Rn arranged on the frame FR near the eyes. Frame FR and eye E
Since the position is slightly different from Y, it is possible that the transmitter may disappear from a part of the receiver due to obstacles such as fingers, but by arranging the receiver all around the frame FR, , It is always possible to see the transmitter from more than three receivers (not line or point targets).

Furthermore, since the pen-down detection switch S1 and the push button switch S2 are built in the pen-type input device PN, the output from the transmitter LD can be modulated and transmitted according to the switch information. by this,
Besides measuring the position, other information can also be conveyed. Further, the pen-type input device PN has a sensor SN for measuring velocity and acceleration to calculate the moving distance of the pen, which is transmitted from the transmitter LD, and integrated with the result obtained by the position measuring device, thereby making it more accurate. It is possible to measure various positions.

Further, the sensor SN and the switches S1 and S2
It is also possible to recognize the drawn characters and figures by processing the signal from. Recognition is performed by the main information processing unit PPU in the pen.
Alternatively, the result may be transmitted from the transmitter LD or may be performed by the main information processing unit PPU mounted in the frame FR.

[0026]

As described above, according to the invention of claim 1,
Since the distance between the transmitter and each receiver is not directly calculated, but only the difference between the distance between the transmitter and each receiver is used, it is not necessary to calculate the transmission time of the reference signal from the transmitter. Further, this makes it possible to easily make the transmitter and the receiver wireless.

According to the invention described in claim 2, in addition to the effect of claim 1, the circuit configuration can be further simplified. According to the invention of claim 3, in addition to the effect of claim 1, high distance resolution can be achieved.

Further, according to the invention described in claim 4, in addition to the effect of claim 1, it becomes stronger against noise from the outside and more accurate measurement can be performed. According to the invention described in claim 5, in addition to the effects of claims 1 to 4, it is possible to measure the position and transmit other information.

According to the invention described in claim 6, since the distance between the transmitter and each receiver is not directly obtained, only the difference between the distance between the transmitter and each receiver is used. There is no need to find the time when the reference signal is sent from the instrument. Also,
As a result, the transmitter and the receiver can be easily made wireless.

According to the invention described in claim 7, in addition to the effect of claim 6, it becomes possible to simultaneously transmit other information while measuring the position. According to the invention of claim 8, in addition to the effect of claim 6,
More accurate position measurement becomes possible. According to the invention of claim 9, in addition to the effect of claim 6, it is possible to recognize drawn characters and figures.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between transceivers.

FIG. 3 is a diagram for explaining a method of measuring the arrival time difference using a pulse signal.

FIG. 4 is a diagram in which a periodic waveform is used as a reference signal and the arrival time difference is measured by the obtained phase information.

FIG. 5 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

TG ... Object to be measured, R0 to Rn ... Receiving unit, PU ... Measuring device processing unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeru Oikawa 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Noboru Sonehara 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (9)

[Claims] 1. An object to be measured having a transmitter for outputting a reference signal, and a plurality of receivers each provided at a position corresponding to the object to be measured and receiving the reference signal from the object to be measured. Based on the measuring means having, the time difference when the reference signal from the measured object reaches the plurality of receivers, and the positional relationship between the receivers,
A position measuring device comprising: a measuring unit that calculates a positional relationship between the measuring unit and the measured object. 2. The reference signal is a pulse signal, and the calculating means uses the time when the pulse signal arrives at a reference receiver among the plurality of receivers as a reference time to send to another receiver. The position measuring device according to claim 1, wherein each time difference is obtained by calculating the arrival time of the pulse signal. 3. The reference signal is a periodic signal, and the calculating means calculates a phase when the periodic signal reaches a reference receiver of the plurality of receivers and the periodic signal. 2. The position measuring device according to claim 1, wherein each time difference is obtained by comparing with a phase when reaching another receiver. 4. The position measuring device according to claim 1, wherein the reference signal has a shape other than a pulse or a periodic waveform. 5. The position measuring device according to claim 1, wherein the reference signal is modulated and transmitted. 6. A pen-type input device having a transmitter for outputting a reference signal at a tip end thereof, each of which is provided at a position corresponding to the pen-type input device,
A head-mounted display device having a plurality of receivers for receiving a reference signal from the measured object, and a time difference in which the reference signal reaches the plurality of receivers,
A portable information terminal comprising: a calculating unit that calculates a positional relationship between the head-mounted display device and the pen-type input device based on a positional relationship between the receivers. 7. The portable information terminal according to claim 6, wherein the pen-type input device includes a switch for modulating the reference signal. 8. The portable information terminal according to claim 6, wherein the pen-type input device includes a sensor for measuring a moving speed or a moving acceleration of a pen tip portion. 9. The pen-type input device comprises a switch for modulating the reference signal, and a sensor for measuring a moving speed or a moving acceleration of a pen tip portion. The portable information terminal described.