JPS61243308A - Three-dimensional position measuring instrument - Google Patents

Abstract

PURPOSE:To reduce the weight of a three-dimensional position measuring instrument without damaging a measuring accuracy by providing a measuring rod with an ultrasonic generator, arranging an ultrasonic receiver for receiving the output signal of the generator, and calculating the position to be measured on the basis of the signal received by the receiver. CONSTITUTION:A measuring rod 3 for specifying a point whose position is to be measured is provided with ultrasonic generators 4 and 5 and a plurality of ultrasonic receivers 11-16 for receiving a signal from the ultrasonic generators 4 and 5 are arranged above a measuring table 1. By continuously monitoring the quantity of displacement of the measuring rod 3 relative to a reference position by an arithmetic unit 10 based on a signal from the ultrasonic receivers 11-16, the distances between the ultrasonic generators 4 and 5 and the ultrasonic receivers 11-16 are calculated, whereby the three- dimensional position of the point to be measured is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a three-dimensional position measuring device that measures the three-dimensional position of an object by specifying each part of the object.

[Prior Art] A conventional three-dimensional position measuring device consists of a multi-joint link mechanism with one end fixed to a measuring table, and when it comes into contact with each part of the object to be measured placed on the measuring table, each joint The three-dimensional position of the point to be measured is determined mechanically by measuring the amount of displacement of It is also known to measure

[Problems to be Solved by the Invention] However, since the above-mentioned conventional devices have mechanically movable parts, the mechanical rigidity and mechanical precision of the constituent parts are required to be high. There was a problem in that the device itself was large-scale and the field of use was limited.

This invention was made to solve this problem, and only specifies each point of the object to be measured, that is, the point to be measured, with the tip of the measuring rod, and does not have any other moving parts or positioning parts. The object of the present invention is to obtain an extremely lightweight and compact three-dimensional position measuring device that can calculate the three-dimensional position without compromising accuracy.

[-Means for solving the problem] The three-dimensional position measuring device according to the present invention includes an ultrasonic oscillator provided on a measuring rod for specifying a point to be measured, and an ultrasonic oscillator that receives a signal from the ultrasonic oscillator. A plurality of ultrasonic receivers are arranged above the measurement table, and an arithmetic device is provided for calculating the three-dimensional position of the point to be measured based on the signals obtained by the ultrasonic receivers.

[Operation] In this invention, the calculation device calculates the distance between the ultrasonic oscillator and the ultrasonic receiver by constantly monitoring the amount of movement of the measuring rod with respect to the reference position based on the signal from the ultrasonic receiver. This determines the three-dimensional position of the non-measurement point.

〔Example] The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partial side block diagram showing an embodiment of a three-dimensional position measuring device according to the present invention. In the figure, 1 is a measurement table, 2 is an object to be measured placed on the measurement table 1, 3 is a pen-shaped measuring stick for specifying each point on the object to be measured 2, that is, the point to be measured; 4. 5 is an ultrasonic oscillator (hereinafter simply referred to as an oscillator) provided integrally at the tip and center of the measuring rod 3; 6 is a push button switch provided on the measuring rod 3 to output a signal as appropriate; 7 is a measuring device A flexible signal line 8 connected to the rod 3 is a microcomputer (hereinafter simply referred to as a microcomputer) connected to the measuring rod 3 via a signal line 7. 11 to 16 are a plurality of ultrasonic receivers (hereinafter simply referred to as receivers) positioned above the measurement table 1, and the receivers 11 to 3 detect and receive ultrasonic signals from the oscillator 4. The devices 14 to 16 are adapted to detect ultrasonic signals from the oscillator 5.

21 to 26 are signal amplification circuits for amplifying the signals 11a to 16a received by the receivers 11 to 16, respectively; 31 to 36 are provided corresponding to each of the signal amplification circuits 21 to 26; A phase difference measurement circuit inputs signals 21a to 26a, 40 an ultrasonic oscillation circuit for driving the oscillator 4 (hereinafter simply referred to as an oscillation circuit), and 50 an ultrasonic oscillation circuit for driving the oscillator 5 (hereinafter simply referred to as an oscillation circuit). ), and each oscillation circuit 40 . 50 and the oscillator 4.5 are connected to the signal line 7a, ? b is formed integrally with the signal line 7 described above. Moreover, the output signal 4 of the oscillation circuit 40
0a is also connected to other input terminals of the phase difference measurement circuits 31 to 33, and each amplified reception signal 21a to 2
It is designed to be compared with 3a. On the other hand, the oscillation circuit 5
The output signal 50a of 0 is connected to the other input terminals of the phase difference measuring circuits 34 to 36, and each amplified received signal 24a is connected to the other input terminals of the phase difference measurement circuits 34 to 36.
The phase difference outputs 31a to 36a of the zero phase difference measurement circuits 31 to 36, which are compared with the zero phase difference measuring circuits 31 to 26a, are input to the microcomputer 8. These signal amplification circuits 21 to 26
, phase difference measurement circuits 31 to 36 and oscillation circuit 40.50
constitutes an arithmetic unit 10 together with the microcomputer 8.

Next, the specific operation will be explained with reference to the waveform diagrams in FIGS. 2(a) and 2(b).

In this embodiment, in order to accurately measure the distance between the oscillator 4 and the receivers 11 to 13, and the distance between the oscillator 5 and the receivers 14 to 16, the signal waveforms of these oscillators and the signal waveforms of the receivers are The distance between the oscillator 4.5 and the receivers 11 to 16 is calculated by constantly monitoring the phase relationship between the two. First, the measurer holds the measuring stick 3 in his hand and measures the object 2 on the measuring table 1.
A point to be measured, for example, point P, is specified with the tip of the measuring rod 3. In this state, the oscillators 4.5 are driven by oscillation circuits 40 and 50, respectively, and the oscillation frequency of the oscillation circuit 40 is, for example, 40Kflz, and the oscillation frequency of the oscillation circuit 50 is 26Kflz. It is like that.

Therefore, each oscillator 4.5 has a frequency of 40 KHz.

This means that it emits 26KHz ultrasonic waves.

Each receiver 11-13 and 14-16 each has 4QK
) Iz and 26 Hz frequency, each oscillator 4
Or, the signals from only 5 are set as received signals 1.1a to 16a, and are amplified by signal amplification circuits 21 to 26. Now, if point P is used as a reference point, other measured points are measured using this point P as the origin, but it is possible to set a desired origin on the measurement table as appropriate.

6, each phase difference signal 31a to 36 at that time
a is applied to the microcomputer 8, where a predetermined calculation is performed and the three-dimensional position of the point P is stored in a memory (not shown) within the microcomputer 8.

Of course, since the information regarding the position of each oscillator 4.5 with respect to the measuring rod 3 is input into the microcomputer 8 in advance, the measuring rod 3
Even if the hand holding the object rotates around point P, the calculated position of point P does not change.

Next, assume that the measuring rod 3 is moved to another point to be measured. For example, if the distance between the oscillator 4 that emits a 40Kth ultrasonic wave and the receiver 11 is 1.5 times the wavelength of the 40KHz sound wave, or 12.75 mm, then the output signal of the oscillator 4, that is, the oscillation circuit 40 Output signal 40a
The phase relationship between the received signal 11a of the receiver 11 and the received signal 11a of the receiver 11 is shown in FIG.
, ) as shown in FIG. 2(b). Figure 2(a)
As shown, before the measuring rod 3 is moved, the peak W + ~W 3 of the output signal 40a and the peak Ill
11) are coincident with each other with zero phase difference, after the measuring rod 3 moves away from the distance equivalent to 1.5 times the wavelength as described above, the received signal 11a becomes as shown in FIG. 2(b).
It can be seen that a phase delay of 1.5 times the wavelength occurs compared to the output signal 40a. Arithmetic device 10 always receives received signal 1
Since the received signal 11a is compared with the output signals 40a and 50a and the phase difference between them is monitored.
-16a can be recognized from time to time. Therefore, Fig. 2 (
It is recognized that the state b) is not a half-wavelength delay from the state shown in FIG. 2(a), but a phase delay of 1.5 times the wavelength.

In this way, the received signals 11a~ from each receiver 11~16
The microcomputer 8 in the arithmetic unit 10 uses the phase difference signals 31a to 36a based on the oscillator 4.5 and the receiver 1
The distance is calculated from the distance change from 1 to 16, and the three-dimensional position of the measured point after movement is calculated and determined. Then, as described above, the position of the next point to be measured is stored in the memory within the microcomputer 8 by operating the push button switch.

The fixed points to be translated of the object to be measured 2 stored one after another in this way can be changed or displayed as appropriate by using other push buttons (not shown) or an input device connected to the microcomputer 8.

In the above embodiment, the oscillators 4.5 are attached to two locations on the measuring rod 3, and three receivers 11 to 13 and 14 to 46 are provided corresponding to each oscillator 4.5 to determine the phase. Although the detection was performed, it goes without saying that the overall configuration and calculation contents can be simplified by providing only one oscillator at the tip of the measuring rod 3 and configuring only three receivers.

Alternatively, if high accuracy is not required, the phase difference measurement circuits 31 to 36 may be omitted, and the oscillator 4.5 may emit the signal at regular time intervals, as is used for distance measurement using normal ultrasonic waves. Alternatively, the distance between the receivers 11 to 16 may be calculated from the time required for the ultrasonic pulse to reach the receivers 11 to 16.

[Effects of the Invention] As explained above, the present invention has a configuration in which a measuring rod is provided with an ultrasonic oscillator, an ultrasonic receiver is provided to receive the output signal, and a point to be measured is calculated based on the received signal. Therefore, it is possible to provide an extremely lightweight and compact three-dimensional position measuring device without compromising measurement accuracy.

[Brief explanation of drawings]

FIG. 1 is a partial side block diagram showing an embodiment of the three-dimensional position measuring device according to the present invention, and FIGS. 2(a) and 2(b) show the output signal 40a and the received signal 11a before and after the measuring rod is moved. FIG. 1 is the measuring table, 2 is the object to be measured, 3 is the measuring rod, 4.5
8 is an ultrasonic oscillator, 8 is a microcomputer, 10 is an arithmetic unit, 11 to 16 are ultrasonic receivers, lla to 16a are received signals, 31 to 36 are phase difference measuring circuits, 31a to 36
a is a phase difference signal, 40. ．． 50 is an ultrasonic oscillation circuit, 40
a and 50a are output signals. Figure 2 (b)

Claims (5)

[Claims] (1) A measuring rod for specifying each part of the object to be measured placed on the measuring table, an ultrasonic oscillator integrated with the measuring rod, and a plurality of ultrasonic oscillators placed above the measuring table. A three-dimensional position measuring device comprising an ultrasonic receiver and an arithmetic device that calculates the three-dimensional position of each part of the object based on a reception signal that the ultrasonic receiver receives from the ultrasonic oscillator. (2) The arithmetic device includes an ultrasonic oscillation circuit corresponding to the ultrasonic oscillator and a phase difference measurement circuit, and the phase difference measurement circuit is configured to detect the output signal of the ultrasonic oscillation circuit and the received signal of the ultrasonic receiver. 2. The three-dimensional position measuring device according to claim 1, wherein the three-dimensional position measuring device inputs a phase difference signal, outputs a phase difference signal, and calculates the three-dimensional position of each part of the measured point based on the phase difference signal. (3) The three-dimensional position measuring device according to claim 1 or 2, characterized in that ultrasonic oscillators are provided at two locations on the measuring rod. (4) The three-dimensional position measuring device according to claim 3, wherein three ultrasonic receivers are provided for each ultrasonic oscillator. (5) The three-dimensional position measuring device according to claim 3 or 4, wherein the oscillation frequencies of the respective ultrasonic oscillators are different from each other.