JPS63111402A - Position measuring instrument - Google Patents

Abstract

PURPOSE:To identify a target body to be measured by detecting information for identifying the body to be measured from a light beam which is incident from the body to be measured. CONSTITUTION:A semiconductor optical position detection element (PSD) 1 supplies a light beam emitted by a spot light source on the body to be measured to a current-voltage converting circuit 2, which converts it into voltage signals x1 and x2, and y1 and y2. An adding circuit 31 and a subtracter circuit 41 calculate x1+x2 and x1-x2 and an adder circuit 32 and a subtracter circuit 42 output y1+y2 and y1-y2, whose amplitudes are extracted by an AC processing circuit 5. The dividing circuits 61 and 62 perform subtraction between them and outputs a subtraction signal. A multiplexer 8, a sample/hold circuit 9, and an A/D converter 10 are controlled by a processor 11. The processor 11 outputs position coordinates (x) and (y) inputted from the A/D converter 10 to an output circuit 2 together with discrimination data on the body to be measured when the discrimination data inputted from a frequency detecting circuit 7 matches with one of set modulation frequencies.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a position measuring device.

(Prior Art) FIG. 4 is a block diagram showing a conventional example of this type of optical position measuring device.

Light is irradiated from a point light source 41 of the object to be measured through a light source system 42 onto the detection surface of a PSD (semiconductor device sensing element "f-") 43, and when a light spot is imaged, a current signal xi, y+++ Vr2 are output, and current signals Xth to yt2 are sent to the current-voltage conversion circuit 44+
, 442, 443, and 444, the signals are converted into proportional voltage signals xi, X21 y++ y2, respectively. Voltage signal xl+ x7. yt+y2 is further input to the signal processing unit 45, where calculations for position measurement are performed.

In this case, the positional coordinates x and y of the light spot on the detection surface of the PSD 43 are obtained by the following equation.

However, -1≦X≦1. −1≦y≦1 By multiplying these coordinates x and y by the magnification of the optical system 42, the coordinates of the point light source 41 where the object to be measured is located can be obtained (Patent Application No. 60-267279 r optical system (See “Position Detector”).

(Problems to be Solved by the Invention) The conventional position measuring device described above determines the position of the light source from the position coordinates of the light spot imaged on the detection surface of the POS, and the target object to be measured is In most cases, the number of objects to be measured is limited to one, and when there are a plurality of objects to be measured as shown in FIG. 2, there is a drawback that they cannot be measured and identified at the same time.

(Means for Solving the Problems) The position measuring device of the present invention includes a light modulating means for imparting information for identifying each of the light rays emitted from the light sources of a plurality of objects to be measured, and a position measuring device to be measured. It has a measured object identifying means that identifies the measured object by detecting the information from the light beam incident from the object.

[For production]

Therefore, the position measuring device of the present invention uses a light modulation means to add information for identifying each of the light beams emitted by a plurality of scattered objects to be measured, and the position measuring device can identify the objects to be measured that it has. By detecting the information from the incident light beam from the object to be measured using the means, the object to be measured can be identified.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the main part configuration of an embodiment of the position measuring device of the present invention, and FIG. 2 shows a plurality of measured objects A, B, C.
, D are scattered, this embodiment uses the measured object A
FIG. 3 is a flowchart showing the identification operation of this embodiment.

Four measurement objects A, B, C, and D are scattered, and the light rays emitted from their point light sources are preset to different frequencies f^, f, f, respectively by a light modulation device (not shown).
, fc, and fD. pso t shall measure any one of the objects to be measured A, B, C, D,
The light rays emitted from the point light source are imaged as a light spot on the detection surface through an optical system (not shown). The current-voltage conversion circuit 2 converts current signals X+xi2+yil+yi2 corresponding to the coordinates of the light spot output from pso t into voltage signals X+, X2, yl, respectively.
Convert to y2. The addition circuit 3I calculates the sum of the voltage signal Xi and the voltage signal x2, and the subtraction circuit 42 calculates the difference between them.
The addition circuit 32 calculates the sum of the voltage signal y and the voltage signal y2, and the subtraction circuit 42 calculates the difference between them. The AC processing circuit 5 generates these AC sum signals Xl +x2, 'jI+y2, and the difference signal XI
Process X21 yI Y2 to extract and output their amplitudes. Division circuit 6. ．． 6. performs division using these outputs and outputs it as a division signal. Multiplexer 8, sample and hold circuit 9. Both to/D converters lO are controlled by processor +1 and transmit these coordinates x, y to processor 11. The frequency detection circuit 7 branches the sum signal Xl +X from the addition circuit 31, detects the modulation frequency of this signal, and outputs the corresponding identification data to the processor port. The processor 11 presets the modulation frequency fa,
fB, f(.

When the identification data corresponding to fo is set and the identification data input from the frequency detection circuit 7 matches one of the set modulation frequencies f^, fB, fc, f, the A/D converter 10 Position coordinates x, y input from
Output circuit 1 along with the identification data of the object to be measured that match the
Output to 2. The output circuit 12 transmits the position coordinates and identification data of the object to be measured to necessary locations.

Next, among the operations of this embodiment, the operation of identifying the object to be measured will be explained with reference to FIG. The position coordinate measurement operation is completely similar to the conventional example described above, and therefore will be omitted.

A sum signal XI +X2 is output from the adder circuit 3I (step S1), and the frequency detection circuit 7 detects the modulation frequency of the input sum signal and transmits it to the processor 11 as identification data (step S2). The processor 11 sequentially compares the input identification data with the data of each modulation frequency f^, fB, fc/fn set in advance (step S3゜S4*SS, 56), and when they match, the Output identification signals A, B, C, and D (step S7
).

Similar operations are repeated until the program ends, and the process ends when the program ends (step Sa).

〔Effect of the invention〕

As explained above, the present invention provides light modulation means for imparting information for identifying each of the light rays emitted from the light sources of a plurality of objects to be measured, and a light beam incident from the target object to be measured. The object to be measured identification means identifies the object to be measured by detecting the information from the object to be measured. It has the effect of being able to identify the measured object by comparing it with pre-set information for identifying each measured object, and it is useful for autonomous self-propelled cars and robots that operate over a wide range. It can be used as an external sensor.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the main part configuration of one embodiment of the position measuring device of the present invention, and Fig. 2 shows the measurement of the measured object A by this embodiment when a plurality of measured objects are scattered. FIG. 3 is a flowchart showing the identification operation of this embodiment, and FIG. 4 is a block diagram showing the configuration of a conventional example. 1-PSD, 2... current-voltage conversion circuit, 3
,．． 32--Addition circuit, 4, . 42-... Subtraction circuit, 5... AC processing circuit, 61+ 62... Division circuit, 7... Frequency detection circuit, 8... Multiplexer, 9... Sample-and-hold circuit, lO・-A /D
Converter, 11-... Processor, 12... Output circuit, X yll X i2+ yil+ y12"' current signal, Xll X2. yll y2... Voltage signal, x
, y...coordinates, A, B, C, D... object to be measured, 21-... position measuring device, S~S8... each step.

Claims (1)

[Claims] In a position measuring device that detects the position of a light source from a measurement value obtained by focusing a light beam incident from a light source on a light receiving surface of a semiconductor device detection element and measuring the output signal. , in the light rays emitted from the light sources of multiple objects to be measured,
It is characterized by having a light modulation means for providing information for identifying each object, and a measured object identification means for identifying the measured object by detecting the information from the light beam incident from the measured object. position measuring device.