WO2002090883A1

WO2002090883A1 - Position detector

Info

Publication number: WO2002090883A1
Application number: PCT/JP2002/004307
Authority: WO
Inventors: Tatsuyuki Ochi; Yasuaki Amemiya
Original assignee: Tokimec Construction Systems Inc.
Priority date: 2001-05-07
Filing date: 2002-04-30
Publication date: 2002-11-14
Also published as: JP2002328006A

Abstract

A position detector for detecting the position of a light beam by receiving the beam capable of relieving a restriction on the pitch of a light receiving element by a beam diameter, comprising a large number of light receiving elements (14) disposed in a row and a calculator (3d) for calculating a light receiving center position in the direction of the row based on the amount of received light, wherein a diffusion member (12) for diffusing the light (2) moving toward light receiving surfaces in the direction of the row is installed in front of the light receiving faces of the large number of light receiving elements (14), whereby, the light is radiated in a range wider than the light beam diameter obtained before the diffusion, the light beam can be received accurately whether element pitches are small or large, the light beam can be passed through the plurality of light receiving elements when the light beam is diffused, the diffusion in the direction orthogonal to the direction of the row can be reduced, and the light receiving elements can be disposed in multiple rows to surround a bar support member, and a flexible platy body or a film body can be used for the diffusion member.

Description

Description Position detection device Technical field

The present invention relates to a position detection device that receives a light beam and detects the position, and more particularly, has a large number of light receiving elements arranged in a row, and calculates a light receiving center position in the column direction based on the amount of received light. The present invention relates to a position detection device calculated by the device.

Such a position detecting device is usually used together with a projector that emits a laser beam while rotating or rotating at a angle of 360 ° or more or less, and when setting the light receiving unit, it is necessary to set the light receiving element in the column direction. Is made as orthogonal as possible to the scanning plane of the light beam, and position detection is performed based on the scanning plane.

It is useful for detecting vertical and horizontal positions in civil engineering and construction sites, and is used, for example, for measuring the unevenness of concrete on buildings and roads, and for controlling the leveling of bulldozers. In the leveling control device, the light receiving section is installed on the blade of the bulldozer, and the blade is automatically moved up and down so that the laser beam scanning surface, which is the finishing reference, is always at a predetermined position such as the center of the light receiving element row. Thus, accurate leveling work is performed. In addition, it is used for height measuring devices such as motor graders, asphalt finishers, and concrete leveling machines. It is also used for backhoe (excavator) excavation depth control equipment. Background art

A conventional position detecting device including a large number of light receiving elements arranged in a row and an arithmetic unit that calculates a light receiving center position in the column direction of the light receiving elements based on the light receiving amounts thereof receives a beam light. When detecting the position, calculation is performed such that the mounting position of each light receiving element is weighted by the amount of received light and calculated. In addition, only the light beam whose light reception amount has reached a predetermined threshold or more is regarded as valid signal data, and the light reception center position is calculated based on the light reception amount of one or more light receiving elements corresponding to the condition. There is something. Furthermore, an optical fiber is provided in front of the light receiving surface of the light receiving element (see JP-A-3-1-22). There is also a type in which a refraction member and a diffusion member are provided in front of the light receiving surface of the light receiving element (Japanese Patent Laid-Open No. 62-74607), but the refraction direction and the diffusion direction. Is designed to spread light traveling toward the light receiving surface in a direction orthogonal to the rows of light receiving elements, but not in the direction of the rows of light receiving elements. Disclosure of the invention

In such a conventional position detecting device, the position detecting ability is improved by using various methods, and in particular, when an optical fiber is provided in front of the light receiving surface, the pitch is wider than the pitch of the light receiving element. The light receiving position can be detected. Also, in the case of performing the weighting calculation, the light receiving position can be detected with a resolution finer than the pitch of the light receiving elements.

However, in any case, accurate measurement cannot be performed with a smaller number of light receiving elements than the number obtained by dividing the length of the measurement range by the diameter of the beam light. Therefore, if the measuring distance is long, the number of light receiving elements and additional members is reduced. There is an inconvenience that cost increases are inevitable. Therefore, in order to accurately perform position measurement over a longer measurement range while avoiding cost increase or reducing cost, specifically, the number of light receiving elements is smaller than the ratio of the measurement distance to the beam diameter. It is a technical issue to devise the structure of the position detection device so that accurate position measurement can be performed even with the light-receiving element. The present invention has been made to solve such a problem, and an object of the present invention is to realize a position detecting device in which a restriction imposed on a pitch of a light receiving element by a beam diameter is loose.

Hereinafter, first to sixth solving methods invented to solve such a problem will be described. A position detection device according to a first solution is a position detection device including: a large number of light receiving elements arranged in a row; and an arithmetic unit that calculates a light receiving center position of the light receiving elements in a column direction based on the received light amounts. In the above, a diffusion member is provided in front of the light receiving surfaces of the plurality of light receiving elements to transmit or reflect light traveling toward the light receiving surfaces and spread the light in the column direction. It is optional whether or not it can be expanded in the direction orthogonal to the column direction.However, in the orthogonal direction, from the viewpoint of preventing a decrease in the amount of received light, the width should not exceed or exceed the width of the light receiving element. It is desirable to narrow down to fit.

In the position detecting device according to the first solution, since the light directed to the light receiving element is spread by the diffusion member while the light is traveling, at least the light in the column direction of the light receiving element is not diffused. Since the light is applied to a range wider than the beam diameter, the pitch of the light receiving elements can be correspondingly widened, and even in such a case, light is received by any of the light receiving elements. The change in the light receiving state due to the diffusion of light may be corrected by an operation based on the diffusion rate or the like.

Thus, even when the arrangement pitch of the light receiving elements is narrower or wider than the diameter of the irradiation light, the light is accurately received, and the light receiving position is obtained.

Therefore, according to the present invention, it is possible to realize a position detecting device in which the restriction imposed on the pitch of the light receiving elements by the beam diameter is loose.

As a result, if the pitch of the light receiving elements is increased, a relatively small number of light receiving elements can detect the position in a wide range. Also, if the pitch of the light receiving elements is the same, more light receiving elements receive light at the same time, and the amount of data indicating the distribution of the received light amount increases, so that the degree of freedom of calculation, accuracy, and resolution are improved. It becomes possible. A position detection device according to a second solution is the position detection device according to the first solution, wherein the diffusing member spreads a plurality of light receiving elements when spreading the light beam. It is like that.

In the position detecting device according to the second solution, when the light beam is irradiated, a plurality of received light amount data is obtained.

As a result, in calculating the light receiving center position, it is possible to use various calculations such as a weighting calculation, a calculation to which an approximate function is applied, an interpolation calculation, an extrapolation calculation, a maximum likelihood calculation, and a fuzzy calculation. .

Therefore, according to the present invention, it is possible to realize a position detecting device in which not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter but also the restrictions on the calculation method are loose. As a result, accurate position measurement can be performed. A position detection device according to a third solution is the position detection device according to the first or second solution, wherein the diffusion member is provided in a direction orthogonal to the column direction in comparison with the diffusion in the column direction. Something that reduces diffusion is adopted.

In the position detecting device according to the third solution, since the diffusion of the light receiving element in the direction orthogonal to the column direction is small, the irradiated light is laterally separated from the light receiving element by the diffusion. The rate of losing is small. .

As a result, even if a diffusion member is introduced before the light receiving element, a decrease in the amount of received light is suppressed and prevented, so that the sensitivity of the light receiving element does not need to be increased.

Therefore, according to the present invention, it is possible to realize a position detecting device in which not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter but also the restrictions on the selection of the light receiving elements are loose. A position detection device according to a fourth solution is the position detection device according to the first to third solutions, wherein a plurality of rows of the light receiving elements are formed around a support member. is there. The support member is preferably a long member such as a bar or a plate, but is not limited thereto, and may be any member in which a plurality of rows of light receiving elements can be arranged on the outer peripheral surface, the outer surface, the front and back surfaces, and the like.

In the position detecting device according to the fourth solution, since the support member is surrounded by the light receiving elements arranged in a double row, when the light is irradiated toward the support member, the irradiation is Even if the light is emitted from the direction, any light required for position detection is performed by any of the light receiving elements as long as the light hits the outer peripheral surface or the like of the support member. As a result, it is possible to receive light over a wide angle range of approximately 360 °, so that it is not necessary to perform one adjustment such as matching the direction with the projector. Therefore, according to the present invention, it is possible to realize a position detecting device in which not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter but also the restrictions on the light receiving direction are loose. The position detecting device of the fifth solution is the position detecting device of the first to fourth solutions. Wherein the diffusion member is made of a flexible plate or film.

In the position detecting device according to the fifth solution, the diffusion member and its support are separately formed and processed, and then the diffusion member is attached to the support. Deforms according to the shape of the support.

This makes it possible to easily equip the diffusion member not only with a flat surface but also with a curved surface.

Therefore, according to the present invention, it is possible to realize a position detecting device in which not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter are loose, but also the restrictions on the installation of the necessary diffusion member are loose. A position detection device according to a sixth solution is the position detection device according to any one of the first to fifth solutions, wherein the computing device corresponds to the row of the light receiving elements when calculating the light receiving center position. A maximum value is obtained for the data sequence of the received light amount obtained, and when a plurality of maximum values are obtained, a process of suppressing the data value is performed for each occurrence of the maximum value other than the maximum value. It is.

In such a position detection device of the sixth solution, if there is reflected light in addition to direct light reception, and if those light reception positions are shifted, a plurality of local maximum values may appear and there is no change. The calculated value of the center position shifts closer to the position of the reflected light than the position of the direct light due to the data of the reflected light, but the data value suppression processing is performed for the location where the maximum value corresponding to the reflected light appears Therefore, an undesired change in the calculated value due to the reflected light is avoided or suppressed.

Thus, even if there is reflected light, the position can be accurately detected.

Therefore, according to the present invention, it is possible to realize a position detecting device in which not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter but also the restrictions on the use environment are loose. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 relates to a first embodiment of the position detecting device of the present invention, wherein (a) FIG. 2 is a side view of a position detection system in which a projector for rotatingly irradiating a beam and a position detection device of the present invention are combined, and (b) is a perspective view of a light receiving unit in the position detection device of the present invention. FIG. 2 is a block diagram of the arithmetic unit. FIG. 3 shows the operation of the diffusion member in comparison, where (a) relates to a state without the diffusion member and (b) relates to a state where the diffusion member is provided. FIG. 4 shows the effect of the diffusion member on the light receiving element mounting pitch in comparison, wherein (a) relates to a state without the diffusion member and (b) relates to a state where the diffusion member is provided. The two-dot chain line shows the continuous intensity distribution of the laser beam, and the solid line shows the distribution state sampled by the light receiving element. Fig. 5 shows an example of calculation based on the light receiving condition. (A) and (b) show the light receiving condition and (b) the calculating condition with respect to the good light receiving condition. (C) and (d) relate to the light receiving state where small reflections overlap, (c) is the light receiving state, and (d) is the calculation state. The dashed line indicates the threshold value, and the dashed line indicates the portion of the received light amount data that has been reduced by the noise suppression processing. The received light amount data is forcibly set to zero.

FIG. 6 shows an example of calculation based on a light receiving state in which large reflection is superimposed on the second embodiment of the position detecting device of the present invention, where (a) is a light receiving state, (b) is an input state, and (c) Is the maximum value detection state, and (d) is the calculation result. The dashed line indicates the threshold value, and the broken line indicates the portion of the received light amount data that has been reduced by the noise suppression processing or the reflection component suppression processing.

FIG. 7 shows the structure of a main part of a third embodiment of the position detecting device of the present invention, (a) is a plan view of a light receiving section, (b) is a front view of a light receiving element and a support member, (c) ) Is the right side view.

FIG. 8 shows an example of application of a fourth embodiment of the position detecting device of the present invention to a floor unevenness measuring machine, where (a) is a side view and (b) is a plan view.

FIG. 9 shows an application example of a bulldozer to a blade control device according to a fifth embodiment of the position detecting device of the present invention, (a) is a perspective view of a main part, (b) is a height control state, (c) relates to the tilt control state. Fig. 10 shows the running conditions, (a) is a plan view and (b) is a side view.

FIG. 11 is a perspective view of a main part showing an example of application of a sixth embodiment of the position detecting device of the present invention to a heavy equipment attitude control device. FIGS. 12 and 13 show the overall structure of a position detecting device according to a seventh embodiment of the present invention. FIG. 12 (a) is a perspective view, FIG. 12 (b) is a vertical sectional front view, and FIG. 12 (c) is a cross-sectional plan view.

FIG. 13 shows the relationship between the installation position of the diffusion member and the mounting pitch of the light receiving elements in the eighth embodiment of the position detecting device of the present invention, and FIG. (B) is where the light beam travels between the light receiving elements.

Description of reference numerals attached to drawings

1 Floodlight (Laser beam rotating irradiation device, light emitter)

Two-beam light (scanning laser light, rotating laser light, turning beam light)

3 Position detection device (height measurement device, moving object, traveling vehicle, heavy equipment)

3a leg (foot, wheel, crawler)

3 b Detector body (support for light-receiving part)

3 c Light-receiving part (light-receiving element array part)

3d arithmetic unit (electronic circuit)

3 e handle

3 f Operation section

3 g receiving window

3 h display

4 Measurement surface (floor surface, road surface)

Five

6 blades (movable member of bulldozer, height controlled object)

7 Movable members (objects to control the attitude of heavy machinery)

1 1 outer cylinder (transparent protective cover, diffusion member support)

1 2 Diffusion member (anisotropic diffusion film)

1 3 Bar-shaped support member (plate-shaped support member, light-receiving element support member)

1 4 Light receiving element (photoelectric conversion member)

2 1 Amplifier circuit (amplifier)

2 2 Peak hold circuit (auto reset)

2 3 A / D conversion circuit 2 4 Microprocessor

2 4a Input routine (data sampling means)

2 4 b Received light amount data string (Laser beam intensity distribution data)

2 4 c Center position calculation routine

2 4d output routine

2 4 e Maximum value

2 4 f Threshold setting routine (threshold setting means)

2 5 D / A conversion circuit (threshold setting means)

2 6 A / D control circuit (A / D conversion start control) Best mode for carrying out the invention

Specific embodiments for implementing the position detecting device of the present invention will be described with reference to the following first to eighth embodiments.

The first embodiment shown in FIGS. 1 to 5 embodies the first to fifth solutions described above, and the second embodiment shown in FIG. The third embodiment shown in FIG. 7 is a modification of the third embodiment. Also, the fourth embodiment shown in FIG. 8, the fifth embodiment shown in FIGS. 9 and 10, the sixth embodiment shown in FIG. 11, and the sixth embodiment shown in FIG. The seven embodiments are all application examples. Further, the eighth embodiment shown in FIG. 13 is a more specific version of the second solution described above.

In the drawings, for simplicity and the like, base plates, fasteners such as frames and ports, and coupling tools such as hinges are omitted from the drawings, and are necessary and related to the description of the invention. Those are shown mainly. First embodiment

A specific configuration of the first embodiment of the position detection device of the present invention will be described with reference to the drawings. Fig. 1 shows the basic structure, (a) is a side view of a position detecting system in which a projector for rotatingly irradiating a laser beam is combined with the position detecting device of the present invention, and (b) is a side view of the present invention. FIG. 3 is a perspective view of a light receiving unit in the position detecting device of the present invention. FIG. 2 is a block diagram of the arithmetic unit.

The position detecting device 3 (see Fig. 1 (a)) has a vertically long light receiving portion 3c protruding vertically upward to receive the laser beam light 2 radiated horizontally from the projector 1, and a leg portion on the measuring surface 4. A detection device main body 3b that lowers 3a to support the light receiving unit 3c from below, and a calculation device 3d that is stored in the detection device main body 3b and operates with a storage battery or the like (not shown). The leg portion 3a is provided as appropriate according to the application, and is a fixed leg, a telescopic leg, a rolling wheel, a driving wheel, a steering wheel, a crawler, or the like. Sometimes, they are omitted. The detection device main body 3b is also provided in a variety of forms depending on the ablation, such as a dedicated box-shaped body, a vehicle body, a movable member mounted on a work vehicle or heavy equipment, or an automatic machine. It may be divided into a movable member that supports the light receiving unit 3c and a housing that houses the arithmetic unit 3d.

The light receiving section 3c (see FIG. 1 (b)) is often formed as a straight rod having a diameter of several centimeters and a length of several tens of centimeters. It may be thicker, thinner, longer or shorter as long as it can be held in a line in the longitudinal direction. In this example, the light receiving elements 14 are arranged at equal pitches on the four side surfaces of the rod-shaped support member 13 having a prismatic shape, with the light-receiving surface facing outward (in the figure, each side surface of the rod-shaped support member 13). Only three light-receiving elements 14 are drawn). The rod-shaped support member 13 is accommodated in the axial center position of the cylindrical outer cylinder 11 in an idle state (the illustration of the fixed state of the end and the like is omitted). The diffusion member 12 is attached to the entire peripheral surface, and the outer cylinder 11 also serving as a cover is made of a transparent material such as acrylic. It comprises a large number of light receiving elements 14 arranged in four rows surrounding 3 and a diffusion member provided at a certain distance in front of the light receiving surfaces.

The diffusion member 12 may be a member known in Japanese Patent Application Laid-Open No. 62-74607 or the like, or may be any other member. For example, acryl, By subjecting a transparent plastic film such as polycarbonate to appropriate surface treatment or fine unevenness processing, a plate-like or film-like body having a light diffusion function and flexibility is obtained. At that time, the diffusing function also has anisotropy, and the transmitted light is expanded in a certain direction. It should be scattered but not as diffused as possible in the direction perpendicular to it. Then, when attaching the diffusion member 12 to the outer cylinder 11, the diffusion direction is adjusted to the direction of the axis of the outer cylinder 11. Thus, while the diffusion member 12 spreads the light traveling toward the light receiving surface of the light receiving element 14 in the column direction of the light receiving element 14, the diffusion in the direction orthogonal to the diffusion is smaller than the diffusion. Become. When selecting the distance between the diffusion member 12 and the light receiving element 14 or the pitch of the light receiving element 14, the diameter of the light beam 2 and the diffusion capacity of the diffusion member 12 are taken into consideration, and the diffusion member 1 is selected. Selection is made so that when the light beam 2 passing through 2 reaches the side surface of the rod-shaped support member 13, it spreads at least twice the array pitch of the light receiving elements 14. Thus, the diffusing member 12 spreads the light beam 2 over a plurality of light receiving elements 14 when spreading the light beam 2.

The light receiving element 14 photoelectrically converts the amount of light received by the light beam 2 received on the light receiving surface and outputs the converted light. As for, parallel connection corresponding to the double row is introduced. That is, the outputs of the respective light receiving elements 14 are OR-coupled to each other in the same order in each column, corresponding to the four columns. Thus, even if the light beam 2 strikes any side surface of the rod-shaped support member 13, the amount of light received at that position is appropriately reflected. Moreover, for the arithmetic unit 3d, it is sufficient to process only one row, that is, no matter how many rows of the light receiving elements 14 are arranged, the received light amount data to be input and calculated is It is after being put together.

The arithmetic unit 3d (see FIG. 2) calculates the light receiving center position in the row direction of the light receiving elements, that is, in the longitudinal direction of the light receiving section 3c, based on the light receiving amounts of the large number of light receiving elements 1.4. In addition, a microphone port processor 24 is provided to process the operation with a programmatic electronic circuit, and an input circuit 21 to 2 for converting the output of the light receiving element 14 into digital data and taking it into the microprocessor 24. 3 are also provided. Further, a start control circuit 25 + 26 for performing timing control such as input start for the input circuits 21 to 23 is also provided.

The input circuits 21 to 23 include an amplifier circuit 21 for amplifying the combined output of the four light receiving elements 14 and a reset automatically and repeatedly at a predetermined cycle corresponding to the scanning cycle of the light beam 2. To return to the reset state due to slow discharge, etc. A set of a peak hold circuit 22 that holds the maximum value of the output of the path 21 and an AZD conversion circuit 23 that converts the analog output into a digital value is provided for one row of the light receiving element 14.

The start control circuit 25 + 26 includes a D / A conversion circuit 25 for converting the threshold value transmitted from the microprocessor 24 as a digital value into an analog value, the threshold value and the output of each amplification circuit 21. And an AZD control circuit 26 that controls to start A / D conversion operation for all A / D conversion circuits 23 at the same time if even one output exceeds the threshold value. ing.

The microprocessor 24 receives the received light amount data from each of the AZD conversion circuits 23 and updates the received light amount data string 24 b in the memory. A center position calculation routine 24c for calculating a light receiving center position by performing a weighting calculation based on 4b, for example, and an output routine 24 for outputting the calculation result to a recording medium or a host processor (not shown) according to the application purpose. Based on d and the maximum value 24 e in the received light amount data string 24 b obtained during input by the input routine 24 a, for example, multiply it by a predetermined value less than “1” to obtain a threshold. Is sent to the DZA conversion circuit 25. The threshold setting routine 24f is installed. Then, those program processes are repeatedly executed at the above-described predetermined cycle.

A typical example of the method of calculating the light receiving center position by the center position calculation routine 24c is as follows. A distribution function such as a Gaussian distribution having one peak is applied to the intensity distribution of the laser beam, and the peak of the distribution function is obtained. It calculates the position. Specifically, assuming that the distance from the origin of the mounting position of each light receiving element 14 in the row of light receiving elements 14 to the origin is L n, and the light receiving amount of each light receiving element 14 is P n, the light beam 2 The light receiving center position Lx can be obtained by calculating the equation [Lx = ∑ (LnXPη) / ΣΣη]. Thus, the position detecting device 3 detects the light receiving center position with a resolution and accuracy finer than the mounting pitch of the light receiving elements 14.

The usage and operation of the position detecting device of the first embodiment will be described with reference to the drawings. FIG. 1 (a) is a side view of detecting the height of the laser beam scanning surface in combination with a projector for rotatingly irradiating a laser beam. (A) relates to a state without a diffusion member, and (b) relates to a state with a diffusion member. FIG. 4 shows the effect of the diffusion member on the light-receiving element mounting pitch in comparison, wherein (a) relates to a state without the diffusion member and (b) relates to a state in which the diffusion member is provided. Further, FIG. 5 shows an example of calculation based on the light receiving state. (A) and (b) show the light receiving state, (b) shows the calculating state, and (c) and (b) show the good light receiving state. In (d), the light receiving state where small reflections are superimposed is shown in (c), and the calculated state is shown in (d). In each graph, the two-dot chain line indicates the continuous intensity distribution of the laser beam, the solid line indicates the distribution state sampled by the light receiving element, the one-dot chain line indicates the threshold value, and the dashed line indicates the amount of received light. The part of the data that was reduced by the noise suppression processing of the input routine 24a is shown.

When measuring the height of the measuring surface 4 using the position detecting device 3 and the projector 1 (see Fig. 1 (a)), select one of the points on the measuring surface 4 as a reference point and project it there. Set optical device 1. At this time, the tripod of the projector 1 is adjusted so that the beam light 2 that rotates 360 ° scans one horizontal plane. In addition, the position detecting device 3 is placed on the measurement surface 4 where the height is to be measured. At this time, the light receiving section 3c pierces the scanning surface of the light beam 2 and keeps a vertical / vertical state as much as possible. Since many light receiving elements 14 face the light receiving surface in all directions, it is not necessary to worry about the direction of the side surface of the position detecting device 3.

Then, the light beam 2 that travels horizontally with a diameter of several mm to a few mm and reaches the light receiving portion 3c directly hits the row of the light receiving elements 14 without the diffusion member 12 (FIG. 3 (a)). (See Fig. 4 (a).) In contrast to this, the light-receiving element 14 mounted in that area is sensitive (see Fig. 4 (a)). In this case, however, the diffusion member 12 is provided (see Fig. 3 (b)). The beam diameter expands in the row direction of the light-receiving elements 14, and the light-receiving elements 14 mounted in the wide area are responsive (see Fig. 4 (b)). By broadening the mounting pitch of the light receiving element 14 at a ratio that the light beam 2 spreads at the light receiving element 14, almost the same received light amount data can be obtained although the light amount is small. Since the isotropic type is adopted, the decrease in the amount of received light is Of being the spread was an amount corresponding to the suppression gap, the use of the wider of the light receiving surface at low cost to the light receiving element 1 4, it can be avoided. Each time the light beam 2 scans in the negative direction, the data of the received light amount (see FIG. 5 (a)) in which the outputs of the light receiving elements 14 in a plurality of rows are put into one row are input to the input circuits 21 to 23. The received light amount data sequence 24b is taken in by the input routine 24a via the input routine 24a. At this time, the threshold value is recalculated by the threshold value setting routine 24 f based on the maximum value 24 e and is sent to the A / D control circuit 26 via the D / A conversion circuit 25. Is updated to the latest one according to the immediately preceding sampling result. (See FIG. 5 (b).) In addition, the input routine 24a performs noise suppression processing on each data of the received light amount data string 24b, and cuts off the data by the threshold value. That is, the threshold value is subtracted from the data values above the threshold value, and data values below the threshold value are set to "◦". Therefore, even if undesired reflected light that deviates from the scanning surface of the light beam 2 and strikes another object before exiting the projector 1 and reaching the position detecting device 3 (see FIG. 5 (c)) If the amount of received light does not exceed the threshold, the undesired data is discarded, so that almost the same data as in the proper state without reflected light is obtained in the received light amount data string 24b (Fig. 5 ( d))). Based on this, the above-described predetermined calculation is performed by the center position calculation routine 24c to calculate the light receiving center position of the beam light 2 (see FIGS. 5 (b) and (d)). Processed by output routine 24d.

In this manner, the position of the light beam 2 is detected by the position detection device 3 every time the beam light 2 is scanned. In addition, since the detection of the light receiving center position is released or relaxed by the calculation of the arithmetic unit 3d from the restraint due to the mounting pitch of the light receiving elements 14, the mounting pitch of the light receiving elements 14 is expanded, so that a wide range of position detection is inexpensive. Can be done at any time. However, it is not essential that the ratio at which the light beam 2 spreads at the light receiving element 14 based on the interposition of the diffusion member 1 and the enlargement rate of the mounting pitch of the light receiving element 14 be equal. It is also possible to improve the resolution and accuracy of position detection with little or no increase in the mounting pitch of 14 with little or no increase. Second embodiment A specific configuration of a second embodiment of the position detection device of the present invention will be described with reference to the drawings. Fig. 6 shows an example of calculation based on the light receiving state in which large reflection is superimposed. (A) is the light receiving state, (b) is the input state, (c) is the maximum value detection state, and (d) is the calculation result. is there. In the figure, a dashed line indicates a threshold value, and a broken line indicates a portion of the received light amount data which has been reduced by the noise suppression processing or the reflection component suppression processing.

This position detection device differs from that of the first embodiment in that the center position calculation routine 24c is modified so as to also perform a reflection component suppression process using an extreme value.

In other words, the new center position calculation routine 24c performs a process of finding as many local values as possible for the received light amount data sequence 24b prior to the calculation of the center position by the above-described weighting calculation and the like. And a process of suppressing the single value. The data value suppression processing only needs to be performed when a plurality of local maxima are obtained. However, when a plurality of local maximal values other than the maximum value are found, they are applied to each occurrence location. The specific contents of the processing may be that the data value of the location where the local maximum occurs is suddenly set to “0”, or the data value of the location where the local maximum occurs is reduced to a predetermined ratio less than “1”. Assuming a Gaussian distribution or the like as the intensity distribution, it is also possible to suppress not only the location where the local maximum value appears but also the data value in the vicinity thereof. In any case, the process is repeated until no maximum value other than the maximum value can be found. The data value which falls below "◦" is forcibly set to "0".

In this case, for the sake of comparison with the above-mentioned case (see FIG. 5 (c)), it is assumed that the amount of reflected light received has increased from that time (see FIG. 6 (a)). If it exceeds the threshold, the data value does not become “◦” but stays in the received light amount data string 24b even if noise suppression processing is performed to reduce the threshold (see Fig. 6 (b)). When the local maximum value is searched for this received light amount data sequence 24b, a local maximum value 1 corresponding to direct light and a local maximum value 2 corresponding to reflected light are found (see Fig. 6 (c)). . Among them, the maximum value 1 which is also the maximum value is kept as it is, and the data value suppression processing is applied to the occurrence position of the maximum value 2 which is the maximum value other than the maximum value. Then, in the received light amount data string 24b, data values substantially similar to the data values when there is no large reflected light (see FIGS. 5 (b) and 5 (d)) remain (see FIG. 6 ( d) See).

Thus, in this case, even if there is large reflected light exceeding the threshold value, the effect can be eliminated. Third embodiment

A specific configuration of a third embodiment of the position detection device of the present invention will be described with reference to the drawings. FIG. 7 shows the structure of the main part, (a) is a plan view of the light receiving section, (b) is a front view of the light receiving element and the support member, and (c) is a right side view thereof.

This position detecting device is different from those of the first and second embodiments in that the supporting member 13 is changed from a square rod shape to a plate shape.

A double-sided printed wiring board is used for the support member 13, and a single row of light receiving elements 14 is mounted on one surface with the leads bent at about 90 °, and the light receiving elements 14 are mounted on the other surface. 14 are mounted in parallel with two rows with the lead bent by about 30 °, and the three rows of light-receiving elements 14 change the direction by 120 ° to share 360 °. I have. In this case, the number of light receiving elements 14 can be reduced and the sensitivity change according to the direction can be reduced as compared with the above-described four-row type. Fourth embodiment

The floor surface unevenness measuring instrument whose side view and plan view are shown in FIG. 8 employs the above-described position detecting device in its position detecting section.

The position detecting device 3 is movable by adopting a rolling wheel on the leg 3a, and is further provided with a moving distance meter for measuring the moving distance. An operating unit 3f is provided at the tip of a handle 3e extending upward from the detection device main body 3b, so that a moving pattern, necessary initial values, and the like can be set. In addition, the detection device body 3b includes a recording device that records a series of received light amount data, an information processing device that processes the data to create a contour line, and the like, in addition to the calculation device 3d, or separately. It is provided integrally with the device 3d.

When measuring the unevenness of the floor 4 of a newly built or repaired building 5 using such a floor unevenness measuring instrument, a floodlight can be installed over almost the entire measurement surface 4. 1 is set, and then the position detection device 3 is moved according to a preset movement pattern. When setting the movement pattern, enter the type, position, and movement direction of each element of the movement pattern, and move the position detection device 3 on the measurement surface 4 completely (see the arrow in Fig. 8 (b)). See broken line). Then, the position detecting device 3 measures the light receiving height of the light beam 2 while measuring the moving distance with the moving distance meter, obtains a plane position according to the moving pattern and the moving distance, and based on the detected light receiving height, the floor position is obtained. Calculate the unevenness of surface 4. Fifth embodiment

The leveling control device whose perspective view is shown in Fig. 9 (a) also uses the above-mentioned position detection device. Specifically, two light receiving sections 3c are implanted in the blade (movable member) of a bulldozer (heavy machine), and based on the position of the light beam 2 received by the light receiving sections 3c, the positions are aligned. (Refer to Fig. 9 (b).) Height control is performed so that the height of blade 6 follows the target value. If both positions are displaced (refer to Fig. 9 (c)), the displacement is eliminated. Such tilt control is also performed.

(See Fig. 10) Also, when leveling a wide area or a road surface with a large difference in elevation with this bulldozer, a plurality of projectors 1 are installed along the measurement surface 4 and each projector 1 scans and irradiates. A plurality of reference planes having different allocation ranges and / or different heights are created by the light beam 2 to be emitted. The bulldozer (position detecting device 3) has a long light receiving portion 3c extending over both reference surfaces. Then, when the bulldozer is running, if the light beam 2 is received from only one light emitter 1, ground leveling control and attitude control are performed based on the beam light 2, and a plurality of light emitters 1 When light beam 2 is received, ground control and attitude control are performed based on the strongest light beam 2. Alternatively, ground control and attitude control are performed based on the light beam 2 closest to the center position of the light receiving unit 3c. In this way, the reference floodlights 1 are sequentially switched, and the leveling work of the measurement surface 4 by the bulldozer is automatically controlled over a long distance. Sixth embodiment The heavy equipment attitude control device whose perspective view is shown in FIG. 11 also employs the above-described position detection device for its position detection unit.

In this case, three light receiving sections 3c are implanted in the movable member 7 of the heavy equipment. Then, when the light beam 2 is emitted from the light projector 1, the light receiving position is detected by each light receiving unit 3c. Since they are arranged corresponding to the positions of the vertices of the triangle, the posture of the movable member 7 and the heavy equipment is tertiarily calculated by performing a predetermined operation based on the positions, that is, an operation of solving an equation based on a known geometric relationship. It can be grasped from the beginning, and its posture (pitching, mouth ring, bowing) can be controlled. Seventh embodiment

The position detecting device whose overall structure is shown in FIG. 12 is a small-sized and inexpensive simple type by limiting the range in which the light beam 2 can be received. That is, in the position detecting device 3, the light receiving unit 3c is also combined with the detecting device body 3b in a box shape, and the arithmetic unit 3d is stored in the position detecting device 3 together with the diffusing member 12 and the light receiving element 14. . In addition, an elongate light receiving window 3 g is formed on the outer surface thereof, and a display portion 3 h for numerically indicating the light receiving position is provided on the outer surface. The diffusion member 12 is not a transmission type but a reflection type, and the light receiving elements 14 are mounted in a single row on one surface of the elongated plate-shaped support member 13. Thereby, the position detection device 3 becomes thin and highly portable.

In this case, the position detecting device 3 is held by hand or attached to the surface to be measured, and the light receiving window 3 g is directed toward the projector 1. Then, the light beam 2 radiated from the light receiving window 3 g is reflected by the surface of the diffusion member 12 and advances toward the light receiving element 14 while spreading only in the longitudinal direction, that is, in the column direction. Then, the light receiving center position in the row of the light receiving elements 14 is obtained based on the light receiving state, and is displayed on the display unit 3h. Thus, also in this case, the light receiving position can be easily known by reading the display value.

Although illustration is omitted, when battery operation is used to enhance portability, it is advisable to incorporate an appropriate battery pack or detachably attach an external battery pack. Eighth embodiment FIG. 13 shows the relationship between the installation position of the diffusion member 12 and the mounting pitch of the light receiving element 14 .The position detection device uses a diffusion member in order to perform a wide range of measurement with as few light receiving elements 14 as possible. The light beam 2 expanded in step 12 is made to reach two or more light receiving elements 14.

Specifically, the value obtained by multiplying the distance d between the diffusion member 1 2 and the row of the light receiving elements 14 by the tangent (tan の) of the diffusion angle 0 of the diffusion member 12 is doubled, and the light beam 2 The pitch a and the distance d are determined so that the value obtained by adding the diameter D0 of the light receiving element 14 is twice or slightly larger than the mounting pitch a of the light receiving element 14.

If expressed by the relational expression, [2 x a ≤ D o + 2 X d xtan0] is satisfied.

One typical numerical example is

Mounting pitch of light receiving element 14 a = 12.7 mm

Distance between diffusion member 1 2 and light receiving element 14 d = 25 mm

Laser beam diameter 2 Do = 3mm

Diffusion angle of diffusion member 1 2 0 = 40 °

It is.

In this case, if the approximate values of tan0 = l and Do = 0 are adopted, the above relational expression is simplified to [a≤d]. However, in consideration of the effective strength of the light receiving element 14 and the variation in components, it is a practical design condition to impose the relational expression [2 x a ≤ d]. That is, it is preferable that the distance d between the diffusion member 12 and the row of the light receiving elements 14 be approximately twice the mounting pitch a of the light receiving elements 14. As is clear from the above description, in the position detecting device of the present invention, the light is applied to a wider range than the beam diameter of the light before diffusion, so that the arrangement pitch of the light receiving elements is increased. Light was accurately received regardless of whether the light diameter was narrow or wide, and as a result, a position detection device in which the restrictions imposed on the pitch of the light receiving elements by the beam diameter were loose was realized.

Further, in the position detecting device of the present invention, a plurality of received light amount data can be obtained with respect to irradiation of the beam light, so that the pitch of the light receiving element is imposed by the beam diameter. A position detection device that is not only less restrictive but also less restrictive regarding the calculation method We were able to.

Further, in the position detecting device of the present invention, since the diffusing member has anisotropy, not only the restrictions imposed on the pitch of the light receiving elements due to the beam diameter but also the restrictions on the selection of the light receiving elements are relaxed. A position detection device was realized.

In addition, the position detection device of the present invention is capable of receiving light regardless of the direction from which light is received. A position detector with less restrictions on the direction of the position could be realized.

Further, in the position detecting device of the present invention, the diffusion member and its support are individually formed and deformed so that the diffusion member conforms to the shape of the support, so that the beam diameter can be reduced. As a result, it was possible to realize a position detection device in which not only the restrictions imposed on the pitch of the light receiving element but also the restrictions on the installation of the necessary diffusion member were loose.

Further, in the position detection device of the present invention, by suppressing the received light amount data of the reflected light and leaving the received light amount data of the direct light, the pitch of the light receiving element is imposed by the beam diameter. In addition to the strict restrictions imposed on the position detection device, the restrictions on the operating environment were also lenient.

Claims

The scope of the claims

1. A position detecting device comprising: a large number of light receiving elements arranged in a row; and a calculating device for calculating a light receiving center position in a column direction of the light receiving elements based on the amount of received light, the light receiving of the large number of light receiving elements A position detecting device, further comprising a diffusion member provided in front of the surface to spread light traveling toward the light receiving surface in the column direction.

2. The position detecting device according to claim 1, wherein the diffusing member spreads the beam light over a plurality of the plurality of light receiving elements.

3. The position detection device according to claim 1, wherein the diffusion member has less diffusion in a direction orthogonal to the diffusion direction than in the column direction.

4. The position detecting device according to claim 1, wherein a plurality of rows of the light receiving elements are formed so as to surround a support member.

5. The position detecting device according to claim 1, wherein the diffusion member is formed of a flexible plate or a film.

6. When calculating the light receiving center position, the arithmetic unit obtains a local maximum value for the data sequence of the light receiving amount corresponding to the row of the light receiving elements, and when a plurality of local maximum values are obtained, the local maximum value other than the maximum value is calculated. 2. The position detecting device according to claim 1, wherein a process for suppressing a data value is performed for each of the occurrence locations.

7. A position detecting device comprising: a large number of light receiving elements arranged in a row; and a calculating device for calculating a light receiving center position in a column direction of the light receiving elements based on the light receiving amounts thereof. A diffusing member for spreading the light beam traveling toward the column direction is provided in front of the light receiving surface, and a value obtained by multiplying a distance between the diffusing member and the row of light receiving elements by a tangent of a diffusion angle of the diffusing member is 2 A position detecting device, wherein a value obtained by adding the diameter of the light beam to twice the diameter is at least twice the mounting pitch of the light receiving elements.

8. A position detecting device comprising: a large number of light receiving elements arranged in a row; and a calculating device for calculating a light receiving center position of the light receiving elements in a column direction based on the light receiving amounts thereof, wherein a light receiving surface of the light receiving elements is A diffusing member for expanding the light beam traveling toward the column direction A position detecting device provided in front of the light receiving surface, wherein a distance between the diffusion member and the row of the light receiving elements is substantially twice a mounting pitch of the light receiving elements.