Laser receiver, level detection system, control method of laser receiver

Abstract

To further improve accuracy for detecting height even if a laser beam of a prescribed width is received in an environment where disturbance tend to affect and a construction circumstance where a machine tool moves.SOLUTION: A laser receiver arranges a laser beam to be plane scanned with a prescribed width so as to be symmetrical to a vertical direction based as reference on the center position on a substrate 500 on which a plurality of light receiving elements are disposed in a vertical direction according to a prescribed accuracy distribution.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a laser receiver, a level detection system, and a control method for a laser receiver for acquiring reference height information of a horizontal plane used by a moving machine tool at a construction site.

Background Art

[0002] At a construction site of a large-scale high-rise building, fresh concrete is poured onto a floor surface where steel bars have been processed to form a floor surface. At this time, when a machine tool for leveling the fresh concrete performs a leveling operation, a light receiving device that receives laser light with a predetermined width scanned from a rotating laser located at a specific position functions integrally with a rotating laser device. In the rotating laser irradiator, the laser is irradiated horizontally at about 300 to 1000 rpm. Note that 600 rpm is often adopted as the rotation speed.

[0003] The rotating laser system is used in combination with the above laser irradiator and laser receiver. Generally, an operator recognizes the laser position by reading the display of the receiver.

[0004] Hereinafter, an example of a height measurement process will be shown. (1) The operator turns the light receiving surface of the laser receiver in the laser direction. (2) The receiver measures the distance between the center of the light receiving surface and the position of the received laser. (3) The operator recognizes the difference (height difference) between the center of the light receiving surface and the laser position based on the numerical value displayed on the receiver or the sound or light generated by the receiver.

[0005] Note that when the rotating laser irradiator rotates at a speed of, for example, 600 rpm, the laser scans (crosses) the receiver at a cycle of 100 ms. The receiver captures the position of this light and measures the height.

[0006] Here, when light-receiving elements such as photosensors are arranged at equal intervals on a substrate (in the vertical direction), when laser 0 crosses a light-receiving base on which the photosensors are arranged in the vertical direction, the sensor elements in the portion that receives the laser are excited. By a controller (not shown) identifying which position sensor element is excited and causing the display unit (not shown) to indicate that position, the height position of the holding member that holds the light-receiver can be determined. That is, the principle of the light-receiver has a simple configuration as long as the controller can identify which sensor element is excited.

[0007] In addition, when the light-receiver is held by a reference pole provided in the vertical direction on a machine tool, the main body may sway as the machine tool moves.

[0008] Patent Document 1 below discloses that "to provide a control system and a control method capable of easily controlling the position of a leveling tool of a construction machine, the control system controls the position of the leveling tool of the construction machine according to a construction plan. The control system consists of three basic elements: a stationary tracking station 10, a computer 12 connected to the tracking station 10, and a tool control device 14 attached to the construction machine. The tracking station 10 measures the distance and azimuth (horizontal) angle 40 to a distant target 28 placed on the construction machine and communicates the position information to the computer 12. The computer 12 diagnoses the construction plan stored to determine which height is desired at that position, calculates the corresponding zenith (elevation) angle, and communicates the desired zenith angle 34 to the tracking station 12. The tracking station 10 positions the zenith reference laser beam in order at that zenith angle 34. The tool control device 14 detects the zenith reference laser beam and adjusts the leveling tool 50 with respect to the reference laser beam until the desired position is obtained."

[0009] Further, in paragraphs 0031 to 0032 of Patent Document 2 below, regarding a laser light detection device, it is disclosed that "As shown in FIG. 2, the laser light detection device 1 has a light receiving sensor 5 for detecting laser light P, and a display 6 for presenting to the operator on the construction machine 2 side the deviation from the appropriate height based on the detection result of the light receiving sensor 5. The light receiving sensor 5 is disposed at the front part of the laser light detection device 1. In the detection range of the light receiving sensor 5, an upper range R1 and a lower range R2 are disposed above and below the center C, respectively. Both ranges R1 and R2 have dimensions of approximately 10 cm. The laser light is sent from the left side to the right side in FIG. 2 and can enter the detection range of the light receiving sensor 5."

[0010] It can be determined that the light receiving sensors shown in Patent Document 2 are arranged at substantially intervals at the center, but there is no description regarding the diameter of the laser beam of a predetermined width scanned from the rotor.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0012] On the other hand, in a concrete leveling operation in which the above light receiver is arranged in an environment where the machine tool moves and the height is measured while detecting a certain height, the following problems have been pointed out.

[0013] 〔Laser Direction〕 Conventional light receivers can be left to the operator as long as they have a certain light-receiving angle because the operator aims them in the laser direction. However, when a light receiver is installed on a vertical reference pole attached to a moving machine tool, the laser direction cannot be determined, so it is necessary to support 360-degree light reception.

[0014] 〔Immediate responsiveness〕 When an operator operates a light receiver, even if it takes several hundred milliseconds to several seconds to determine the laser position, it is not a major problem. On the other hand, when laser light emitted from a laser is installed in a device, for example, a machine tool, and the moving direction and moving speed of the machine tool are controlled, depending on the application, the control content is determined by one irradiation coming at a 100-ms cycle. Therefore, immediate responsiveness is required for the processing of laser light reception.

[0015] 〔Sensitivity characteristics and removal of the influence of ambient light and noise〕 In the case of applications where an operator reads the numerical value displayed by a light receiver, even if it takes several hundred milliseconds to several seconds, it is not a major problem. Therefore, for example, even if the results of accumulating a laser irradiated at a 100-ms cycle multiple times are displayed, no actual harm will occur. For this reason, the ratio of the signal by the laser light to ambient light (sunlight that changes the irradiation position over time) and noise can be increased.

[0016] On the other hand, in a control system that requires immediate responsiveness, since it is necessary to accurately determine the position with one laser light reception, it is required to remove the influence of ambient light and noise while increasing the sensitivity.

[0017] Also, when a rotating laser is at a position 50 m away at 600 rpm, for example, the time to pass through a 5-mm photosensor is 1.6 μs, and it is necessary to accurately detect this for each irradiation.

[0018] 〔Accuracy and light-receiving width〕 For the light receiver operated by the operator, the light receiver mounted on the moving machine tool needs to have a larger light-receiving width. However, since the cost occupied by the light-receiving element (light-receiving sensor) in the light receiver is high, it is necessary to adopt a configuration that maintains the light-receiving accuracy for normal control of the machine tool and expands the light-receiving width while suppressing the cost.

[0019] In addition, the height accuracy required at the site where the machine tool moves is less than 1 mm (about 0.5 mm), while the laser light has a width of about 5 mm to 10 mm, and it is necessary to accurately detect the center position thereof. In particular, in a construction environment where sunlight is incident, if the influence of disturbance cannot be eliminated, it will hinder the construction involving height adjustment.

[0020] The present invention has been made to solve the above problems, and by adjusting the arrangement pattern of light-receiving elements that receive laser light scanned in rotation, in an environment susceptible to the influence of disturbance and in a construction environment where the machine tool moves, even when receiving laser light of a predetermined width, a laser light receiver, a level detection system, and a control method for the laser light receiver are provided that can significantly improve the accuracy of the detected height.

Means for Solving the Problems

[0021] The laser light receiver of the present invention that achieves the above object has the following configuration.

[0022] The laser light receiver according to the present invention is configured to receive laser light that is plane-scanned with a predetermined width on a substrate on which a plurality of light-receiving elements are arranged vertically according to a predetermined accuracy distribution. Further, the control method of the laser light receiver of the present invention that achieves the above object has the following configuration.

[0023] A control method for a laser receiver, in which laser light that is plane-scanned with a predetermined width is arranged symmetrically with respect to the vertical direction with the center position on a substrate on which a plurality of light-receiving elements are arranged vertically according to a predetermined accuracy distribution. The method includes: a detection step of detecting a signal level of any one of the light-receiving elements excited at a predetermined cycle; a determination step of determining whether the signal level of any one of the detected light-receiving elements exceeds a preset threshold value; a determination step of determining whether there are a plurality of light-receiving elements indicating a signal level exceeding the threshold value; an arithmetic step of calculating the area of adjacent overlapping light-receiving regions when it is determined that there are a plurality of light-receiving elements indicating a signal level exceeding the threshold value; and a determination step of determining the light-receiving position of the laser light from the centroid position based on the area of the light-receiving region as height information. characterized by comprising the same.

Effect of the Invention

[0024] According to the present invention, even when receiving laser light with a predetermined width in an environment susceptible to the influence of disturbances and in a construction environment where a machine tool moves, the accuracy of the detected height can be significantly improved.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Best Mode for Carrying Out the Invention

[0026] Next, the best mode for carrying out the present invention will be described with reference to the drawings.

[0027] <Explanation of System Configuration> 〔First Embodiment〕 Figs. 1 and 2 are diagrams showing an example of an automatic concrete floor construction system using the laser receiver according to this embodiment, and the cooperation with the rotary laser position measurement system described later will be detailed. It is a diagram showing an example of a concrete leveling processing system using the rotary laser system according to this embodiment.

[0028] Referring to Fig. 1, in the first step, steel bar assembly is performed at the location where the concrete floor 10 of the construction site such as a warehouse is to be constructed, and then fresh concrete is placed by a concrete pump truck. The concrete pumped from the piping of the pump truck is roughly leveled using a stirring rod or the like. Before placing the fresh concrete, various tests such as a slump test, an air content test, and a chloride content test are performed to confirm the properties of the fresh concrete.

[0029] In FIGS. 1 and 2, the first automatic steering device 200 includes a conveying unit 20 as a traveling means and a leveling and re-vibrating unit 30 detachably connected to the conveying unit 20. The conveying unit 20 has a housing 21, a toothed wheel (wheel) 23, a detachable auxiliary tire 24 detachably attached to the toothed wheel (wheel) 23 as an option, and a towing hook 27 for locking the leveling and re-vibrating unit 30 to the conveying unit 20.

[0030] The leveling and re-vibrating unit 30 has a vibration transmission bar 18, a vibration transmission rod, a re-vibration motor 12, a vibration blade 13, and a tapper 16 located in front of the vibration blade 13. Here, the vibration frequency of the vibration blade 13 is preferably 50 - 300 Hz and the vibration acceleration is 7G or more.

[0031] In the first step, the first automatic steering device 200 can be set to the "casting leveling mode (first working mode)" to perform casting leveling by remote control or automatic control. Conventionally, an operator performed the tamping work by inserting a rod-shaped vibrator into the fresh concrete while considering the insertion interval and insertion location based on experience. However, by performing casting leveling with the first automatic steering device 200, it is possible to suppress the work cost and improve the work efficiency.

[0032] <Second Step (Laser Screed Leveling)> As shown in FIG. 2, in the second step, the first automatic steering device 200 is switched to the "laser screed leveling mode (second working mode)" to automatically level the casting surface by remote control or automatic control. The first automatic steering device 200 rotates the oscillation shaft at a high speed to cause the vibration blade 13 to vibrate in a plane, thereby filling and tamping the concrete.

[0033] The first automatic leveling device 200 has support rods 42 and 43 facing each other in the width direction, and laser receivers 42a and 43a are respectively located at the tips of the support rods 42 and 43. Near the first automatic leveling device 200, a laser emitter 45 having a laser irradiation unit is arranged, and the level of the concrete floor surface 10 is monitored by an automatic level adjustment means composed of the laser emitter 45 and the laser receivers 42a and 43a.

[0034] Also, as described above, the first automatic leveling device 200 includes a tapper 16 for scraping the concrete floor surface 10 and a vibration blade 13 located behind the tapper 16 for applying planar vibration to the concrete floor surface 10 by a vibrator to level it. By removing air bubbles and air in the concrete through vibration tamping by the vibrator and increasing the density, cracking of the concrete floor surface 10 can be suppressed.

[0035] In conjunction with the automatic level adjustment means, scraping of the concrete floor surface 10 by the tapper 16 and tamping by the planar vibration of the vibration blade 13 are performed. That is, the first automatic leveling device 200 has a laser level measurement function by the automatic level adjustment means, a concrete scraping function by the tapper 16 driven in conjunction with the automatic level adjustment means, and a tamping function that vibrates in conjunction with the automatic level adjustment means.

[0036] In this way, since the first automatic leveling device 200 advances in the traveling direction while the automatic level adjustment means checks the horizontal level of the placement surface, the operator can always confirm the level and perform the work while maintaining a stable level. Therefore, instead of the leveling work that was conventionally done manually by plasterers, by performing automatic floor leveling with the first automatic leveling device 200, unevenness can be reduced, the level can be made uniform, workability can be improved, and dense concrete can be realized by the tamping effect caused by the vibration of the vibration blade 13.

[0037] FIG. 3 is a diagram for explaining the light receiving element arrays of the laser receivers 42a and 43a that constitute the rotary laser system showing this embodiment.

[0038] In FIG. 3, 500 is a substrate, and a plurality of light receiving elements PD that receive laser light of a predetermined width to be scanned are arranged on the substrate 500 according to a predetermined pattern following an accuracy distribution. More specifically, a plurality of light receiving elements PD that receive laser light of a predetermined width to be scanned are arranged at symmetric positions with respect to the axial direction following the vertical direction with the center position on the substrate 500 as a reference according to a predetermined pattern following an accuracy distribution.

[0039] In this embodiment, a case where the width of the laser light is 5 to 10 mm will be described. However, when the distance from the laser irradiator is short, the light does not spread and may hit narrower than 5 mm. Therefore, the width of the laser light is determined according to the distance relationship with the laser irradiator installed at the construction site.

[0040] In particular, in the vicinity of the center position on the substrate 500, a plurality of light receiving element rows PD1 and PD2 that are continuous at a predetermined pitch are arranged in parallel. The accuracy distribution is configured to form a distribution configuration with the center position as a high-precision region Z1 and sub-high-precision regions Z2, medium-precision regions Z3, and low-precision regions Z4. For the sake of explanation, no special reference numerals are attached to each light receiving element. Also, the number of light receiving elements is adjusted according to the balance with the cost.

[0041] In addition, for the plurality of light receiving element rows PD1 and PD2 arranged in parallel, the other light receiving element row PD2 is arranged on the substrate 500 in a staggered manner at a position where it receives the laser light passing through the scanning position that the one light receiving element row PD1 arranged on the substrate 500 does not receive.

[0042] Furthermore, the plurality of light receiving element rows PD1 and PD2 arranged in parallel are configured to be arranged on the substrate 500 in correspondence with the high-precision region Z1 of the accuracy distribution.

[0043] Thereby, while reducing the number of light receiving elements PD to be arranged on the substrate 500 shown in FIG. 3, it becomes possible to significantly improve the light receiving accuracy.

[0044] FIG. 4 is a plan view for explaining the arrangement of color filters F1 to F5 for reducing disturbance provided in the laser light receivers 42a and 43a shown in FIG. 3. In the present embodiment, the substrates 500-1 to 500-5 are arranged so as to form, for example, a pentagon with respect to the center O, and the maximum nas angle with the laser light incident on the color filters F1 to F5 occurs when the laser light abuts from the vertex direction.

[0045] Therefore, in the present embodiment, in order to suppress the number of substrates 500 while ensuring a certain level of light reception sensitivity, a configuration of five sheets is adopted so that the maximum angle is 36 degrees.

[0046] Thereby, the manufacturing cost of the laser light receivers 42a and 43a can be significantly reduced.

[0047] FIGS. 5 and 6 are diagrams for explaining an image of receiving laser light that scans the substrates 500-1 to 500-3 shown in FIG. 4.

[0048] In FIG. 5, for example, when it is composed of light receiving elements PD-1-1 to PD-1-5, PD-2-1 to PD-2-5, and PD-3-1 to PD-3-5, the light receiving elements at the same height of the substrates 500-1 to 500-3 are respectively connected, and the light receiving elements at the same height are regarded as one height detection sensor. For example, when the lower two light receiving elements receive laser light with a predetermined width to be scanned, it corresponds to a configuration example in which signals obtained by exciting the respective light receiving elements are A / D converted by the A / D conversion unit 603. In addition, in FIG. 6, the same components as those in FIG. 5 are denoted by the same reference numerals and the description thereof is omitted.

[0049] In this example, since the entire 360-degree circumference is regarded as one sensor, disturbance light from a direction different from the laser light may affect the light reception sensitivity of the laser light. For example, even when direct sunlight is received from the side opposite to the laser light, it is assumed that any one of the light receiving elements is excited depending on the amount of direct sunlight.

[0050] Note that, even if external light is received while any one of the substrates 500 is receiving normal laser light, the amount of voltage change shows a small value (refer to the laser light reception characteristics shown in FIG. 8).

[0051] FIG. 7 is a block diagram for explaining the configuration of the controllers of the laser receivers 42a and 43a shown in FIG. 3.

[0052] In FIG. 7, the controller CONT includes a power supply 605, and a predetermined voltage is applied to the substrate 500, the differential amplifier circuit 601, the peak hold circuit 602, and the A / D conversion unit 603 so as to show a predetermined operating potential.

[0053] Also, the controller CONT generates a synchronization signal for detecting which of the light receiving elements of the substrate 500 is excited every 10 ms, and comprehensively controls the substrate 500, the differential amplifier circuit 601, the peak hold circuit 602, and the A / D conversion unit 603.

[0054] Note that the controller CONT controls the operation of discharging the peak hold circuit 602 in order to detect the peak of the laser light received every 10 ms. The controller CONT includes a memory 604 and stores a program that follows the procedure shown in the flowchart described later.

[0055] Also, the A / D conversion unit 603 is configured to be able to output a peak value of 0 to 255 bits to the controller CONT by converting the analog signal output from the peak hold circuit 602 into, for example, an 8-bit digital signal.

[0056] Note that the threshold value set by the controller CONT can be adjusted so that the threshold value can be set within a range exceeding the intermediate value of the detectable level.

[0057] In order to reduce the disclosure of ambient light, analog switches SW1 and SW2 are provided between the substrate 500 and the A / D conversion unit 603 as shown in FIG. 6, and the controller CONT controls the ON / OFF of the analog switches, so that it is also possible to configure to electrically disconnect each substrate 500.

[0058] Also, in the drive control circuit of the laser light receivers 42a and 43a shown in FIG. 7, the controller CONT shuts off all the analog switches SW1 and SW2 (transitions from the ON state to the OFF state), selects them one by one, and controls the A / D conversion process by the A / D conversion unit 603, so that it becomes possible to capture the behavior of one substrate 500 affected by ambient light and noise, and since the S / N is improved, it is also possible to detect the scanned laser light with high sensitivity.

[0059] FIG. 8 is a timing chart for explaining the timing of the laser light received by the light receiving element arrays PD1 and PD2 shown in FIG. 3. The vertical axis represents the signal level (voltage) of the pulse signal by which the light receiving element receives and is excited by the laser light, and the horizontal axis represents time.

[0060] Note that the period of each pulse signal is 100 ms, and the equally spaced lines parallel to the vertical axis indicate the case where it is 10 ms.

[0061] Also, the continuously changing line in the lower level region than each pulse signal corresponds to the ambient light or noise incident on the light receiving element arrays PD1 and PD2.

[0062] In this example, the light receiving element is irradiated with laser light at a period of 100 ms, the controller CONT processes the light information and noise information received at 10 ms, and the controller CONT performs A / D conversion processing by the A / D conversion unit 603 at a period of 10 ms, thereby obtaining peak values at 10 ms intervals.

[0063] Thereby, the controller CONT can detect the level of the scanned laser light at the timing of receiving the laser light, and the level of the ambient light at other timings.

[0064] FIG. 9 is a diagram for explaining a process of determining a scanning center position when receiving laser light scanned in the high-precision region Z1 of the substrate 500 shown in FIG. 3.

[0065] (a) of FIG. 9 shows the scanning state of the laser light scanned in the high-precision region Z1 among the light-receiving elements of the substrate 500, and (b) of FIG. 9 shows a method by which the controller CONT performs arithmetic processing to determine the scanning position.

[0066] 〔Base level processing〕 Before starting this operation, as calibration, the controller CONT gives a moving average in the time direction to each light-receiving element arranged on the substrate 500, and holds the value of the base level of each light-receiving element in the memory 604 in the controller CONT.

[0067] Then, after starting this operation, when the controller CONT determines that the difference value between the sensor value (acquired as a signal level) obtained when newly receiving the scanned laser light and the base level for each light-receiving element stored in the memory 604 exceeds the threshold value, the controller CONT stores the sensor value in the memory 604 as a candidate for the received light level every 100 ms.

[0068] Next, when the controller CONT refers to the laser candidates of all the light-receiving elements stored in the memory 604 and determines that the laser light was not received at that timing, the controller CONT updates the base level of each light-receiving element including the A / D conversion value of the latest signal level.

[0069] When the operation cycle in the controller CONT is 10 ms and the moving average time of the base level is 100 ms, the controller CONT calculates the new base level based on the following formula (1). New base level = (Previous base level × 9 + Sensor value) / 10…(1)

[0070] Note that the controller CONT controls so as not to update the base level at the timing when it determines that the laser light has been received.

[0071] 〔Comparison Processing between Sensors on the Same Substrate〕 On a single substrate 500, light-receiving elements are arranged side by side so as to be arranged in the vertical direction (the direction perpendicular to the plane), and adjacent light-receiving elements are excited by laser light having a width (5 to 10 mm) and scanned. In particular, since the light-receiving element closer to the center of the laser light is strongly excited, the signal level reacts stronger than the level of ambient light.

[0072] Therefore, the controller CONT calculates the difference between the base level of each light-receiving element stored in the memory 604 and the signal level based on the laser light received by the light-receiving element for all the light-receiving elements, and determines whether it is a normal laser candidate as the laser light.

[0073] Next, the controller CONT extracts the light-receiving element showing the strongest value from the light-receiving elements to be processed as laser candidates among the light-receiving elements of the five substrates 500-1 to 500-5, and sets the substrate on which the light-receiving element is arranged as the current laser candidate substrate.

[0074] However, when the controller CONT determines that there is a light-receiving element showing a strong tendency at a distant position, since there is a possibility of noise, it executes an exception process of excluding the signal level of the light-receiving element from the candidates.

[0075] 〔Comparison Processing between Substrates〕 The controller CONT of the laser light receivers 42a and 43a composed of the five substrates 500-1 to 500-5 determines in the field from which direction the laser light is received. That is, on the same plane, depending on the direction of the laser light, there is a possibility that a plurality of substrates receive the laser light at the same time. Therefore, the light-receiving element that outputs a stronger and more characteristic signal level as the laser light is extracted.

[0076] Specifically, the controller CONT assigns points to the candidate substrates from the following two perspectives, and determines that the substrate with the highest point value (the signal levels output by the light-receiving elements of the other four substrates are false signals) should be the substrate to be focused on.

[0077] First, the controller CONT assigns points to the substrate indicating the light-receiving level of the light-receiving element (the value obtained by subtracting the base level of the light-receiving element from the sensor value of the light-receiving element) (the first perspective). This is because the substrate that receives the laser light more directly from the front shows the highest writing level.

[0078] Furthermore, the controller CONT assigns points to the substrate indicating the light-receiving level of the light-receiving element adjacent to the light-receiving element showing the maximum value (the second perspective).

[0079] This is because, as described above, the laser light is a light beam with a predetermined width, so the possibility of exciting a plurality of light-receiving elements increases.

[0080] Based on the point values considering the first and second perspectives, the controller CONT can finally identify one substrate that is receiving the laser light from among the substrates receiving the laser light.

[0081] FIG. 10 is a diagram showing an example of height adjustment of the laser receivers 42a and 43a and the rotary laser device showing this embodiment.

[0082] Instead of the structure in which the laser receivers 42a and 43a shown in FIG. 2 are set, when the laser receivers 42a and 43a are fixed to a pole that can be moved vertically by a cylinder 600, and the controller CONT senses that the laser light scanned from the laser emitter 45 is lower than the reference position, the controller CONT outputs a control signal for moving the cylinder 600 vertically upward by a predetermined amount.

[0083] As a result, the light-receiving positions of the laser light receivers 42a and 43a move upward to the reference position with respect to the plane, and height adjustment can be performed following the height set by the laser emitter 45.

[0084] FIG. 11 is a flowchart showing an example of a control method for the laser light receivers 42a and 43a showing the present embodiment. Note that (1) to (15) indicate each step, and each step is realized by a CPU (not shown) provided in the controller CONT expanding a program stored in the ROM into the RAM and executing it. Further, it is desirable to employ an EEPROM so that the program can be updated at any time according to the addition of function processing or the like.

[0085] First, when the controller CONT confirms that the power supply 605 is turned on (1), it initializes each part via the power supply line and the control line (2).

[0086] This initialization process also includes a process of resetting a memory (not shown). Next, the controller CONT starts a timer by a timer circuit (not shown) (3).

[0087] Then, when the controller CONT confirms that the time counted after the timer starts reaches 10 ms (4), the controller CONT causes the light-receiving element on the substrate 500 to receive the laser light (5), and the controller CONT applies a timing signal to the differential amplifier circuit 601 to amplify the detected signal level (6).

[0088] Next, when the controller CONT determines that the signal level excited by the received laser light is the peak hold output timing (7), it applies a timing signal for reading the signal level held in the peak hold circuit 602, and the A / D conversion unit 603 performs A / D conversion on the signal level (8), and causes the peak value data D1 to be held in the memory 604 (9).

[0089] Next, the controller CONT determines whether or not there are two or more light-receiving elements whose peak value data D1 exceeds a preset threshold TH (10). If it is determined that the peak value data D1 does not exceed the preset threshold TH and the number of light-receiving elements is two or less, the process returns to step (3).

[0090] On the other hand, in step (10), if the controller CONT determines that there are two or more light-receiving elements whose peak value data D1 exceeds the preset threshold TH, the controller CONT stores the peak value data D1 in the memory 604 (11). The controller CONT calculates the difference between the set height (the reference height at which the laser emitter 45 is scanning) and the peak value data D1 stored in the memory 604 (12).

[0091] In this embodiment, the case where the controller CONT determines that there are two or more light-receiving elements whose peak value data D1 exceeds the preset threshold TH is described. However, even when there is one light-receiving element, if the controller CONT determines that there is no other strong candidate, the controller CONT may be configured to include a process of determining it as laser light.

[0092] In particular, in the low-precision region Z4, since the interval between the light-receiving elements is wide, there are many cases where only one light-receiving element receives the laser light. Also, when there is one received laser light, the controller CONT calculates the sensor position as the center of gravity.

[0093] Next, the controller CONT determines the current height value (difference value) and outputs it to the machine tool as digital data (13).

[0094] Next, the controller CONT determines whether or not the measurement has ended based on whether or not it has received a control signal from the machine tool (15). If it is determined that it has received the signal, this process ends. If it is determined that it has not received the signal, the process returns to step (3) and this process is repeated.

[0095] Note that this step is an example according to the system configuration, and it is optional to combine additional processes between each step. For reversible steps, the steps may be executed after being swapped.

[0096] 〔Effect of the First Embodiment〕 According to this embodiment, even in a field environment affected by sunlight that moves over time, it is possible to eliminate the influence of disturbing light and accurately determine height information.

[0097] 〔Second Embodiment〕 In the above embodiment, the laser receivers 42a and 43a and their control device have been described. After the laser receivers 42a and 43a receive the laser light scanned from the laser emitter 45 having the laser irradiation unit shown in FIG. 2, the leveling process of the first automatic steering device 200 moving on the plane is executed by communicating with the control unit of the machine tool via the communication interface provided in the controller CONT.

[0098] FIG. 12 is a block diagram for explaining the control configuration of the level detection system showing this embodiment. The same components as those in FIG. 7 are denoted by the same reference numerals and their description is omitted.

[0099] In FIG. 12, reference numeral 1000 denotes a controller unit that comprehensively controls the leveling work of the concrete to be injected into the building structure based on the height information obtained from the laser reception control unit shown in FIG. 7. It is desirable that the communication interface employs a wireless interface that communicates according to a predetermined protocol according to the field environment.

[0100] 〔Effect of the Second Embodiment〕 According to this embodiment, even in a field environment affected by sunlight that moves over time, it is possible to eliminate the influence of disturbing light, accurately acquire height information, and efficiently perform a uniform concrete surface leveling operation.

[0101] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0102] The disclosure of the present invention described above can be summarized at least as the following matters.

[0103] (1) It is characterized in that a configuration is adopted in which laser light scanned in a plane with a predetermined width is received on a substrate on which a plurality of light receiving elements are arranged vertically according to a predetermined accuracy distribution.

[0104] (2) It is characterized in that a configuration is adopted in which laser light scanned in a plane with a predetermined width is arranged so as to be in a symmetric position with respect to the vertical direction with the center position on a substrate on which a plurality of light receiving elements are arranged vertically according to a predetermined accuracy distribution as a reference.

[0105] (3) It is characterized in that in the vicinity of the center position on the substrate, a plurality of light receiving element rows continuous at a predetermined pitch are arranged in parallel.

[0106] (4) It is characterized in that the accuracy distribution has a distribution configuration of high accuracy, quasi-high accuracy, medium accuracy, and low accuracy with the center position being high accuracy.

[0107] (5) It is characterized in that in the plurality of light receiving element rows arranged in parallel, the other light receiving element row is arranged in a staggered manner with respect to the substrate at a position where it receives laser light passing through a scanning position where one light receiving element row arranged on the substrate does not receive light.

[0108] (6) It is characterized in that the plurality of light receiving element rows arranged in parallel are arranged on the substrate in association with the high-accuracy region of the accuracy distribution.

[0109] When a laser beam with a predetermined width to be scanned scans over the light receiving elements, it is characterized by comprising a controller that calculates the excitation level of each light receiving element at predetermined intervals to determine the irradiation position of the laser beam.

[0110] (8) The controller is characterized in that it calculates the centroid position based on the excitation level of each light receiving element at predetermined intervals to determine the irradiation position of the laser beam.

[0111] (9) It is characterized in that a laser beam with a diameter having a predetermined width scans over the light receiving elements.

[0112] (10) The controller is characterized in that it communicates with a predetermined machine tool via a predetermined interface.

[0113] (11) The level detection system is characterized in that the laser receiver described in any one of (1) to (3) communicates with a predetermined machine tool via a predetermined interface.

[0114] (12) The predetermined machine tool is characterized by comprising a control unit that controls the leveling operation of the concrete poured into the building structure based on the height information obtained from the laser receiver.

[0115] A control method for a laser receiver, in which laser light that is plane-scanned with a predetermined width is arranged symmetrically with respect to the vertical direction with the center position on a substrate where a plurality of light-receiving elements are arranged vertically according to a predetermined accuracy distribution as a reference, comprising: a detection step of detecting a signal level of any one of the light-receiving elements excited at a predetermined cycle; a determination step of determining whether the signal level of any one of the detected light-receiving elements exceeds a preset threshold value; a determination step of determining whether there are a plurality of light-receiving elements indicating a signal level exceeding the threshold value; an arithmetic step of calculating the area of adjacent overlapping light-receiving regions when it is determined that there are a plurality of light-receiving elements indicating a signal level exceeding the threshold value; and a determination step of determining the light-receiving position of the laser light as height information from the centroid position based on the area of the light-receiving region.

Explanation of Signs

[0116] 42a Laser receiver 43a Laser receiver 45 Laser emitter 500 Substrate CONT Controller

Claims

1. A laser receiver, characterized in that a laser beam that is plane-scanned with a predetermined width is received on a substrate on which a plurality of light-receiving elements are arranged vertically according to a predetermined accuracy distribution.

2. A laser receiver, characterized in that a laser beam that is plane-scanned with a predetermined width is arranged such that it is symmetric with respect to the vertical direction with reference to the center position on a substrate on which a plurality of light-receiving elements are arranged vertically according to a predetermined accuracy distribution.

3. The laser receiver according to claim 2, characterized in that near the center position on the substrate, light-receiving element arrays that are continuous at a predetermined pitch are arranged in parallel.

4. The laser receiver according to any one of claims 1 to 3, characterized in that the accuracy distribution forms a distribution configuration with high accuracy at the center position and sub-high accuracy, medium accuracy, and low accuracy.

5. The laser receiver according to claim 3, characterized in that in the plurality of light-receiving element arrays arranged in parallel, the other light-receiving element array is arranged in a staggered manner with respect to the substrate at a position where it receives the laser beam that passes through a scanning position where one light-receiving element array arranged on the substrate does not receive light.

6. The laser receiver according to claim 3 or 4, characterized in that the plurality of light-receiving element arrays arranged in parallel are arranged on the substrate in association with the high-accuracy region of the accuracy distribution.

7. The laser receiver according to any one of claims 1 or 3, characterized in that when a laser beam with a predetermined width being scanned scans over the light-receiving elements, it is provided with a controller that calculates the excitation level of each light-receiving element every predetermined period to determine the irradiation position of the laser beam.

8. The laser receiver according to claim 7, characterized in that the controller calculates the centroid position based on the excitation level of each light-receiving element every predetermined period to determine the irradiation position of the laser beam.

9. The laser receiver according to any one of claims 1 to 3, characterized in that it has a configuration in which a laser beam with a diameter having a predetermined width scans over the light-receiving elements.

10. The laser receiver according to claim 7, characterized in that the controller communicates with a predetermined machine tool via a predetermined interface.

11. A level detection system, characterized in that the laser receiver according to any one of claims 1 to 3 communicates with a predetermined machine tool via a predetermined interface.

12. The leveling detection system according to claim 11, wherein the predetermined machine tool includes a control unit that controls the leveling operation of the concrete poured into the building structure based on the height information acquired from the laser receiver.

13. A control method for a laser receiver in which laser light scanned in a plane with a predetermined width is arranged symmetrically with respect to the vertical direction with reference to the center position on a substrate on which a plurality of light receiving elements are arranged vertically according to a predetermined accuracy distribution, a detecting step of detecting a signal level of any one of the light receiving elements excited at a predetermined period; a determining step of determining whether the signal level of any one of the detected light receiving elements exceeds a preset threshold value; a determining step of determining whether there are a plurality of light receiving elements indicating a signal level exceeding the threshold value; an arithmetic step of calculating the area of adjacent overlapping light receiving regions when it is determined that there are a plurality of light receiving elements indicating a signal level exceeding the threshold value; a determining step of determining the light receiving position of the laser light as height information from the centroid position based on the area of the light receiving region; A control method for a laser receiver, comprising:

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