Industrial vehicle

Abstract

To contribute to reduction of a burden on a worker and shortening of a construction period at a construction site.SOLUTION: A positioning unit 70 for satellite positioning mounted on an upper turning body 12 of a pile driver has a rail-like fixed base 82 fixed to the upper turning body 12, and a first antenna 71 is provided at one end of the fixed base 82. The fixed base 82 extends in the width direction of the upper swing structure 12, and the movable base 83 is assembled to the fixed base 82 so as to protrude from the other end portion of the fixed base 82. The second antenna 72 is provided in a portion of the movable base 83 protruding from the fixed base 82. The positioning unit 70 has a motor 85 for sliding the movable base 83 along the fixed base 82. The motor 85 is connected to a controller of the pile driver, and the controller is provided with an inter-antenna distance changing unit that changes the distance between the first antenna 71 and the second antenna 72 by driving and controlling the motor 85.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an industrial vehicle. [Background technology]

[0002] At construction sites where steel pipe piles are buried or ground improvement work is carried out, the construction location is determined in advance by surveying, and during construction, industrial vehicles such as pile drivers are guided to the construction location by an operator (see, for example, Patent Document 1).

[0003] In recent years, construction position guidance systems have been proposed in which an industrial vehicle is equipped with a satellite positioning antenna capable of receiving radio waves from a satellite, and the industrial vehicle is automatically guided to a construction position. For example, the construction position guidance system shown in Patent Document 2 is designed to be able to properly exercise its guidance function by mounting two satellite positioning antennas on the industrial vehicle and determining the position and orientation of the pile driver (specifically, the upper rotating body) by calculation from the relative positions of the satellite positioning antennas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-6880 [Patent Document 2] Japanese Patent Publication No. 2022-191514 Summary of the Invention [Problem to be solved by the invention]

[0005] Industrial vehicles are used in a variety of locations, including mountainous regions and urban areas. Therefore, when multiple satellite positioning antennas are used, fixing the positions of those satellite positioning antennas can reduce the radio wave reception sensitivity, depending on the situation. Furthermore, some industrial vehicles are equipped with large structures (e.g., a leader or auger screw in a pile driver), and the influence of these structures can reduce reception sensitivity. There is a concern that reduced reception sensitivity could hinder the effective use of the above-mentioned guidance function. In this regard, such concerns can be effectively alleviated by configuring the satellite positioning antennas so that the operator can manually change their relative positions.

[0006] However, the radio wave reception conditions of a satellite positioning antenna may change due to the movement or shape of the industrial vehicle, and it is expected that the position of the satellite positioning antenna will need to be adjusted frequently to maintain appropriate reception conditions. Because the satellite positioning antenna needs to receive radio waves from the satellite, its placement is likely to be limited to locations with few or no obstructions, such as the top of the vehicle. This means that workers must climb onto the industrial vehicle each time they need to make adjustments, increasing their workload. Performing the adjustment while taking safety into consideration increases the work time. This raises concerns that this may hinder efforts to shorten construction periods. Thus, there is still room for improvement in the configuration of satellite positioning antennas mounted on industrial vehicles in order to reduce worker burden and shorten construction periods.

[0007] The present invention has been made in consideration of the above-mentioned problems, and its main object is to contribute to reducing the burden on workers at construction sites and shortening construction periods. [Means for solving the problem]

[0008] The first invention is an industrial vehicle equipped with multiple satellite positioning antennas capable of receiving radio waves from satellites, and is equipped with a drive mechanism that varies the relative distance between the satellite positioning antennas, and a drive control unit that controls the drive mechanism.

[0009] The second invention is an industrial vehicle equipped with multiple satellite positioning antennas capable of receiving radio waves from satellites, and is equipped with a drive mechanism that changes the positional relationship of the satellite positioning antennas, and a drive control unit that controls the drive mechanism. [Effects of the Invention]

[0010] According to the first and second inventions, since a drive mechanism that changes the positional relationship (relative distance) of the satellite positioning antenna and a drive control unit that controls the drive mechanism are provided, there is no need to manually change the positional relationship (relative distance) by climbing onto the industrial vehicle, etc. Even if the reception environment changes due to the movement or shape change of the industrial vehicle, the positional relationship of the satellite positioning antenna can be easily adjusted accordingly, which contributes to reducing the burden on workers at the construction site and shortening the construction period. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a side view of the pile driver according to the first embodiment. [Figure 2] FIG. 2 is an enlarged view of a portion of FIG. 1 showing the base machine. [Figure 3] (a) Block diagram showing the electrical configuration of the pile driver, (b1) Schematic diagram showing a method for calculating the rotation angle, (b2) Schematic diagram showing a method for calculating the azimuth angle. [Figure 4] Schematic diagram showing a positioning unit. [Figure 5] 1A is a flowchart showing a process for changing the distance between antennas, and FIG. 1B is a schematic diagram showing the change conditions. [Figure 6] 10 is a timing chart showing a flow of changing the distance between antennas. [Figure 7] FIG. 10A is a schematic diagram showing a positioning unit according to a second embodiment, and FIG. 10B is a schematic diagram showing a positioning unit according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] First Embodiment A first embodiment of the present invention will be described below with reference to the drawings. First, the basic structure of a pile driver 10 will be described with reference to Figs. 1 and 2.

[0013] As shown in Figure 1, the pile driver 10 is equipped with a base machine 13 consisting of a lower traveling body 11 equipped with a pair of left and right crawlers 21 as a traveling device, and an upper rotating body 12 that is provided above the lower traveling body 11 and can rotate horizontally (left and right). A leader 15 is disposed in front of the upper rotating body 12, and in front of the leader 15 are provided an auger screw 16 and an auger 17 that can rise and fall along the leader 15 and rotates the auger screw 16.

[0014] The upper rotating body 12 is provided with a pair of left and right backstays 31 that support the leader 15 in the construction position (upright position) from the rear side of the upper rotating body 12, and support stays that support the leader 15 in the transportation position (dead position) on the rear side of the upper rotating body 12. In addition to the backstays 31 and support stays, the upper rotating body 12 is also provided with an operator's cab 35, a machine room 36, a gantry 37, a counterweight 38, etc. (see Figure 2).

[0015] The driver's cab 35 is equipped with devices such as an operation unit and a display for performing various operations such as traveling and turning, and these operation units are connected to a controller 50 (see FIG. 3(a)) that performs various controls related to the pile driver 10. The vehicle control mode by the vehicle control unit 51 of the controller 50 is provided with a manual driving mode in which the movement, turning, etc. of the pile driver 10 is controlled based on manual operation by the operator, and an automatic driving mode in which the pile driver 10 is controlled to move to the planned construction position (planned pile burying position) based on preset construction plan information, vehicle position information, turning angle information, etc., and these manual driving mode and automatic driving mode can be switched based on operation by the operator. Here, a supplementary explanation will be given of automatic driving in the automatic driving mode.

[0016] As shown in FIG. 3(a), the controller 50 is connected to a communication unit 61 that can communicate with a data server 63 on a network 62. Various data, such as the control program and the construction plan information, can be downloaded via the network 62. The construction plan information is input into a computer in the office in advance based on a construction plan prepared by investigating the location and soil quality of the construction site. It includes pile numbers and various construction target values ​​associated with the pile numbers, such as depth, feed speed, rotation speed, and cement milk flow rate. The construction plan information is input by inputting pile position data in comparison with the construction drawings. Specifically, the planned pile installation positions are specified in two-dimensional coordinates as relative positions (distances) from the origin of the coordinate system. Each pile number is also associated with an approach angle for the pile driver 10 to approach the installation position, taking into account the pile installation order. The created construction plan information is then uploaded to the data server 63 along with location information for the construction site address, the model number of the pile driver 10 to be installed, and vehicle exterior information. In addition, a construction management program for the construction method to be implemented based on the construction plan information, such as the precast pile method, the cast-in-place pile method, or the ground improvement method, and data on the setting parameters of the construction management program are also created and uploaded to the data server 63.

[0017] The vehicle position information described above is acquired by a positioning unit 70 (see FIG. 2) disposed at the rear of the upper rotating body 12 (more specifically, on the top surface of the machine room 36) using well-known GNSS (Global Navigation Satellite System) technology. Specifically, the positioning unit 70 includes GNSS antennas 71 and 72 (corresponding to "satellite positioning antennas") disposed at a distance from each other at the rear of the upper rotating body 12 of the pile driver 10, and receivers 73 and 74 connected to the GNSS antennas 71 and 72, and is capable of receiving radio waves from GNSS satellites 65.

[0018] The receivers 73, 74 are connected to the controller 50, and the positioning unit 52 of the controller 50 acquires latitude and longitude information (position information or coordinate information) of the GNSS antennas 71, 72, which changes as the pile driver 10 moves or rotates, and determines the orientation and position of the upper rotating body 12 (pile driver 10) by calculation based on the relative positions of the two GNSS antennas 71, 72.

[0019] In addition, during the process of moving to the planned pile burying position, the orientation of the lower traveling body 11 and the orientation of the upper rotating body 12 match, and the orientation determined by calculation is the orientation of the pile driver 10. After reaching the planned pile burying position, the upper rotating body 12 rotates to perform position adjustments, etc. At this time, the orientation determined by calculation is the orientation of the upper rotating body 12. In other words, it can be said that the positioning unit 52 is configured to calculate the azimuth angle of the pile driver 10 based on the latitude and longitude information while the pile driver 10 is traveling, and to calculate the slewing angle (or azimuth angle) of the upper rotating body 12 based on the latitude and longitude information after the pile driver 10 arrives at the planned pile burying position.

[0020] The controller 50 is also connected to a vehicle body tilt sensor for detecting the tilt angle of the vehicle body and a leader tilt sensor for detecting the tilt angle of the leader 15, and takes into account tilt information (posture) acquired from these sensors to identify the position of the central axis of the auger screw 16 on the ground, i.e., the pile core position. The vehicle control unit 51 of the controller 50 then moves the pile driver 10 along the set travel path to the planned pile burying position, thereby aligning the pile core position. In other words, it controls the travel of the lower traveling body 11 and the rotation of the upper rotating body 12 so that the pile core position coincides with the planned pile burying position.

[0021] Here, with reference to Figures 3(b1) and (b2), a supplementary explanation will be given of the outline of the calculation process of the rotation angle and azimuth angle that is executed periodically (for example, every 100 msec) by the positioning unit 52 of the controller 50. In the example shown in Figures 3(b1) and (b2), the upper rotating body 12 rotates clockwise when viewed from above (in a plan view). For convenience, in the following explanation, the GNSS antenna 71 will also be referred to as the "first antenna 71," and the GNSS antenna 72 will also be referred to as the "second antenna 72."

[0022] When calculating the rotation angle of the upper rotating body 12, the latitude and longitude information acquired from the positioning unit 70 is first converted into planar rectangular coordinates (XY coordinates). In the example shown in FIG. 3(b1), the first antenna 71 moves from coordinate P1 to coordinate P1', and the second antenna 72 moves from coordinate P2 to coordinate P2'. The angle α formed between the virtual line LN passing through the previous coordinates P1 and P2 and the virtual line LN' passing through the current coordinates P1' and P2' is the current rotation angle. In other words, the angle of rotation between the intervals of the calculation process can be calculated from the change in the coordinates of each antenna 71, 72. Then, the current rotation angle is calculated based on the default (rotation angle = 0°) based on the past calculation history and the current calculation result.

[0023] On the other hand, when calculating the azimuth angle of the pile driver 10 (upper rotating body 12), as shown in FIG. 3(b2), the angle β formed between a reference line DL passing through one of the current coordinate P1' (current position of the first antenna 71) and coordinate P2' (current position of the second antenna 72) and an imaginary line LN' passing through these coordinates P1' and P2' is calculated. In FIG. 3(b2), a line extending north-south is set as the reference line DL, assuming that the pile driver 10 will move north toward the target burial position. The angle β formed between this reference line DL and imaginary line LN' is the azimuth angle of the pile driver 10.

[0024] In this way, disposing the positioning unit 70 on the upper rotating body 12 instead of the lower running body 11 has the technical significance of contributing to simplifying the configuration for identifying the orientation (swing angle or azimuth angle) of the upper rotating body 12 and the orientation (azimuth angle) of the pile driver 10. Furthermore, compared to a configuration in which orientation is detected by a mechanism that generates physical contact, such as an encoder, this is advantageous in terms of suppressing the occurrence of malfunctions and facilitating maintenance.

[0025] However, when two GNSS antennas 71, 72 are used in combination, errors may increase in calculation of the turning angle, etc., depending on the relative positions of the GNSS antennas 71, 72, i.e., the relative distance between them. In particular, considering that the pile driver 10 is equipped with a large-mass structure called the reader 15 at the front of the vehicle and that piles are driven in a variety of locations, including urban areas, fixing the positions of the GNSS antennas 71, 72 may reduce the accuracy of calculation of the turning angle, etc., depending on the situation.

[0026] Here, for example, if the positions of the GNSS antennas 71 and 72 could be manually adjusted at the construction site, the above-mentioned concerns regarding accuracy could be alleviated to some extent. However, the need for workers to climb onto the upper rotating body 12 each time an adjustment is made can increase the workload. Furthermore, there is a concern that the increased work time required to perform the work while taking safety into consideration could hinder efforts to shorten the construction period. One of the features of this embodiment is that it takes such circumstances into consideration. Specifically, the positioning unit 70 is provided with an antenna distance change mechanism 81 as a positional relationship change mechanism that changes the positional relationship between the GNSS antennas 71 and 72, and the controller 50 is provided with a reception status monitoring unit 53 that monitors the reception status of the GNSS antennas 71 and 72, and an antenna distance change unit 54 that drives and controls the antenna distance change mechanism 81 based on the monitoring results of the reception status monitoring unit 53. In this embodiment, the antenna distance change mechanism 81 corresponds to the “drive mechanism,” the reception status monitoring unit 53 corresponds to the “monitoring unit,” and the antenna distance change unit 54 corresponds to the “drive control unit.” Hereinafter, the antenna distance change mechanism 81 will be described first with reference to FIG. 4.

[0027] The antenna distance change mechanism 81 has a fixed base 82 fixed to the upper surface of the upper rotating body 12. The fixed base 82 is rail-shaped and extends in the width direction of the pile driver 10 (upper rotating body 12), and the first antenna 71 is disposed at one end of the fixed base 82. A movable base 83 is attached to the fixed base 82 so as to protrude from the other end of the fixed base 82. The movable base 83 is also rail-shaped and extends in the longitudinal direction of the fixed base 82, and the second antenna 72 is disposed at the part protruding from the fixed base 82.

[0028] The movable base 83 is assembled to the fixed base 82 so as to be slidable relative to the fixed base 82, and the fixed base 82 is formed with a regulating portion 84 (more specifically, a guide groove) that regulates the sliding direction of the movable base 83 so that it is the same as the longitudinal direction of the fixed base 82, i.e., the width direction of the upper rotating body 12. The fixed base 82 also has a motor 85 that is an actuator for sliding the movable base 83 in the longitudinal direction. The motor 85 is connected to the controller 50 and operates in response to a drive signal from the antenna distance change unit 54 of the controller 50. As a result, the antenna distance change unit 54 changes the sliding position of the movable base 83, i.e., the relative distance between the first antenna 71 and the second antenna 72 (hereinafter also referred to as the antenna distance).

[0029] The mechanism (linear guide mechanism) for changing the distance between the antennas is arbitrary, and it is preferable to use, for example, a ball screw, a rack and pinion, a linear guide, or the like.

[0030] In the positioning unit 70 shown in this embodiment, the distance between the antennas can be switched in multiple stages (for example, 10 stages). In the following description, the states of the positioning unit 70 will be appropriately distinguished as a first state LV1 (see FIG. 4(a)), a second state LV2, a third state LV3, a fourth state LV4, a fifth state LV5, ..., and a tenth state LV10 (see FIG. 4(b)) in order of increasing distance between the antennas. In the seventh state LV7 to the tenth state LV10, the movable base 83 (second antenna 72) is positioned so as to protrude from the upper rotating body 12 (outside the vehicle), whereas in the first state LV1 to the sixth state LV6, the second antenna 72 is positioned directly above the upper rotating body 12 (inside the vehicle), preventing the movable base 83 (second antenna 72) from protruding from the upper rotating body 12. In this embodiment, LV1 is the state in which the antennas are at the shortest distance, and LV10 is the state in which the distance between the antennas is at the longest distance, but the state in which the distance between the antennas is at the longest distance may be any integer other than LV10 (for example, 20, which allows the distance between the antennas to be switched in 20 steps).

[0031] In the method shown in Figures 3(b1) and 3(b2), increasing the antenna distance is advantageous in reducing errors in calculating the rotation angle (direction). This is because, when defining the virtual line from the coordinates of the two GNSS antennas 71 and 72, the influence of coordinate misalignment on the slope of the virtual line decreases as the distance between the two coordinates increases. However, increasing the antenna distance and causing the positioning unit 70 to extend beyond the upper rotating body 12 to the outside of the vehicle is disadvantageous in preventing contact between the positioning unit 70 and other construction machinery, facilities, etc. In this embodiment, a design is made to prevent the above-mentioned contact (keep the positioning unit 70 as small as possible) while improving the radio wave reception environment by calculating the rotation angle (direction). Below, the configuration related to this design, i.e., the antenna distance change process executed periodically (every 100 msec) by the antenna distance change unit 54 of the controller 50, is described with reference to Figure 5. Fig. 5(a) is a flowchart showing the process for changing the distance between antennas, and Fig. 5(b) is a schematic diagram showing the conditions for changing the position. Note that the process for changing the distance between antennas can be configured to be executed periodically, or can be configured to be executed when a specific execution condition is met, such as when the pile driver 10 is started, when the pile driver 10 is switched to automatic operation mode, when position adjustment by rotating the upper rotating body 12 begins, or when a user operates the pile driver.

[0032] In the antenna distance change process, first, it is determined whether or not an operation to change the antenna distance is in progress based on the control status of the motor 85 (S101). If an operation to change the antenna distance is in progress (S101: YES), the change process is terminated. If an operation to change the antenna distance is not in progress (S101: NO), it is determined whether or not the reception status of the positioning unit 70 (receivers 73, 74) is “FIX” based on the monitoring results of the reception status monitor 53 (S102). If the reception status is “FIX,” it is determined whether or not the number of GNSS satellites 65 (hereinafter also referred to as “receiving satellites”) from which radio waves are received for the first antenna 71 and the second antenna 72 is equal to or greater than a predetermined number (10 in this embodiment) (S103). The number of receiving satellites has a significant effect on the radio wave reception status, so in this embodiment, the number of receiving satellites is used as one indicator for understanding the reception status.

[0033] The reception status is classified into the four types mentioned above, "FIX," "FLOAT," "Unlocated," and "Not Received," and in this embodiment, the condition is limited to being met only when it is "FIX," but this does not deny a configuration in which the condition is met also when it is "FLOAT."

[0034] A larger number of receiving satellites is preferable for improving the accuracy of identifying coordinates, i.e., the accuracy of calculating the orientation described above. However, if there is a bias in the positions of the receiving satellites, the effect of improving calculation accuracy will not be fully realized. For example, the calculation accuracy will be higher if the receiving satellites are scattered over a wider area as viewed from the pile driver 10 (at least 1 / 8 or more of the entire circumference of the pile driver, ideally roughly evenly around the entire circumference of the pile driver 10). On the other hand, if the receiving satellites are biased in a certain direction, the calculation accuracy will be low even if there are a large number of receiving satellites. DOP (Dilution of Precision) is an index that expresses this bias in the placement of receiving satellites. In this embodiment, this DOP (more specifically, HDOP) value is used as another index for understanding the reception status of radio waves from GNSS satellites 65. Note that the HDOP value will be small if the bias in the positions of the receiving satellites is small, and will be large if the bias in the positions is large.

[0035] Therefore, if the number of reception satellites reaches the predetermined number (S103: YES), it is determined whether the HDOP value is equal to or less than a reference value based on the monitoring results by the reception status monitoring unit 53 (S104). If the HDOP value is equal to or less than the reference value, a release process (operation restriction release process) is executed to release the operation restrictions on travel, rotation, etc. (S105). In this embodiment, if the reception status is inappropriate during the autonomous driving mode, i.e., if the reception status is not "FIX," if the number of reception satellites is less than the predetermined number, or if the HDOP value exceeds the reference value, the operation of the pile driver 10, such as travel and rotation, is restricted in consideration of safety, etc. In the operation restriction release process, the operation restrictions are released based on whether the conditions of S102 to S104 are met, i.e., if the reception status is appropriate.

[0036] Thereafter, it is determined whether the shortening restriction period for restricting shortening of the antenna distance has elapsed (S106). If the shortening restriction period has not elapsed (S106: YES), the change process is terminated. On the other hand, if the shortening restriction period has elapsed (S106: NO), the shortening process is executed to shorten the antenna distance (S107), and after setting the shortening restriction period (S108), the change process is terminated. By setting the shortening restriction period, shortening of the antenna distance is restricted for a certain period (for example, 600 seconds).

[0037] In the shortening process, the motor 85 is controlled and driven to shorten the antenna distance by one step from the current antenna distance. For example, when the state is the tenth state LV10, the motor 85 is controlled and driven to change to the ninth state LV9, and when the state is the ninth state LV9, the motor 85 is controlled and driven to change to the eighth state LV8. Note that when the state is the first state LV1, the first state LV1 is maintained.

[0038] If any of the conditions related to the reception status is not met (see FIG. 5(b)), that is, if the radio wave reception status is inappropriate (NO in any of S102 to S104), an operation restriction process is executed (S109) to restrict operations such as traveling and turning. As a result, the pile driver 10 comes to a halt (stationary). Thereafter, an operation to increase the distance between the antennas is executed (S110), and after a shortened restriction period is set (S107), this change process is terminated.

[0039] In the enlargement process, the motor 85 is controlled and driven to enlarge the antenna distance by one step from the current antenna distance. For example, when the state is the first state LV1, the motor 85 is controlled and driven to change to the second state LV2, and when the state is the second state LV2, the motor 85 is controlled and driven to change to the third state LV3. Note that when the state is the tenth state LV10, the tenth state LV10 is maintained.

[0040] Next, the flow of changing the antenna distance will be described with reference to the timing chart in Fig. 6. In the example shown in Fig. 6, the reception status is "FIX."

[0041] In the example shown in FIG. 6 , automatic operation of the pile driver 10 begins at time t1. At this time, the positioning unit 70 is in the first state LV1, where the antenna distance is the shortest, and both the operation restriction and the reduction restriction described above are enabled. In the first state LV1, the number of receiving satellites is equal to or greater than the predetermined number (10), but the HDOP value exceeds the reference value, resulting in an inappropriate reception condition. Therefore, an attempt is made to improve the communication conditions by changing the relative positions of the GNSS antennas 71 and 72. Specifically, the antenna distance is increased. At time t2, after the positioning unit 70 has entered the sixth state LV6 after repeated increases in the antenna distance, the HDOP value falls below the reference value, resulting in an appropriate communication condition. Immediately thereafter, at time t3 (the timing when the antenna distance change process is executed), the operation restriction of the pile driver 10 is released under the conditions that the reception status is set to "FIX," the number of receiving satellites is equal to or greater than the predetermined number, and the HDOP value is equal to or less than the reference value. This allows the pile driver 10 to begin traveling in automatic operation. In other words, it can be said that automatic tuning (adjustment) of the positioning unit 70 is carried out between timing t1 when automatic driving starts and timing t3.

[0042] At time t4 during autonomous driving, the communication conditions deteriorate, causing the HDOP value to exceed the reference value. Immediately thereafter, at time t5 (when the process for changing the antenna distance is executed), the operation restriction of the pile driver 10 is activated on the condition that the HDOP value exceeds the reference value. As a result, the pile driver 10 stops (parks) while traveling. As the communication conditions deteriorate, at time t5, the positioning unit 70 switches from the sixth state LV6 to the seventh state LV7, and the antenna distance is increased. As a result, part of the positioning unit 70 protrudes outside the vehicle.

[0043] Since the reception condition is not sufficiently improved even after the positioning unit 70 is switched to the seventh state LV7, the positioning unit 70 is switched from the seventh state LV7 to the eighth state LV8 at the next timing t6, and the antenna distance is further increased. As a result, the positioning unit 70 protrudes more outward from the vehicle.

[0044] At the subsequent timing t7, the HDOP value falls below the reference value, and immediately thereafter at timing t8 (when the process for changing the antenna distance is executed), the operational restrictions on the pile driver 10 are lifted under the conditions that the reception status is "FIX," the number of reception satellites is equal to or greater than a predetermined number, and the HDOP value is below the reference value. This allows the pile driver 10 to resume traveling in automatic operation. In other words, it can be said that retuning (readjustment) of the positioning unit 70 is performed from timing t5 to timing t8.

[0045] When the antenna distance is changed at timing t6, the count of the aforementioned shortening restriction period begins. At timing t9, the shortening restriction period has elapsed and the shortening restriction has been lifted. Immediately thereafter, at timing t10 ​​(the timing at which the antenna distance change process is executed), the shortening restriction has been lifted and the reception conditions have been maintained at an appropriate level, so the positioning unit 70 switches from the eighth state LV8 to the seventh state LV7, and the antenna distance is shortened. In other words, if the communication conditions remain appropriate and the shortening restriction period has elapsed without the antenna distance being increased, an attempt is made to shorten the antenna distance. In this case, the shortening restriction period corresponds to the "predetermined period."

[0046] When the antenna distance is changed at time t10, the count of the shortening restriction period starts again. At time t11, the shortening restriction period has elapsed and the shortening restriction is lifted. At time t12 immediately thereafter (when the antenna distance change process is executed), the shortening restriction has been lifted and the reception conditions are maintained appropriately, so the positioning unit 70 switches from the seventh state LV7 to the sixth state LV6, and the antenna distance is shortened. This prevents the positioning unit 70 from protruding outside the vehicle.

[0047] According to the first embodiment described above in detail, the following excellent effects can be expected.

[0048] When the pile driver 10 is operated in the automatic operation mode, the positioning unit 70 and the controller 50 automatically adjust (tune) the relative positions of the GNSS antennas 71, 72 so that radio wave reception conditions are optimal. This allows construction to begin promptly. The specifications of the pile driver 10, such as the attached equipment, may vary depending on the construction site and construction content. Although differences in specifications may cause differences in radio wave reception conditions, the configuration shown in this embodiment can appropriately accommodate such differences because the positioning unit 70 is automatically adjusted to match the pile driver 10 on which it is installed.

[0049] While the pile driver 10 is being guided to the target burial location, the reception environment may change. The relative positions of the GNSS antennas 71, 72 are automatically adjusted to accommodate such changes in the reception environment, eliminating the need for workers to manually adjust the positions of the GNSS antennas 71, 72 each time the reception environment changes. This is advantageous for reducing the burden on workers at the construction site and shortening the construction period. In particular, the pile driver 10 is large, and if the positioning unit 70 is installed on its upper surface to improve the communication environment, access to the positioning unit 70 becomes difficult. In other words, accessing the positioning unit 70 requires climbing onto the pile driver 10. In light of these circumstances, the above-described configuration, in which the positioning unit 70 is automatically adjusted without requiring access, significantly reduces the burden on workers.

[0050] Increasing the antenna distance in the positioning unit 70 is expected to improve communication accuracy. However, at construction sites, industrial vehicles other than the pile driver 10 are used, and various equipment is installed. Therefore, having the positioning unit 70 protrude outside the pile driver 10 in order to increase the antenna distance is undesirable in terms of preventing contact with other industrial vehicles, etc. In this regard, the positioning unit 70 shown in this embodiment is configured to attempt to shorten the antenna distance if the reception conditions are appropriate, and the antenna distance is adjusted to minimize the antenna distance while ensuring appropriate reception conditions. This configuration reduces the chances that the positioning unit 70 will remain protruding outside the vehicle, which is preferable in terms of preventing contact with other industrial vehicles, etc.

[0051] If the radio wave reception conditions deteriorate and become inappropriate, the antenna distance is quickly increased. Even if the reception conditions become appropriate after increasing the antenna distance, an attempt to shorten the antenna distance is not made immediately, but rather the shortening is restricted for a certain period of time. In other words, once the reception conditions become appropriate, the antenna distance is fixed for a certain period of time. This configuration reduces the chances that the operation of the pile driver 10 will be interrupted due to a deterioration in communication conditions.

[0052] Furthermore, even if the inter-antenna distance is shortened, the next shortening is restricted for a certain period of time. Repeated shortening of the inter-antenna distance is likely to eventually result in inadequate reception, but restricting the next shortening as described above makes it less likely that repeated shortening will result in frequent restrictions on the operation of the pile driver 10.

[0053] If the communication conditions become inappropriate as a result of shortening the antenna distance, the antenna distance may be quickly increased, while the operational restriction of the pile driver 10 may be suspended until it is confirmed that the increased distance improves the communication conditions. With such a configuration, it is possible to prevent the function of shortening the antenna distance from becoming a factor that frequently restricts the operation of the pile driver 10 during automatic operation.

[0054] <Second embodiment> In the first embodiment, the antenna distance is changed by changing the position of the second antenna 72. In this embodiment, the specific configuration for changing the antenna distance is different from that of the first embodiment. Hereinafter, with reference to FIG. 7(a), the positioning unit 70X in this embodiment will be described, focusing on the differences from the positioning unit 70 shown in the first embodiment. Note that the description of the same configuration as the positioning unit 70 will be omitted as appropriate.

[0055] The positioning unit 70X (antenna distance change mechanism 81X) includes a fixed base 82X fixed to the top surface of the upper rotating body 12 (machine room 36) and a pair of left and right movable bases 83aX, 83bX attached to the fixed base 82X. The left movable base 83aX (hereinafter referred to as the first movable base 83aX) extends leftward from the fixed base 82X, with the first antenna 71 disposed on the extending portion. The right movable base 83bX (hereinafter referred to as the second movable base 83bX) extends rightward from the fixed base 82X, with the second antenna 72 disposed on the extending portion. The first movable base 83aX and the second movable base 83bX are attached to the fixed base 82X so as to be slidable, and the sliding directions of the first movable base 83aX and the second movable base 83bX are determined by a determining portion 84X so that they slide in opposite directions. In addition, the fixed base 82X is provided with a motor 85aX which is an actuator for the first movable base 83aX and a motor 85bX which is an actuator for the second movable base 83bX, so that the positions of the first antenna 71 and the second antenna 72 can be changed individually.

[0056] The antenna distance change unit 54 of the controller 50 controls the change of the antenna distance in two ways: one in which the distance between the antennas is enlarged / shortened by making the sliding amount of the first movable base 83aX and the sliding amount of the second movable base 83bX the same (the center between the antennas is aligned), and the other in which the distance between the antennas is enlarged / shortened by making the sliding amount of the first movable base 83aX and the sliding amount of the second movable base 83bX different (the center between the antennas is shifted), and these ways can be switched depending on the reception conditions.

[0057] <Third embodiment> The positioning unit 70Y shown in this embodiment differs from the positioning unit 70X shown in the second embodiment in part in the configuration for changing the positional relationship between the GNSS antennas 71 and 72. Specifically, the configuration differs from that of the positioning unit 70X in that it has a configuration for changing the arrangement direction of the GNSS antennas 71 and 72 in addition to a configuration for changing the distance between the antennas.

[0058] 7(b), a turntable 91Y is disposed on the upper surface of the upper rotating body 12 (machine room 36) so as to be rotatable about a central axis CL extending in the vertical direction. A fixed base 82X of the positioning unit 70 is fixed to the turntable 91Y, and the orientation of the positioning unit 70, i.e., the arrangement direction of the GNSS antennas 71 and 72, is changed by rotating the turntable 91Y.

[0059] The turntable 91Y is provided with a motor 92Y, which is an actuator for the turntable 91Y, and a rotary encoder (not shown) for detecting the rotational position of the turntable 91Y. The motor 92Y and the rotary encoder are connected to a controller 50 (see FIG. 3(a)). In this embodiment, the controller 50 includes an antenna distance change unit 54 and an orientation change unit (not shown) that can change the arrangement direction of the GNSS antennas 71 and 72 depending on the reception conditions, etc. For example, if the reception conditions are not appropriate even when the antenna distance is set to the maximum (tenth state LV10), the orientation change unit operates the motor 92Y to rotate the turntable 91Y and change the arrangement direction of the GNSS antennas 71 and 72. In other words, the controller 50 attempts to improve the reception conditions by changing the arrangement direction of the GNSS antennas 71 and 72.

[0060] Furthermore, with regard to the pile driver 10, the holding posture of the reader 15 may change depending on the situation, and the presence or absence of attachments may vary depending on the construction site and construction content. In other words, the function of changing the inter-antenna distance of the positioning unit 70 may be partially restricted depending on the operational status of the pile driver 10. For example, the positioning unit 70 may be restricted so that it cannot be switched to the tenth state LV10, etc., in order to avoid contact with surrounding components. In this regard, the configuration shown in this embodiment makes it possible to alleviate restrictions on changing the inter-antenna distance by changing the arrangement direction of the GNSS antennas 71, 72 depending on the operational status.

[0061] Incidentally, the configuration in which the turntable 91Y is rotated to change the alignment direction of the GNSS antennas 71, 72 is also preferable in terms of preventing the positioning unit 70Y from protruding outside the vehicle. For example, when the reader 15 (see FIG. 1) is lowered to move the pile driver 10 toward the target burial position, interference with the reader 15 can be prevented by maintaining the alignment direction of the GNSS antennas 71, 72 in the width direction of the pile driver 10 (upper rotating body 12). After the pile driver 10 reaches the target burial position and the reader 15 is erected, the alignment direction of the GNSS antennas 71, 72 is changed to the fore-and-aft direction of the upper rotating body 12. Because the upper rotating body 12 is long in the front-to-rear direction, changing the alignment direction of the GNSS antennas 71, 72 can prevent the positioning unit 70 from protruding outside the vehicle while increasing the distance between the antennas.

[0062] <Fourth embodiment> In the first embodiment, the radio wave reception status is determined based on three items: the reception status of the positioning unit 70 (receivers 73, 74), the number of reception satellites, and the HDOP value. However, in this embodiment, the items used to determine the reception status are different from those in the first embodiment. Below, the process for changing the antenna distance in this embodiment will be described, focusing on these differences.

[0063] In the antenna distance change process of this embodiment, when the antenna distance change operation is not in progress (S101: NO), the radio wave reception status of each of the first antenna 71 and the second antenna 72 is checked to determine whether the number of GNSS satellites 65 for which the reception status is in a predetermined state (in this embodiment, a "good" state) has reached a specified number (in this embodiment, "10"). Note that the reception status is classified into three categories: "good," "fair," and "poor." In this embodiment, the condition is met only when the reception status is "good," but this does not negate the possibility of the condition also being met when the reception status is "fair." Note that while it is assumed that "good," "fair," and "poor" are determined based on the strength of the received radio waves, they may also be determined based on the difference between the time recorded in the received radio waves and the time on the controller 50.

[0064] If the number of GNSS satellites 65 with a reception status of "good" for each antenna 71, 72 reaches a specified number, the reception status monitor 53 determines whether the HDOP value is equal to or less than a reference value (S104). If the number of GNSS satellites 65 with a reception status of "good" reaches a specified number and the HDOP value is equal to or less than the reference value, the reception status is deemed to be appropriate, and similarly to the first embodiment, the operation restriction release process (S105), the process of determining whether a shortened restriction is in effect (S106), the process of shortening the antenna distance (S107), and the process of setting the shortened restriction period (S108) are executed. On the other hand, if any of the conditions related to the reception status are not met, the operation restriction process (S109), the process of increasing the antenna distance (S110), and the process of setting the shortened restriction period (S108) are executed.

[0065] <Other embodiments> In the above embodiments, the antenna distance is automatically changed depending on the reception status of radio waves from the GNSS satellite 65, but the present invention is not limited to this. It is also possible to change the antenna distance based on a user's change operation (operation to specify the antenna distance).

[0066] In the above embodiments, the state in which the inter-antenna distance is smallest (first state LV1) is set as the basic state (default) of the positioning unit 70, and the state of the positioning unit 70 is switched so as to increase the inter-antenna distance when it is determined that the radio wave reception conditions are not appropriate, but this may be modified as follows: That is, the state in which the inter-antenna distance is largest (tenth state LV10) may be set as the basic state of the positioning unit 70, and the state of the positioning unit 70 may be switched so as to decrease the inter-antenna distance when it is determined that the radio wave reception conditions are appropriate.

[0067] In the above embodiments, the antenna distance is increased based on the number of satellites receiving radio waves reaching a predetermined number of "10" or more. However, the predetermined number may be changed arbitrarily. For example, it may be set to "4." Furthermore, the predetermined number may be changed depending on the antenna distance.

[0068] Instead of or in addition to HDOP, PDOP or VDOP can be set as a judgment item for reception conditions.

[0069] In the third embodiment, if changing the antenna distance does not improve the radio wave reception, the antenna distance change mechanism 81X is rotated to change the antenna arrangement direction. That is, the configuration prioritizes changing the antenna distance over changing the antenna arrangement direction. This can also be modified as follows. That is, a configuration can be adopted in which changing the antenna arrangement direction is prioritized over changing the antenna distance. It is also possible to change the order of priority between changing the antenna distance and changing the antenna arrangement direction depending on the antenna distance. For example, to prevent the positioning unit 70 from protruding from the upper rotating body 12, a configuration can be adopted in which changing the distance is prioritized in the first state LV1 to the sixth state LV6, and if the reception condition does not improve even in the sixth state LV6, the antenna arrangement direction is changed before changing to the seventh state LV7 to try to improve the reception condition.

[0070] In the third embodiment, a configuration was exemplified in which a distance-changing mechanism (determining unit 84X, motors 85aX, 85bX, etc.) for changing the distance between the antennas and a direction-changing mechanism (turntable 91Y, motor 92Y, etc.) were used together as the "drive mechanism," but it is also possible to omit the distance-changing mechanism.

[0071] In the above embodiments, the positioning unit 70 is applied to the pile driver 10, but a configuration equivalent to the positioning unit 70 may be applied to other construction machinery such as an excavator or a crawler crane, or may be applied to a transport vehicle such as a self-propelled carrier or an AGV. [Explanation of symbols]

[0072] 10...pile driver as industrial vehicle, 11...lower running body, 12...upper rotating body, 50...controller, 51...vehicle control unit, 52...positioning unit, 53...reception status monitoring unit as monitoring unit, 54...antenna distance changing unit as drive control unit, 65...GNSS satellite, 70...positioning unit, 71...first antenna as satellite positioning antenna, 72...second antenna as satellite positioning antenna, 81...antenna distance changing mechanism as drive mechanism, 82...fixed base constituting base unit, 83...movable base constituting base unit, 85...motor, 91Y...turntable constituting base unit, 92Y...motor.

Claims

1. An industrial vehicle equipped with multiple satellite positioning antennas capable of receiving radio waves from satellites, the industrial vehicle having a drive mechanism that varies the relative distance between the satellite positioning antennas and a drive control unit that controls the drive mechanism.

2. a monitoring unit for monitoring the reception status of radio waves from the satellite; 2. The industrial vehicle according to claim 1, wherein the drive control unit controls the drive mechanism to change the relative distance of the satellite positioning antenna based on the monitoring result by the monitoring unit.

3. 3. The industrial vehicle according to claim 2, wherein the drive control unit controls the drive mechanism to increase the relative distance when the monitoring result by the monitoring unit does not indicate that the radio wave reception conditions are appropriate.

4. 4. The industrial vehicle according to claim 2, wherein the drive control unit controls the drive mechanism to reduce the relative distance when the monitoring result by the monitoring unit indicates that the radio wave reception conditions are appropriate over a predetermined period of time.

5. 2. The industrial vehicle according to claim 1, wherein the drive mechanism has a base portion on which the satellite positioning antenna is mounted, and the arrangement direction of the satellite positioning antenna can be changed by rotating the base portion.

6. An industrial vehicle equipped with multiple satellite positioning antennas capable of receiving radio waves from satellites, the industrial vehicle having a drive mechanism that changes the positional relationship of the satellite positioning antennas, and a drive control unit that controls the drive mechanism.

7. the industrial vehicle includes a lower traveling body and an upper rotating body rotatably provided on an upper portion of the lower traveling body, 7. The industrial vehicle according to claim 1, wherein the satellite positioning antenna and the drive mechanism are disposed on the upper rotating body.

Images