The present invention relates to a work assist device of a work machine and a method of recognizing a construction surface at a work site, the work assist device and the method assisting in performing work using a work machine.
A work machine including a machine body and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body has been known for years. The work member is, for example, an attachment including an earth-removing blade or a bucket capable of performing excavation work or leveling work.
Patent Literature 1 discloses a target work surface setting device (work assist device) that allows a worker operating a work machine to easily recognize the position of a target work surface (construction surface) virtually set in the ground. The target work surface setting device includes a work machine side computer incorporated in the work machine and an office side computer placed in an office separated away from a work site. When the setting switch of the work machine side computer is turned on, 3D data unique to the work site, the 3D data including a plan view, a cross-sectional view, and the like, is transmitted from the office side computer to the work machine side computer through a transceiver. The work machine side computer computes position information on the target work surface, based on the received 3D data.
The work machine side computer computes also three-dimensional position information on the work machine at the work site, based on position information sent from a GPS antenna unit provided on the work machine and correction information sent from a GPS base station set in the work site. The work machine side computer then compares the computed position information on the target work surface with the three-dimensional position information on the work machine to determine whether the work machine is within a range in which the work member can reach the target work surface, and informs the worker of the result of the determination. Being informed of the result of the determination, the worker understands a relative positional relationship between the work member and the target work surface, and is therefore able to efficiently carry out the excavation work and the leveling work at the work site.
According to the technique described in Patent Literature 1, setting the construction surface (target work surface) requires that a communication mechanism enabling communication between the work machine side computer and the office side computer be provided and that the work machine side computer have a large-capacity storage unit for storing 3D data unique to the work site. This leads to a complicated configuration of the work assist device that assists the work machine in performing work and to an increase in the cost of the work machine, thus posing a problem that some constructors have difficulty in introducing such a work assist machine.
An object of the present invention is to provide a work assist device of a work machine and a method of recognizing a construction surface at a work site, the work assistance device and the method allowing a worker to easily recognize a construction surface without the need of receiving 3D data unique to a work site from an external device or storing the 3D data in advance.
A work assist device of a work machine according to one aspect of the present invention, the work assist device being devised in view of the above problem, is a work assist device of a work machine including: a machine body having a traveling unit capable of traveling on the ground; and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body and capable of excavating the ground. The work assist device is configured to assist in work of forming, by the work machine, a given construction surface on a work site. The work assist device includes: a body coordinates information acquiring unit that can acquire body coordinates information that is information on absolute coordinates of a body reference point at the work site, the body reference point being set on the machine main body in advance; a body orientation information acquiring unit that can acquires body orientation information that is information on an orientation of the machine body with respect to the body reference point; a work member position information acquiring unit that can acquire work member position information that is information on a relative position of the work member to the machine body; a specific part coordinates computing unit that can compute and output absolute coordinates of a specific part of the work member at the work site, based on the body coordinates information acquired by the body coordinates information acquiring unit, on the body orientation information acquired by the body orientation information acquiring unit, and on the work member position information acquired by the work member position information acquiring unit; a placement information receiving unit that can receive pieces of placement information that is information indicating that the specific part of the work member is placed at least at three ground reference points associated with the construction surface according to travel of the traveling unit; a storage unit that stores absolute coordinates of the specific part as absolute coordinates the at least three ground reference points at the work site, respectively, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to the placement information receiving unit's receiving the placement information at the at least three ground reference points; a distance information input unit that can receive input of at least three pieces of distance information that is information indicating a distance from each of the at least three ground reference points to the construction surface in a vertical direction; a construction surface computing unit that computes an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit, and a construction surface information output unit that outputs information on the equation for the construction surface computed by the construction surface computing unit.
A method of recognizing a construction surface at a work site according to another aspect of the present invention includes: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing a work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in a vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; and outputting information on the computed equation for the construction surface and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site.
A method of recognizing a construction surface at a work site according to still another aspect of the present invention includes: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing a work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in a vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; outputting information on the computed equation for the construction surface and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site; providing the work site with a reference member for checking including a straight part that is parallel to the construction surface and that is perpendicular to a direction of traveling of the traveling body of the work machine in a plan view; operating the work machine to align a lower end part of an earth-removing blade, the lower end part extending in a left-to-right direction, with the straight part of the reference member for checking; and comparing a distance from a left end of the lower end part of the earth-removing blade to the construction surface with a distance from a right end of the lower end part of the same to the construction surface to check whether the computed equation for the construction surface is within a given range.
An embodiment of the present invention will hereinafter be described with reference to the drawings.
In the embodiment, the hydraulic excavator 100, which is an example of a work machine, is provided with the construction surface setting device 1. The excavator 100 includes a machine body 10, an attachment 30, and a dozer unit 40. The machine body 10 includes a lower body 11 and an upper slewing body 20. On both left and right sides of the lower body 11, crawler units 12 (traveling units) capable of traveling on the ground are attached, respectively. The upper slewing body 20 has a slewing frame 21 supported on the lower body 11 in such a way as to be capable of turning around a pivot extending in the vertical direction, a cab 22 allowing a worker to sit therein, an engine room 23 disposed behind the cab 22, an engine 24, a first hydraulic pump 25, a second hydraulic pump 26, and a support 27.
The engine 24 is placed in the engine room 23. The first hydraulic pump 25 and the second hydraulic pump 26 are driven by the engine 24, and each deliver hydraulic oil to a hydraulic circuit (not illustrated) for driving the attachment 30 and the dozer unit 40. The support 27 is disposed at a location that is on the slewing frame 21 and that is at the right side of the cab 22 (the back of the paper surface in
The dozer unit 40 (work member) is disposed on a front part of the lower body 11. The dozer unit 40 is supported by the machine body 10 in such a way as to be capable of moving relative to the machine body 10, and can excavate the ground. The dozer unit 40 has an earth-removing blade 41 and a support frame 42 (earth-removing blade support) that supports the earth-removing blade 41. The excavator 100 further includes a lift cylinder 43, a pair of left and right angle cylinders 44, and a tilt cylinder 45. The support frame 42 is supported by the lower body 11 of the machine body 10 in such a way as to be capable of swinging about a lift rotating shaft F1 extending in the left-to-right direction. The lift cylinder 43 extends and contracts in response to supply and discharge of hydraulic oil from and to the second hydraulic pump 26, and this extension/contraction causes the support frame 42 to swing about the lift rotating shaft F1. As a result, the earth-removing blade 41 swings in a lift direction D1 shown in
As shown in
The operation unit 51 is disposed in the cab 22, and receives operation instructions given by a worker, the operation instructions including an instruction on traveling actions of the crawler unit 12, an instruction on slewing actions of the upper stewing body 20, and an instruction on driving of the attachment 30 and the dozer unit 40.
The input unit 52 (placement information receiving unit, distance information input unit) is disposed in the cab 22, and receives various pieces of information input by the worker. According to the embodiment, in particular, the input unit 52 can receive pieces of placement information in order, the placement information being information indicating that at least according to traveling of the crawler unit 12, a specific part of the earth-removing blade 41 is placed at least at three ground reference points associated with the construction surface TS of the work site, the three ground reference points being located above the construction surface TS so that the specific part of the earth-removing blade 41 can be placed in order at the three ground reference points on the ground. The input unit 52 can also receive input of at least three pieces of distance information that is information indicating a distance from each of the at least three ground reference points to the construction surface TS in the vertical direction.
The body coordinates detection unit 53 (body coordinates information acquiring unit) can acquire body coordinates information that is information on absolute coordinates of a body reference point at the work site, the body reference point being set on the machine body 10 in advance. The body coordinates detection unit 53 includes a global navigation satellite system (GNSS) reference station 61 and a GNSS mobile station 62. The body reference point is set on the top surface of the cab 22. The GNSS reference station 61 is a reference station disposed at the work site or at a location closest to the work site. As shown in
The body angle detection unit 54 (body orientation information acquiring unit) can acquire body orientation information that is information on an orientation of the machine body 10 with respect to the body reference point. In the embodiment, the body angle detection unit 54 is an angle sensor (body angle sensor) disposed on the top surface portion of the cab 22 in correspondence to the body reference point. The body angle detection unit 54 detects respective rotations around x1, y1, and z1 axes with respect to a mobile station origin G1, as indicated in
The earth-removing blade angle detection unit 55 (work member position information acquiring unit) can acquire work member position information that is information on a relative position of the dozer unit 40 (earth-removing blade 41) to the machine body 10. In the embodiment, the earth-removing blade angle detection unit 55 is an angle sensor (earth-removing bladed angle sensor) disposed on the earth-removing blade 41. The earth-removing blade angle detection unit 55 detects respective rotations around x3, y3, and z3 axes with respect to an earth-removing blade origin G3, as indicated in
The drive unit 56 includes the engine 24, the first hydraulic pump 25, and the second hydraulic pump 26 that are described above, and further includes a drive/transmission mechanism, such as a hydraulic circuit and gears. The drive unit 56 receives a control signal from a drive control unit 501 of the controller 50, and drives the crawler unit 12, the slewing frame 21, the attachment 30, and the dozer unit 40.
The display unit 57 is disposed in the cab 22, and displays various pieces of information on actions of the excavator 100. In particular, the display unit 57 can display position information on the construction surface TS (information on the construction surface TS) based on an equation for the construction surface TS output from the output unit 506, which will be described later. The display unit 57 can also display information on a relative position between the construction surface TS and the specific part, based on absolute coordinates of the specific part output from the earth-removing blade coordinates computing unit 502.
The informing unit 58 is disposed in the cab 22 or outside the excavator 100, and informs the worker of various pieces of information. As an example, the informing unit 58 includes a speaker, a buzzer, a light, and the like.
The controller 50 includes a central processing unit (CPU), a read-only memory (ROM) storing a control program, a random access memory (RAM) used as a work area for the CPU, and the like. The controller 50 is connected to the operation unit 51, the input unit 52, the body coordinates detection unit 53, the body angle detection unit 54, the earth-removing blade angle detection unit 55, the drive unit 56, the display unit 57, the informing unit 58, and the like. As a result of the CPU's executing the control program stored in the ROM, the controller 50 functions as the controller including the drive control unit 501, the earth-removing blade coordinates computing unit 502, a construction surface computing unit 503, a determining unit 504, a storage unit 505, and an output unit 506.
In accordance with an instruction signal input to the operation unit 51, the drive control unit 501 controls the drive unit 56 to cause it to drive the crawler unit 12, the stewing frame 21, the attachment 30, and the dozer unit 40.
The earth-removing blade coordinates computing unit 502 (specific part coordinates computing unit) computes absolute coordinates of a specific part of the earth-removing blade 41 at the work site. Specifically, the earth-removing blade coordinates computing unit 502 can compute and output absolute coordinates of a specific part of the earth-removing blade 41 at the work site, based on the body coordinates information acquired by the body coordinates detection unit 53, the body orientation information acquired by the body angle detection unit 54, and the work member position information acquired by the earth-removing blade angle detection unit 55.
The construction surface computing unit 503 computes an equation for the construction surface TS in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit 505, and the at least three pieces of distance information input to the input unit 52. More specifically, the construction surface computing unit 503 computes absolute coordinates of at least three virtual reference points located respectively below the at least three ground reference points, from the absolute coordinates of the at least three ground reference points and the at least three pieces of distance information, and computes the equation of the construction surface TS, based on the computed absolute coordinates of at least three virtual reference points. A method of computing the construction surface TS will be described in detail later.
The determining unit 504 executes various determination operations in a flow of a construction surface TS setting process. The determining unit 504 executes also a given determination process when checking the equation for the construction surface TS computed and determined by the construction surface computing unit 503.
The storage unit 505 stores various pieces of information that is referred to in the flow of the construction surface TS setting process. The storage unit 505 stores also various pieces of threshold information and the like in advance. Further, the storage unit 505 stores absolute coordinates of the specific part as absolute coordinates of the at least three ground reference points at the work site, the absolute coordinates of the specific part being computed by the earth-removing blade coordinates computing unit 502 in correspondence to the input unit 52 receiving the placement information at the at least three ground reference points.
The output unit 506 (construction surface information output unit) outputs information on the equation for the construction surface TS computed and determined by the construction surface computing unit 503.
As shown in
On the top surfaces of the horizontal plates, a first reference point P1, a second reference point P2, and a third reference point P3 (which are all ground reference points) are set in advance, respectively, the first, second, and third reference points P1, P2, and P3 corresponding to the construction surface TS scheduled to be formed by excavation and ground leveling work. A first depth L1, a second depth L2, and a third depth L3 (each serving as distance information), which represent a distance from the first reference point P1 to the construction surface TS, a distance from the second reference point P2 to the same, and a distance from the third reference point P3 to the same in the vertical direction, respectively, are given in advance as known values at the work site. These distances are noted, for example, on side surfaces of the first horizontal plate K1, the second horizontal plate K2, and the third horizontal plate K3, respectively. Points reached by going down from the first reference point P1, the second reference point P2, and the third reference point P3 by the first depth L1, the second depth L2, and the third horizontal plate K3, respectively, are defined as a first virtual point Q1, a second virtual point Q2, and a third virtual point Q3 (which are all virtual reference points), respectively. It is a prerequisite that the first reference point P1, the second reference point P2, and the third reference point P3 be not on a straight line.
As shown in
The construction surface computation step in step S01 of
When the earth-removing blade coordinates computing unit 502 becomes able to compute the absolute coordinates of the earth-removing blade left end 41L of the earth-removing blade 41, a reference information receiving step is started (step S12 of
Subsequently, an instruction request for setting the first reference point P1 (n=1) is displayed on the display unit 57. Responding to the instruction request, the worker operates the crawler unit 12 and the dozer unit 40 of the excavator 100 to place the earth-removing blade left end 41L of the earth-removing blade 41 at the first reference point P1 of
Specifically, an instruction request for setting the second reference point P2 (n=2) is displayed on the display unit 57. Responding to the instruction request, the worker operates the crawler unit 12 and the dozer unit 40 of the excavator 100 to place the earth-removing blade left end 41L of the earth-removing blade 41 at the second reference point P2 of
Eventually, n=N holds in step S26 in a case of n=3 (YES in step S26), from which the process flow proceeds to step S13 of
In step S13 of
In step S14, the construction surface computing unit 503 computes absolute coordinates of the first virtual point Q1, the second virtual point Q2, and the third virtual point Q3 (three specific virtual reference points) that are located respectively below the three specific ground reference points, from the absolute coordinates of the first reference point P1, the second reference point P2, and the third reference point P3 (three specific ground reference points) and the first depth L1, the second depth L2, and the third depth L3 (three pieces of specific distance information). At this time, the depth indicated by the depth information corresponding to the absolute coordinates of each reference point is subtracted from the Z coordinate of each reference point to compute the absolute coordinates of the virtual point corresponding to the reference point. The construction surface computing unit 503 then computes an equation for a plane passing through the computed three specific virtual reference points, as an equation for the construction surface TS.
A process by which the construction surface computing unit 503 computes the equation for the construction surface TS in step S14 of
As shown in
When the construction surface computing unit 503 computes and determines the equation for the construction surface TS in step S14 of
Next, a correction computation process executed in step S04 of
Through the same flow of steps as shown in
When it is determined that the equation for the construction surface TS is within the given allowable range, correcting the equation for the construction surface TS is unnecessary, in which case the process flow proceeds from step S04 to step S05 of
One example of a method of calculating the mean square plane is the following method. The equation for the construction surface TS is computed in such a way as to minimize the sum of squares of respective distances from the four virtual points to the construction surface TS. When it is assumed, as described above, that the coefficients of X, Y, and Z in the equation expressing the construction surface TS are A, B, and C, respectively, parameter values for A, B, and C are computed in such way as to minimize the sum of squares of respective distances from the four virtual points. When the sum of squares of respective distances Li from the four virtual points is defined as F, F is expressed as F=Σ(Li)2. Partially differentiating both sides of F=Σ(Li)2 yields three-dimensional simultaneous equations, from which A, B, and C can be determined. To obtain each of A, B, and C as a unit vector, a precondition A2+B2+C2=1 needs to be met. As solutions to the above equations, the LU decomposition using known matrices, the Lagrange undetermined constant method, or the like may be adopted.
It should be noted that the above method of determining the equation for the construction surface TS based on the four virtual points is not limited to the correction computation step hut may be adopted at the construction surface computation step in step S01. Specifically, step S01 is not limited to the step of computing and determining the construction surface TS based on the three ground reference points and distance information but may be a step of computing and determining the construction surface TS based on four or more ground reference points and distance information. In this case, by increasing the number of reference points, a delicate setting error that is made at the time of blade edge setting can be canceled.
In the embodiment, after the construction surface TS is computed and determined, the worker is able to check a positional relationship between the construction surface TS and the earth-removing blade 41 before excavating the ground with the earth-removing blade 41 of the excavator 100.
As an example, a finishing stake for checking is placed on the rear side (this side) in the direction of traveling of the excavator 100 at the work site, as shown in
In the embodiment, as shown in
In a state where the construction surface IS is computed and determined in advance based on the above flow of steps, the worker operates the excavator 100 to match the lower end part 41S of the earth-removing blade 41 to the construction surface virtual string FL on this side in the traveling direction DS, as shown in
According to the embodiment, when the worker starts operating the excavator 100 from the state shown in
As described above, according to the embodiment, the earth-removing blade coordinates computing unit 502 can compute and output the absolute coordinates of the earth-removing blade left end 41L (specific part) of the earth-removing blade 41 at the work site, based on the coordinates information (body coordinates information) on the machine body 10 acquired by the body coordinates detection unit 53, on the orientation information (body orientation information) of the machine body 10 acquired by the body angle detection unit 54, and on the position information (work member position information) on the earth-removing blade 41 acquired by the earth-removing blade angle detection unit 55. When the earth-removing blade left end 41L is placed at each ground reference point in order and the input unit 52 receives placement information on the earth-removing blade left end 41L, the storage unit 505 can store the absolute coordinates of the earth-removing blade left end 41L, the absolute coordinates being computed by the earth-removing blade coordinates computing unit 502, as the absolute coordinates of each ground reference point. The input unit 52 (distance information input unit) receives depth information (distance information) on each ground reference point, the depth information indicating the distance from each ground reference point to the construction surface TS. As a result, the construction surface computing unit 503 can compute an equation for the construction surface TS in an absolute coordinate system of the work site, from the absolute coordinates of each ground reference point and the distance information corresponding to the absolute coordinates. The worker thus sets each ground reference point, using finishing stakes, leveling strings, and the like usually provided in the work site, places the earth-removing blade left end 41L of the excavator 100 at each ground reference point in order, and inputs the distance information on the distance from each ground reference point to the construction surface TS, to the input unit 52. By merely carrying out these operations, the worker is able to easily obtain the equation for the construction surface TS at the work site and to easily recognize the position of the construction surface TS, based on the information output by the output unit 506. In addition, receiving information including cumulous data, such as 3D data of the work site, from external equipment or storing the above-mentioned information in the storage unit 505 in advance is unnecessary, which prevents complication in configuration of the construction surface setting device 1 and suppresses an increase in the cost of the construction surface setting device 1.
In the embodiment, the construction surface computing unit 503 computes absolute coordinates of the virtual reference points located respectively below the ground reference points, from the absolute coordinates of the ground reference points and the distance information, and computes the equation for the construction surface TS, based on the computed absolute coordinates of the virtual reference points. According to such a configuration, based on the absolute coordinates of the virtual reference points set virtually in the ground, the construction surface computing unit 503 can easily compute the equation for the construction surface TS according to a plane equation computing method.
In the embodiment, the construction surface computing unit 503 computes the absolute coordinates of three virtual reference points (specific virtual reference points) located respectively below three ground reference points (specific ground reference points), and computes an equation for a plane passing through the computed three virtual reference points, as the equation for the construction surface TS. Based on the three virtual reference points, therefore, the equation for the construction surface TS can be computed easily in a short time.
However, as described above, the construction surface computing unit 503 may compute the absolute coordinates of four virtual reference points (specific virtual reference points) and compute an equation for a least square plane based on the computed four virtual reference points, as the equation for the construction surface TS. According to such a configuration, the equation for the construction surface TS can be computed with higher accuracy, based on the four virtual reference points. It should be noted that the position information (plane equation) of the construction surface TS may be computed and determined based on five or more ground reference points (virtual reference points).
In the embodiment, the construction surface computing unit can compute absolute coordinates of at least one virtual reference point for checking located below at least one ground reference point for checking, from absolute coordinates of the at least one ground reference point for checking and at least one piece of distance information for checking. The determining unit 504 determines whether the equation for the construction surface TS is within the given allowable range, based on the computed absolute coordinates of the virtual reference point for checking and on the equation for the construction surface TS, the equation being computed by the construction surface computing unit 503. According to such a configuration, the worker places the earth-removing blade left end 41L of the excavator 100 at the ground reference point for checking and inputs the distance information for checking to the input unit 52. The worker's merely carrying out these operations allows the determining unit 504 to determine the accuracy of the equation for the construction surface IS, based on the equation for the construction surface IS having been computed and on the absolute coordinates of the virtual reference point for checking. This, therefore, prevents a case where an error in excavation and ground leveling work occurs at the work site because of the erroneously computed equation for the construction surface TS. In addition, the worker is able to start the work after sufficiently confirming the accuracy of the computed equation for the construction surface.
In the embodiment, the body angle detection unit 54 includes a body angle sensor that detects and outputs a lift angle, a pitch angle, and a yaw angle of the machine body 10 with respect to the body reference point on the cab 22, as orientation information on the machine body 10. The body coordinates detection unit 53 acquires coordinate information on the machine body 10, using the global positioning satellite system. According to such a configuration, even in an environment in which a shielding object is present around the excavator 100, position information and the orientation information on the machine body 10 can be detected.
In the embodiment, information displayed on the display unit 57 allows the worker to easily recognize the position of the construction surface TS and to accurately perform work while recognizing the relative positional relationship between the construction surface TS and the earth-removing blade 41 from the information displayed on the display unit.
In the embodiment, the earth-removing blade 41 of the dozer unit 40 of the excavator 100 is used as a reference for computing the absolute coordinates of each ground reference point. According to such a configuration, the worker can easily recognize the equation and position information of the construction surface TS by operating the excavator 100 to place the earth-removing blade 41 at each ground reference point. In particular, when the earth-removing blade 41 of the dozer unit 40 located in advance at a position lower than the attachment 30 is used, the ground reference point (finishing stake, etc.) set at the work site can also be located at a lower position, in which case the height of a member provided to set the ground reference point can be kept low.
In the embodiment, the earth-removing blade angle detection unit 55 includes the earth-removing blade angle sensor capable of detecting and outputting a lift angle about the lift rotating shaft F1 of the earth-removing blade 41, as position information (work member position information) on the earth-removing blade 41. According to such a configuration, by adjusting the lift angle of the earth-removing blade 41 in addition to adjusting traveling of the crawler unit 12, the worker can easily place the earth-removing blade 41 of the excavator 100 at each ground reference point.
In the embodiment, the above earth-removing blade angle sensor can detect and output also a tilt angle about the tilt rotating shaft F3 of the earth-removing blade 41, as the position information on the earth-removing blade 41. According to such a configuration, because the earth-removing blade angle sensor can detect the tilt angle of the earth-removing blade 41, the worker can easily place the earth-removing blade 41 of the excavator 100 at the ground reference point by adjusting the lift angle of the earth-removing blade 41, in addition to adjusting the traveling of the crawler unit 12 and the lift angle as well. The earth-removing blade angle sensor can detect and output also an angular angle about the angular rotating shaft F2 of the earth-removing blade 41. This allows the worker to tilt the earth-removing blade 41 against the horizontal direction. It is therefore possible that, as shown in
In the embodiment, through the above flow of steps, the worker is able to recognize the position of the construction surface TS at the work site. A method of recognizing a construction surface at a work site according to the embodiment is a method of recognizing a construction surface at a work site, the method including: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing the above work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in the vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; and outputting information on the equation for the construction surface computed by the construction surface computing unit, and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site.
According to this method, the worker sets each ground reference point, using finishing stakes, leveling strings, and the like usually provided in the work site, places the specific part of the work machine at each ground reference point in order, and inputs the distance information on the distance from each ground reference point to the construction surface, to the input unit, and by merely carrying out these operations, the worker is able to easily obtain the equation for the construction surface at the work site and to easily recognize the position of the construction surface, based on the information output by the construction surface information output unit. In addition, receiving information including enormous data, such as 3D data of the work site, from external equipment or storing the above-mentioned information in the storage unit in advance is unnecessary, which prevents complication in configuration of the work assist device and suppresses an increase in the cost of the work assist device.
A method of recognizing a construction surface at a work site according to the embodiment is a method of recognizing a construction surface at a work site, the method including: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing the above work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in the vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; outputting information on the equation for the construction surface computed by the construction surface computing unit and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site; providing the work site with a reference member for checking including a straight part that is parallel to the construction surface and that is perpendicular to a direction of traveling of the traveling body of the work machine in a plan view; operating the work machine to align a lower end part of an earth-removing blade, the lower end part extending in a left-to-right direction, with the straight part of the reference member for checking; and comparing a distance from a left end of the lower end part of the earth-removing blade to the construction surface with a distance from a right end of the lower end part of the same to the construction surface to check whether the computed equation for the construction surface is within a given range.
According to this method, when the worker aligns the earth-removing blade with the reference member for checking and finds that respective distances from the left and right ends of the earth-removing blade to the construction surface are equal to each other with a margin of error within a given error range, the earth-removing blade and the construction surface are parallel to each other. The worker thus causes the earth-removing blade to dig into the ground without making any adjustment, and is able to perform excavation work on the construction surface in stable manner.
The construction surface setting device 1 according to the present invention, the excavator 100 including the construction surface setting device 1, and the method of recognizing the construction surface at the work site have been described above. The present invention is not limited to these device, excavator, and method, and may be implemented as the following modifications.
(1) According to the above embodiment, the earth-removing blade left end 41L of the earth-removing blade 41 is defined as the specific part. The specific part, however, may be the earth-removing blade right end 41R or a central part of the earth-removing blade 41. In addition, the absolute coordinates of each reference point may be computed based not on the earth-removing blade 41 but on a specific part of the attachment 30 (e.g., a part of the bucket at the front end of the attachment 30).
(2) Instead of specifying the ground reference position by the specific part of the machine body 10, the worker may input coordinates of the ground reference position directly to the input unit 52 in a state where the GNSS mobile station 62 is disposed at a position that should be stored. In this case, the worker presses a storage instruction switch (not illustrated) disposed in the cab 22 to send coordinates of the position of the GNSS mobile station 62 to the controller 50.
(3) A place where the ground reference point is set may be any place whose height from the construction surface TS (virtual reference point) is known at the work site, such as the top of the vertical plate of the finishing stake, the top surface or bottom surface of the horizontal plate, a reference line drawn on the horizontal plate, and the leveling string stretched between the finishing stakes. By matching the specific part of the earth-removing blade 41 to the ground reference point set in such a place, the worker is able to carry out more understandable positioning of the earth-removing blade 41. It is desirable, in particular, that the ground reference point be set at a position that the worker in the cab 22 can visually recognize easily.
(4) The locations of the ground reference points are not limited to the periphery of a space above the construction surface TS, and may be outside the construction area. Using finishing stakes placed outside the construction area as the reference points allows computing and determining the construction surface TS using only the same finishing stakes as conventional finishing stakes, in which case enormous 3D shape data indicating the topography of the work site or the like is no longer necessary.
(5) In the above embodiment, the body coordinates detection unit 53 includes the GNSS reference station 61 and the GNSS mobile station 62. The body coordinates detection unit 53, however, may acquire body coordinates information that is information on absolute coordinates of the body reference point at the work site, the body reference point being set in advance on the machine body 10, using a total station. As an example, a master unit equipped with a camera capable of measuring a distance and an angle is installed at a work site in place of the GNSS reference station 61, and a slave unit including a prism of which an image is captured by the camera is attached to the excavator 100 in place of the GNSS mobile station 62. According to such a configuration, the body coordinates information can be detected accurately, and can be detected even at a work site with its above space blocked, such as a work site in a tunnel.
(6) In the above embodiment, as shown in
A work assist device of a work machine according to one aspect of the present invention, the work assist device being devised in view of the above problem, is a work assist device of a work machine including: a machine body having a traveling unit capable of traveling on the ground; and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground. The work assist device is configured to assist in work of forming, by the work machine, a given construction surface on a work site. The work assist device includes: a body coordinates information acquiring unit that can acquire body coordinates information that is information on absolute coordinates of a body reference point at the work site, the body reference point being set on the machine main body in advance; a body orientation information acquiring unit that can acquires body orientation information that is information on an orientation of the machine body with respect to the body reference point; a work member position information acquiring unit that can acquire work member position information that is information on a relative position of the work member to the machine body; a specific part coordinates computing unit that can compute and output absolute coordinates of a specific part of the work member at the work site, based on the body coordinates information acquired by the body coordinates information acquiring unit, on the body orientation information acquired by the body orientation position information acquiring unit, and on the work member position information acquired by the work member position information acquiring unit; a placement information receiving unit that can receive pieces of placement information that is information indicating that the specific part of the work member is placed at least at three ground reference points associated with the construction surface; a storage unit that stores absolute coordinates of the specific part as absolute coordinates of the at least three ground reference points at the work site, respectively, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to the placement information receiving unit's receiving the placement information at the at least three ground reference points; a distance information input unit that can receive input of at least three pieces of distance information that is information indicating a distance from each of the at least three ground reference points to the construction surface in a vertical direction; a construction surface computing unit that computes an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit, and a construction surface information output unit that outputs information on the equation for the construction surface computed by the construction surface computing unit.
According to this configuration, the construction surface computing unit can compute the equation for the construction surface in the absolute coordinate system of the work site, from the absolute coordinates of each ground reference point and the distance information corresponding to the absolute coordinates. The worker thus sets each ground reference point, places the specific part at each ground reference point in order, and inputs the distance information on the distance from each ground reference point to the construction surface, to the input unit. By merely carrying out these operations, the worker is able to easily obtain the equation for the construction surface at the work site and to easily recognize the position of the construction surface, based on the information output by the construction surface information output unit. In addition, receiving information including enormous data, such as 3D data of the work site, from external equipment or storing the above-mentioned information in the storage unit in advance is unnecessary, which prevents complication in configuration of the work assist device and suppresses an increase in the cost of the work assist device. The worker may set the ground reference points using finishing stakes, leveling strings, and the like conventionally used at the work site.
In the above configuration, it is desirable that the construction surface computing unit compute absolute coordinates of at least three virtual reference points located respectively below the at least three ground reference points, from the absolute coordinates of the at least three ground reference points and the at least three pieces of distance information and compute the equation for the construction surface, based on the computed absolute coordinates of the at least three virtual reference points.
According to this configuration, based on the absolute coordinates of three or more virtual reference points set virtually in the ground, the construction surface computing unit can easily compute the equation for the construction surface according to a plane equation computing method.
In the above configuration, it is preferable that the at least three ground reference points include three specific ground reference points, that the distance information input unit receive input of three pieces of specific distance information indicating a distance from each of the three specific ground reference points to the construction surface in the vertical direction, and that the construction surface computing unit compute absolute coordinates of three specific virtual reference points located respectively below the three specific ground reference points, from the absolute coordinates of the three specific ground reference points and the three pieces of specific distance information and compute an equation for a plane passing through the computed three specific virtual reference points, as the equation for the construction surface.
According to this configuration, the equation for the construction surface can be computed easily in a short time, based on the three specific virtual reference points.
In the above configuration, the at least three ground reference points may include at least four specific ground reference points, that the distance information input unit receive input of at least four pieces of specific distance information indicating a distance from each of the at least four specific ground reference points to the construction surface in the vertical direction, and that the construction surface computing unit compute absolute coordinates of at least four specific virtual reference points located respectively below the at least four specific ground reference points, from the absolute coordinates of the at least four specific ground reference points and the at least four pieces of specific distance information and compute an equation for a least-square plane based on the computed at least four specific virtual reference points, as the equation for the construction surface.
According to this configuration, the equation for the construction surface can be computed with higher accuracy, based on the four or more specific virtual reference points.
In the above configuration, it is desirable that the placement information receiving unit be able to further receive placement information for checking indicating that the specific part is placed on the at least one ground reference point for checking associated with the construction surface according to traveling of the traveling unit, that the storage unit be able to store absolute coordinates of the specific part as absolute coordinates of the at least one ground reference point for checking at the work site, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit, in correspondence to the placement information receiving unit's receiving the placement information for checking, that the distance information input unit be able to receive input of at least one piece of distance information for checking that is information indicating a distance from the at least one ground reference point for checking to the construction surface in the vertical direction, that the construction surface computing unit be able to compute absolute coordinates of at least one virtual reference point for checking located below the at least one ground reference point for checking, from the absolute coordinates of the at least one ground reference point for checking and the at least one piece of distance information for checking, and that the work assist device further includes a determining unit that determines whether the equation for the construction surface is within a given allowable range, based on the computed absolute coordinates of the virtual reference point for checking and on the equation for the construction surface computed in advance by the construction surface computing unit.
According to this configuration, the worker places the specific part of the work machine at the ground reference point for checking and inputs the distance information for checking to the distance information input unit, and the worker's merely carrying out these operations allows the determining unit to determine the accuracy of the equation for the construction surface, based on the equation for the construction surface having been computed and on the absolute coordinates of the virtual reference point for checking. This allows the worker to start the work after sufficiently confirming the accuracy of the computed equation for the construction surface.
In the above configuration, it is desirable that the body orientation information acquiring unit includes a body angle sensor that detects and outputs a lift angle, a pitch angle, and a yaw angle of the machine body with respect to the body reference point, as the body orientation information. It is also desirable that the body coordinates information acquiring unit acquire the body coordinates information, using the global positioning satellite system or the total station.
In the above configuration, it is desirable that the work assist device further includes a display unit capable of displaying information on the equation for the construction surface, the information being output from the construction surface information output unit.
According to this configuration, the worker can easily recognize the position of the construction surface by the information displayed on the display unit.
In the above configuration, it is desirable that the display unit be able to display also information on a relative position between the construction surface and the specific part, based on the absolute coordinates of the specific part output from the specific part coordinates computing unit.
According to this configuration, the worker is able to accurately perform the work while recognizing a relative positional relationship between the construction surface and a wok member by referring to the information displayed on the display unit.
In the above configuration, it is preferable that the work member of the work machine includes an earth-removing blade and an earth-removing blade support supporting the earth-removing blade, the earth-removing blade support being supported by the machine body in such a way as to be capable of swinging about a lift rotating shaft extending in the left-to-right direction, and that the specific part coordinates computing unit be able to compute and output absolute coordinates of a specific part of the earth-removing blade, as a specific part of the work member at the work site.
According to this configuration, the worker can easily recognize the position of the construction surface by operating the work machine to place the earth-removing blade at each ground reference point.
In the above configuration, it is desirable that the work member position information acquiring unit includes an earth-removing blade angle sensor capable of detecting and outputting a lift angle about the lift rotating shaft of the earth-removing blade, as the work member position information.
According to this configuration, because the work member position information acquiring unit includes the earth-removing blade angle sensor, the worker can easily place the earth-removing blade of the work machine at the ground reference point by adjusting the lift angle of the earth-removing blade, in addition to adjusting traveling of the traveling unit.
In the above configuration, it is preferable that the earth-removing blade of the work member be supported by the earth-removing blade support in such a way as to be capable of swinging about a tilt rotating shaft extending in the left-to-right direction, and that the earth-removing blade angle sensor be able to detect and output also a tilt angle about the tilt rotating shaft of the earth-removing blade, as the work member position information.
According to this configuration, because the earth-removing blade angle sensor can detect the tilt angle of the earth-removing blade, the worker can easily place the earth-removing blade of the work machine at the ground reference point by adjusting the lift angle of the earth-removing blade, in addition to adjusting traveling of the traveling unit and the lift angle as well.
A method of recognizing a construction surface at a work site according to another aspect of the present invention is a method of recognizing a construction surface at a work site, the method including: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing the work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in the vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; and outputting information on the computed equation for the construction surface and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site.
According to this method, the worker sets each ground reference point, places the specific part of the work machine at each ground reference point in order, and inputs the distance information on the distance from each ground reference point to the construction surface, to the input unit, and by merely carrying out these operations, the worker is able to easily obtain the equation for the construction surface at the work site and to easily recognize the position of the construction surface, based on the information output by the construction surface information output unit. In addition, receiving information including enormous data, such as 3D data of the work site, from external equipment or storing the above-mentioned information in the storage unit in advance is unnecessary, which prevents complication in configuration of the work assist device and suppresses an increase in the cost of the work assist device.
A method of recognizing a construction surface at a work site according to still another aspect of the present invention is a method of recognizing a construction surface at a work site, the method including: preparing a work machine including a machine body having a traveling unit capable of traveling on the ground and a work member supported by the machine body in such a way as to be capable of moving relative to the machine body, the work member being capable of excavating the ground, and preparing the above work assist device of the work machine as well; placing the specific part of the work member in order at the at least three ground reference points associated with the construction surface, according to at least traveling of the traveling unit and storing absolute coordinates of the specific part in the storage unit as absolute coordinates of each of the ground reference points, the absolute coordinates of the specific part being computed by the specific part coordinates computing unit in correspondence to each of the ground reference points; inputting at least three pieces of distance information to the distance information input unit, the distance information indicating a distance from each of the at least three ground reference points to the construction surface in the vertical direction; computing an equation for the construction surface in an absolute coordinate system of the work site, from the absolute coordinates of the at least three ground reference points, the absolute coordinates being stored in the storage unit, and the at least three pieces of distance information input to the distance information input unit; outputting information on the equation for the construction surface computed by the construction surface computing unit and, based on the output information, allowing a worker to recognize a position of the construction surface at the work site; providing the work site with a reference member for checking including a straight part that is parallel to the construction surface and that is perpendicular to a direction of traveling of the traveling body of the work machine in a plan view; operating the work machine to align a lower end part of the earth-removing blade, the lower end part extending in the left-to-right direction, with the straight part of the reference member for checking; and comparing a distance from a left end of the lower end part of the earth-removing blade to the construction surface with a distance from a right end of the lower end part of the same to the construction surface to check whether the computed equation for the construction surface is within a given range.
According to this method, by merely aligning the earth-removing blade with the reference member for checking, the worker is able to check the accuracy of the equation for the construction surface, from a relative positional relationship between the earth-removing blade and the construction surface. When the worker finds that respective distances from the left and right ends of the earth-removing blade to the construction surface are equal to each other with a margin of error within a given error range, the worker causes the earth-removing blade to dig into the ground without making any adjustment, and is able to perform excavation work on the construction surface in stable manner.
The present invention provides a work assist device of a work machine and a method of recognizing a construction surface at a work site, the work assistance device and the method allowing a worker to easily recognize a construction surface without the need of receiving 3D data unique to a work site from an external device or storing the 3D data in advance.
Number | Date | Country | Kind |
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2019-228329 | Dec 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/039417 | 10/20/2020 | WO |