hydraulic excavator

Abstract

To check on a monitor the areas where a current topography has not been measured.SOLUTION: The present invention comprises a vehicle body with driver's cab, a front work machine attached to the vehicle body, a monitor installed in the driver's cab, a distance meter that measures multiple distance measurement points on a current topography around the vehicle body, and a controller that causes the monitor to display measurement data of the current topography based on the output of the distance meter. The controller calculates horizontal coordinates of the plurality of measurement points based on the output of the distance meter, calculates a horizontal distance between each measurement point of the plurality of measurement points and an adjacent measurement point, causes the monitor to display height data calculated based on the output of the distance meter on the monitor as measurement data of the current topography for areas of distance measurement points whose horizontal spacing with adjacent measurement points is equal to or less than a set interval, and causes the monitor to display a message indicating that an area of a positioning point whose horizontal interval with an adjacent measurement point is larger than the set interval is an unmeasurable area in which measurement is not possible.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a hydraulic excavator. [Background technology]

[0002] When developing land with a hydraulic excavator, skill is required to operate the front working equipment to efficiently and accurately form the designed terrain (target terrain). Therefore, hydraulic excavators are sometimes equipped with a so-called machine guidance (MG) function that guides the operation so that even operators with little experience in operating hydraulic excavators can work accurately and efficiently. One type of MG uses a range finder such as a laser scanner to scan the ground surface of the current terrain (present terrain) being developed by the front working equipment, and displays the measurement data of the present terrain on a monitor along with the designed terrain data (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 175917 Summary of the Invention [Problem to be solved by the invention]

[0004] The current topography during construction is not necessarily monotonous, and may be transiently undulating. In this case, the laser beam emitted from the rangefinder may be blocked by the ground surface in front, resulting in areas that are not illuminated. When an obstacle blocking the laser beam exists, it may be difficult to determine whether the measurement data displayed on the monitor truly represents the current topography. In such a situation, the operator must visually compare the measurement data displayed on the monitor with the current topography during construction to grasp the true current topography while working, which results in reduced work efficiency.

[0005] An object of the present invention is to provide a hydraulic excavator that can improve work efficiency by enabling areas where the current topography has not been measured to be checked on a monitor. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a vehicle body having a driver's cab, a front working implement attached to the vehicle body, a monitor provided in the driver's cab, a rangefinder for measuring distances to a plurality of distance measurement points on the current topography around the vehicle body, Dividing the periphery of the vehicle body into a plurality of meshes; Measurement data of the current terrain based on the output of the range finder For each mesh and a controller for displaying the horizontal coordinates of the plurality of distance measurement points based on the output of the rangefinder, and for each of the plurality of distance measurement points, calculating a horizontal interval between adjacent distance measurement points, and determining whether the horizontal interval between adjacent distance measurement points is Set based on the mesh size For areas with distance measurement points less than the set interval, the height data calculated based on the output of the rangefinder is used as the measurement data of the current topography. For each mesh The area of ​​the positioning point where the horizontal interval between adjacent ranging points is greater than the set interval is displayed on the monitor. The mesh in which the distance measurement point does not exist is Unmeasurable area where measurement is not possible as The monitor displays Shown We provide a hydraulic excavator that can [Effects of the Invention]

[0007] According to the present invention, areas where the current topography has not been measured can be checked on the monitor, thereby improving work efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing the overall structure of a hydraulic excavator according to a first embodiment of the present invention. [Figure 2] Functional block diagram of a controller provided in a hydraulic excavator according to a first embodiment of the present invention. [Figure 3]FIG. 1 is a schematic diagram illustrating an example of how the current topography is measured by a distance meter in a hydraulic excavator according to a first embodiment of the present invention. [Figure 4] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (a display example of height data of the designed terrain). [Figure 5] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (a display example of height data of the current terrain). [Figure 6] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (a display example of difference data in height between the designed terrain and the current terrain). [Figure 7] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (a display example of a cross section of the current topography) [Figure 8] Explaining the principle behind the occurrence of unmeasurable areas [Figure 9] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (one example of a display of a field of view map) [Figure 10] FIG. 10 is an explanatory diagram illustrating an example of a calculation algorithm for the amount of slope of the current terrain by a controller provided in the hydraulic excavator according to the first embodiment of the present invention. [Figure 11] An example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (a display example of a tilt amount diagram) [Figure 12] 10 is a diagram showing an example of a guidance screen displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention (another example of displaying a tilt amount diagram). [Figure 13] 1 is a flowchart showing the overall procedure for executing a measurement process of the current topography by a controller provided in a hydraulic excavator according to a first embodiment of the present invention. [Figure 14] FIG. 10 is a diagram showing an example of an alarm displayed on a monitor provided in the hydraulic excavator according to the first embodiment of the present invention. [Figure 15] FIG. 10 is a diagram illustrating another example of an alarm displayed on the monitor provided in the hydraulic excavator according to the first embodiment of the present invention. [Figure 16] 1 is a flowchart showing details of a procedure for obstacle determination by a controller provided in a hydraulic excavator according to a first embodiment of the present invention. [Figure 17] 10 is a flowchart showing details of a data update procedure performed by a controller provided in a hydraulic excavator according to a first embodiment of the present invention. [Figure 18] 10 is a flowchart showing details of a procedure for displaying guidance by a controller provided in the hydraulic excavator according to the first embodiment of the present invention. [Figure 19] 10 is a flowchart showing details of an obstacle determination procedure performed by a controller provided in a hydraulic excavator according to a second embodiment of the present invention. [Figure 20] An example of a guidance screen displayed on a monitor provided in a hydraulic excavator according to a second embodiment of the present invention (one example of a display of a field of view map) DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] First Embodiment 1. Hydraulic excavator Fig. 1 is a side view showing the overall structure of a hydraulic excavator according to a first embodiment of the present invention. Hereinafter, the left side of Fig. 1 will be referred to as the front side of the hydraulic excavator (strictly speaking, the rotating body). The hydraulic excavator shown in the figure is configured to include a vehicle body 1 and a front working implement 2. The vehicle body 1 is configured to include a running body 3 and a rotating body 4.

[0011] 1-1.Running body The running body 3 is a foundation structure that enables the hydraulic excavator to travel under its own power. While a wheeled running body may be used, this embodiment illustrates a configuration in which a crawler-type running body is used. The running body 3 is composed of a track frame 5, idlers (driven wheels) 6, a running drive unit 7, sprockets (driving wheels) 8, and tracks (crawlers) 9. The track frame 5 is formed into an H-shape when viewed from above by a center frame 5a and a pair of parallel left and right side frames 5b connected to the center frame 5a. An idler 6 is rotatably supported at one end of the left and right side frames 5b, and a sprocket 8 is rotatably supported at the other end. The rotation shaft of the sprocket 8 is connected to the output shaft of the running drive unit 7. The running drive unit 7 is composed of a hydraulic motor for traveling and a reducer. A circular track 9 is looped between the idler 6 and the sprocket 8, and the running body 3 is self-propelled by driving the track 9 with the sprocket 8.

[0012] 1-2. Rotating body The rotating body 4 is rotatably mounted on the upper part of the running body 3, and is composed of a rotating frame 10, a cab 11, a counterweight 12, a machine room (engine room) 13, etc. The rotating frame 10 is the base frame of the rotating body 4, and is mounted on the upper part of the center frame 5a of the track frame 5 via a rotating ring 14. A rotating motor (not shown) is mounted on the rotating frame 10 near the rotating ring 14, and the output shaft of the rotating motor meshes with a gear provided on the rotating ring 14, causing the rotating body 4 to rotate relative to the running body 3. Although an electric motor can be used as the rotating motor, a hydraulic motor is used in this embodiment.

[0013] A cab 11 is provided at the front of the revolving frame 10 so as to be located on one side (the left side in this example) in the left-right direction of the front work implement 2. A machinery room 13 covered by a bonnet cover is provided behind the cab 11 on the revolving frame 10. A counterweight 12 is attached to the rear end of the revolving frame 10. The machinery room 13 houses a hydraulic system including a prime mover, a hydraulic pump driven by the prime mover, a control valve that controls the pressure oil from the hydraulic pump to hydraulic actuators (such as the boom cylinder 25), heat exchangers, tanks, various piping and wiring, etc. An electric motor may be used as the prime mover, but in this example, an engine (internal combustion engine) is used.

[0014] A monitor 15 (FIG. 2) is also provided inside the cab 11. The monitor 15 functions as a guidance device that displays various data to assist the operator in their operations. In this embodiment, the monitor 15 is equipped with a terrain measurement button 42 (FIG. 2) that commands measurement of the current terrain using a rangefinder S2 (described later). Operation of the terrain measurement button 42 inputs a measurement command signal, which triggers the controller 30 to calculate the measurement data of the current terrain using the rangefinder S2 and display it on the monitor 15. The terrain measurement button 42 may be a button (icon) displayed on the screen of the monitor 15 as shown in FIG. 4, or may be a mechanical switch such as a push button. If a mechanical switch is used, the terrain measurement button 42 does not need to be a component of the monitor 15, and may be attached to another structure (for example, a console box or an operating lever for operating the front work implement 2) located within reach of the operator sitting in the driver's seat.

[0015] 1-3. Front work equipment The front working machine 2 is attached to the revolving body 4 and is an articulated front working device including a working arm 21, a bucket (attachment) 24, a boom cylinder 25, an arm cylinder 26, and a bucket cylinder 27.

[0016] The working arm 21 is configured to include a boom 22 and an arm 23. The boom 22 is rotatably connected to the front part of the revolving unit 4 in the vertical direction, and the arm 23 is rotatably connected to the tip of the boom 22. A bucket 24 is rotatably attached to the tip of the arm 23. Both ends of a boom cylinder 25 are connected to the revolving unit 4 and the boom 22. Both ends of an arm cylinder 26 are connected to the boom 22 and the arm 23. The base end of a bucket cylinder 27 is connected to the arm 23, and the tip end is connected to the tip of the arm 23 and the bucket 24 via a link. The boom cylinder 25, arm cylinder 26, and bucket cylinder 27 are all hydraulic cylinders.

[0017] The front work implement 2 is also equipped with a reflector 28 that can be detected by a range finder S2 (described later). The reflector 28 is a reflective member for which the output of the range finder S2 (specifically, the intensity of an electrical signal obtained by photoelectrically converting reflected laser light received by the range finder S2) is a known value. The reflector 28 is preferably provided in at least one location among the tip of the arm 23 of the front work implement 2, the base end of the bucket 24, and the middle portion of the boom 22 in the longitudinal direction. In this embodiment, the reflector 28 is provided at the tip of the ventral side of the arm 23 of the front work implement 2 and the middle portion of the left side of the boom 22 in the longitudinal direction.

[0018] 1-4. Position sensors The hydraulic excavator shown in FIG. 1 is equipped with a position sensor S1 (FIG. 2) as a position information acquisition device that acquires position data of the vehicle body 1 in real time. The position sensor S1 is a positioning device such as an RTK-GNSS (Real Time Kinematic - Global Navigation Satellite System). The position sensor S1 acquires position data in a global coordinate system from an antenna (not shown) installed on the vehicle body 1. By installing two antennas, the controller 30 (described later) can also calculate the orientation data of the vehicle body 1 from the position data of the two antennas. The position of the vehicle body 1 acquired by the position sensor S1 is, strictly speaking, the position of the antenna installed on the vehicle body 1. However, this can be freely converted to a specific position of the vehicle body 1 (for example, the position of the rangefinder S2 or the center position of the vehicle body 1) using known dimensional data of the vehicle body 1. Although not specifically shown, a radio that receives correction data from a reference station GNSS (not shown) may also be installed on the hydraulic excavator. When this radio is used, the position data of the vehicle body 1 is corrected using the correction data received by the radio.

[0019] 1-5.Distance meter The hydraulic excavator shown in FIG. 1 is also equipped with a range finder S2 that measures distances to a plurality of ranging points on the current terrain around the vehicle body 1. In this embodiment, the range finder S2 uses LiDAR (Light Detection and Ranging). The range finder S2 emits a number of laser beams with optical axis angles shifted in the left-right direction (yaw direction) and the up-down direction (pitch direction), and measures the distance to each ranging point from the time it takes for the reflected laser beam to be received at each ranging point. From the output of the range finder S2, position data of each ranging point (point cloud) based on the position of the range finder S2 is obtained as measurement data. This range finder S2 obtains three-dimensional measurement data (point cloud data) of the terrain (shape of the earth's surface), and the range finder S2 functions as a terrain information acquisition device.

[0020] 2. Controller Figure 2 is a functional block diagram of the controller provided in the hydraulic excavator shown in Figure 1. The controller 30 shown in the figure is an on-board computer that displays and outputs measurement data of the current topography based on the output of the range finder S2 on the monitor 15, and is configured to include an input unit 31, a memory 32, a processor 33, and an output unit 34.

[0021] 2-1. Input section The input unit 31 is a signal input interface. In the example of Fig. 2, outputs from a position sensor S1, a distance meter S2, an MG system (machine guidance system) S3, a speedometer S4, and a key switch S5 are input to the controller 30 in real time via the input unit 31. If the input signals are analog signals, they are converted into digital signals by the input unit 31.

[0022] The MG system S3 is a type of computer, and in this embodiment, the MG system S3 is a computer separate from the controller 30, but the controller 30 may also have the functions of the MG system S3. The MG system S3 stores designed terrain data and map data for the construction site, outputs map data and designed terrain data for the vicinity of the hydraulic excavator (own machine), and inputs them to the controller 30. The designed terrain data and map data are, for example, 3D polygon data. However, the map data does not need to be 3D data for superimposing the current terrain and unmeasurable areas on the monitor 15 as described below, and may be 2D data such as a planar map or mesh map having only horizontal coordinate position data. Data input from the MG system S3 to the controller 30 can be configured to be executed in real time based on the output of the position sensor S1, for example, or can be executed in response to a request from the controller 30.

[0023] The speedometer S4 is a sensor that measures and outputs the vehicle speed (traveling speed) of the hydraulic excavator, and may be mechanical, electrical, or electronic. The key switch S5 is a switch that turns on and off the power supply and prime mover of the hydraulic excavator, and is provided in the operator's cab 11.

[0024] 2-2.Memory The memory 32 is a storage device and is appropriately configured with various storage media such as an HDD, RAM, ROM, and SSD. The memory 32 includes a main storage device 32a, which is a volatile memory, and an auxiliary storage device 32b, which is a non-volatile memory. The auxiliary storage device 32b of the memory 32 stores a display control program for the monitor 15 and various data required to execute the display control program. The various data stored in the auxiliary storage device 32b include measurement data of distance measurement points obtained by the rangefinder S2, and design topography data and map data of the construction site input from the MG system S3. The main storage device 32a temporarily stores various data input via the input unit 31, the display control program loaded from the auxiliary storage device 32b, measurement data of distance measurement points obtained by the rangefinder S2, and various data such as design topography data and map data of the construction site. The processor 33 executes various display processes according to the display control program loaded into the main storage device 32a.

[0025] Processor The processor 33 is an arithmetic processing device such as a CPU, and generates a display control signal and outputs it to the monitor 15 in accordance with a program loaded from the auxiliary storage device 32b of the memory 32 to the main storage device 32a. The functions executed by the processor 33 include an obstacle determination function F1, a data update function F2, a difference calculation function F3, a field of view map creation function F4, and a tilt amount calculation function F5. Each of these functions is executed by the processor 33 in accordance with the display control program loaded into the main storage device 32a. The obstacle determination function F1, data update function F2, difference calculation function F3, field of view map creation function F4, and tilt amount calculation function F5 will be described later.

[0026] 2-4. Output section 2, a display control signal is output from the controller 30 via the output unit 34, and the display control signal is input to the monitor 15. The monitor 15 displays messages such as alarms and graphics on the screen in response to the display control signal from the controller 30.

[0027] 2-5. Obstacle detection function The obstacle determination function F1 is a function that determines whether an obstacle (in this example, the front attachment 2) is overlapping within the measurement range of the rangefinder S2 when the rangefinder S2 measures the current terrain in order to obtain measurement data of the current terrain (point cloud data of the ground surface). In other words, it is a function that determines whether the laser light emitted toward the current terrain is being blocked by the front attachment 2. For example, if the front attachment 2 is overlapping within the measurement range of the rangefinder S2 as shown in FIG. 1, some laser light, such as laser light L1 in the lower region within the measurement range, will reach the ground surface, while other laser light, such as laser light L2 in the upper region, will be blocked by the front attachment 2 and will not reach the ground surface. In this case, the distance measurement point P1 measured by the laser light L1 is data that truly represents the current terrain, but the distance measurement point P2 measured by the laser light L2 is distance information for the front attachment 2 and is not data that truly represents the current terrain. As described above, the front attachment 2 is equipped with a reflector 28 with a known reflectivity for laser light, and the signal strength of the laser light reflected by the reflector 28 is known. Therefore, by determining whether the output signal of the range finder S2 for each distance measurement point contains a signal of a set intensity or more, the controller 30 can determine whether the front working implement 2 is within the measurement range of the range finder S2. The set intensity set for the output signal is a value set based on the known signal intensity of the laser light reflected by the reflector 28 (for example, a value set slightly lower than the known signal intensity).

[0028] In this embodiment, when a signal is input from the terrain measurement button 42, the controller 30 calculates measurement data of the current terrain based on the output of the range finder S2 only when the vehicle speed V of the hydraulic excavator measured by the speedometer S4 is less than the set speed V1. The set speed V1 is a value set from the perspective of ensuring a certain level of distance measurement accuracy by the range finder S2. In other words, when the vehicle speed V is equal to or greater than the set speed V1, a certain level of distance measurement accuracy cannot be expected, and the state is presumed to be unsuitable for acquiring measurement data of the current terrain. Therefore, the obstacle determination function F1 in this embodiment is configured to treat a case in which the vehicle speed V is equal to or greater than the set speed V1 as if an obstacle is present within the measurement range of the range finder S2, even if the obstacle is not present within the measurement range of the range finder S2. As will be described later using a flowchart, in this embodiment, even if the controller 30 is instructed to measure the terrain, if the range finder S2 determines that an obstacle is present, such as when it detects a reflector 28 between the current terrain and the range finder S2, the controller 30 stops measuring the current terrain. In other words, when the vehicle speed V is equal to or greater than the set speed V1, the controller 30 does not calculate the measurement data of the current terrain even if there are no obstacles within the measurement range of the rangefinder S2, and calculates the measurement data of the current terrain only when the vehicle speed V is less than the set speed V1, provided that there are no obstacles.

[0029] 2-6.Data update function The data update function F2 is a function that determines whether or not the measurement data of the distance measurement point measured by the rangefinder S2 recorded in the auxiliary storage device 32b of the memory 32 needs to be updated based on the measurement date and time and the amount of change, and updates the measurement data as necessary.

[0030] In the data update function F2, the controller 30 compares the current measurement data of the current terrain, which was measured by the rangefinder S2 and stored in the main memory device 32a when an operator inputs a terrain measurement command, with the most recent measurement data. The most recent measurement data refers to the measurement data for the corresponding position (i.e., the corresponding horizontal coordinates (e.g., longitude and latitude)) stored in the auxiliary memory device 32b (or the most recent measurement data if multiple measurement data from different times are stored), and is read from the auxiliary memory device 32b. The controller 30 updates (records) the measurement data in the auxiliary memory device 32b in the memory 32 only for distance measurement points where the difference dH between the current measurement data and the most recent measurement data is equal to or greater than a set value dH1. The difference dH between the current measurement data and the most recent measurement data is the amount of change in height of the distance measurement point (or mesh) corresponding to the horizontal coordinates (e.g., longitude and latitude). The set value dH1 is set from the perspective of grasping the general progress of terrain development, and is set to prevent excessive updating of the measurement data in the auxiliary memory device 32b due to slight changes, for example, caused by measurement errors. The set value dH1 can be set to a fixed value, or can be set as a percentage, such as 10% of the height data of the most recent measurement data. When setting the set value dH1 as a percentage, it can be selectively set between 5-30%, for example.

[0031] In the data update function F2, the controller 30 also compares the measurement dates and times of the current measurement data and the most recent measurement data for corresponding locations. The controller 30 updates the measurement data in the auxiliary storage device 32b (records the current measurement data) only for distance measurement points for which the elapsed time T from the measurement date and time of the most recent measurement data to the measurement date and time of the current measurement data is equal to or greater than a set time T1. The set time T1 is a value that is set arbitrarily to prevent the measurement data of the current topography in the auxiliary storage device 32b from being updated more frequently than necessary, and can be, for example, about one hour.

[0032] FIG. 3 is a schematic diagram illustrating an example of how the current terrain is measured using the range finder S2. In the figure, the current terrain CL is shown in a cross section cut by the operating plane of the front work implement 2 (a plane including the center lines of the arm cylinder 26 and the bucket cylinder 27). In the figure, the ground surface of the current terrain CL is shown by a solid line, and the ground surface of the design terrain DL is shown by a dashed line. When the current terrain CL is measured using the range finder S2 in the figure, measurement data (point cloud of the current terrain CL) of each ranging point of the range finder S2 is acquired. In other words, because the angle of the optical axis of each laser beam (the line connecting each ranging point and the range finder S2) relative to the range finder S2 is known, measuring the distance between the ranging point and the range finder S2 allows the positional data of the ranging point on the optical axis of each laser beam to be uniquely determined as measurement data (point cloud). The controller 30 converts the point cloud data of the current topography CL in the local coordinate system of the hydraulic excavator thus acquired into data in a coordinate system (e.g., a global coordinate system) of the map data based on the current position of the vehicle body 1 acquired by the position sensor S1. As a result, the coordinate data of each distance measurement point measured by the rangefinder S2 is associated with the map data based on the position data of the vehicle body 1 acquired by the position sensor S1. The measurement data of the current topography CL thus mapped on the map data is stored in the auxiliary storage device 32b of the memory 32 in accordance with the conditions described above based on the elapsed time and amount of change since the most recent measurement data.

[0033] 2-7.Differential calculation function The difference calculation function F3 is a function that calculates the difference H (Fig. 3) between the design terrain data and the measurement data of the current terrain CL, and displays it on the monitor 15. Based on the difference H calculated by the difference calculation function F3, the measurement data of the current current terrain CL, and the design terrain data, it is possible to display on the monitor 15 a graphic (Fig. 7) in which the outline of the design terrain DL is superimposed on a vertical cross section of the current terrain CL. It is also possible to display on the monitor 15 a graphic (Fig. 6) in which the data on the remaining excavation volume (difference H) until the creation of the design terrain DL is completed is expressed as gradation or numerical values ​​on the map data. The screen displayed by the difference calculation function F3 visually instructs the operator on the remaining excavation volume until the creation of the design terrain DL is completed.

[0034] 2-7-1. Display example (design terrain) FIG. 4 shows an example of a guidance screen displayed on the monitor 15, illustrating an example of the elevation data of the design terrain DL. The guidance screen in the figure displays icons such as a message field 41, a terrain measurement button 42, a design terrain display button 43, a current terrain display button 44, a difference display button 45, a cross-section display button 46, a field of view map display button 47, an inclination display button 48, and a display window 49. The guidance screen in FIG. 4 is displayed on the monitor 15 by operating the design terrain display button 43. The area displayed in the display window 49 is the area ahead of the hydraulic excavator that encompasses the measurement range of the rangefinder S2, and is divided into multiple meshes by borders aligned horizontally in two directions. The elevation data of the design terrain DL is displayed numerically for each mesh. The higher the elevation data value, the higher the point. In the example of FIG. 4, it can be seen that the design terrain DL ahead of the hydraulic excavator is an uphill slope, as shown in FIG. 3. When multiple distance measurement points of the rangefinder S2 belong to one mesh, the controller 30 calculates the statistical value (average value, median value, etc.) of the heights of the multiple distance measurement points as height data for the mesh.

[0035] In addition, although not limited to this, in Figure 4 the mesh is color-coded according to the height value. In this specification, "color coding" includes the expression of shades of the same color. In the example in Figure 4, the higher the point, the darker the color used, and if the terrain is uniformly sloping, the color change will also be uniform.

[0036] 2-7-2. Display example (current terrain) Figure 5 is a diagram showing an example of a guidance screen displayed on the monitor 15, and is an example of a display of height data for the current terrain CL. The guidance screen in Figure 5 is a screen displayed on the monitor 15 by operating the current terrain display button 44. The area displayed in the display window 49 is the same as that in Figure 4, and the height data for the current terrain CL is displayed as a numerical value for each mesh. The height data numerical values ​​and mesh color coding shown in Figure 5 correspond to the example in Figure 4.

[0037] 2-7-3. Display example (difference between design topography and current topography) Fig. 6 is a diagram showing an example of a guidance screen displayed on the monitor 15, and is an example of a display of height difference data between the design terrain DL and the current terrain CL. The guidance screen in Fig. 6 is a screen displayed on the monitor 15 by operating the difference display button 45. The area displayed in the display window 49 is the same area as in Figs. 4 and 5, and height difference data between the design terrain DL and the current terrain CL (in this example, the difference between the data in Figs. 4 and 5) is displayed numerically for each mesh. The larger the numerical value in Fig. 6, the greater the difference in height between the design terrain DL and the current terrain CL, and in the examples of Figs. 4 to 6, it can be seen that the difference between the design terrain DL and the current terrain CL is relatively large in areas far forward from the hydraulic excavator.

[0038] Also, although not limited to this, in Figure 6, meshes are color-coded (including shades of the same color) according to the difference in altitude between the design terrain DL and the current terrain CL. In the example of Figure 6, the meshes with a greater difference in altitude between the design terrain DL and the current terrain CL are colored darker, and the operator is visually informed by the darker color of the points that should be cut to bring the current terrain CL closer to the design terrain DL.

[0039] 2-7-4. Display example (cross section of current topography) FIG. 7 is a diagram showing an example of a guidance screen displayed on the monitor 15, and is an example of a display of a cross section of the current terrain CL. The guidance screen in FIG. 7 is a screen displayed on the monitor 15 by operating the cross section display button 46. The terrain cross section displayed in the display window 49 is a vertical cross section cut by the operating plane of the front working implement 2, as in the schematic diagram of FIG. 3. In this figure, in addition to the ground surface of the current terrain CL (solid line), the ground surface of the design terrain DL (dashed line) is also shown, and the difference between the current terrain CL and the design terrain DL is simulated. The cross section of the current terrain CL can be displayed by calculating the intersection line between the ground surface of the current terrain CL calculated from the measurement data and the operating plane of the front working implement 2. Similarly, the cross section of the design terrain DL can be displayed by calculating the intersection line between the ground surface of the design terrain DL calculated from the design terrain data and the operating plane of the front working implement 2. In FIG. 7, a scale I for grasping the height of the terrain from data is displayed superimposed on the undulating portions of the current terrain CL and the design terrain DL. The height of scale I corresponds to the numerical value used to evaluate the height of the terrain in Figures 4 and 5. The color coding of the height on scale I also corresponds to the color coding of the meshes in Figures 4 and 5.

[0040] 2-8. Viewpoint map creation function The field of view map creation function F4 is a function that creates a field of view map (Figure 9) based on the output of the rangefinder S2 and displays it on the monitor 15. The field of view is the measurement range of the rangefinder S2. The field of view map displays the area where the terrain is currently being measured by the rangefinder S2. This field of view map also displays areas within the measurement range of the rangefinder S2 where the terrain is not currently being measured (areas where the height cannot be measured, hereinafter referred to as "unmeasurable areas").

[0041] An example of the calculation of the field of view map by the controller 30 will be described below. The controller 30 first calculates the horizontal coordinates (e.g., longitude and latitude) of the measurement data for each ranging point based on the current position data of the vehicle body 1 acquired by the position sensor S1, the map data read from the auxiliary storage device 32b of the memory 32, and the output of the rangefinder S2. This procedure can be shared with the process of mapping the current topography data onto the map data by the data update function F2. Specifically, based on the position data of the vehicle body 1 acquired by the position sensor S1, the coordinate data of each ranging point measured by the rangefinder S2 is associated with the map data.

[0042] Next, the controller 30 calculates the horizontal distance W between adjacent distance measurement points for each of the distance measurement points of the rangefinder S2. The distance W calculated here is the horizontal distance (i.e., in a planar view) between two distance measurement points where two adjacent laser beams are reflected, either vertically or horizontally, and can be calculated from the horizontal coordinates of the two distance measurement points. The controller 30 compares each of the horizontal distances between adjacent distance measurement points thus calculated with a set distance W1. The set distance W1 is an arbitrarily set value, but as an example, the length of one side or the length of the diagonal of one of the meshes shown in FIG. 4 can be used.

[0043] The controller 30 then records the height data calculated based on the output of the rangefinder S2 for distance measurement points whose interval W between adjacent distance measurement points is equal to or less than the set interval W1 in the memory 32 as measurement data of the current terrain CL and displays it on the monitor 15. At this time, the controller 30 can also display map data on the monitor 15 and overlay the measurement data of the current terrain CL on the map data. The area where the height data is displayed is presumed to be the area where the current terrain CL was actually measured. The controller 30 also records in the memory 32 and displays on the monitor 15 a message indicating that the area where the interval W between adjacent distance measurement points is greater than the set interval W1 is an unmeasurable area where height measurement is impossible. At this time, the controller 30 can also display map data on the monitor 15 and overlay the unmeasurable area on the map data.

[0044] 2-8-1. Unmeasurable area Figure 8 is an explanatory diagram of the principle behind the occurrence of unmeasurable areas. First, the angle between adjacent laser optical axes on the top and bottom or left and right of the rangefinder S2 and the size of the mesh in Figure 4 and other figures are set under the assumption that if the shape of the terrain to be measured is monotonous, the horizontal distance between adjacent measurement points will be shorter than the actual distance corresponding to the length of one side of the mesh. As shown in Figure 8, for example, if adjacent laser beams L3 and L4 are irradiated from the rangefinder S2 to measurement points P3 and P4 on a monotonous uphill slope of the current terrain CL, the distance W between measurement points P3 and P4 will be shorter than the distance corresponding to one side of the mesh. In this case, no area (mesh) that cannot be measured will occur between adjacent measurement points P3 and P4.

[0045] However, if there is a depression Z in the measurement range as shown in Figure 8, the horizontal distance S between measurement points P5 and P6 measured by adjacent laser beams L5 and L6 will increase. In this case, if the interval W between adjacent measurement points P5 and P6 is longer than the distance corresponding to one side of a mesh, an area (mesh) where measurement is not possible may occur between measurement points P5 and P6. Since the position of each measurement point on the map data can be determined, it is possible to identify on the map a mesh with no measurement points as an unmeasurable area.

[0046] 2-8-2. Display example (field of view diagram) Figure 9 is a diagram showing an example of a guidance screen displayed on monitor 15, and is an example of a display of a field of view map. The guidance screen in Figure 9 is a screen displayed on monitor 15 by operating field of view map display button 47. The area displayed in display window 49 is the same area as in Figures 4 to 6, and the elevation data of each point on the current terrain CL is displayed numerically and color-coded for each mesh, just like in Figure 5.

[0047] In addition, in Figure 9, the measurement range currently being measured by the rangefinder S2 is represented by indicator lines B1 and B2. The current measurement points are concentrated in the area between indicator lines B1 and B2, and the meshes between indicator lines B1 and B2 that display height data represent the points where height is currently being measured. Meshes that are within the measurement range between indicator lines B1 and B2 but that are not measured, such as depression Z shown in Figure 8, are displayed as unmeasurable area A. Figure 9 illustrates an example in which the meshes representing unmeasurable area A are displayed in white and the height values ​​are not displayed.

[0048] 2-9. Inclination amount calculation function The slope calculation function F5 calculates and displays the slope of each measurement point of the current terrain CL based on the measurement data of each measurement point of the current terrain CL. The slope is, for example, the angle of the ground surface with respect to the horizontal plane; the smaller the slope of the ground surface, the closer to horizontal it is, and the larger the slope of the ground surface, the closer to vertical it is. As will be described later, the controller 30 calculates the slope of each measurement point (mesh in this example) based on the height data of each measurement point of the current terrain CL, and outputs a slope map (Figures 11 and 12) to the monitor 15, overlaid on the map data.

[0049] 2-9-1. Tilt amount calculation algorithm Figure 10 is an explanatory diagram of an example of an algorithm for calculating the slope of the current terrain using the controller 30. This diagram shows nine meshes (M11-M13, M21-M23, M31-M33) with three rows and three columns extracted from the measurement data of the current terrain CL measured by the rangefinder S2. The heights of meshes M11-M13, M21-M23, and M31-M33 are H11-H13, H21-H23, and H31-H33, respectively, with the horizontal spacing between the meshes being Dx and the vertical spacing being Dy. The slope IA of the area represented by these nine meshes can be calculated using the least squares method as follows:

[0050] IA=√(Sx 2 +Sy 2 )...(Formula 1) Sx=(H11+H21+H31-(H13+H23+H33)) / 6Dx Sy=(H11+H12+H13-(H31+H32+H33)) / 6Dy

[0051] For example, the controller 30 can calculate the amount of tilt for each mesh by shifting the nine meshes for which the amount of tilt is to be calculated by one mesh at a time and finding the value of IA using the above formula 1.

[0052] 2-9-2. Display example (inclination amount diagram-1) FIG. 11 is a diagram showing an example of a guidance screen displayed on the monitor 15, and is an example of a slope map. The guidance screen in FIG. 11 is a screen displayed on the monitor 15 by operating the slope display button 48. The area displayed in the display window 49 is the same as that shown in FIGS. 4-6 and 9, and the slope is displayed in different colors for each mesh. In the example shown in FIG. 11, meshes with smaller slopes are displayed in lighter colors, while meshes with larger slopes are displayed in darker colors. For example, areas with a gentle slope that is nearly horizontal are displayed in lighter colors overall, while areas with large undulations are displayed in darker colors overall. Therefore, whether the ground surface is nearly horizontal or has a steep slope, areas with small surface irregularities will have less color change on the slope map display. Also, unlike the altitude display shown in FIG. 5, in the slope map shown in FIG. 11, areas with a gentle slope even at high elevations are displayed in lighter colors, and conversely, areas with a steep slope even at low elevations are displayed in darker colors.

[0053] If an unmeasurable area A exists, it is not possible to simply calculate the amount of tilt IA using the above formula 1 in the unmeasurable area A. For this reason, in the example of Figure 11, the amount of tilt is not displayed for the unmeasurable area A, and it is displayed in white, just like in Figure 9.

[0054] 2-9-3. Display example (inclination amount diagram-2) Figure 12 is a diagram showing an example of a guidance screen displayed on monitor 15, and is another example of the display of a slope map. The second example of the slope map shown in Figure 12 is also displayed on monitor 15 by operating slope display button 48, for example. The example in Figure 12 differs from the example in Figure 11 in that the height data (Figure 5) of the current terrain CL is displayed in the mesh area of ​​display window 49, and a slope map TD corresponding to the measurement range of rangefinder S2 is displayed superimposed on the mesh area.

[0055] In this embodiment, the tilt map TD corresponding to the current measurement range of the rangefinder S2 can be displayed in mesh units as shown in FIG. 11, but FIG. 12 shows an example in which it is displayed in high resolution in units of distance measurement points. The tilt calculation algorithm can calculate the value of IA by applying the height data of nine distance measurement points measured using nine laser beams arranged in three rows and three columns adjacent vertically and horizontally to the above equation 1. Note that the value of Dx used in the above equation 1 can be, for example, a statistical value (e.g., average value) of the left-right spacing of the nine distance measurement points. Similarly, the value of Dy can be, for example, a statistical value (e.g., average value) of the front-to-back spacing of the nine distance measurement points.

[0056] Figure 12 also illustrates a case where there is an unmeasurable area A within the current measurement range. The unmeasurable area A does not display any tilt amount information and is displayed in white. The display area of ​​the tilt amount diagram TD (i.e., the current measurement range) may be displayed more simply, as shown by the indicator lines B1 and B2 in Figure 9.

[0057] 3.Operation -guidance- Fig. 13 is a flowchart showing the overall procedure for executing processing for measuring the current topography by the controller 30. The flowchart shown in Fig. 13 is started by being triggered, for example, by the power-on of the hydraulic excavator (power being supplied to the controller 30) based on a signal from the key switch S5 (Fig. 2). The controller 30 constantly executes the flow shown in the same figure while the power of the hydraulic excavator is on.

[0058] Step S10 13 starts, the controller 30 first determines whether the power to the hydraulic excavator remains on based on a signal from the key switch S5 (step S10). If the key switch S5 is turned off, the controller 30 executes termination processing and ends the flow of FIG.

[0059] Step S20 If the key switch S5 is on, the controller 30 determines whether the operator has issued an instruction to measure the current topography CL (step S20). If the operator has not operated the topography measurement button 42 and a signal instructing measurement of the current topography CL has not been input from the monitor 15, the controller 30 returns the procedure from step S20 to step S10.

[0060] Step S30 When the operator operates the terrain measurement button 42 and a signal instructing measurement of the current terrain CL is input from the monitor 15, the controller 30 temporarily stores the latest output values ​​of each sensor input in real time in the main storage device 32a of the memory 32 (step S30). The sensor outputs temporarily stored here are, for example, the outputs of the position sensor S1, the distance meter S2, the MG system S3, and the speedometer S4.

[0061] Step S40 After temporarily storing the necessary sensor outputs in response to instructions from the operator, the controller 30 determines whether an obstacle (front working implement 2) is present within the measurement range of the range finder S2 based on the output of the range finder S2 (step S40). The procedure in step S40 corresponds to the obstacle determination function F1 described above. The procedure in step S40 will be described in detail later (FIG. 16).

[0062] Step S50 If it is determined that an obstacle overlaps within the measurement range of the range finder S2, the controller 30 outputs a signal to the monitor 15, causes the monitor 15 to display an alarm, and returns the procedure to step S10 (step S50).

[0063] Fig. 14 is a diagram showing an example of an alarm display. As will be described later, if the front working implement 2 overlaps the measurement range of the distance meter S2, it is determined in step S40 that "an obstacle is present." The display example in Fig. 14 is an example in which an alarm message is displayed to notify the operator that the front working implement 2 is obstructing the measurement of the current topography CL. A message saying "Raise the front" is also displayed in the message field 41, urging the operator to move the front working implement 2 out of the measurement range of the distance meter S2.

[0064] 15 is a diagram showing another example of an alarm display. In this embodiment, when the hydraulic excavator is moving at a certain speed or above, it is treated in step S40 as if there is an obstacle, and it is determined that "an obstacle is present." The display example of FIG. 15 shows an example in which an alarm message saying "Please stop" is output in message field 41 in such a situation, urging the operator to perform an operation to stop the vehicle body 1.

[0065] The examples in Figures 14 and 15 show examples in which an alarm message is output, but it is also possible to have the controller 30 input a command signal to a speaker or the like provided on the monitor 15 or installed separately, and have an alarm sound output together with the alarm message.

[0066] Step S60 If it is determined that no obstacles are overlapping within the measurement range of the range finder S2, the controller 30 executes measurement (actual measurement) of the current terrain CL and temporarily stores the current output values ​​of the various sensors input in real time in the main memory device 32a (step S60). In this measurement procedure, the controller 30 temporarily stores the measurement data of each distance measurement point of the current terrain CL together with the measurement date and time data in the main memory device 32a. Note that in this embodiment, while measuring the current terrain CL in step S60, the controller 30 applies an interlock to disable operation of the hydraulic excavator. At that time, for example, as shown in FIG. 5, a message informing the operator of the current situation, such as "Vehicle operation is not permitted during terrain measurement," is displayed in the message field 41 of the guidance screen on the monitor 15.

[0067] Step S70 After measuring the current topography CL, the controller 30 executes an update process for the measurement data of the current topography CL stored in the auxiliary storage device 32b of the memory 32 (step S70). The procedure of step S70 corresponds to the data update function F2 described above. The procedure of step S70 will be described in detail later (FIG. 17).

[0068] Step S80 After updating the measurement data database, the controller 30 displays various information about the current measurement range of the rangefinder S2 on the monitor 15 in the format selected by the operator, and returns the procedure to step S10 (step S80). In this step S80 procedure, the difference calculation function F3, field of view map creation function F4, tilt amount calculation function F5, etc. are executed as appropriate depending on the operator's selection. The procedure of step S80 will be described in detail later (FIG. 18).

[0069] As described above, in this embodiment, the controller 30 does not display the current terrain CL in real time, but rather uses a measurement instruction input by the operator when he operates the terrain measurement button 42 as a trigger to calculate the measurement data of the current terrain CL and display it on the monitor 15.

[0070] -Obstacle detection- FIG. 16 is a flowchart showing details of the procedure for obstacle determination (step S40) of FIG. 13 by the controller 30.

[0071] Step S41 When the procedure of step S40 starts, the controller 30 determines whether or not a reflector 28 is detected between the current terrain CL and the rangefinder S2 based on the output of the rangefinder S2 read in step S30 (step S41). As described above, whether or not the reflector 28 is detected can be determined by comparing the signal strength of each laser beam reflected at each distance measurement point and detected by the rangefinder S2 with a set strength, and determining whether or not a signal strength equal to or greater than the set strength is detected. If the output of the rangefinder S2 includes a signal equal to or greater than the set strength, the controller 30 determines that the front working implement 2 is overlapping within the measurement range of the rangefinder S2, ends the flow of FIG. 16 (advances to step S50 of FIG. 13), and outputs an alarm (for example, FIG. 14).

[0072] Step S42 If the output of the rangefinder S2 does not include a signal of equal to or greater than the set intensity, the controller 30 determines whether the vehicle speed V is less than the set speed V1 based on the output of the vehicle speedometer S4 read in step S30 (step S42). If the vehicle speed V is equal to or greater than the set speed V1, the controller 30 ends the flow of FIG. 16 (advancees to step S50 of FIG. 13) and outputs an alarm (for example, FIG. 15). In this embodiment, even if the front working implement 2 does not overlap within the measurement range of the rangefinder S2, if the vehicle speed V is equal to or greater than the set speed V1 and the situation is not suitable for measuring the current topography CL, the situation is treated as if there is an obstacle within the measurement range of the rangefinder S2 and an alarm is output.

[0073] If the output of the rangefinder S2 does not include a signal of a set intensity or higher and the vehicle speed V is less than the set speed V1, it is estimated that there are no obstacles and the conditions are suitable for measuring the current terrain CL. In this case, the controller 30 ends the flow in Figure 16 (advances to step S60 in Figure 13) and measures the current terrain CL.

[0074] -Data update- FIG. 17 is a flowchart showing details of the procedure for updating data (step S70) of FIG. 13 by the controller 30.

[0075] Step S71 When the procedure of step S70 starts, the controller 30 converts the current measurement data of the current topography CL temporarily stored in step S60 into data in the coordinate system of the construction site (for example, the global coordinate system) based on the position data of the hydraulic excavator at the same time (step S71). In this embodiment, the construction site is divided into a large number of meshes (FIG. 4) in the coordinate system of the construction site (for example, the global coordinate system), and the measurement data by the rangefinder S2 is converted into height data for the meshes. When multiple measurement points belong to the same mesh, statistical values ​​(average value or median value) can be calculated as height data for the mesh.

[0076] Step S72 After converting the current measurement data into the on-site coordinate system, the controller 30 determines, based on the coordinate data of the measurement data, whether some or all of the meshes of the current measurement data have been measured in the past (step S72). If no mesh measurement data is stored in the auxiliary storage device 32b and all meshes of the current measurement data have not been measured, the controller 30 proceeds to the data update procedure in step S77. Conversely, if measurement data for at least one mesh is stored in the auxiliary storage device 32b, the controller 30 proceeds to the procedure in step S73.

[0077] Step S73 If at least a portion of the measurement range of the current measurement data overlaps with an area that has already been measured, the controller 30 reads the measurement date and time of the most recent measurement data whose position corresponds to the current measurement data from the auxiliary memory device 32b and temporarily stores it in the main memory device 32a (step S73).

[0078] Step S74 Next, the controller 30 calculates the elapsed time T by taking the difference between the measurement dates and times of the current measurement data and the most recent measurement data, which correspond to each other in position, and determines whether the elapsed time T is less than the set time T1 read from the auxiliary storage device 32b (step S74). If the elapsed time T is equal to or greater than the set time T1, the controller 30 proceeds to the data update procedure in step S77. If the elapsed time T is less than the set time T1, the controller 30 proceeds to the procedure in step S75.

[0079] Step S75 If the elapsed time T is less than the set time T1, the controller 30 calculates the difference dH in height data between the current measurement data and the most recent measurement data that correspond to each other in position (step S75).

[0080] Step S76 Next, the controller 30 determines whether the difference dH calculated in step S75 is less than the set value dH1 read from the auxiliary storage device 32b (step S76). If the difference dH is equal to or greater than the set value dH1, the controller 30 proceeds to the data update procedure in step S77. If the difference dH is less than the set value dH1, the controller 30 ends the flow of FIG. 17 without updating the measurement data in the auxiliary storage device 32b, and proceeds to step S80 (FIG. 13).

[0081] Step S77 If the determinations in steps S72, S74, and S76 are not satisfied, the controller 30 associates the current measurement data (height data for each mesh and each ranging point) obtained in this measurement with the measurement date and time and records them in the auxiliary storage device 32b of the memory 32 (step S77). That is, if all meshes of the measurement data obtained in this measurement have not yet been measured, if a set time T1 or more has elapsed since the previous measurement, or if the difference dH from the previous measurement data is a set value dH1 or more, the measurement data in the auxiliary storage device 32b is updated. After updating the measurement data in the auxiliary storage device 32b in this way, the controller 30 ends the flow of FIG. 17 and proceeds to step S80 (FIG. 13).

[0082] The measurement data of the unmeasurable area A' (FIG. 11, etc.) is distinguished from the measurement data of the current topography CL, and is not reflected in the measurement data of the current topography CL in the auxiliary storage device 32b.

[0083] -Display processing- 13 by the controller 30 (step S80). When the procedure of step S80 starts, the controller 30 determines the display mode selected by the operator on the guidance screen of the monitor 15 (steps S81-S86). Specifically, based on a signal from the monitor 15, the controller 30 determines which of the design terrain display button 43, current terrain display button 44, difference display button 45, cross section display button 46, field of view map display button 47, and slope display button 48 has been selected. The controller 30 then displays data corresponding to the operation on the monitor 15 in a display mode corresponding to the operation (steps S81a-S86a).

[0084] Specifically, if the design terrain display button 43 is operated, the controller 30 outputs a display control signal to the monitor 15 to display data of the design terrain DL (e.g., Figure 4) (steps S81, S81a). If the current terrain display button 44 is operated, the controller 30 outputs a display control signal to the monitor 15 to display measurement data of the current terrain CL (e.g., Figure 5) (steps S82, S82a). If the difference display button 45 is operated, the controller 30 outputs a display control signal to the monitor 15 to display data of the difference dH between the design terrain DL and the current terrain CL (e.g., Figure 6) (steps S83, S83a). If the cross-section display button 46 is operated, the controller 30 outputs a display control signal to the monitor 15 to display a cross-section of the design terrain DL and the current terrain CL (e.g., Figure 7) (steps S84, S84a). If the field of view map display button 47 is operated, the controller 30 outputs a display control signal to the monitor 15 to display and output a field of view map (e.g., Fig. 9) (steps S85, S85a). If the tilt display button 48 is operated, the controller 30 outputs a display control signal to the monitor 15 to display and output a tilt amount map (e.g., Fig. 11 or 12) (steps S86, S86a).

[0085] After executing any of the procedures in steps S81a-86a, the controller 30 determines whether the operator has performed an operation to end the measurement (step S87), and if the operation to end the measurement has not been performed, the procedure returns to step S81. The operation to end the measurement can be determined, for example, by identifying that the end button FB (FIG. 4) displayed on the guidance screen of the monitor 15 has been operated, based on a signal from the monitor 15. If the operator has performed an operation to end the measurement, the controller 30 ends the flow in FIG. 18 and returns the procedure to step S10 (FIG. 13).

[0086] -effect- (1) According to this embodiment, as described above, if an unmeasurable area A whose height cannot be measured exists within the measurement range based on the output of the rangefinder S2, the unmeasurable area A is displayed on the monitor 15. As described above, according to this embodiment, the operator can clearly confirm not only the area currently being measured by the rangefinder S2 but also areas that have not yet been measured through the guidance display on the monitor 15, and can grasp the areas that truly represent the current topography CL.

[0087] Also, there is a type of guidance that generally displays the position of the bucket tip together with the design terrain on a monitor in real time. However, in order to obtain basic information for calculating the position of the bucket tip, such guidance display requires an inclination sensor (e.g., an IMU) that detects the inclination angle of the vehicle body and multiple angle sensors that detect the angles of the boom, arm, and bucket. In contrast, the present embodiment does not require an inclination sensor or angle sensor to display the guidance screen, which has the advantage of reducing the number of parts and manufacturing costs of the hydraulic excavator. (2) Furthermore, by displaying the unmeasurable area A on the monitor 15 in a state where it is superimposed on the map data, the position of the unmeasurable area A on the map can be accurately notified to the operator. However, as long as the above essential effect (1) is obtained, the function of displaying the unmeasurable area A overlaid on the map data is not essential. For example, when displaying the unmeasurable area A in the local coordinate system, the position sensor S1 and map data are not necessarily required.

[0088] (3) The difference dH between the design topography DL and the current topography CL (measured topography) is displayed on the monitor 15, making it possible to confirm the amount of excavation required to create the design topography DL and to easily grasp the progress of the creation work. By displaying the difference dH in a mesh display (plan view) as shown in Figure 6, the distribution of the difference dH can be presented to the operator in an easy-to-understand manner. Furthermore, by displaying the difference dH in a cross section as shown in Figure 7, the current topography CL relative to the design topography DL can be visually presented to the operator.

[0089] (4) By installing the reflector 28 on the front working implement 2, it is possible to determine whether the front working implement 2 overlaps within the measurement range of the rangefinder S2. If the front working implement 2 overlaps within the measurement range of the rangefinder S2, an alarm can be displayed and output on the monitor 15 to indicate that the front working implement 2 is interfering with the measurement of the current terrain CL. This makes it possible to prompt the operator to move the front working implement 2 out of the measurement range of the rangefinder S2 when measuring the current terrain CL. By moving the front working implement 2 out of the measurement range of the rangefinder S2 in this way, it is possible to avoid the front working implement 2 interfering with the measurement of the current terrain CL. By truly measuring the current terrain CL without measuring the distance from the front working implement 2, the operator can make a reasonable judgment on the success of the terrain creation.

[0090] (5) The reflector 28 is provided at the tip of the arm 23 of the front working implement 2 and at the longitudinal middle of the boom 22, so when the front working implement 2 overlaps within the measurement range of the range finder S2, the front working implement 2 can be reasonably detected by the range finder S2. This makes it possible to reasonably eliminate the influence on terrain measurement caused by the front working implement 2 interfering with the measurement range of the range finder S2.

[0091] (6) If the current terrain CL is displayed on the monitor 15 in real time based on measurement data input from the rangefinder S2 as needed, when the front work implement 2 moves around within the measurement range of the rangefinder S2, the measurement data of the front work implement 2 is reflected in the display, and the current terrain CL may become unclear. Also, when operating the front work implement 2 while looking at the display, the front work implement 2 usually overlaps the measurement range of the rangefinder S2, so in order to check the current terrain CL, the front work implement 2 must be moved away from the area to be checked and the display must be checked again. Also, displaying the current terrain CL in real time places a load on the controller 30.

[0092] In contrast, in this embodiment, the current terrain CL is not displayed in real time. Instead, the current terrain CL is measured and displayed on the monitor 15 in response to a measurement instruction input by operating the terrain measurement button 42. In other words, the operator can measure and check the current terrain CL at any time. Therefore, for example, if the operator wants to check the progress of the current terrain CL during construction work, the operator can stop the construction, move the front attachment 2 out of the measurement range of the rangefinder S2, and then manually issue a measurement instruction. This procedure allows the operator to check the current terrain CL timely and accurately. Even if the operator forgets to move the front attachment 2 out of the measurement range of the rangefinder S2 during terrain measurement, the operator is notified that the front attachment 2 is within the measurement range of the rangefinder S2, as described above. This rationally prevents the front attachment 2 from affecting the measurement data of the current terrain CL. Furthermore, compared to displaying the current terrain CL in real time, displaying the current terrain CL at any time desired by the operator reduces the load on the controller 30.

[0093] In addition, compared to a screen that displays the positional relationship between the bucket and the design terrain in real time, a simple guidance screen that statically displays the relationship between the current terrain CL and the design terrain DL is presented to the operator, as in the screen shown in Figure 7. By displaying a simple, static guidance screen that avoids displaying more information than necessary, the operator can be informed of the progress of the work in an easy-to-understand manner.

[0094] However, as long as the above-mentioned essential effect (1) is obtained, the measurement range and the unmeasurable area A may be displayed in real time.

[0095] (7) In this embodiment, the measurement data of the current terrain CL is calculated only when the vehicle speed V is less than the set speed V1, and the current terrain CL is not measured when the vehicle speed V is equal to or greater than the set speed V1. While the reliability of the measurement data of the rangefinder S2 can be reduced when traveling at a high speed or faster, the reliability of the measurement data of the current terrain CL can be ensured by measuring the current terrain CL only when the vehicle speed V is less than the set speed V1.

[0096] However, as long as the above-mentioned essential effect (1) is obtained, the calculation of the measurement data of the current topography CL may be performed regardless of the vehicle speed V.

[0097] (8) When the current topography CL is newly measured, the data in the memory 32 (auxiliary storage device 32b) is updated only for distance measurement points where the difference dH from the most recent measurement data is equal to or greater than the set value dH1. Compared to replacing unchanged measurement data with existing data, updating only measurement data that has a certain degree of change from the existing data (including measurement data from the first measurement) can reduce the load on the controller 30 associated with data communication and storage for data updates.

[0098] However, as long as the above-mentioned essential effect (1) is obtained, the measurement data of the current topography CL may be updated regardless of the difference dH.

[0099] (9) Because the operator can visually check the current topography CL from the cab 11, it is expected that the current topography CL will be checked using measurement data at each stage of the construction work. Therefore, there is not necessarily a high need to update the measurement data excessively for areas where the previous measurement has not been performed recently.

[0100] Therefore, in this embodiment, when the current topography CL is newly measured, the data in the memory 32 (auxiliary storage device 32b) is updated only for distance measurement points for which the elapsed time T from the measurement date and time of the most recent measurement data is equal to or greater than the set time T1. By avoiding excessive data updates in this way, the load on the controller 30 associated with data communication and storage for data update processing can be reduced.

[0101] However, even if the above-mentioned measurement has been taken recently, if data needs to be updated for an area where a certain level of change in the progress of development is observed, the measurement data may be updated regardless of the time elapsed since the last measurement.

[0102] (10) In this embodiment, the amount of slope of the current topography CL can be superimposed on the map data and displayed on the monitor 15, as shown in Figures 11 and 12. In this case, the amount of slope of the current topography CL is not only useful as a reference for determining the quality of the current topography CL, but also makes it possible to know, for example, the amount of slope of the ground on which the hydraulic excavator touches down, and to inform the operator of the gradient of the area to which the vehicle body 1 is moving.

[0103] However, as long as the above essential effect (1) is obtained, the function of displaying the gradient map is not essential.

[0104] (11) As explained using Figure 18, in response to the operator's display switching operation, the measurement data of the current topography CL can be presented in various forms, such as a mapping display of the difference dH (Figure 6), a cross-sectional display (Figure 7), a field of view map (Figure 9), and a slope map (Figures 11 and 12). This allows the operator to flexibly grasp the current state of the construction work by checking the current topography CL in one or more desired forms.

[0105] Second Embodiment In the first embodiment, an example was described in which, if the front working implement 2 overlaps within the measurement range of the rangefinder S2, an alarm is output without measuring the current terrain CL, and the operator is prompted to move the front working implement 2 out of the measurement range. In contrast, in the second embodiment, measurement of the current terrain CL can be performed even if the front working implement 2 overlaps within the measurement range of the rangefinder S2, and areas in which the current terrain CL cannot be measured by the front working implement 2 are displayed on the field of view map as unmeasurable areas A.

[0106] FIG. 19 is a flowchart showing details of the procedure of obstacle determination (step S40) of FIG. 13 by the controller 30 in the second embodiment. As shown in FIG. 19, in this embodiment, the procedure of reflector detection (step S41) in the first embodiment is omitted, and when a command to measure the current terrain CL is issued, it is simply determined whether the vehicle speed V is less than the set speed V1 (step S42). If the vehicle speed V is equal to or greater than the set speed V1, the controller 30 ends the flow of FIG. 19 (advances to step S50 of FIG. 13) and outputs an alarm (e.g., FIG. 15). Conversely, if the vehicle speed V is less than the set speed V1, the controller 30 ends the flow of FIG. 16 (advances to step S60 of FIG. 13) and measures the current terrain CL.

[0107] Fig. 20 is an example of a guidance screen (field of view map) displayed on the monitor 15 in the second embodiment. The guidance screen in Fig. 20 is a screen displayed on the monitor 15 by operating the field of view map display button 47, and is a diagram equivalent to the field of view map of the first embodiment shown in Fig. 9. In Fig. 20, it is assumed that the front working implement 2 overlaps the measurement range of the rangefinder S2, and in addition to the unmeasurable area A due to the terrain caused by the depression Z (Fig. 8), an unmeasurable area A' due to the front working implement 2 is displayed within the current measurement range of the rangefinder S2 represented by the indication lines B1 and B2.

[0108] The unmeasurable area A' caused by the front work implement 2 can be identified by detecting the reflector 28 and estimating the position of the front work implement 2 within the measurement range of the rangefinder S2, as in the first embodiment. Furthermore, the front work implement 2 is discontinuous (floating) or overhanging from the ground surface as viewed from the rangefinder S2. Taking this into consideration, for example, by comparing two distance measurement points measured by two adjacent laser beams, one above the other, if distance measurement point P8 measured by the upper laser beam is closer to the vehicle body 1 than distance measurement point P7 measured by the lower laser beam, it can be estimated that distance measurement point P8 is an obstacle such as the front work implement 2. When the front work implement 2 is identified based on the relative positions of the distance measurement points in this way, the reflector 28 can be omitted. By applying the algorithm described above, the front work implement 2 can be identified by the controller 30, and the unmeasurable area A' can be reflected in the field of view map.

[0109] In addition, the measurement data of the unmeasurable area A', like the measurement data of the unmeasurable area A, is distinguished from the measurement data of the current topography CL, and is not reflected in the measurement data of the current topography CL in the auxiliary memory device 32b in step S77 (Figure 17).

[0110] Except for the above points, the other configurations and processes by the controller 30 of this embodiment are the same as those of the first embodiment.

[0111] In this embodiment, the same effects as in the first embodiment can be obtained. Furthermore, in this embodiment, the current topography CL can be measured even if the front work implement 2 overlaps within the measurement range of the rangefinder S2. As a result, for example, if the front work implement 2 is clearly outside the area where the topography is to be measured as viewed from the cab 11, the operator can confirm the desired information without having to move the front work implement 2 out of the measurement range of the rangefinder S2 each time.

[0112] <Modification> In the above embodiment, the rangefinder S2 has been described as an example of a type that transmits and receives multiple laser beams to obtain point cloud data of the current topography CL, but it may also be a type that obtains point cloud data by scanning the current topography CL with laser beams. Also, while the rangefinder S2 has been described as an example of a type that uses LiDAR, a stereo camera, millimeter-wave radar, laser radar, an ultrasonic sensor, a monocular camera, etc. can also be used as the rangefinder S2.

[0113] Although the hydraulic excavator is not provided with angle sensors for measuring the angles of the boom, arm, and bucket, or an inclination sensor for measuring the inclination of the vehicle body 1, these sensors may be installed in the hydraulic excavator.

[0114] Figure 4 and other figures show an example of a display in which the measurement range is divided into multiple meshes, but the size of each mesh can be changed as needed within the constraints of the pitch of the point cloud data of the measurement points obtained by the rangefinder S2. The smaller the mesh, the higher the resolution at which the measurement data can be displayed. The aspect ratio of the mesh can also be changed.

[0115] In addition, although Figure 9 and other figures show an example in which the unmeasurable area A is displayed in white, the unmeasurable area A may also be displayed by filling it with a specific color or pattern (black, hatching, etc.). The same applies to the unmeasurable area A' (Figure 20). [Explanation of symbols]

[0116] 1...body, 2...front implement, 11...operator's cab, 15...monitor, 22...boom, 23...arm, 24...bucket, 28...reflector, 30...controller, 32...memory, 42...terrain measurement button, A, A'...unmeasurable area, CL...current terrain, dH...difference from most recent measurement data, dH1...set value, DL...design terrain, IA...slope amount, H...difference between design terrain data and current terrain measurement data, P1-P6...measuring point, S1...position sensor, S2...rangefinder, T...elapsed time, T1...set time, V...vehicle speed, V1...set speed, W...horizontal interval, W1...set interval

Claims

1. a vehicle body having a driver's cab; a front working implement attached to the vehicle body; a monitor provided in the driver's cab; a rangefinder for measuring distances to a plurality of measurement points on the current terrain around the vehicle body; a controller that divides the periphery of the vehicle body into a plurality of meshes and displays the measurement data of the current topography based on the output of the rangefinder on the monitor for each mesh, The controller calculating horizontal coordinates of the plurality of distance measurement points based on the output of the rangefinder; calculating a horizontal distance between each of the plurality of distance measuring points and an adjacent distance measuring point; A hydraulic excavator characterized in that, for areas where the horizontal spacing between adjacent measurement points is less than a set spacing set based on the size of the mesh, height data calculated based on the output of the rangefinder is displayed on the monitor as measurement data of the current terrain for each mesh, and for areas where the horizontal spacing between adjacent measurement points is greater than the set spacing, the meshes where no measurement points exist are displayed on the monitor as unmeasurable areas where measurement is not possible.

2. The hydraulic excavator according to claim 1, a position sensor for acquiring position data of the vehicle body; The controller stores map data of the construction site, The controller based on the vehicle body position data acquired by the position sensor, the coordinate data of the plurality of distance measurement points measured by the rangefinder is associated with the map data; Displaying the map data on the monitor; For areas of the map data displayed on the monitor where the horizontal distance between adjacent ranging points is equal to or less than the set distance, height data calculated based on the output of the rangefinder is superimposed and the measurement data of the current topography is displayed, and for areas of the map data displayed on the monitor where the horizontal distance between adjacent ranging points is greater than the set distance, a display indicating that the area is an unmeasurable area is superimposed. A hydraulic excavator characterized by:

3. The hydraulic excavator according to claim 2, The controller stores design terrain data, The hydraulic excavator is characterized in that the controller displays and outputs a difference between the designed topography data and the measurement data of the current topography on the monitor.

4. The hydraulic excavator according to claim 1, The front working implement is provided with a reflector that can be detected by the range finder, The controller stops measuring the current terrain when the range finder detects the reflector between the current terrain and the range finder. A hydraulic excavator characterized by:

5. The hydraulic excavator according to claim 1, The front working implement is provided with a reflector that can be detected by the range finder, When the rangefinder detects the reflector between the current terrain and the rangefinder, the controller displays on the monitor a message that the front working implement is interfering with the measurement of the current terrain. A hydraulic excavator characterized by:

6. The hydraulic excavator according to claim 4, The hydraulic excavator is characterized in that the reflector is provided at least in one of the tip portion of the arm of the front working machine, the base end portion of the bucket, and the longitudinal intermediate portion of the boom.

7. The hydraulic excavator according to claim 1, a terrain measurement button for instructing measurement of the current terrain by the rangefinder; The controller calculates the measurement data of the current topography using the measurement instruction input by operating the topography measurement button as a trigger, and displays and outputs the data on the monitor. A hydraulic excavator characterized by:

8. The hydraulic excavator according to claim 7, The hydraulic excavator is characterized in that the controller calculates the measurement data of the current topography only when the vehicle speed is less than a set speed.

9. The hydraulic excavator according to claim 7, The controller The measurement data of the current topography is compared with the most recent measurement data of the corresponding coordinates; Updates measurement data only for distance measurement points where the difference from the most recent measurement data is equal to or greater than the set value. A hydraulic excavator characterized by:

10. The hydraulic excavator according to claim 7, The controller The measurement data of the current topography is compared with the most recent measurement data of the corresponding coordinates; Updates the measurement data only for distance measurement points for which the elapsed time from the measurement date and time of the most recent measurement data is equal to or greater than the set time. A hydraulic excavator characterized by:

11. The hydraulic excavator according to claim 2, The controller Calculating the amount of slope of the current topography based on the measurement data of the current topography; The tilt amount is superimposed on the map data and displayed on the monitor. A hydraulic excavator characterized by:

Images