Excavator control system and excavator

Abstract

To improve safety.SOLUTION: A control system for an excavator according to one embodiment of the present disclosure includes: an excavator having a lower traveling body and an upper rotating body mounted revolvable relative to the lower traveling body; a slope recognition device having a configuration for recognizing a slope of the ground on which the excavator is traveling; and a control unit that controls the lower traveling body so as to keep a slope in a traveling direction of the excavator relative to a slope direction of the ground within a predetermined angle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a control system for an excavator and an excavator.

Background Art

[0002] Conventionally, excavators have been used at various work sites. For this reason, excavators often travel on sloping ground (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technique described in Patent Document 1 suppresses tipping and performs a smooth traveling operation by bringing the tip of the front working machine into contact with the ground during uphill travel or downhill travel. However, the technique for suppressing tipping is not limited to the technique described in Patent Document 1, and other methods may be used.

[0005] One aspect of the present invention proposes a technique for improving safety by controlling a lower traveling body.

Means for Solving the Problems

[0006] An excavator control system according to one aspect of the present invention includes an excavator including a lower traveling body and an upper swing body rotatably mounted on the lower traveling body, an inclination recognition device having a configuration for recognizing an inclination of the ground on which the excavator is traveling, and a control unit that controls the lower traveling body so that an inclination of a traveling direction of the excavator with respect to an inclination direction of the ground is within a predetermined angle.

Effects of the Invention

[0007] According to one aspect of the present invention, when the traveling direction of the excavator is inclined with respect to the inclination direction of the ground, safety is improved by controlling the lower traveling body.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Also, the embodiments described below are examples and do not limit the invention, and not all features and combinations thereof described in the embodiments are necessarily essential to the invention. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and the description may be omitted.

[0010] Hereinafter, in the embodiments of the present invention, an example in which an excavator is used as an example of a working machine will be described, but the present invention is not limited to an excavator. It may be applied to construction machines, standard machines, application machines, forestry machines, or transport machines based on hydraulic excavators.

[0011] (First Embodiment) In the first embodiment, a case where an operator remotely operates the excavator 100 will be described.

[0012] FIG. 1 is a schematic diagram showing a configuration example of a remote operation system SYS (an example of a control system of an excavator) of the excavator 100 according to the present embodiment. In the example shown in FIG. 1, the excavator 100 and the remote operation room RC are connected via a communication line NW. Thereby, transmission and reception of information between the excavator 100 and the remote operation room RC can be realized.

[0013] The excavator 100 transmits the detection results from various sensors provided in the excavator 100 to the remote operation room RC using a communication device T1 (see FIG. 3) provided in the excavator 100. For example, the excavator 100 transmits the image information captured by the imaging device S6 (see FIG. 3) to the remote operation room RC.

[0014] In the remote operation system SYS according to the present embodiment, a remote operation room RC is provided. In the remote operation room RC, a display device DR, an operation device R26, an operation sensor R29, an operator's seat DS, a remote controller R30, and a communication device T2 are provided.

[0015] The display device DR is provided for the operator OP in the remote operation room RC to visually recognize the periphery of the excavator 100.

[0016] The operator OP present at the operation seat DS in the remote operation room RC operates the operation device R26. Then, the operation sensor R29 detects the operation content received by the operation device R26. And the remote controller R30 generates an operation signal corresponding to the operation content.

[0017] Then, the communication device T2 transmits the generated operation signal to the excavator 100. By the remote controller R30 transmitting the operation signal, remote operation of the excavator 100 becomes possible.

[0018] The operator OP can grasp the surroundings of the excavator 100 by referring to the image information displayed on the display device DR. However, the image information displayed on the display device DR may be difficult to use to grasp the situation around the excavator 100 compared to actually visually recognizing the surroundings from the excavator 100. For example, it is difficult for the operator OP to grasp the inclination of the ground on which the excavator 100 is traveling or the condition of the crawlers of the excavator 100.

[0019] Therefore, in the remote operation system SYS according to the present embodiment, when there is an inclination on the ground, control for suppressing the tipping over of the excavator 100 due to the inclination is realized.

[0020] <Configuration of the Excavator> First, with reference to FIG. 2, an overview of the excavator 100 according to the present embodiment will be described. FIG. 2 is a side view of the excavator 100 according to the present embodiment.

[0021] The excavator 100 according to the present embodiment includes a lower traveling body 1, an upper slewing body 3 mounted on the lower traveling body 1 so as to be slewing freely via a slewing mechanism 2, a boom 4, an arm 5, and a bucket 6 as an attachment AT, and a cabin 10.

[0022] The lower traveling body 1 (an example of a traveling body) includes, for example, a pair of left and right crawlers, and each crawler is hydraulically driven by traveling hydraulic motors 1ML and 1MR (see FIG. 3) to move the excavator 100.

[0023] The upper slewing body 3 (an example of a slewing body) is driven by a slewing hydraulic motor 2M (see FIG. 3) to slew with respect to the lower traveling body 1.

[0024] The attachment AT (an example of an attachment) includes a boom 4, an arm 5, and a bucket 6.

[0025] The boom 4 is pivotally attached to the front center of the upper slewing body 3 so as to be able to pitch. An arm 5 is pivotally attached to the tip of the boom 4 so as to be able to rotate vertically, and a bucket 6 is pivotally attached to the tip of the arm 5 so as to be able to rotate vertically.

[0026] The bucket 6 is an example of a working tool. The bucket 6 is used, for example, for excavation work or the like. The bucket 6 according to the present embodiment includes a tip 6a and a back surface 6b as parts for forming a horizontal plane.

[0027] Also, other working tools may be attached to the tip of the arm 5 instead of the bucket 6 according to the work content or the like. The other working tools may be, for example, other types of buckets such as a large bucket, a slope bucket, a dredging bucket, etc. Also, the other working tools may be working tools of types other than buckets such as a stirrer, a breaker, a grapple, etc.

[0028] The boom 4, the arm 5, and the bucket 6 are each hydraulically driven by hydraulic cylinders 7, 8, and 9 for the boom, the arm, and the bucket, which serve as hydraulic actuators, with the hydraulic oil discharged from the main pump 14 (see FIG. 3).

[0029] The cab 10 is an operator's cab and is mounted on the front left side of the upper slewing body 3.

[0030] Incidentally, the excavator 100 may be configured such that some of the driven elements such as the lower traveling body 1, the upper revolving body 3, the boom 4, the arm 5, and the bucket 6 are electrically driven. That is, the excavator 100 may be a hybrid excavator, an electric excavator, or the like in which some of the driven elements are driven by electric actuators.

[0031] [Configuration of Excavator] Next, in addition to FIG. 2, with reference to FIG. 3, the specific configuration of the excavator 100 will be described.

[0032] FIG. 3 is a block diagram showing an example of the hardware configuration of the excavator 100 and the remote operation cabin RC according to the present embodiment.

[0033] In FIG. 3, the path through which mechanical power is transmitted is indicated by a double line, the path through which high-pressure hydraulic oil for driving the hydraulic actuator flows is indicated by a solid line, the path through which the pilot pressure is transmitted is indicated by a broken line, and the path through which the electrical signal is transmitted is indicated by a dotted line.

[0034] The excavator 100 includes respective components such as a hydraulic drive system related to the hydraulic drive of the driven elements, an operation system related to the operation of the driven elements, a user interface system related to the information exchange with the user, a communication system related to the communication with the outside, and a control system related to various controls.

[0035] [Hydraulic Drive System] As shown in FIG. 3, the hydraulic drive system of the excavator 100 includes hydraulic actuators HA that hydraulically drive the respective driven elements such as the lower traveling body 1 (left and right crawlers), the upper revolving body 3, the boom 4, the arm 5, and the bucket 6 as described above. Further, the hydraulic drive system of the excavator 100 according to the present embodiment includes an engine 11, a regulator 13, a main pump 14, and a control valve unit 17.

[0036] The hydraulic actuators HA include traveling hydraulic motors 1ML, 1MR, a swing hydraulic motor 2M, a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9.

[0037] Note that part or all of the hydraulic actuator HA of the excavator 100 may be replaced with an electric actuator. That is, the excavator 100 may be a hybrid excavator or an electric excavator.

[0038] The engine 11 is the prime mover of the excavator 100 and the main power source in the hydraulic drive system. The engine 11 is, for example, a diesel engine that uses light oil as fuel. The engine 11 is mounted, for example, at the rear of the upper swing body 3. The engine 11 rotates at a constant speed at a preset target rotational speed under the direct or indirect control of a controller 30 described later, and drives the main pump 14 and the pilot pump 15.

[0039] Note that instead of or in addition to the engine 11, other prime movers (for example, an electric motor) or the like may be mounted on the excavator 100.

[0040] The regulator 13 controls (adjusts) the discharge amount of the main pump 14 under the control of the controller 30. For example, the regulator 13 adjusts the angle of the swash plate (hereinafter, "tilt angle") of the main pump 14 in response to a control command from the controller 30.

[0041] The main pump 14 supplies hydraulic oil to the control valve unit 17 through a high-pressure hydraulic line. The main pump 14 is mounted, for example, at the rear of the upper swing body 3, similar to the engine 11. The main pump 14 is driven by the engine 11 as described above. The main pump 14 is, for example, a variable displacement hydraulic pump. As described above, under the control of the controller 30, the stroke length of the piston is adjusted by adjusting the tilt angle of the swash plate by the regulator 13, and the discharge flow rate and discharge pressure are controlled.

[0042] The control valve unit 17 drives the hydraulic actuator HA according to the operations on the operator's operating device 26, the content of remote operations, or the operation commands corresponding to the automatic driving function. The control valve unit 17 is mounted, for example, at the center of the upper swing body 3. As described above, the control valve unit 17 is connected to the main pump 14 via a high-pressure hydraulic line, and selectively supplies the hydraulic oil supplied from the main pump 14 to the respective hydraulic actuators according to the operations of the operator or the operation commands corresponding to the automatic driving function. The control valve unit 17 includes direction switching valves 17A to 17F that control the flow rate and flow direction of the hydraulic oil supplied from the main pump 14 to each of the hydraulic actuators HA.

[0043] The direction switching valve 17A controls the flow rate and flow direction of the hydraulic oil supplied to the boom cylinder 7. Thereby, the direction switching valve 17A can extend and contract the boom cylinder 7 with variable speed. The direction switching valve 17A is, for example, a spool valve.

[0044] The direction switching valve 17B controls the flow rate and flow direction of the hydraulic oil supplied to the arm cylinder 8. Thereby, the direction switching valve 17B can extend and contract the arm cylinder 8 with variable speed. The direction switching valve 17B is, for example, a spool valve.

[0045] The direction switching valve 17C controls the flow rate and flow direction of the hydraulic oil supplied to the bucket cylinder 9. Thereby, the direction switching valve 17C can extend and contract the bucket cylinder 9 with variable speed. The direction switching valve 17C is, for example, a spool valve.

[0046] The direction switching valve 17D controls the flow rate and flow direction of the hydraulic oil supplied to the travel hydraulic motor 1ML. Thereby, the direction switching valve 17D can rotate the travel hydraulic motor 1ML in both directions with variable speed. The direction switching valve 17D is, for example, a spool valve.

[0047] The direction change valve 17E controls the flow rate and the flowing direction of the hydraulic oil supplied to the travel hydraulic motor 1MR. Thereby, the direction change valve 17E can rotate the travel hydraulic motor 1MR in both directions with variable speed. The direction change valve 17E is, for example, a spool valve.

[0048] The direction change valve 17F controls the flow rate and the flowing direction of the hydraulic oil supplied to the swing hydraulic motor 2M. Thereby, the direction change valve 17F can rotate the swing hydraulic motor 2M in both directions with variable speed. The direction change valve 17F is, for example, a spool valve.

[0049] <Operating system> As shown in FIG. 3, the operating system of the excavator 100 includes a pilot pump 15, an operating device 26, an operation sensor 29, and a proportional valve 31.

[0050] The pilot pump 15 supplies pilot pressure to various hydraulic devices via a pilot line 25. The pilot pump 15 is mounted, for example, at the rear part of the upper swing body 3, similarly to the engine 11. The pilot pump 15 is, for example, a fixed displacement hydraulic pump and is driven by the engine 11 as described above.

[0051] Note that the pilot pump 15 may be omitted. In this case, the hydraulic oil with a relatively low pressure after being decompressed by a predetermined pressure reducing valve from the hydraulic oil with a relatively high pressure discharged from the main pump 14 may be supplied as pilot pressure to various hydraulic devices.

[0052] The operating device 26 is provided near the driver's seat in the cabin 10 and is used for the operator to operate various driven elements. Specifically, the operating device 26 is used for the operator to operate the hydraulic actuator HA that drives each driven element. As a result, the operation of the driven element driven by the hydraulic actuator HA by the operator can be realized. The operating device 26 includes a pedal device and a lever device for operating each driven element (hydraulic actuator HA).

[0053] The operation sensor 29 is configured to detect the operation content of the operator using the operation device 26. In the present embodiment, the operation sensor 29 detects the operation direction and operation amount of the operation device 26 corresponding to each actuator, and outputs an electric signal (hereinafter also referred to as an operation signal) corresponding to the detected value to the controller 30. In the present embodiment, the controller 30 controls the opening area of the proportional valve 31 according to the output of the operation sensor 29. Then, the controller 30 supplies the hydraulic oil discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17. The pressure of the hydraulic oil (pilot pressure) supplied to each pilot port is, in principle, a pressure corresponding to the operation direction and operation amount of the operation device 26 corresponding to each hydraulic actuator. In this way, the operation device 26 is configured to be able to supply the hydraulic oil discharged by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve unit 17. Thereby, the hydraulic actuator HA can be driven.

[0054] Also, the direction switching valves 17A to 17F for driving the respective hydraulic actuators HA built in the control valve unit 17 may be electromagnetic solenoid type. In this case, the operation signal output from the operation device 26 may be directly input to the control valve unit 17 (that is, to the electromagnetic solenoid type direction switching valve).

[0055] Note that the operating device 26 may be a hydraulic pilot type. Specifically, the operating device 26 utilizes the hydraulic oil supplied from the pilot pump 15 through the pilot line and outputs a pilot pressure corresponding to the operation content to the secondary pilot line. And the secondary pilot line is connected to the control valve unit 17. Thereby, a pilot pressure corresponding to the operation content regarding various driven elements (hydraulic actuator HA) in the operating device 26 can be input to the control valve unit 17. Therefore, the control valve unit 17 can drive each hydraulic actuator HA according to the operation content of the operating device 26 by an operator or the like. In this case, an operation state sensor capable of acquiring information regarding the operation state of the operating device 26 is provided, and the output of the operation state sensor is taken into the controller 30. Thereby, the controller 30 can grasp the operation state of the operating device 26. The operation state sensor is, for example, a pressure sensor that acquires information regarding the pilot pressure (operation pressure) of the secondary pilot line of the operating device 26.

[0056] Also, as described above, some or all of the hydraulic actuators HA may be replaced with electric actuators. In this case, for example, the controller 30 may output an operation command corresponding to the operation content of the operating device 26 or the content of the remote operation defined by the remote operation signal to the electric actuator or a driver that drives the electric actuator. Further, the electric actuator may be configured to be operable by the operating device 26 when an operation signal is input from the operating device 26 to the electric actuator or the driver or the like.

[0057] Also, when the excavator 100 is solely remotely operated or solely operates by the fully automatic operation function, the operating device 26 may be omitted.

[0058] The proportional valve 31 functions as a control valve for machine control and is provided for each driven element (hydraulic actuator HA) to be operated by the operating device 26 and for each operating direction (e.g., the raising and lowering directions of the boom 4) of the driven element (hydraulic actuator HA). For example, two proportional valves 31 are provided for each double-acting hydraulic actuator HA for driving the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, the bucket 6, etc. The proportional valve 31 is provided, for example, in a pilot line between the pilot pump 15 and the control valve unit 17, and may be configured to be able to change its flow passage area (i.e., the cross-sectional area through which the hydraulic oil can flow). Thereby, the proportional valve 31 can output a predetermined pilot pressure to the secondary pilot line by using the hydraulic oil of the pilot pump 15 supplied through the primary pilot line. Therefore, the proportional valve 31 can apply a predetermined pilot pressure according to an operation command from the controller 30 to the control valve unit 17. Thus, for example, the controller 30 can directly supply a pilot pressure corresponding to the operation content (operation signal) of the operating device 26 from the proportional valve 31 to the control valve unit 17, and realize the operation of the excavator 100 based on the operation of the operator.

[0059] Further, the controller 30 may control the proportional valve 31 to realize the automatic operation function of the excavator 100. Specifically, the controller 30 outputs an operation command corresponding to the automatic operation function to the proportional valve 31 from the proportional valve 31. Thereby, the controller 30 can realize the operation of the excavator 100 by the automatic operation function.

[0060] Further, the controller 30 controls the proportional valve 31 to realize the remote operation of the excavator 100. Specifically, the controller 30 outputs an operation command corresponding to the content of the operation specified by the operation signal received from the remote operation room RC to the proportional valve 31 by the communication device T1. Thereby, the controller 30 can supply a pilot pressure corresponding to the content of the remote operation from the proportional valve 31 to the control valve unit 17, and realize the operation of the excavator 100 based on the remote operation of the operator.

[0061] In addition, when the operating device 26 is a hydraulic pilot type, a shuttle valve may be provided in the pilot line between the operating device 26 and the proportional valve 31 and the control valve unit 17. The shuttle valve has two inlet ports and one outlet port, and outputs the hydraulic oil having the higher pilot pressure among the pilot pressures input to the two inlet ports to the outlet port. The shuttle valve is provided for each driven element (hydraulic actuator HA) to be operated by the operating device 26 and for each operating direction of the driven element (hydraulic actuator HA), similar to the proportional valve 31. For example, two shuttle valves are provided for each double-acting hydraulic actuator HA for driving the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, the bucket 6, and the like. One of the two inlet ports of the shuttle valve is connected to the secondary pilot line of the operating device 26 (specifically, the above-described lever device or pedal device included in the operating device 26), and the other is connected to the secondary pilot line of the proportional valve 31. The outlet port of the shuttle valve is connected to the pilot port of the corresponding direction switching valve of the control valve unit 17 through the pilot line. The corresponding direction switching valve is the direction switching valve that drives the hydraulic actuator HA that is the operation target of the above-described lever device or pedal device connected to one inlet port of the shuttle valve. Therefore, each of these shuttle valves can apply the higher one of the pilot pressure in the secondary pilot line of the operating device 26 and the pilot pressure in the secondary pilot line of the proportional valve 31 to the pilot port of the corresponding direction switching valve. That is, the controller 30 can control the corresponding direction switching valve without depending on the operation of the operator on the operating device 26 by outputting a pilot pressure higher than the pilot pressure in the secondary side of the operating device 26 from the proportional valve 31. Therefore, the controller 30 can control the operation of the driven elements (lower traveling body 1, upper slewing body 3, boom 4, arm 5, bucket 6) regardless of the operation state of the operator on the operating device 26, and realize the automatic operation function and the remote operation function.

[0062] Also, when the operating device 26 is a hydraulic pilot type, in addition to the shuttle valve, a pressure reducing valve may be provided in the pilot line between the operating device 26 and the shuttle valve. The pressure reducing valve operates, for example, in response to a control signal input from the controller 30 and is configured to be able to change its flow passage area. Thereby, when the operating device 26 is being operated by the operator, the controller 30 can forcibly reduce the pilot pressure output from the operating device 26. Therefore, even when the operating device 26 is being operated, the controller 30 can forcibly suppress or stop the operation of the hydraulic actuator HA corresponding to the operation of the operating device 26. Further, the controller 30 can, for example, even when the operating device 26 is being operated, reduce the pilot pressure output from the operating device 26 with the pressure reducing valve to be lower than the pilot pressure output from the proportional valve 31. Therefore, by controlling the proportional valve 31 and the pressure reducing valve, the controller 30 can surely act a desired pilot pressure on the pilot port of the direction switching valve in the control valve unit 17, for example, regardless of the operation content of the operating device 26. Thus, the controller 30 can more appropriately realize the automatic operation function and the remote operation function of the excavator 100, for example, by controlling the pressure reducing valve in addition to the proportional valve 31.

[0063] <User interface system> As shown in FIG. 3, the user interface system of the excavator 100 includes an operating device 26, an operation sensor 29, an output device D1, and an input device D2.

[0064] The output device D1 outputs various information to the user of the excavator 100 (for example, the operator in the cab 10) or the people around the excavator 100 (for example, workers or drivers of work vehicles).

[0065] For example, the output device D1 includes lighting equipment, display devices, etc., which output various types of information in a visual manner. The lighting equipment is, for example, a warning light (indicator lamp), etc. The display device is, for example, a liquid crystal display, an organic EL (Electroluminescence) display, etc. For example, the lighting equipment and the display device may be provided inside the cabin 10 and output various types of information to the operator inside the cabin 10 and the like in a visual manner. Also, the lighting equipment and the display device may be provided on the side surface of the upper swing body 3 or the like and output various types of information to the workers around the excavator 100 and the like in a visual manner.

[0066] In addition, the output device D1 may include a sound output device that outputs various types of information in an auditory manner. The sound output device includes, for example, a buzzer, a speaker, etc. The sound output device is provided, for example, on at least one of the inside and outside of the cabin 10 and outputs various types of information to the operator inside the cabin 10 and the people (workers, etc.) around the excavator 100 in an auditory manner.

[0067] Also, the output device D1 may include a device that outputs various types of information in a tactile manner such as vibration of the driver's seat.

[0068] The input device D2 receives various inputs from the user (for example, the operator) of the excavator 100, and the signal corresponding to the received input is taken into the controller 30. For example, as shown in FIG. 2, the input device D2 is provided inside the cabin 10 and receives inputs from the operator inside the cabin 10 and the like. Also, the input device D2 may be provided, for example, on the side surface of the upper swing body 3 or the like and receive inputs from the workers around the excavator 100 and the like.

[0069] For example, the input device D2 includes an operation input device that receives inputs by mechanical operations from the user. The operation input device may include a touch panel mounted on the display device, a touch pad installed around the display device, a button switch, a lever, a toggle, a knob switch provided on the operation device 26 (lever device), etc.

[0070] Further, the input device D2 may include a voice input device that receives a user's voice input. The voice input device includes, for example, a microphone.

[0071] Further, the input device D2 may include a gesture input device that receives a user's gesture input. The gesture input device includes, for example, an imaging device that captures the state of the gesture performed by the user.

[0072] Further, the input device D2 may include a biological input device that receives a user's biological input. The biological input includes, for example, the input of biological information such as the user's fingerprint and iris.

[0073] <Communication system> As shown in FIG. 3, the communication system of the excavator 100 according to the present embodiment includes a communication device T1.

[0074] The communication device T1 is connected to an external communication line NW and communicates with a device provided separately from the excavator 100. The device provided separately from the excavator 100 may include, in addition to the device outside the excavator 100, a portable terminal device (portable terminal) brought into the cab 10 by the user of the excavator 100. The communication device T1 may include, for example, a mobile communication module compliant with standards such as 4G (4th Generation) and 5G (5th Generation). Further, the communication device T1 may include, for example, a satellite communication module. Further, the communication device T1 may include, for example, a Wi-Fi communication module or a Bluetooth (registered trademark) communication module. Further, when there are a plurality of connectable communication lines NW, the communication device T1 may include a plurality of communication devices T1 according to the type of the communication line NW.

[0075] For example, the communication device T1 communicates with an external device such as a remote operation room RC in the work site through a local communication line constructed at the work site. The local communication line is, for example, a mobile communication line using local 5G (so-called local 5G) constructed at the work site or a local network using WiFi6.

[0076] Further, the communication device T1 is configured to transmit and receive information to and from a communication device T2 installed in the remote operation room RC through a wide-area communication line including the work site, that is, a wide-area network.

[0077] <Control system> As shown in FIG. 3, the control system of the excavator 100 includes a controller 30. The controller 30 performs various controls related to the excavator 100.

[0078] The functions of the controller 30 may be realized by any hardware, or any combination of hardware and software, etc. For example, as shown in FIG. 3, the controller 30 includes an auxiliary storage device 30A, a memory device 30B, a CPU (Central Processing Unit) 30C, and an interface device 30D connected by a bus B1.

[0079] The auxiliary storage device 30A is a non-volatile storage means, stores the installed programs, and stores necessary files, data, etc. The auxiliary storage device 30A is, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a flash memory, or the like.

[0080] The memory device 30B, for example, loads the program in the auxiliary storage device 30A so that the CPU 30C can read it when there is a program start instruction. The memory device 30B is, for example, an SRAM (Static Random Access Memory).

[0081] The CPU 30C, for example, executes the program loaded in the memory device 30B and realizes various functions of the controller 30 according to the instructions of the program.

[0082] The interface device 30D functions as a communication interface for connecting to a communication line inside, for example, the excavator 100. The interface device 30D may include a plurality of different types of communication interfaces according to the type of the communication line to be connected.

[0083] Also, the interface device 30D functions as an external interface for reading data from a recording medium and writing data to the recording medium. The recording medium is, for example, a dedicated tool connected by a cable detachable from a connector installed inside the cab 10. Also, the recording medium may be a general-purpose recording medium such as an SD memory card or a USB (Universal Serial Bus) memory. Thereby, a program for realizing various functions of the controller 30 can be provided by, for example, a portable recording medium and installed in the auxiliary storage device 30A of the controller 30. Also, the program may be downloaded from another computer outside the excavator 100 through the communication device T1 and installed in the auxiliary storage device 30A.

[0084] Note that a part of the functions of the controller 30 may be realized by another controller (control device). That is, the functions of the controller 30 may be distributed and realized by a plurality of controllers mounted on the excavator 100.

[0085] The boom angle sensor S1 is attached to the boom 4 and detects the pitching angle of the boom 4 with respect to the upper swing body 3 (hereinafter referred to as the "boom angle"). For example, in a side view, it detects the angle formed by the straight line connecting the fulcrums at both ends of the boom 4 with respect to the turning plane of the upper swing body 3. The boom angle sensor S1 may include, for example, a rotary encoder, an acceleration sensor, a 6-axis sensor, an IMU (Inertial Measurement Unit), etc. Further, the boom angle sensor S1 may include a potentiometer using a variable resistor, a cylinder stroke sensor that detects the stroke amount of a hydraulic cylinder (boom cylinder 7) corresponding to the boom angle, etc. Hereinafter, the same applies to the arm angle sensor S2, the bucket angle sensor S3, and the machine body inclination sensor S4. The detection signal corresponding to the boom angle by the boom angle sensor S1 is taken into the controller 30.

[0086] The arm angle sensor S2 is attached to the arm 5 and detects the rotation angle of the arm 5 with respect to the boom 4 (hereinafter referred to as the "arm angle"). For example, in a side view, it detects the angle formed by the straight line connecting the fulcrums at both ends of the arm 5 with respect to the straight line connecting the fulcrums at both ends of the boom 4. The detection signal corresponding to the arm angle by the arm angle sensor S2 is taken into the controller 30.

[0087] The bucket angle sensor S3 is attached to the bucket 6 and detects the rotation angle of the bucket 6 with respect to the arm 5 (hereinafter referred to as the "bucket angle"). For example, in a side view, it detects the angle formed by the straight line connecting the fulcrum and the tip (cutting edge) of the bucket 6 with respect to the straight line connecting the fulcrums at both ends of the arm 5. The detection signal corresponding to the bucket angle by the bucket angle sensor S3 is taken into the controller 30.

[0088] In this embodiment, the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3 are also referred to as the angle sensors of the attachment AT. And the detection result by the angle sensor of the attachment AT is also referred to as the angle of the attachment AT. The angle of the attachment AT indicates, for example, the boom angle, the arm angle, and the bucket angle.

[0089] The body tilt sensor S4 detects the tilt state of the body (the upper slewing body 3 or the lower traveling body 1) with respect to the horizontal plane. The body tilt sensor S4 is attached to, for example, the upper slewing body 3 and detects the tilt angles (hereinafter, "front-back tilt angle" and "left-right tilt angle") around two axes in the front-back direction and the left-right direction of the excavator 100 (i.e., the upper slewing body 3). The detection signals corresponding to the tilt angles (front-back tilt angle and left-right tilt angle) by the body tilt sensor S4 are taken into the controller 30.

[0090] The slewing angle sensor S5 outputs detection information regarding the slewing state of the upper slewing body 3. The slewing angle sensor S5 detects, for example, the slewing angular velocity and the slewing angle of the upper slewing body 3. The slewing angle sensor S5 includes, for example, a gyro sensor, a resolver, a rotary encoder, and the like.

[0091] In this embodiment, an example using the slewing angle sensor S5 will be described, but this embodiment is not limited to the method using the slewing angle sensor S5. For example, an IMU (Inertial Measurement Unit) sensor may be used instead of the slewing angle sensor S5.

[0092] For example, the controller 30 can grasp (estimate) the position of the tip (bucket 6) of the attachment AT based on the outputs of the sensors S1 to S5. Therefore, the controller 30 can control the operation by the automatic operation function of the excavator 100 while grasping the position of the tip of the attachment AT.

[0093] Note that when the sensor S4 includes a gyro sensor, a 6-axis sensor, an IMU, etc. that can detect the angular velocity around three axes, the slewing state (e.g., the slewing angular velocity) of the upper slewing body 3 may be detected based on the detection signal of the sensor S4. In this case, the sensor S5 may be omitted.

[0094] The imaging device S6 images the surroundings of the excavator 100. The imaging device S6 includes a camera S6F that images the front of the excavator 100, a camera S6L that images the left side of the excavator 100, a camera S6R that images the right side of the excavator 100, and a camera S6B that images the rear of the excavator 100.

[0095] The camera S6F is attached, for example, to the ceiling of the cab 10, that is, inside the cab 10. Also, the camera S6F may be attached outside the cab 10, such as to the roof of the cab 10 or the side surface of the boom 4. The camera S6L is attached to the left end of the upper revolving body 3, the camera S6R is attached to the right end of the upper revolving body 3, and the camera S6B is attached to the rear end of the upper revolving body 3.

[0096] The imaging device S6 (cameras S6F, S6B, S6L, S6R) is, for example, a single-eye wide-angle camera having a very wide angle of view. Also, the imaging device S6 may be able to acquire data regarding distance (depth) in addition to two-dimensional images, such as a stereo camera, a TOF (Time Of Flight) camera, etc. (hereinafter collectively referred to as "3D camera"). The captured image by the imaging device S6 is captured by the controller 30.

[0097] Also, when the operator OP in the remote operation room RC receives the captured image from the communication device T1 of the excavator 100, the operator can remotely operate the excavator 100 while confirming the operation of the attachment AT including the bucket 6 by visually recognizing the surrounding image based on the camera S6F through the display device DR.

[0098] Alternatively, instead of or in addition to the imaging device S6, a distance sensor may be provided on the upper swing body 3. The distance sensor is attached, for example, to the upper part of the upper swing body 3 and acquires data regarding the distance and direction of surrounding objects with respect to the excavator 100. Further, the distance sensor may acquire (generate) three-dimensional data (for example, data of coordinate information of a point cloud) of surrounding objects of the excavator 100 within the sensing range based on the acquired data. The distance sensor is, for example, LiDAR (Light Detection and Ranging). Also, for example, the distance sensor may be a millimeter-wave radar, an ultrasonic sensor, an infrared sensor, or the like.

[0099] The positioning device PS is configured to acquire information regarding the position of the excavator 100. In the present embodiment, the positioning device PS is configured to measure the position and orientation of the excavator 100. For example, the positioning device PS is a GNSS (Global Navigation Satellite System) receiver incorporating an electronic compass, and measures the latitude, longitude, and altitude of the current position of the excavator 100 and also measures the orientation of the excavator 100.

[0100] The excavator 100 operates an actuator (for example, a hydraulic actuator) according to the operation of an operator boarding the cab 10, and drives operating elements (hereinafter, "driven elements") such as the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, and the bucket 6.

[0101] Alternatively, instead of being configured to be operable by an operator in the cab 10, or in addition thereto, the excavator 100 may be configured to be remotely operable from outside the excavator 100. When the excavator 100 is remotely operated, the inside of the cab 10 may be unmanned.

[0102] Further, the excavator 100 may automatically operate the actuator regardless of the content of the operator's operation. Thereby, the excavator 100 realizes a function of automatically operating at least a part of the driven elements such as the lower traveling body 1, the upper swing body 3, the boom 4, the arm 5, and the bucket 6, that is, a so-called "automatic operation function" or "machine control function".

[0103] The automatic operation function may include a function of automatically operating driven elements (actuators) other than the driven element (actuator) of the operation target in response to an operation on the operator's operation device 26 or a remote operation, that is, a so-called "semiautomatic operation function" or "operation support type machine control function". Further, the automatic operation function may include a function of automatically operating at least a part of a plurality of driven elements (hydraulic actuators) on the premise that there is no operation on the operator's operation device 26 or a remote operation, that is, a so-called "fully automatic operation function" or "fully automatic type machine control function". In the excavator 100, when the fully automatic operation function is valid, the inside of the cab 10 may be unmanned. Further, the semiautomatic operation function, the fully automatic operation function, etc. may include a mode in which the operation content of the driven element (actuator) of the automatic operation target is automatically determined according to a rule defined in advance. Further, the semiautomatic operation function, the fully automatic operation function, etc. may include a mode (so-called "automatic operation function") in which the excavator 100 autonomously makes various determinations and the operation content of the driven element (hydraulic actuator) of the automatic operation target is determined autonomously according to the determination result.

[0104] Specifically, when the operator operates the arm 5 through the operating device 26, the controller 30 may automatically operate at least one of the boom 4 and the bucket 6 so that a predefined target design surface (hereinafter simply referred to as the "design surface") coincides with the tip position of the bucket 6. Further, the controller 30 may also automatically operate the arm 5 regardless of the operating state of the operating device 26 that operates the arm 5. That is, the controller 30 may trigger the operation of the operating device 26 by the operator and cause the attachment to perform a predefined operation. Hereinafter, the function of the controller 30 that operates at least one of the boom 4 and the bucket 6 in addition to the arm 5 according to the operation of the operating device 26 corresponding to the arm 5 is referred to as the "semiautomatic operation function". The semiautomatic operation function may be executed, for example, by operating a predetermined switch (hereinafter referred to as the "MC (Machine Control) switch") disposed at the tip of any one of the lever devices included in the operating device 26.

[0105] <Block Configuration of Remote Operation System> FIG. 4 is a functional block diagram showing a configuration example of the remote operation system SYS according to the present embodiment. In the example shown in FIG. 4, the block configurations of each of the remote operation room RC and the excavator 100 included in the remote operation system SYS are shown.

[0106] As shown in FIG. 4, the remote operation room RC is provided with an operation sensor R29, a remote controller R30, a display device DR, and a communication device T2.

[0107] The display device DR according to the present embodiment may be a multi-display composed of a plurality of monitors or may be composed of a single large-screen monitor.

[0108] The communication device T2 is connected to an external communication line NW and communicates with the excavator 100. The communication device T2 may include, for example, a mobile communication module compliant with standards such as 4G (4th Generation) or 5G (5th Generation). Further, the communication device T2 may include, for example, a satellite communication module. Also, the communication device T2 may include, for example, a Wi-Fi communication module, a Bluetooth (registered trademark) communication module, or the like. Further, when there are a plurality of connectable communication lines NW, the communication device T2 may include a plurality of communication devices T2 according to the type of the communication line NW.

[0109] The operation sensor R29 is configured to detect the operation content of the operator OP using the operation device R26. In the present embodiment, the operation sensor 29 detects the operation direction and operation amount of the operation device 26 corresponding to each actuator of the excavator 100, and outputs an electrical signal (hereinafter also referred to as an operation signal) corresponding to the detected value to the remote controller R30.

[0110] Next, the functions of the remote controller R30 installed in the remote operation room RC will be described. The remote controller R30 is configured to remotely operate the excavator 100. The remote controller R30 includes, as functional blocks, a display control unit 351, an operation signal generation unit 352, and a communication control unit 353.

[0111] The communication control unit 353 controls the transmission and reception of information between the communication device T2 and the communication device T1 of the excavator 100. For example, the communication control unit 353 receives the detection results of various sensors S1 to S5 of the excavator 100, the position information by the positioning device PS, and the captured image by the imaging device S6 from the communication device T1 of the excavator 100.

[0112] The display control unit 351 performs control for displaying information on the display device DR. For example, the display control unit 351 performs control to display the received imaging information on the display device DR. Further, the display control unit 351 may perform control to display information based on the detection results of various sensors S1 to S5 or the position information obtained by the positioning device PS on the display device DR.

[0113] The operation signal generation unit 352 is configured to generate an operation signal. In the present embodiment, the operation signal generation unit 352 is configured to generate an operation signal based on the output of the operation sensor R29.

[0114] The communication control unit 353 transmits the generated operation signal to the communication device T1.

[0115] As shown in FIG. 4, the excavator 100 includes a positioning device PS, an imaging device S6, a swing angle sensor S5, a machine body inclination sensor S4, an operation sensor 29, a proportional valve 31, a controller 30, and a communication device T1.

[0116] The controller 30 stores a map information storage unit 30A1 in the auxiliary storage device 30A.

[0117] The map information storage unit 30A1 stores map information for the excavator 100 to travel. The map information stores the shape (three-dimensional shape) of the work site where the excavator 100 can move. For example, the inclination angle and the like are included in the three-dimensional shape of the map information.

[0118] The map information may be, for example, position information in a world coordinate system based on GNSS (Global Navigation Satellite System). In the present embodiment, the latitude and longitude are indicated by the x-axis and y-axis, and the altitude is indicated by the z-axis.

[0119] The functions of the controller 30 mounted on the excavator 100 will be described. As shown in FIG. 5, the controller 30 includes, as functional blocks, a communication control unit 301, an acquisition unit 302, an inclination angle calculation unit 303, a target traveling direction specifying unit 304, a determination unit 305, a correction unit 306, and an actuator drive unit 307.

[0120] FIG. 5 is an explanatory diagram showing the control of the lower traveling body 1 of the excavator 100 by the controller 30 according to the present embodiment. In FIG. 5, an example is shown in which a conventional excavator 100A and the excavator 100 according to the present embodiment are traveling downhill on a sloped ground 500 with an inclination angle θ. Conventionally, when an excavator travels on a sloped ground, it is considered preferable to travel straight ahead with respect to the sloping direction.

[0121] Therefore, as shown by the traveling trajectories 513 and 514, the conventional excavator 100A is an example of traveling straight ahead with respect to the sloping direction. Similarly, the excavator 100 according to the present embodiment is also an example of traveling straight ahead with respect to the sloping direction, as shown by the traveling trajectories 511 and 512.

[0122] In the example shown in FIG. 5, the sloped ground 500 has a slippery ground such as mud 501. A situation where both the excavators 100A and 100 move on the mud 501 also occurs.

[0123] Then, in the conventional excavator 100A, a sudden change in the traveling direction may occur due to the crawler slipping on the mud 501. The sudden change in the traveling direction may deviate from the intended traveling route of the conventional excavator 100A and may also cause the excavator 100A to tip over.

[0124] Therefore, the controller 30 of the excavator 100 according to the present embodiment controls the lower traveling body 1 so that a sudden change in the traveling direction does not occur even when the crawler slips on the mud 501. In other words, the traveling direction is maintained substantially parallel to the sloping direction.

[0125] In particular, in the remote operation system SYS of the excavator 100 according to the present embodiment, when the operator OP operates the excavator 100 from the remote operation cab RC, it is difficult to recognize the inclination of the road surface on which the excavator 100 is traveling. In addition, there is a delay until the detection results of various sensors of the excavator 100 are displayed on the display device DR. Therefore, by the controller 30 performing the control on the lower traveling body 1 as described above, the possibility of the excavator 100 tipping over can be reduced.

[0126] Returning to FIG. 4, the communication control unit 301 controls the transmission and reception of information with the communication device T2 in the remote operation cab RC using the communication device T1. For example, the communication control unit 301 receives an operation signal from the communication device T2 in the remote operation cab RC.

[0127] The acquisition unit 302 acquires detection results from various sensors provided on the excavator 100. For example, the acquisition unit 302 acquires information from a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a body inclination sensor S4, a swing angle sensor S5, an imaging device S6, a positioning device PS, and the like.

[0128] The communication control unit 301 transmits the detection results of various sensors S1 to S5 of the excavator 100, the position information by the positioning device PS, and the captured image by the imaging device S6 to the communication device T2 using the communication device T1.

[0129] The inclination angle calculation unit 303 calculates the inclination of the traveling direction of the excavator 100 with respect to the inclination direction of the ground based on the inclination state of the upper swing body 3 detected by the body inclination sensor S4 and the swing angle detected by the swing angle sensor S5.

[0130] Specifically, the acquisition unit 302 acquires the pitch angle and roll angle of the upper swing body 3 as the inclination state of the upper swing body 3 detected by the body inclination sensor S4, and acquires the swing angle from the swing angle sensor S5. Then, the inclination angle calculation unit 303 calculates the pitch angle and roll angle of the lower traveling body 1 from the pitch angle and roll angle of the upper swing body 3 and the swing angle.

[0131] In this embodiment, it is considered that the roll angle of the lower traveling body 1 corresponds to the inclination of the traveling direction of the excavator 100 with respect to the inclination direction of the ground. For example, when the roll angle of the lower traveling body 1 is approximately "0" degrees, the controller 30 can recognize that the traveling direction of the excavator 100 with respect to the inclination direction is substantially parallel. In other words, there is no inclination in the traveling direction with respect to the inclination direction. When the absolute value of the roll angle increases from approximately "0" degrees, the controller 30 can recognize that an inclination has occurred in the traveling direction with respect to the inclination direction. Note that this embodiment does not limit the method of recognizing the inclination of the traveling direction of the excavator 100 by the roll angle of the lower traveling body 1, and other methods may be used.

[0132] The inclination angle calculation unit 303 calculates the inclination angle of the ground on which the lower traveling body 1 is traveling based on the pitch angle and roll angle of the lower traveling body 1. The method of calculating the inclination angle of the ground is omitted from the description as a well-known method may be used.

[0133] Therefore, the configuration combining the body inclination sensor S4 and the turning angle sensor S5 functions as an inclination recognition device for recognizing the inclination of the ground on which the excavator 100 is traveling, and is configured to be able to calculate the inclination of the traveling direction with respect to the inclination direction. In this embodiment, by using the combined configuration of the body inclination sensor S4 and the turning angle sensor S5, the controller 30 can immediately recognize a change in the pitch angle or roll angle of the lower traveling body 1. Therefore, the controller 30 can immediately perform control based on the change, and thus can improve safety.

[0134] Note that in this embodiment, an example of using the body inclination sensor S4 as a configuration for detecting the pitch angle and roll angle of the upper slewing body 3 is described. However, the method of using the body inclination sensor S4 as a configuration for detecting the pitch angle and roll angle of the upper slewing body 3 is not limited. For example, a positioning device PS configured as a GNSS receiver capable of detecting the inclination of the excavator 100 may be used.

[0135] When the ground inclination is recognized based on the captured image by the imaging device S6, the target traveling direction specifying unit 304 specifies the traveling direction (hereinafter referred to as the target traveling direction) that the excavator 100 aims at.

[0136] That is, as an example of the inclination recognition device for recognizing the ground inclination, the imaging device S6 is used. Note that, in this embodiment, an example using the imaging device S6 is described, but the method is not limited to using the imaging device S6. That is, any spatial recognition device that can recognize the space of the excavator 100 may be used, for example, LiDAR or the like may be used.

[0137] Specifically, the target traveling direction specifying unit 304 specifies a region where the ground inclination angle changes around the excavator 100 from the captured image by the imaging device S6, and in the specified region, specifies the target traveling direction for making it substantially parallel to the inclination direction.

[0138] The method by which the target traveling direction specifying unit 304 recognizes the ground inclination shown in the image information from the image information is omitted from the description assuming that a well-known method is used.

[0139] By using the imaging device S6, the controller 30 according to this embodiment can recognize in advance the inclination of the traveling destination of the excavator 100. Specifically, the controller 30 can recognize the inclination angle of the ground (hereinafter also referred to as the inclined plane) having an inclination existing at the traveling destination of the excavator while traveling on a plane with a gentler inclination angle than the horizontal plane or the inclined plane until the start of traveling. In this way, the controller 30 can recognize the inclination angle of the inclined plane even before recognizing the inclination angle of the inclined plane with the body inclination sensor S4. That is, the controller 30 can specify the traveling direction on the inclined plane and the like before the excavator 100 reaches the inclined plane. Since the controller 30 can easily respond to the change of the inclined plane, improvement in safety can be realized.

[0140] Specifically, the target traveling direction specifying unit 304 calculates the difference in the relative inclination angle between the current ground and the ground after the inclination angle has switched from the current ground based on the captured image. Since the controller 30 of the excavator 100 recognizes the inclination state of the current ground, it recognizes the inclination state of the ground after the inclination angle has switched from the difference in the relative inclination angle. Then, based on the inclination state, the controller 30 can specify the target traveling direction for straight-ahead traveling with respect to the inclination direction on the ground after the inclination angle has switched.

[0141] Note that this embodiment does not limit the method for calculating the difference in the relative inclination angle to calculations based on the captured image. For example, the target traveling direction specifying unit 304 may specify the inclination angle of the ground at the destination of the excavator 100 from the map information stored in the map information storage unit 30A1 and the position information of the excavator 100.

[0142] The determination unit 305 determines whether or not the conditions for controlling the lower traveling body 1 are satisfied. For example, the determination unit 305 determines whether or not the inclination angle of the ground calculated by the inclination angle calculation unit 303 is equal to or greater than a first reference angle (an example of a predetermined threshold value). The first reference angle may be set to, for example, 20 degrees. Note that the first reference angle is not limited to 20 degrees, and may be set to an angle at which the excavator 100 may tip over or the like, and may be set according to the implementation modes such as the speed and shape of the excavator 100.

[0143] When the determination unit 305 determines that the inclination angle of the ground calculated by the inclination angle calculation unit 303 is equal to or greater than the first reference angle, the determination unit 305 further determines whether or not the roll angle has become equal to or greater than a predetermined reference roll angle. The predetermined reference roll angle according to this embodiment is defined as an angle determined as a reference for determining that the traveling direction with respect to the inclination direction is not substantially parallel. For example, the predetermined reference roll angle is defined as an angle obtained by adding a predetermined margin to the roll angle of "0" degrees.

[0144] Based on the determination result of the determination unit 305, the correction unit 306 corrects the operation signal received by the communication control unit 301 or the operation signal acquired by the acquisition unit 302.

[0145] When the determination unit 305 determines that the inclination angle of the ground calculated by the inclination angle calculation unit 303 is equal to or greater than a first reference angle (an example of a predetermined threshold), the correction unit 306 corrects the operation signal in order to cause the lower traveling body 1 to perform control to make the traveling direction of the excavator 100 substantially parallel to the inclination direction. In addition, in this embodiment, an example of performing control to make the traveling direction of the excavator 100 substantially parallel to the inclination direction will be described, but the control is not limited to making the traveling direction and the inclination direction substantially parallel. The correction unit 306 may perform control so that the angle between the traveling direction and the inclination direction of the excavator 100 becomes smaller. The angle between the traveling direction and the inclination direction after control may be a predetermined angle that can suppress the tipping over of the excavator 100 or the like. That is, even when the correction unit 306 corrects the operation signal so that the angle between the traveling direction and the inclination direction of the excavator 100 becomes smaller, the possibility of the excavator 100 tipping over or the like can be reduced, so that an improvement in safety can be realized.

[0146] Specifically, when the determination unit 305 determines that the inclination angle of the ground is equal to or greater than a first reference angle (an example of a predetermined threshold) and the roll angle of the lower traveling body 1 is equal to or greater than a predetermined reference roll angle, the correction unit 306 adjusts the traveling speed of one or more of the right crawler and the left crawler and corrects the operation signal so as to make the roll angle substantially "0" degrees. When the roll angle of the lower traveling body 1 becomes substantially "0" degrees, the lateral inclination of the excavator 100 is suppressed, so it can be considered that the traveling direction and the inclination direction of the excavator 100 are substantially parallel.

[0147] When the excavator 100 is traveling on an inclined surface and there is an inclination in the lateral direction of the excavator 100, the correction unit 306 corrects the operation signal to perform correction to adjust the traveling speed of the right crawler and the traveling speed of the left crawler so as to suppress the lateral inclination of the excavator 100.

[0148] For example, when the lower traveling body 1 is shifted to the right, the correction unit 306 corrects the operation signal to reduce the operation amount of the left operation lever that controls the traveling speed of the left crawler so as to lower the traveling speed of the left crawler. Further, when the lower traveling body 1 is shifted to the right, the correction unit 306 may correct the operation signal to increase the operation amount of the right operation lever so as to increase the traveling speed of the right crawler.

[0149] As another example, when the lower traveling body 1 is shifted to the left, the correction unit 306 corrects the operation signal to reduce the operation amount of the right operation lever that controls the traveling speed of the right crawler so as to lower the traveling speed of the right crawler. When the lower traveling body 1 is shifted to the left, the correction unit 306 may correct the operation signal to increase the operation amount of the left operation lever so as to increase the traveling speed of the left crawler.

[0150] Further, when the inclination angle of the ground calculated by the inclination angle calculation unit 303 is smaller than the first reference angle (an example of a predetermined threshold value), the determination unit 305 suppresses the correction of the operation signal for making the traveling direction of the excavator 100 substantially parallel to the inclination direction, and suppresses the control of the lower traveling body 1. In this way, when the inclination of the ground is gentle or substantially horizontal, it is assumed that the excavator 100 does not tip over, and the correction of the operation signal is suppressed. Therefore, when the inclination of the ground is gentle, the controller 30 suppresses the correction of the operation signal, and the excavator 100 can move according to the operation by the operator OP, so that both the safety and the operability of the excavator 100 can be improved.

[0151] When the communication control unit 301 determines that the ground inclination angle is equal to or greater than a first reference angle (an example of a predetermined threshold value) and the roll angle of the lower traveling body 1 is equal to or greater than a predetermined reference roll angle, it transmits, via the communication device T1, a signal indicating a warning to correct the traveling direction of the excavator 100 according to the inclination direction to the remote operation room RC. Then, the remote controller R30 in the remote operation room RC outputs a warning to the operator OP to correct the traveling direction according to the received signal. The warning may be in the form of sound or a display on the display device DR. Thereby, the operator OP can recognize that the traveling direction is corrected according to the inclined surface.

[0152] In this embodiment, the case where the correction unit 306 automatically corrects the operation signal according to the determination result of the determination unit 305 has been described. However, this embodiment does not limit the method of automatically correcting the operation signal, and the operation signal may be corrected according to the determination result of the operator OP.

[0153] For example, when the determination unit 305 determines that the ground inclination angle is equal to or greater than a first reference angle (an example of a predetermined threshold value) and the roll angle of the lower traveling body 1 is equal to or greater than a predetermined reference roll angle, the communication control unit 301 transmits a signal requesting permission for correction to the remote operation room RC.

[0154] When the remote controller R30 in the remote operation room RC receives the signal, it outputs an inquiry as to whether the traveling direction may be changed according to the ground inclination angle by voice or on the screen. Then, when the remote controller R30 receives an operation from the operator OP via the operation sensor R29 indicating that the operation direction may be changed, it transmits a signal indicating permission for correction to the excavator 100. Then, the correction unit 306 corrects the operation signal according to the received signal.

[0155] The actuator drive unit 307 is configured to drive the actuators mounted on the excavator 100. In the present embodiment, the actuator drive unit 307 generates and outputs an operation signal for each of a plurality of solenoid valves included in the proportional valve 31 based on an operation signal transmitted from the remote controller R30.

[0156] When the operation signal is corrected by the correction unit 306, the actuator drive unit 307 generates and outputs an operation signal for controlling the lower traveling body 1 from the corrected operation signal.

[0157] Next, the processing procedure executed by the controller 30 according to the present embodiment will be described. FIG. 6 is a flowchart showing a processing procedure for the excavator 100 to travel on a sloping ground by the controller 30 according to the present embodiment.

[0158] First, the communication control unit 301 receives an operation signal from the remote operation room RC (S1601). The present embodiment is not limited to the mode of receiving the operation signal from the remote operation room RC. For example, the acquisition unit 302 may acquire an operation signal based on the operation amount detected by the operation sensor 29.

[0159] The inclination angle calculation unit 303 calculates the roll angle and pitch angle of the lower traveling body 1 as the inclination state of the lower traveling body 1 (S1602).

[0160] Furthermore, the inclination angle calculation unit 303 calculates the inclination angle of the ground on which the excavator 100 is traveling based on the roll angle and pitch angle of the lower traveling body 1 (S1603).

[0161] The determination unit 305 determines whether or not the calculated inclination angle is equal to or greater than a first reference angle (an example of a predetermined threshold value) (S1604). When it is determined that the calculated inclination angle is smaller than the first reference angle (S1604: NO), the controller 30 ends the process assuming that the ground is not inclined and normal control may be performed.

[0162] On the other hand, when the determination unit 305 determines that the calculated inclination angle is equal to or greater than the first reference angle (an example of a predetermined threshold) (S1604: YES), it determines whether the traveling direction of the excavator 100 is inclined with respect to the inclination direction based on the roll angle (S1605). When it is determined that the traveling direction is not inclined (S1605: NO), the process proceeds to the process of S1607.

[0163] On the other hand, when the determination unit 305 determines that the traveling direction of the excavator 100 is inclined with respect to the inclination direction (S1605: YES), the communication control unit 301 transmits a signal indicating a warning to correct the traveling direction to the remote operation room RC via the communication device T1 (S1606).

[0164] Thereafter, the correction unit 306 corrects the operation signal so that the lower traveling body 1 performs control to make the traveling direction of the excavator 100 substantially parallel to the inclination direction (S1607). In the flowchart shown in FIG. 6, an example of automatically correcting the operation signal is described. However, as described above, it may be switched whether to correct the operation signal according to the operation of the operator OP in the remote operation room RC.

[0165] Then, the actuator drive unit 307 generates and outputs an operation signal for controlling the lower traveling body 1 from the operation signal (S1608).

[0166] Thereafter, the communication control unit 301 receives an operation signal from the remote operation room RC (S1609).

[0167] The inclination angle calculation unit 303 calculates the roll angle and pitch angle of the lower traveling body 1 as the inclination state of the lower traveling body 1 (S1610).

[0168] Furthermore, the inclination angle calculation unit 303 calculates the inclination angle of the ground on which the excavator 100 is traveling based on the roll angle and pitch angle of the lower traveling body 1 (S1611).

[0169] The determination unit 305 determines whether the calculated inclination angle is less than or equal to the second reference angle (S1612). If it is determined that the angle is not less than or equal to the second reference angle, that is, the angle is greater than the second reference angle (S1612: NO), the process is performed again from S1605. The second reference angle is an angle smaller than the first reference angle, for example, 10 degrees.

[0170] On the other hand, when the determination unit 305 determines that the calculated inclination angle is less than or equal to the second reference angle (S1612: NO), the process ends.

[0171] In addition, in this embodiment, an example has been described in which when it is determined that the traveling direction is inclined, the lower traveling body 1 is controlled to make the traveling direction of the excavator 100 substantially parallel to the inclination direction. However, the control method is not limited to this. For example, the controller 30 may perform control to correct the operation signal on the condition that the angle of the traveling direction of the excavator 100 with respect to the inclination direction exceeds a predetermined angle.

[0172] FIG. 7 is an explanatory diagram showing the traveling locus of the crawler when the controller 30 according to this embodiment controls the lower traveling body 1. In the example shown in FIG. 7, as shown in the traveling loci 1701 and 1702, it is assumed that the excavator 100 is traveling straight with respect to the inclined surface 1700.

[0173] Then, it is assumed that at the point 1703, the left crawler slips and the excavator 100 shifts to the right. When the control shown in FIG. 6 is not performed, the excavator travels as shown by the traveling loci 1711 and 1712.

[0174] On the other hand, the controller 30 according to the present embodiment performs the control shown in FIG. 6. Specifically, when the controller 30 recognizes that the traveling direction is inclined with respect to the inclination direction while the shovel 100 is traveling on the ground, the controller 30 corrects the operation signal so that the traveling direction is substantially parallel to the inclination direction (so as to suppress the inclination). Therefore, since the shovel 100 can continue traveling as shown by the traveling trajectories 1701 and 1702, improvement in safety can be realized.

[0175] The present embodiment is not limited to the method of correcting the operation signal when it is recognized that the current traveling direction is inclined with respect to the inclination direction. When it is recognized that the traveling direction is about to incline with respect to the inclination direction while traveling on a substantially horizontal plane, the operation signal may be corrected in advance.

[0176] Next, the processing procedure executed by the controller 30 according to the present embodiment will be described. FIG. 8 is a flowchart showing the processing procedure for the shovel 100 to travel before the inclination of the ground is switched by the controller 30 according to the present embodiment. First, it is assumed that the shovel 100 is traveling on a substantially horizontal ground.

[0177] First, the communication control unit 301 receives an operation signal from the remote operation room RC (S1801). The present embodiment is not limited to the mode of receiving the operation signal from the remote operation room RC. For example, the acquisition unit 302 may acquire an operation signal based on the operation amount detected by the operation sensor 29.

[0178] The target traveling direction specifying unit 304 determines whether there is a region where the inclination angle of the ground changes in the ground shape around the shovel 100 from the captured image by the imaging device S6 (S1802). When it is determined that there is no region where the inclination angle of the ground changes (to be equal to or greater than the first reference angle) (S1802: NO), the controller 30 ends the process assuming that the ground is not inclined and thus normal control may be performed.

[0179] On the other hand, when the target traveling direction specifying unit 304 determines that there is a region where the inclination angle of the ground changes, based on the captured image by the imaging device S6, it specifies the target yaw angle of the excavator 100 that becomes the target traveling direction for making it substantially parallel to the inclination direction on the ground after the inclination angle changes (S1803). The target yaw angle is defined as the rotation angle of the lower traveling body 1 for traveling substantially parallel to the inclination direction.

[0180] After that, the determination unit 305 determines, based on the captured image by the imaging device S6, that it has reached a predetermined distance (for example, 1 m) before the region where the inclination angle changes (S1804). Note that in this embodiment, an example of correcting the operation signal 1 m before the inclination angle changes is described, but it is not limited to 1 m before. A shorter distance than 1 m or a longer distance than 1 m may be used. Furthermore, the operation signal may be corrected at the stage when it is recognized that there is a region where the inclination angle of the ground changes.

[0181] Then, the determination unit 305 determines whether the current traveling direction of the excavator 100 is inclined with respect to the target traveling direction specified in S1803, in other words, whether the target yaw angle of the excavator 100 is different from "0" degrees (S1805). If it is determined that the current traveling direction is not inclined with respect to the target traveling direction, in other words, the target yaw angle is substantially the same as "0" degrees (S1805: NO), the process proceeds to the process of S1808. Note that this embodiment is not limited to the method of making the traveling direction coincide with the target yaw angle. For example, control may be performed such that the traveling direction is included within a predetermined range (for example, ±5 degrees) based on the target yaw angle.

[0182] On the other hand, when the determination unit 305 determines that the current traveling direction of the excavator 100 is inclined with respect to the target traveling direction specified in S1803, in other words, the target yaw angle of the excavator 100 is different from "0" degrees (S1805: YES), the communication control unit 301 transmits a signal indicating a warning to correct the traveling direction to the remote operation room RC via the communication device T1 (S1806).

[0183] After that, the correction unit 306 corrects the operation signal so that the traveling direction of the excavator 100 becomes the target traveling direction. In other words, the correction unit 306 corrects the operation signal so that the traveling direction of the excavator 100 becomes the direction indicated by the target yaw angle (S1807). In this embodiment, an example in which the operation signal is corrected so as to travel according to the target traveling direction before the inclination angle is switched will be described, but the correction method is not limited thereto, and the operation signal may be corrected so as to travel according to the target traveling direction at the timing when the inclination angle is switched or after the inclination angle is switched.

[0184] Then, the actuator drive unit 307 generates and outputs an operation signal for controlling the lower traveling body 1 from the operation signal, and ends the process (S1808).

[0185] Note that in this embodiment, an example in which control is performed to cause the lower traveling body 1 to perform control to make the traveling direction of the excavator 100 and the inclination direction substantially parallel when it is determined that the traveling direction is inclined from the target traveling direction has been described, but the control method is not limited thereto. For example, the controller 30 may perform control to correct the operation signal on the condition that the angle of the traveling direction of the excavator 100 with respect to the target traveling direction exceeds a predetermined angle.

[0186] FIG. 9 is an explanatory diagram showing the traveling locus of the crawler when the controller 30 according to this embodiment controls the lower traveling body 1. FIG. 9 shows an example in which the ground changes from a substantially horizontal ground 1900A to a ground 1900B inclined at a first reference angle or more.

[0187] Then, the target traveling direction specifying unit 304 of the controller 30 specifies the ground shape based on the captured image of the imaging device S6 of the excavator 100. That is, the target traveling direction specifying unit 304 specifies the ground 1900A and the ground 1900B, and then specifies the region 1905 where the ground 1900A and the ground 1900B are switched.

[0188] On the ground 1900A, the excavator 100 is traveling according to the traveling directions indicated by the traveling trajectories 1901 and 1902. And if the excavator 100 proceeds without changing the traveling direction, on the ground 1900B, it will proceed as indicated by the traveling trajectories 1911 and 1912. In this case, since the traveling direction of the excavator 100 is inclined compared to the inclination direction, there is a possibility that the excavator 100 may tip over.

[0189] Therefore, the controller 30 according to the present embodiment performs the control shown in FIG. 8. That is, before the excavator 100 reaches the region 1905, in other words, before switching from the ground 1900A to the ground 1900B, the controller 30 corrects the operation signal so that the traveling direction becomes substantially parallel to the inclination direction of the ground 1900B. As a result, the traveling direction of the excavator 100 switches to the traveling directions indicated by the traveling trajectories 1903 and 1904. Therefore, since the excavator 100 can travel in a traveling direction substantially parallel to the inclination direction, the possibility of tipping over can be reduced and the safety can be improved.

[0190] The example in which the controller 30 according to the present embodiment corrects the received operation signal so that the traveling direction becomes substantially parallel to the inclination direction has been described. However, the present embodiment is not limited to the example of correcting the received operation direction. For example, the controller 30 may generate an operation signal such that the traveling direction becomes substantially parallel to the inclination direction. As a modification, when the traveling direction of the excavator 100 is considerably inclined compared to the inclination direction, the controller 30 may apply a method of generating an operation signal for correcting the inclination instead of correcting the operation signal.

[0191] In the present embodiment, the determination unit 305 has been described as an example of controlling the lower traveling body 1 when the inclination angle of the ground calculated by the inclination angle calculation unit 303 is equal to or greater than the first reference angle (an example of a predetermined threshold). However, the present embodiment is not limited to the example of controlling the lower traveling body 1 only when the inclination angle of the ground is equal to or greater than the first reference angle (an example of a predetermined threshold). For example, the control of the lower traveling body 1 described above may always be performed.

[0192] In addition, in this embodiment, an example of controlling the lower traveling body 1 to make the traveling direction and the inclination direction of the excavator 100 substantially parallel has been described. However, this embodiment does not limit the control of the lower traveling body 1 to making the traveling direction and the inclination direction of the excavator 100 substantially parallel. Instead, control may be performed to make the inclination of the traveling direction of the excavator 100 with respect to the inclination direction of the ground within a predetermined angle. The predetermined angle may be determined according to embodiments such as the shape and speed of the excavator 100 as an angle at which tipping of the excavator 100 can be suppressed. For example, the predetermined angle may be set to 5 degrees.

[0193] In this embodiment, an example in which the controller 30 corrects the operation signal to control the lower traveling body 1 has been described. However, this embodiment does not limit the method by which the controller 30 corrects the operation signal. For example, the remote controller R30 may correct the operation signal.

[0194] When remotely operating the excavator 100 as in this embodiment, it is difficult for the operator OP to grasp the situation around the excavator 100 or the direction of the crawler of the excavator 100 only based on the information displayed on the display device DR. In addition, there is a delay until the content detected by the excavator 100 is displayed on the display device DR. For this reason, it is difficult for the operator OP to recognize slippage or the like of the excavator 100 or to respond to slippage or the like. On the other hand, the controller 30 according to this embodiment can improve safety by automatically controlling the lower traveling body 1 of the excavator 100 by performing the above-described control.

[0195] (Modification Example 1 of the First Embodiment) In the above-described embodiment, an example of correcting the traveling direction so as to follow the target traveling direction when the inclination angle of the ground changes has been described. However, the above-described embodiment does not necessarily perform such correction. For example, even when the inclination angle of the ground changes, the traveling direction of the excavator 100 may be maintained. Then, the controller 30 controls the lower traveling body 1 to travel along a path extending in the traveling direction.

[0196] Then, when the controller 30 deviates from the path extending in the traveling direction or when the changes in the pitch angle and roll angle of the lower traveling body 1 occur abruptly, the controller 30 corrects the operation signal on the assumption that the excavator 100 has slipped so as to proceed along the path. By this control, even when the excavator 100 slips, the traveling direction is maintained, so that the overturning of the excavator 100 can be suppressed.

[0197] (Modification Example 2 of the First Embodiment) The above-described embodiment has described an example in which the combined configuration of the body inclination sensor S4 and the swing angle sensor S5 functions as an inclination recognition device for recognizing the inclination of the ground on which the excavator 100 is traveling. However, the above-described embodiment does not limit the inclination recognition device for recognizing the inclination of the ground to the combined configuration of the body inclination sensor S4 and the swing angle sensor S5.

[0198] Therefore, in Modification Example 2 of the first embodiment, an example is given in which a configuration combining a map information storage unit 30A1 that stores map information of the world coordinate system indicating the inclination of the ground and a positioning device PS that acquires the position information of the excavator 100 in the world coordinate system is used as the inclination recognition device.

[0199] The inclination angle calculation unit 303 according to this modification example refers to the map information and derives the inclination angle and inclination direction of the ground corresponding to the position indicated by the position information. Further, the inclination angle calculation unit 303 calculates the traveling direction of the excavator 100 from the change in the position of the excavator 100 with the passage of time indicated by a plurality of pieces of position information, and calculates the pitch angle and roll angle of the lower traveling body 1 from the traveling direction, the inclination angle of the ground, and the inclination direction.

[0200] Regarding other processes, the description is omitted as being the same as in the above-described embodiment. In this modification example, by performing the above-described control, the possibility of the excavator 100 overturning can be reduced in the same manner as in the above-described embodiment, so that an improvement in safety can be realized.

[0201] (Second Embodiment) In the above-described embodiment, an example in which the operator OP operates the excavator 100 from the remote operation room RC has been described. However, the above-described embodiment is not limited to the method in which the operator OP operates the excavator 100 from the remote operation room RC. As a second embodiment, a case where the operator riding in the cabin 10 operates the excavator 100 will be described.

[0202] In the present embodiment, the operator operates the excavator 100 using the operating device 26. Then, the acquisition unit 302 acquires, from the operation sensor 29, an operation signal indicating the operation content of the operating device 26 detected by the operation sensor 29.

[0203] Regarding the subsequent processing, the description will be omitted as the same as in the above-described embodiment. In the present embodiment, even when the operator operates from the cabin 10, the same effects as those in the above-described embodiment can be obtained.

[0204] (Third Embodiment) In the above-described embodiment, an example in which the operator operates the excavator 100 has been described. However, the above-described embodiment is not limited to the case where the operator operates. As a third embodiment, a case where the controller 30 performs autonomous control of the excavator 100 will be described.

[0205] The controller 30 according to the present embodiment realizes the machine control function by reading a program stored in the auxiliary storage device 30A.

[0206] For example, the controller 30 performs control of the attachment AT, turning control of the upper swing body 3, and traveling control of the lower traveling body 1 according to the construction data stored in the auxiliary storage device 30A.

[0207] For example, the controller 30 generates a path along which the lower traveling body 1 travels, and performs traveling control of the lower traveling body 1 along the path.

[0208] For example, when there is an inclined surface on the way to the destination, the controller 30 generates a route so as to be substantially parallel to the inclination direction of the inclined surface. Then, the controller 30 generates an operation signal for moving along the route. Then, the actuator drive unit 307 generates and outputs an operation signal for controlling the lower traveling body 1 from the operation signal.

[0209] Furthermore, when the controller 30 determines that the inclination angle of the ground is equal to or greater than the first reference angle and the roll angle is equal to or greater than the first reference angle, the controller 30 corrects the operation signal so as to cause the lower traveling body 1 to perform control to make the traveling direction of the excavator 100 substantially parallel to the inclination direction. The specific correction method is the same as that of the first embodiment, and the description thereof is omitted. In the present embodiment, even when performing autonomous control, the same effects as those of the above-described embodiments can be obtained.

[0210] <Function> In the above-described embodiments and modifications, by performing the above-described control, the controller 30 makes the inclination of the traveling direction of the excavator 100 with respect to the inclination direction of the ground within a predetermined angle. For example, in order to make the traveling direction substantially parallel to the inclination direction, by controlling the lower traveling body 1, it is possible to suppress the tipping over of the excavator 100 and realize an improvement in safety.

[0211] As described above, the control system for an excavator and the embodiments of the excavator according to the present invention have been described. However, the present invention is not limited to the above-described embodiments. Within the scope described in the claims, various changes, modifications, substitutions, additions, deletions, and combinations are possible. Naturally, they also belong to the technical scope of the present invention.

Explanation of Reference Numerals

[0212] 100 Excavator 1 Lower traveling body 2 Slewing mechanism 3 Upper slewing body 4 Boom 5 Arm 6 Bucket S1 Boom angle sensor S2 Arm Angle Sensor S3 Bucket Angle Sensor S4 Airframe Inclination Sensor S5 Turning Angle Sensor S6 Imaging Device PS Positioning Device T1 Communication Device 30 Controller 301 Communication Control Unit 302 Acquisition Unit 303 Inclination Angle Calculation Unit 304 Target Travel Direction Specifying Unit 305 Judgment Unit 306 Correction Unit 307 Actuator Drive Unit RC Remote Operation Room R30 Remote Controller 351 Display Control Unit 352 Operation Signal Generation Unit 353 Communication Control Unit T2 Communication Device

Claims

1. An excavator comprising a lower traveling body and an upper slewing body that is rotatably mounted on the lower traveling body, an inclination recognition device having a configuration for recognizing the inclination of the ground on which the excavator is traveling, and a control unit that controls the lower traveling body so that the inclination of the traveling direction of the excavator with respect to the inclination direction of the ground is within a predetermined angle. A control system for an excavator comprising the above.

2. The control unit controls the lower traveling body in order to make the inclination direction of the ground and the traveling direction substantially parallel. The excavator control system according to Claim 1.

3. When the inclination angle of the ground is lower than a predetermined threshold value, the control unit suppresses the control of the lower traveling body to bring it within the predetermined angle. The excavator control system according to Claim 1.

4. When the ground switches from a substantially horizontal plane to a plane having a predetermined inclination angle, the control unit controls the lower traveling body so that the traveling direction with respect to the inclination direction of the ground having the predetermined inclination angle is within the predetermined angle. The excavator control system according to Claim 1.

5. While the excavator is traveling on the ground, when the control unit recognizes that the inclination of the traveling direction with respect to the inclination direction has become equal to or greater than the predetermined angle based on the information acquired by the inclination recognition device, the control unit is configured to control the lower traveling body so that it is within the predetermined angle. The excavator control system according to Claim 1.

6. The inclination recognition device includes a slewing angle sensor that detects the slewing angle of the upper slewing body and a machine inclination sensor that detects the inclination state of the upper slewing body. The control unit calculates the inclination of the traveling direction of the excavator with respect to the inclination direction of the ground based on the inclination state of the upper slewing body and the slewing angle. The excavator control system according to Claim 1.

7. The inclination recognition device includes a storage medium that stores map information in a predetermined coordinate system representing the inclination of the ground, and a positioning device that acquires the position information of the excavator in the predetermined coordinate system. The control unit recognizes the inclination angle of the ground on which the lower traveling body is located and the traveling direction of the excavator based on the map information and the position information. The excavator control system according to Claim 1.

8. The inclination recognition device includes a space recognition device that detects the surroundings of the excavator. The control unit recognizes a change in the inclination of the ground on which the excavator is traveling from the detection result of the space recognition device. The control system for an excavator according to claim 1.

9. A lower traveling body, An upper slewing body that is rotatably mounted on the lower traveling body, An inclination recognition device having a configuration for recognizing that the ground on which the excavator is traveling is inclined, A control unit that controls the lower traveling body so that the inclination of the traveling direction of the excavator with respect to the inclination direction of the ground is within a predetermined angle. An excavator comprising:

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