Operating machinery

Abstract

In a working machine equipped with a front working device, the working machine is equipped with: a state quantity detection device that detects a state quantity related to the operating state of the working device; and a control device that controls the operation of the working machine based on an operation signal sent from a remote device via wireless communication, and the control device evaluates the communication status of the wireless communication, and when limiting the operation of the working machine based on the evaluation result, the restriction on the operation of the working machine is relaxed based on the detection result of the state quantity detection device. In this way, it is possible to suppress the deterioration of the workability and appropriately limit the operation based on the communication status.

Description

Technical Field

[0001] The invention relates to a working machine. Background Art

[0002] As a technology related to remote operation of a working machine, for example, Patent Document 1 discloses a working vehicle comprising: a photographing device that photographs an image on which a working object is projected; an image sending unit that sends the image photographed by the photographing device to a control device; an operation signal receiving unit that receives an operation signal from the control device; and an action control unit that limits the operation signal according to the transmission status of the image.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-068346 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the above-mentioned prior art, for example, when the communication delay time suddenly increases, the operating signal of the working machine is limited according to the communication status, and the working machine is stopped urgently. Therefore, for example, when the bucket is filled with sand and soil, the sand and soil as the cargo may be scattered in the case of an emergency stop. In addition, depending on the working posture, the stability of the vehicle body may be significantly reduced due to the emergency stop. That is, in the above-mentioned prior art, there is a concern about the scattering of the cargo due to the emergency stop and the deterioration of the workability due to the reduction of the stability of the working machine.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a working machine capable of suppressing deterioration in workability and appropriately limiting operation according to communication conditions.

[0009] Means for solving problems

[0010] The present application includes multiple means for solving the above-mentioned problems. To give one example, in a working machine with a front working device, the working machine includes: a state quantity detection device, which detects a state quantity related to the operating state of the working device; and a control device, which controls the operation of the working machine based on an operation signal sent from a remote device via wireless communication, and the control device evaluates the communication status of the wireless communication, and when restricting the operation of the working machine based on the evaluation result, the restriction on the operation of the working machine is alleviated based on the detection result of the state quantity detection device.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to appropriately limit the operation according to the communication status while suppressing the deterioration of the workability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The diagram schematically shows the appearance of a remote control device and a hydraulic excavator as an example of a working machine.

[0014] Figure 2 This diagram shows an extracted hydraulic circuit system, a controller (control device), and other peripheral structures of a hydraulic excavator.

[0015] Figure 3 This is a diagram showing the details of the electromagnetic valve unit, and is a diagram showing the structures of the boom cylinder, the arm cylinder, and the bucket cylinder extracted from the diagram.

[0016] Figure 4 This is a diagram showing the details of the electromagnetic valve unit, and is a diagram showing the structures of the travel hydraulic motor and the swing hydraulic motor in an extracted manner.

[0017] Figure 5 It is the hardware structure diagram of the controller.

[0018] Figure 6 This is a functional block diagram showing the processing functions of the controller.

[0019] Figure 7 This is a side view illustrating the coordinate system of the excavator.

[0020] Figure 8 This is a top view illustrating the coordinate system of the excavator.

[0021] Fig. 9 1 is a flowchart showing a slow deceleration determination process performed by a slow deceleration determination unit.

[0022] Fig.10 : is a flowchart showing the target actuator speed calculation and correction processing of the target motion calculation unit.

[0023] Fig.11 It is a diagram showing the relationship between the operation signal and the actuator target speed.

[0024] Fig.12 This is a graph showing the relationship between the communication delay time and the deceleration coefficient.

[0025] Fig.13 This is a diagram showing an example of how the communication delay time changes over time.

[0026] Fig.14 This is a diagram showing an example of how the deceleration coefficient K changes with the passage of time.

[0027] Fig.15This is a diagram showing an example of how the actuator target speed changes over time.

[0028] Fig.16 This is a diagram showing an example of a table defining the relationship between the communication delay time and the deceleration coefficient. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described using the drawings. In the following description, a hydraulic excavator equipped with a front working device is described as an example of a working machine, but the present invention can also be applied to working machines other than the hydraulic excavator.

[0030] In the following description, when there are a plurality of identical components, a letter may be added to the end of the reference numeral (number), but the letter may be omitted and the plurality of components may be collectively described. That is, for example, when there are two hydraulic pumps 2a and 2b, they may be collectively described as pump 2.

[0031] <First embodiment>

[0032] Reference Figure 1 to Figure 15 A first embodiment of the present invention will be described.

[0033] <Basic structure>

[0034] Figure 1 2 is a diagram schematically showing the appearance of a remote control device and a hydraulic excavator as an example of a working machine according to the present embodiment. Figure 2 This diagram shows an extracted hydraulic circuit system, a controller (control device), and other peripheral structures of a hydraulic excavator.

[0035] exist Figure 1 In the embodiment, the hydraulic excavator 100 is composed of a multi-jointed front working device 1A and a vehicle body 1B. The vehicle body 1B of the hydraulic excavator 100 is composed of a lower traveling body 11 that is driven by left and right traveling hydraulic motors 3a and 3b, and an upper rotating body 12 that is mounted on the lower traveling body 11 and rotated by a rotating hydraulic motor 4. Figure 1 Only the left hydraulic motor 3b is shown in the figure, and the right hydraulic motor 3a is only shown in the figure. Figure 2 Medium picture.

[0036] The front working device 1A is constructed by connecting a plurality of driven parts (a boom 8, an arm 9, and a bucket 10) that rotate in the vertical direction. The base end of the boom 8 is supported rotatably via a boom pin at the front of the upper rotating body 12. The arm 9 is rotatably connected to the front end of the boom 8 via an arm pin, and the bucket 10 is rotatably connected to the front end of the arm 9 via a bucket pin. The boom 8 is driven by a boom cylinder 5, the arm 9 is driven by an arm cylinder 6, and the bucket 10 is driven by a bucket cylinder 7. In the following description, the boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 are sometimes collectively referred to as hydraulic cylinders 5 to 7 or hydraulic actuators 5 to 7.

[0037] Here, the hydraulic excavator coordinate system set in the hydraulic excavator will be described. Figure 7 and Figure 8 This is a diagram that explains the coordinate system of the excavator. Figure 7 represents a side view, Figure 8 Indicates a top view.

[0038] like Figure 7 and Figure 8 As shown, in this embodiment, an excavator coordinate system (local coordinate system) is defined for the hydraulic excavator 100. The excavator coordinate system is an XYZ coordinate system fixed to the lower traveling body 11, and a vehicle body coordinate system is set, which has: a Z axis, which passes through the rotation center point in the direction along the rotation center axis of the upper rotating body 12 and takes the upper direction as positive; an X axis, which passes through the base end of the boom perpendicularly to the Z axis in the direction along the plane in which the front working device 1A operates and takes the front direction as positive when the upper rotating body 12 faces the front relative to the lower traveling body 11; and a Y axis, which passes through the intersection of the Z axis and the X axis and is set in a manner to become a right-handed coordinate system. Figure 7 The direction toward the front of the paper is positive.

[0039] In addition, the distance from the intersection of the X-axis and the Z-axis (origin O) to the base end of the boom is defined as L0, the length of the boom 8 (the straight-line distance between the connecting parts at both ends) is defined as L1, the length of the arm 9 (the straight-line distance between the connecting parts at both ends) is defined as L2, the length of the bucket 10 (the straight-line distance between the connecting part of the arm and the blade tip) is defined as L3, the angle between the boom 8 and the XY plane (the relative angle between the straight line in the length direction and the XY plane) is defined as a rotation angle α, the angle between the arm 9 and the boom 8 (the relative angle between the straight line in the length direction) is defined as a rotation angle β, the angle between the bucket 10 and the arm 9 (the relative angle between the straight line in the length direction) is defined as a rotation angle γ, the angle between the lower traveling body 11 and the upper rotating body 12 (the relative angle between the center line of the front device 1A and the X-axis when the XY plane is viewed from above the Z axis, refer to Figure 8) is defined as the rotation angle θ. Therefore, the coordinates of the bucket blade tip position and the posture of the front working device 1A in the excavator coordinate system can be expressed by L0, L1, L2, L3, α, β, γ, and θ.

[0040] Furthermore, the inclination of the vehicle body 1B of the hydraulic excavator 100 in the front-rear direction with respect to the horizontal plane is defined as an angle θ.

[0041] Back to Figure 1 In the front working device 1A, as a posture detection device for measuring the rotation angles α, β, and γ of the boom 8, the arm 9, and the bucket 10, a boom angle sensor 30 is installed on the boom pin, an arm angle sensor 31 is installed on the arm pin, and a bucket angle sensor 32 is installed on the bucket link 13. In addition, in the present embodiment, as the angle sensors 30, 31, and 32, angle sensors that detect the relative angles in the connection parts of the plurality of driven components 8, 9, and 10 are exemplified, but are not limited to this. For example, an inertial measurement unit (IMU: Inertial Measurement Unit) that can detect the relative angles of each of the plurality of driven components 8, 9, and 10 with respect to a reference plane (for example, a horizontal plane) can be substituted.

[0042] The upper rotating body 12 is provided with a sensor for detecting the inclination angle of the upper rotating body 12 (the vehicle body 1B of the hydraulic excavator 100) relative to a reference plane (for example, a horizontal plane). The vehicle body inclination angle sensor 33. The vehicle body inclination angle sensor 33 can use, for example, a liquid-sealed electrostatic capacitance type inclination angle sensor, an inertial measurement device, or the like.

[0043] A rotation angle sensor 34 for detecting a relative angle θ between the upper rotating body 12 and the lower traveling body 11 is mounted on the rotation center axis of the upper rotating body 12 relative to the lower traveling body 11 .

[0044] The angle sensors 30 , 31 , 32 , the vehicle body inclination angle sensor 33 , and the rotation angle sensor 34 constitute a posture detection device.

[0045] like Figure 1 and Figure 2As shown, in the cab provided in the upper rotating body 12, there are provided: an operating device 23a for operating the right travel hydraulic motor 3a of the lower travel body 11; an operating device 23b for operating the left travel hydraulic motor 3b of the lower travel body 11; an operating device 1a for operating the boom cylinder 5 for driving the boom 8 and the bucket cylinder 7 for driving the bucket 10; an operating device 1b for operating the arm cylinder 6 of the arm 9 and the rotating hydraulic motor 4 of the upper rotating body 12; and an engine speed setting device 480 for setting the speed of the engine 18 (described later) which is the prime mover mounted on the hydraulic excavator 100. The engine speed setting device 480 is, for example, an engine control dial for setting the engine speed according to the rotation operation of the operator. Hereinafter, the right travel lever 23a, the left travel lever 23b, the operating right lever 1a, and the operating left lever 1b are sometimes collectively referred to as the operating devices 1 and 23.

[0046] In addition, if Figure 1 As shown, a remote control device 800 for remotely controlling the hydraulic excavator 100 is provided in, for example, a field office or the like. The remote control device 800 is provided with the same structure as that in the cab of the hydraulic excavator 100, and includes: operating devices 801a, 801b, 823a, 823b that generate operating signals corresponding to the operating devices 1 and 23 of the hydraulic excavator 100; an engine speed setting device 880 that is equivalent to the engine speed setting device 480 of the hydraulic excavator 100; and a display device 810 that presents an image of the working position of the front working device 1A of the hydraulic excavator 100 to the operator operating the remote control device 800. The display device 810 is one or more monitors, screens (including projectors), etc., and presents an image corresponding to the viewpoint of the operator when sitting in the cab of the hydraulic excavator 100 to the operator operating the remote control device 800, for example, by displaying an image captured by a camera (not shown) provided at the upper front portion of the cab of the hydraulic excavator 100.

[0047] The operation signals output from the operation devices 801 and 823 and the signal output from the engine speed setting device 880 are transmitted via the communication device 850 of the remote control device 800 and the communication device 650 of the hydraulic excavator 100 (see below). Figure 5 and Figure 6 ) is transmitted to the controller 40 of the hydraulic excavator 100.

[0048] The hydraulic excavator 100 includes a remote ride selection device 670 (see below) for switching the operating state of the hydraulic excavator 100 between a ride operation state and a remote operation state. Figure 5), when the riding operation state is selected, the hydraulic excavator 100 operates based on signals from the operating devices 1, 23, and when the remote operation state is selected, the hydraulic excavator 100 operates based on signals from the operating devices 801, 823 of the remote control device 800.

[0049] like Figure 2 As shown in the figure, the engine 18, which is a prime mover mounted on the upper rotating body 12, drives the hydraulic pumps 2a, 2b and the pilot pump 48. The hydraulic pumps 2a, 2b are variable displacement pumps whose capacities are controlled by the regulators 2aa, 2ba, and the pilot pump 48 is a fixed displacement pump. The hydraulic pump 2a and the pilot pump 48 draw hydraulic oil from the hydraulic oil tank. Although the detailed structure of the regulators 2aa, 2ba is omitted, the control signals output from the controller 40 are input to the regulators 2aa, 2ba, and the discharge flow rates of the hydraulic pumps 2a, 2b are controlled according to the control signals.

[0050] The operating devices 1 and 23 are electric rod type, and generate electric signals corresponding to the amount and direction of operation of the operator and send them to the controller 40. The controller 40 outputs electric signals to the solenoid valve unit 160 to make the solenoid valves 54a to 59a, 54b to 59b (see below) according to the operation input to the operating devices 1 and 23. Figure 3 as well as Figure 4 ) driven by an electrical signal. The solenoid valves 54 to 59 generate control signals (pilot pressures) for driving the corresponding flow control valves 15a to 15f from the discharge pressure of the pilot pump 48 according to the electrical signals input from the controller 40, and send the control signals (pilot pressures) to the hydraulic drive parts 150a to 155a, 150b to 155b of the flow control valves 15a to 15f via the pilot lines 144a to 149a, 144b to 149b.

[0051] The pressure oil discharged from the hydraulic pump 2 is supplied to the right travel hydraulic motor 3a, the left travel hydraulic motor 3b, the swing hydraulic motor 4, the boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 via the flow control valves 15a to 15f. The boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 are extended and retracted by the pressure oil supplied from the hydraulic pump 2, thereby rotating the boom 8, the arm 9, and the bucket 10, respectively, and the position and posture of the bucket 10 are changed. In addition, the swing hydraulic motor 4 is rotated by the pressure oil supplied from the hydraulic pump 2, thereby rotating the upper swing body 12 relative to the lower travel body 11. In addition, the right travel hydraulic motor 3a and the left travel hydraulic motor 3b are rotated by the pressure oil supplied from the hydraulic pump 2, thereby traveling the lower travel body 11.

[0052] The boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 are provided with load detection devices 16a to 16f for detecting cylinder pressure. The load detection device 16 is, for example, a pressure sensor, which is provided at the bottom side and the rod side of each of the boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7, detects the pressure and outputs it to the controller 40 as an electrical signal. Figure 2 In FIG. 1 , illustration of connection lines for transmitting electric signals from the load detection devices 16 a to 16 f to the controller 40 is omitted.

[0053] The engine 18 includes an engine speed detection device 490 which is a rotation sensor for detecting the engine speed.

[0054] The discharge piping of the pilot pump 48, i.e., the pump line 148a, is connected to each solenoid valve 54 to 59 in the solenoid valve unit 160 via the lock valve 39. The lock valve 39 is, for example, an electromagnetic switching valve, and the electromagnetic drive unit is electrically connected to a position detector of a door lock lever (not shown) arranged in the cab. That is, the position detector detects the position of the door lock lever, and a signal corresponding to the position of the door lock lever is input from the position detector to the lock valve 39, thereby switching the lock valve 39 between a flow state and a cut-off state. For example, when the position of the door lock lever is in the lock position, the lock valve 39 is closed and the pump line 148a is cut off, and the supply of the pilot pressure from the pilot pump 48 to the solenoid valves 54 to 59 of the solenoid valve unit 160 is cut off, thereby invalidating the operation based on the operating device 1, 23 (or the operating device 801, 823), and prohibiting the hydraulic excavator 100 from traveling, rotating, digging, etc. In addition, when the door locking rod is in the unlocked position, the locking valve 39 is opened and the pump line 148a is unblocked, allowing the pilot pressure to be supplied from the pilot pump 48 to the solenoid valves 54 to 59 of the solenoid valve unit 160, thereby enabling the operation based on the operating devices 1, 23 (or operating devices 801, 823) to be effective, and actions such as driving, rotating, and digging can be performed.

[0055] <Solenoid valve unit 160>

[0056] Figure 3 and Figure 4 is a diagram showing the detailed structure of the solenoid valve unit, Figure 3 This is a diagram showing the structures of the boom cylinder, arm cylinder, and bucket cylinder. Figure 4 This is a diagram showing the structures of the travel hydraulic motor and the swing hydraulic motor in an extracted manner.

[0057] like Figure 3 and Figure 4 As shown, the front control electromagnetic valve unit 160 includes electromagnetic proportional valves 54a to 59b whose primary port side is connected to the pilot pump 48 via the pump line 148a and which reduce the pilot pressure from the pilot pump 48 and output it to the pilot lines 144a to 149b.

[0058] The electromagnetic proportional valves 54a to 59a, 54b to 59b have the smallest opening when not energized, and the larger the control signal, i.e., the current, from the controller 40, the larger the opening. In this way, the opening of each electromagnetic proportional valve 54a to 59a, 54b to 59b corresponds to the control signal from the controller 40. In the electromagnetic valve unit 160, the electromagnetic proportional valves 54a to 59b are driven by outputting a control signal from the controller 40, so that a pilot pressure can be generated even when there is no operator operation of the corresponding operating device 1, 23 (or the operating device 801, 823), so that the operation of each hydraulic actuator 3 to 7 can be forcibly generated.

[0059] <Controller 40>

[0060] Figure 5 It is the hardware structure diagram of the controller.

[0061] exist Figure 5 In the controller 40, an input interface 91, a central processing unit (CPU) 92 as a processor, a read-only memory (ROM) 93 and a random access memory (RAM) 94 as storage devices, and an output interface 95 are input to the input interface 91. The input interface 91 inputs a signal indicating an operation amount from the operating device 1, 23, a signal from the boom angle sensor 30, the arm angle sensor 31, the bucket angle sensor 32, the vehicle body tilt angle sensor 33 and the rotation angle sensor 34 as a posture detection device, a signal from the engine speed setting device 480, a signal input via the communication device 650, a signal from the load detection device 16a to 16f, and a signal from the remote ride selection device 670, and converts the signal into a form that can be calculated by the CPU 92 (for example, A / D conversion). The ROM 93 is a recording medium that stores a control program for executing the flowchart described later and various information required for executing the flowchart. The CPU 92 performs a predetermined calculation process on the signal taken from the input interface 91 and the memory 93, 94 according to the control program stored in the ROM 93. The output interface 95 generates an output signal corresponding to the calculation result in the CPU 92, and outputs the signal to the engine controller 470 and the electromagnetic proportional valves 54 to 59 of the electromagnetic valve unit 160, thereby driving and controlling the engine 18 and the hydraulic actuators 3 to 7. Figure 5 The controller 40 shown in the figure illustrates a case where semiconductor memories such as ROM 93 and RAM 94 are provided as storage devices, but any device having a storage function may be substituted, for example, a magnetic storage device such as a hard disk drive may be provided.

[0062] Figure 6 This is a functional block diagram showing the processing functions of the controller.

[0063] like Figure 6 As shown, the controller 40 includes a solenoid proportional valve control unit 44 , a target motion calculation unit 700 , a communication status determination unit 710 , a slow or slow determination unit 720 , an operation signal selection unit 730 , and an engine speed setting signal selection unit 740 .

[0064] When the boarding operation state is selected through the remote boarding selection device 670, the operation signal selection unit 730 selects the signal from the operating device 1, 23 and outputs it to the target action calculation unit 700. When the remote operation state is selected through the remote boarding selection device 670, the operation signal selection unit 730 selects the signal equivalent to the operation signal (i.e., the signal from the operating device 801, 823) from the signal received by the communication device 650 and outputs it to the target action calculation unit 700.

[0065] When the boarding operation state is selected through the remote boarding selection device 670, the engine speed setting signal selection unit 740 selects the signal from the engine speed setting device 480 and outputs it to the target action calculation unit 700 and the engine controller 470. When the remote operation state is selected through the remote boarding selection device 670, the engine speed setting signal selection unit 740 selects the signal corresponding to the engine speed setting signal (i.e., the signal from the engine speed setting device 880) from the signal received by the communication device 650 and outputs it to the target action calculation unit 700 and the engine controller 470.

[0066] The communication status determination unit 710 extracts information (time information) related to the time when the remote control device 800 transmits the signal from the signal received by the communication device 650, calculates the difference from the time when the communication device 650 receives the signal as the communication delay time Tc, determines that it is a communication delay state when the communication delay time Tc is greater than a predetermined threshold value Tc0, and outputs the determination result and the communication delay time Tc to the target motion calculation unit 700. In addition, the communication status determination unit 710 determines that it is a normal communication state when the communication delay time Tc is less than the predetermined threshold value Tc0, and outputs the determination result and the communication delay time Tc to the target motion calculation unit 700.

[0067] The slow deceleration determination unit 720 determines whether to perform slow deceleration based on the signals of the sensors 30 to 34 as the posture detection device and the pressure sensors 16a to 16f as the load detection device, and outputs the determination result (slow deceleration flag) and the deceleration acceleration when slow deceleration is performed (slow deceleration determination processing). The details of the slow deceleration determination processing are described later.

[0068] The target motion calculation unit 700 calculates the target actuator speed of the hydraulic actuator corresponding to the operation of the operating device 1, 23 (or the operating device 801, 823) based on the operation signal selected and output by the operation signal selection unit 730 and the signal selected and output by the engine speed setting signal selection unit 740, and corrects the target actuator speed based on the determination results of the communication status determination unit 710 and the deceleration determination unit 720, and outputs the corrected target actuator speed to the electromagnetic proportional valve control unit 44 (target actuator speed calculation correction processing). The details of the target actuator speed calculation correction processing will be described later.

[0069] The electromagnetic proportional valve control unit 44 generates a control signal (control command value) corresponding to the target actuator speed output from the target motion calculation unit 700 , and outputs the control signal to the corresponding electromagnetic proportional valves 54 to 59 .

[0070] <Slow deceleration determination process (slow deceleration determination unit 720)>

[0071] Fig. 9 1 is a flowchart showing a slow deceleration determination process performed by a slow deceleration determination unit.

[0072] First, the slow deceleration determination unit 720 determines whether to implement slow deceleration based on the signals detected from the posture detection devices 30 to 34 (step S400 ), and then calculates the deceleration acceleration αp corresponding to the posture information (step S410 ).

[0073] In parallel with the processing of steps S400 and S410 , it is determined whether to implement slow deceleration based on the signals detected from the load detection devices 16 a to 16 f (step S401 ), and then the deceleration acceleration α1 corresponding to the load information is calculated (step S411 ).

[0074] When the processing of steps S410 and S411 is completed, the deceleration acceleration αp and the deceleration acceleration αl having a smaller absolute value are output (step S420).

[0075] In addition, in the determination results of steps S400 and S401, it is determined whether at least one of the determination results is a determination result that slow deceleration is implemented (step S430). If the determination result is "yes", that is, if there is a determination result that slow deceleration is implemented, a slow deceleration flag = 1 is output (step S440). In addition, if the determination result in step S430 is "no", that is, if there is a determination result that slow deceleration is not implemented, a slow deceleration flag = 0 (zero) is output (step S441).

[0076] Here, as a method for determining whether to implement slow deceleration in steps S400 and S401, there is a method using the ZMP (Zero Moment Point) equation, for example. When the ZMP method is used, the stability is evaluated based on the deceleration acceleration when the hydraulic excavator 100 is assumed to be in an emergency stop, and whether to implement slow deceleration is determined based on the evaluation result. In addition, the determination of implementation of slow deceleration is not limited to the above method, and for example, a fixed value may be obtained based on a previous simulation or actual machine test, or the determination may be made based on a predetermined determination threshold for a specified posture.

[0077] <Target actuator speed calculation correction process (target motion calculation unit 700)>

[0078] Fig.10 : is a flowchart showing the target actuator speed calculation and correction processing of the target motion calculation unit.

[0079] First, the target motion calculation unit 700 calculates the target motion based on the operation signal output by the operation signal selection unit 730 and the engine speed setting signal output by the engine speed setting signal selection unit 740 based on a predetermined table (see Fig.11 ) to calculate the target speed of the actuator (step S500).

[0080] Next, it is determined whether to impose operation restrictions based on the determination result output by the communication status determination unit 710 (step S510). If the determination result of the communication status determination unit 710 is a communication delay state, operation restrictions are imposed, and if the communication is a normal state, operation restrictions are not imposed.

[0081] If the result of determination in step S510 is "yes", that is, if the result of determination in the communication status determination unit 710 is a communication delay state, a predetermined table (see Fig.12 ), a deceleration coefficient K is calculated based on the communication delay time Tc, and the target speed of the actuator obtained in step S500 is multiplied by the deceleration coefficient K to calculate a limited target speed (step S520).

[0082] Next, it is determined whether the determination result of the slow deceleration determination unit 720 is to implement slow deceleration (step S530). If the determination result is "yes", the target speed of the actuator is output so that the target speed of the actuator calculated in S520 is achieved according to the deceleration acceleration α (step S540).

[0083] In addition, when the judgment result in step S510 is "No", that is, when the communication is normal and no action restriction is performed, or when the judgment result in step S530 is "No", that is, when no slow deceleration is implemented, the target speed of the actuator obtained in step S500 or step S520 is output as the final value.

[0084] The effects of the present embodiment configured as described above will be described.

[0085] Fig.13 is a diagram showing an example of how the communication delay time changes over time. Fig.14 is a diagram showing an example of how the deceleration coefficient K changes with time. Fig.15 This is a diagram showing an example of how the actuator target speed changes over time.

[0086] like Fig.13 2 shows an example in which the communication delay time Tc changes from Tce0 to Tce1 at time T0. In addition, the hydraulic excavator 100 is in a state where sufficient earth and sand are accumulated in the bucket 10 and it is determined that a slow deceleration is required.

[0087] (1) Before time T0

[0088] Before time T0, the communication delay time Tc is Tce0 and is less than the threshold value Tc0, so the communication status determination unit 710 determines that the action restriction is not necessary. Therefore, in the target action calculation unit 700, the action restriction based on the communication status is not turned on (refer to Fig.10 S510), so the target speed Vt of the actuator is directly output (refer to Fig.10 S500) (Refer to Fig.15 ).

[0089] (2) Regarding time T0 to T1

[0090] like Fig.13 As shown, after time T0, the communication delay time Tc becomes Tce1. Since Tce1 is greater than the threshold value Tc0, the communication status determination unit 710 determines that action restriction is required. At this time, the action restriction is turned on in the target action calculation unit 700 (refer to Fig.10 S510), calculate the restricted target speed (refer to Fig.10 S520).

[0091] like Fig.14 As shown in FIG. 1 , since the deceleration coefficient when the communication delay time Tc is Tce1 is Ke, the target speed Vt (refer to Fig.10 Vt×Ke is obtained by multiplying S500 of the actuator by Ke as the target speed ( Fig.10 S520).

[0092] In addition, the slow deceleration determination unit 720 determines to perform slow deceleration according to the load status of the bucket (see Fig.10 S530) outputs the deceleration acceleration α at this time. Fig.15 As in the section from T0 to T1 of FIG. 1 , the target speed of the actuator is outputted so that the deceleration acceleration becomes α (the slope is α).

[0093] (3) After time T1

[0094] After time T1, although it is determined that the vehicle is to be decelerated slowly (see Fig.10 S530), but the deceleration has been completed, so Vt×Ke is output as the target speed of the actuator.

[0095] (4) When the communication delay time Tc is greater than or equal to Tc1

[0096] In the above (1) to (3), the case where the communication delay time Tc changes from Tce0 to Tce1 is exemplified, but Fig.14 In the example, the deceleration coefficient K is set to 0 (ie, Ke=0) when the communication delay time Tc is longer than the predetermined Tc1. In this case, when the communication delay time becomes longer than Tc1, Fig.15 Since the illustrated actuator speed Vt×Ke becomes 0 (zero), the operation of the actuator can be stopped reliably.

[0097] In the present embodiment configured as described above, it is possible to suppress the scattering of the cargo due to an emergency stop and the deterioration of the workability due to the reduction in the stability of the working machine, and to appropriately limit the operation according to the communication status.

[0098] <Second embodiment>

[0099] Reference Fig.16 A second embodiment of the present invention will be described.

[0100] This embodiment exemplifies the calculation of the limited actuator target speed in the first embodiment (see Fig.10 The case where different tables are used in S520).

[0101] Fig.16 1 is a diagram showing an example of a table defining the relationship between the communication delay time and the deceleration coefficient. In the figure, the same reference numerals are used for the same items as those in the first embodiment, and the description thereof is omitted.

[0102] like Fig.16As shown, in this embodiment, when the restricted actuator target speed is calculated in the target motion calculation unit 700 (see Fig.10 ), the actuator target speed is set to 0 (zero).

[0103] In this case, Fig.15 Vt×Ke is replaced by 0 (zero), and the operation of the hydraulic excavator 100 finally stops. However, since the deceleration is gradually performed, it is possible to prevent the deterioration of the working efficiency as in the first embodiment.

[0104] <Note>

[0105] In addition, the present invention is not limited to the above-mentioned embodiment, and includes various modifications and combinations within the scope of the gist thereof. In addition, the present invention is not limited to having all the structures described in the above-mentioned embodiment, and also includes a structure in which a part of the structure is deleted.

[0106] For example, in the embodiment of the present invention, an angle sensor is used to detect the angles of the boom 8, the arm 9, and the bucket 10, but the posture information of the excavator may be calculated by a cylinder stroke sensor instead of an angle sensor. Furthermore, although the electric lever excavator is described as an example, if it is a hydraulic pilot excavator, it may be configured to control the command pilot pressure generated from the hydraulic pilot.

[0107] Furthermore, in the embodiments of the present invention, the hydraulic excavator is described as an example, but the present invention is not limited to this, and can be applied to other working machines such as a wheel loader and a crane, for example.

[0108] In the embodiment of the present invention, the controller 40 of the hydraulic excavator 100 has all functions, but a part of the functions may be arranged in the remote control device 800 or a server through which communication is performed.

[0109] In the embodiment of the present invention, the target speed of the actuator is limited. However, the operation signal as the input signal may be limited or the engine speed may be reduced.

[0110] In addition, in an embodiment of the present invention, the communication delay time Tc is calculated by the difference between the sending time of the remote control device 800 and the receiving time of the communication device 650, but it is also possible that the communication device 650 sends a signal to the remote control device 800, and the remote control device 800 directly returns the signal to the communication device 650, and the communication delay time Tc is calculated based on the round-trip time.

[0111] In addition, in an embodiment of the present invention, a calculation unit for calculating the communication delay time Tc is set in the controller 40 of the hydraulic excavator 100, but is not limited to this. It can also be configured to be set in the remote control device 800, or a server that communicates between the remote control device 800 and the communication device 650, and send the communication delay time Tc to the communication device 650.

[0112] In addition, the above-mentioned structures, functions, etc. may be realized by designing part or all of them in an integrated circuit, etc. In addition, the above-mentioned structures, functions, etc. may be realized by software by a processor interpreting and executing a program realizing each function.

[0113] Description of Reference Numerals

[0114] 1...operating device; 1a...operating right lever; 1A...front working device; 1b...operating left lever; 1B...vehicle body; 2...hydraulic pump; 2aa, 2ba...regulator; 3a, 3b...travel hydraulic motor; 4...rotation hydraulic motor; 5...boom cylinder; 6...arm cylinder; 7...bucket cylinder; 8...boom; 9...arm; 10...bucket; 11...lower travel body; 12...upper rotation body; 13...bucket connecting rod; 15a~15f...flow control valve; 16a~16f...pressure sensor; 18...engine; 23...operating device; 30~32...angle sensor; 33...vehicle body tilt angle sensor; 34...rotation angle sensor; 39...locking valve; 40...controller; 44...electromagnetic proportional valve control unit; 48...pilot pump; 54...electromagnetic proportional valve; 91...input interface ; 92...CPU; 93...ROM; 94...RAM; 95...output interface; 100...hydraulic excavator; 160...solenoid valve unit; 470...engine controller; 480...engine speed setting device; 490...engine speed detection device; 650...communication device; 670...remote boarding selection device; 700...target action calculation unit; 710...communication status determination unit; 720...slow deceleration determination unit; 730...operation signal selection unit; 740...engine speed setting signal selection unit; 800...remote control device; 801...operation device; 801a...operation device; 801b...operation device; 810...display device; 823...operation device; 823a...operation device; 823b...operation device; 850...communication device; 880...engine speed setting device.

Claims

1. A working machine having a front working device, characterized in that: The working machine comprises: a state quantity detecting device for detecting a state quantity related to an operation state of the front working device; and a control device for controlling the operation of the working machine based on an operation signal transmitted from a remote control device via wireless communication, The state quantity detection device comprises: a posture detection device for detecting information related to the posture of the working machine, that is, posture information; and a load detection device for detecting information related to the load of the front working device of the working machine, that is, load information. The control device evaluates the communication status of the wireless communication, and when limiting the movement of the working machine based on the evaluation result, relaxes the restriction on the movement of the working machine in a manner that relaxes the restriction on the movement corresponding to the posture information as the detection result of the state quantity detection device and relaxes the restriction on the movement corresponding to the load information to a greater extent.

Images