JP7231444B2 - working machine - Google Patents

Description

The present invention relates to working machines.

When a work machine (e.g., hydraulic excavator) equipped with a work machine driven by a hydraulic actuator (e.g., a multi-joint front work machine consisting of a boom, arm, and attachment) is used for excavation, loading, etc., the work machine There may be an obstacle (for example, a structure such as a building) on the side of the In addition, there are work sites that are close to areas such as general roads that work equipment should not enter (hereinafter referred to as "intrusion prohibited areas"). The work machine operator must operate the work machine so as to avoid contact with these structures and intrusion into restricted areas.

As a technology to support operator operations in such an environment, there is a technology to set a work area outside the no-entry area and prevent the work machine from deviating from it to avoid entering the no-entry area. Patent Document 1 discloses an electric motor that rotates a rotor relative to a stator to drive an upper rotating body to rotate, an angular velocity detecting means that detects the angular velocity of the rotor as the motor angular velocity, and a rotating operation lever that detects the angular velocity of the rotor. Electric motor control means for controlling the rotational speed of the electric motor so as to correspond to the set turning speed, and turning angle calculating means for calculating the turning angle of the upper turning structure based on the time integral value of the motor angular speed. , swing range setting means for setting a swing range (work area) of the upper swing body, and stop control means for stopping the operation of the electric motor so that the swing angle does not exceed the swing range A controller is disclosed.

Further, in Patent Document 2, a controller determines a turning braking start timing for stopping the turning body at a turning stop angle position at a predetermined turning deceleration and a target turning angular velocity after that based on the remaining turning angle of the turning body. Angular velocity control is executed, and regardless of this control, disturbances (i.e., external forces that can resist turning (e.g., gravity and wind acting on the upper slewing structure in a tilted posture)) may cause a movement before the slewing stop angle position. Disclosed is a swing stop control device and method for a swing type work machine that generates a restartable swing torque by increasing a target swing angular velocity when the swing body stops at a position.

JP 2011-52383 A JP 2010-247968 A

These prior art documents disclose control (swing braking control) for applying a braking force (braking torque) to a work machine (swing body) during a swing motion to stop the work machine at a predetermined swing angle. However, it does not take into account that the front work equipment is operated until the swing body stops due to the braking force, and that the length and moment of inertia of the front work equipment change.

First, regarding the length of the front work equipment (arm), for example, if a linear work area is defined on the side of the front work equipment, even if the same braking torque is applied at the same turning angle, the front work equipment ( Depending on the length of the arm), it may or may not deviate from the work area. However, since such a situation is not taken into consideration in the above prior art documents, depending on the length of the front work equipment, even if it is stopped at a predetermined turning angle, the front work equipment may deviate from the work area (i.e., entry is prohibited). area).

In addition, the latter moment of inertia changes depending on the attitude of the front work equipment and affects swing motion, so it must be taken into account when braking swing motion. Swing braking is applied to prevent deviation from the work area, and if the front work equipment is operated while the swing motion is decelerating, the moment of inertia of the front work equipment will fluctuate according to changes in the posture of the front work equipment. If the front work equipment is operated in a direction that increases the moment of inertia, the swing braking angle, which is the swing angle from when swing braking is performed until it stops, increases, and there is a possibility that it will deviate from the work area. In order to avoid such a situation, for example, if conservative control is implemented to prevent deviation based on a situation where the moment of inertia is always large, the front work equipment will stop far away from the boundary of the work area. The operator's operation and the actual operation of the work machine are greatly different from each other, giving the operator a sense of discomfort. In addition, if the operation of the front work equipment is disabled or prohibited while the swing braking is being performed to prevent departure, the moment of inertia will not change, but the operation of the front work equipment during the swing braking will not occur. gives the operator who desires a sense of incompatibility.

SUMMARY OF THE INVENTION The object of the present invention is to provide a work machine that can prevent malfunctions caused by operating the front work equipment in the execution of swing braking control that applies a braking force to the swing body during swing motion to stop it at a predetermined swing angle. to provide.

The present application includes a plurality of means for solving the above problems. Based on the attached work machine, the position of the work area set in advance, and the posture of the upper revolving body and the work machine, the upper part is moved before the upper revolving body and the work machine deviate from the work area. A control device that calculates a target swing stop angle, which is a target value of the swing angle for stopping the swing of the swing structure, and outputs a swing stop command to stop the upper swing structure during swing at the target swing stop angle. , the control device assumes that swing braking by a predetermined braking torque and maximization of the reach length of the work machine have started, and from when the swing stop command is output, Predicted swing braking angle, which is the angle at which the upper swing structure swings during the braking period, which is the period until the upper swing structure stops, and the reach length of the work machine until the upper swing structure stops A predicted work machine reach, which is a change, is calculated based on the attitude and speed of the work machine and the swing angular velocity of the upper swing body, and when the upper swing body swings with the predicted work machine reach, the work machine reaches deviates from the work area, and if it is determined that a part of the work machine deviates from the work area, the predicted work machine reach, the upper revolving body and the work area correcting the target turning stop angle based on the distance d from the boundary of and outputting the turning stop command at a timing determined based on the predicted turning braking angle and the corrected target turning stop angle characterized by

According to the present invention, it is possible to prevent the occurrence of problems due to the operation of the front work equipment during swing braking control.

1 is a configuration diagram of a hydraulic excavator according to an embodiment of the present invention; FIG. FIG. 2 is a diagram showing a controller of the hydraulic excavator of FIG. 1 together with a hydraulic drive; FIG. 3 is a detailed view of the control hydraulic unit in FIG. 2; FIG. 2 is a hardware configuration diagram of a controller of the hydraulic excavator in FIG. 1; FIG. 2 is a diagram showing a coordinate system (excavator reference coordinate system) in a hydraulic excavator; FIG. 2 is a functional block diagram of a controller according to the first embodiment of the present invention; The figure which shows the positional relationship of the work area and excavator which concern on embodiment of this invention. FIG. 2 is a diagram showing a flowchart of departure prevention control according to the first embodiment of the present invention; The figure which shows the flowchart of the deviation prevention control which concerns on 2nd Embodiment of this invention. The functional block diagram of the control controller based on 3rd Embodiment of this invention. The figure which shows the correlation table of a pilot pressure and an actuator speed. FIG. 10 is a diagram showing part of a flowchart of departure prevention control according to a modification of the first embodiment of the present invention; The figure which shows the positional relationship of the work area and excavator which concern on embodiment of this invention. FIG. 4 is a functional block diagram of a controller according to a modification of the first embodiment of the present invention;

An embodiment of the present invention will be described below with reference to the drawings. Although a hydraulic excavator having a bucket as a working tool (attachment) at the tip of the working machine is exemplified below as a working machine, the present invention may be applied to a working machine having an attachment other than a bucket. In addition, if it has a multi-joint type work machine configured by connecting multiple link members (attachment, boom, arm, etc.) on a swingable structure, it can be used as a work machine other than a hydraulic excavator. can also be applied.

In addition, in the following explanation, when there are multiple identical components, a lowercase letter of the alphabet may be added to the end of the code. There is For example, when there are three identical pumps 190 a , 190 b , 190 c , these may be collectively referred to as pump 190 .

<First Embodiment>
FIG. 1 is a block diagram of a hydraulic excavator according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a controller (control device) 40 of the hydraulic excavator according to the embodiment of the present invention together with a hydraulic drive system. 3 is a detailed view of the front control hydraulic unit 160 in FIG.

In FIG. 1, a hydraulic excavator 1 is composed of an articulated front working machine 1A and a vehicle body (machine body) 1B. A vehicle body (machine body) 1B includes a lower traveling body 11 that travels by left and right traveling hydraulic motors 3a and 3b, and an upper swinging section mounted on the lower traveling body 11 that is driven by a turning hydraulic motor 4 and capable of turning left and right. body 12;

The front working machine 1</b>A is configured by connecting a plurality of front members (boom 8 , arm 9 and bucket 10 ) that rotate in the vertical direction, and is attached to an upper revolving body 12 . The base end of the boom 8 is rotatably supported at the front portion of the upper swing body 12 via a boom pin. An arm 9 is rotatably connected to the tip of the boom 8 via an arm pin, and a bucket 10 is rotatably connected to the tip of the arm 9 via a bucket pin. A boom 8 is driven by a boom cylinder 5 , an arm 9 is driven by an arm cylinder 6 and a bucket 10 is driven by a bucket cylinder 7 .

A boom angle sensor 30 is attached to the boom pin, an arm angle sensor 31 is attached to the arm pin, and a bucket angle sensor is attached to the bucket link 14 so that the rotation angles α, β, γ (see FIG. 5) of the boom 8, arm 9, and bucket 10 can be measured. 32 is attached to the upper revolving body 12, and a vehicle body tilt angle sensor 33 is attached to detect the tilt angle θ (see FIG. 5) of the upper revolving body 12 (vehicle body 1B) with respect to a reference plane (for example, a horizontal plane). The angle sensors 30, 31, and 32 can be replaced by angle sensors (for example, inertial measurement units (IMUs)) that detect angles with respect to a reference plane (for example, a horizontal plane). Alternatively, a cylinder stroke sensor for detecting the stroke of each hydraulic cylinder 5, 6, 7 may be substituted, and the obtained cylinder stroke may be converted into an angle.

A turning angle sensor 19 capable of detecting the relative angle (turning angle θ _sw ) between the upper turning body 12 and the lower traveling body 11 is attached near the center of rotation of the upper turning body 12 and the lower traveling body 11 . A turning angular velocity sensor 17 capable of detecting a turning angular velocity is attached to the upper turning body 12 .

An operating device 47a (FIG. 2) having a right traveling lever 23a (FIG. 1) for operating a right traveling hydraulic motor 3a (lower traveling body 11) and a traveling An operating device 47b (FIG. 2) having a left lever 23b (FIG. 1) for operating the traveling left hydraulic motor 3b (lower traveling body 11) and a boom cylinder 5 (FIG. 1) sharing the operating right lever 22a (FIG. 1). The operating devices 45a and 46a (Fig. 2) for operating the boom 8) and the bucket cylinder 7 (bucket 10) and the left operating lever 22b (Fig. 1) are shared to operate the arm cylinder 6 (arm 9) and swing hydraulic motor 4. Operating devices 45b and 46b (FIG. 2) for operating the (upper rotating body 12) are installed. The right operation lever 22a, the left operation lever 22b, the right travel lever 23a, and the left travel lever 23b may be collectively referred to as the operation levers 22 and 23 below.

An engine 18 that is a prime mover mounted on the upper swing structure 12 drives the hydraulic pump 2 and the pilot pump 48 . The hydraulic pump 2 is a variable displacement pump whose displacement is controlled by a regulator 2a, and the pilot pump 48 is a fixed displacement pump. In this embodiment, shuttle blocks 162 are provided in the middle of the pilot lines 144, 145, 146, 147, 148 and 149, as shown in FIG. Hydraulic signals output from the operating devices 45, 46 and 47 are also input to the regulator 2a via the shuttle block 162. Although the detailed configuration of the shuttle block 162 is omitted, a hydraulic signal is input to the regulator 2a via the shuttle block 162, and the discharge flow rate of the hydraulic pump 2 is controlled according to the hydraulic signal.

The operation devices 45, 46, 47 are of a hydraulic pilot type, and based on the pressure oil discharged from the pilot pump 48, the operation amount (for example, lever stroke) of the operation levers 22, 23 operated by the operator, respectively. A pilot pressure (also referred to as an operation pressure) is generated according to the operation direction. The pilot pressure generated in this way is supplied to the hydraulic drive units 150a to 155b of the corresponding flow control valves 15a to 15f (see FIG. 2) in the control valve unit 20 via pilot lines 144a to 149b (see FIG. 2). and used as control signals for driving these flow control valves 15a to 15f.

The pressure oil discharged from the hydraulic pump 2 is supplied to the right traveling hydraulic motor 3a, the left traveling hydraulic motor 3b, the turning hydraulic motor 4, It is supplied to boom cylinder 5 , arm cylinder 6 and bucket cylinder 7 . The boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 are extended and contracted by the supplied pressure oil, so that the boom 8, the arm 9, and the bucket 10 are rotated, and the position and posture of the bucket 10 are changed. Further, the hydraulic hydraulic motor 4 is rotated by the supplied pressure oil, so that the upper swing body 12 swings with respect to the lower traveling body 11 . Then, the right traveling hydraulic motor 3a and the left traveling hydraulic motor 3b are rotated by the supplied pressure oil, so that the lower traveling body 11 travels. Hereinafter, the travel hydraulic motor 3, swing hydraulic motor 4, boom cylinder 5, arm cylinder 6, and bucket cylinder 7 may be collectively referred to as a hydraulic actuator 3-7.

FIG. 4 is a configuration diagram of a departure prevention control system (swing braking control system) provided in the hydraulic excavator according to this embodiment. In the system of FIG. 4, when the operator inputs a turning operation to the operation lever 22b and the upper turning body 12 turns, the excavator 1 (more specifically, the excavator 1) moves out of a preset work area in which movement of the excavator 1 is permitted. Departure prevention that forcibly decelerates or stops the swing hydraulic motor 4 in order to prevent the front work machine 1A and the upper swing body 12) from deviating (that is, to prevent entry into the prohibited area). It is the one that executes the control. In particular, in the present embodiment, the turning motion is controlled to prevent deviation from the work area, so this control is called "turn braking control".

In swing braking control, when operation of the swing hydraulic motor 4 is instructed by operating the operating lever 22b, the positional relationship between the boundary of the work area 60 (work area boundary) 61 (see FIG. 7) and the hydraulic excavator 1 is controlled. , to the flow control valve 15d to limit the operation of the swing hydraulic motor 4 to approach the work area boundary 61, thereby preventing the hydraulic excavator 1 from deviating from the work area.

According to the deviation prevention control system, each part of the excavator 1 can be prevented from deviating from the work area 60 (see FIG. 7). It is possible to concentrate on the original work of Note that the example of FIG. 7 shows a working area 60 set along the side surface of the excavator 1 (the side surface of the lower traveling body 11).

The system shown in FIG. 4 includes a work machine attitude detection device 51, a work area setting device 52, an operator operation detection device 53, a turning angle detection device 54, a turning angular velocity detection device 55, and a control controller (controller) in charge of departure prevention control. device) 40, a display device 83 capable of displaying the positional relationship between the working area 60 and the hydraulic excavator 1, and electromagnetic proportional valves 87 (87a, 87b).

The working machine posture detection device 51 is a sensor for detecting the posture information of the upper revolving body 12 (body 1B) and the front working machine 1A. It is composed of an angle sensor 32 and a vehicle body tilt sensor 33 which is an IMU attached to the upper swing body 12 .

The turning angle detection device 54 is composed of a turning angle sensor 19 that detects the relative angle (turning angle θ _sw ) between the upper turning body 12 and the lower traveling body 11 .

The turning angular velocity detector 55 is composed of a turning angular velocity sensor 17 that detects the turning angular velocity of the upper turning body 12 . The turning angular velocity can also be obtained from the difference (change over time) of the turning angle θ _sw detected by the turning angle detection device 54 (turning angle sensor 19). In this case, the turning angular velocity sensor 17 can be omitted. .

The work area setting device 52 is an interface capable of setting the work area 60 of the hydraulic excavator 1 as shown in FIG. The operator may manually set the work area 60 via the work area setting device 52. Alternatively, the work area setting device 52 may be connected to an external terminal, and the work area 60 set by the external terminal may be swiveled. It can be used for control. Also, the work area 60 can be set, for example, on a local coordinate system (excavator reference coordinate system) set in the hydraulic excavator 1 (for example, the lower traveling body 11). In addition, it is also possible to set on a desired coordinate system such as a global coordinate system (geographical coordinate system) or a site coordinate system set at the site. When the work area 60 is set on the global coordinate system, two GNSS (Global Navigation Satellite System) antennas 56 are attached to the hydraulic excavator 1 , and the global navigation of the hydraulic excavator 1 is performed based on the satellite signals received by the GNSS antennas 56 . The turning braking control may be executed by calculating the coordinates and reading the work area 60 existing within a predetermined range from the coordinates into the controller 40 .

The operator operation detection device 53 includes pressure sensors 70a to 75a and pressure sensors 70b to 75b (see FIG. 2) for detecting the operation pressure generated in the pilot lines 144 to 149 shown in FIG. consists of In other words, the operator operation detection device 53 (pressure sensors 70 to 75) detects the operator's operation on the hydraulic actuator 3-7.

The controller 40 controls the upper revolving body 12 before the upper revolving body 12 and the front work machine 1A deviate from the work area 60 based on the position of the work area 60 and the attitudes of the upper revolving body 12 and the front work machine 1A. A target turning stop angle θstop (described later), which is a target value of the turning angle for stopping the turning, is calculated, and turning stop is performed for turning braking control to stop the upper turning body 12 during turning at the target turning stop angle. Output commands. The controller 40 performs swing braking control by appropriately changing the operating pressure generated in the pilot lines 147a and 147b by the operator's operation of the operating lever 22b by means of the control hydraulic unit 160 (see FIG. 2). FIG. 3 shows details of the control hydraulic unit 160. As shown in FIG. As shown in this figure, the control hydraulic unit 160 includes electromagnetic proportional valves 87a and 87b, which are pressure reducing valves, installed in two pilot lines 147a and 147b, respectively. The electromagnetic proportional valves 87a and 87b are electrically connected to the controller 40, and the valve opening degree is controlled based on the control signal output from the controller 40, thereby increasing the operating pressure ( pilot pressure) can be reduced. The proportional solenoid valves 87a and 87b have the maximum opening when not energized, and the opening decreases as the current, which is the control signal from the controller 40, increases. That is, the electromagnetic proportional valves 87a and 87b can generate pilot pressure that is forcibly reduced from the pilot pressure generated by the operator's operation of the control lever 22b.

In this paper, the control output from the controller 40 to the electromagnetic proportional valves 87a and 87b is performed to forcibly stop the swinging upper structure 12 at a target swing stop angle θstop (described later). The signal may be referred to as a "swing stop command". The rotation stop command in this embodiment reduces the operating pressure (pilot pressure) of the pilot lines 147a and 147b. can be Other operating pressures include, for example, rotating the upper rotating body 12 in a direction opposite to the rotating direction specified by the operator's operation. Also, the rotation stop command may change the pilot pressure according to the passage of time or the change in the rotation speed.

A hardware configuration of the controller 40 will be described with reference to FIG. 4, the controller 40 includes 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. have.

The input interface 91 receives signals from the angle sensors 30, 31, 32, and 34 and the tilt angle sensor 33, which are the work machine posture detection device 51, and signals from the work area setting device 52, which is a device for setting the work area 60. A signal, a signal from an operator operation detection device 53 that is a pressure sensor (including pressure sensors 70 to 75) that detects the amount of operation from the operation devices 45 to 47, and a turning angle sensor 19 that is a turning angle detection device 54 , and the signal from the turning angular velocity sensor 17, which is the turning angular velocity detecting device 55, are input and converted so that the CPU 92 can perform calculations.

The ROM 93 is a recording medium that stores a control program for executing departure prevention control (swing braking control) including processing related to the flowcharts described later, and various information necessary for executing the flowcharts. Predetermined arithmetic processing is performed on the signals received from the input interface 91 and the memories 93 and 94 according to the control program stored in the ROM 93 .

The output interface 95 creates an output signal according to the calculation result of the CPU 92, and outputs the signal to the electromagnetic proportional valve 87 (87a, 87b) or the display device 55 to control the swing hydraulic motor 4. Also, images of the front work machine 1A, the vehicle body 1B, the bucket 10, the work area 60, and the like are displayed on the screen of the display device 83.

Although the controller 40 in FIG. 4 has semiconductor memories such as the ROM 93 and the RAM 94 as storage devices, any storage device can be substituted, and for example, a magnetic storage device such as a hard disk drive may be provided.

FIG. 6 is a functional block diagram of the controller 40. As shown in FIG. By executing the program stored in the ROM 93 by the CPU 92, the controller 40 performs a swing angle calculation section 70, a work area calculation section 71, a work machine attitude calculation section 72, a swing angular velocity calculation section 73, and an operator operation section. Functions as a speed estimation unit 74, a display control unit 75, an electromagnetic proportional valve control 76, a target stop angle calculation unit 101, a turning braking behavior prediction unit 102, a target stop angle correction unit 103, and a turning command calculation unit 104. do. Processing in each unit will be described below.

The turning angle calculator 70 calculates the turning angle θ _sw of the upper turning body 12 in the shovel reference coordinate system (local coordinate system) based on the information from the turning angle detection device 54 (turning angle sensor 19).

The work machine attitude calculation unit 72 calculates the attitude of the front work machine 1A in the excavator reference coordinate system. The posture of the hydraulic excavator 1 can be defined on the excavator reference coordinate system shown in FIG. The shovel reference coordinate system in FIG. 5 has the origin at the point where the lower traveling body 11 touches the ground among the turning center axes. The traveling direction when the lower traveling body 11 moves straight is parallel to the action plane of the front working machine 1A, and the operating direction of the extension direction of the front working machine 1A and the moving direction when the lower traveling body 11 is moved forward. A right-handed coordinate system is defined with the X-axis, the Z-axis as the center of rotation of the upper rotating body 12, and the above-described X-axis and Z-axis. As for the turning angle θ _sw , the state in which the front work implement 1A is parallel to the X-axis is defined as 0 degree. The rotation angle of the boom 8 with respect to the X axis is the boom angle α, the rotation angle of the arm 9 with respect to the boom 8 is the arm angle β, the rotation angle of the toe of the bucket 10 with respect to the arm 9 is the bucket angle γ, and the upper structure 12 with respect to the lower structure 11. The turning angle was defined as turning angle θ _sw . The boom angle .alpha _. By using this angle information and the dimension information of each part of the hydraulic excavator 1 stored in advance in the ROM 93, the attitude and position of each part of the hydraulic excavator 1 in the excavator reference coordinate system can be calculated. A vehicle body tilt angle sensor 33 can detect the tilt angle θ of the vehicle body 1B with respect to a horizontal plane (reference plane) perpendicular to the direction of gravity.

Based on the information from the work area setting device 52, the work area calculation unit 71 executes calculation for converting the position information of the work area 60 into the excavator reference coordinate system shown in FIG. Although the work area 60 defined by a single work area boundary 61 as shown in FIG. 7 is shown in this embodiment, the work area 60 may be defined by a plurality of work area boundaries 61 . The work area boundary 61 is not limited to the straight line shown in FIG. 7, but may be a curved line, and is not limited to a straight line substantially parallel to the X axis as shown in FIG.

The operator operation speed estimator 74 calculates the correlation between the pilot pressure (operation pressure) detected by the operator operation detection device 53 (pressure sensors 70 to 75) and the pilot pressure and actuator speed stored in the ROM 93 in the controller 40 in advance. Based on the table (see, for example, FIG. 11), the speed of the hydraulic actuator 3-7 is estimated by the operator's operation. The detection of the amount of operation by the pressure sensors 70 to 75 is merely an example. is detected, the pilot pressure is calculated from the lever operation amount based on the detected lever operation amount and the correlation table of the lever operation amount and the pilot pressure, and further using the spectacle table illustrated in FIG. The speed of the hydraulic actuator 3-7 may be estimated. Further, instead of estimating the operation speed of each hydraulic actuator 3-7 from the operation amount of the operator, the displacement of the hydraulic cylinder 3-7 is calculated from the detection values of the angle sensors 30 to 32 and the vehicle body tilt angle sensor 33, The motion speed may be calculated based on the time change of the displacement.

The turning angular velocity calculator 73 calculates the turning angular velocity of the upper turning body 12 based on the detection value of the turning angular velocity detector 55 (turning angular velocity sensor 17).

The target stop angle calculation unit 101 calculates the position of the work area 60 (work area boundary 61) calculated by the work area calculation unit 71, and the position of the front work machine 1A and the upper swing body 12 calculated by the work machine posture calculation unit 72. A target turning stop angle θstop, which is a turning angle target value for stopping the turning of the upper turning body 12 before the front work implement 1A and the upper turning body 12 deviate from the work area 60, is calculated based on the attitude and the posture. . In the excavator reference coordinate system, the target stop angle calculation unit 101 of the present embodiment calculates the reach length (sometimes simply referred to as “reach”) Rbk (FIG. 5) of the front work machine 1A and the work area boundary from the main body 1B. From the distance to 61, the target turning stop angle θstop is calculated. For example, the calculation of the target turning stop angle θstop when the left end portion 10L of the bucket 10 approaches the work area boundary 61 in FIG. 7 will be described. The distance d (Fig. 7) between the work area boundary 61 and the origin of the excavator reference coordinate system (the turning center 120 of the upper turning body 12), and the length of the X-axis direction between the turning center 120 of the upper turning body 12 and the boom pin 8a is Lsb. (Fig. 5), the length from the boom pin 8a to the arm pin 9a is Lbm (Fig. 5), the length from the arm pin 9a to the bucket pin 10a is Lam (Fig. 5), the length from the bucket pin 10a to the bucket tip 10b is Let Lbk (FIG. 5), Wbk (FIG. 7) be the length of the tip of the bucket in the width direction, and α, β, γ (FIG. 5) be the rotation angles of the boom 8, the arm 9, and the bucket 10. It is assumed that there is no offset between the turning center 120 and the boom pin 8 in the Z-axis direction and the Y-axis direction. At this time, the reach Rbk of the front work implement 1A is represented by the following formula (1).

Assuming that the turning angle is θsw, the position Ybk of the left end 10L of the bucket tip 10b is expressed by the following equation (2).

In the above formula (2), if a, b, and δ are the coefficients obtained by synthesizing the trigonometric functions, and d is the distance between the origin of the excavator reference coordinate system and the work area boundary 61, the target turning stop angle θstop is obtained by the following formula ( 3). The target turning stop angle θstop at this time is the turning angle θsw when the left end 10L of the tip of the bucket is positioned on the work area boundary 61, as shown in FIG. In this case, the left end 10L of the tip of the bucket is the point on the hydraulic excavator 1 that reaches the work area boundary 61 earliest due to the swinging motion of the upper swing body 12 . However, depending on the revolving direction of the upper revolving structure 12 and the position of the work space boundary 61, the point on the hydraulic excavator 1 that reaches the work space boundary 61 earliest due to the revolving motion of the upper revolving structure 12 changes each time. obtain.

The slewing braking behavior prediction unit 102 calculates a period from when a slewing stop command is output from the controller 40 (start of slewing braking) to when the upper slewing body 12 stops (in this paper, it may be referred to as a "braking period"). By predicting the motions of the inner upper revolving body 12 and the front work machine 1A from the revolving angular velocity of the upper revolving body 12 and the attitude of the front work machine 1A, the angle at which the upper revolving body 12 revolves during the braking period is predicted. A turning braking angle θpre is calculated. The swing braking behavior prediction unit 102, for example, at a predetermined timing determined by a control cycle, uses the attitude of the front work implement 1A, the speed of the front work implement 1A, and the angular velocity of the upper swing body 12 at that moment as initial conditions to determine the braking period. Behaviors of the inner upper revolving body 12 and the front work implement 1A are predicted. More specifically, the slewing braking behavior prediction unit 102 predicts the front work machine 1A by changing the rotation angles α, β, and γ of the boom 8, the arm 9, and the bucket 10 during the braking period under the slewing braking control. The predicted value of the reach (also called "predicted work machine reach") Rpre and the angle at which the upper swing body 12 swings during the braking period (that is, the angle required from the start of swing braking to the stop of swing) A predicted value of the turning braking angle (also referred to as a "predicted turning braking angle") θpre is calculated. The change in the reach Rpre of the front work implement 1A and the turning braking angle θpre can be calculated, for example, based on the following equation of motion (4). τ is the turning braking torque, ω is the turning angular velocity, J is the moment of inertia of the upper rotating body 12 that depends on the attitude of the front working equipment 1A (working equipment attitude), B is the viscous damping coefficient, and C is depending on the working equipment attitude. Assuming a term related to centrifugal force, the equation of motion of the upper revolving body 12 is as shown in the following equation (4). By changing the moment of inertia term J and the centrifugal force term C, which are terms that depend on the posture of the work equipment, and solving the following equation (4) at each time, we can obtain , the turning braking angle, and the change in the reach of the front work implement 1A can be calculated.

The change in the reach Rpre of the front work equipment 1A during the braking period is defined based on the speed change of the hydraulic actuator (hydraulic cylinder) 5-7 during the braking period, and the speed change can be calculated by geometrically changing the rotation angles α, β, γ. In this embodiment, the correlation table between the pilot pressure and the hydraulic actuator 5-7 shown in FIG. Further, in the present embodiment, as a method of changing the speed of the hydraulic actuator 5-7 during the braking period, the reach Rbk of the front work implement 1A shown in the equation (2) is calculated from the attitude at the time of calculation (at the present time) to the maximum value. is changing so that it continues to increase during the braking period. From the viewpoint of reliably preventing deviation from the working range 60 , it is preferable to set the amount of increase in the reach Rbk per hour to a theoretical maximum value defined by the specifications of the excavator 1 . Note that if the reach Rbk reaches the maximum value during the braking period, the maximum value is maintained thereafter. By assuming such a change in actuator speed, the swing braking control when the operator operates so that the reach of the front work equipment 1A increases toward the maximum value from the current attitude and speed of the front work equipment 1A. It is possible to predict the behavior of the time, and based on that behavior, it is also possible to calculate the predicted turn braking angle θpre. In other words, it can be said that the turning braking behavior prediction unit 102 of the present embodiment calculates the predicted braking angle θpre on the assumption that the reach Rbk of the front work implement 1A continues to increase during the braking period.

If the reach Rbk of the front work implement 1A is maximized at the current time, the turning braking behavior prediction unit 102 does not assume a change in the posture of the front work implement 1A during the braking period, and (That is, the reach Rbk is the maximum value) and the turning braking angle θpre is calculated.

The target stop angle correction unit 103 corrects the target swing stop angle θstop from the prediction result of the operation of the front work implement 1A by the swing braking behavior prediction unit 102 (specifically, the reach Rpre of the front work implement 1A). Here, the corrected value of the target turn stop angle θstop may be referred to as a corrected turn stop angle θrs. The corrected turning stop angle θrs of the present embodiment is set at a point on the excavator 1 when turning toward the work area boundary 61 while extending the reach of the front work equipment 1A from the current value to the maximum value according to a predetermined rule. The turning angle θsw is obtained when the point that reaches the working area boundary 61 earliest (the left end 10L of the tip of the bucket in FIG. 13) is positioned on the working area boundary 61 . If the reach is not the maximum at the current time, the corrected turning stop angle θrs is usually smaller than θstop as the reach increases. It should be noted that θrs and θstop have the same value when the working machine attitude has reached full reach (maximum value) at the current time. In other words, the target stop angle correction unit 103 of the present embodiment corrects the target swing stop angle θstop on the assumption that the reach Rbk of the front work implement 1A continues to increase during the braking period. It can be said that the angle θrs is calculated.

The turning command calculation unit 104 issues a turning stop command ( A command to decelerate and stop the swinging of the upper swing body 12) is output to the electromagnetic proportional valve 87. In this embodiment, when the condition of the following formula (5) is satisfied, a turning stop command for decelerating with a turning braking torque τ (see formula (4)) is output, and turning braking control is executed. However, in the flowcharts of FIGS. 8 and 9 described later, when the sum of the predicted swing braking angle θpre and the current swing angle θc reaches the corrected swing stop angle θrs (θstop when the work equipment reach is already at its maximum), the braking torque It explains that turning braking is performed by adding τ.

By outputting the rotation stop command at the timing that satisfies the above formula (5), even if the operator performs an operation to maximize the reach of the work implement 1A from the current posture during the braking period, , the turning motion of the excavator 1 can be stopped without deviating from the work area 60 and without restricting the motion of the front working machine 1A.

- Flowchart (Fig. 8) -
Next, based on FIG. 8, the control processing procedure by the hydraulic excavator 1 having the above configuration will be described. FIG. 8 shows a flowchart of deviation prevention control executed by the controller 40 of the present embodiment, where S is attached to each step number. The controller 40 starts the flow of FIG. 8 when the operator performs a turning operation with the operation lever 22b. However, during turning, the flow of FIG. 8 is repeatedly executed at a predetermined cycle.

First, in step S100, based on the position of the work area 60 calculated by the work area calculation unit 71, the controller 40 determines whether the work area 60 is set to the current position of the hydraulic excavator 1 (own machine). determine whether or not For example, it is determined whether or not the work area boundary 61 exists within a predetermined range centered on the position of the machine itself, and if the work area boundary 61 exists within the predetermined range, the work area 60 is set. It is determined that In addition, a switch for switching ON/OFF of the execution of deviation prevention control is provided, and when the switch is turned ON, the work area 60 is set, and when it is OFF, the work area 60 is not set. Some judge. If it is determined in S100 that the work area 60 has been set, the process proceeds to S101, and if it is determined that the work area 60 has not been set, the process proceeds to step S110.

In step S101, the controller 40 (working machine attitude calculation unit 72) receives data input from the working machine attitude detection device 51 (input of attitude information of the front working machine 1), , it is determined whether or not the front work implement 1A has reached full reach (maximum). If the reach of the front working machine 1A is determined to be the maximum, the process proceeds to step S102, and if the full reach is not reached, the process proceeds to step S105.

In step S102, the controller 40 (the target stop angle calculation unit 101) determines whether or not the front work implement 1A deviates from the work area 60 due to the turning motion in the full reach posture. That is, it is determined whether or not the hydraulic excavator 1 moves out of the work area 60 when turning at full reach. If it is determined that the vehicle will deviate, the process proceeds to step S103, and if it is determined that the vehicle will not deviate, the process proceeds to step S110.

In step S103, the controller 40 (target stop angle calculation unit 101) calculates a target stop angle θstop for not deviating from the work area 60 at the current working machine attitude (full reach). Specifically, the target stop angle calculator 101 calculates the rotation angles α, β, and γ of the boom 8, arm 9, and bucket 10, the distance d between the origin of the excavator reference coordinate system and the work area boundary 61, and the formula Based on (1)-(3), the target stop angle θstop at full reach is calculated, and it is output to the turn command calculation unit 104 . After step S104 is finished, the process proceeds to step S104.

In step S104, the controller 40 (swing braking behavior prediction unit 102) calculates the predicted swing braking angle, which is the angle required from the start of swing braking until the upper swing body 12 stops, at the current working machine posture (full reach). It calculates the angle θpre and outputs it to the turn command calculation unit 104 . Then go to step 108 .

In step S108, the controller 40 (swing command calculation unit 104) calculates the sum of the predicted swing braking angle θpre calculated in step S104 and the current angle θc input from the swing angle calculation unit 70 as the target calculated in step S103. It is determined whether or not the turning stop angle θstop has been reached. If the sum of these reaches the target turning stop angle θstop, the process proceeds to step S109, and if not, the process proceeds to step S110.

In step S109, the controller 40 (swing command calculation unit 104) executes swing braking control, that is, swing braking, thereby decelerating the swinging motion of the upper swing structure 12 and preventing deviation from the work area 60. .

In step S110, the swing braking control by the controller 40 is not executed, and the swing motion of the excavator 1 is performed according to the operator's operation. The processing of step S110 is performed when negative determinations are made in steps S100, S102, S106, and S108.

On the other hand, in step S105 (that is, when it is determined in step S101 that the front work implement 1A has not reached full reach), the controller 40 (turn braking behavior prediction unit 102) performs turn braking by turning braking control. The change in the reach Rpre of the front work implement 1A (predicted work implement reach) between the start and the stop of the upper revolving body 12, and the time required from the start of turning braking until the upper revolving body 12 stops. A predicted turning braking angle θpre, which is an angle, is calculated. Specifically, in the state of the attitude/speed of the front work equipment 1A and the angular velocity of the upper rotating body 12 at the present time (at the time of execution of step S105), swing braking and maximization of the reach of the work equipment are performed by a predetermined braking torque τ. Assuming that it has started, the angle (predicted swing braking angle) θpre required until the upper swing body 12 stops, and the change in the reach Rpre of the front work implement 1A until the upper swing structure 12 stops (predicted work implement reach) is calculated based on the equation of motion of the above equation (4). As described above, the maximization of the work implement reach in the present embodiment is performed by rotating the reach Rbk of the front work implement 1A shown in Equation (2) from the posture at the time of calculation (at the present time) so as to maximize the reach. The angles α, β, γ (the speed of each cylinder 5-7) are changed according to a predetermined rule. When the calculations of the predicted work equipment reach and the predicted swing braking angle θpre are completed, they are output to the target stop angle corrector 103 and the swing command calculator 104, and the process proceeds to step S106.

In step S106, the control controller 40 (target stop angle correction unit 103) determines when the hydraulic excavator 1 swings with the predicted working equipment reach calculated in step S105 (that is, while increasing the working equipment reach toward the maximum). , determines whether a part of the hydraulic excavator 1 deviates from the work area 60 or not. The determination can be made in the same manner as in step S102. If it is determined that the vehicle will deviate, the process proceeds to step S107, and if it is determined that the vehicle will not deviate, the process proceeds to step S110.

In step S107, the controller 40 (target stop angle correction unit 103) calculates the predicted work machine reach (changes in the rotation angles α, β, γ) calculated in step S105, the distance d, and the above equation (1)- From (3), a target turning stop angle (corrected turning stop angle θrs) for not deviating from the work area 60 is calculated. After that, the process proceeds to step S108.

When the process comes to step S108 via step S107, the controller 40 (swing command calculation unit 104) determines the predicted swing braking angle θpre calculated in step S105 and the current angle θc input from the swing angle calculation unit 70. It is determined whether or not the sum has reached the target turning stop angle (corrected turning stop angle θrs) calculated in step 107 . If the sum of these reaches the target swing stop angle (corrected swing stop angle θrs), the process proceeds to step S109 (that is, swing braking is executed), and if not, the process proceeds to step S110.

-effect-
The hydraulic excavator 1 configured as described above exhibits the following effects.

(1) When there is no possibility of deviating from the work area 60 even if the front work implement 1A is operated during swinging Even if the front work implement 1A is operated by the operator while the upper swing body 12 is swinging, the hydraulic excavator 1 does work. When there is no possibility of deviating from the region 60, that is, when it is determined as NO in any of steps S100, S102, and S106 and the process reaches step S110, the turning braking control is not executed, so unnecessary turning braking control ( It is possible to prevent a decrease in work efficiency due to avoidance of turning braking.

(2) When the front work equipment 1A is operated and deviates from the work area 60 during swinging. The target swing stop angle (corrected swing stop angle θrs) when the reach length of the front work implement 1A is increased toward the maximum value is calculated, and the upper swing body is calculated after the start of swing braking (swing braking control). The reach length and moment of inertia of the front work implement 1A are taken into consideration in calculating the predicted turning braking angle θpre, which is the angle required until the work implement 12 stops. With this configuration, it is possible to prevent deviation from the work area 60 while permitting the operator to operate the front work implement 1A during swing braking control. If the predicted turning braking angle θpre and the predicted reach of the work implement are calculated on the assumption that the front work implement 1A is always at full reach, the calculation is performed when S105, 106, and 107 are passed in this embodiment. Since it takes a large value compared to θpre and the predicted work equipment reach, the control result is conservative. However, in this embodiment, since the predicted work equipment reach and the predicted swing braking angle θpre are sequentially calculated based on the attitude of the front work equipment 1A at the current time, the swing braking control can be performed under reasonable conditions that can actually occur. can be executed.

Therefore, according to the present embodiment, even if the operator is allowed to operate the front work equipment 1A during the turning braking control, problems due to this may occur (for example, deviation from the work area 60, lack of operational feeling of the operator, etc.). decrease, etc.) can be prevented.

Note that the flowchart may be configured so that step S102 in FIG. 8 is executed after a YES determination is made in step S100, and step S101 is executed after a YES determination there. That is, in FIG. 8, the order of steps S101 and S102 can be interchanged. If steps S101 and S102 are interchanged, step S106 can be omitted.

As shown in FIG. 5, when the hydraulic excavator 1 is on a sloping ground, the turning motion is affected by gravity due to the inclination of the slope. In this case, the turning braking behavior prediction unit 102 shown in FIG. Considering the influence, it is possible to calculate Rpre, which is the predicted reach of the working machine during swing braking control, and θpre, which is the predicted swing braking angle. Specifically, the following equation of motion (equation (6)) is used, with G being the term of the influence of gravity (the term of the influence of gravity).

As a result, it is possible to accurately predict the behavior during turning braking control even when the vehicle is affected by gravity.

<Modification>
In the above-described first embodiment, regardless of whether the operator actually operates the front work implement 1A while the upper swing body 12 is swinging, the reach of the front work implement 1A tends to reach the maximum value by the operator's operation. Although the turning braking has been described assuming a situation in which the force increases, the operator's operation may be considered in the following manner.

(1) When the operator does not touch the operation right lever 22a The hydraulic excavator 1 according to the first embodiment, as shown in FIG. An operation right lever 22a capable of operating the boom 8 and the bucket 10, which are two front members of the bucket 10), and an arm 9, which is the remaining one front member excluding the two front members from the three front members. An operation left lever 22b capable of operating the upper revolving body 12 is provided. When the upper swing body 12 swings, the operator normally inputs a swing operation with the left hand via the operation left lever 22b, and when it is necessary to operate the front work machine 1A, other operations are performed in addition to this swing operation. input. Therefore, if the operator does not touch the right operation lever 22a during the turning operation by the left operation lever 22b, the boom 8 and the bucket 10 do not operate. Therefore, a contact detection sensor capable of detecting whether or not the operator is touching the right operation lever 22a is attached to the right operation lever 22a. You may change the calculation content of angle (theta)pre. Specifically, when it is determined that the operator is touching the operation right lever 22a, the predicted working machine reach and the predicted turning braking angle θpre are calculated based on the processing already explained in step S105 of FIG. (i.e., the calculation is performed assuming that the working equipment reach is maximized).On the contrary, when it is determined that the operator has not touched the operation right lever 22a, the posture of the front working equipment 1A at that time is changed to the boom 8 and the bucket 10 do not operate, and the flowchart may be changed so as to calculate the predicted reach of the work implement and the predicted turning braking angle θpre assuming that the reach of the work implement increases only by the pushing motion of the arm 9 (that is, The work equipment reach is calculated assuming that it increases only with the arm dump operation).

(2) When the operation levers 22a and 22b are operated in the direction of decreasing the reach of the work equipment When the front work equipment 1A is operated in the direction of reducing the reach of the work equipment by the operation of the operation levers 22a and 22b by the operator, Considering the delay time that occurs from the time when the operator reverses the operating direction to the direction in which the reach of the work equipment is extended and until the actuator actually moves in the opposite direction, the time from start to stop of swing braking shown in step S105 in Fig. 8 is predicted. A step of calculating the work implement reach and the predicted turning braking angle θpre may be calculated. For example, when the left operation lever 22b is operated by the operator in the winding direction of the arm 9 (the direction in which the arm cylinder 6 extends), the actuator moves in the opposite direction, that is, in the direction in which the arm 9 extends (the arm cylinder 6 contracts). The calculation of step S105 may be performed in consideration of the delay required until it moves in the direction of movement).

(3) Summary (Fig. 12, Fig. 14)
Here, a hydraulic excavator according to a modified example of the first embodiment reflecting the above (1) and (2) will be described. FIG. 14 is a functional block diagram of a hydraulic excavator controller 40 according to this modification. The contact detection sensor 58 shown in FIG. 14 is a sensor for detecting whether or not the operator is touching the right operation lever 22a, and is attached to the right operation lever 22a. The contact detection sensor 58 is electrically connected to the controller 40 , and the detection signal of the contact detection sensor 58 is output to the turning braking behavior prediction section 102 in the controller 40 .

FIG. 12 shows a part of the flowchart of the processing executed by the controller 40 shown in FIG. It has become. The processing up to steps S1051 to S1057 in FIG. 12 is processing that substitutes for step S105 in FIG. 8 is completed, the process returns to step S106 in FIG. 8, and other processes are the same as in FIG.

First, in step S1051, the controller 40 (swing braking behavior prediction unit 102) determines based on the signal from the contact detection sensor 58 whether or not the operator is touching the operation right lever 22a. If it is determined that the operator is touching the operation right lever 22a, the process proceeds to step S1052.

In step S1052, based on the signal from the operator operation detection device 53, the controller 40 (swing braking behavior prediction unit 102) operates the operation right lever 22a and the operation left lever 22b to reduce the reach of the front work implement 1A. is operated. If it is determined that the front work implement 1A is operated in the contracting direction by the operation right lever 22a and the operation left lever 22b, the process proceeds to step S1053.

In step S1053, the controller 40 (swing braking behavior prediction unit 102) starts and stops swing braking after considering the delay time until the actuator operated in the contraction direction moves in the opposite direction (extending direction). The predictive work implement reach and the predictive turning braking angle θpre are calculated until the vehicle is reached. That is, the predicted reach of the work implement and the predicted turning braking angle θpre are calculated on the assumption that the reach of the work implement increases toward the maximum value after the elapse of the delay time.

If it is determined in step S1052 that the retraction direction has not been performed, the process proceeds to step S1054, and the controller 40 (swing braking behavior prediction unit 102) performs the same processing as step S105 in FIG. 8, that is, starts swing braking. A predicted working machine reach and a predicted turning braking angle θpre until the machine stops are calculated.

On the other hand, if it is determined in step S1051 that the operation right lever 22a has not been touched, the process proceeds to step S1055.

In step S1055, the controller 40 (swing braking behavior prediction unit 102) determines whether or not the left operation lever 22b is being operated in the direction in which the arm 9 is retracted, based on the signal from the operator operation detection device 53. If it is determined that the operation is in the contracting direction, the process proceeds to step S1056.

In step S1056, the controller 40 (swing braking behavior prediction unit 102) assumes that the boom 8 and bucket 10 do not move, and considers the delay until the arm 9 operated in the retracting direction moves in the opposite direction (extending direction). Then, the predictive work equipment reach and the predictive swing braking angle θpre from the start to stop of swing braking are calculated. In other words, it is assumed that after the delay time has elapsed, the work equipment reach increases toward the maximum value only by the operation of the arm 9 (however, the maximum value only by the arm operation while the boom 8 and the bucket 10 are kept in the same posture). Assuming, the predicted working machine reach and the predicted turning braking angle θpre are calculated.

If it is determined in step S1055 that the operation has not been performed in the retraction direction, the process proceeds to step S1057.

In step S1057, the controller 40 (swing braking behavior prediction unit 102) assumes that the boom 8 and bucket 10 do not move, and calculates the predicted work machine reach and the predicted swing braking angle θpre from when swing braking is started to when it stops. That is, assuming that the work machine reach increases toward the maximum value only by the operation of the arm 9 (however, the maximum value only by the arm operation while the boom 8 and the bucket 10 are kept in the same posture), the predicted work machine reach A reach and a predicted turning braking angle θpre are calculated.

In this way, by replacing step S105 in the flowchart of FIG. 8 with steps S1051-1057 shown in FIG. 12, it is possible to prevent the predicted reach of the work equipment and the predicted turning braking angle θpre from being excessively predicted. The work efficiency and the operator's operational feeling can be improved compared to conventional systems.

<Second embodiment>
In the present embodiment, swing braking control will be described in a situation where the upper swing body 12, not the front work implement 1A, may deviate from the work area 60 due to swing motion. Here, as shown in FIG. 7, an example of turning braking control when there is a risk that the left rear end portion 12BL of the upper turning body 12 may deviate from the work area 60 due to turning operation (right turning) is shown. Note that the description of the parts common to the first embodiment may be omitted.

In FIG. 7, Lus is the length from the turning center 120 to the left rear end 12BL, and α _us is the angle from the longitudinal direction of the front working machine (which coincides with the X axis when the turning angle is zero) to the left rear end 12BL. Then, the Y-axis position Yus of the left rear end portion 12BL of the upper swing body 12 with respect to the swing center 120 is expressed by the following equation (7).

At this time, assuming that the distance between the turning center 120 and the work area boundary 61 is d, the target turning stop angle θusstop is expressed by the following equation (8).

In the present embodiment, the turning braking behavior prediction unit 102 adjusts the posture of the front work implement 1A so that the moment of inertia term J in equation (4) (or equation (6)) continues to increase from the current point toward the maximum value. The turning braking angle θpre is calculated on the assumption that it will be changed from the current time. As can be seen from Equation (4) (or Equation (6)), the positional relationship between the rear end portion of the upper rotating body 12 and the work area boundary 61 is not affected by the posture of the front work implement 1A. On the other hand, the turning braking angle θpre is affected by the moment of inertia term J that depends on the attitude of the front work implement 1A. Therefore, in order to prevent the upper swing body 12 from deviating from the work area 60 due to the swing motion as in the present embodiment, the effect of the moment of inertia term J should be considered. A flow chart for this case is shown in FIG. It should be noted that the correlation diagram shown in FIG. 11 can also be used to calculate the change in the attitude of the front work implement 1A of the present embodiment, as in the first embodiment.

FIG. 9 shows a flowchart of departure prevention control executed by the controller 40 of this embodiment. The controller 40 starts the flow of FIG. 9 when the operator performs a turning operation with the operation lever 22b. However, during turning, the flow of FIG. 9 is repeatedly executed at a predetermined cycle. Note that the same processing (steps) as those in FIG. 8 are denoted by the same reference numerals, and description thereof may be omitted.

In step S200, the controller 40 (the target stop angle calculation unit 101) determines whether or not the rear end of the upper swing body 12 deviates from the work area 60 due to the swing motion. If it is determined that the vehicle will deviate, the process proceeds to step S201, and if it is determined that the vehicle will not deviate, the process proceeds to step S110.

In step S201, the controller 40 (target stop angle calculator 101) calculates the target turning stop angle θusstop using the above equation ( 8 ). After that, the process proceeds to step S202.

In step S202, the controller 40 (swing braking behavior prediction unit 102) determines whether or not the moment of inertia J determined by the attitude of the front work implement 1A is maximum at the present time (at the time of calculation in step S202). The maximum value of the moment of inertia J is calculated in advance, and here, it is determined whether or not the moment of inertia J at the present moment has reached the maximum value. If J is the maximum at this time, the process proceeds to step S104, and if not, the process proceeds to step S203.

In step S104, the controller 40 (swing braking behavior prediction unit 102) starts swing braking while maintaining the current work machine posture (that is, while the moment of inertia J is maximized), and then the upper structure 12 stops. Predicted turn braking angle θpre, which is an angle required until the turn is reached, is calculated and output to turn command calculation unit 104 . Then go to step 108 .

In step S203, the controller 40 (swing braking behavior prediction unit 102) makes a prediction on the assumption that the attitude of the front work implement 1A changes so that the moment of inertia J continues to increase toward the maximum value during the braking period. A turning braking angle θpre is calculated, and then the process proceeds to step S108.

Since the processes of steps S100, S108, S109, and S110 are the same as those of the first embodiment, description thereof is omitted.

In this embodiment, unlike the first embodiment, the work area 60 at the rear end of the upper swing body 12 is subject to deviation prevention control, so the target swing stop angle θusstop does not change depending on the attitude of the front work implement 1A. Therefore, the step of predicting the behavior during turning braking control and changing the target turning stop angle θusstop (step S107 in FIG. 8) is unnecessary and is not performed.

Further, by combining the present embodiment and the first embodiment, it is determined which of the front work implement 1A and the upper swing body 12 is more likely to deviate from the work area 60, and A configuration may be adopted in which the swing braking control is performed with priority given to a swing structure 12 that is highly likely to deviate from the work area 60 . That is, if the front work implement 1A is more likely to deviate, the flowchart of FIG. 8 is executed to determine the timing for outputting the rotation stop command. 9 is executed to determine the timing for outputting the rotation stop command. As for the determination of the degree of possibility of deviation, for example, it can be determined that the possibility of deviation is higher in the direction in which the target turning stop angle is reached first in step S108.

<Third Embodiment>
By the way, the weight of the cargo in the bucket 10 affects the moment of inertia J. Therefore, in this embodiment, the weight (load) of the cargo in the bucket 10 is calculated, and the moment of inertia J calculated based on the load value is used to determine the movement of the upper swing body 12 and the front working machine 1A during the braking period. will be described. Descriptions of parts common to the first embodiment are omitted.

FIG. 10 is a functional block diagram of the hydraulic excavator controller 40 according to this embodiment. A load calculator 105 is added to the functional block diagram of the first embodiment shown in FIG.

The load calculator 105 is connected to the cylinder pressure detector 57 . The cylinder pressure detection device 57 is composed of pressure sensors provided on the rod portion and the bottom portion of the boom cylinder 5 . The load calculation unit 105 calculates the load of the load on the bucket 10 from the attitude of the front working machine 1A and the differential pressure between the rod portion and the bottom portion of the boom cylinder 5 from the cylinder pressure detection device 57 .

The turning braking behavior prediction unit 102 calculates the moment of inertia term J shown in the above formula (4) (or formula (6)) based on the load calculation result of the load calculation unit 105 . Further, based on this, as in the first embodiment, Rpre, which is the predicted reach of the working machine during swing braking control, and θpre, which is the predicted swing braking angle, are calculated.

For example, when there is a load on the bucket 10, the moment of inertia is increased by the load of the load and the braking distance is longer than when the bucket 10 is in the same posture without the load. By considering the load of the bucket, it is possible to accurately estimate the predicted turning braking angle θpre, and to more reliably prevent deviation from the work area 60 .

In each of the embodiments shown so far, the configuration has been described as an example of a working machine (hydraulic excavator) equipped with a hydraulic lever that outputs pilot pressure according to the operation of the operating lever 22 by the operator. The present invention can also be applied to a working machine having an electric lever that outputs an electric signal in response to lever operation. In addition, although the tip of the bucket 10 has been described as an example of the reach, if a portion other than the tip of the bucket 10 (for example, the rear end of the bucket 10, the rod side tip of the bucket cylinder 7, etc.) has the maximum reach , the target turning stop angle θstop may be calculated from a portion other than the tip of the bucket 10 .

Further, although the detailed description is omitted in the above description, it is also possible to display on the screen of the display device 83 that the turning braking control is being executed and notify the operator.

It should be noted that the present invention is not limited to the above-described embodiments, and includes various modifications within the scope of the gist of the present invention. For example, the present invention is not limited to those having all the configurations described in the above embodiments, but also includes those with some of the configurations omitted. Also, it is possible to add or replace part of the configuration according to one embodiment with the configuration according to another embodiment.

In addition, each configuration related to the above-mentioned control device (control controller 40), the function and execution processing of each configuration, etc. are partly or wholly hardware (for example, the logic that executes each function is designed in an integrated circuit). etc.). Further, the configuration related to the above control device may be a program (software) that realizes each function related to the configuration of the control device by being read and executed by an arithmetic processing unit (for example, CPU). Information related to the program can be stored, for example, in a semiconductor memory (flash memory, SSD, etc.), a magnetic storage device (hard disk drive, etc.), a recording medium (magnetic disk, optical disk, etc.), or the like.

In addition, in the description of each of the above embodiments, the control lines and information lines have been shown as necessary for the description of the embodiments, but not necessarily all the control lines and information lines related to the product does not necessarily indicate In reality, it can be considered that almost all configurations are interconnected.

DESCRIPTION OF SYMBOLS 1A...Front working machine (working machine), 1B...Car body, 8...Boom, 9...Arm, 10...Bucket (attachment), 12...Upper revolving body, 33...Vehicle inclination angle sensor, 40...Control controller (control device) , 60 -- work area, θstop, θusstop -- target swing stop angle, θpre -- predicted swing braking angle, θrs -- corrected swing stop angle, Rpre -- reach of front working machine (reach length of working machine), 22a -- operation right lever (first operating lever), 22b... Left operating lever (second operating lever), 58... Contact detection sensor (sensor)

Claims (8)

a lower running body;
an upper rotating body rotatably attached to the lower traveling body;
a work machine attached to the upper revolving body;
Stops the swinging of the upper swing body before the upper swing body and the work machine deviate from the work zone based on the preset position of the work area and the attitudes of the upper swing body and the work machine. a control device that calculates a target swing stop angle, which is a target value of the swing angle for the purpose, and outputs a swing stop command for stopping the upper swing structure during swing at the target swing stop angle ，
The control device is
It is a period from when the rotation stop command is output to when the upper rotating body stops, assuming that rotation braking by a predetermined braking torque and maximization of the reach length of the work equipment have started. The predicted swing braking angle, which is the angle at which the upper swing body swings during the braking period, and the predicted work machine reach, which is the change in the reach length of the work machine until the upper swing body stops, are used for the work machine. calculated based on the attitude and speed of the upper rotating body and the turning angular velocity of the upper rotating body,
determining whether or not a part of the work machine deviates from the work area when the upper revolving body is turned by the predicted work machine reach;
When it is determined that a part of the work machine deviates from the work area, the target swing stop angle is set based on the predicted reach of the work machine and the distance d between the upper rotating body and the boundary of the work area. correct,
A working machine, wherein the turning stop command is output at a timing determined based on the predicted turning braking angle and the corrected target turning stopping angle. a lower running body;
an upper rotating body rotatably attached to the lower traveling body;
a work machine attached to the upper revolving body;
Stops the swinging of the upper swing body before the upper swing body and the work machine deviate from the work zone based on the preset position of the work area and the attitudes of the upper swing body and the work machine. a control device that calculates a target swing stop angle, which is a target value of the swing angle for the purpose, and outputs a swing stop command for stopping the upper swing structure during swing at the target swing stop angle ，
The control device is
determining whether or not the upper revolving structure deviates from the work area when the upper revolving structure is revolved;
When it is determined that the upper revolving structure deviates from the work area, the distance d between the upper revolving structure and the boundary of the work area The target turning stop angle is calculated based on the length Lus to the turning center of the turning body and the angle αus from the longitudinal direction of the work machine to the portion of the upper turning body determined to deviate from the work area. death,
The attitude of the work machine is changed so that the moment of inertia continues to increase toward the maximum value during the braking period, which is the period from when the rotation stop command is output until when the upper rotating body stops. Assuming that, calculating a predicted turning braking angle that is the angle at which the upper turning body turns during the braking period,
A working machine, wherein the rotation stop command is output at a timing determined based on the predicted rotation braking angle and the target rotation stop angle. In the working machine according to claim 1 or 2 ,
A working machine, wherein the control device predicts the operation of the working machine during the braking period based on the speed characteristics of an actuator that drives the working machine. The working machine according to claim 1,
The control device is
determining whether or not the upper revolving body deviates from the work area when the upper revolving body is revolved;
When it is determined that the upper revolving structure deviates from the work area, the distance d between the upper revolving structure and the boundary of the work area A first target turning stop angle is determined based on the length Lus to the turning center of the turning body and the angle αus from the longitudinal direction of the work machine to the portion of the upper turning body determined to deviate from the work area. and
A first prediction that is the angle at which the upper swing structure swings during the braking period, assuming that the posture of the work machine changes so that the moment of inertia continues to increase toward the maximum value during the braking period. Calculate the turning braking angle,
The earlier of the timing determined based on the first predicted turning braking angle and the first target turning stop angle and the timing determined based on the predicted turning braking angle and the corrected target turning stopping angle A working machine characterized by outputting the rotation stop command at the timing of . The working machine according to claim 1 ,
The control device considers the delay time until the work machine moves in the direction in which the reach length of the work machine extends when the work machine is operated in the direction in which the reach length of the work machine shrinks. A working machine, wherein the predicted turning braking angle is calculated. The working machine according to claim 1 ,
The working machine is a multi-joint working machine in which three members of a boom, an arm and an attachment are connected,
a first operating lever capable of operating two of the three members;
a second operating lever capable of operating one of the three members excluding the two members and the upper revolving body;
a sensor for detecting whether the operator is touching the first control lever;
When the sensor detects that the operator is not touching the first operating lever, the control device controls the reach of the work machine by the remaining one member without operating the two members during the braking period. A working machine characterized in that the predicted turning braking angle is calculated on the assumption that the length will increase. The working machine according to claim 1,
the work machine includes a bucket;
The control device calculates the moment of inertia of the upper swing body based on the load of the cargo in the bucket, and uses the moment of inertia to predict the motion of the upper swing body and the work machine during the braking period. A working machine characterized by: The working machine according to claim 1,
The control device is characterized in that, based on the vehicle body inclination angle of the upper revolving body, including an influence term of gravity due to the vehicle body inclination, the operation of the upper revolving body and the work implement during the braking period is predicted. working machine.

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