Brake control system

Abstract

To prevent an actual stop position of an object moved by an actuator from exceeding a target stop position.SOLUTION: A brake control system 1 includes an actuator 30, an object OB moved by the actuator 30, and a controller 70. A stop position which is a target of the object OB is defined as a target stop position Ps. A position where the object OB is stoppable when the actuator 30 applies a brake with a specific brake amount is defined as a stoppable position Pp. When it is determined that a difference between the target stop position Ps and the stoppable position Pp is equal to or less than a threshold, the controller 70 performs specific brake amount control, which is control of causing the actuator 30 to apply a brake with the specific brake amount.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a brake control system that controls a brake of a working machine.

Background Art

[0002] For example, Patent Document 1 describes a technique in which the movement of a working machine is controlled based on a work plan.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a work plan, it is targeted that an actuator applies a brake and stops an object (target object) moved by the actuator at a target position (target stop position). However, when the actuator applies a brake with a certain brake amount (for example, the maximum brake amount of the actuator), the object may not be able to stop at the target stop position and may exceed the target stop position (overrun).

[0005] Therefore, an object of the present invention is to provide a brake control system that can suppress the actual stop position of an object moved by an actuator from exceeding the target stop position.

Means for Solving the Problems

[0006] The brake control system includes an actuator, an object, and a controller. The actuator is mounted on a working machine. The object is moved by the actuator. The controller controls the actuator. The target stop position of the object is defined as the target stopping position. The position where the object can stop when the actuator applies a brake with a specific brake amount is defined as the stoppable position. When the controller determines that the difference between the target stopping position and the stoppable position is equal to or less than a threshold value, the controller performs specific brake amount control. The specific brake amount control is control for causing the actuator to apply a brake with the specific brake amount.

Effect of the Invention

[0007] With the above brake control system, it is possible to suppress the actual stop position of the object moved by the actuator from exceeding the target stop position.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] The brake control system 1 will be described with reference to FIGS. 1 to 6.

[0010] The brake control system 1 is a system that controls the brake of the actuator 30 of the working machine 10 (object OB) shown in FIG. 1. The brake control system 1 includes the working machine 10, a detection unit 40 (see FIG. 3), an input unit 60, a controller 70, and an output unit 80.

[0011] The working machine 10 (object OB) is a machine that performs work. The working machine 10 is, for example, a construction machine that performs construction work. The working machine 10 may be an excavator or a crane. Hereinafter, mainly the case where the working machine 10 is an excavator will be described. The working machine 10 is configured to be operable by automatic control. The automatic control may be automatic operation or semi-automatic operation (machine control described later). The working machine 10 may operate in response to an operation by an operator without using automatic control. For example, the working machine 10 may be operated by an operator in the cab 13c (described later), or may be remotely operated from outside the working machine 10. The working machine 10 includes a machine body 10a, an attachment 15, a drive control unit 17 (see FIG. 3), and an actuator 30.

[0012] The machine body 10a is the main body part of the working machine 10. The machine body 10a includes a lower body 11 and an upper slewing body 13.

[0013] The lower body 11 rotatably supports the upper slewing body 13. The lower body 11 may be a lower traveling body capable of traveling on a traveling surface (such as the ground). When the lower body 11 is capable of traveling, the lower body 11 may include crawlers or wheels.

[0014] The upper slewing body 13 is rotatably mounted on the lower body 11. The upper slewing body 13 includes a cab 13c. The cab 13c is a part where an operator can operate the working machine 10.

[0015] The attachment 15 is the part where work is performed. The attachment 15 is attached to the machine body 10a. For example, the attachment 15 includes a boom 15a, an arm 15b, a tip attachment 15c, and a specific part 15s. The boom 15a is rotatably (capable of tilting, rotating in the front-rear direction and the up-down direction) attached to the upper slewing body 13. The arm 15b is rotatably (rotating in the front-rear direction and the up-down direction) attached to the boom 15a.

[0016] The tip attachment 15c is provided at the tip of the attachment 15. The tip attachment 15c is rotatably (rotating in the front-rear direction and the up-down direction) attached to the arm 15b. The tip attachment 15c may be a bucket capable of performing operations such as scooping up captured objects and excavation. The tip attachment 15c may also be a device for clamping captured objects (such as a grapple or a nibbler), a device for crushing captured objects (such as a breaker), or a magnet for adsorbing metal captured objects. The captured object captured by the tip attachment 15c is the object to be the target of the work of the working machine 10. The captured object may be earth and sand, stone, wood, metal, resin, waste, or a structure (such as a block).

[0017] The specific part 15s is a part that is targeted to be arranged on the target path PA (see FIG. 2) described later. The specific part 15s is a specific part of the attachment 15. For example, the specific part 15s may be the tip of the tip attachment 15c or the base end of the tip attachment 15c (the tip of the arm 15b).

[0018] The drive control unit 17 (see FIG. 3) controls the actuator 30. The drive control unit 17 may include a hydraulic circuit that controls the actuator 30 (hydraulic actuator) that moves by hydraulic pressure. This hydraulic circuit is configured to be able to control the flow rate of the hydraulic oil supplied to each hydraulic actuator according to the target speed of each hydraulic actuator. This hydraulic circuit is configured to be able to shunt-control the flow rate of the hydraulic oil discharged by the hydraulic pump according to the target speed of each hydraulic actuator. The drive control unit 17 may include an electric circuit that controls the actuator 30 (electric actuator) that moves by electric power. This electric circuit is configured to be able to supply electric power to each electric actuator according to the target speed of each electric actuator.

[0019] The actuator 30 is a device that moves each part of the work machine 10. The object moved by the actuator 30 is defined as the object OB. The object OB is part or all of the work machine 10. The actuator 30 may include a hydraulic actuator or an electric actuator. The actuator 30 may include a motor that rotates or a cylinder (extension cylinder) that drives in extension and contraction. The actuator 30 includes a travel motor 31, a swing motor 33, a boom cylinder 35a, an arm cylinder 35b, and a tip attachment cylinder 35c.

[0020] The traveling motor 31 drives the lower body 11 to travel, for example, to drive crawlers. When the lower body 11 is provided with left and right crawlers, a traveling motor 31 for driving the left crawler and a traveling motor 31 for driving the right crawler are provided. The traveling motor 31 may be, for example, a hydraulic motor or an electric motor (the same applies to the slewing motor 33). The slewing motor 33 slews the upper slewing body 13 with respect to the lower body 11. The boom cylinder 35a rotates (rises and falls) the boom 15a with respect to the upper slewing body 13. The boom cylinder 35a is, for example, a hydraulic cylinder (the same applies to the arm cylinder 35b and the tip attachment cylinder 35c). The arm cylinder 35b rotates the arm 15b with respect to the boom 15a. The tip attachment cylinder 35c rotates the tip attachment 15c with respect to the arm 15b. When the tip attachment 15c itself is drivable, for example, like a device for gripping an object, an actuator 30 for driving the tip attachment 15c may be provided.

[0021] The detection unit 40 detects various states. Part or all of the detection unit 40 may be mounted on the working machine 10 or may be arranged outside the working machine 10. The same applies to the input unit 60, the controller 70, and the output unit 80, which will be described later, in that they may be mounted on the working machine 10 or may be arranged outside the working machine 10. The detection unit 40 includes a position detection unit 41, an imaging device 43, and an attitude detection unit 50.

[0022] The position detection unit 41 detects the position of the object to be measured. The position detection unit 41 detects the position of a specific part of the working machine 10. For example, the position detection unit 41 may detect the position of a specific part of the upper swing body 13, or may detect the position of a specific part of the attachment 15. The position detection unit 41 may detect the position using electromagnetic waves (such as light and radio waves). The position detection unit 41 may use a satellite positioning system, for example, it may use GNSS (global navigation satellite system). The position detection unit 41 may also use a (ground-based) transmitter and receiver without using satellites, for example, it may use a total station. The position detection unit 41 may detect the direction (orientation) of the object to be measured (the detection unit 40 may include a direction detection unit). The position detection unit 41 may detect the azimuth of the object to be measured using geomagnetism. The position detection unit 41 may calculate the position and direction of the object to be measured based on the position information detected by multiple types of devices.

[0023] The imaging device 43 images an object to be imaged. The object to be imaged may include the working machine 10 or may include the surroundings of the working machine 10. The imaging device 43 may detect a two-dimensional image or may detect a three-dimensional image (distance image) having depth information. The imaging device 43 may be of a passive type or an active type. Specifically, the imaging device 43 may include a camera (monocular camera) that detects two-dimensional information. The imaging device 43 may include a stereo camera that detects three-dimensional information. The imaging device 43 may irradiate the object to be imaged with a wave such as an electromagnetic wave and detect the reflected wave to detect the three-dimensional information of the object to be imaged. The imaging device 43 may include a TOF (Time Of Flight) sensor that detects the distance based on the time from when the wave is irradiated until the reflected wave returns, or may include a sensor that detects the distance based on the frequency of the reflected wave. The imaging device 43 may include a device that detects three-dimensional information using light (for example, laser light), and may include, for example, LiDAR (Light Detection and Ranging). The imaging device 43 may include a device that detects three-dimensional information using radio waves (for example, a millimeter-wave radar, etc.). The imaging device 43 may detect the three-dimensional information of the object to be imaged based on the three-dimensional image (distance image) and the two-dimensional image.

[0024] The posture detection unit 50 detects the posture of the working machine 10. The posture detection unit 50 may include one type or a plurality of types of detection devices. The posture detection unit 50 may include a detection device (such as a rotary encoder) that detects information on the angle of another element with respect to a certain element of the working machine 10. The posture detection unit 50 may include a stroke sensor that detects the stroke of a cylinder (such as the boom cylinder 35a) that moves the attachment 15. The posture detection unit 50 may include an inclination sensor that detects the angle (inclination) with respect to the horizontal direction. The posture detection unit 50 may include a sensor (such as a gyro sensor) that detects the angular velocity with respect to the work site, and may also include a sensor that detects the acceleration with respect to the work site. The posture detection unit 50 may include an inertial measurement device or the like. The posture detection unit 50 may include the above-mentioned position detection unit 41. In this case, the posture detection unit 50 may detect the posture of the working machine 10 based on the position information detected by the position detection unit 41. The posture detection unit 50 may include the above-mentioned imaging device 43. The posture detection unit 50 may detect the posture of the working machine 10 based on the image recognition of a two-dimensional image. The posture detection unit 50 may detect the posture of the working machine 10 based on a three-dimensional image (distance image). The posture detection unit 50 may detect the posture of the working machine 10 based on the three-dimensional image and the two-dimensional image. The posture detection unit 50 includes a reference position detection unit 51, an inclination detection unit 52, a turning detection unit 53, a boom detection unit 55a, an arm detection unit 55b, and a tip attachment detection unit 55c.

[0025] The reference position detection unit 51 detects the position and orientation of the reference position (reference position) of the working machine 10 with respect to the work site. The reference position of the working machine 10 is, for example, a specific position of the upper slewing body 13 or the lower body 11. The reference position of the working machine 10 may be the attachment part (boom foot) of the boom 15a to the upper slewing body 13, or a specific position on the turning center axis of the upper slewing body 13 with respect to the lower body 11. The reference position detection unit 51 detects the position and orientation with respect to the work site based on information detected by, for example, the position detection unit 41 or the imaging device 43. In FIG. 1, the reference position detection unit 51 and the position detection unit 41 are marked with their symbols at the positions of the GNSS antennas in the case where detection is performed by a positioning system using GNSS.

[0026] The inclination detection unit 52 detects the inclination of the working machine 10 with respect to the horizontal direction. The inclination detection unit 52 may detect the inclination of the working machine 10 based on information detected by a device (such as a gyro sensor, an acceleration sensor, an inertial measurement device, etc.) that detects the inclination with respect to the horizontal direction. The inclination detection unit 52 may detect the inclination of the working machine 10 with respect to the horizontal direction based on information detected by, for example, the position detection unit 41 or the imaging device 43.

[0027] The turning detection unit 53 detects information (such as angle, angular velocity, angular acceleration, etc.) of the turning of the upper slewing body 13 with respect to the lower body 11. The turning detection unit 53 may detect the turning angle (turning angle) of the upper slewing body 13 with respect to the lower body 11 (it may also be a turning angle sensor), may detect the angular velocity (turning angular velocity), or may detect the angular acceleration (turning angular acceleration). The turning detection unit 53 may detect the turning information based on information detected by an angle sensor attached to the rotation axis or the rotation support part (such as a slewing bearing) of the upper slewing body 13 with respect to the lower body 11. The turning detection unit 53 may detect the turning information based on information detected by the position detection unit 41 or the imaging device 43.

[0028] The boom detection unit 55a detects the posture of the boom 15a. The boom detection unit 55a may detect the angle (inclination, rotation angle) of the boom 15a with respect to the horizontal direction or with respect to the upper swing body 13 (it may also be a boom angle sensor), may detect the rotational angular velocity, or may detect the rotational angular acceleration. The point that angles with respect to the horizontal direction or with respect to the components of the working machine 10 may be detected also applies to the arm detection unit 55b and the tip attachment detection unit 55c. The boom detection unit 55a may detect the posture of the boom 15a based on the information detected by the position detection unit 41, the imaging device 43, or the like.

[0029] The arm detection unit 55b detects the posture of the arm 15b. The tip attachment detection unit 55c detects the posture of the tip attachment 15c. Specific examples of the arm detection unit 55b and the tip attachment detection unit 55c are the same as the specific examples of the boom detection unit 55a.

[0030] The input unit 60 is a part (input device) for inputting information. The input unit 60 is operated by an operator and outputs a signal corresponding to the operation. The input unit 60 outputs information to the controller 70. The input unit 60 may be provided with a touch panel, may be provided with a mouse, may be provided with a keyboard, or may be provided with a switch. The input unit 60 may be provided on a tablet, may be provided on a smartphone, or may be provided on a personal computer. The input unit 60 may be provided on the working machine 10, for example, may be provided inside the cab 13c. The input unit 60 may be provided on a remote operation device for remotely operating the working machine 10. As shown in FIG. 3, the input unit 60 includes an operation unit 61 and an automatic control switch 63. Note that the input unit 60 may include a part for inputting information other than the operation unit 61 and the automatic control switch 63. Also, in FIGS. 3 and 6, the automatic control switch 63 is described as "Automatic Control SW".

[0031] The operation unit 61 is operated by the operator. Operations for moving the working machine 10 are input to the operation unit 61 shown in FIG. 3. The operation unit 61 may include a lever (operation lever) or may include a pedal (operation pedal).

[0032] The automatic control switch 63 is a part (automatic control selection unit) (for example, an automatic driving switch) that allows the operator to select whether to perform automatic control of the working machine 10. Details of the automatic control will be described later.

[0033] The controller 70 is a computer that performs signal input / output, calculation (processing), information storage, etc. The functions of the controller 70 are realized by a program stored in the storage unit of the controller 70 being executed by the calculation unit. The controller 70 and other devices may be connected by wireless communication or may be connected by wired communication. When there are a plurality of components of the controller 70, the components of the controller 70 may be connected by wireless communication or may be connected by wired communication. For example, information is input to the controller 70 from the detection unit 40 and the input unit 60. For example, the controller 70 performs various controls. Specifically, for example, the controller 70 controls the actuator 30 (see FIG. 1). Further, the controller 70 performs specific brake amount control and the like, which will be described later. For example, the controller 70 outputs a command (signal) for operating the working machine 10 to the drive control unit 17. As described above, the controller 70 may be mounted on the working machine 10 or may be arranged outside the working machine 10. The controller 70 may be distributed and arranged in a plurality of parts (may constitute a distributed system). The controller 70 includes an automatic control controller 71 and a vehicle body controller 73.

[0034] The automatic control controller 71 performs processes related to automatic control. For example, the automatic control controller 71 is an automatic driving controller that performs processes related to automatic driving. The automatic control controller 71 automatically controls the work machine 10 so that the work machine 10 moves according to a work plan (described later). The automatic control controller 71 outputs a command to the drive control unit 17 via the vehicle body controller 73 so that the work machine 10 moves according to the work plan. The automatic control controller 71 controls the movement of the work machine 10 based on the posture detected by the posture detection unit 50. Focusing on the functions of the automatic control controller 71, the automatic control controller 71 includes a detection information processing unit 71a, a work plan setting unit 71b, a work plan modification unit 71c, and a target command calculation unit 71d.

[0035] The detection information processing unit 71a receives information from the detection unit 40 and the input unit 60 (the automatic control switch 63 in the example shown in FIG. 3). The detection information processing unit 71a processes the input information.

[0036] The work plan setting unit 71b sets a work plan (described later).

[0037] The work plan modification unit 71c modifies the work plan. The work plan modification unit 71c (the vehicle body equipment specification work plan modification processing unit) performs a process of modifying the work plan based on, for example, the capabilities (specifications) of the equipment of the work machine 10. The work plan modification unit 71c performs the specific brake amount control described later.

[0038] The target command calculation unit 71d calculates a command to be output from the automatic control controller 71 to the vehicle body controller 73. The target command calculation unit 71d is, for example, a target speed command calculation unit that calculates a command for the target speed of the actuator 30. The target command calculation unit 71d outputs a command to the vehicle body controller 73.

[0039] The vehicle body controller 73 controls the movement of the work machine 10 and the like. Focusing on the functions of the vehicle body controller 73, the vehicle body controller 73 includes a target command processing unit 73a and a drive command calculation unit 73b.

[0040] The target command processing unit 73a receives the command output by the automatic control controller 71. The target command processing unit 73a processes the received command. For example, the target command processing unit 73a is a target speed command processing unit that processes a command for the target speed of the actuator 30.

[0041] The drive command calculation unit 73b calculates a command to be output to the drive control unit 17. For example, when the actuator 30 moves by hydraulic pressure, the drive command calculation unit 73b calculates a command for controlling a hydraulic circuit (an example of the drive control unit 17) that controls the actuator 30. Specifically, the drive command calculation unit 73b is a solenoid valve command calculation unit that calculates a command for the solenoid valve of the hydraulic circuit. For example, when the actuator 30 moves by electric power, the drive command calculation unit 73b calculates a command for controlling an electric circuit (an example of the drive control unit 17) that controls the actuator 30.

[0042] The output unit 80 is a device that outputs information. The output unit 80 outputs information based on the signal output from the controller 70. The output unit 80 outputs (notifies, instructs) information to the operator. The output unit 80 may output light (such as display), may output sound, or may output vibration. When the output unit 80 outputs light, the output unit 80 may include a device (monitor) for performing display (or may be a display unit). The output unit 80 may be provided on a tablet, may be provided on a smartphone, or may be provided on a personal computer. The output unit 80 may be provided, for example, in the cab 13c (see FIG. 1). The output unit 80 may be provided on a remote control device for remotely operating the work machine 10. For example, the output unit 80 may output the content of the work by the automatic control of the work machine 10. The output unit 80 may output information on specific brake amount control (described later).

[0043] (Operation) The brake control system 1 is configured to operate as follows.

[0044] (Operation of the work machine 10) As described above, the working machine 10 shown in FIG. 1 may be operated by an operator in the cab 13c, may be remotely operated by the operator from outside the working machine 10 (remote operation device), or may be automatically operated.

[0045] The working machine 10 is a machine that utilizes information and communication technology (ICT; Information and Communication Technology) (for example, ICT construction machinery).

[0046] For example, the working machine 10 may operate by machine control (MC; Machine Control system) (semi-automatic operation). Specifically, a work plan is set in the controller 70. Then, the operator operates only some elements of the attachment 15 (for example, only the boom 15a). At this time, the controller 70 automatically controls the elements that are not operated by the operator (for example, the arm 15b and the tip attachment 15c) so that the working machine 10 moves according to the work plan. At this time, the controller 70 controls the operation of the working machine 10 based on the information detected by the attitude detection unit 50 (the same applies to the case of automatic operation). As a result, the working machine 10 moves according to the work plan.

[0047] Also, for example, the working machine 10 may operate by automatic operation. In this case, the controller 70 controls the operation of the working machine 10 so that the working machine 10 automatically moves according to the work plan.

[0048] (Setting of work plan) The work plan setting unit 71b (see FIG. 3) sets the work plan of the working machine 10. The work plan is information regarding the work target of the working machine 10. The work plan may include information on the target movement of the attachment 15. The work plan may include information on the target travel of the working machine 10.

[0049] For example, as shown in FIG. 2, the work plan may include information on the target path PA of the specific part 15s of the attachment 15. The target path PA is information including, for example, information (coordinates) on the positions of a plurality of target points P (P1 to P5 in FIG. 2) and information on the order of each target point P. The work plan may include information on the target trajectory of the specific part 15s. The target trajectory is information obtained by adding time information to the information on the target path PA. This time information may be the time between two points or information on the time of day, etc. The time between two points is the target value of the movement time of the specific part 15s between two adjacent (consecutive in order) target points P. The information on the time of day is information such as the time when the specific part 15s reaches the target point P (target arrival time). By adjusting the time information, the target movement speed of the specific part 15s is adjusted.

[0050] For example, when the work machine 10 is traveling, the work plan may include information on the target path PA of a specific part of the work machine 10 (such as the above-mentioned "reference position", etc.), and may also include information on the target trajectory.

[0051] The parameters representing the position in the work plan can be set in various ways. Specifically, the parameters representing the position in the work plan are the parameters representing the target path PA, the target point P, and the target stop position Ps described later. The coordinate axes of the parameters representing the position in the work plan can be set in any way. The parameters representing the position in the work plan may be represented by coordinate axes (absolute coordinates) based on the work site. The parameters representing the position in the work plan may be represented by coordinate axes (machine coordinates) based on the work machine 10. For example, the origin of the machine coordinates may be set at the attachment part (boom foot pin) of the boom 15a to the upper swing body 13, or may be set at the swing center of the upper swing body 13 with respect to the lower body 11. Specifically, the work plan may include information on the front-rear direction, up-down direction, swing angle of the upper swing body 13 with respect to the lower body 11, and the angle (posture) of the tip attachment 15c, based on the upper swing body 13. The parameters representing the position in the work plan may include the position of the actuator 30 (see FIG. 1) that moves the work machine 10 (for example, the stroke position of the cylinder, the rotation angle of the motor, etc.).

[0052] The work plan may be set by the operator moving the work machine 10 (by teaching), or may be set by the operator operating the input unit 60 (by manual operation). The work plan may be automatically set by the controller 70. For example, the controller 70 may automatically set it based on the information detected by the detection unit 40 (such as obstacle information).

[0053] The work plan may be corrected before the specific brake amount control described later is performed. The work plan may be corrected by the operator operating the input unit 60 (by manual operation). The work plan may be automatically corrected by the controller 70 (for example, the work plan correction unit 71c) based on the information detected by the detection unit 40 (such as obstacle information).

[0054] Fig. 4 shows an example of the work plan information. In the example shown in Fig. 4, the horizontal axis represents the time in the work plan. In this example, the vertical axis represents the position of the target point P (target position). Specifically, the vertical axis represents the target angle of the turning angle of the upper revolving body 13 with respect to the lower main body 11 shown in Fig. 2. Note that the angle is included in the position. Similar to the turning angle, for parameters other than the turning angle, the relationship between the target position and time is set as the work plan.

[0055] (Overview of Specific Brake Amount Control) In the work plan, it is set as the goal that the object OB is moved to the actuator 30, decelerated, and stopped at the target stop position Ps. However, the brake amount required for the actuator 30 to stop the object OB at the target stop position Ps may exceed the specific brake amount of the actuator 30. In this case, even if the actuator 30 decelerates the object OB with the specific brake amount, the object OB will exceed the target stop position Ps (overrun).

[0056] Specifically, for example, the above "specific brake amount" is the maximum amount of brake that the actuator 30 can apply (full brake). In this case, when the brake amount required for the actuator 30 exceeds the full brake of the actuator 30, the object OB will exceed the target stop position Ps with the capabilities (performance, device specifications) of the actuator 30. Note that the specific brake amount does not have to be the full brake (described later).

[0057] Therefore, the controller 70 shown in FIG. 3 (for example, the work plan modification unit 71c, and the following controller 70 is the same unless otherwise specified) performs specific brake amount control. The specific brake amount control is control that suppresses the object OB shown in FIG. 2 from overrunning the target stop position Ps. The controller 70 (see FIG. 3) performs specific brake amount control when it determines that the difference between the target stop position Ps and the stoppable position Pp is equal to or less than the threshold value. Hereinafter, the target stop position Ps and the stoppable position Pp will be described, and the details of the comparison (determination) between them will be described. Hereinafter, the controller 70 and the components of the controller 70 will be described with reference to FIG. 3.

[0058] (Target stop position Ps) As shown in FIG. 2, the target stop position Ps is the target stop position of the object OB. The target stop position Ps is one of the target points P of the target path PA in the work plan.

[0059] As described above, the parameter representing the target stop position Ps can be set in various ways. Therefore, the controller 70 may convert (calculate, compute) the target stop position Ps that can be represented by various parameters and use it for processing (such as determination). For example, the controller 70 may calculate the target stop position Ps represented by coordinates (machine coordinates) based on the work machine 10 from the target stop position Ps represented by coordinates (absolute coordinates) based on the work site. Specifically, the controller 70 may calculate the target stop position Ps (target swing stop angle) of the swing angle of the upper swing body 13. For example, the controller 70 may calculate the travel distance (target travel stop distance) of the work machine 10 from a certain position to the target stop position as the target stop position Ps. Note that distances (such as travel distances) and amounts of movement are included in positions. Also, for example, the controller 70 may not perform the above calculations. For example, the controller 70 may use the target stop position Ps set in the work plan setting unit 71b as it is for processing (such as determination).

[0060] (Stoppable position Pp) The possible stop position Pp is the position where the object OB can stop when the actuator 30 applies a brake with a specific brake amount. The specific brake amount is an amount determined in advance (before the comparison between the target stop position Ps and the possible stop position Pp by the controller 70). The specific brake amount may be, for example, the maximum brake amount (full brake) that the actuator 30 can apply. The specific brake amount may be a specific brake amount that is approximately full brake. The specific brake amount may be a specific brake amount less than full brake (set value) that is neither approximately full brake nor full brake. The parameter representing the possible stop position Pp can be set in various ways, similar to the parameter representing the target stop position Ps. The controller 70 may convert (calculate) the possible stop position Pp represented by various parameters and use it for processing (such as determination).

[0061] (Determination) When the actuator 30 applies a brake with a specific brake amount, the controller 70 determines the possibility that the object OB exceeds (overruns) the target stop position Ps. Specifically, the controller 70 makes the following determination.

[0062] The controller 70 determines whether the difference between the target stop position Ps and the possible stop position Pp is less than or equal to a threshold value. Let [Condition α] be that the difference between the target stop position Ps and the possible stop position Pp is less than or equal to the threshold value. This "threshold value" may be 0 (the following [Condition α1]) or a value greater than 0. The threshold value is set based on the possibility that the object OB overruns from the target stop position Ps.

[0063] The controller 70 may determine whether the following [Condition α1] is satisfied. [Condition α1] is that the possible stop position Pp is equal to or exceeds the target stop position Ps. The above [Condition α1] is an example of the above [Condition α]. The case where the "threshold value" of the above [Condition α] is 0 is the above [Condition α1].

[0064] The controller 70 compares a parameter indicating the target stop position Ps (referred to as the target stop position Ps parameter) with a parameter indicating the stoppable position Pp (referred to as the stoppable position Pp parameter). Based on this comparison, the controller 70 determines whether the difference between the target stop position Ps and the stoppable position Pp is equal to or less than a threshold value (i.e., whether the above [Condition α] is satisfied).

[0065] Each of the target stop position Ps parameter and the stoppable position Pp parameter may be a position or a parameter convertible to a position. This "position" includes movement amounts such as a movement angle and a movement distance. The above "parameter convertible to a position" may be a time, a speed, or an acceleration. However, the target stop position Ps parameter and the stoppable position Pp parameter need to be comparable parameters. Specifically, if the target stop position Ps parameter is a time, the stoppable position Pp parameter is also a time.

[0066] (Types of Parameters and Details of Judgment) The target stop position Ps parameter and the stoppable position Pp parameter may be movement amounts. Specifically, the target stop position Ps parameter may be a target stop movement amount (for example, θ24 shown in FIG. 4). The target stop movement amount (θ24) is the movement amount (for example, movement distance, movement angle) of the object OB from the actual position A (for example, actual position A1) of the object OB to the target stop position Ps. The target stop movement amount (θ24) is the deviation (position deviation) of the actual position A with respect to the target stop position Ps. The actual position A is the actual position of the object OB and is the position detected by the detection unit 40 (see FIG. 3). Also, the stoppable position Pp parameter may be a stoppable movement amount. The stoppable movement amount is the movement amount (for example, movement distance, movement angle) of the object OB until the object OB stops when the actuator 30 applies a brake with a specific brake amount from the state of the actual position A and the actual speed of the object OB. The controller 70 determines that the above [Condition α] is satisfied when the difference between the target stop movement amount and the stoppable movement amount is equal to or less than a movement amount threshold (an example of the above "threshold"). The controller 70 determines that the above [Condition α] is not satisfied when the difference between the target stop movement amount and the stoppable movement amount exceeds the movement amount threshold. The movement amount threshold is, for example, 0. In this case, the controller 70 determines that the above [Condition α1] is satisfied when the stoppable movement amount is equal to or greater than the target stop movement amount (target stop movement amount ≦ stoppable movement amount). The controller 70 determines that the above [Condition α1] is not satisfied when the stoppable movement amount is less than the target stop movement amount (stoppable movement amount < target stop movement amount).

[0067] The target stop position Ps parameter and the stoppable position Pp parameter may be time. Specifically, the target stop position Ps parameter may be the target stop time (for example, Δt24 shown in FIG. 4). The target stop time (Δt24) is the target time in the work plan until the object OB moves from the actual position A (for example, the actual position A1) to the target stop position Ps and stops. Also, the stoppable position Pp parameter may be the stoppable time. The stoppable time is the time it takes for the object OB to stop at the target stop position Ps when the actuator 30 applies a brake with a specific braking amount from the state of the actual position A and the actual speed of the object OB. The controller 70 determines that the above [condition α] is satisfied when the difference between the target stop time and the stoppable time is equal to or less than a time threshold (an example of the above "threshold"). The controller 70 determines that the above [condition α] is not satisfied when the difference between the target stop time and the stoppable time exceeds the time threshold. The time threshold is, for example, 0. In this case, the controller 70 determines that the above [condition α1] is satisfied when the stoppable time is equal to or greater than the target stop time (target stop time ≦ stoppable time). The controller 70 determines that the above condition [condition α1] is not satisfied when the stoppable time is less than the target stop time (stoppable time < target stop time).

[0068] The target stop position Ps parameter and the stoppable position Pp parameter may be accelerations (deceleration when the actuator 30 applies a brake). Specifically, the target stop position Ps parameter may be a target stop acceleration. The target stop acceleration is the "certain acceleration" when it is assumed that the object OB decelerates at a certain acceleration from the actual position A to the target stop position Ps and then stops. The stoppable position Pp parameter may be a stoppable acceleration. The stoppable acceleration is the acceleration of the object OB (e.g., acceleration at full brake) when the actuator 30 applies a specific brake amount (e.g., full brake). The controller 70 determines that the above [Condition α] is satisfied when the difference between the target stop acceleration and the stoppable acceleration is equal to or less than an acceleration threshold (an example of the above "threshold"). The controller 70 determines that the above [Condition α] is not satisfied when the difference between the target stop acceleration and the stoppable acceleration exceeds the acceleration threshold. The acceleration threshold is, for example, 0. In this case, the controller 70 determines that the above [Condition α1] is satisfied when the magnitude of the target stop acceleration is equal to or greater than the magnitude of the stoppable acceleration (|stoppable acceleration| ≦ |target stop acceleration|) (e.g., when a brake stronger than the strength of full brake is required). The controller 70 determines that the above [Condition α1] is not satisfied when the magnitude of the target stop acceleration is less than the stoppable acceleration (|target stop acceleration| < |stoppable acceleration|) (e.g., when a brake less than the strength of full brake is required).

[0069] Note that as long as the controller 70 can determine whether or not the above [Condition α] is satisfied, any type of parameter can be used for the comparison between the target stop position Ps parameter and the stoppable position Pp parameter.

[0070] (Example of obtaining the target stop position Ps parameter) The controller 70 obtains (e.g., calculates) the target stop position Ps parameter as follows, for example. Here, a case where the target stop time is obtained is described as an example of the target stop position Ps parameter.

[0071] As described above, the target stop time (Δt24 in FIG. 4) is the target time in the work plan from when the object OB moves from the actual position A (e.g., actual position A1) to the target stop position Ps and stops. Therefore, the controller 70 acquires the actual position A1 of the object OB based on the information detected by the detection unit 40 (see FIG. 3). The controller 70 acquires the target stop position Ps (e.g., turning stop angle, traveling stop position) from the work plan. Then, the controller 70 may acquire the time interval (Δt24) from the actual position A1 to the target stop position Ps in the work plan shown in FIG. 4, and use this time interval (Δt24) as the target stop time.

[0072] Here, there may be an interval (e.g., Δθ23, Δθ34, etc.) between the positions of the target points P with consecutive order. Therefore, a case where the actual position A is deviated from the target point P (e.g., refer to the actual position A2 between the target points P2 and P3) is conceivable. In this case, for example, the controller 70 may use the time interval (e.g., Δt24) from the target point P closest to the actual position A2 (target point P2 in the example of FIG. 4) to the target stop position Ps as the target stop time. Also, for example, the controller 70 may use the time interval (e.g., Δt34) from the next target point P of the actual position A2 (target point P3 in the example of FIG. 4) to the target stop position Ps as the target stop time. Also, for example, the controller 70 calculates the time interval (ΔtA3 + Δt34) from the actual position A2 to the target stop position Ps based on the relationship between the positions of the target points P (target points P2 and P3 in this example) before and after the actual position A2 and the target time (the relationship shown in FIG. 4). Then, the controller 70 may use this time interval (ΔtA3 + Δt34) as the target stop time.

[0073] The controller 70 may calculate a target stop time based on the target speed at the actual position A. For example, the controller 70 may calculate the above time interval (ΔtA3 + Δt34) based on the target speed at the actual position A2 as follows. The controller 70 obtains from the work plan the time interval (Δt23) and the position deviation (Δθ23) (such as an angular difference, distance, etc.) between the target points P (in this example, target point P2 and target point P3) before and after the actual position A2. The controller 70 sets the value obtained by dividing this position deviation (Δθ23) by the time interval (Δt23) as the target speed (Δθ23 / Δt23) at the actual position A2. In addition, when the value of the target speed is directly set in the work plan at the actual position A2 or between the target points P before and after the actual position A2, the controller 70 may use the target speed obtained from the work plan as the target speed (Δθ23 / Δt23) at the actual position A2. Then, the controller 70 sets the value obtained by dividing the position deviation (ΔθA3) from the actual position A2 to the next target point P (target point P3) by the target speed (Δθ23 / Δt23) at the actual position A2 as the time interval (ΔtA3) from the actual position A2 to the next target point P (target point P3). And the controller 70 may use the sum (ΔtA3 + Δt34) of this time interval (ΔtA3) and the time interval (Δt34) from the next target point P (such as target point P3) of the actual position A2 to the target stop position Ps as the target stop time.

[0074] In addition, similar to the calculation of the target stop time based on the target speed (Δθ23 / Δt23) at the actual position A2 above, when the actual position A coincides with the target point P (in the case of the actual position A1), the target stop time may be calculated based on the target speed at the actual position A1. Also, the position of the next target point P of the actual position A may be the target stop position Ps. In this case, the controller 70 may use the time interval from the actual position A to the next target point P (target stop position Ps) as the target stop time.

[0075] The above method for obtaining (calculating) the target stop time is an example. The controller 70 may obtain the target stop time by various methods. Similar to the case where the target stop position Ps parameter is the target stop time, even when the target stop position Ps parameter is not the target stop time, the controller 70 may obtain the target stop position Ps parameter by various methods.

[0076] (Example of obtaining the stoppable position Pp parameter) The controller 70 obtains (for example, calculates) the stoppable position Pp parameter. For example, the controller 70 calculates the stoppable position Pp parameter based on the actual speed of the object OB shown in FIG. 2 (the following [Example B1]). The controller 70 calculates the stoppable position Pp parameter based on the inertia information of the object OB (the following [Example B2]). The controller 70 calculates the stoppable position Pp parameter based on the information on the strength of the specific braking amount of the actuator 30 (the following [Example B3]). The details of the calculation of the stoppable position Pp parameter are as follows.

[0077] [Example B1] The controller 70 obtains the actual speed of the object OB. This "actual speed of the object OB" is the actual speed of the object OB (for example, the actual turning speed, the actual traveling speed, etc.) at the actual position A of the object OB. The actual speed of the object OB may be the actual speed of the actuator 30 that moves the object OB. The controller 70 obtains the actual speed of the object OB based on the information detected by the detection unit 40 (see FIG. 3).

[0078] [Example B2] The controller 70 obtains the inertia information of the object OB. When the object OB rotates, the inertia information includes information on the moment of inertia of the object OB. When the object OB moves straight (translates), the inertia information of the object OB includes information on the inertial mass of the object OB. Specifically, for example, assume that the actuator 30 is the turning motor 33 and the object OB is the upper turning body 13 and the attachment 15. In this case, the inertia information of the object OB includes the moment of inertia of the upper turning body 13 and the attachment 15 with respect to the turning center of the upper turning body 13 with respect to the lower main body 11.

[0079] When the object OB is inclined with respect to the horizontal direction, it is preferable that the inertial information of the object OB is information in which the inclination information is taken into account. The inclination information includes information on the direction of the inclination and information on the amount of the inclination.

[0080] When the attachment 15 is included in the object OB and the attachment 15 is capturing a captured object (such as earth and sand), it is preferable that the inertial information of the object OB is information in which the inertial information of this captured object is taken into account.

[0081] A specific example of the calculation of the inertial information of the object OB by the controller 70 is as follows. Here, a case where the actuator 30 is the turning motor 33 and the object OB is the upper slewing body 13 and the attachment 15 will be described. The controller 70 acquires (reads) the specifications information of the upper slewing body 13 and the attachment 15 (object OB) from a storage unit (not shown). The above "specifications information" is information such as mass and shape, for example. The controller 70 acquires the attitude information of the attachment 15 and the inclination information of the machine body 10a from the attitude detection unit 50. The controller 70 acquires information (such as mass and position) of the captured object captured by the attachment 15. The mass of the captured object is calculated based on, for example, the load acting on the attachment 15 detected by the detection unit 40 (see FIG. 3). The position of the captured object is calculated based on, for example, the attitude information of the attachment 15 detected by the attitude detection unit 50 (see FIG. 1). Then, the controller 70 calculates the inertial information of the object OB based on these pieces of information.

[0082] [Example B3] The controller 70 acquires information on the strength of a specific braking amount of the actuator 30 (specific braking amount strength information). The specific braking amount strength information is, for example, information on the strength of the brake at full brake. When the actuator 30 is a motor, the specific braking amount strength information is, for example, information on the torque at a specific braking amount (e.g., torque at full brake, maximum torque). When the motor moves the object OB via a speed reducer, the above "torque" may be, for example, the combined torque of the motor and the speed reducer. When the actuator 30 is a cylinder, it is, for example, information on the thrust at a specific braking amount. The controller 70 acquires (reads) the specific braking amount strength information from the storage unit.

[0083] Based on some or all of the information in the above [Example B1] to [Example B3], the controller 70 calculates the stoppable position Pp parameter.

[0084] (Further specific examples of obtaining the stoppable position Pp parameter) A specific example will be described when the controller 70 acquires the stoppable time as the stoppable position Pp parameter.

[0085] [Example B4] Based on the inertia information (the above [Example B2]) and the specific braking amount strength information (the above [Example B3]), the controller 70 calculates the acceleration of the object OB at a specific braking amount (referred to as specific braking amount acceleration). For example, the controller 70 calculates the acceleration of the object OB at full brake (maximum acceleration). When the actuator 30 is a motor, the controller 70 calculates the specific braking amount acceleration based on the torque of the motor at a specific braking amount (specific braking amount torque) and the moment of inertia of the object OB moved by the motor. Specifically, the specific braking amount acceleration is the value obtained by dividing the specific braking amount torque by the moment of inertia (specific braking amount acceleration = specific braking amount torque / moment of inertia). When the actuator 30 is a cylinder, the controller 70 calculates the specific braking amount acceleration based on the thrust of the cylinder at a specific braking amount and the inertia information of the object OB moved by the cylinder.

[0086] [Example B5] The controller 70 calculates a speed (referred to as the deceleration - possible speed) at which the object OB can decelerate at a specific time based on the specific brake - amount acceleration (the above [Example B4]) and the specific time. The above - mentioned "specific time" may be, for example, a time interval in the work plan (Δt23, Δt34 in FIG. 4), the control cycle of the controller 70, or other specific times. Specifically, the deceleration - possible speed is the product of the specific brake - amount acceleration and the specific time (deceleration - possible speed = specific brake - amount acceleration × specific time). When the specific brake amount is full - brake, the deceleration - possible speed is the product of the maximum acceleration of the actuator 30 and the specific time (deceleration - possible speed = maximum acceleration × specific time).

[0087] The controller 70 calculates the stoppable time. As described above, the stoppable time is the time it takes for the object OB to stop at the target stop position Ps when the actuator 30 brakes with a specific brake amount from the state of the actual position A and the actual speed (the above [Example B2]). Specifically, the controller 70 calculates the stoppable time based on the actual speed (the above [Example B2]), the deceleration - possible speed (the above [Example B5]), and the specific time (refer to the above [Example B5]). More specifically, the controller 70 calculates the stoppable time from actual speed / deceleration - possible speed × specific time (stoppable time = actual speed / deceleration - possible speed × specific time).

[0088] The above method for obtaining (calculating) the stoppable time is an example. The controller 70 may obtain the stoppable time by various methods. Similar to the case where the stoppable - position Pp parameter is the stoppable time, when the stoppable position Pp is not the stoppable time, the controller 70 may also obtain the stoppable - position Pp parameter by various methods.

[0089] (Specific Brake - Amount Control) When the controller 70 satisfies the above [Condition α], it performs specific brake amount control. The specific brake amount control is control for applying a brake with a specific brake amount to the actuator 30. The specific brake amount control is control for decelerating the object OB with a brake amount stronger than the brake amount (the target brake amount) in the work plan. The specific brake amount control is control for decelerating the object OB with an acceleration smaller (a larger deceleration) than the acceleration set in the work plan. For example, the specific brake amount control is control for applying a full brake to the actuator 30 (full brake control).

[0090] Specifically, in the specific brake amount control, the controller 70 outputs a command for applying a brake with a specific brake amount to the actuator 30 to the drive control unit 17 (see FIG. 3). For example, the automatic control controller 71 shown in FIG. 3 outputs a command from the target command calculation unit 71d to the target command processing unit 73a of the vehicle body controller 73. The vehicle body controller 73 outputs a command from the target command processing unit 73a to the drive control unit 17 via the drive command calculation unit 73b. The case where the specific brake amount control is full brake control and the actuator 30 is driven by hydraulic pressure will be described. In this case, the controller 70 controls not to supply hydraulic oil to the actuator 30. Specifically, the controller 70 minimizes the discharge amount of a pump (not shown) that supplies hydraulic oil to the actuator 30, and fully opens a valve (unload valve not shown) that returns the hydraulic oil discharged from the pump to the tank. Further, the controller 70 fully closes a valve (control valve not shown) that controls the hydraulic oil flowing from the pump to the actuator 30. Also, when the actuator 30 is electric, the controller 70 controls the actuator 30 to apply an electromagnetic brake in the specific brake amount control.

[0091] By performing specific brake amount control, the difference between the actual stop position of the object OB shown in FIG. 2 and the target stop position Ps is suppressed from exceeding a threshold value (the threshold value in the above [Condition α]). As a result, the actual stop position of the object OB is suppressed from exceeding the target stop position Ps (overrunning). When the above threshold value is 0, the difference between the actual stop position of the object OB and the target stop position Ps is suppressed from exceeding 0 (overrunning). As a result of suppressing overrunning, the automatic control of the machine tool 10 can be performed with high accuracy. As a result of suppressing overrunning, it is possible to suppress (for example, avoid) a collision of the object OB with an obstacle due to overrunning.

[0092] As described above, the actuator 30 may be, for example, a motor or a cylinder. Usually, the cylinder and the object OB moved by the cylinder stop immediately when a brake is applied to the cylinder. On the other hand, the motor and the object OB moved by the motor tend to take more time to stop than the cylinder, and overrunning is likely to be a problem. Therefore, the effect of the specific brake amount control can be obtained even when the actuator 30 is a cylinder, but is more easily obtained when the actuator 30 is a motor.

[0093] (Output by the output unit 80) The controller 70 shown in FIG. 1 (for example, the automatic control controller 71) preferably causes the output unit 80 to output information on specific brake amount control. The output unit 80 preferably notifies the operator of the information on specific brake amount control.

[0094] The output unit 80 may output that the specific brake amount control is not being performed when the specific brake amount control is not being performed. The output unit 80 may output the presence or absence of the specific brake amount control.

[0095] When the specific brake amount control is being performed, the output unit 80 may output that the specific brake amount control is being performed. When the specific brake amount control has been performed, the output unit 80 may output that the specific brake amount control has been performed. The output unit 80 may output both that the specific brake amount control is being performed and that it has been performed. The reason why it is preferable for the output unit 80 to output the information on the specific brake amount control is as follows. When the specific brake amount control is performed, the actuator 30 and the object OB move (behave) differently from the target movement (the target movement when the specific brake amount control is not performed) set in the work plan. Then, the operator may recognize that a malfunction of the actuator 30 has occurred. Therefore, the output unit 80 outputs one or both of that the specific brake amount control is being performed and that the specific brake amount control has been performed, and notifies the operator. Thus, even when the movements (behaviors) of the actuator 30 and the object OB become different from the movements set in the work plan, the operator can recognize (grasp) that no malfunction of the actuator 30 has occurred.

[0096] (Brake amount increase control at the start of deceleration) As described above, when the above [Condition α] is satisfied, the controller 70 performs the specific brake amount control to make the brake amount of the actuator 30 larger than the brake amount in the work plan. Further, when the actual position A or actual speed of the object OB (see FIG. 2) deviates from the target position or target speed of the object OB at the start of deceleration of the actuator 30 (described later), the controller 70 may perform the brake amount increase control at the start of deceleration. As shown in FIG. 5, the brake amount increase control at the start of deceleration is a control that makes the brake amount of the actuator 30 (see FIG. 2) during deceleration larger than the brake amount (original brake amount) that was targeted before the deceleration of the actuator 30. In the brake amount increase control at the start of deceleration, the controller 70 makes the brake amount of the actuator 30 larger than the brake amount in the work plan even if the above [Condition α] is not satisfied (earlier than when it is satisfied).

[0097] By performing the control to increase the braking amount at the start of deceleration, the frequency of performing the specific braking amount control is reduced. Further, even when the specific braking amount control is performed after the control to increase the braking amount at the start of deceleration, the actual speed of the object OB (see FIG. 2) at the start of the specific braking amount control can be decreased. Therefore, the overrunning of the object OB is more suppressed.

[0098] The controller 70 performs the control to increase the braking amount at the start of deceleration on the condition that one or both of the following [Condition β1] and [Condition β2] are satisfied (that is, [Condition β] is satisfied).

[0099] The condition for the controller 70 to perform the control to increase the braking amount at the start of deceleration may include the following [Condition β1]. [Condition β1] is that, at the start of deceleration of the actuator 30, the actual position A of the object OB shown in FIG. 2 is closer to the target stop position Ps than the target position of the object OB (the target position at the start of deceleration). The above “at the start of deceleration” is the time when the actuator 30 (the object OB) shifts from the non-deceleration state to the deceleration state. The non-deceleration state includes the acceleration state and the constant-speed state. For example, assume that the relationship between the timing at which deceleration is to be started and the target position of the object OB at this timing is set in the work plan. In this case, when the actual position A of the object OB at this timing is closer to the target stop position Ps than the target position, the above [Condition β1] is satisfied.

[0100] The conditions under which the controller 70 performs the control to increase the braking amount at the start of deceleration may include the following [Condition β2]. [Condition β2] is that when the actuator 30 starts decelerating, the actual speed of the object OB is faster than the target speed of the object OB (the target speed at the start of deceleration). For example, assume that the relationship between the timing at which deceleration is to start and the target speed of the object OB at this timing is set in the work plan. In this case, when the actual speed of the object OB at this timing is faster than the target speed, the above [Condition β2] is satisfied. Also, assume that the relationship between the position at which deceleration is to start and the target speed of the object OB at this position is set in the work plan. In this case, when the actual speed of the object OB at this position is faster than the target speed, the above [Condition β1] is satisfied.

[0101] (Specific example of the processing of the controller 70) Referring to the flowchart shown in FIG. 6, a specific example of the processing of the controller 70 will be described. Hereinafter, unless otherwise specified, the description will be made in the order of the processing. Note that the order of the processing can be changed in various ways. Steps S11 to S31 will be described with reference to FIG. 6.

[0102] In step S11, the controller 70 (specifically, the work plan setting unit 71b) sets a work plan. At this time, the working machine 10 shown in FIG. 1 is in an idling state. Specifically, the drive source of the actuator 30 is in a driven state (for example, a state where the engine is running, a state where the power is on), and the actuator 30 is in a non-moving state.

[0103] In step S12, the controller 70 (for example, the work plan modification unit 71c) determines whether to modify the work plan (see step S13). When the controller 70 modifies the work plan (YES in step S12), the processing flow proceeds to step S13 to modify the work plan. When the controller 70 does not modify the work plan (NO in step S12), the processing flow proceeds to step S14.

[0104] In step S13, the controller 70 (specifically, the work plan modification unit 71c) modifies the work plan. The modification of the work plan performed in this step S13 is a modification of the work plan based on the equipment capabilities (specifications, performance, etc.) of the work machine 10, and is not a modification of the work plan by specific brake amount control. For example, in the equipment capabilities of the work machine 10, there may be a set work plan that is impossible to achieve, such that the work machine 10 cannot move as per the work plan. In such a case, the work plan modification unit 71c modifies the work plan so that the work machine 10 can move as per the work plan. The above "equipment capabilities" are, for example, the capabilities (performance) of the actuator 30. When the actuator 30 is driven by hydraulic pressure, the equipment capabilities may include the maximum flow rate and the minimum flow rate of a pump (not shown) that supplies hydraulic oil to the actuator 30. When the actuator 30 is a motor, the equipment capabilities may include the maximum torque of the motor. When the actuator 30 is a cylinder, the equipment capabilities may include the maximum thrust of the cylinder. The equipment capabilities may also be information that takes into account the inertia information (described above) of the work machine 10.

[0105] In step S14, the controller 70 (for example, the automatic control controller 71) finalizes the work plan and causes the output unit 80 to output the information (finalized behavior) of the finalized work plan. The output unit 80 notifies the operator of the information of the finalized work plan.

[0106] In step S21, the controller 70 (for example, the automatic control controller 71) determines whether to perform automatic control of the working machine 10. For example, the controller 70 determines whether the automatic control switch 63 (see FIG. 3) is on. For example, the controller 70 does not start (waits) the automatic control of the working machine 10 until it determines to perform automatic control (until it becomes YES in step S21). When the controller 70 determines to perform automatic control (when it is YES in step S21), it starts the automatic control of the working machine 10. Then, the working machine 10 moves by automatic control. While the working machine 10 is moving by automatic control, the controller 70 repeats the processes from step S22 to step S25. For example, the controller 70 repeats the processes from step S22 to step S25 at a predetermined cycle (control cycle).

[0107] In step S22, the controller 70 (for example, the work plan modification unit 71c (the same applies hereinafter)) acquires the target stop position Ps parameter. For example, the controller 70 acquires the target stop time (details are as described above).

[0108] In step S23, the controller 70 acquires the stoppable position Pp parameter. For example, the controller 70 acquires the stoppable time (details are as described above).

[0109] In step S24, the controller 70 determines whether to perform specific brake amount control. The controller 70 determines whether the above [condition α] (for example, [condition α1]) is satisfied. Specifically, for example, the controller 70 determines whether the stoppable time is equal to or greater than the target stop time. When the controller 70 determines that [condition α] is satisfied (when it is YES in step S24), it performs specific brake amount control (step S24y) and advances the process to step S25. When the controller 70 determines that [condition α] is not satisfied (when it is NO in step S24), it does not perform specific brake amount control and advances the process to step S25.

[0110] In step S25, the controller 70 (specifically, the automatic control controller 71) determines whether to end the automatic control of the working machine 10. For example, the controller 70 determines whether the automatic control switch 63 (see FIG. 3) is off. When the controller 70 determines to end the automatic control (YES in step S25), it advances the process to step S31. When the controller 70 determines not to end the automatic control (NO in step S25), it continues the automatic control and returns the process to step S22.

[0111] In step S31, the controller 70 (specifically, the automatic control controller 71) ends the automatic control. The working machine 10 stops moving by automatic control and, for example, enters an idling state. After ending the automatic control, the controller 70 may return the process to "START" or may end the process.

[0112] (Effect of the First Invention) The effects of the brake control system 1 shown in FIG. 1 are as follows. The brake control system 1 includes an actuator 30, an object OB, and a controller 70. The actuator 30 is mounted on the working machine 10. The object OB is moved by the actuator 30. The controller 70 controls the actuator 30. As shown in FIG. 2, let the target stop position of the object OB be the target stop position Ps. Let the position where the object OB can stop when the actuator 30 applies a brake with a specific brake amount be the stoppable position Pp.

[0113] [Configuration 1] When the controller 70 determines that the difference between the target stop position Ps and the stoppable position Pp is equal to or less than a threshold value, the controller 70 performs specific brake amount control, which is control to cause the actuator 30 to apply a brake with a specific brake amount.

[0114] According to the above [Configuration 1], the difference between the actual stop position of the object OB stopped by the specific brake amount control and the target stop position Ps can be made equal to or less than the threshold value or approximately equal to or less than the threshold value. When the threshold value is set to a small value, the actual stop position of the object OB can be made to coincide with or approximately coincide with the target stop position Ps. Therefore, it is possible to suppress the actual stop position of the object OB from exceeding (overrunning) the target stop position Ps.

[0115] (Effect of the second invention) [Configuration 2] When the controller 70 determines that the stoppable position Pp is equal to or exceeds the target stop position Ps, the controller 70 performs the specific brake amount control.

[0116] The above [Configuration 2] is the case where the threshold value of the above [Configuration 1] is 0. According to the above [Configuration 2], it is possible to suppress the actual stop position of the object OB from exceeding the target stop position Ps.

[0117] (Effect of the third invention) [Configuration 3] The controller 70 calculates a parameter (stoppable position Pp parameter) indicating the stoppable position Pp based on the actual speed of the object OB, the inertia information of the object OB, and the information on the strength of the specific brake amount of the actuator 30.

[0118] According to the above [Configuration 3], the controller 70 can accurately calculate the stoppable position Pp parameter. Here, the specific brake amount control is performed when the controller 70 determines that the difference between the target stop position Ps and the stoppable position Pp is equal to or less than the threshold value (the above [Configuration 1]). In the above [Configuration 3], since the accuracy of the target stop position Ps can be increased, the timing for performing the specific brake amount control can be made more appropriate. As a result, it is possible to more reliably suppress the actual stop position of the object OB from exceeding the target stop position Ps.

[0119] (Effect of the fourth invention) [Configuration 4] As shown in FIG. 1, the brake control system 1 includes an output unit 80 that notifies the operator of one or both of the fact that specific brake amount control is being performed and the fact that specific brake amount control has been performed.

[0120] According to the above [Configuration 4], one or both of the fact that specific brake amount control is being performed and the fact that specific brake amount control has been performed can be notified to the operator. Therefore, the operator can be made to understand that the movement (behavior) of the actuator 30 applying the brake with a specific brake amount is not a malfunction of the actuator 30.

[0121] (Effect of the Fifth Invention) [Configuration 5] The controller 70 performs deceleration start-time brake amount increase control on the condition that one or both of the following [Condition 5A] and [Condition 5B] are satisfied. The deceleration start-time brake amount increase control is control to make the brake amount of the actuator 30 during deceleration larger than the brake amount that was targeted before the deceleration of the actuator 30, as shown in FIG. 5. [Condition 5A] At the start of deceleration of the actuator 30, the actual position A (see FIG. 2) of the object OB (see FIG. 2) is closer to the target stop position Ps than the target position of the object OB. [Condition 5B] At the start of deceleration of the actuator 30, the actual speed of the object OB is faster than the target speed of the object OB.

[0122] With the above [Configuration 5], the following effects can be obtained. The above [Condition 5A] is a situation where there is a possibility that the actual stop position of the object OB may exceed the target stop position Ps (the same applies to the above [Condition 5B]). In this situation, the control to increase the brake amount at the start of deceleration is performed. Therefore, even in a situation where the condition for performing the specific brake amount control (see the above [Configuration 1]) is not satisfied, the brake amount becomes larger than the brake amount targeted before deceleration of the actuator 30. Therefore, the frequency of performing the specific brake amount control decreases, and it is possible to suppress the actual stop position of the object OB from exceeding the target stop position Ps. Further, even when the specific brake amount control is performed, the speed of the object OB at the start of the specific brake amount control can be reduced. Therefore, it is possible to more reliably suppress the actual stop position of the object OB from exceeding the target stop position Ps.

[0123] (Modification example) The above embodiments may be variously modified. For example, various combinations of the modification examples of the above embodiments may be made. For example, the number of the components (including modification examples) of the above embodiments may be changed, and some of the components may not be provided. For example, the connection of each component shown in FIG. 3 may be changed. For example, the arrangement of the components may be changed. For example, the inclusion relationship of the components may be variously changed. For example, what has been described as a lower-level component included in a certain upper-level component may not be included in this upper-level component and may be included in other components. For example, what has been described as a plurality of different members or parts may be made into one member or part. For example, what has been described as one member or part may be divided and provided as a plurality of different members or parts. For example, the order of the steps of the flowchart shown in FIG. 6 may be changed, and some of the steps may not be performed. For example, values such as threshold values and setting values may be preset in the controller 70 shown in FIG. 3, or may be directly set by a manual operation of an operator (operation of the input unit 60). Values such as threshold values and setting values may be calculated in the controller 70 based on information set by a manual operation of an operator, or may be calculated in the controller 70 based on information detected by the detection unit 40. For example, values such as threshold values and setting values may not be changeable, may be changed by a manual operation, or may be automatically changed by the controller 70 according to some conditions. For example, the controller 70 may perform processes (calculations, determinations, etc.) substantially the same as the processes (calculations, determinations, etc.) of the above embodiments (including modification examples). Various processes may be variously combined. For example, each component may have only a part of each feature (action function, arrangement, shape, operation, etc.).

Description of Reference Numerals

[0124] 1 Brake control system 10 Machine tool 30 Actuator 70 Controller 80 Output unit OB Object Pp Stoppable position Ps Target stop position

Claims

1. An actuator mounted on a working machine, An object moved by the actuator, A controller for controlling the actuator, Comprising, Taking the target stop position of the object as the target stop position, When the position where the object can stop when the actuator applies a brake with a specific brake amount is defined as the stoppable position, When the controller determines that the difference between the target stop position and the stoppable position is equal to or less than a threshold value, the controller performs specific brake amount control, which is control to cause the actuator to apply the brake with the specific brake amount. Brake control system.

2. The brake control system according to claim 1, When the controller determines that the stoppable position is equal to or exceeds the target stop position, the controller performs the specific brake amount control. Brake control system.

3. The brake control system according to claim 1, The controller calculates a parameter indicating the stoppable position based on the actual speed of the object, the inertia information of the object, and information on the strength of the specific brake amount of the actuator. Brake control system.

4. The brake control system according to claim 1, Comprising an output unit for notifying the operator of one or both of the fact that the specific brake amount control is being performed and the fact that the specific brake amount control has been performed. Brake control system.

5. The brake control system according to claim 1, The controller, At the start of deceleration of the actuator, the actual position of the object is closer to the target stop position than the target position of the object, At the start of deceleration, the actual speed of the object is faster than the target speed of the object, On the condition that one or both of the above are satisfied, the controller performs deceleration start-time brake amount increase control, which is control to make the brake amount during deceleration of the actuator larger than the brake amount targeted before deceleration of the actuator. Brake control system.

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