JP6106129B2 - Excavation control equipment for construction machinery - Google Patents

Description

  The present invention relates to an excavation control device that limits an area in which a work device of a construction machine can move during excavation work.

  A typical example of a construction machine is a hydraulic excavator. The hydraulic excavator has a front work device composed of a plurality of arms such as a boom, an arm, and a bucket, and a desired work is performed by an operator operating each arm of the front work device with an operation lever in a cab. It is. Since the operation of each arm is performed by rotating a plurality of joints, the operator's skill is required to perform an operation for forming a plane such as slope shaping and leveling with only the front working device.

  As a technique for supporting the operation of such work, as shown in Patent Document 1, a technique called area restriction for controlling the movement of the front work device so as to allow excavation only in a predetermined area (set area) set in advance is proposed. Has been.

JP-A-10-008490

  In the technique disclosed in Patent Document 1 described above, the boundary of the setting area is defined by a straight line extending infinitely. On the other hand, the final shape (target shape) of the object to be excavated obtained by the excavation work of the construction machine is represented by a drawing such as a construction drawing. Since the target shape is usually defined by one or a plurality of surfaces, it has a terminal end, and the terminal end appears as an end point on the cross-sectional view. Further, for example, in the cross-sectional view of the slope, for example, a line segment indicating another plane is connected to the end point at the slope and the target shape is often defined by a plurality of continuous line segments. That is, the target shape on the actual cross-sectional view (construction drawing) is not defined by an infinitely extending straight line, but is defined by one or more line segments having ends.

  Therefore, in the situation where the target shape is shaped according to the construction drawing by the technique of the above-mentioned document, the boundary (straight line) of the setting area must be set along a certain line segment included in the target shape, Excessive excavation beyond the end point of the line segment to the part that is not originally required for excavation, or conversely, there may be a hollow excavation that remains in the vicinity of the end point without being excavated. There is. In addition, when the target shape is defined by a plurality of continuous line segments, it is necessary to perform excavation work while changing the boundary of the set area each time according to the plurality of line segments. There is a risk that the change of the boundary of the time will not be in time, and excessive digging and empty digging may occur.

  It is an object of the present invention to provide a construction machine that can suppress the occurrence of excessive digging and empty digging even when a target shape is defined by a line segment when executing area restriction control that defines a boundary of a set area with a straight line. An object is to provide an excavation control device.

  In order to achieve the above object, an excavation control device for a construction machine according to the present invention drives an articulated work device configured by connecting a plurality of driven members, and the plurality of driven members, respectively. A plurality of hydraulic actuators, a plurality of operation devices for instructing operations of the plurality of hydraulic actuators according to operation amounts, respectively, and driving according to operation signals output according to operation amounts of the plurality of operation devices A plurality of flow rate control valves for controlling the flow rate and direction of hydraulic pressure supplied to the plurality of hydraulic actuators, and a region for controlling the work device to move in a region on and above a preset boundary surface A control device that executes limit control, and the target shape of the work device by excavation work is defined by at least one line segment defined by two points, and the control device The operation signal is corrected so as to reduce the operation speed of at least one of the plurality of hydraulic actuators when the tip of the working device approaches one of the plurality of points defining the at least one line segment. It is characterized by that.

  According to the present invention, since the actuator speed is reduced in the vicinity of a point that defines the target shape, it is possible to suppress the occurrence of excessive digging and empty digging.

It is a figure which shows the excavation control apparatus of the hydraulic shovel by the embodiment of this invention with the hydraulic drive unit. It is a figure which shows the external appearance of the hydraulic shovel to which this invention is applied. It is a functional block diagram which shows the control function of a control unit. It is a figure which shows the setting method of an excavable area | region. It is a figure which shows the relationship with the distance from the boundary of the setting area | region when calculating | requiring the limit value of bucket tip speed. It is a figure which shows the difference in the correction | amendment operation | movement of the bucket tip speed by the boom in the case where it exists in the setting area | region, when it exists on the boundary of a setting area | region, and when it exists out of a setting area | region. It is a figure which shows an example of the correction | amendment action locus | trajectory when a bucket front-end | tip exists in a setting area | region. It is a figure which shows an example of correction | amendment operation | movement locus | trajectory when a bucket front-end | tip is outside a setting area | region. It is a figure which shows the example of the distance and angle used when performing a deceleration process. It is a flowchart of a deceleration process. It is a figure which shows an example of the table which calculates | requires the distance coefficient Kd used for a deceleration process. It is a figure which shows an example of the table which calculates | requires angle coefficient Ka used for a deceleration process. It is a figure which shows an example at the time of setting the deceleration coefficient K so that the upper limit La may become smaller than the limit value a less than distance R1 of the shape change point vicinity.

  First, before describing an embodiment of the present invention, main features included in a construction machine excavation control apparatus according to the present invention will be described.

  (1) An excavation control device for a construction machine according to the present invention includes an articulated work device configured by connecting a plurality of driven members, and a plurality of hydraulic actuators respectively driving the plurality of driven members. A plurality of operation devices for instructing the operations of the plurality of hydraulic actuators according to operation amounts, respectively, and driven according to operation signals output according to operation amounts of the plurality of operation devices, A plurality of flow rate control valves for controlling the flow rate and direction of hydraulic pressure supplied to the hydraulic actuator, and on a boundary surface set in advance based on the posture / position of the working device and the operation amounts of the operating devices. And a control device that executes region restriction control for controlling the work device to move in the region above the target device. The target shape of the work device by excavation work is regulated by two points. Defined by at least one line segment, and when the tip of the working device approaches one of a plurality of points defining the at least one line segment, the control device includes the plurality of hydraulic actuators. The operation signal is corrected so as to reduce at least one operation speed.

  According to the excavation control device for a construction machine configured as described above, a tip portion (for example, a bucket) of the working device is located at any of the plurality of points (for example, shape change points described later) that define the target shape. When approaching, the operation speed of at least one of the plurality of hydraulic actuators (for example, an arm cylinder) is reduced, and the speed of the tip is reduced. Thereby, the speed of the tip of the working device is sufficiently reduced before reaching any of the plurality of points defining the target shape, so that excessive digging or empty digging in the vicinity of any of the plurality of points is performed. Can be suppressed.

  In addition, it is preferable that the boundary surface is set so as to include a line segment including a point closest to the distal end portion of the working device among the plurality of line segments defining the target shape. If configured in this way, the speed of the working device is sufficiently reduced at the stage before the tip of the working device reaches the boundary surface, so the area restriction control along the boundary surface becomes easy. The accuracy of the shape formed by excavation work can be improved. In that case, it is preferable that the boundary surface is automatically set according to the position of the distal end portion of the working device (for example, the distance from the distal end portion of the plurality of line segments is the shortest). Set the boundary surface to include things). When the boundary surface is selected in this way, the labor for setting the boundary surface can be saved.

  Further, as an acquisition method of at least one line segment that defines the target shape, a three-dimensional construction drawing in which the three-dimensional shape of the target shape is defined by a polygon is used for all of the plurality of driven members related to the work device. The target shape is defined by a plurality of line segments appearing in the cross section. As described above, in this embodiment, the target shape used for the region restriction control is defined on the two-dimensional plane.

  By the way, when there are two or more line segments defining the target shape, the distance from each of the two line segments close to the distal end portion of the working device to the distal end portion is calculated, and the distance is calculated based on the distance. There is a method for reducing the speed of the tip. However, since the method calculates the distance between the two line segments and the tip, the calculation load on the computer is high, and a considerable specification is required of the computer. On the other hand, according to the present invention, since excavation control can be realized only by calculating the distance between two points (that is, one line segment) and the tip, in addition to not requiring two line segments. Thus, there is an advantage that the computational load of the computer can be remarkably reduced.

  (2) In the above (1), preferably, the control device has the at least one of the plurality of points according to a distance from a point closest to the tip of the working device to a tip of the working device. The degree of deceleration of the two hydraulic actuators is adjusted.

  Thus, adjusting the degree of deceleration according to the distance from the closest point can prevent the operator from feeling uncomfortable in operation. As a specific method of deceleration, there is a method in which when the distance from the closest point is equal to or less than a set value, the deceleration degree is monotonously increased as the distance decreases. That is, in this case, the speed of the tip is adjusted so as to decrease as the distance decreases. Note that the monotonic increase here indicates a monotonic increase in a broad sense including the case where the speed is constant in a certain distance section.

  In the above, as an example of the method for determining “the point closest to the tip of the working device”, any point is “closest to the point based on the shortest distance from the plurality of points to the tip of the working device. There is a method of making a decision based on whether or not it falls under “point”. The shortest distance in this case corresponds to the “closest point” when the radius of the circle is the smallest when the smallest circle that touches the tip is centered on each point.

  (3) In the above (1) or (2), preferably, the target shape is defined by a plurality of continuous line segments, and the control device includes a tip of the working device among the plurality of points. The degree of deceleration of the at least one hydraulic actuator is adjusted according to the size of the angle formed by the two line segments adjacent to the point closest to.

  When the excavation control device is configured in this manner, a deceleration degree suitable for the size of the angle formed by the two line segments can be appropriately selected. When combined with the above (2), the deceleration degree may be adjusted in consideration of both by adding or multiplying the deceleration degree of (2) and the deceleration degree of (3).

  (4) In the above (3), preferably, the control device decreases the degree of deceleration of the at least one hydraulic actuator as the angle between the two adjacent line segments approaches 0 degrees. It is characterized by adjusting to. The “angle formed by the two adjacent line segments” may exceed +90 degrees or be smaller than −90 degrees depending on the selection method, but here, it is from −90 degrees to +90 degrees. An angle shall be selected. That is, the “magnification” is always 90 or less (details of the definition of angle in this paper will be described later).

  In general, the larger the angle formed by the two line segments, the more precise operation of the tip portion is required. Therefore, as described in (4), the speed is reduced according to the size of the angle formed by the two line segments. When the degree is adjusted, the tip portion can be easily controlled by an operator operation. As a specific method of deceleration, there is a method in which the degree of deceleration when the angle formed is zero is minimized, and the degree of deceleration is monotonously increased as the angle formed increases toward +90 degrees or -90 degrees. That is, in this case, the speed of the tip portion is adjusted so as to decrease as the size of the angle formed increases. Note that the monotonic increase here indicates a monotonic increase in a broad sense including the case where the speed is constant in a certain distance section.

  In the above, “when the angle between the two line segments is 0 degree” corresponds to, for example, a case where a flat surface is defined by the two line segments. In this case, the flat surface is There is a point (referred to as an internal point) defined by three points located on the same straight line and located between two points at both ends. In such a case, according to the excavation control device configured as in (1), although the tip portion approaches the internal point that originally does not need to be decelerated, it is decelerated. If comprised in this way, when the said front-end | tip part approaches such an internal point, deceleration can be suppressed and smooth excavation is realizable.

  Further, when the magnitude of the angle formed by the two line segments is 0, the deceleration control in the above (1) is not necessary, so that it may be set so that the deceleration control according to the present application is not performed exceptionally. (That is, it is set not to perform the deceleration control of (1) above). In this way, only the area restriction control is performed in the vicinity of the internal point, so that smooth excavation without deceleration can be realized.

  (5) In any one of the above (1) to (4), preferably, the control device decelerates the at least one hydraulic actuator based on an operation direction of a distal end portion of the working device with respect to the closest point. It is characterized by adjusting the degree.

  According to the excavation control device configured as described above, it is possible to prevent the operator from feeling uncomfortable in operation. As a specific method of deceleration, if the movement direction of the tip portion is a direction away from the nearest point, the deceleration degree is set to monotonously decrease as the distance from the nearest point increases, If the movement direction of the tip portion is a direction approaching the closest point, there is a method in which the deceleration degree is monotonously increased as the distance from the closest point decreases. Note that the degree of deceleration according to the distance may be different or the same between the direction away from the closest point and the direction approaching. Also, the monotonic increase / monotonic decrease here indicates a monotonic increase / monotonic decrease in a broad sense including the case where the speed is constant in a certain distance section, as described above.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment when the present invention is applied to a hydraulic excavator will be described with reference to the drawings. In the following, a hydraulic excavator provided with a bucket (1c) is exemplified as an attachment at the tip of the working device, but the present invention may be applied to a hydraulic excavator provided with an attachment other than the bucket. Further, in the following description, when there are a plurality of identical components, an alphabet may be added to the end of the code (number), but the alphabet may be omitted and the plurality of components may be described collectively. is there. For example, when there are three identical pumps 300a, 300b, and 300c, these may be collectively referred to as pump 300.

  In FIG. 1, a hydraulic excavator to which the present invention is applied includes a hydraulic pump 2, a boom cylinder 3a, an arm cylinder 3b, a bucket cylinder 3c, a swing motor 3d, and left and right travelings driven by pressure oil from the hydraulic pump 2. Between a plurality of hydraulic actuators including motors 3e and 3f, a plurality of operation lever devices 4a to 4f provided corresponding to each of the hydraulic actuators 3a to 3f, and between the hydraulic pump 2 and the plurality of hydraulic actuators 3a to 3f. A plurality of flow rate control valves that are connected and controlled by an operation signal output in accordance with the operation amount and operation direction of the operation lever devices 4a to 4f and control the flow rate and direction of the pressure oil supplied to the hydraulic actuators 3a to 3f. Opens when the pressure between the hydraulic pump 2 and the flow rate control valves 5a to 5f exceeds a set value. And a leaf valve 6, which constitute a hydraulic drive system for driving driven members of the hydraulic excavator.

  As shown in FIG. 2, the hydraulic excavator includes a multi-joint type front working device 1A configured by connecting a plurality of driven members (boom 1a, arm 1b, and bucket 1c) that rotate in the vertical direction, It is comprised with the vehicle body 1B which consists of the upper turning body 1d and the lower traveling body 1e, and the base end of the boom 1a of 1 A of front work apparatuses is supported by the front part of the upper turning body 1d. The boom 1a, the arm 1b, the bucket 1c, the upper swing body 1d, and the lower traveling body 1e are respectively driven by the boom cylinder 3a, the arm cylinder 3b, the bucket cylinder 3c, the swing motor 3d, and the left and right traveling motors 3e, 3f. The members are configured, and their operations are instructed by the operation lever devices 4a to 4f.

  The operation lever devices 4a to 4f are of a hydraulic pilot system, and the pilot pressures corresponding to the operation amounts and operation directions of the operation levers 4a to 4f operated by the operators are used as operation signals via the pilot lines 44a to 49b. The corresponding flow control valves 5a to 5f are supplied to hydraulic drive units 50a to 55b to drive these flow control valves.

  The excavation control system used for area restriction is installed at a position that does not block the operator's field of view, such as above the operation panel in the driver's cab, and a restriction control switch 7 that switches validity / invalidity of area restriction control. Information on the target shape of the excavation target (target), which is necessary for setting the excavable area (sometimes referred to as “setting area”) in which the predetermined part (for example, the front end of the bucket 1c serving as the front end of the working device 1A) can move (Form information) including various information including the storage device 20 and the rotation fulcrums of the boom 1a, the arm 1b, and the bucket 1c, and each rotation as a state quantity related to the position and posture of the front working device 1A. Angle detectors 8a, 8b, and 8c that detect angles, and an inclination angle that detects an inclination angle in the front-rear direction of the vehicle body 1B with respect to a reference plane (for example, a horizontal plane) 8d, pressure detectors 60a, 60b, which are provided on pilot lines 44a, 44b of the operation lever device 4a for the boom 1a, detect pilot pressure (operation signal) as the operation amount of the operation lever device 4a, and the arm 1b. Pressure detectors 61a and 61b that are provided on pilot lines 45a and 45b of the control lever device 4b for detecting pilot pressure (operation signal) as the operation amount of the control lever device 4b, and the primary port side is connected to the pilot pump 43. Proportional solenoid valve 10a for reducing the pilot pressure from pilot pump 43 according to the electrical signal and outputting it, pilot line 44a of operation lever device 4a for boom 1a and the secondary port side of proportional solenoid valve 10a, Pilot pressure in the pilot line 44a and control pressure output from the proportional solenoid valve 10a The high pressure side is selected and installed on the shuttle valve 12 that leads to the hydraulic drive unit 50a of the flow control valve 5a, and the pilot line 44b of the operation lever device 4a for the boom 1a, and the pilot pressure in the pilot line 44b according to the electrical signal The proportional solenoid valve 10b that depressurizes and outputs the pressure, and the proportional solenoid valve 11a that is installed in the pilot line 45a of the operating lever device 4b for the arm 1b and that depressurizes and outputs the pilot pressure in the pilot line 45a according to the electrical signal. And a proportional solenoid valve 11b that is installed in the pilot line 45b of the operating lever device 4b for the arm 1b and that reduces and outputs the pilot pressure in the pilot line 45b in accordance with an electrical signal, and a target stored in the storage device 20 Shape information, detection signals of the angle detectors 8a, 8b, 8c and the inclination angle detector 8d, and the pressure detector 60 Operation signals for inputting the detection signals a, 60b, 61a, 61b, setting the excavable area (setting area) in which the tip of the bucket 1c can move, and performing excavation control (area restriction control) with limited area The control unit (control device) 9 is a computer that outputs an electric signal for correcting (pilot pressure) to the proportional solenoid valves 10a and 10b.

  The control function of the control unit 9 is shown in FIG. The control unit 9 includes a front posture calculation unit 9a, a region setting calculation unit 9b, a bucket tip speed limit value calculation unit 9c, an arm cylinder estimated speed calculation unit 9d, a bucket tip speed calculation unit 9e by an arm, and a bucket tip speed by a boom. Limit value calculation unit 9f, boom cylinder speed limit value calculation unit 9g, boom pilot pressure limit value calculation unit 9h, region limit control switching calculation unit 9r, boom valve command calculation unit 9i, arm pilot pressure limit value calculation Each function of the unit 9j, the arm valve command calculation unit 9k, and the arm cylinder target speed calculation unit 9z is provided.

  In the front posture calculation unit 9a, the front working device is based on the rotation angles of the boom 1a, the arm 1b, and the bucket 1c detected by the angle detectors 8a to 8c and the inclination angle detector 8d and the inclination angles of the vehicle body 1B. The position and orientation of 1A are calculated. An example of this will be described with reference to FIG. In this example, the position of the toe (tip) P1 of the bucket 1c of the front working device 1A is calculated. Here, for the sake of simplicity of explanation, the detection value of the inclination angle detector 8d is not considered.

  In FIG. 4, the storage device 20 of the control unit 9 stores the dimensions of the front work device 1A and the vehicle body 1B. The front posture calculation unit 9a detects these data and the angle detectors 8a, 8b, and 8c. The position of the bucket tip P1 is calculated using the values of the rotation angles α, β, and γ. At this time, the position of P1 is obtained, for example, as coordinate values (X, Y) in the XY coordinate system with the pivot point of the boom 1a as the origin. The XY coordinate system is an orthogonal coordinate system in a vertical plane fixed to the main body 1B. The distance between the pivot fulcrum of the boom 1a and the pivot fulcrum of the arm 1b is L1, the distance between the pivot fulcrum of the arm 1b and the pivot fulcrum of the bucket 1c is L2, and the distance between the pivot fulcrum of the bucket 1c and the tip of the bucket 1c. If the distance is L3, the coordinate values (X, Y) of the XY coordinate system can be obtained from the following equations (1) and (2) from the rotation angles α, β, γ.

  Based on the target shape information obtained from the storage device 20, the area setting calculation unit 9 b performs setting calculation of an excavable area (setting area) in which the tip (P 1) of the bucket 1 c can move. The target shape information refers to a plurality of continuous shapes (target shapes) of a final excavation object obtained by excavation work by the front working device 1A on a vertical plane passing through the centers of the boom 1a, the arm 1b, and the bucket 1c. Information defined by line segments. Each line segment in the plurality of line segments is defined by two points having coordinate information. For example, in FIG. 9 described later, a target shape (in FIG. 9) is determined by a line segment connecting point A (xA, zA) and point B (xB, zB). A part of the slope) is prescribed.

  As a method for acquiring target shape information, for example, in a three-dimensional construction drawing in which a three-dimensional shape of a target shape (for example, a slope shape) is defined by polygons, a vertical plane that passes through the centers of the boom 1a, arm 1b, and bucket 1c is used. There is one that cuts the three-dimensional shape and defines a shape formed by a plurality of continuous line segments appearing in the cross section as a target shape.

  The excavable area where the tip of the bucket 1c can move is defined by the boundary surface, and the area above and above the boundary surface is the excavable area. The boundary surface of the present embodiment is defined by a straight line including at least one line segment among a plurality of line segments that define the target shape. Hereinafter, the boundary surface may be referred to as “boundary L”.

  The boundary L in the present embodiment is automatically generated and selected as appropriate according to the position of the tip of the bucket 1c. Specifically, a line segment having the shortest distance from the tip (P1) of the bucket 1c is extracted from a plurality of line segments defining the target shape, and a straight line including the line segment is generated and selected as the boundary L. The The boundary L is first defined by a linear equation in the XY coordinate system set on the construction machine, and then converted into a linear equation in the orthogonal coordinate system XaYa coordinate system having the origin on the straight line and the straight line as one axis. . At that time, conversion data from the XY coordinate system to the XaYa coordinate system is obtained. The generation / selection of the boundary L is not limited to the above, and various methods can be employed. As an example, a line segment having the same X coordinate as the bucket tip (P1) in the XY coordinate system is searched from the cross section (target shape) of the three-dimensional construction drawing, and a straight line including the line segment related to the search result. Is a boundary L.

  The bucket tip speed limit value calculation unit 9c calculates a limit value a of a component perpendicular to the bucket tip speed boundary L based on the distance D from the bucket tip (P1) boundary L. The calculation of the limit value a is performed by storing the relationship between the limit value a and the distance D as shown in FIG. 5 in the storage device 20 of the control unit 9, and reading this relationship.

  In FIG. 5, the horizontal axis indicates the distance D from the bucket tip boundary L, the vertical axis indicates the limit value a of the component perpendicular to the bucket tip speed boundary L, the horizontal axis distance D and the vertical axis speed limit. As for the value a, the direction from the outside of the setting area to the inside of the setting area is the (+) direction as in the XaYa coordinate system. The relationship between the distance D and the limit value a is that when the bucket tip is within the set region, the speed in the (−) direction proportional to the distance D is set as the limit value a of the component perpendicular to the bucket tip speed boundary L, When the bucket tip is out of the region, the speed in the (+) direction proportional to the distance D is determined to be the limit value a of the component perpendicular to the bucket tip velocity boundary L. Therefore, within the set area (in the excavable area), the speed is reduced only when the component perpendicular to the boundary L of the bucket tip speed exceeds the limit value in the (−) direction, and outside the set area (outside the excavable area), The bucket tip is accelerated in the (+) direction.

  The arm cylinder estimated speed calculation unit 9d uses the command value (pilot pressure (operation signal)) to the flow control valve 5b detected by the pressure detectors 61a and 61b and the flow characteristics of the arm flow control valve 5b to determine the arm cylinder. Estimate the estimated speed.

  In the arm cylinder target speed calculation unit 9z, in order to prevent excessive digging and empty digging when the boundary L is switched according to the bucket tip position, the bucket tip P1 and the boundary L as illustrated in FIG. Based on the positional relationship between the two points A and B (hereinafter sometimes referred to as “shape change points”) that define the line segment (n), the arm cylinder target speed is calculated by the process described below.

  Here, taking the situation shown in FIG. 9 as an example, the arm cylinder target speed calculation processing by the arm cylinder target speed calculation unit 9z will be described with reference to the flowchart of FIG. FIG. 9 shows a situation where the line segment (n) is included in the boundary L of the region restriction. Note that the processing shown in FIG. 10 is repeated at a predetermined control cycle in the same manner as the processing of each arithmetic unit shown in FIG.

  In step S100, the distance RA from the bucket tip P1 to the point A that is the shape change point and the distance RB from the bucket tip P1 to the point B that is the shape change point are obtained, and the process proceeds to step S110. The coordinates of the bucket tip P1 used in calculating the distances RA and RB can be calculated from, for example, the output value of the front posture calculation unit 9a and the current position of the hydraulic excavator, and the coordinates of the points A and B are obtained from the construction drawing. It can be acquired from the stored storage device 20.

  Regarding step S100, in the situation of FIG. 9, distances from the toe P1 of the bucket 1c (the front end portion of the front working device 1A) to the shape change points A and B are adopted as the distances RA and RB. In generalization, the smallest circles that are in contact with the bucket 1c with the shape change points A and B as the centers are drawn on the two-dimensional plane where the target shape appears, and the radii of the circles are adopted as the distances RA and RB. It is preferable. That is, in FIG. 9, the reference point of the distances RA and RB is P1, but another point on the bucket 1c may be used as the reference point, and the shortest point on the bucket from the shape change points A and B is the reference point. It is also good.

  In step S110, the angle αA (that is, two adjacent lines) formed by the line segment (n) included in the boundary L and the other line segment (n−1) connected at one end point A related to the line segment (n). The angle (angle formed by the line segment (n) and the line segment (n-1)) and the angle αB formed by the line segment (n) and the other line segment (n + 1) connected at the other end point B, and Proceed to S120. If point A or point B is the end of the target shape and no other line segment is connected, +90 degrees is set as αA or αB in step 110 (may be −90 degrees). With this configuration, excessive digging and empty digging near the end can be suppressed.

  The method of defining the “angle formed by two line segments” in the present embodiment is as follows. When the two adjacent line segments are designated as the first line segment and the second line segment from the one close to the hydraulic excavator, Is extended from the shape change point, and the angle formed by the extended line and the second line segment is defined as “the angle formed by the two line segments”. When the second line segment is positioned above the extended line, the sign of the angle is “positive”, and when it is opposite, the sign of the angle is “negative”. That is, the counterclockwise angle with respect to the extension line is “positive”, and the clockwise angle is “negative”. Therefore, for example, in the example of FIG. 9, the angle formed by the line segment (n−1) and the line segment n is “+ αA”, and the angle formed by the line segment n and the line segment (n + 1) is “−αB”. When the extension line and the second line segment overlap, the angle formed by the two line segments is 0, and the range of the angle formed by the two line segments is +90 degrees to −90 due to the nature of the excavation surface. Between degrees.

  In step S120, it is determined which of the two points A and B related to the boundary L is closest to the bucket 1c. Specifically, RA and RB are compared, and if RA <RB, the process proceeds to step S130, and if RA ≧ RB, the process proceeds to step S131.

  In step S130 and step S131, a process of selecting a distance R and an angle α to be used when calculating a deceleration coefficient K in step S150 described later is executed. Of these, in step S130, RA is set as R, and αA is set as α. Then, the process proceeds to step S140. On the other hand, in step S131, RB is set as R and αB is set as α, and the process proceeds to step S140. In the situation of FIG. 9, since RA <RB (that is, point A is the closest point), R = RA and α = αA. In step S140, the pilot that is output from the operation lever 4b indicates whether the operation direction of the bucket tip approaches or moves away from the nearest shape change point (point A in the situation of FIG. 9), that is, the arm cloud operation or the arm dump operation. Discriminate by pressure. The sign of the distance R is set to “positive” in the case of an approaching direction (arm cloud action), and the sign of the distance R is set to “negative” in the case of an approaching direction (arm dumping action). move on. In the situation of FIG. 9, the closest shape change point is point A, and it is determined that the movement is approaching when the arm cloud operation is performed, and the distance R is set to “+ RA”. Further, as a method of knowing the operation direction of the bucket tip, the direction of the vector calculated from the position change of the bucket tip may be used instead of using the pilot pressure as described above.

  In step S150, from R and α determined in step S130 or S131, referring to the tables of FIGS. 11 and 12, a distance coefficient Kd that changes according to the distance R and an angle coefficient that changes according to the angle α. Ka is obtained, and the deceleration coefficient K is calculated from the Kd and Ka and the following equation (3), and the process proceeds to step S160. Each of the distance coefficient Kd, the deceleration coefficient K, and the angle coefficient Ka is a value of 1 or less, and the arm cylinder speed upper limit value La is set smaller as these values become smaller (that is, the deceleration becomes larger). When the distance coefficient Kd or the angle coefficient Ka is 1, the deceleration coefficient K is 1 as will be apparent from equation (4) described later, and therefore the deceleration control according to the present invention is not performed.

  The table shown in FIG. 11 used when obtaining the distance coefficient Kd is defined so that the arm operation speed gradually changes as the distance R between the bucket 1c and the shape change point decreases. Such deceleration control prevents the operator's operability from being impaired. Specifically, in the case where the bucket 1c approaches the closest shape change point (when the distance R is positive), when the distance R reaches a set value (deceleration start distance Rs) or less, the coefficient increases as the distance R decreases. When Kd gradually decreases from 1 (maximum value) and then the distance R reaches a certain value less than the deceleration start distance, the coefficient Kd remains constant (minimum value) until the distance R reaches zero. Is set to

  On the other hand, when the bucket 1c moves away from the closest shape change point (when the distance R is negative), the coefficient Kd gradually increases from the minimum value as the distance R increases from zero, and the distance thereafter When R increases to a certain value, the coefficient Kd is set to maintain a constant value (maximum value = 1). In this way, in the case of an operation away from the shape change point, the speed is not reduced more than necessary, and further, the degree of deceleration is not changed abruptly so that a sense of incongruity does not occur in operability. .

  Note that the relationship between the distance R and the coefficient Kd shown in FIG. 11 is merely an example, and any other form may be used as long as the tendency that the coefficient Kd decreases as the distance R decreases.

  The table of FIG. 12 used when obtaining the angle coefficient Ka has a large angle α so that the degree of deceleration can be increased as the size of the angle α formed by the two line segments is larger (away from zero). The angle coefficient Ka is defined so as to gradually decrease as the height increases, so that an appropriate deceleration amount corresponding to the excavation shape can be determined. Further, in the present embodiment, the shoulder (negative angle) and the butt (positive angle) are discriminated based on the sign of the angle α, and the relationship between the coefficient Ka and the angle α is made different between the shoulder and the butt. ing. As in FIG. 11, the relationship between the angle α and the coefficient Ka shown in FIG. 12 is merely an example, and any other relationship can be used as long as the coefficient Ka tends to decrease as the angle α increases. An aspect may be sufficient.

  When the angle α determined in step S130 or step S131 is zero, the angle coefficient Ka is 1, and the deceleration control according to the present invention is not performed. The purpose of this configuration is that when the angle α is zero, the two line segments located on both sides of the closest shape change point form a flat surface, so there is no need to perform deceleration processing in the vicinity of the shape change point. Because. This situation occurs mainly when using a 3D construction drawing in which the target shape is defined by a polygon. When the target shape is cut along a vertical plane, the polygon is redefined and the shape changes on the flat surface. This often occurs due to the addition of points.

  In step S160, the arm cylinder speed upper limit value La is set based on the arm cylinder maximum speed stored in the storage device 20, the deceleration coefficient K calculated in step S150 and the following equation (4), and the process proceeds to step S170.

  In step S170, it is determined whether the arm cylinder estimated speed obtained by the arm cylinder estimated speed calculating unit 9d exceeds the arm cylinder speed upper limit value La determined in step S160. If it is determined that the arm cylinder estimated speed is exceeded, deceleration is required. Judge and proceed to step S180. On the other hand, if it is determined that the speed does not exceed, the process proceeds to step S181 assuming that deceleration is not performed, the arm cylinder estimated speed obtained by the arm cylinder estimated speed calculation unit 9d is set as it is as the arm cylinder target speed, and the process ends.

  In step S180, the arm cylinder speed upper limit value La calculated in step S160 is set as the arm cylinder target speed in place of the arm cylinder estimated speed obtained by the calculation unit 9d, and the process ends. That is, after step S180, the arm cylinder target speed is limited to the arm cylinder speed upper limit value La.

  Instead of the deceleration method using the above formula (4), even if the deceleration is performed by calculating the arm cylinder target speed by directly multiplying the estimated arm cylinder speed by the deceleration coefficient K as in the following formula (5). Good. Alternatively, as shown in the following formula (6), the arm pilot pressure may be multiplied by a deceleration coefficient and then the arm cylinder estimated speed may be calculated again to reduce the speed.

  Returning to FIG. 3, in the bucket tip speed calculation unit 9e by the arm, the arm cylinder target speed calculation unit 9z obtains the arm cylinder target speed obtained by the series of processes of FIG. 10 and the front working device 1A obtained by the front posture calculation unit 9a. The bucket tip speed b by the arm 1b is calculated based on the position and orientation of.

  In the limit value calculation unit 9f for the bucket tip speed by the boom, the bucket tip speed b by the arm 1b obtained by the calculation unit 9e is converted from the XY coordinate system to the XaYa coordinate system using the conversion data obtained by the region setting calculation unit 9b. , The bucket tip speed (bx, by) by the arm 1b is calculated, and the limit value a of the component perpendicular to the bucket tip speed boundary L obtained by the computing unit 9c and the component perpendicular to the bucket tip speed boundary L by the arm By, the limit value c of the component perpendicular to the boundary L of the bucket tip speed by the boom 1a is calculated. Next, this will be described with reference to FIG.

  In FIG. 6, the boundary between the limit value a of the component perpendicular to the bucket tip speed boundary L obtained by the bucket tip speed limit value calculation unit 9c and the bucket tip speed b by the arm obtained by the bucket tip speed calculation unit 9e by the arm. The difference (a-by) in the component by perpendicular to L is the limit value c of the component perpendicular to the boundary L of the bucket tip speed by the boom 1a. In the limit value calculator 9f of the bucket tip speed by the boom, "c = a The limit value c is calculated from the expression “−by”.

  Next, the meaning of the limit value c will be described separately when the bucket tip is in (A) the set area (excavable area), (B) on the boundary, and (C) outside the set area. To do.

  (A) When the bucket tip is within the set region, the bucket tip speed is limited to the limit value a of the component perpendicular to the bucket tip speed boundary L in proportion to the distance D from the bucket tip boundary L. . Accordingly, the component perpendicular to the boundary L of the bucket tip speed by the boom 1a is limited to c (= a−by). When the component by perpendicular to the boundary L of the bucket tip speed b exceeds a, the speed is reduced to a, and the limit value c of the bucket tip speed by the boom 1a becomes zero.

  (B) When the bucket tip is on the boundary L of the setting region, the limit value a of the component perpendicular to the bucket tip velocity boundary L is 0, and the boundary L of the bucket tip velocity b by the arm that goes outside the setting region The component by perpendicular to is canceled (made zero) by the correction operation by raising the boom with the limit value c, and the component bx parallel to the boundary L of the bucket tip speed remains (see FIGS. 7 and 8).

  (C) When the bucket tip is out of the region (when it is below the boundary L), the component perpendicular to the bucket tip speed boundary L is an upward limit value a proportional to the distance D from the bucket tip boundary L. As a result of the restriction, the correction operation is performed by raising the limit value c so as to always restore within the set area (see FIG. 8).

  Returning to FIG. 3, the boom cylinder speed limit value calculation unit 9g uses the conversion data based on the limit value c of the component perpendicular to the boundary L of the bucket tip speed by the boom 1a and the position and orientation of the front work apparatus 1A. The limit value of the boom cylinder speed is calculated by coordinate conversion.

  The boom pilot pressure (boom command) limit calculation unit 9h obtains a boom pilot pressure limit value corresponding to the boom cylinder speed limit value obtained by the calculation unit 9g based on the flow rate characteristics of the flow control valve 5a of the boom 1a. .

  In the arm pilot pressure (arm command) limit calculation unit 9j, based on the flow characteristics of the flow control valve 5b of the arm 1b, the arm pilot corresponding to the bucket tip speed b by the arm 1b obtained by the bucket tip speed calculation unit 9e by the arm Find the pressure limit.

  In the area limit control switching calculation section 9r, when the area limit switch 7 is ON (pressed) and the area limit control is selected (when permitted), the calculation section is used as the boom pilot pressure limit value. The value calculated at 9h is output as it is as the value calculated at 9h as the limit value of the arm pilot pressure. On the other hand, when the region restriction switch 7 is OFF (not pressed) and the region restriction control is not selected (prohibited), the larger value from the pilot pressure detected by the pressure detectors 60a and 60b. Is output as the limit value of the boom pilot pressure, and the larger one of the pilot pressures detected by the pressure detectors 61a and 61b is output as the limit value of the arm pilot pressure. In addition, when outputting the value detected by the detector 60b or the detector 61b, it shall output with a negative value.

  The boom valve command calculation unit 9i inputs the pilot pressure limit value from the area limit control switching calculation unit 9r. When this value is positive, the boom raising side proportional solenoid valve 10a corresponds to the limit value. Is output, the pilot pressure of the hydraulic drive unit 50a of the flow control valve 5a is corrected to the limit value, and a voltage of 0 is output to the proportional solenoid valve 10b on the boom lowering side to output the hydraulic drive unit of the flow control valve 5a. The pilot pressure of 50b is set to zero. Further, when the limit value is negative, the pilot pressure is corrected by outputting a voltage corresponding to the limit value to the proportional solenoid valve 10b so as to limit the pilot pressure of the hydraulic drive unit 50b of the flow control valve on the boom lowering side. Then, a voltage of 0 is output to the proportional solenoid valve 10a on the boom raising side, and the pilot pressure of the hydraulic drive unit 50a of the flow control valve 5a is set to 0.

  In the valve command calculation unit 9k, the limit value of the pilot pressure from the switching calculation unit 9r of the region limit control is input, and when this value is positive, the voltage corresponding to the limit value is applied to the proportional electromagnetic valve 11a on the arm dump side. , The pilot pressure of the hydraulic drive unit 51a of the flow control valve 5b is corrected to the limit value, a voltage of 0 is output to the proportional electromagnetic valve 11b on the arm cloud side, and the hydraulic drive unit 51b of the flow control valve 5b Set pilot pressure to zero. When the limit value is negative, the pilot pressure is corrected by outputting a voltage corresponding to the limit value to the proportional solenoid valve 11b so as to limit the pilot pressure of the hydraulic drive unit 51b of the flow control valve on the arm cloud side. Then, a voltage of 0 is output to the proportional electromagnetic valve 11b on the arm dump side, and the pilot pressure of the hydraulic drive unit 51a of the flow control valve 5a is set to 0.

  As described above, according to the present embodiment, when the bucket 1c approaches a certain shape change point, the arm cylinder speed is calculated by the arm cylinder target speed calculation unit 9z so that the upper limit value La (arm cylinder maximum speed × deceleration). Since the speed of the bucket 1c is sufficiently reduced by automatically reducing to the coefficient K), it is suppressed that the tip of the bucket 1c reaches the outside of the set region beyond the boundary L, and excessive digging near the shape change point or The occurrence of empty digging can be prevented.

  When the upper limit value La and the limit value a are compared at the same position in the vicinity of the shape change point, it is preferable to set the deceleration coefficient K so that the upper limit value La is smaller than the limit value a. For example, FIG. 13 shows an example in which the deceleration coefficient K is set so that the upper limit value La is smaller than the limit value a below the distance R1 near the shape change point (for the sake of simplicity, the angle coefficient Ka = 0). When the deceleration coefficient K is set in this manner, the bucket 1c is decelerated in the vicinity of the shape change point (the range less than the distance R1 in FIG. 13) than in the normal area restriction control, so the boundary L is automatically set according to the position of the bucket 1c. Even when the boundary changes near the shape change point by the selection process, the excavation speed is such that excessive digging or empty digging does not occur, and excavation along the target shape is facilitated. That is, even when the target shape is defined by a plurality of line segments, accurate area restriction control can be realized. Furthermore, even if the target shape is defined by a plurality of line segments, excavation in a continuous operation becomes easy, so that the construction efficiency can be improved.

  In addition, since the present embodiment requires relatively simple processing even in the calculation associated therewith, the control unit (computer) 9 can be compared with a method of calculating the target pilot pressure for each of a plurality of line segments. It is possible to suppress an increase in calculation load.

  In the flowchart of FIG. 10, distances RA and RB to two points (shape change points) A and B that define the line segment (n) included in the boundary L selected at that time are calculated and the points closer to each other are calculated. The deceleration coefficient K is calculated by using the distance (R) of the two and the angle (α) formed by the two line segments at the close point. Instead of this series of processing, a plurality of points (shapes) defining the target shape are calculated. The distance (R) from the change point) to the point closest to the bucket 1c, which is the tip of the work device 1A, is calculated, and the angle (α) formed by the two line segments connected at the closest point is calculated. May be.

  Further, in the above embodiment, the deceleration coefficient K is changed according to the distance R from the shape change point to the bucket 1c, so that the radius is a circle whose deceleration start distance Rs is centered on a certain shape change point. A decelerating region of the arm cylinder 3b is formed, but an arbitrary closed region (for example, a rectangle) instead of the circle is set as a decelerating region around a certain shape change point, and a bucket is placed in the region. If 1c enters, you may comprise so that an arm cylinder speed may be decelerated.

  In the above-described embodiment, the deceleration coefficient K is determined according to the distance R and the angle α. However, the deceleration coefficient may be determined using only one of them. However, if the deceleration coefficient K is determined only by the angle α, the speed is uniformly decelerated according to the angle α regardless of the distance R. Therefore, when approaching a predetermined distance (for example, the deceleration start distance Rs), the angle α is determined. From the viewpoint of work efficiency and operability, it is preferable to start to decelerate.

  In the above embodiment, when the bucket 1c approaches the shape change point, the arm cylinder 3b is decelerated to reduce the bucket speed. However, instead of / in addition to the arm cylinder 3b, the boom cylinder 3a and / or The bucket cylinder 3c may be decelerated.

  In the above description, the angle detectors 8a to 8c are used to acquire the position and orientation of the front working device 1A. Instead, a plurality of stroke detectors that detect the stroke amounts of the hydraulic cylinders 3a to 3c are used. Alternatively, a plurality of inclination angle detectors that detect the inclination angles of the boom 1a, the arm 1b, and the bucket 1c may be used.

  In the above embodiment, a general hydraulic excavator that drives a hydraulic pump with an engine is described as an example. However, a hybrid hydraulic excavator that drives a hydraulic pump with an engine and a motor, or a hydraulic pump with a motor. Needless to say, the present invention can also be applied to an electric hydraulic excavator or the like that is driven only by the motor.

  In addition, this invention is not limited to said embodiment, The various modifications within the range which does not deviate from the summary are included. For example, the present invention is not limited to the one having all the configurations described in the above embodiment, and includes a configuration in which a part of the configuration is deleted.

  DESCRIPTION OF SYMBOLS 1A ... Front work apparatus, 1B ... Vehicle body, 1a ... Boom, 1b ... Arm, 1c ... Bucket, 2 ... Hydraulic pump, 3a ... Boom cylinder (hydraulic actuator), 3b ... Arm cylinder (hydraulic actuator), 4a-4f, 14a ˜14f... Operation lever device (operation device), 5a to 5f, 15a to 15f... Flow control valve, 7... Restriction control switch, 8a to 8c. ... front posture calculation unit, 9b ... area setting calculation unit, 9c ... bucket tip speed limit value calculation unit, 9d ... arm cylinder estimated speed calculation unit, 9e ... bucket tip speed calculation unit by arm, 9f ... bucket tip speed by boom Limit value calculation unit, 9g ... boom cylinder speed limit value calculation unit, 9h ... boom pilot pressure calculation unit, 9i ... boom Valve command calculation unit, 9j ... arm pilot pressure calculation unit, 9k ... arm valve command calculation unit, 9r ... area limit control switching calculation unit, 9z ... arm cylinder target speed calculation unit, 10a, 10b, 11a, 10b ... Proportional solenoid valve, 12 ... shuttle valve, 20 ... storage device, 50a-55b ... hydraulic drive, 60a, 60b, 61a, 61b ... pressure detector

Claims (5)

An articulated working device configured by connecting a plurality of driven members;
A plurality of hydraulic actuators for respectively driving the plurality of driven members;
A plurality of operation devices for respectively instructing the operations of the plurality of hydraulic actuators according to the operation amount;
A plurality of flow rate control valves that are driven according to operation signals output according to operation amounts of the plurality of operation devices and that control flow rates and directions of hydraulic pressure supplied to the plurality of hydraulic actuators;
In a construction machine excavation control device comprising: a control device that executes region restriction control for controlling the working device to move in a region above and above a preset boundary surface;
The target shape by excavation work of the working device is defined by at least one line segment defined by two points,
The control device is configured to reduce the operation speed of at least one of the plurality of hydraulic actuators when a tip of the working device approaches one of the plurality of points defining the at least one line segment. A construction machine excavation control device characterized by correcting a signal. The construction machine excavation control device according to claim 1,
The control device adjusts the degree of deceleration of the at least one hydraulic actuator according to a distance from a point closest to the tip of the working device among the plurality of points to a tip of the working device. Excavation control device for construction machinery. The construction machine excavation control device according to claim 1,
The target shape is defined by a plurality of continuous line segments,
The control device adjusts a degree of deceleration of the at least one hydraulic actuator according to a size of an angle formed by two line segments adjacent to a point closest to the tip of the working device among the plurality of points. A construction machine excavation control device characterized by the above. In the construction machine excavation control device according to claim 3,
The control device adjusts so that the degree of deceleration of the at least one hydraulic actuator decreases as the angle formed by the two adjacent line segments approaches zero. apparatus. The hydraulic excavation control device for a construction machine according to any one of claims 1 to 4,
The excavation control device for a construction machine, wherein the control device adjusts a deceleration degree of the at least one hydraulic actuator based on an operation direction of a tip portion of the working device with respect to the closest point.

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