Patent Description:
For instance, Patent Literature <NUM> describes a conventional excavation control by a working machine. In Patent Literature <NUM>, a boom angle, an arm angle, and a slewing angle are calculated so that a coordinate of an arm distal end of a hydraulic backhoe and each excavation position agree with each other. Further, an angle of each of a boom, an arm, and a vehicle body is controlled to agree with the corresponding calculated value. What is described is that deviation in excavation positions from each other in a slewing direction leads to easy and efficient automatic excavation of a division having a larger range than a bucket width. Patent Literature <NUM> discloses a controller for an excavator having the features in the preamble of claim <NUM>. Patent Literature <NUM> discloses further prior art.

Under the excavation control described in Patent Literature <NUM>, the arm distal end is moved to reach a preset excavation position, and excavation is executed in determined order.

However, an excavation target has a shape or contour changing every moment in accordance with an excavation situation thereof. In this respect, the excavation control described in Patent Literature <NUM> fails to appropriately determine the excavation position in accordance with the shape or contour of the excavation target.

An object of the present invention is to provide an excavation position determination system that achieves appropriate determination of an excavation start position in accordance with a shape or contour of the excavation target.

The above object is solved by an excavation position determination system according to claim <NUM>.

The above object is also solved by an excavation control system according to claim <NUM>.

The above object is further solved by a working machine according to claim <NUM>.

Further advantageous embodiments are disclosed in the dependent claims.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the description below, a hydraulic excavator <NUM> is described as an example of a working machine.

The hydraulic excavator <NUM> can excavate an excavation target having, for example, a mountain shape. As shown in <FIG>, the hydraulic excavator <NUM> is a machine for performing a work with an attachment <NUM>, and includes a lower traveling body <NUM>, an upper slewing body <NUM> supported on the lower traveling body <NUM> slewaby about a slewing axis extending in an up-down direction, and the attachment <NUM>.

The lower traveling body <NUM> causes the hydraulic excavator <NUM> to travel, and has, for example, a crawler <NUM> travelable on the ground. The upper slewing body <NUM> is slewably attached onto the lower traveling body <NUM> via a slewing device <NUM>. The upper slewing body <NUM> has a cab <NUM> serving as an operator compartment on a front portion thereof. The lower traveling body <NUM> and the upper slewing body <NUM> form a machine body of the present invention.

The attachment <NUM> is attached to the upper slewing body <NUM> in a tiltable manner (rotatably in the up-down direction). The attachment <NUM> includes a boom <NUM>, an arm <NUM>, and a bucket <NUM>. The boom <NUM> has a proximal end attached to the upper slewing body <NUM>. The arm <NUM> has a proximal end attached to a distal end of the boom <NUM>. The bucket <NUM> is attached to a distal end of the arm <NUM>. The bucket <NUM> serves as a leading end attachment to execute works including excavation, leveling, and scooping of an excavation target having a mountain shape, such as a soil and sand mound <NUM> (see <FIG>). Here, the bucket <NUM> is movable relative to the machine body.

The hydraulic excavator <NUM> further includes a boom cylinder <NUM>, an arm cylinder <NUM>, and a bucket cylinder <NUM> (drive section) respectively driving the boom <NUM>, the arm <NUM>, and the bucket <NUM>. Each of the boom cylinder <NUM>, the arm cylinder <NUM>, and the bucket cylinder <NUM> is a hydraulic actuator. For instance, the boom cylinder <NUM> drives the boom <NUM> in a raising direction by extension and in a lowering direction by contraction. Each cylinder (drive section) can drive the bucket <NUM> relative to the upper slewing body <NUM>.

The hydraulic excavator <NUM> further includes a slewing angle sensor <NUM>, a boom angle sensor <NUM>, an arm angle sensor <NUM>, and a bucket angle sensor <NUM>.

The slewing angle sensor <NUM> detects a slewing angle of the upper slewing body <NUM> to the lower traveling body <NUM>. The slewing angle sensor <NUM> includes, for example, an encoder, a resolver, or a gyro sensor.

The boom angle sensor <NUM> is attached to the boom <NUM> to detect a posture of the boom <NUM>. The boom angle sensor <NUM> acquires a tilt angle of the boom <NUM> to a horizontal line. For example, a tilt sensor or an acceleration sensor is adopted as the boom angle sensor <NUM>. The boom angle sensor <NUM> may detect a rotation angle of a boom foot pin 10a (boom proximal end) to detect the posture of the boom <NUM>. Alternatively, the boom angle sensor <NUM> may detect a stroke amount of the boom cylinder <NUM> to detect the posture of the boom <NUM>.

The arm angle sensor <NUM> is attached to the arm <NUM> to detect a posture of the arm <NUM>. The arm angle sensor <NUM> acquires a tilt angle of the arm <NUM> to a horizontal line. For example, a tilt sensor or an acceleration sensor is adopted as the arm angle sensor <NUM>. The arm angle sensor <NUM> may detect a rotation angle of an arm connection pin 11a (arm proximal end) to detect the posture of the arm <NUM>. Alternatively, the arm angle sensor <NUM> may detect a stroke amount of the arm cylinder <NUM> to detect the posture of the arm <NUM>.

The bucket angle sensor <NUM> is attached to a link member <NUM> for driving the bucket <NUM> to detect a posture of the bucket <NUM>. The bucket angle sensor <NUM> acquires a tilt angle of the bucket <NUM> to a horizontal line. For example, a tilt sensor or an acceleration sensor is adopted as the bucket angle sensor <NUM>. The bucket angle sensor <NUM> may detect a rotation angle of a bucket connection pin 12a (bucket proximal end) to detect the posture of the bucket <NUM>. Alternatively, the bucket angle sensor <NUM> may detect a stroke amount of the bucket cylinder <NUM> to detect the posture of the bucket <NUM>.

A mobile terminal <NUM> shown in <FIG> is an external terminal manipulated by an operator or worker on a work site, and is, for example, a tablet terminal. The mobile terminal <NUM> is communicable with a controller <NUM> (start position determinator) to be described later. The mobile terminal <NUM> is arrangeable outside the hydraulic excavator <NUM> (at a position away from the hydraulic excavator <NUM>). The mobile terminal <NUM> can form a part of the excavation position determination system according to the present invention.

A photographing device <NUM> is attached to the hydraulic excavator <NUM>. Besides, the controller <NUM> is mounted on the hydraulic excavator <NUM>. In the embodiment, the photographing device <NUM> is attached to the front of the upper slewing body <NUM>. The controller <NUM> and the photographing device <NUM> form a part of the excavation position determination system according to the present invention.

The photographing device <NUM> photographs the soil and sand mound <NUM> (excavation target) and the bucket <NUM>. Although the photographing device <NUM> is attached to the hydraulic excavator <NUM> in the embodiment, the photographing device <NUM> may not be attached to the hydraulic excavator <NUM>. Specifically, the photographing device <NUM> may be arranged at such a position as to photograph the soil and sand mound <NUM>, and the bucket <NUM>, for example, in a periphery of the hydraulic excavator <NUM> or a periphery of a place where the soil and sand mound <NUM> is accumulated.

The photographing device <NUM> adopts, for example, a LIDAR, a laser radar, a millimeter-wave radar, or a stereo camera. The photographing device <NUM> may adopt a combination of the LIDAR and the camera.

The photographing device <NUM> can photograph various targets without limitation to the soil and sand mound <NUM> and the bucket <NUM>.

The controller <NUM> includes a computer which performs: input and output of a signal; computation including determination and calculation; and storage of information. As shown in <FIG>, a signal from each of the photographing device <NUM>, the boom angle sensor <NUM>, the arm angle sensor <NUM>, the bucket angle sensor <NUM>, and the slewing angle sensor <NUM> is input to the controller <NUM>. The controller <NUM> outputs a control signal to each of a boom operating device <NUM>, an arm operating device <NUM>, a bucket operating device <NUM>, and a slewing operating device <NUM>.

The boom operating device <NUM> controls the boom cylinder <NUM>. The boom operating device <NUM> is, for example, a hydraulic control device, and includes a direction control valve, a pressure control valve, and a flow rate control valve.

The arm operating device <NUM> controls the arm cylinder <NUM>. The arm operating device <NUM> is, for example, a hydraulic control device, and includes a direction control valve, a pressure control valve, and a flow rate control valve.

The bucket operating device <NUM> controls the bucket cylinder <NUM>. The bucket operating device <NUM> is, for example, a hydraulic control device, and includes a direction control valve, a pressure control valve, and a flow rate control valve.

The slewing operating device <NUM> controls the slewing device <NUM>. The slewing operating device <NUM> is, for example, a hydraulic control device, and includes a direction control valve, a pressure control valve, and a flow rate control valve.

The controller <NUM> (start position determinator) is configured to determine an excavation start position of the bucket <NUM> to the soil and sand mound <NUM>. The excavation start position represents a reference point where the bucket <NUM> starts an excavation operation for the soil and sand mound <NUM>, and, as an example, where the bucket <NUM> comes into contact with soil and sand of the soil and sand mound <NUM> from a state where the bucket <NUM> is arranged at an excavation start position when the boom <NUM> is driven in a lowering direction and the arm <NUM> is driven in a pulling direction. As described above, the excavation position determination system according to the present invention includes the photographing device <NUM> and the controller <NUM>. The controller <NUM> (target specifying section) can specify the bucket <NUM>, and the soil and sand mound <NUM> from photographed data of the photographing device <NUM>.

<FIG> is a diagram explaining a process of determining an excavation start position of the bucket <NUM>. <FIG> is illustration obtainable when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM>.

The controller <NUM> shifts the bucket <NUM> toward the soil and sand mound <NUM> in a slewing direction in the vicinity of ground G. The controller <NUM> causes the upper slewing body <NUM> to slew. The bucket <NUM> is positioned in the rear of the soil and sand mound <NUM> by the controller <NUM> when seen from the hydraulic excavator <NUM>. Here, the controller <NUM> can calculate a position and a posture of the bucket <NUM> from a signal from each of the angle sensors <NUM> to <NUM>. The controller <NUM> stores information about dimensions of respective members, i.e., the upper slewing body <NUM>, the boom <NUM>, the arm <NUM>, and the bucket <NUM>, in advance. The controller <NUM> controls the position and the posture of the bucket <NUM>.

The controller <NUM> determines, on the basis of the detected data from the photographing device <NUM>, a position of the bucket <NUM> where the bucket <NUM> is not wholly hidden by the soil and sand mound <NUM> but a part of the soil and sand mound <NUM> and a part of the bucket <NUM> overlap each other when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM> (machine body) as the excavation start position of the bucket <NUM> to the soil and sand mound <NUM>. In other words, the excavation start position represents a position of the bucket <NUM> where one part of the bucket <NUM> is visible from the machine body and other part of the bucket <NUM> that is different from the one part is hidden by the soil and sand mound <NUM> when the bucket <NUM> is seen from the machine body.

In the example shown in <FIG>, the controller <NUM> determines a position of the bucket <NUM> where a proportion of an area S of a certain part (the one part) of the bucket <NUM> that does not overlap the soil and sand mound <NUM> to a whole area of the bucket <NUM> is a predetermined value (proportion) or lower when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM> as the excavation start position.

For instance, the controller <NUM> calculates the whole area of the bucket <NUM> from point group data (detected data) of the bucket <NUM> acquired by the photographing device <NUM> when the bucket <NUM> is not hidden by the soil and sand mound <NUM> (as the bucket <NUM> denoted by a double-dotted line in <FIG>). The predetermined value (proportion) indicates, for example, <NUM>%.

When the bucket <NUM> is wholly hidden by the soil and sand mound <NUM>, some soil and sand is left without being excavated. By contrast, excavation is failed when the soil and sand mound <NUM>, and the bucket <NUM> do not overlap each other at all. The controller <NUM> (excavation position determination system) can automatically and appropriately determine an excavation start position in accordance with the shape or contour of the soil and sand mound <NUM>. In a subsequent excavation, the soil and sand mound <NUM> is efficiently excavated without being left. Moreover, when the bucket <NUM> is wholly hidden by the soil and sand mound <NUM>, a soil amount in the bucket <NUM> is undetectable in the excavation. The soil amount in the bucket <NUM> in the excavation is detectable by the photographing device <NUM> at an excavation position determined by the controller <NUM>, and therefore, an unnecessary excavation operation is preventable and the soil and sand is efficiently excavated through a scooping operation by the bucket <NUM> when a given amount of soil and sand or more is excavated.

Furthermore, the controller <NUM> determines the excavation start position of the bucket <NUM> by employing the proportion of the area S of the certain part of the bucket <NUM> that does not overlap the soil and sand mound <NUM> to the whole area of the bucket <NUM>, thereby reliably keeping the bucket <NUM> from being wholly hidden by the soil and sand mound <NUM> and preventing the bucket <NUM> and the soil and sand mound <NUM> from failing to overlap each other.

Here, the predetermined value (proportion) defined as, for example, <NUM> % may be directly input to the controller <NUM> or may be input to the controller <NUM> through the mobile terminal <NUM>, by the operator. Specifically, the operator may be allowed to correct the excavation start position by changing the predetermined value (proportion) through the mobile terminal <NUM>. The operator allowed to correct the excavation start position through the mobile terminal <NUM> can flexibly set the excavation start position from a place away from the hydraulic excavator <NUM>.

In addition, the controller <NUM> serves as a signal input section of the present invention as well. The signal input section inputs, to the drive section (each cylinder) of the hydraulic excavator <NUM>, a drive instructive signal to start an excavation operation for the soil and sand mound <NUM> by the bucket <NUM> from an excavation start position determined by the controller <NUM> (start position determinator). In this case, the photographing device <NUM> and the controller <NUM> form an excavation control system according to the present invention.

<FIG> is a diagram explaining another process, which is different from the process in <FIG>, of determining an excavation start position of the bucket <NUM>. <FIG> is illustration obtainable when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM>.

The controller <NUM> shifts the bucket <NUM> toward the soil and sand mound <NUM> in a slewing direction in the vicinity of the ground G. The controller <NUM> causes the upper slewing body <NUM> to slew. The bucket <NUM> is positioned in the rear of the soil and sand mound <NUM> by the controller <NUM>.

The controller <NUM> determines a position of the bucket <NUM> where a distance Y1 (offset distance) between an end Pe of the soil and sand mound <NUM> that is closer to the bucket <NUM> in a direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> and an end Pb1 of the bucket <NUM> in the opposite direction to the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> reaches a predetermined value (distance) or smaller when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM> as the excavation start position.

The end Pe is at a point on a lower corner which is closer to the bucket <NUM> among the point group data (detected data) of the soil and sand mound <NUM> acquired by the photographing device <NUM>. The end Pb1 is at a point on a lower corner which is away from the soil and sand mound <NUM> among the point group data (detected data) of the bucket <NUM> acquired by the photographing device <NUM>. The predetermined value (distance) indicates, for example, <NUM>.

Determination of the excavation start position of the bucket <NUM> by employing the distance Y1 (offset distance) between the end Pe of the soil and sand mound <NUM> that is closer to the bucket <NUM> in the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> and the end Pb1 of the bucket <NUM> in the opposite direction to the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> leads to a success in reliably keeping the bucket <NUM> from being wholly hidden by the soil and sand mound <NUM> and preventing the bucket <NUM> and the soil and sand mound <NUM> from failing to overlap each other.

Here, the predetermined value (distance) defined as, for example, <NUM> may be directly input to the controller <NUM> or may be input to the controller <NUM> through the mobile terminal <NUM>, by the operator. Specifically, the excavation start position may be correctable in accordance with a change in the predetermined value (distance) through the mobile terminal <NUM>. When the excavation start position is correctable through the mobile terminal <NUM>, the operator can flexibly set an excavation start position from a place away from the hydraulic excavator <NUM>.

In each of the cases shown in <FIG>, the controller <NUM> determines an excavation start position of the bucket <NUM> to the soil and sand mound <NUM> in a slewing direction of the upper slewing body <NUM> with respect to the lower traveling body <NUM>.

<FIG> is a diagram explaining a process of determining a first excavation start position and a second excavation start position in gradual deviation of the bucket <NUM> from each other in the slewing direction at each excavation when the soil and sand mound <NUM> is excavated. <FIG> is a plan view explaining a state of gradual deviation of excavation start positions from one another in a slewing direction.

The upper illustration in <FIG> is equivalent to the illustration in <FIG>, but shows the first excavation start position of the bucket <NUM>. The lower illustration in <FIG> shows the second excavation start position of the bucket <NUM>.

In <FIG>, the positions respectively denoted by the mark "∘" and given the reference signs B1 to B4 represent first to fourth excavation start positions of the bucket <NUM>. Double-dotted lined rectangle portions respectively denoted by the numerals (<NUM>) to (<NUM>) and adjacently overlapping each other in the slewing direction represent excavation ranges of the bucket <NUM> for first to fourth excavations. <FIG> further shows a three-dimensional rectangular coordinate system based on the hydraulic excavator <NUM>. A direction of approaching the soil and sand mound <NUM> from the hydraulic excavator <NUM> is denoted by an X-axial direction (X-axis). A Y-axis is perpendicular to the X-axis on a horizontal plane, and a Z-axis is perpendicular to both the X-axis and the Y-axis. The Z-axis extends in a vertical direction.

In the example shown in <FIG>, a way of determining the first excavation start position of the bucket <NUM> is the same as a way of determining the second excavation start position of the bucket <NUM>.

Specifically, the controller <NUM> shifts the bucket <NUM> toward the soil and sand mound <NUM> in the slewing direction in the vicinity of the ground G. The controller <NUM> determines, on the basis of the detected data from the photographing device <NUM>, a position of the bucket <NUM> where of the bucket <NUM> is not wholly hidden by the soil and sand mound <NUM> but a part of the soil and sand mound <NUM> and a part of the bucket <NUM> overlap each other as the first excavation start position of the bucket <NUM> to the soil and sand mound <NUM> (upper illustration in <FIG>).

Similarly, the controller <NUM> determines, on the basis of the detected data from the photographing device <NUM>, each of the second and subsequent excavation start position (lower illustration in <FIG>) so that the bucket <NUM> is not wholly hidden by the soil and sand mound <NUM> but a part of the soil and sand mound <NUM> and a part of the bucket <NUM> overlap each other.

That is to say, the controller <NUM> determines a position of the bucket <NUM> where one part of the bucket <NUM> is visible from the machine body and other part of the bucket <NUM> is hidden by the soil and sand mound <NUM> as the excavation start position in each of the first and second excavations. Here, the controller <NUM> deviates each of the second and subsequent excavation start positions from a preceding excavation start position in the slewing direction (Y-axial direction) of the bucket <NUM>.

The shape or contour of the soil and sand mound <NUM> changes every moment in accordance with an excavation situation thereof. This configuration enables automatic and appropriate determination of the excavation start position in accordance with the shape or contour of the soil and sand mound <NUM> in the second or subsequent excavation in addition to the first excavation.

Concerning determination of the excavation start position of the bucket <NUM>, in the examples shown in <FIG> and <FIG>, the controller <NUM> determines each of the first excavation start position, and second and subsequent excavation start positions of the bucket <NUM> by employing a distance Y1 (offset distance) between an end Pe of the soil and sand mound <NUM> that is closer to the bucket <NUM> in the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> and an end Pb1 of the bucket <NUM> in the opposite direction to the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> in the same manner as shown in <FIG>.

Alternatively, as shown in <FIG>, the controller <NUM> may determine each excavation start position of the bucket <NUM> by employing a proportion of an area S of a certain part of the bucket <NUM> that does not overlap the soil and sand mound <NUM> to the whole area of the bucket <NUM>.

The end Pb1 is at a point on a lower corner which is away from the soil and sand mound <NUM> among point group data (detected data) of the bucket <NUM> acquired by the photographing device <NUM>. The end Pb1 may be undetectable due to the soil and sand accumulated on the ground G. In this case, the controller <NUM> can calculate a coordinate of the end Pb <NUM> from an end Pb4 located above the end Pb1 and on an upper corner of the bucket <NUM> by using the dimension of the bucket <NUM> stored in the controller <NUM>.

Moreover, concerning the determination of each of the second and subsequent excavation start positions, the controller <NUM> may deviate the second and subsequent excavation start positions from one another each at a predetermined angle in the slewing direction of the bucket <NUM> per excavation. This predetermined angle takes a fixed value determined and input to the controller <NUM> by the operator without consideration of the detected data from the photographing device <NUM>. Even with the fixed value, the bucket <NUM> can be kept from being wholly hidden by the soil and sand mound <NUM>. Consequently, the soil and sand mound <NUM> is efficiently excavatable in a subsequent excavation. Further, a computation load of the controller <NUM> is suppressible.

The controller <NUM> controls the boom <NUM>, the arm <NUM>, and the bucket <NUM> to execute the first excavation after determining a first excavation start position B1 (see <FIG>). After the first excavation and soil discharge is finished, the bucket <NUM> is shifted in the slewing direction for determination of a second excavation start position B2, and the second excavation is executed. The controller <NUM> gradually deviates each excavation start position in the slewing direction per excavation. <FIG> is a plan view explaining a state of gradual deviation of excavation start positions from one another in the slewing direction. The excavation direction is represented by the X-axial direction in <FIG>, but, more accurately, the excavation direction indicates a direction of approaching the proximal end of the boom <NUM> of the hydraulic excavator <NUM>.

<FIG> is a plan view explaining a state of gradual deviation of excavation start positions from one another in a slewing direction. <FIG> is a flowchart explaining a flow of executions of counting an excavation number, i.e., excavation No., and changing, in accordance with the excavation No, the excavation start position by the controller <NUM>.

As shown in <FIG>, for example, a whole excavation range of the soil and sand mound <NUM> in the slewing direction is presumed as a range of -<NUM>° to <NUM>° in a view from the hydraulic excavator <NUM>.

The controller <NUM> may deviate the second and subsequent excavation start positions in the slewing direction of the bucket <NUM> in accordance with the excavation number input by the controller <NUM>.

Here, it is presumed that a specific excavation number, for instance, "<NUM>" is input as the excavation number "N" to the controller <NUM> as to how many excavations are required to excavate a whole range (whole excavation range) of the soil and sand mound <NUM> in the slewing direction. That is to say, the whole range of the soil and sand mound <NUM> in the slewing direction is supposed to be excavatable at five excavations in total.

As shown in <FIG>, the controller <NUM> determines the excavation number as "<NUM>", i.e., excavation No. = <NUM> (corresponding to step <NUM> as denoted by "S1" in <FIG>, and the same expression is adopted for other steps).

The controller <NUM> shifts the bucket <NUM> toward the soil and sand mound <NUM> in the slewing direction. The controller <NUM> determines, on the basis of the detected data from the photographing device <NUM>, a position of the bucket <NUM> where the bucket <NUM> is not wholly hidden by the soil and sand mound <NUM> but a part of the soil and sand mound <NUM> and a part of the bucket <NUM> overlap each other as the first excavation start position of the bucket <NUM> to the soil and sand mound <NUM> (step S2).

Subsequently, the controller <NUM> controls the boom <NUM>, the arm <NUM>, and the bucket <NUM> to excavate the soil and sand mound <NUM> (step S3).

Next, the controller <NUM> adds "<NUM>" to the excavation No. (step S4), and returns to step S2 when the excavation No. does not exceed "<NUM>" (No in step S5). Contrarily, when the excavation No. exceeds "<NUM>", that is, indicates N + <NUM> or larger (Yes in step S5), the controller <NUM> decides an end of excavation (step S6), and thus the excavation is finished.

In this regard, the second and subsequent excavation start positions are determined, for example, in the manner described below. The controller <NUM> equally divides, in the slewing direction, a residual range that is left from the whole excavation range (-<NUM>° to <NUM>°) of the soil and sand mound <NUM> after the first excavation, and gradually deviates excavation start positions at equal intervals (each at a predetermined angle or an equal phase difference) in the second and subsequent excavations. In other words, the controller <NUM> equally divides the range left after the first excavation by the remaining excavation number = <NUM> in the slewing direction.

Here, the operator may determine the excavation number under the condition that a part of an excavation range of the bucket in an n-th excavation and a part of an excavation range of the bucket in an (n+<NUM>)th excavation overlap each other, and the operator may input the determined excavation number to the controller <NUM>. Specifically, the controller <NUM> can receive an input of the excavation number to the soil and sand mound <NUM>, and can set the predetermined angle in accordance with the input excavation number so that the second and subsequent excavation start positions shift in the slewing direction.

The operator may input another excavation number to the controller <NUM> to change the excavation number, that is, to correct the excavation start position. Here, the operator may input the excavation number from the mobile terminal <NUM> to the controller <NUM>. Specifically, the excavation start position may be correctable through the mobile terminal <NUM> in accordance with the changed excavation number. In this case, the mobile terminal <NUM> is operable to input, to the controller <NUM>, a signal of correcting the excavation start position.

As described heretofore, the controller <NUM> enabling deviation of the excavation start positions in the slewing direction of the bucket <NUM> in accordance with the input excavation number allows the operator to input another excavation number to the controller <NUM> in accordance with the shape or contour of the soil and sand mound <NUM> to change the excavation number, and consequently permits the hydraulic excavator <NUM> to flexibly execute an excavation in accordance with the shape or contour of the soil and sand mound <NUM>.

<FIG> is a diagram explaining a process of determining an excavation start position in a modification in the present invention.

The example in <FIG> illustrates a state where the controller <NUM> shifts the bucket <NUM> toward the soil and sand mound <NUM> in the slewing direction in the vicinity of the ground G. By contrast, in the example shown in <FIG>, a controller <NUM> lowers a bucket <NUM> from a position above a soil and sand mound <NUM> to a rear position of the soil and sand mound <NUM> to arrange the bucket <NUM> at an excavation start position. In this case, the controller <NUM> moves an arm <NUM> in a lowering direction.

The controller <NUM> determines, on the basis of detected data from a photographing device <NUM>, a position of the bucket <NUM> where a proportion of an area S of a specific part of the bucket <NUM> that does not overlap the soil and sand mound <NUM> to a whole area of the bucket <NUM> is a predetermined value (proportion) or lower when the soil and sand mound <NUM> is seen from the hydraulic excavator <NUM> as the excavation start position.

The predetermined value (proportion) indicates, for example, <NUM>%. Here, the controller <NUM> deviates the second and subsequent excavation start positions downward from a preceding excavation start position.

<FIG> is a diagram explaining another process, which is different from the process in <FIG>, of determining an excavation start position in another modification in the present invention.

The controller <NUM> determines, on the basis of detected data from a photographing device <NUM>, a position of the bucket <NUM> where a distance Z1 (offset distance) between an end Pm of the soil and sand mound <NUM> that is closer to the bucket <NUM> in a direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> and an end Pb3 of the bucket <NUM> in the opposite direction to the direction of causing the bucket <NUM> to approach the soil and sand mound <NUM> reaches a predetermined value (distance) or smaller when the soil and sand mound <NUM> (bucket <NUM>) is seen from the hydraulic excavator <NUM> (machine body) as the excavation start position.

The predetermined value (distance) indicates, for example, <NUM>. Here, the controller <NUM> deviates the second and subsequent excavation start positions downward from a preceding excavation start position.

In each of the cases shown in <FIG>, the controller <NUM> determines the excavation start position of the bucket <NUM> to the soil and sand mound <NUM> in a tilting direction of the attachment <NUM> with respect to the upper slewing body <NUM>.

Heretofore, the embodiment and modifications of the present invention are described. Here, the embodiment and the modifications are further changeable in the manner described below.

The excavation target having the mountain shape may be a crushed stone mound, a scrap mound, or a rubber mound in place of the soil and sand mound <NUM>.

<FIG> and other drawings show that the bucket <NUM> is shifted toward the soil and sand mound <NUM> in the slewing direction in the vicinity of the ground G to determine an excavation start position of the bucket <NUM> to the soil and sand mound <NUM>. Alternatively, the bucket <NUM> may be arranged at a position above the ground G without exceeding the height of the top of soil and sand mound <NUM>, and the bucket <NUM> may be shifted from the position toward the soil and sand mound <NUM> in the slewing direction to determine the excavation start position of the bucket <NUM> to the soil and sand mound <NUM>.

The controller <NUM> mounted on the hydraulic excavator <NUM> does not necessarily store a computation system for determining an excavation start position of the bucket <NUM> to the soil and sand mound <NUM>. For instance, another controller (not shown) which is different from the controller <NUM> but communicable with the controller <NUM>, and further provided outside the hydraulic excavator <NUM> may store a computation system for determining an excavation start position of the bucket <NUM> to the soil and sand mound <NUM>.

Heretofore, the embodiment of the present invention is described. In addition, various changes are applicable to an extent conceivable by a person skilled in the art. The hydraulic excavator <NUM> (working machine) does not need to include all the components of each of the excavation position determination system and the excavation control system according to the present invention. For instance, a server provided in a remote management center located at a position away from a work site of the hydraulic excavator <NUM> may serve as the controller <NUM>.

The present invention provides an excavation position determination system for use in a working machine including a machine body and a bucket movable relative to the machine body for excavating an excavation target having a mountain shape. The excavation position determination system includes: a photographing device that photographs the excavation target and the bucket; and a start position determinator that determines an excavation start position of the bucket to the excavation target. The start position determinator determines, on the basis of detected data from the photographing device, a position of the bucket where a part of the bucket is visible from the machine body and the other part of the bucket is hidden by the excavation target when the bucket is seen from the machine body as the excavation start position.

In the configuration, the start position determinator may determine a position of the bucket where a proportion of an area of the one part of the bucket visible from the machine body to a whole area of the bucket is a predetermined value or lower when the bucket is seen from the machine body as the excavation start position.

In the configuration, the start position determinator may determine a position of the bucket where a distance between an end of the excavation target that is closer to the bucket in a direction of causing the bucket to approach the excavation target and an end of the bucket in the opposite direction to the direction of causing the bucket to approach the excavation target reaches a predetermined value or smaller when the bucket is seen from the machine body as the excavation start position.

In the configuration, when the working machine executes a plurality excavation works to the excavation target, the start position determinator may determine a position of the bucket where the part of the bucket is visible from the machine body and the other part of the bucket is hidden by the excavation target as a first excavation start position, and determine a position of the bucket where one part of the bucket is visible from the machine body and the other part of the bucket is hidden by the excavation target as a second or subsequent excavation start positions.

In the configuration, when the working machine executes a plurality of excavation works to the excavation target, the start position determinator determines a position of the bucket where the part of the bucket is visible from the machine body and the other part of the bucket is hidden by the excavation target as a first excavation start position, and determines second and subsequent excavation start positions in deviation from one another each at a predetermined angle.

In the configuration, the start position determinator is configured to receive an input of an excavation number to the excavation target and set the predetermined angle in accordance with the input excavation number so that the second and subsequent excavation start positions shift in a slewing direction.

The configuration may further include an external terminal arrangeable at a position away from the working machine and communicable with the start position determinator. The external terminal may be operable to input, to the start position determinator, a signal of correcting the excavation start position.

The present invention provides an excavation control system including: the excavation position determination system described above; and a signal input section that inputs a drive instructive signal to the working machine to start an excavation operation for the excavation target by the bucket from the excavation start position determined by the start position determinator of the excavation position determination system.

In addition, the present invention provides a working machine including: a machine body; a bucket that is movable relative to the machine body; a drive section that drives the bucket; and the excavation control system described above. The signal input section inputs the drive instructive signal to the drive section to start the excavation operation for the excavation target by the bucket from the excavation start position determined by the start position determinator of the excavation position determination system.

In the configuration, the machine body may include: a lower traveling body; an upper slewing body supported on the lower traveling body slewably about a slewing axis extending in an up-down direction; and an attachment including the bucket and tiltably supported on the upper slewing body. The start position determinator may determine the excavation start position of the bucket to the excavation target in a slewing direction of the upper slewing body with respect to the lower traveling body.

Claim 1:
An excavation position determination system for use in a working machine including a machine body and a bucket (<NUM>) movable relative to the machine body for excavating an excavation target (<NUM>) having a mountain shape, the excavation position determination system comprising:
a photographing device (<NUM>) that photographs the excavation target (<NUM>) and the bucket (<NUM>); and
a start position determinator (<NUM>) that determines an excavation start position of the bucket (<NUM>) to the excavation target (<NUM>), wherein
the start position determinator (<NUM>) determines, on the basis of detected data from the photographing device (<NUM>), a position of the bucket (<NUM>) where a part of the bucket (<NUM>) is visible from the machine body and the other part of the bucket (<NUM>) is hidden by the excavation target (<NUM>) when the bucket (<NUM>) is seen from the machine body as the excavation start position, characterized in that
when the working machine executes a plurality of excavation works to the excavation target (<NUM>), the start position determinator (<NUM>) determines a position of the bucket (<NUM>) where the part of the bucket (<NUM>) is visible from the machine body and the other part of the bucket (<NUM>) is hidden by the excavation target (<NUM>) as a first excavation start position, and determines second and subsequent excavation start positions in deviation from one another each at a predetermined angle,
wherein the start position determinator (<NUM>) is configured to receive an input of an excavation number to the excavation target (<NUM>) and set the predetermined angle in accordance with the input excavation number so that the second and subsequent excavation start positions shift in a slewing direction.