The present invention relates to a work machine.
As a work machine such as a hydraulic excavator, what has a machine control (hereinafter, described as MC as appropriate) function that assists operation of a front work device by an operator is known (refer to patent document 1). In patent document 1, area setting means that sets an area in which the tip of a bucket can move and an area limiting excavation controller that carries out deceleration control to reduce the movement velocity of an arm when the distance from a boundary of the set area (target surface) to the tip of the bucket becomes shorter than a predetermined threshold on the basis of the position and posture of the front work device are described.
In the technique described in patent document 1, in the case in which the distance from the target surface to the tip of the bucket is shorter than the predetermined threshold, the movement velocity of the arm is reduced also when entry of the bucket into the target surface is not envisaged. Therefore, there is a fear of the lowering of the efficiency of work by the work machine.
The present invention aims at improving the efficiency of work by a work machine.
A work machine according to one aspect of the present invention includes a machine body, an articulated work device that has a boom, an arm, and work equipment and is attached to the machine body, an operation device that operates the machine body and the work device, a position sensor that senses the position of the machine body, and a posture sensor that senses posture of the work device. The work machine includes also a controller that sets a target surface, and calculates a work equipment-to-target surface distance that is a distance from the work equipment to the target surface on the basis of signals from the position sensor and the posture sensor, and controls the boom and carries out deceleration control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when operation of the arm is carried out by the operation device and the work equipment-to-target surface distance has become shorter than a predetermined distance. The controller is configured to determine whether or not there is a possibility that the work equipment enters the target surface when operation of the arm is carried out, on the basis of the target surface that is set and the signals from the position sensor and the posture sensor, and the controller is configured not to carry out the deceleration control even when the work equipment-to-target surface distance is shorter than the predetermined distance in the case in which it is determined that there is no possibility that the work equipment enters the target surface.
According to the present invention, the efficiency of work by a work machine can be improved.
Embodiments of the present invention will be described below by using the drawings. In the following, a hydraulic excavator including a bucket 10 as work equipment (attachment) at the tip of a work device will be exemplified. However, the present invention may be applied to a work machine including an attachment other than the bucket. Moreover, application to a work machine other than the hydraulic excavator is also possible as long as the work machine is what includes an articulated work device having a boom, an arm, and work equipment.
Furthermore, in the present specification, regarding the meaning of a word, “on,” “upper side,” and “lower side,” used with a term showing a certain shape (for example, target surface, design surface, or the like), “on” means the “surface” of this certain shape, and “upper side” means a “position higher than the surface” of this certain shape, and “lower side” means a “position lower than the surface” of this certain shape. Moreover, in the following description, when plural elements exist as the same constituent elements, alphabets are often given to the tail ends of characters (numerals). However, these alphabets are omitted and these plural constituent elements are collectively represented in some cases. For example, when three pumps 300a, 300b, and 300c exist, they are collectively represented as pumps 300.
—Overall Configuration of Hydraulic Excavator—
As illustrated in
In the work device 1A, plural driven members (boom 8, arm 9, and bucket 10) that are each pivoted in the perpendicular direction are joined in series. The base end part of the boom 8 is pivotally supported at the front part of the upper swing structure 12 with the interposition of a boom pin 91. The arm 9 is pivotally joined to the tip part of the boom 8 with the interposition of an arm pin 92 and the bucket 10 as work equipment is pivotally joined to the tip part of the arm 9 with the interposition of a bucket pin 93. The boom 8 is driven by a hydraulic cylinder (hereinafter, represented also as boom cylinder 5) that is an actuator. The arm 9 is driven by a hydraulic cylinder (hereinafter, represented also as arm cylinder 6) that is an actuator. The bucket 10 is driven by a hydraulic cylinder (hereinafter, represented also as bucket cylinder 7) that is an actuator.
A boom angle sensor 30 is attached to the boom pin 91 and an arm angle sensor 31 is attached to the arm pin 92 and a bucket angle sensor 32 is attached to a bucket link 13 such that pivot angles α, β, and γ (see
In a cab 16 disposed in the upper swing structure 12, an operation device 48 (
In the upper swing structure 12, an engine 18 (see
A lock valve 39 is disposed on a pump line 170 that is a delivery line of the pilot pump 19. The downstream side of the lock valve 39 in the pump line 170 is made to branch into plural lines and these lines are connected to the operation devices 44 to 49 and the respective valves in the hydraulic unit 160 for controlling the work device 1A. The lock valve 39 is a solenoid selector valve in the present example and an electromagnetic drive part thereof is electrically connected to a position sensor of a gate lock lever (not illustrated) disposed in the cab 16 of the upper swing structure 12. The position of the gate lock lever is sensed by the position sensor and a signal according to the position of the gate lock lever is input from the position sensor to the lock valve 39. When the position of the gate lock lever exists at a lock position, the lock valve 39 closes and the pump line 170 is interrupted. When the position of the gate lock lever exists at a lock release position, the lock valve 39 opens and the pump line 170 opens. That is, in the state in which the pump line 170 is interrupted, operation by the operation devices 44 to 49 is disabled and operation of swing, excavation, and so forth is prohibited.
The operation devices 44 to 49 each include a pair of pressure reducing valves of a hydraulic pilot system. These operation devices 44 to 49 use the delivery pressure of the pilot pump 19 as the source pressure to generate a pilot pressure (often referred to as operation pressure) according to the operation amount (for example, lever stroke) and the operation direction of the operation levers 22 and 23 each operated by an operator. The pilot pressure thus generated is supplied to hydraulic drive parts 150a to 155b of corresponding flow control valves 15a to 15f in a control valve unit 20 through pilot lines 144a to 149b and is used as a control signal to drive these flow control valves 15a to 15f.
A hydraulic fluid delivered from the main pump 2 is supplied to the boom cylinder 5, the arm cylinder 6, the bucket cylinder 7, the swing hydraulic motor 4, the travelling right hydraulic motor 3a, and the travelling left hydraulic motor 3b through the flow control valves 15a to 15f. The boom cylinder 5, the arm cylinder 6, and the bucket cylinder 7 extend and contract by the supplied hydraulic fluid. Due to this, the boom 8, the arm 9, and the bucket 10 are each pivoted and the position of the bucket 10 and the posture of the work device 1A are changed. The swing hydraulic motor 4 is rotated by the supplied hydraulic fluid and thereby the upper swing structure 12 is swung relative to the lower track structure 11. The travelling right hydraulic motor 3a and the travelling left hydraulic motor 3b rotate by the supplied hydraulic fluid and thereby the lower track structure 11 travels.
The posture of the work device 1A can be defined based on an excavator-based coordinate system of
The length from the center position of the boom pin 91, which joins the upper swing structure 12 and the boom 8, to the center position of the arm pin 92, which joins the boom 8 and the arm 9, is defined as L1. The length from the center position of the arm pin 92 to the center position of the bucket pin 93, which joins the arm 9 and the bucket 10, is defined as L2. The length from the center position of the bucket pin 93 to the tip part of the bucket 10 (for example, claw tip of the bucket 10) is defined as L3. In this case, the position of the tip part of the bucket 10 in the excavator-based coordinates (hereinafter, represented as tip position Pb) can be represented by the following expressions (1) and (2), with Xbk being the X-direction position and Zbk being the Z-direction position.
Xbk=L1 cos(α)+L2 cos(α+β)+L3 cos(α+β+γ) expression (1)
Zbk=L1 sin(α)+L2 sin(α+β)+L3 sin(α+β+γ) expression (2)
Similarly, a center position Pp of the arm pin 92 in the excavator-based coordinates can be represented by the following expressions (3) and (4), with Xp being the X-direction position and Zp being the Z-direction position.
Xp=L1 cos(α) expression (3)
Zp=L1 sin(α) expression (4)
Furthermore, as illustrated in
A control system 21 that carries out machine guidance (Machine Guidance: MG) and machine control (Machine Control: MC) will be described with reference to
In this control system 21, the MC that causes the work device 1A to operate according to a condition defined in advance when at least one of the operation devices 44, 45, and 46 is operated is carried out. Control of the hydraulic actuator (5, 6, 7) in the MC is carried out by forcibly outputting a control signal (for example, to extend the boom cylinder 5 to forcibly make boom raising action) to the relevant flow control valve 15a, 15b, or 15c. As the MC carried out in this control system 21, “ground leveling control (area limiting control)” carried out when arm operation is carried out by the operation device 45 and “stop control” carried out when boom lowering operation is carried out without carrying out arm operation are included.
The ground leveling control (area limiting control) is the MC to control at least one of the hydraulic actuators 5, 6, and 7 in such a manner that the work device 1A is located on a predetermined target surface St (see
The stop control is the MC to stop boom lowering action to keep the tip part of the bucket 10 from entering the lower side relative to the target surface St. In the stop control, the controller 40 gradually decelerates boom lowering action as the tip part of the bucket 10 approaches the target surface St in boom lowering operation.
In the present embodiment, a control point of the work device 1A at the time of the MC is set to the claw tip of the bucket 10 of the hydraulic excavator 101. However, the control point can be changed also to a point other than the claw tip of the bucket 10 as long as it is a point on the tip part of the work device 1A. For example, the bottom surface of the bucket 10 or the outermost part of the bucket link 13 may be set as the control point. Furthermore, a configuration in which the point on the bucket 10 closest to the target surface St is set as the control point as appropriate may be employed. In the MC, there are “automatic control” in which operation of the work device 1A is controlled by the controller 40 at the time of non-operation of the operation devices 44, 45, and 46 and “semiautomatic control” in which operation of the work device 1A is controlled by the controller only at the time of operation of the operation device 44, 45, or 46. The MC is referred to also as “intervention control” because control by the controller 40 intervenes in operator operation.
Furthermore, as the MG of the work device 1A in this control system 21, for example, as illustrated in
As illustrated in
The posture sensor 50 has the boom angle sensor 30 attached to the boom 8, the arm angle sensor 31 attached to the arm 9, the bucket angle sensor 32 attached to the bucket 10, and the machine body inclination angle sensor 33 attached to the machine body 1B. These angle sensors (30, 31, 32, and 33) acquire information relating to the posture of the work device 1A and output a signal according to the information. That is, the angle sensors (30, 31, 32, and 33) function as a posture sensor that senses the posture of the work device 1A. For example, as the angle sensors 30, 31, and 32, potentiometers that acquire the boom angle, the arm angle, and the bucket angle as the information relating to the posture and output a signal (voltage) according to the acquired angle can be employed. Furthermore, as the machine body inclination angle sensor 33, an IMU (Inertial Measurement Unit: inertial measurement device) that acquires the angular velocities and the accelerations of orthogonal three axes as the information relating to the posture and calculates the inclination angle θ on the basis of this information to output a signal that represents the inclination angle θ to the controller 40 can be employed. The controller 40 may carry out the calculation of the inclination angle θ on the basis of an output signal of the IMU.
The target surface setting device 51 is a device that can input, to the controller 40, information relating to the target surface St (position information of one target surface or plural target surfaces, information on the inclination angle of the target surface with respect to a reference plane (horizontal plane), and so forth). The target surface setting device 51 is connected to an external terminal (not illustrated) in which three-dimensional data of target surfaces defined on the global coordinate system (absolute coordinate system) is stored. The input of the target surface through the target surface setting device 51 may be manually carried out by the operator.
The operator operation sensor 52a has pressure sensors 70a, 70b, 71a, 71b, 72a, and 72b (see
As illustrated in
As illustrated in
Furthermore, the hydraulic unit 160 includes a solenoid proportional valve 55a that is disposed on the pilot line 145a and reduces the pilot pressure (first control signal) in the pilot line 145a on the basis of the control signal from the controller 40 to output the resulting pressure to the hydraulic drive part 151a of the flow control valve 15b and a solenoid proportional valve 55b that is disposed on the pilot line 145b and reduces the pilot pressure (first control signal) in the pilot line 145b on the basis of the control signal from the controller 40 to output the resulting pressure to the hydraulic drive part 151b of the flow control valve 15b.
Moreover, the hydraulic unit 160 includes solenoid proportional valves 56a and 56b that are disposed on the pilot lines 146a and 146b and reduce the pilot pressure (first control signal) in the pilot lines 146a and 146b on the basis of the control signal from the controller 40 to output the resulting pressure, solenoid proportional valves 56c and 56d that have the primary port side connected to the pilot pump 19 through the pump line 170 and reduce the pilot pressure from the pilot pump 19 to output the resulting pressure, and shuttle valves 83a and 83b that are connected to the pilot lines 146a and 146b of the operation device 46 for the bucket 10 and the secondary port side of the solenoid proportional valves 56c and 56d and select the higher pressure side of the pilot pressure in the pilot line 146a or 146b and the control pressure output from the solenoid proportional valve 56c or 56d to introduce the higher pressure side to the hydraulic drive part 152a or 152b of the flow control valve 15c.
In the solenoid proportional valves 54b, 55a, 55b, 56a, and 56b, the degree of opening is the maximum at the time of non-energization and the degree of opening becomes lower as a current that is the control signal from the controller 40 is increased. On the other hand, in the solenoid proportional valves 54a, 56c, and 56d, the degree of opening is the minimum (for example, 0 (zero)) at the time of non-energization and the degree of opening becomes higher as a current that is the control signal from the controller 40 is increased. As above, the degree of opening of the solenoid proportional valves 54, 55, and 56 becomes what depends on the control signal from the controller 40.
In the hydraulic unit 160 configured as above, when the control signal is output from the controller 40 and the solenoid proportional valves 54a, 56c, and 56d are driven, the pilot pressure (second control signal) can be generated even in the case in which operator operation to the corresponding operation device 44 or 46 is not made. Therefore, boom raising action, bucket crowding action, and bucket dumping action can be forcibly carried out. Furthermore, similarly to this, when the solenoid proportional valves 54b, 55a, 55b, 56a, and 56b are driven by the controller 40, the pilot pressure (second control signal) obtained by reducing the pilot pressure (first control signal) generated through operator operation to the operation device 44, 45, or 46 can be generated, and the velocity of boom lowering action, arm crowding/dumping action, and bucket crowding/dumping action can be forcibly reduced from the value of the operator operation.
In the present specification, in the control signals to the flow control valves 15a to 15c, the pilot pressure generated by operation of the operation device 44, 45, or 46 is referred to as the “first control signal.” Furthermore, in the control signals to the flow control valves 15a to 15c, the pilot pressure generated through driving the solenoid proportional valve 54b, 55a, 55b, 56a, or 56b by the controller 40 and correcting (reducing) the first control signal and the pilot pressure newly generated separately from the first control signal through driving the solenoid proportional valve 54a, 56c, or 56d by the controller 40 are referred to as the “second control signal.”
The second control signal is generated when the velocity of the control point of the work device 1A (in the present embodiment, tip part of the bucket 10) generated by the first control signal goes against a predetermined condition and is generated as a control signal that generates the velocity of the control point of the work device 1A that does not go against this predetermined condition. When the first control signal is generated for one hydraulic drive part in the same flow control valve 15a to 15c and the second control signal is generated for the other hydraulic drive part, the second control signal is allowed to preferentially act on the hydraulic drive part. Thus, the first control signal is interrupted by the solenoid proportional valve and the second control signal is input to the other hydraulic drive part. Therefore, in the flow control valves 15a to 15c, one for which the second control signal is calculated is controlled based on the second control signal, and one for which the second control signal is not calculated is controlled based on the first control signal, and one for which neither the first nor second control signal is generated is not controlled (driven). When the first control signal and the second control signal are defined as described above, it can also be said that the MC is control of the flow control valves 15a to 15c based on the second control signal.
As illustrated in
The controller 40 illustrated in
In the controller 40, the ground leveling control mode is set by the control mode changeover switch or the like that is not illustrated in the diagram as described above. When the distance H1 between the bucket 10 and the target surface St has become shorter than a predetermined distance defined in advance, the ground leveling control (area limiting control) is carried out.
When the ground leveling control mode is set, the controller 40 sets the target surface St and calculates the bucket-to-target surface distance H1 that is the distance from the bucket 10 to the target surface St on the basis of signals from the GNSS antennas 14 and the angle sensors 30 to 33. Furthermore, when operation of the arm 9 is carried out by the operation device 45 and the bucket-to-target surface distance H1 has become shorter than a predetermined distance Ya, the controller 40 controls the boom 8 and carries out deceleration control to decelerate the arm 9 to keep the bucket 10 from excavating the ground beyond the target surface St.
Here, if the deceleration control to decelerate the arm 9 is carried out across the board when the bucket-to-target surface distance H1 is shorter than the predetermined distance Ya, the deceleration control is carried out also in the case in which there is no need to decelerate the arm 9, for example, the case in which entry of the bucket 10 into the target surface (that is, excavation of the ground beyond the target surface St by the bucket 10) is not envisaged from the posture of the work device 1A and the positional relation between the work device 1A and the target surface St. Thus, there is a fear of the lowering of the work efficiency.
Thus, the controller 40 according to the present embodiment is configured to determine whether or not there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out based on the set target surface St and signals from the GNSS antennas 14 and the angle sensors 30 to 33 and not to carry out the deceleration control of the arm 9 even when the bucket-to-target surface distance H1 is shorter than the predetermined distance Ya in the case in which it is determined that there is no possibility that the bucket 10 enters the target surface St. Functions of the controller 40 will be described in detail below.
The operation amount calculating section 43a computes the operation amount of the operation devices 44, 45, and 46 (operation levers 22a and 22b) on the basis of signals from the operator operation sensor 52a (i.e. signals that represent sensed values of the pressure sensors 70, 71, and 72). The operation amount of boom raising operation that is operation for causing the boom 8 to make raising action is computed from the sensed value of the pressure sensor 70a. The operation amount of boom lowering operation that is operation for causing the boom 8 to make lowering action is computed from the sensed value of the pressure sensor 70b. The operation amount of arm crowding (arm pulling) operation that is operation for causing the arm 9 to make crowding action is computed from the sensed value of the pressure sensor 71a. The operation amount of arm dumping (arm pushing) operation that is operation for causing the arm 9 to make dumping action is computed from the sensed value of the pressure sensor 71b. The operation amounts thus converted from the sensed values of the pressure sensors 70, 71, and 72 are output to the target velocity calculating section 43d. Furthermore, although diagrammatic representation in
The computation method of the operation amount is not limited to the case in which the operation amount is computed based on the sensing result of the pressure sensor 70, 71, or 72. For example, a position sensor (for example, rotary encoder) that senses rotational displacement of the operation lever of the respective operation devices 44, 45, and 46 may be disposed as an operation sensor and the operation amount of the relevant operation lever may be computed based on the sensing result of this position sensor.
The target surface setting section 43c sets the target surface St on the basis of information from the target surface setting device 51. Specifically, the target surface setting section 43c calculates position information of the target surface St on the basis of the information from the target surface setting device 51 and stores it in the RAM 64. In the present embodiment, as illustrated in
As illustrated in
Moreover, the posture calculating section 43b calculates various kinds of data (H1, H2, Dpb, φ) that represent the positional relation between the target surface St and the work device 1A on the basis of the target surface St set by the target surface setting section 43c, a signal (information relating to the position of the machine body 1B) from the GNSS antennas 14, a signal (information relating to the angle) from the posture sensor 50, and the geometric information (L1, L2, L3) of the work device 1A stored in the storing device. These calculations will be described in detail below with reference to
As illustrated in
In the following, with use of the character n for discrimination of the respective target surfaces, plural target surfaces St(n) will be described. The above-described closest target surface St is represented as St(0) (i.e. St(n), n=0). Furthermore, the target surface that exists on the far side relative to the closest target surface St(0) as viewed from the machine body 1B is represented also as the far-side target surface St(n) and n is a positive integer that is equal to or larger than 1 and sequentially increments one by one as the target surface becomes farther from that closest to the closest target surface St(0). That is, the target surface on the far side closest to the closest target surface St(0) is the far-side target surface St(1) and the next closest target surface on the far side is the far-side target surface St(2). On the other hand, the target surface that exists on the near side relative to the closest target surface St(0) as viewed from the machine body 1B is represented also as the near-side target surface St(n) and n is a negative integer that is equal to or smaller than −1 and sequentially decrements one by one as the target surface becomes farther from that closest to the closest target surface St(0). That is, the target surface on the near side closest to the closest target surface St(0) is the near-side target surface St(−1) and the next closest target surface on the near side is the near-side target surface St(−2).
In the example illustrated in
The posture calculating section 43b calculates a pin-to-target surface distance H2(n) that is the shortest distance from the center position Pp (Xp, Zp) of the arm pin 92 to the target surface St(n) on the basis of the set target surface St, the signals from the GNSS antennas 14 and the posture sensor 50, and the geometric information of the work device 1A stored in the storing device. The posture calculating section 43b, when a perpendicular line can be drawn to the target surface St(n) from the center position Pp of the arm pin 92, calculates the length of the perpendicular line as the pin-to-target surface distance H2(n). The posture calculating section 43b, when it is impossible to draw a perpendicular line to the target surface St(n) from the center position Pp of the arm pin 92, calculates the shorter length in the lengths of line segments, which link the center position Pp of the arm pin 92 with both end positions of the target surface St(n), as the pin-to-target surface distance H2(n).
In the example illustrated in
The posture calculating section 43b calculates the shortest distance (linear distance) from the center position Pp (Xp, Zp) of the arm pin 92 to the tip position Pb (Xbk, Zbk) of the bucket 10 as the pin-to-bucket distance Dpb on the basis of the signal from the posture sensor 50 and the geometric information of the work device 1A stored in the storing device. The pin-to-bucket distance Dpb is equivalent to the length of a line segment Lpb that links the center position Pp with the tip position Pb.
The posture calculating section 43b calculates the line segment Lpb, which links the center position Pp (Xp, Zp) of the arm pin 92 with the tip position Pb (Xbk, Zbk) of the bucket 10, and an angle φ(n) formed by the line segment Lpb and the target surface St(n) on the basis of the set target surface St, the signals from the GNSS antennas 14 and the posture sensor 50, and the geometric information of the work device 1A stored in the storing device. Hereinafter, the angle formed by the line segment Lpb and the target surface St(n) is represented also as the angle φ(n) simply. In the present embodiment, the angle φ(n) refers to the angle formed by a straight line Lp parallel to the line segment Lpb and the target surface St(n) on the side of the machine body 1B relative to the straight line Lp when the straight line Lp is positioned on the target surface St(n) as illustrated in the diagram.
As illustrated in
The target velocity calculating section 43d calculates the target velocity of the respective hydraulic cylinders 5, 6, and 7 on the basis of the calculation result in the posture calculating section 43b and the calculation result in the operation amount calculating section 43a. The target velocity calculating section 43d calculates the target velocity of the respective hydraulic cylinders 5, 6, and 7 in such a manner that the lower side of the target surface St is kept from being excavated by the work device 1A in the ground leveling control (area limiting control). Detailed description will be made below with reference to
The target velocity calculating section 43d calculates the target velocity (primary target velocity) of the respective hydraulic cylinders 5, 6, and 7 on the basis of the operation amount of the operation devices 44, 45, and 46 calculated by the operation amount calculating section 43a. Next, the target velocity calculating section 43d calculates a target velocity vector Vc of the tip part of the bucket 10 illustrated in
In the direction conversion control, for example, as illustrated in
There is the case in which the direction conversion control is carried out based on a combination of boom raising or boom lowering and arm crowding, and there is the case in which the direction conversion control is carried out based on a combination of boom raising or boom lowering and arm dumping. In either case, when the target velocity vector Vc includes such a downward component as to get closer to the excavation target surface St (Vcy<0), the target velocity calculating section 43d calculates the target velocity of the boom cylinder 5 in the boom raising direction that cancels out the downward component. Conversely, when the target velocity vector Vc includes such an upward component as to get farther away from the excavation target surface St (Vcy>0), the target velocity calculating section 43d calculates the target velocity of the boom cylinder 5 in the boom lowering direction that cancels out the upward component.
When a mode in which the ground leveling control (area limiting control) is not carried out is set by the control mode changeover switch that is not illustrated in the diagram, the target velocity calculating section 43d outputs the target velocity of the respective hydraulic cylinders 5 to 7 according to the operation of the operation devices 44 to 46.
As illustrated in
Here, the target pilot pressure for the flow control valve 15b that controls action of the arm cylinder 6 is equivalent to a target value of a pilot pressure (second control signal) generated by reducing a pilot pressure (first control signal) output from the operation device 45 when the operation lever 22b of the operation device 45 of the arm 9 is operated to the maximum, for example.
Thus, when the secondary target velocity lower than the primary target velocity calculated based on the operation amount (maximum operation amount) of the arm 9 by the operator is set by the target velocity calculating section 43d, the target pilot pressure calculating section 43e sets the target pilot pressure lower than the pilot pressure output from the operation device 45. As a result, the solenoid proportional valve 55 is operated by a control signal from the valve command calculating section 43g to be described later and the pilot pressure (first control signal) output from the operation device 45 is reduced by the solenoid proportional valve 55, thus the pilot pressure (second control signal) is generated. Due to this, the arm 9 makes action at velocity lower than the velocity according to the operation amount (for example, maximum operation amount) of the operator regarding the operation device 45. That is, in the controller 40 according to the present embodiment, the deceleration control to decelerate the arm 9 can be carried out with intervention in operation by the operator when a predetermined condition holds.
The intervention deactivation calculating section 43f decides whether or not to carry out the deceleration control of the arm 9 with intervention in operation by the operator. In other words, the intervention deactivation calculating section 43f decides whether or not to deactivate the deceleration control of the arm 9 carried out with intervention in operation by the operator to the operation device 45 of the arm 9. The intervention deactivation calculating section 43f determines whether or not a condition to deactivate intervention in operation by the operator (deceleration control of the arm 9) (hereinafter, represented as intervention deactivation condition) holds, on the basis of the calculation result in the operation amount calculating section 43a, the calculation result in the posture calculating section 43b, and the target surface St set in the target surface setting section 43c.
When the intervention deactivation condition does not hold, the intervention deactivation calculating section 43f decides not to deactivate the deceleration control of the arm 9. In this case, the intervention deactivation calculating section 43f outputs the target pilot pressure calculated in the target pilot pressure calculating section 43e (target pilot pressure to the flow control valve 15b) to the valve command calculating section 43g as it is. On the other hand, when the intervention deactivation condition holds, the intervention deactivation calculating section 43f corrects the target pilot pressure calculated in the target pilot pressure calculating section 43e (target pilot pressure to the flow control valve 15b) to a maximum pressure Pmax and outputs it to the valve command calculating section 43g.
When the maximum pressure Pmax is set as the target pilot pressure to the flow control valve 15b of the arm cylinder 6, the solenoid proportional valve 55 becomes the fully-opened state due to the control signal from the valve command calculating section 43g to be described later. That is, when the operation lever 22b of the operation device 45 of the arm 9 is operated to the maximum, the pilot pressure (maximum pressure Pmax) output from the operation device 45 acts on the flow control valve 15b as it is without being reduced. Due to this, the arm 9 makes action at the velocity according to the operation amount (for example, maximum operation amount) of the operator regarding the operation device 45.
The intervention deactivation calculating section 43f outputs the target pilot pressures to the flow control valves 15a and 15c calculated in the target pilot pressure calculating section 43e to the valve command calculating section 43g as they are irrespective of whether or not holding of the intervention deactivation condition is necessary.
In the present embodiment, the intervention deactivation condition holds when any of the following (condition 1) and (condition 2) is satisfied, and does not hold when neither (condition 1) nor (condition 2) is satisfied.
(Condition 1) The bucket-to-target surface distance H1 is equal to or longer than the predetermined distance Ya.
(Condition 2) There is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out.
In the ground leveling control, it is preferable that the deceleration control of the arm 9 is carried out only when the distance between the tip part of the bucket 10 and the target surface St is short and the deceleration control of the arm 9 is not carried out when the distance between the tip part of the bucket 10 and the target surface St is somewhat long. This can improve the work efficiency of the work device 1A in the ground leveling control.
In the present embodiment, the intervention deactivation calculating section 43f determines that the intervention deactivation condition does not hold when the bucket-to-target surface distance H1 is shorter than the predetermined distance Ya, and determines that the intervention deactivation condition holds when the bucket-to-target surface distance H1 is equal to or longer than the predetermined distance Ya. The predetermined distance Ya is a threshold for determining whether or not the tip part of the bucket 10 is located near the target surface St and is stored in the storing device of the controller 40 in advance. In the present embodiment, Ya1 is stored in the storing device as the threshold Ya used when arm crowding operation is carried out and a threshold Ya2 is stored in the storing device as the threshold Ya used when arm dumping operation is carried out. The threshold Ya1 and the threshold Ya2 may be values identical to each other or may be different values.
In the ground leveling control, it is preferable that the deceleration control of the arm 9 is not carried out when it is determined that there is no possibility that the bucket 10 enters the target surface St due to operation of the arm 9 even when the bucket-to-target surface distance H1 is shorter than the predetermined distance Ya. This can improve the work efficiency of the work device 1A in the ground leveling control. Thus, in the present embodiment, the intervention deactivation calculating section 43f determines whether or not the posture of the work device 1A is such a posture that the bucket 10 enters the target surface St when operation of the arm 9 is carried out (hereinafter, represented as entry posture). When it is determined that the posture of the work device 1A is not the entry posture, the intervention deactivation calculating section 43f determines that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out. When it is determined that the posture of the work device 1A is the entry posture, the intervention deactivation calculating section 43f determines that there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out.
In the present embodiment, the intervention deactivation calculating section 43f executes processing of determining whether or not the posture of the work device 1A is the entry posture (first entry posture determination processing) on the basis of the pin-to-bucket distance Dpb and the pin-to-target surface distance H2 calculated in the posture calculating section 43b. The first entry posture determination processing is equivalent to processing of determining whether or not there is a possibility that the bucket 10 enters the target surface St (first bucket entry determination processing) by discriminating whether or not the target surface St exists on the movement locus of the tip part of the bucket 10 when operation of the arm 9 is carried out.
In the present embodiment, for example, in the ground leveling control, when arm crowding operation is carried out, the pilot pressure (second control signal) is generated in the solenoid proportional valve 54a and boom raising action is carried out. On the other hand, boom lowering action is not carried out unless the operator carries out operation. Therefore, on the premise that boom lowering operation is not carried out by the operator, if the pin-to-target surface distance H2 is equal to or longer than the pin-to-bucket distance Dpb, it can be determined that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, and it can be said that the posture of the work device 1A at the time is not the entry posture.
Thus, the intervention deactivation calculating section 43f according to the present embodiment determines that the posture of the work device 1A is not the entry posture when the pin-to-target surface distance H2 is equal to or longer than the pin-to-bucket distance Dpb, and determines that the posture of the work device 1A is the entry posture when the pin-to-target surface distance H2 is shorter than the pin-to-bucket distance Dpb.
Moreover, the intervention deactivation calculating section 43f executes processing of determining whether or not the posture of the work device 1A is the entry posture (second entry posture determination processing) on the basis of the angle φ calculated in the posture calculating section 43b. The second entry posture determination processing is equivalent to processing of determining whether or not there is a possibility that the bucket 10 enters the target surface St (second bucket entry determination processing) by discriminating whether the bucket 10 moves in such a direction as to get closer to the target surface St or moves in such a direction as to get farther away from the target surface St when operation of the arm 9 is carried out.
When arm crowding operation is carried out in the case in which the angle φ is larger than 90°, the tip part of the bucket 10 moves in such a direction as to get farther away from the target surface St that exists in the travelling direction of the bucket 10 (direction toward the near side as viewed from the machine body 1B). Thus, it can be determined that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, and it can be said that the posture of the work device 1A at the time is not the entry posture. When arm crowding operation is carried out in the case in which the angle φ is smaller than 90°, the tip part of the bucket 10 moves in such a direction as to get closer to the target surface St that exists in the travelling direction of the bucket 10 (direction toward the near side as viewed from the machine body 1B). Thus, it can be determined that there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, and it can be said that the posture of the work device 1A at the time is the entry posture.
When arm dumping operation is carried out in the case in which the angle φ is larger than 90°, the tip part of the bucket 10 moves in such a direction as to get closer to the target surface St that exists in the travelling direction of the bucket 10 (direction toward the far side as viewed from the machine body 1B). Thus, it can be determined that there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, and it can be said that the posture of the work device 1A at the time is the entry posture. When arm dumping operation is carried out in the case in which the angle φ is smaller than 90°, the tip part of the bucket 10 moves in such a direction as to get farther away from the target surface St that exists in the travelling direction of the bucket 10 (direction toward the far side as viewed from the machine body 1B). Thus, it can be determined that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, and it can be said that the posture of the work device 1A at the time is not the entry posture.
Thus, when the angle φ is equal to or larger than 90°, the intervention deactivation calculating section 43f according to the present embodiment determines that the posture of the work device 1A is not the entry posture with which the bucket 10 enters the target surface St when arm crowding operation is carried out. Furthermore, when the angle φ is smaller than 90°, the intervention deactivation calculating section 43f determines that the posture of the work device 1A is the entry posture with which the bucket 10 enters the target surface St when arm crowding operation is carried out. Moreover, the intervention deactivation calculating section 43f, when the angle φ is smaller than 90°, determines that the posture of the work device 1A is not the entry posture with which the bucket 10 enters the target surface St when arm dumping operation is carried out. Furthermore, the intervention deactivation calculating section 43f, when the angle φ is equal to or larger than 90°, determines that the posture of the work device 1A is the entry posture with which the bucket 10 enters the target surface St when arm dumping operation is carried out.
The second entry posture determination processing is based on the premise that combined operation of lowering operation of the boom 8 and operation of the arm 9 is not being carried out similarly to the first entry posture determination processing. Thus, it is preferable that, when combined operation of lowering operation of the boom 8 and operation of the arm 9 is being carried out, the intervention deactivation calculating section 43f determines there is a possibility that the bucket 10 enters the target surface St even when the posture of the work device 1A is not the entry posture. That is, it is preferable that the intervention deactivation calculating section 43f determines that (condition 2) is not satisfied.
That is, in the present embodiment, (condition 2) holds when the following (a1) or (b1) is satisfied, and does not hold when neither (a1) nor (b1) is satisfied.
(a1) Combined operation of lowering operation of the boom 8 and operation of the arm 9 is not being carried out and it is determined that the posture of the work device 1A is not the entry posture in the first entry posture determination processing.
(b1) Combined operation of lowering operation of the boom 8 and operation of the arm 9 is not being carried out and it is determined that the posture of the work device 1A is not the entry posture in the second entry posture determination processing.
When a configuration is made in which an image to make an instruction to carry out only arm operation without carrying out boom lowering operation is displayed on the display device 53a by the MG or the boom lowering operation is disabled when the ground leveling control mode is set by the control mode changeover switch, whether or not holding of condition (2) is necessary may be determined depending on whether or not the work posture is the entry posture irrespective of whether or not combined operation of boom lowering operation and arm operation is being carried out.
That is, in this case, (condition 2) holds when the following (a2) or (b2) is satisfied, and does not hold when neither (a2) nor (b2) is satisfied.
(a2) It is determined that the posture of the work device 1A is not the entry posture in the first entry posture determination processing.
(b2) It is determined that the posture of the work device 1A is not the entry posture in the second entry posture determination processing.
The valve command calculating section 43g, in order to cause the target pilot pressures output from the intervention deactivation calculating section 43f to act on the respective flow control valves 15a, 15b, and 15c, calculates electrical signals to be output to the solenoid proportional valves 54, 55, and 56 and outputs the calculated electrical signals (excitation currents) to the solenoid proportional valves 54, 55, and 56. The solenoids of the solenoid proportional valves 54, 55, and 56 are excited by the electrical signals (excitation currents) output from the valve command calculating section 43g. Thereby, the solenoid proportional valves 54, 55, and 56 are actuated and the pilot pressures that act on the flow control valves 15a, 15b, and 15c are controlled to the target pilot pressures set in the intervention deactivation calculating section 43f.
Therefore, when operation (full operation) of the arm 9 is being carried out in the state in which the ground leveling control mode is set and in the case in which the intervention deactivation condition does not hold, control in which the pilot pressure as the first control signal is reduced by the solenoid proportional valve 55 and the pilot pressure as the second control signal is generated, i.e. the deceleration control in which the arm 9 is controlled at velocity lower than the velocity according to the operation by the operator, is carried out. In other words, in the case in which the ground leveling control mode is set, when the bucket-to-target surface distance H1 becomes the state of being shorter than the predetermined distance Ya defined in advance from the state of being longer than the predetermined distance Ya due to action of the arm 9 through operation of the operation lever 22b to the maximum by the operator, the velocity of the arm 9 is controlled to be reduced if (condition 2) does not hold. On the other hand, in the case in which the ground leveling control is being carried out and the intervention deactivation condition holds, the solenoid proportional valve 55 is set to the opened state (in the present embodiment, fully-opened state), thus the arm 9 is controlled at the velocity according to operation by the operator. That is, the deceleration control of the arm 9 is not carried out and the state in which the deceleration control is deactivated is made.
Moreover, in the present embodiment, the determination processing of whether or not holding of the intervention deactivation condition is necessary is not executed only regarding the closest target surface St but executed regarding the target surface St that exists in the travelling direction of the bucket 10 when operation of the arm 9 is carried out. With reference to flowcharts of
As illustrated in
After the processing of setting the target surfaces St(n) in the work range as the calculation subjects (S105) is completed, the controller 40 executes loop processing in which a series of processing from a step S120 to a step S170 or a step S180 is repeatedly executed (steps S110 and S190). The step S110 represents the start of the loop and the step S190 represents the end of the loop. This loop processing (steps S110 and S190) ends when the intervention deactivation flag Fc(n) has been set regarding all of the target surfaces St(n), (n=m to 0) set as the calculation subjects. Upon the end of the loop processing, progress to a step S195 is made.
In the step S120, the intervention deactivation calculating section 43f determines whether or not arm crowding operation is being carried out, on the basis of a calculation result in the operation amount calculating section 43a. The intervention deactivation calculating section 43f, when an operation amount Ac of arm crowding calculated in the operation amount calculating section 43a is equal to or larger than a threshold Ac0, determines that arm crowding operation is being carried out, and progress to the step S130 is made. The intervention deactivation calculating section 43f, when the arm crowding operation amount Ac calculated in the operation amount calculating section 43a is smaller than the threshold Ac0, determines that arm crowding operation is not being carried out, and progress to the step S135 is made. The threshold Ac0 is a threshold for determining whether or not arm crowding operation is being carried out and is stored in the storing device of the controller 40 in advance.
In the step S130, the intervention deactivation calculating section 43f determines whether or not boom lowering operation is being carried out, on the basis of a calculation result in the operation amount calculating section 43a. The intervention deactivation calculating section 43f, when an operation amount Bl of boom lowering calculated in the operation amount calculating section 43a is equal to or larger than a threshold Bl0, determines that boom lowering operation is being carried out, and progress to the step S155 is made. The intervention deactivation calculating section 43f, when the boom lowering operation amount Bl calculated in the operation amount calculating section 43a is smaller than the threshold Bl0, determines that boom lowering operation is not being carried out, and progress to the step S135 is made. The threshold Bl0 is a threshold for determining whether or not boom lowering operation is being carried out and is stored in the storing device of the controller 40 in advance.
In the step S135, the posture calculating section 43b calculates the pin-to-target surface distance H2(n) and the pin-to-bucket distance Dpb, and progress to the step S140 is made. In the step S140, the intervention deactivation calculating section 43f determines whether or not the pin-to-target surface distance H2(n) calculated in the posture calculating section 43b is equal to or longer than the pin-to-bucket distance Dpb calculated in the posture calculating section 43b.
When it is determined in the step S140 that the pin-to-target surface distance H2(n) is equal to or longer than the pin-to-bucket distance Dpb, i.e. when it is determined that the posture of the work device 1A is not the entry posture and there is no possibility that the bucket 10 enters the target surface St(n) due to arm crowding operation, progress to the step S180 is made. When it is determined in the step S140 that the pin-to-target surface distance H2(n) is shorter than the pin-to-bucket distance Dpb, i.e. when it is determined that the posture of the work device 1A is the entry posture and there is a possibility that the bucket 10 enters the target surface St(n) due to arm crowding operation, progress to the step S145 is made.
In the step S145, the posture calculating section 43b calculates the angle φ(n), and progress to the step S150 is made. In the step S150, the intervention deactivation calculating section 43f determines whether or not the angle φ(n) calculated in the posture calculating section 43b is equal to or larger than 90°.
When it is determined in the step S150 that the angle φ(n) is equal to or larger than 90°, i.e. when it is determined that the posture of the work device 1A is not the entry posture and there is no possibility that the bucket 10 enters the target surface St(n) due to arm crowding operation, progress to the step S180 is made. When it is determined in the step S150 that the angle φ(n) is smaller than 90°, i.e. when it is determined that the posture of the work device 1A is the entry posture and there is a possibility that the bucket 10 enters the target surface St(n) due to arm crowding operation, progress to the step S155 is made.
In the step S155, the posture calculating section 43b calculates the bucket-to-target surface distance H1(n), and progress to the step S160 is made. In the step S160, the intervention deactivation calculating section 43f determines whether or not the bucket-to-target surface distance H1(n) calculated in the posture calculating section 43b is shorter than the threshold Ya1. When it is determined in the step S160 that the distance H1(n) is shorter than the threshold Ya1, progress to the step S170 is made. When it is determined that the distance H1(n) is equal to or longer than the threshold Ya1, progress to the step S180 is made.
In the step S170, the intervention deactivation calculating section 43f determines that the intervention deactivation condition does not hold (in other words, arm crowding deceleration condition holds), and sets the intervention deactivation flag Fc(n) to 0 (Fc(n)=0). Then, progress to the step S190 is made to end the series of processing regarding the relevant target surface St(n).
In the step S180, the intervention deactivation calculating section 43f determines that the intervention deactivation condition holds (in other words, arm crowding deceleration condition does not hold), and sets the intervention deactivation flag Fc(n) to 1 (Fc(n)=1). Then, progress to the step S190 is made to end the series of processing regarding the relevant target surface St(n).
When the loop processing is completed, progress to the step S195 is made and target pilot pressure output processing is executed. In the step S195, the intervention deactivation calculating section 43f determines whether or not all of the intervention deactivation flags Fc(n), (n=m to 0) are set to Fc(n)=1, and outputs the target pilot pressure on the basis of the determination. When it is determined that all of the intervention deactivation flags Fc(n) are not set to Fc(n)=1, i.e. when even one of the intervention deactivation flags Fc(n), (n=m to 0) is determined to be set to Fc(n)=0, the intervention deactivation calculating section 43f outputs, to the valve command calculating section 43g, the target pilot pressure for the hydraulic drive part 151a of the flow control valve 15b calculated in the target pilot pressure calculating section 43e as it is. Due to this, the deceleration control of the arm 9 is carried out and arm crowding action is carried out at velocity lower than the velocity according to operation by the operator.
On the other hand, when it is determined that all of the intervention deactivation flags Fc(n), (n=m to 0) are set to Fc(n)=1, the intervention deactivation calculating section 43f sets the maximum pressure Pmax as the target pilot pressure for the hydraulic drive part 151a of the flow control valve 15b irrespective of the calculation result in the target pilot pressure calculating section 43e and outputs the maximum pressure Pmax to the valve command calculating section 43g. Due to this, the solenoid proportional valve 55a capable of controlling arm crowding action is controlled to the fully-opened state. That is, the deceleration control of the arm 9 is not carried out. As a result, arm crowding action is carried out at the velocity according to operation by the operator. When the target pilot pressure output processing (S195) ends, the processing illustrated in the flowchart of
As illustrated in
After the processing of setting the target surfaces St(n) in the work range as the calculation subjects (S205) is completed, the controller 40 executes loop processing in which a series of processing from a step S220 to a step S270 or a step S280 is repeatedly executed (steps S210 and S290). The step S210 represents the start of the loop and the step S290 represents the end of the loop. This loop processing (steps S210 and S290) ends when the intervention deactivation flag Fd(n) has been set regarding all of the target surfaces St(n), (n=0 to q) set as the calculation subjects. Upon the end of the loop processing, progress to a step S295 is made.
In the step S220, the intervention deactivation calculating section 43f determines whether or not arm dumping operation is being carried out, on the basis of a calculation result in the operation amount calculating section 43a. The intervention deactivation calculating section 43f, when an operation amount Ad of arm dumping calculated in the operation amount calculating section 43a is equal to or larger than a threshold Ad0, determines that arm dumping operation is being carried out, and progress to the step S230 is made. The intervention deactivation calculating section 43f, when the arm dumping operation amount Ad calculated in the operation amount calculating section 43a is smaller than the threshold Ad0, determines that arm dumping operation is not being carried out, and progress to the step S235 is made. The threshold Ad0 is a threshold for determining whether or not arm dumping operation is being carried out and is stored in the storing device of the controller 40 in advance.
In the step S230, processing similar to the step S130 is executed. When it is determined in the step S230 that boom lowering operation is being carried out, progress to the step S255 is made. When it is determined that boom lowering operation is not being carried out, progress to the step S235 is made.
In the step S235, the posture calculating section 43b calculates the pin-to-target surface distance H2(n) and the pin-to-bucket distance Dpb, and progress to the step S240 is made. In the step S240, the intervention deactivation calculating section 43f determines whether or not the pin-to-target surface distance H2(n) calculated in the posture calculating section 43b is equal to or longer than the pin-to-bucket distance Dpb calculated in the posture calculating section 43b.
When it is determined in the step S240 that the pin-to-target surface distance H2(n) is equal to or longer than the pin-to-bucket distance Dpb, i.e. when it is determined that the posture of the work device 1A is not the entry posture and there is no possibility that the bucket 10 enters the target surface St(n) due to arm dumping operation, progress to the step S280 is made. When it is determined in the step S240 that the pin-to-target surface distance H2(n) is shorter than the pin-to-bucket distance Dpb, i.e. when it is determined that the posture of the work device 1A is the entry posture and there is a possibility that the bucket 10 enters the target surface St(n) due to arm dumping operation, progress to the step S245 is made.
In the step S245, the posture calculating section 43b calculates the angle φ(n), and progress to the step S250 is made. In the step S250, the intervention deactivation calculating section 43f determines whether or not the angle φ(n) calculated in the posture calculating section 43b is smaller than 90°.
When it is determined in the step S250 that the angle φ(n) is smaller than 90°, i.e. when it is determined that the posture of the work device 1A is not the entry posture and there is no possibility that the bucket 10 enters the target surface St(n) due to arm dumping operation, progress to the step S280 is made. When it is determined in the step S250 that the angle φ(n) is equal to or larger than 90°, i.e. when it is determined that the posture of the work device 1A is the entry posture and there is a possibility that the bucket 10 enters the target surface St(n) due to arm dumping operation, progress to the step S255 is made.
In the step S255, the posture calculating section 43b calculates the bucket-to-target surface distance H1(n), and progress to the step S260 is made. In the step S260, the intervention deactivation calculating section 43f determines whether or not the bucket-to-target surface distance H1(n) calculated in the posture calculating section 43b is shorter than the threshold Ya2. When it is determined in the step S260 that the distance H1(n) is shorter than the threshold Ya2, progress to the step S270 is made. When it is determined that the distance H1(n) is equal to or longer than the threshold Ya2, progress to the step S280 is made.
In the step S270, the intervention deactivation calculating section 43f determines that the intervention deactivation condition does not hold (in other words, arm dumping deceleration condition holds), and sets the intervention deactivation flag Fd(n) to 0 (Fd(n)=0). Then, progress to the step S290 is made to end the series of processing regarding the relevant target surface St(n).
In the step S280, the intervention deactivation calculating section 43f determines that the intervention deactivation condition holds (in other words, arm dumping deceleration condition does not hold), and sets the intervention deactivation flag Fd(n) to 1 (Fd(n)=1). Then, progress to the step S290 is made to end the series of processing regarding the relevant target surface St(n).
When the loop processing is completed, progress to the step S295 is made and target pilot pressure output processing is executed. In the step S295, the intervention deactivation calculating section 43f determines whether or not all of the intervention deactivation flags Fd(n), (n=0 to q) are set to Fd(n)=1, and outputs the target pilot pressure on the basis of the determination result. When it is determined that all of the intervention deactivation flags Fd(n) are not set to Fd(n)=1, i.e. when even one of the intervention deactivation flags Fd(n), (n=0 to q) is determined to be set to Fd(n)=0, the intervention deactivation calculating section 43f outputs, to the valve command calculating section 43g, the target pilot pressure for the hydraulic drive part 151b of the flow control valve 15b calculated in the target pilot pressure calculating section 43e as it is. Due to this, the deceleration control of the arm 9 is carried out and arm dumping action is carried out at velocity lower than the velocity according to operation by the operator.
On the other hand, when it is determined that all of the intervention deactivation flags Fd(n), (n=0 to q) are set to Fd(n)=1, the intervention deactivation calculating section 43f sets the maximum pressure Pmax as the target pilot pressure for the hydraulic drive part 151b of the flow control valve 15b irrespective of the calculation result in the target pilot pressure calculating section 43e and outputs the maximum pressure Pmax to the valve command calculating section 43g. Due to this, the solenoid proportional valve 55b capable of controlling arm dumping action is controlled to the fully-opened state. That is, the deceleration control of the arm 9 is not carried out. As a result, arm dumping action is carried out at the velocity according to operation by the operator. When the target pilot pressure output processing (S295) ends, the processing illustrated in the flowchart of
A specific example of operation of the work device 1A and a specific example of whether or not execution of the deceleration control is possible according to the posture of the work device 1A will be described with reference to
As illustrated in
In the present embodiment, when combined operation of lowering operation of the boom 8 and operation of the arm 9 is not being carried out, if it is determined that the posture of the work device 1A is not the entry posture, i.e. if it is determined that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, the target pilot pressure for the flow control valve 15b is set to the maximum pressure and the degree of opening of the solenoid proportional valve 55 becomes fully-opened.
When operation of the arm 9 is not being carried out (when the target pilot pressure is calculated as the minimum value), the degree of opening of the solenoid proportional valve 55 is set to the minimum degree of opening in the case in which it is determined that the posture of the work device 1A is the entry posture (that is, it is determined that there is a possibility that the bucket 10 enters the target surface when operation of the arm 9 is carried out) in each the first entry posture determination processing and the second entry posture determination processing and it is determined that the bucket-to-target surface distance H1(n) is shorter than the predetermined distance Ya (for example, N in S120 in
When the arm 9 is not being operated, the degree of opening of the solenoid proportional valve 55 is set to the maximum degree of opening (fully-opened) in the case in which it is determined that the posture of the work device 1A is not the entry posture (for example, N in S120 in
When plural target surfaces St(n) are set as illustrated in
Therefore, there is no need to execute various kinds of calculation processing for determining whether or not there is a possibility of entry of the bucket 10 regarding all of the set plural target surfaces St(n). Thus, the load of the calculation by the controller 40 can be reduced.
Furthermore, in the setting processing of the intervention deactivation flag Fc(n) for arm crowding, regarding the target surfaces St(n), (n=−3, −2, −1, 0) that are the target surfaces existing in the maximum work range of the bucket 10 and exist in the travelling direction of the bucket 10 when arm crowding operation is carried out, it is determined whether or not there is a possibility that the bucket 10 enters the target surface St(n), (n=−3, −2, −1, 0) when arm crowding operation is carried out. Similarly, in the setting processing of the intervention deactivation flag Fd(n) for arm dumping, regarding the target surfaces St(n), (n=0, 1) that are the target surfaces existing in the maximum work range of the bucket 10 and exist in the travelling direction of the bucket 10 when arm dumping operation is carried out, it is determined whether or not there is a possibility that the bucket 10 enters the target surface St(n), (n=0, 1) when arm dumping operation is carried out.
In the case in which it is determined whether or not there is a possibility of entry of the bucket 10 due to operation of the arm 9 only regarding the closest target surface St(0), there is a fear that shock attributed to a transition of the state between the deceleration control state (state in which the deceleration control is being carried out) and the deactivation state of the deceleration control (state in which the deceleration control is not being carried out) occurs when the closest target surface St(0) is switched to the adjacent target surface St(1) or St(−1). In contrast, the controller 40 according to the present embodiment determines whether or not there is a possibility of entry of the bucket 10 regarding not only the closest target surface St(0) but the target surface St(n) set in the direction in which the bucket 10 travels. Then, on the basis of the determination result, the controller 40 decides whether to carry out the deceleration control or not to carry out it (to deactivate the deceleration control). In the present embodiment, the deceleration control of the arm 9 is carried out when the bucket-to-target surface distance H1(n) is shorter than the threshold Ya and even one target surface St(n) involving a possibility that the bucket 10 enters the target surface St(n) when operation of the arm 9 is carried out is determined to exist in the target surface St(n) that exist in the travelling direction of the bucket 10. Due to this, in the case in which plural target surfaces are set, it is possible to prevent the occurrence of shock attributed to a transition of the state between the deceleration control state and the deactivation state of the deceleration control when the closest target surface St(0) is switched to the adjacent target surface St(1) or St(−1) due to operation of the arm 9. This allows the arm 9 to smoothly make action. Therefore, the operability is high and improvement in the work efficiency can be intended.
In the example illustrated in
Furthermore, in the example illustrated in
In the example illustrated in
In the example illustrated in
In the example illustrated in
As above, according to the present embodiment, in work in the state in which the ground leveling control mode is set, opportunities for execution of the deceleration control of the arm 9 can be reduced compared with the case in which the deceleration control of the arm 9 is carried out across the board when the bucket-to-target surface distance H1(n) has become shorter than the predetermined distance Ya. Due to this, for example, in the case in which, in excavation and ground leveling work, work of returning the bucket 10 to the work start point of them, work of excavating the upper side of the target surface St, work of shaking down earth from the bucket 10, and so forth are carried out in the deceleration region (H1(n)<Ya), limitation on action of the arm 9 is suppressed and it is possible to cause the work device 1A to carry out operation according to the intension of the operator. That is, limitation about the respective actions of arm crowding and arm dumping is alleviated even under the condition in which the action velocity of the arm 9 is limited by the MC originally (that is, when H1(n)<Ya). Therefore, according to the present embodiment, the work efficiency of excavation and ground leveling work by arm pulling and ground leveling work by arm pushing can be improved.
According to the above-described embodiment, the following operation and effects are provided.
(1) The hydraulic excavator (work machine) 101 according to the present embodiment includes the controller 40 that sets the target surface St, and calculates the bucket-to-target surface distance H1 that is the distance from the bucket (work equipment) 10 to the target surface St on the basis of signals from the GNSS antennas (position sensor) 14 and the angle sensors (posture sensor) 30 to 33, and controls the boom 8 and carries out the deceleration control to decelerate the arm 9 to keep the bucket 10 from excavating the ground beyond the target surface St when operation of the arm 9 is carried out by the operation device 45 and the bucket-to-target surface distance H1 has become shorter than the threshold (predetermined distance) Ya. Furthermore, the controller 40 determines whether or not there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out, on the basis of the target surface St that is set and the signals from the GNSS antennas 14 and the angle sensors 30 to 33, and does not carry out the deceleration control even when the bucket-to-target surface distance H1 is shorter than the predetermined distance Ya in the case in which it is determined that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out.
Therefore, according to the present embodiment, when it is determined that there is a possibility that the bucket 10 enters the target surface St, the deceleration control of arm crowding (arm pulling) and the deceleration control of arm dumping (arm pushing) are carried out. Thus, the ground leveling work can be surely carried out by the machine control. On the other hand, when it is determined that there is no possibility that the bucket 10 enters the target surface St, the deceleration control of arm crowding (arm pulling) and the deceleration control of arm dumping (arm pushing) are not carried out. That is, according to the present embodiment, opportunities for execution of the deceleration control of the arm 9 can be reduced and therefore the efficiency of work of excavation, ground leveling, and so forth by the hydraulic excavator 101 can be improved.
(2) When combined operation of lowering operation of the boom 8 and operation of the arm 9 is being carried out, even in the case in which the posture of the work device 1A is not the entry posture, the deceleration control of the arm 9 by the normal MC is carried out when the bucket-to-target surface distance H1(n) is shorter than the predetermined distance Ya (for example, Y in S120 in
The step S140 and the step S150 illustrated in
A hydraulic excavator 201 according to a second embodiment will be described with reference to
The hydraulic excavator 201 according to the second embodiment has a configuration similar to the first embodiment. Here, when, as illustrated in
In the case of carrying out such work, with the configuration of the above-described first embodiment, there is a fear that sudden action of the arm 9 occurs when the angle φ exceeds 90°. In the first embodiment, for example, as illustrated in
Similarly, as illustrated in
Thus, in the present second embodiment, when it is determined that the posture of the work device 1A is not the entry posture, transition control to change the velocity of the arm 9 according to change in the angle φ formed by the line segment Lpb and the target surface St is carried out. Whether or not execution of the transition control is possible is decided according to the setting state of a transition control execution flag Fct(n) or Fdt(n).
Steps S305, S320, S330, S345, S350, S355, and S360 illustrated in
Loop processing (S310, S390) illustrated in
When it is determined in the step S350 that the angle φ(n) is equal to or larger than 90°, progress to a step S380 is made. Furthermore, when it is determined in the step S360 that the distance H1(n) is shorter than the threshold Ya1, progress to a step S370 is made. When it is determined that the distance H1(n) is equal to or longer than the threshold Ya1, progress to a step S380 is made.
In the step S370, the controller 40 sets the transition control execution flag Fct(n) to 0 (Fct(n)=0). Then, progress to the step S390 is made to end the series of processing regarding the relevant target surface St(n). In the step S380, the controller 40 sets the transition control execution flag Fct(n) to 1 (Fct(n)=1). Then, progress to the step S390 is made to end the series of processing regarding the relevant target surface St(n).
That is, the controller 40 sets the transition control execution flag Fct(n) to 1 (Fct(n)=1) when it is determined that there is no possibility that the bucket 10 enters the target surface St(n) due to arm crowding operation through the determination that the angle φ(n) is equal to or larger than 90°.
When the loop processing is completed, progress to the step S395 is made and mode setting processing is executed. In the step S395, the controller 40 determines whether or not all of the transition control execution flags Fct(n), (n=m to 0) are set to Fct(n)=1, and determines whether or not execution of the transition control is possible on the basis of the determination result. When it is determined that all of the transition control execution flags Fct(n) are not set to Fct(n)=1, i.e. when even one of the transition control execution flags Fct(n), (n=m to 0) is determined to be set to Fct(n)=0, the controller 40 sets a mode in which the transition control is not carried out. When it is determined that all of the transition control execution flags Fct(n), (n=m to 0) are set to Fct(n)=1, the controller 40 sets a mode in which the transition control is carried out. When the mode setting processing (S395) ends, the processing illustrated in the flowchart of
Steps S405, S420, S430, S445, S450, S455, and S460 illustrated in
Loop processing (S410, S490) illustrated in
When it is determined in the step S450 that the angle φ(n) is smaller than 90°, progress to a step S480 is made. Furthermore, when it is determined in the step S460 that the distance H1(n) is shorter than the threshold Ya2, progress to a step S470 is made. When it is determined that the distance H1(n) is equal to or longer than the threshold Ya2, progress to a step S480 is made.
In the step S470, the controller 40 sets the transition control execution flag Fdt(n) to 0 (Fdt(n)=0). Then, progress to the step S490 is made to end the series of processing regarding the relevant target surface St(n). In the step S480, the controller 40 sets the transition control execution flag Fdt(n) to 1 (Fdt(n)=1). Then, progress to the step S490 is made to end the series of processing regarding the relevant target surface St(n).
That is, the controller 40 sets the transition control execution flag Fdt(n) to 1 (Fdt(n)=1) when it is determined that there is no possibility that the bucket 10 enters the target surface St(n) due to arm dumping operation through the determination that the angle φ(n) is smaller than 90°.
When the loop processing is completed, progress to the step S495 is made and mode setting processing is executed. In the step S495, the controller 40 determines whether or not all of the transition control execution flags Fdt(n), (n=0 to q) are set to Fdt(n)=1, and determines whether or not execution of the transition control is possible on the basis of the determination result. When it is determined that all of the transition control execution flags Fdt(n) are not set to Fdt(n)=1, i.e. when even one of the transition control execution flags Fdt(n), (n=0 to q) is determined to be set to Fdt(n)=0, the controller 40 sets a mode in which the transition control is not carried out. When it is determined that all of the transition control execution flags Fdt(n), (n=0 to q) are set to Fdt(n)=1, the controller 40 sets a mode in which the transition control is carried out. When the mode setting processing (S495) ends, the processing illustrated in the flowchart of
The transition control carried out by an intervention deactivation calculating section 243f according to the second embodiment will be described in detail with reference to
As illustrated in
The intervention deactivation calculating section 243f adds the multiplication value of the arm crowding target pilot pressure Pct and (1−αp) to the multiplication value of the maximum pressure Pmax and αp (L107) and outputs the arm crowding transition pressure that is the calculation result thereof as the target pilot pressure (L108).
As illustrated in
The intervention deactivation calculating section 243f adds the multiplication value of the arm dumping target pilot pressure Pdt and (1−βp) to the multiplication value of the maximum pressure Pmax and βp (L207) and outputs the arm dumping transition pressure that is the calculation result thereof as the target pilot pressure (L208).
According to such a second embodiment, when it is determined that the posture of the work device 1A is not the entry posture due to action of the arm 9 and crossing 90° by the angle φ and the deceleration control is deactivated, the velocity of the arm 9 can be changed by gradually increasing the target pilot pressure according to change in the angle φ. That is, it is possible to prevent the velocity of the arm 9 from suddenly changing when a transition is made from the state in which the deceleration control is carried out to the state in which the deceleration control is not carried out due to change in the angle φ.
The following modification examples are also within the range of the present invention and it is also possible to combine a configuration shown in the modification example and a configuration explained in the above-described embodiment and to combine configurations to be explained in the following different modification examples with each other.
In the above-described embodiment, explanation has been made about the example in which the magnitude relation between the pin-to-target surface distance H2(n) and the pin-to-bucket distance Dpb is compared with each other as it is and the deceleration control of the arm 9 is not carried out when the distance H2(n) is equal to or longer than the distance Dpb (see the step S140 in
In the above-described embodiment, explanation has been made about the example in which the controller 40 determines that there is no possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out in the case in which the controller 40 calculates the pin-to-bucket distance Dpb and calculates the pin-to-target surface distance H2 and determines whether or not the posture of the work device 1A is the entry posture on the basis of the pin-to-bucket distance Dpb and the pin-to-target surface distance H2 and it is determined that the posture of the work device 1A is not the entry posture or in the case in which the controller 40 calculates the angle φ and determines whether or not the posture of the work device 1A is the entry posture on the basis of the angle φ and it is determined that the posture of the work device 1A is not the entry posture. Furthermore, in the above-described embodiment, explanation has been made about the example in which the controller 40 determines that there is a possibility that the bucket 10 enters the target surface St when operation of the arm 9 is carried out in the case in which the controller 40 determines whether or not the posture of the work device 1A is the entry posture on the basis of the pin-to-bucket distance Dpb and the pin-to-target surface distance H2 and it is determined that the posture of the work device 1A is the entry posture and the controller 40 determines whether or not the posture of the work device 1A is the entry posture on the basis of the angle φ and it is determined that the posture of the work device 1A is the entry posture. However, the present invention is not limited thereto. For example, the steps S145 and S150 in
In the above-described embodiment, explanation has been made about the example in which, when combined operation of lowering operation of the boom 8 and operation of the arm 9 by the operator is being carried out, the deceleration control of the arm 9 is carried out even when the posture of the work device 1A is not the entry posture (for example, when the distance H2 is equal to or longer than the distance Dpb). However, the present invention is not limited thereto. For example, in the step S130 in
In the hydraulic excavator 101, a solenoid proportional valve and a shuttle valve with a configuration similar to the solenoid proportional valve 54a and the shuttle valve 82a disposed in the hydraulic circuit on the boom raising side, illustrated in
In the present modification example 3, in the step S130 in
Although the embodiments of the present invention have been described above, the above-described embodiments merely show part of application examples of the present invention and do not intend to limit the technical range of the present invention to specific configurations of the above-described embodiments.
Number | Date | Country | Kind |
---|---|---|---|
2019-180334 | Sep 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2020/034010 | 9/8/2020 | WO | 00 |