Estimation system and estimation method

Abstract

An estimation system according to one embodiment is for a construction machine including a plurality of movable members and a plurality of hydraulic actuators, and includes a processing circuit (71). The processing circuit (71) calculates an excavation reaction force that is an external force acting on the bucket during excavation and a payload that is the weight of sediment in the bucket during excavation on the basis of the actual attitude angle of the plurality of movable members and the actual torque with respect to the plurality of movable members by the plurality of hydraulic actuators, and outputs the calculated excavation reaction force and payload as an excavation reaction force estimation value and a payload estimation value. The processing circuit (71) uses the payload calculated immediately before as a payload input value when calculating the excavation reaction force, and uses the excavation reaction force calculated immediately before as an excavation reaction force input value when calculating the payload.

Description

Estimation system and estimation method

[0001] The present disclosure relates to an estimation system and an estimation method for a construction machine.

[0002] Some construction machines include a bucket for excavating earth and sand, such as hydraulic excavators and wheel loaders. For example, Patent Document 1 describes a method for calculating an excavation reaction force, which is an external force acting on a bucket during excavation, based on the displacements and pressures of a boom cylinder, an arm cylinder, and a bucket cylinder in a hydraulic excavator that includes a boom, an arm, and a bucket.

[0003] JP 2015-158049 A

[0004] In construction machinery, there is a demand to estimate not only the excavation reaction force but also the payload, which is the weight of the soil in the bucket.

[0005] Therefore, an object of the present disclosure is to provide an estimation system and an estimation method that can estimate both the excavation reaction force and the payload.

[0006] From one aspect, the present disclosure provides an estimation system including a processing circuit for a construction machine including a plurality of movable members including a bucket for excavating earth and sand, and a plurality of hydraulic actuators for rotating each of the plurality of movable members, wherein the processing circuit is configured to calculate an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on the actual attitude angles of the plurality of movable members and the actual torques applied to the plurality of movable members by the plurality of hydraulic actuators, and output the calculated excavation reaction force and payload as an excavation reaction force estimated value and a payload estimated value, and when calculating the excavation reaction force, the most recently calculated payload is used as a payload input value, and when calculating the payload, the most recently calculated excavation reaction force is used as the excavation reaction force input value.

[0007] From another aspect, the present disclosure provides an estimation method for a construction machine that includes a plurality of movable members including a bucket that excavates earth and sand, and a plurality of hydraulic actuators that rotate the plurality of movable members, the estimation method calculating an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on actual attitude angles of the plurality of movable members and actual torques applied to the plurality of movable members by the plurality of hydraulic actuators, and outputting the calculated excavation reaction force and payload as an excavation reaction force estimated value and a payload estimated value, and when calculating the excavation reaction force, using the payload calculated immediately before as a payload input value, and when calculating the payload, using the excavation reaction force calculated immediately before as the excavation reaction force input value.

[0008] According to the present disclosure, an estimation system and an estimation method are provided that are capable of estimating both the excavation reaction force and the payload.

[0009] It is a model diagram of a hydraulic excavator, which is an example of a construction machine, modeled with four links. It is a diagram showing a hydraulic circuit incorporated in the construction machine. It is a schematic configuration diagram of an estimation system for the construction machine. It is a block diagram of a processing circuit of a controller.

[0010] Fig. 1 shows a construction machine 1, and Fig. 3 shows an estimation system 4 for the construction machine 1. In this embodiment, the construction machine 1 is a hydraulic excavator 10. However, the estimation system 4 may also be used in construction machines 1 other than the hydraulic excavator 10, such as wheel loaders, as long as the construction machine 1 includes a bucket 16 for excavating earth and sand.

[0011] The construction machine 1 includes a running body 11 and a plurality of movable members 12 that constitute an articulated body rotatably supported on the running body 11. In other words, the movable members 12 are rotatably connected to each other, and the movable member 12 closest to the running body 11 is rotatably connected to the running body 11. In this embodiment, the running body 11 includes a pair of crawlers.

[0012] The bucket 16 is located at the tip of the articulated body. That is, the side of the traveling body 11 opposite to the bucket 16 is the base end side, and the bucket 16 side is the tip end side.

[0013] 2, the construction machine 1 further includes travel motors 31, 32 that respectively drive the pair of crawlers, and a plurality of hydraulic actuators 33 that respectively rotate the movable member 12. The travel motors 31, 32 and the hydraulic actuators 33, together with the hydraulic pump 21, constitute the hydraulic circuit 2.

[0014] More specifically, the hydraulic pump 21 is connected to a valve unit 22 including a plurality of control valves, and the travel motors 31, 32 and the hydraulic actuator 33 are connected to this valve unit 22. In other words, hydraulic oil is supplied to each of the travel motors 31, 32 and the hydraulic actuator 33 from the hydraulic pump 21 via the corresponding control valve.

[0015] In this embodiment, the construction machine 1 is a hydraulic excavator 10, and therefore the movable member 12 includes a rotating body 13, a boom 14, an arm 15, and the above-mentioned bucket 16, as shown in FIG. 1, and the hydraulic actuator 33 includes a swing motor 34, a boom cylinder 35, an arm cylinder 36, and a bucket cylinder 37, as shown in FIG. 2.

[0016] The swing motor 34 rotates the rotating unit 13 relative to the running unit 11 around a rotation axis Jsw that extends at the center of the running unit 11 in a direction perpendicular to the front-to-rear and width directions of the running unit 11, and the boom cylinder 35 rotates the boom 14 relative to the rotating unit 13 around a rotation axis Jbm that extends at the base end of the boom 14 in the width direction of the rotating unit 13. The arm cylinder 36 rotates the arm 15 relative to the boom 14 around a rotation axis Jam that extends at the tip of the boom 14 in the width direction of the rotating unit 13, and the bucket cylinder 37 rotates the bucket 16 relative to the arm 15 around a rotation axis Jbt that extends at the tip of the arm 15 in the width direction of the rotating unit 13.

[0017] As shown in FIG. 3, the estimation system 4 for the construction machine 1 includes a controller 7, and a plurality of attitude angle sensors 5 and pressure sensors 6 connected to the controller.

[0018] With respect to the controller 7, the functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0019] In this embodiment, the attitude angle sensor 5 includes a vehicle body attitude angle sensor 51, a swing attitude angle sensor 52, a boom attitude angle sensor 53, an arm attitude angle sensor 54, and a bucket attitude angle sensor 55. The vehicle body attitude angle sensor 51 detects the vehicle body attitude angle, which is the inclination angle of the traveling body 11 with respect to the horizontal plane. The swing attitude angle sensor 52 detects the swing attitude angle, which is the angle of the fore-and-aft direction of the rotating body 13 with respect to the fore-and-aft direction of the traveling body 11 on a plane perpendicular to the rotation axis Jsw. The boom attitude angle sensor 53 detects the boom attitude angle, which is the inclination angle of the boom 14 with respect to the horizontal plane. The arm attitude angle sensor 54 detects the arm attitude angle, which is the inclination angle of the arm 15 with respect to the horizontal plane. The bucket attitude angle sensor 55 detects the bucket attitude angle, which is the inclination angle of the bucket 16 with respect to the horizontal plane.

[0020] In this embodiment, the pressure sensors 6 include a swing pressure sensor 61, a boom pressure sensor 62, an arm pressure sensor 63, and a bucket pressure sensor 64. The swing pressure sensor 61 detects the differential pressure between the inflow pressure and outflow pressure of the swing motor 34 as the load pressure. The boom pressure sensor 62 detects the load pressure, which is the head side pressure or rod side pressure of the boom cylinder 35. The arm pressure sensor 63 detects the load pressure, which is the head side pressure or rod side pressure of the arm cylinder 36. The bucket pressure sensor 64 detects the load pressure, which is the head side pressure or rod side pressure of the bucket cylinder 37.

[0021] As shown in FIG. 4 , the controller 7 includes a processing circuit 71. The processing circuit 71 calculates an excavation reaction force F, which is an external force acting on the tip of the bucket 16, and a payload m, which is the weight of soil and sand in the bucket 16, based on the actual attitude angle θo detected by the attitude angle sensor 5 and the actual torque τ applied to the movable member 12 by the hydraulic actuator 33, which is calculated from the load pressure detected by the pressure sensor 6, and outputs the calculated excavation reaction force F and payload m as an excavation reaction force estimated value Fe and a payload estimated value me. The output destination is, for example, a display device. The actual attitude angle θo and actual torque τ are vectors defined by multiple components. For example, the actual torque τ is expressed by the following equation 1. τsw: actual torque applied to the swing body 13 by the swing motor 34 τbm: actual torque applied to the boom 14 by the boom cylinder 35 τam: actual torque applied to the arm 15 by the arm cylinder 36 τbt: actual torque applied to the bucket 16 by the bucket cylinder 37

[0022] More specifically, the processing circuit 71 uses a model as shown in Fig. 1. The model includes a swing link 1a representing the swing unit 13 as a straight line between the swing axis Jsw and the swing axis Jbm, a boom link 1b representing the boom 14 as a straight line between the swing axis Jbm and the swing axis Jam, an arm link 1c representing the arm 15 as a straight line between the swing axis Jam and the swing axis Jbt, and a bucket link 1d representing the bucket 16 as a straight line between the swing axis Jbt and the tip of the bucket 16. The processing circuit 71 calculates the actual relative angle θ of the movable member 12 with respect to the base-end member from the actual attitude angle θo detected by the attitude angle sensor 5. The actual relative angle θ is expressed by the following equation 2. θsw: actual relative angle of the swing unit 13 with respect to the running unit 11 (in the model, this is the angle between the longitudinal direction of the running unit 11 and the swing link 1a when viewed from the extension direction of the rotation axis Jsw) θbm: actual relative angle of the boom 14 with respect to the swing unit 13 (in the model, this is the angle between the swing link 1a and the boom link 1b) θam: actual relative angle of the arm 15 with respect to the boom 14 (in the model, this is the angle between the boom link 1b and the arm link 1c) θbm: actual relative angle of the bucket 16 with respect to the arm 15 (in the model, this is the angle between the arm link 1c and the bucket link 1d)

[0023] The processing circuit 71 repeatedly performs calculations according to the flow shown in Fig. 4 and calculates the excavation reaction force F and the payload m based on data sampled at predetermined time intervals. Note that "sampled data" refers to data acquired, extracted, or selected as input data for calculation.

[0024] When calculating the excavation reaction force F, the processing circuit 71 first calculates an estimated torque τe of the movable member 12 by inverse dynamics calculation using the following equation 3, as shown in the flow chart on the left side of FIG.

[0025] In the above equation, M(θ) is a matrix containing the inertia tensor around each rotation axis as its component, h(θ, dθ / dt) is a matrix whose components are the centrifugal force and Coriolis force around each rotation axis, and G(θ) is a matrix whose components are the gravity of each movable member 12. Since the calculation methods for these are known, their explanation will be omitted. Note that the bucket gravity in G(θ) is the sum of the gravity of the bucket 16 itself and the payload m. Furthermore, the inertia tensor M(θ) also includes the soil tensor calculated from the payload m, and the influence of the excavation reaction force F is added to the torque τ as an external force.

[0026] In the above inverse dynamics calculation, the processing circuit 71 uses the actual relative angle θ and the payload input value mi, and sets the excavation reaction force input value Fi to zero. The payload input value mi is the payload m calculated immediately before, that is, the previous time. In the first calculation, the previously calculated payload m does not exist, so the processing circuit 71 sets the payload input value mi to zero in the first calculation.

[0027] Regarding the use of the payload input value mi, when an upward vertical direction is positive and a downward vertical direction is negative, the processing circuit 71 sets the most recently calculated payload m as the payload input value mi if the vertical component Fy of the excavation reaction force F calculated immediately before is negative or zero, and sets the payload input value mi to zero if the vertical component Fy of the excavation reaction force F calculated immediately before is positive. Note that in the first calculation, the excavation reaction force F calculated immediately before does not exist, but this does not pose a problem because the payload input value mi is set to zero in the first calculation as described above.

[0028] After calculating the estimated torque τe, the processing circuit 71 calculates the excavation reaction force F based on the deviation Δτ between the actual torque τ and the estimated torque τe, where Δτ=τ−τe. The estimated torque τe is expressed by the following equation 4.

[0029] Specifically, as shown in Figure 1, the processing circuit 71 first calculates the angle θamh between the horizontal plane and the line Lamh connecting the rotation axis Jam, which is the rotation center of the arm 15, and the tip of the bucket 16, and the angle θbmh between the horizontal plane and the line Lbmh connecting the rotation axis Jbm, which is the rotation center of the boom 14, and the tip of the bucket 16.

[0030] Thereafter, the processing circuit 71 calculates the horizontal component Fx and vertical component Fy of the excavation reaction force F, which are parallel to the front-to-rear direction of the revolving body 13, using the following equations 5 and 6.

[0031] In addition, for Δτam in equation 5, Δτam = τam - τame, and lamh is the length of line Lamh. Also, for Δτbm in equation 6, Δτbm = τbm - τbme, and lbmh is the length of line Lbmh.

[0032] Furthermore, the processing circuit 71 calculates the horizontal component Fz of the excavation reaction force F, which is parallel to the width direction of the rotating body 13, using the following equation 7. Note that Δτsw in equation 7 is Δτsw = τsw - τswe, and lswh is the horizontal distance from the rotation axis Jsw, which is the rotation center of the rotating body 13, to the tip of the bucket 16.

[0033] Thereafter, the processing circuit 71 outputs the excavation reaction force F calculated as described above as an excavation reaction force estimated value Fe.

[0034] When calculating the payload m, the processing circuit 71 first calculates the estimated torque τe of the movable member 12 by inverse dynamics calculation using the above-mentioned equation 3, as shown in the flow on the right side of Fig. 4. At this time, the processing circuit 71 uses the actual relative angle θ and the excavation reaction force input value Fi, and sets the payload input value mi to zero. The excavation reaction force input value Fi is the excavation reaction force F calculated immediately before, that is, calculated in the same time.

[0035] After calculating the estimated torque τe, the processing circuit 71 calculates the payload m based on the deviation Δτ between the actual torque τ and the estimated torque τe. Specifically, the processing circuit 71 calculates the payload m using the following equation 8.

[0036] In Equation 8, lbm is the length of the boom link 1b. Also, α and β in Equation 8 are terms in the Newton-Euler equation. Note that the method for calculating α and β is known, so the explanation will be omitted.

[0037] Thereafter, the processing circuit 71 outputs the payload m calculated as described above as a payload estimate me.

[0038] Here, the excavation reaction force input value Fi and payload input value mi input into Equation 3 will be described in relation to the case where the excavation reaction force F and payload m are calculated based on data sampled at predetermined time intervals.

[0039] When calculating the excavation reaction force F(t=n) at a predetermined time t=n, the payload input value mi input to equation 3 in the flow on the left side of Fig. 4 is the payload m(t=n-1) at the time t=n-1 calculated immediately before, that is, the previous time, in the flow on the right side of Fig. 4, as described above. Furthermore, when calculating the excavation reaction force F(t=1) at time t=1, the payload input value mi input to equation 3 is payload m(t=0), but in this embodiment, as described above, payload m(t=0)=0.

[0040] When calculating the payload m(t=n) at a predetermined time t=n, the excavation reaction force input value Fi input to equation 3 in the flow on the right side of Fig. 4 is, as described above, the excavation reaction force F(t=n) at the immediately preceding time, i.e., the time t=n calculated in the flow on the left side of Fig. 4. Furthermore, when calculating the payload m(t=1) at time t=1, the excavation reaction force input value Fi input to equation 3 is the excavation reaction force F(t=1).

[0041] The data sampling period may be any time interval, such as 0.01 seconds, 0.1 seconds, or 1 second.

[0042] As described above, the estimation system 4 of this embodiment can estimate both the excavation reaction force F and the payload m using the dual filter structure shown in Fig. 4. Moreover, by using the excavation reaction force F and payload m calculated immediately before as the excavation reaction force input value Fi and the payload input value mi that form the loop of the dual filter structure, the excavation reaction force F and the payload m can be estimated with high accuracy.

[0043] Furthermore, the dual filter structure shown in FIG. 4 makes it possible to estimate the excavation reaction force F and the payload m without using a force sensor such as a load cell.

[0044] Furthermore, in this embodiment, when calculating the excavation reaction force F, if the vertical component Fy of the excavation reaction force F calculated immediately before is positive, the payload input value mi is set to zero, thereby preventing divergence of the estimation calculation. This enables stable estimation of the excavation reaction force F and the payload m.

[0045] <Modifications> The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present disclosure.

[0046] For example, the traveling body 11 may include a plurality of wheels instead of a pair of crawlers. In this case, the hydraulic circuit 2 may not include the traveling motors 31 and 32, and the wheels may be driven by an engine or an electric motor.

[0047] Furthermore, when calculating the payload m(t=n) at a predetermined time t=n, the excavation reaction force input value Fi input to equation 3 in the flow on the right side of Fig. 4 may be the excavation reaction force F(t=n-1) at time t=n-1. In that case, when calculating the payload m(t=1) at time t=1, the excavation reaction force input value Fi input to equation 3 becomes the excavation reaction force F(t=0), and at this time the excavation reaction force F(t=0)=0 may be set.

[0048] However, compared to the above-described embodiment, the modified example uses the specified value of the excavation reaction force F(t=0)=0 instead of the excavation reaction force F(t=1) calculated in the flow on the left side of Fig. 4, and therefore the estimation accuracy of the payload m(t=1) is inferior to that of the embodiment. The difference in estimation accuracy of the payload m(t=1) also affects the excavation reaction force F(t=n) and payload m(t=n) calculated subsequently, and therefore the above-described embodiment can estimate the excavation reaction force F and payload m with higher accuracy than the modified example.

[0049] <Summary> In a first aspect, the present disclosure provides, from one aspect, an estimation system including a processing circuit for a construction machine including a plurality of movable members including a bucket for excavating earth and sand, and a plurality of hydraulic actuators for rotating each of the plurality of movable members, wherein the processing circuit calculates an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on actual attitude angles of the plurality of movable members and actual torques applied to the plurality of movable members by the plurality of hydraulic actuators, and outputs the calculated excavation reaction force and payload as an excavation reaction force estimated value and a payload estimated value, and when calculating the excavation reaction force, the most recently calculated payload is used as a payload input value, and when calculating the payload, the most recently calculated excavation reaction force is used as the excavation reaction force input value.

[0050] According to the above configuration, both the excavation reaction force and the payload can be estimated using the dual filter structure. Moreover, by using the most recently calculated excavation reaction force and payload as the excavation reaction force input value and the payload input value that form the loop of the dual filter structure, the excavation reaction force and the payload can be estimated with high accuracy.

[0051] As a second aspect, in the first aspect, when calculating the excavation reaction force, the processing circuit may set the most recently calculated payload as the payload input value if the vertical component of the most recently calculated excavation reaction force is negative, where a vertically upward direction is positive and a vertically downward direction is negative, and set the payload input value to zero if the vertical component of the most recently calculated excavation reaction force is positive. This configuration can prevent divergence in the estimation calculation, thereby enabling stable estimation of the excavation reaction force and payload.

[0052] As a third aspect, in the first or second aspect, the side opposite the bucket may be the base end side, and the processing circuit, when calculating the excavation reaction force, may use actual relative angles with respect to a base end member calculated from actual attitude angles of the plurality of movable members and the payload input value, and calculate an estimated torque of the plurality of movable members by inverse dynamics calculation with the excavation reaction force input value set to zero, and calculate the excavation reaction force based on a deviation between the actual torque and the estimated torque; and when calculating the payload, may use actual relative angles with respect to a base end member calculated from actual attitude angles of the plurality of movable members and the excavation reaction force input value, and calculate an estimated torque of the plurality of movable members by inverse dynamics calculation with the payload input value set to zero, and calculate the payload based on the deviation between the actual torque and the estimated torque. With this configuration, the excavation reaction force and payload can be estimated without using a force sensor such as a load cell.

[0053] As a fourth aspect, in any of the first to third aspects, for example, the construction machine may be a hydraulic excavator, and the plurality of movable members may include a rotating body, a boom, and an arm in addition to the bucket.

[0054] In a fifth aspect, from another aspect, the present disclosure provides an estimation method for a construction machine that includes a plurality of movable members including a bucket that excavates earth and sand, and a plurality of hydraulic actuators that rotate the plurality of movable members, the estimation method calculating an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on actual attitude angles of the plurality of movable members and actual torques applied to the plurality of movable members by the plurality of hydraulic actuators, and outputting the calculated excavation reaction force and payload as an excavation reaction force estimated value and a payload estimated value, and when calculating the excavation reaction force, using the payload calculated immediately before as a payload input value, and when calculating the payload, using the excavation reaction force calculated immediately before as the excavation reaction force input value.

[0055] According to the above configuration, both the excavation reaction force and the payload can be estimated using the dual filter structure. Moreover, by using the most recently calculated excavation reaction force and payload as the excavation reaction force input value and the payload input value that form the loop of the dual filter structure, the excavation reaction force and the payload can be estimated with high accuracy.

[0056] As a sixth aspect, in the fifth aspect, when calculating the excavation reaction force, if a vertical component of the excavation reaction force calculated immediately before is negative, the payload calculated immediately before may be used as the payload input value, and if the vertical component of the excavation reaction force calculated immediately before is positive, the payload input value may be set to zero. This configuration can prevent divergence in the estimation calculation, thereby enabling stable estimation of the excavation reaction force and the payload.

[0057] As a seventh aspect, in the fifth or sixth aspect, the side opposite the bucket may be the base end side, and when calculating the excavation reaction force, actual relative angles with respect to a base end member calculated from actual attitude angles of the plurality of movable members and the payload input value may be used, and an estimated torque of the plurality of movable members may be calculated by inverse dynamics calculation with the excavation reaction force input value set to zero, and the excavation reaction force may be calculated based on a deviation between the actual torque and the estimated torque, and when calculating the payload, actual relative angles with respect to a base end member calculated from actual attitude angles of the plurality of movable members and the excavation reaction force input value may be used, and an estimated torque of the plurality of movable members may be calculated by inverse dynamics calculation with the payload input value set to zero, and the payload may be calculated based on the deviation between the actual torque and the estimated torque. With this configuration, the excavation reaction force and the payload can be estimated without using a force sensor such as a load cell.

[0058] As an eighth aspect, in any of the fifth to seventh aspects, for example, the construction machine may be a hydraulic excavator, and the plurality of movable members may include a rotating body, a boom, and an arm in addition to the bucket.

Claims

1. An estimation system having a processing circuit for a construction machine that includes a plurality of movable members including a bucket for excavating earth and a plurality of hydraulic actuators for rotating each of the plurality of movable members, wherein the processing circuit is configured to: calculate an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on the actual attitude angles of the plurality of movable members and the actual torques applied to the plurality of movable members by the plurality of hydraulic actuators; output the calculated excavation reaction force and payload as an excavation reaction force estimate and a payload estimate; when calculating the excavation reaction force, the most recently calculated payload is used as a payload input value; and when calculating the payload, the most recently calculated excavation reaction force is used as the excavation reaction force input value.

2. The estimation system of claim 1, wherein when calculating the excavation reaction force, the processing circuit, assuming that an upward vertical direction is positive and a downward vertical direction is negative, sets the payload calculated immediately before as the payload input value if the vertical component of the excavation reaction force calculated immediately before is negative, and sets the payload input value to zero if the vertical component of the excavation reaction force calculated immediately before is positive.

3. The estimation system according to claim 1 or 2, wherein the side opposite the bucket is the base side, and wherein the processing circuit, when calculating the excavation reaction force, uses actual relative angles with respect to the base side member calculated from the actual attitude angles of the plurality of movable members and the payload input value, and calculates estimated torques of the plurality of movable members by inverse dynamics calculation with the excavation reaction force input value set to zero, and calculates the excavation reaction force based on the deviation between the actual torque and the estimated torque; and when calculating the payload, uses actual relative angles with respect to the base side member calculated from the actual attitude angles of the plurality of movable members and the excavation reaction force input value, and calculates estimated torques of the plurality of movable members by inverse dynamics calculation with the payload input value set to zero, and calculates the payload based on the deviation between the actual torque and the estimated torque.

4. The estimation system according to claim 1 or 2, wherein the construction machine is a hydraulic excavator, and the plurality of movable members include a rotating body, a boom, and an arm in addition to the bucket.

5. An estimation method for a construction machine including a plurality of movable members including a bucket for excavating earth and sand, and a plurality of hydraulic actuators for rotating the plurality of movable members, the method calculating an excavation reaction force, which is an external force acting on the bucket during excavation, and a payload, which is the weight of earth and sand in the bucket, based on the actual attitude angles of the plurality of movable members and the actual torques applied to the plurality of movable members by the plurality of hydraulic actuators, and outputting the calculated excavation reaction force and payload as an excavation reaction force estimate and a payload estimate, the method using the payload calculated immediately before as a payload input value when calculating the excavation reaction force, and the method using the excavation reaction force calculated immediately before as an excavation reaction force input value when calculating the payload.

6. An estimation method according to claim 5, wherein, when calculating the excavation reaction force, when a vertical component of the excavation reaction force calculated immediately before is negative, the payload calculated immediately before is used as the payload input value, and when the vertical component of the excavation reaction force calculated immediately before is positive, the payload input value is set to zero.

7. The estimation method according to claim 5 or 6, wherein the side opposite the bucket is the base end side, and when calculating the excavation reaction force, actual relative angles with respect to the base end member calculated from the actual attitude angles of the plurality of movable members and the payload input value are used, and an estimated torque of the plurality of movable members is calculated by inverse dynamics calculation with the excavation reaction force input value set to zero, and the excavation reaction force is calculated based on the deviation between the actual torque and the estimated torque, and when calculating the payload, actual relative angles with respect to the base end member calculated from the actual attitude angles of the plurality of movable members and the excavation reaction force input value are used, and an estimated torque of the plurality of movable members is calculated by inverse dynamics calculation with the payload input value set to zero, and the payload is calculated based on the deviation between the actual torque and the estimated torque.

8. The estimation method according to claim 5 or 6, wherein the construction machine is a hydraulic excavator, and the plurality of movable members include a rotating body, a boom, and an arm in addition to the bucket.

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