JP6964054B2 - Construction machinery - Google Patents

Description

The present disclosure relates to a construction machine that is swiveled by an electric swivel motor.

For example, as shown in Patent Documents 1 and 2, a hybrid type electric swivel construction machine has been developed in which an upper swivel body is driven by an electric swivel motor and a working machine or a traveling body is driven by a hydraulic actuator. In addition to the cabin and engine, working machines such as booms and arms are mounted on the upper swing body. The work machine has a large weight, and the moment of inertia of the upper swing body differs between the state in which the boom or arm is extended and the state in which the boom or arm is contracted. On slopes, gravity generates torque around the rotation axis of the upper swing body in the direction of going down the slope. It is known that this torque adversely affects the turning operation.

Patent Document 1 issues a control command for an electric swivel motor when the operating lever is in a neutral position and the target speed of the upper swivel body falls below a predetermined threshold in order to reliably maintain the stationary state of the upper swivel body on a slope. A technique for switching control from speed control to position control is disclosed.

Patent Document 2 is a swivel drive control device for a construction machine that is swiveled by an electric motor. A control device for reducing the turning motion of the above is disclosed.

Japanese Unexamined Patent Publication No. 2012-122327 Japanese Unexamined Patent Publication No. 2010-138586

However, Patent Documents 1 and 2 do not consider the torque component generated by gravity and the change of this torque component due to the expansion and contraction of the boom or the arm, so that even if the amount of operation is the same, the direction of climbing a slope The behavior differs between when turning and when turning down a slope, and the operability of turning is impaired.

In Patent Document 2, since the control for reducing the turning motion in the opposite direction does not work until the turning motion in the direction opposite to the turning operation direction is detected, an unintended drop of the upper swing body always occurs.

In both Patent Documents 1 and 2, feedback control is performed so that the rotation speed is detected and the deviation from the target rotation speed becomes small, so that the adverse effect of the torque component generated by gravity on a sloping ground actually affects the rotation speed. Since the speed control starts to move after giving an adverse effect, the operability of turning is impaired.

In view of the above problems, the present disclosure provides a construction machine capable of comfortably performing a turning operation on a slope without causing an adverse effect of a torque component generated by gravity.

The construction machinery of this disclosure is
An upper swivel body with a working machine and
A lower traveling body that rotatably supports the upper swivel body via a swivel shaft, and a lower traveling body.
An electric swivel motor that swivels the upper swivel body and
A rotation speed acquisition unit that acquires a value representing the rotation speed of the upper swing body, and a rotation speed acquisition unit.
A torque command value generator that outputs a torque command value to the electric swivel motor according to the amount of operation of the operation unit, and a torque command value generation unit.
A turning radius acquisition unit that acquires the turning radius of the work machine,
A load weight acquisition unit that acquires the load weight of the work machine,
An inertia acquisition unit that acquires a value representing the reciprocal of the inertia based on the turning radius and the load weight.
A reference angular acceleration calculation unit that calculates a reference angular acceleration that should be generated when the electric swing motor is driven by the torque command value based on the torque command and the reciprocal of the inertia.
A gravity compensation torque calculation unit that calculates a gravity compensation torque for compensating for a torque component generated around the turning axis by gravity based on the deviation between the real angular acceleration obtained from the rotation speed and the reference angular acceleration.
A correction unit that corrects the torque command value with the gravity compensation torque so as to cancel the torque component generated around the turning axis due to gravity.
To be equipped.

In this way, since the feedforward control corrects the torque command value so as to cancel the torque component generated around the turning axis due to gravity, the rotation speed is actually delayed due to the torque component generated by gravity. Even without it, it is possible to control the cancellation in advance.
Nevertheless, the reference angular acceleration that should be generated when the electric swing motor is driven is specified based on the inverse number of inertia and the torque command value determined from the acquired turning radius and load weight, and based on the deviation between the reference angular acceleration and the actual angular acceleration. , Since the gravity compensation torque for canceling the torque component generated around the turning axis due to gravity in the unknown current posture is calculated, even if the current posture changes, the torque component due to the gravity generated in the current posture is appropriately calculated. It becomes possible to cancel.
Therefore, it is possible to comfortably perform a turning operation on a slope without causing an adverse effect of a torque component generated by gravity.

Side view showing the backhoe of the first embodiment Top view showing the backhoe of the first embodiment The figure which shows the electric circuit mounted on the backhoe of 1st Embodiment The figure which shows the turning control controller of 1st Embodiment The figure which shows the turning control controller of 2nd Embodiment The figure which shows the turning control controller of 3rd Embodiment The figure which shows the turning control controller of 4th Embodiment

<First Embodiment>
Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the schematic structure of the backhoe 1 as an example of the hybrid construction machine will be described. The backhoe 1 includes a lower traveling body 11, a working machine 12, and an upper rotating body 13.

The lower traveling body 11 receives power from the engine 2 housed inside the upper rotating body 13 and drives the lower traveling body 11 to travel the backhoe 1. The lower traveling body 11 includes a pair of left and right crawlers 11a and 11a and a pair of left and right traveling motors 11b and 11b. The left and right traveling motors 11b and 11b, which are hydraulic motors, drive the left and right crawlers 11a and 11a, respectively, to enable the backhoe 1 to move forward and backward. Further, the lower traveling body 11 is provided with a blade 11c and a blade cylinder 11d for rotating the blade 11c in the vertical direction.

The work machine 12 is driven by receiving power from the engine 2 to perform excavation work such as earth and sand. The work machine 12 includes a boom 12a, an arm 12b, and a bucket 12c, and by driving these independently, excavation work is possible. The boom 12a, arm 12b, and bucket 12c each correspond to a working portion, and the backhoe 1 has a plurality of working portions.

One end of the boom 12a is supported by the front portion of the upper swing body 13, and the boom 12a is rotated by a boom cylinder 12d that can be expanded and contracted. Further, one end of the arm 12b is supported by the other end of the boom 12a, and the arm 12b is rotated by an arm cylinder 12e that can be expanded and contracted. Then, one end of the bucket 12c is supported by the other end of the arm 12b, and the bucket 12c is rotated by a bucket cylinder 12f that can be expanded and contracted.

The upper swivel body 13 is configured to be swivelable with respect to the lower traveling body 11 via a swivel bearing (not shown) which is a swivel shaft. A cabin 131, a bonnet 132, a counterweight 133, an electric swivel motor 134, an engine 2, and the like are arranged on the upper swivel body 13. The upper swing body 13 is swiveled via a swivel bearing (not shown) by the driving force of the electric swivel motor 134. Further, the motor generator 3 and the hydraulic pump 4 driven by the engine 2 are arranged on the upper swing body 13. The hydraulic pump 4 supplies hydraulic oil to each hydraulic motor and each cylinder.

The cabin 131 is erected on the left side of the upper swing body 13. A driver's seat 131a is arranged in the cabin 131. A pair of work operation levers 131c (see FIG. 3) are arranged on the left and right sides of the driver's seat 131a, and a pair of traveling levers 131b and 131b are arranged in front of the driver's seat 131a. The operator controls the engine 2, each hydraulic motor, each hydraulic cylinder, etc. by operating the work operation lever 131c, the traveling levers 131b, 131b, etc. while seated in the driver's seat 131a, and performs traveling, turning, work, etc. It can be carried out.

A bonnet 132 and a counterweight 133 are vertically arranged at the rear end of the upper swing body 13. The counterweight 133 is erected at the rear end of the upper swing body 13 and covers the engine 2. The bonnet 132 extends upward from the upper end of the counterweight 133 to reach the lower end of the rear wall of the cabin 131, and covers the engine 2 together with the counterweight 133. The rear end portion of the upper swivel body 13 is formed in an arc shape in a plan view, and the bonnet 132 and the counterweight 133 are formed so as to be curved along the rear end portion of the upper swivel body 13. The backhoe 1 of the present embodiment is a so-called rear small turning type.

Next, the configuration of the electric circuit mounted on the backhoe 1 will be described. As shown in FIG. 3, the backhoe 1 includes a swivel control controller 5, an inverter 31, a battery 32, and an electric swivel motor 134. The swivel control controller 5 controls the drive of the electric swivel motor 134 based on the swivel operation amount of the work operation lever 131c (operation unit) and the motor rotation speed [rpm] per unit time. The electric swivel motor 134 is controlled by the swivel control controller 5 via the inverter 31. The electric swivel motor 134 is connected to the battery 32 via the inverter 31. The battery 32 supplies drive energy to the electric swivel motor 134. As shown in FIG. 2, the battery 32 is arranged on the right side of the cabin 131. The inverter 31 controls the electric swivel motor 134. The inverter 31 discharges the electric power of the battery 32 to drive the electric swivel motor 134 based on the torque command value from the swivel control controller 5. The inverter 31 inputs the rotation speed of the electric swing motor 134 per unit time to the swing control controller 5 as a rotation speed acquisition unit. Of course, a separate sensor that detects the rotation speed of the upper swing body 13 may be provided.

Next, the configuration of the turning control controller 5 will be described. As shown in FIG. 4, the turning control controller 5 has a torque command value generation unit 50.

The torque command value generation unit 50 outputs a torque command value to the electric swivel motor 134 according to the amount of operation of the work operation lever 131c, which is an operation unit. The torque command value generation unit 50 is a conventional turning control on a flat ground, and although not described in detail, the target rotation speed determined according to the amount of operation and the actual rotation represented by the motor rotation speed per unit time. The torque command value is output so that there is no deviation from the speed.

In order to cancel the torque component generated by gravity, as shown in FIG. 4, the turning control controller 5 includes a turning radius acquisition unit 60, a load weight acquisition unit 70, an inertia acquisition unit 52, and a reference angular velocity calculation unit 57. It has a gravity compensation torque calculation unit 51 and a correction unit 53.

The gravity compensation torque calculation unit 51 calculates the gravity compensation torque TG_SWING for canceling the torque component generated around the turning axis due to gravity, although the posture is currently unknown. If the current attitude, turning radius, and load weight are all unknown, the gravity compensation torque cannot be calculated. However, in the present embodiment, assuming that the turning radius and the load weight are known, the gravity compensation torque that changes depending on the current posture is calculated. The gravity compensation torque calculation unit 51 calculates the gravity compensation torque based on the deviation between the reference angular acceleration and the actual angular acceleration that should be generated when the electric swivel motor 134 is driven by the torque command value. This calculates the reference angular acceleration that should be generated based on the torque command value currently output to the electric swivel motor 134 by prediction, and if the actual angular acceleration is slower than the predicted reference angular acceleration, it will be in the current posture. It is the effect of gravity according to the current posture, and conversely, it is considered to be the effect of gravity according to the current posture at the earliest. If the deviation of the angular acceleration is eliminated, the true gravity compensation torque according to the current attitude can be calculated.

The correction unit 53 uses the gravity compensation torque calculated by the gravity compensation torque calculation unit 51 to correct the torque command value with the gravity compensation torque so as to cancel the torque component generated around the turning axis due to gravity in the current posture. The addition in the figure is because the gravity compensation torque is calculated as a minus for canceling.

The above is an outline, but will be described in detail next.

The pre-correction torque command calculation unit 54 calculates the torque command value before correction based on the torque command value after correction by the correction unit 53 and the gravity compensation torque used by the correction unit 53. This is because the torque command value used for estimating the reference angular acceleration is calculated by subtracting the gravity compensation torque component from the current torque command value (after correction). The formula is expressed as follows.
Torque command value before correction tTCal [Nm] = Torque command value after correction _i-1 − Gravity compensation torque _i-1
The unit of tTCal is Newton meter. Here, "i-1" is attached to the corrected torque command value and the gravity compensation torque, which means the previous value. i indicates the current time, and i-1 indicates the previous value. Unless otherwise specified, it is the current value.

The phase compensation unit 55 performs a process of delaying the phase of the torque command value before being input to the reference angular acceleration calculation unit 53 that calculates the reference angular acceleration to be generated when the electric swing motor 134 is driven by the torque command value. conduct. It has been found that even if a current corresponding to the torque command value is input to the electric swing motor 134, the desired angular acceleration is not immediately expressed, and the phase (time) is slightly delayed. That is, due to a delay due to communication or a delay due to current control of the inverter, between the swivel motion (angular acceleration) estimated from the torque command value currently instructed and the swirl motion (real angular acceleration) currently detected. The time axis shifts. The phase compensation unit 55 compensates for this time axis (phase) shift. Specifically, in the present embodiment, a low-pass filter is applied to the torque command value. The formula is as follows.
Torque command value after compensation tTCal_Filt = α * tTCal + (1-α) * tTCal_Filt _i-1
In the present embodiment, a low-pass filter is used, but the present invention is not limited to this as long as the torque command value can be delayed.
The phase compensation unit 55 can be omitted although the accuracy is deteriorated.

The viscous friction removing unit 56 removes the viscous friction torque from the torque command value because the viscous friction torque required to maintain the _{motor rotation speed ω SWING [rpm] does not contribute to the increase or decrease of the angular acceleration.} The formula is as follows.
tTVis ＝ K _CVIS × ω _SWING
Torque command value after removal tTCal_Fin ＝ tTCal_Filt − tTVis
Here, K _CVIS is the coefficient of viscous friction. The viscous friction removing portion 56 can be omitted although the accuracy is deteriorated.

The turning radius acquisition unit 60 acquires the turning radius r of the working machine 12. The turning radius acquisition unit 60 of the first embodiment has a turning radius based on the detection results of the position detecting sensor 61 for detecting the positional relationship between the arm 12b and the boom 12a with respect to the upper swinging body 13 and the position detecting sensor 61. It has a turning radius calculation unit 62 for calculating r, and a turning radius calculation unit 62.

The position detection sensor 61 may be, for example, a sensor that detects the stroke positions of the boom cylinder 12d and the arm cylinder 12e, a sensor that detects the angles of the boom 12a and the arm 12b, and detects the acceleration of the boom 12a and the arm 12b. It may be a sensor that does.
For example, when the position detection sensor 61 is a sensor that detects the stroke position, the turning radius calculation unit 62 calculates the boom and arm angles from the respective cylinder positions, and the turning radius r from the boom and arm angles. Is calculated based on forward dynamics.
For example, when the position detection sensor 61 is a sensor that detects the angles of the boom 12a and the arm 12b, the turning radius calculation unit 62 calculates the turning radius r from the angles of the boom and the arm based on forward motion.
For example, when the position detection sensor 61 is a sensor that detects the acceleration of the boom 12a and the arm 12b, the turning radius calculation unit 62 calculates the angle of the boom and the arm from the acceleration of the boom 12a and the arm 12b, and the boom And the turning radius r is calculated from the angle of the arm.

Returning to FIG. 4, the load weight acquisition unit 70 acquires the load weight m of the work machine 12. The load weight acquisition unit 70 of the first embodiment includes a weight measurement sensor 71 for measuring the weight and a load weight calculation unit 72 for calculating the load weight m based on the detection result of the weight measurement sensor 71. Have.

The weight measurement sensor 71 may be, for example, a hydraulic sensor that measures the oil pressure (boom cylinder 12d, arm cylinder 12e, etc.) that drives the work machine 12, or a load cell that measures the weight.

Returning to FIG. 4, the inertia acquisition unit 52 acquires a value representing the reciprocal of the inertia based on the turning radius r acquired by the turning radius acquisition unit 60 and the load weight m acquired by the load weight acquisition unit 70. In the present embodiment, the reciprocal of the inertia is acquired, but the inertia may be acquired and the reciprocal of the inertia may be acquired by calculation. Specifically, the inertia acquisition unit 52 has correlation data in which the reciprocal of the inertia is associated with the load weight m and the turning radius r, and inputs the load weight m and the turning radius r to acquire the reciprocal of the inertia. Correlation data is defined in a table with the load weight m and the turning radius r as inputs.

The reference angular acceleration calculation unit 53 calculates the reference angular acceleration ReferAcc that should be generated when the electric swing motor 134 is driven by the torque command value. Specifically, the angular acceleration ReferAcc is calculated by multiplying the torque command value tTCal_Fin by the reciprocal of the inertia. The formula is as follows.
Angular acceleration ReferAcc = Torque command value tTCal_Fin * Reciprocal of inertia

The angular acceleration deviation calculation unit 58 calculates the deviation DelAcc between the real angular acceleration ActAcc obtained from the value representing the rotation speed (motor rotation speed) and the reference angular acceleration ReferAcc. The real angular acceleration ActAcc is calculated from the forward difference of the motor rotation speed [rpm] as shown in the following equation.
Real Angular Acceleration ActAcc = (ω _SWING − ω _{SWING, i-1} ) / ΔT [s]
Angular Acceleration Deviation DelAcc =-(ActAcc-ReferAcc)

In the present embodiment, the gravity compensation torque calculation unit 51 is a learning unit that newly calculates the gravity compensation torque TG_SWING based on the _{previously calculated gravity compensation torque TG_SWING i-1 and the angular acceleration deviation DelAcc.} As described above, since the gravity compensation torque calculation unit 51 performs the calculation using the gravity compensation torque TG_SWING _i-1 calculated last time, the previous result can be learned and the compensation accuracy can be improved.

Specifically, as shown in the following equation, by executing a learning process that cumulatively integrates the angular acceleration deviation DelAcc multiplied by the gain constant with the previous gravity compensation torque TG_SWING _i-1. Gravity compensation torque TG_SWING is calculated.
Gravity Compensation Torque TG_SWING = Gravity Compensation Torque TG_SWING _i-1 + Gain x Angular Acceleration Deviation DelAcc

In the present embodiment, the gravity compensation torque calculation unit 51 is a learning unit that executes a learning process that cumulatively integrates _{the gravity compensation torque TG_SWING i-1 calculated last time, but the learning process is not executed.} good.
For example, the angular acceleration deviation DelAcc may be multiplied by a conversion coefficient to directly calculate the gravity compensation torque TG_SWING, or a table or function format that outputs the gravity compensation torque TG_SWING with the angular acceleration deviation DelAcc as an input value. It may be.

<Second Embodiment>
The second embodiment will be described. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In the second embodiment, as shown in FIG. 5, the turning radius acquisition unit 60 is configured to acquire a value (set value) preset in the memory as the turning radius r. The load weight acquisition unit 70 is the same as that of the first embodiment. According to this configuration, the device for detecting the turning radius can be omitted, and the cost can be reduced.

<Third Embodiment>
In the third embodiment, as shown in FIG. 6, the load weight acquisition unit 70 is configured to acquire a value (set value) preset in the memory as the load weight m. The turning radius acquisition unit 60 is the same as that of the first embodiment. According to this configuration, the device for detecting the load weight can be omitted, and the cost can be reduced.

<Fourth Embodiment>
In the fourth embodiment, as shown in FIG. 7, the turning radius acquisition unit 60 is configured to acquire a value (set value) preset in the memory as the turning radius r. The load weight acquisition unit 70 is configured to acquire a value (set value) preset in the memory as the load weight m. According to this configuration, the device for detecting the load weight can be omitted, and the cost can be reduced. The device for detecting the turning radius can be omitted, and the cost can be reduced.

As described above, the construction machines of the first to fourth embodiments are
An upper swivel body 13 having a working machine 12 and
A lower traveling body 11 that supports the upper swivel body 13 so as to be swivel via a swivel shaft, and
An electric swivel motor 134 that swivels the upper swivel body 13 and
A rotation speed acquisition unit (inverter 31) that acquires a value representing the rotation speed of the upper swing body 13 and
A torque command value generation unit 50 that outputs a torque command value to the electric swivel motor 134 according to the operation amount of the operation unit, and a torque command value generation unit 50.
A turning radius acquisition unit 60 for acquiring the turning radius r of the work machine 12 and
The load weight acquisition unit 70 that acquires the load weight m of the work machine, and
An inertia acquisition unit 52 that acquires a value representing the reciprocal of the inertia based on the turning radius r and the load weight m.
Based on the torque command and the reciprocal of the inertia, the reference angular acceleration calculation unit 53 that calculates the reference angular acceleration ReferAcc that should be generated when the electric swing motor 134 is driven by the torque command value, and
Based on the deviation between the real angular acceleration ActAcc and the reference angular acceleration ReferAcc obtained from the rotation speed, the gravity compensation torque calculation unit 51 that calculates the gravity compensation torque TG_SWING for compensating the torque component generated around the turning axis due to gravity, and the gravity compensation torque calculation unit 51.
A correction unit 53 that corrects the torque command value with the gravity compensation torque TG_SWING so as to cancel the torque component generated around the turning axis due to gravity.
To be equipped.

In this way, since the feedforward control corrects the torque command value so as to cancel the torque component generated around the turning axis due to gravity, the rotation speed is actually delayed due to the torque component generated by gravity. Even without it, it is possible to control the cancellation in advance.
Nevertheless, the reference angular acceleration ReferAcc that should be generated when the electric swing motor 134 is driven is specified based on the inverse number of inertia and the torque command value determined from the acquired turning radius r and the loaded weight m, and the reference angular acceleration ReferAcc and the actual angular acceleration are specified. Based on the deviation from ActAcc, the gravity compensation torque TG_SWING is calculated to cancel the torque component generated around the turning axis due to gravity in the unknown current posture, so even if the current posture changes, it will be generated in the current posture. It is possible to appropriately cancel the torque component due to gravity.
Therefore, it is possible to comfortably perform a turning operation on a slope without causing an adverse effect of a torque component generated by gravity.

In the third or fourth embodiment, the load weight acquisition unit 70 acquires a preset value as the load weight m.

In the case of a construction machine in which the load weight m of the work machine 12 does not change much, by setting a preset value as the load weight m, the device for detecting the load weight can be omitted, and the cost can be reduced. ..

In the second or fourth embodiment, the turning radius acquisition unit 60 acquires a preset value as the turning radius r.

In the case of a construction machine in which the boom of the work machine or the extension of the arm does not change much, the device for detecting the turning radius can be omitted by setting the preset value as the turning radius r, and the cost can be reduced. Become.

In the first or third embodiment, the working machine 12 has a boom 12a rotatably supported by the upper swing body 13 and an arm 12b rotatably supported by the boom 12a. The turning radius acquisition unit 60 calculates the turning radius r based on the position detection sensor 61 for detecting the positional relationship between the arm 12b and the boom 12a with respect to the upper swinging body 13 and the detection result of the position detecting sensor 61. It has a radius calculation unit 62 and.

According to this configuration, since the position detection sensor 61 detects the positional relationship between the arm 12b and the boom 12a with respect to the upper swing body 13, the turning radius r can be calculated, and the actual change in the extension of the arm 12b and the boom 12a can be calculated. Correspondingly, the torque component generated by gravity can be compensated, and the compensation accuracy can be improved.

In the first or second embodiment, the load weight acquisition unit 70 calculates the load weight based on the detection results of the weight measurement sensor 71 for measuring the weight and the weight measurement sensor 71, and the load weight calculation unit 72. And have.

According to this configuration, the load weight m can be calculated by the weight measurement sensor 71 such as a hydraulic sensor or a load cell and the load weight calculation unit 72, and the gravitational torque that changes according to the change of the load weight m can be compensated, and the compensation accuracy can be improved. It is possible to improve.

In the first to fourth embodiments, the gravity compensation torque calculation unit 51 executes a learning process for accumulating a value based on the deviation DelAcc with respect to _{the previously calculated gravity compensation torque TG_SWING i-1, thereby performing gravity compensation.} Calculate the torque TG_SWING newly.

In this way, since the _{value based on the deviation DelAcc is cumulatively integrated with the gravity compensation torque TG_SWING i-1} calculated last time, the previous result can be learned and the compensation accuracy can be improved.

In the first to fourth embodiments, the phase compensation unit 55 is provided to perform a process of delaying the phase of the torque command value before the torque command value is input to the reference angular acceleration calculation unit 53.

Between the turning motion estimated from the torque command value currently instructed (reference angular acceleration ReferAcc) and the currently detected turning motion (real angular acceleration ActAcc) due to the delay due to communication or the delay due to the current control of the inverter. Time axis shift occurs. However, in this way, it is possible to compensate for the deviation of the time axis by the process of delaying the phase of the torque command value, and it is possible to improve the accuracy of control by aligning both time axes.

Although the embodiments of the present disclosure have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present disclosure is shown not only by the description of the above-described embodiment but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

It is possible to adopt the structure adopted in each of the above embodiments in any other embodiment.

1 Backhoe (construction machinery)
11 Lower traveling body 12 Working machine 13 Upper turning body 131c Work operation lever (operation unit)
134 Electric swivel motor 31 Inverter (rotation speed acquisition unit)
50 Torque command value generation unit 51 Gravity compensation torque calculation unit 52 Inertia acquisition unit 53 Correction unit 55 Phase compensation unit 57 Reference angular acceleration calculation unit 60 Swing radius acquisition unit 61 Position detection sensor 62 Swing radius calculation unit 70 Loading weight acquisition unit 71 Weight measurement sensor 72 Load weight calculation unit

Claims (7)

An upper swivel body with a working machine and
A lower traveling body that rotatably supports the upper swivel body via a swivel shaft, and a lower traveling body.
An electric swivel motor that swivels the upper swivel body and
A rotation speed acquisition unit that acquires a value representing the rotation speed of the upper swing body, and a rotation speed acquisition unit.
A torque command value generator that outputs a torque command value to the electric swivel motor according to the amount of operation of the operation unit, and a torque command value generation unit.
A turning radius acquisition unit that acquires the turning radius of the work machine, and
A load weight acquisition unit that acquires the load weight of the work machine,
An inertia acquisition unit that acquires a value representing the reciprocal of the inertia based on the turning radius and the load weight.
A reference angular acceleration calculation unit that calculates a reference angular acceleration that should be generated when the electric swing motor is driven by the torque command value based on the torque command and the reciprocal of the inertia.
A gravity compensation torque calculation unit that calculates a gravity compensation torque for compensating for a torque component generated around the turning axis by gravity based on the deviation between the real angular acceleration obtained from the rotation speed and the reference angular acceleration.
A correction unit that corrects the torque command value with the gravity compensation torque so as to cancel the torque component generated around the turning axis due to gravity.
With construction machinery. The construction machine according to claim 1, wherein the load weight acquisition unit acquires a preset value as the load weight. The construction machine according to claim 1, wherein the turning radius acquisition unit acquires a preset value as the turning radius. The working machine has a boom rotatably supported by the upper swing body and an arm rotatably supported by the boom.
The turning radius acquisition unit calculates a turning radius by calculating a turning radius based on a position detection sensor for detecting the positional relationship between the arm and the boom with respect to the upper swinging body and the detection result of the position detecting sensor. The construction machine according to claim 1 or 2, which has a part and a portion. The load weight acquisition unit includes a weight measurement sensor for measuring the weight and a load weight calculation unit for calculating the load weight based on the detection result of the weight measurement sensor, according to claim 1 or 3. Described construction machinery. The gravity compensation torque calculation unit newly calculates the gravity compensation torque by executing a learning process for accumulating a value based on the deviation with respect to the gravity compensation torque calculated last time. The construction machine according to any one of ~ 5. The construction machine according to any one of claims 1 to 6, further comprising a phase compensating unit that performs a process of delaying the phase of the torque command value before the torque command value is input to the reference angular acceleration calculation unit.

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