JP6706974B2 - Active damping device and control method of active damping device - Google Patents

Description

The present invention relates to an active vibration damping device and a control method for the active vibration damping device.

Conventionally, various research and development have been carried out on a vibration damping device. In particular, in transportation equipment, it is a mission to deliver the objects to be transported to the destination while they are still loaded, and for that reason, suspension, which is a type of vibration damping device that passively absorbs vibrations, is an air suspension, etc. , Various innovations and developments have been made. These were able to absorb small vibrations coming from the road surface, but could not absorb large undulations of the road surface, as well as large shaking when passing through curves, starting and stopping, slopes, and the like.
In addition, gas tanks installed on the coast have a problem that internal liquid leaks due to a sloshing phenomenon caused by an earthquake or the like.

In addition, studies are being conducted to suppress the vibration applied to an object mounted on a moving body due to the movement of the moving body such as transportation equipment by a vibration damping device installed on the moving body. The vibration damping device actively absorbs the vibration applied to the load, so that the load can be safely transported without damaging the load.

For example, Patent Document 1 (Japanese Patent Laid-Open No. 2011-52738) discloses a multi-degree-of-freedom active vibration damping device capable of expanding the maximum damping force and the maximum damping torque that can act on a damping target. There is.

The multi-degree-of-freedom active vibration damping device disclosed in Patent Document 1 is a three-axis direction vibration damping device that cancels a three-degree-of-freedom linear vibration or a three-degree-of-freedom linear vibration and a three-degree-of-freedom rotational vibration that occur in a vibration damping target. In a multi-degree-of-freedom active vibration damping device that applies a force and a vibration damping torque in three axial directions to the vibration damping target, a base plate attached to the vibration damping target and one end of the base plate are displaced. Six linear motion links that are fixed by restraint and are capable of expanding and contracting in predetermined directions, movable masses supported by the other end of each linear motion link and displacement constraint, and the amount of expansion and contraction of each linear motion link are detected. Displacement detecting means, vibration detecting means for detecting a vibration component generated in the vibration suppression target, and the amount of expansion and contraction detected by the displacement detecting means and the vibration component detected by the vibration detecting means Control means for controlling the expansion and contraction operation, and arranging the fixed points of the respective linear motion links to the base plate and the movable mass so that the distance between the base plate and the movable mass becomes small. It is characterized by.

Further, Patent Document 2 (Japanese Patent Laid-Open No. 2007-10878) discloses that the height of the rocking table device and the rocking/stabilizing table device can be set low, and the size of the entire device is reduced.

The rocking table device described in Patent Document 2 includes a base, a top plate that is supported by a support portion provided on the base and is tiltable about two orthogonal axes, and is tilted between the base and the top plate. And a plurality of actuators that are arranged radially with respect to the center of the top plate and have one end connected to the base via a universal joint and the other end connected to the top plate, and the one orthogonal shaft. A first signal generator that outputs a first rotation signal that rotates the top plate around the first plate, and the first rotation signal that the first signal generator outputs are arranged on one side of the one shaft. A first signal output section that supplies the inverted signal of the first rotation signal to the actuator that is arranged on the other side of the one shaft, and the above-mentioned around the other shaft that is orthogonal to the actuator. A second signal generator that outputs a second rotation signal that rotates the top plate, and the actuator that is arranged on one side of the other shaft based on the second rotation signal output by the second signal generator. And a second signal output section for applying an inversion signal of the second rotation signal to the actuator arranged on the other side of the other shaft.

Further, Japanese Patent Laid-Open No. 2005-88742 discloses a swing control device for a swing type vehicle that controls the swing angle of the vehicle body without being affected by the inclination of the road surface.

A swing control device for a swing-type vehicle described in Patent Document 3 is a force applied to a swing-side vehicle body or a non-swing-side vehicle body in a swing control device for a three-wheel or four-wheel swing vehicle in which a vehicle body swings. Is detected, and the relative swing angle between the rocking side vehicle body and the non-rocking side vehicle body is controlled according to the detected angle.

In addition, Patent Document 4 (Japanese Patent Laid-Open No. 2001-163098) ensures lateral acceleration (horizontal acceleration in a plane perpendicular to the traveling direction of an automobile) even for infants and persons with disabilities. There is disclosed a tilt control device for an automobile seat, which is capable of being supported by the above.

In the tilt control device for a vehicle seat described in Patent Document 4, the acceleration applied to at least a part of the seats other than the driver seat of the running car in a horizontal direction in a plane perpendicular to the running direction of the car. Of the seat surface of the seat so that the seat surface of the seat is substantially perpendicular to the direction of acceleration acting on the seat in a plane perpendicular to the traveling direction. It controls the inclination.

Further, Patent Document 5 (Japanese Patent Laid-Open No. 2009-259264) discloses a vibration suppression control system for a transfer that prevents vibrations that occur in a transfer object during transfer, and that is easy to design a control system and derive a controller. -A dubbed controller is disclosed.

The feedback controller of the vibration suppression control system for conveyance described in Patent Document 5 is a feedback controller for the vibration suppression control system for conveyance, which has at least a notch filter or a low-pass filter. In order to limit the combination of the frequency control element and the position control element to have, and to give the value of the element of the feedback controller optimally, the design specification is given by both the frequency specification and the time specification.

Further, in Patent Document 6 (JP 2001-32878A), the sloshing natural frequency is changed and the natural frequency is changed by changing and synchronizing the sloshing cycle according to the cycle of the main vibration system. A tuned sloshing damper with a wide range of use that can obtain optimum vibration suppression even for a structure that is used is disclosed.

A tuning sloshing damper having a wide use range described in Patent Document 6 damps a container in which an electrorheological fluid whose apparent viscosity changes according to a change in an electric field is contained and an electrorheological fluid in the container. Electric field applying means for applying an electric field according to the natural frequency of the structure to be formed.

Further, in Patent Document 7 (Japanese Patent Laid-Open No. 9-10924), the problem of sloshing of the molten metal when the pouring device is moved is completely solved, and the molten metal overflows from the ladle, or the air or noro It discloses a pouring method that prevents the deterioration of product quality due to contamination (molten metal contamination) due to entrainment of iron.

The pouring method described in Patent Document 7 is a pouring method in which a molten metal is held in a ladle, the ladle is conveyed to a pouring position by a conveying means, and tilted so that the molten metal is poured into a mold frame. When transferring the ladle to the pouring position, the ladle transfer is stopped by performing stepwise switching control of the acceleration/deceleration curve in each region of the acceleration region when the ladle starts to be transferred and the deceleration region when the transfer is stopped. It suppresses the vibration of the liquid level in the later ladle.

JP, 2011-52738, A JP, 2007-10878, A JP, 2005-88742, A JP 2001-163098 A JP, 2009-259264, A JP 2001-32878A JP, 9-10924, A

In Patent Document 1 described above, vibration is provided by giving vibration to the movable mass that cancels linear vibration with three degrees of freedom and rotational vibration with three degrees of freedom. In Patent Document 2, vibration is performed by detecting the roll and pitch of the base with an inclination sensor and moving the top plate in the opposite direction. In Patent Document 3, rocking control is performed by capturing the road surface inclination of a three-wheeled or four-wheeled motorcycle. In Patent Document 4, the acceleration sensor controls the inclination of the seat surface so as to be perpendicular to the direction of the total acceleration acting on the seat.

Further, in Patent Document 5, in a system for preventing vibration generated in a conveyed object during conveyance, a sloshing characteristic is identified and controlled by using a notch filter or a low-pass filter. In Patent Document 6, a tuned sloshing damper that changes the natural frequency of the sloshing is realized by changing the sloshing cycle according to the cycle of the vibration system using magnetic fluid and performing tuning. Further, in Patent Document 7, the sloshing problem of the molten metal when the pouring device is moved is solved.

However, in any of the above-mentioned documents, the control is performed by identifying the simulation calculated in advance, but there is a problem that the vibration cannot be suppressed unless the conditions are satisfied.

An object of the present invention is to provide an active vibration damping device and a control method for the active vibration damping device, which are capable of damping the main swing.

(1)
An active vibration damping device according to one aspect is an active vibration damping device that damps a swing applied to a liquid by an actuator, and includes a loading platform on which a liquid is placed and a vertex position of a polygon under a loading platform surrounding a center of gravity of the loading platform. Each of the actuators, a load sensor that detects the load applied to the actuator, and a control unit that controls the actuator based on the data from the load sensor, and the control unit uses the load sensor to change the liquid level of the liquid. Is detected and the load sensor control for suppressing the water level change is performed.

The present inventor has found that the change in the water level of the liquid can be detected from the data of the load sensor. As a result, based on the change in the data of the load sensor, the actuator can be driven to suppress the main swing and suppress the change in water level.

(2)
An active vibration damping device according to a second aspect of the present invention is the active vibration damping device according to one aspect, wherein the control section causes the actuator to move downward when the change in the water level of the liquid in the upper part of the one actuator and the load sensor tends to increase. The load sensor control may be performed by operating the actuator in the ascending direction when the change in the water level of the liquid in the upper part of the one actuator and the load sensor has a downward tendency.

In this case, when the change in the liquid level of the liquid tends to rise, the actuator is moved in the descending direction, so that the potential energy of the liquid can be reduced. Further, when the change in the water level of the liquid tends to decrease, the actuator is moved in the upward direction, so that the potential energy of the liquid can be increased.
As a result, it is possible to suppress the change in water level due to the rocking of the liquid.

(3)
An active vibration damping device according to a third aspect of the present invention is the active vibration damping device according to one aspect or the second aspect of the present invention, wherein an acceleration detecting unit that detects an acceleration applied to the liquid and an acceleration detected by the acceleration detecting unit The control unit further includes a filter unit that cuts a frequency component exceeding twice the natural frequency of the object, and the control unit controls the actuator so that the acceleration direction of the frequency component passing through the filter unit is perpendicular to the liquid. You may perform the acceleration control to control and the load sensor control which suppresses the water level change by a load sensor.

In this case, the filter section cuts off the frequency component that exceeds twice the natural frequency of the object detected by the acceleration detecting section. Then, the control unit controls so that the direction of the acceleration of the frequency component subjected to the cut processing is perpendicular to the object.
As a result, it is possible to mainly suppress the primary resonance frequency of the object by cutting the frequency component that is more than twice the natural frequency. Therefore, by focusing on a frequency component that is equal to or less than twice the natural frequency and performing control, it is possible to reliably suppress the main swing of the object in the moving body.

(4)
An active vibration damping device according to a fourth aspect is the active vibration damping device according to the third aspect, wherein the control unit performs acceleration control when the acceleration exceeds a predetermined value, and when the acceleration is equal to or less than the predetermined value. Alternatively, the load sensor control may be performed.

When the acceleration exceeds the predetermined value, the acceleration control is performed, and when the acceleration is equal to or less than the predetermined value, the load sensor control is performed. Therefore, it is possible to reliably suppress the water level change due to the rocking.
The predetermined value is a water surface angle of several degrees, ±1 degree, ±2 degrees, ±3 degrees, ±4 degrees, ±5 degrees, ± when the water surface angle is estimated from the pitch and the roll by the acceleration sensor. It is either 6 degrees, ±7 degrees, ±8 degrees, or ±9 degrees.

(5)
An active vibration damping device according to a fifth aspect of the present invention is the active vibration damping device according to the third aspect of the present invention, wherein the control unit controls the control amount for acceleration control and the control amount for load sensor control within a predetermined range of acceleration. You may change it.

In this case, the control amount of the acceleration control and the control amount of the load sensor control may be linearly changed or may be changed in a quadratic curve within a predetermined range of acceleration.
Specifically, the control amount of the acceleration control may be decreased from the upper limit side within the predetermined range toward zero, and the control amount of the load sensor control may be increased from the upper limit side within the predetermined range toward zero.
Further, the control amount of the acceleration control may be increased from the lower limit side within the predetermined range toward zero, and the control amount of the load sensor control may be decreased toward the zero side from the lower limit side within the predetermined range.
The predetermined range is any of ±1 degree, ±2 degrees, ±3 degrees, ±4 degrees, ±5 degrees, ±6 degrees, ±7 degrees, ±8 degrees, or ±9 degrees. ..

(6)
An active vibration damping device according to a sixth aspect of the present invention is the active vibration damping device according to the fourth or fifth aspect of the invention, wherein the control unit has a case where the acceleration changes from a positive predetermined value to zero within a predetermined range. The hysteresis control may be performed by changing the control amount when the negative predetermined value changes to zero.

In this case, when the water surface angle moves from positive to negative, the control unit sets the positive predetermined value to +1 degree, sets the negative predetermined value to -2 degrees, and moves the water surface angle from negative to positive. In this case, the negative predetermined value may be set to -1 degree and the positive predetermined value may be set to +2 degrees.
The value is not limited to an integer, and may be a value in 0.1 degree increments.

(7)
An active vibration damping device according to a seventh aspect of the present invention is the active vibration damping device according to the third aspect of the present invention, wherein the control unit superimposes the control amount for acceleration control and the control amount for load sensor control at a constant ratio. Good.

As a result, the control amount of the acceleration control and the control amount of the load sensor control can be superimposed, and the change in the water level of the liquid can be efficiently suppressed.

(8)
A control method for an active vibration damping device according to another aspect is a method for controlling an active vibration damping device in which vibrations applied to a liquid in a cargo bed are damped by an actuator, wherein An actuator step of moving the actuators respectively arranged at the apex positions, a load sensor step of detecting a load applied to the actuator, and a control step of controlling the actuator of the actuator step based on the data from the load sensor step. The control step carries out a load sensor control step of detecting a water level change of the liquid by the load sensor step and controlling the actuator so as to suppress the water level change.

The present inventor has found that the change in the water level of the liquid can be detected from the data of the load sensor. As a result, the actuator can be driven based on the change in the data of the load sensor to suppress the main swing, and the change in the water level can be suppressed.

(A)
In the active vibration damping device according to the present invention, the moving body may have a loading platform, the object may be placed on the loading platform, and the actuators may be arranged at the respective vertex positions of the polygon below the loading platform surrounding the center of gravity.

In this case, the actuators are respectively arranged at the apex positions of the polygons in the lower part of the loading platform surrounding the center of gravity of the loading platform of the moving body. For example, when the polygon is a triangle, a minimum of three actuators are arranged, and when the polygon is a quadrangle, four actuators are arranged, and the polygon is n (n is an arbitrary number). In the case of a square), n actuators are arranged. As a result, it is possible to reliably control the swing of the loading platform.

(B)
The active vibration damping device according to the invention may further include a setting unit capable of arbitrarily setting the natural frequency of the object.

In this case, the natural frequency of the object can be arbitrarily set by the setting unit. As a result, the target swing (vibration) can be easily suppressed.

(C)
The active vibration damping device according to the invention estimates the natural frequency of an object from the behavior detection unit that preliminarily operates the actuator to detect the behavior of the object before the operation of the moving body, and the behavior of the object detected by the behavior detection unit. The control unit may control the actuator according to the natural frequency estimated by the estimation unit.

In this case, the behavior detection unit can preliminarily operate the actuator before operating the moving body. Moreover, the natural frequency of the object can be estimated by performing preliminary operation. As a result, the control unit can appropriately control the swing (vibration) at any time even when the content of the object or the object itself changes.
Specifically, the sloshing phenomenon and the like can be suppressed.

(D)
In the active vibration damping device according to the invention, the behavior detection unit may be composed of a load sensor that detects a load applied to the actuator or an imaging device that images an object.

In this case, the behavior detection unit may include a load sensor or an imaging device. As a result, the behavior of the object can be reliably detected. For example, when the object is an individual, the shaking of the individual can be detected, and even when the object is a liquid, the shaking of the liquid can be detected.

(E)
A method for controlling an active vibration damping device according to another aspect is a method for controlling an active vibration damping device in which an actuator suppresses a swing applied to an object mounted on a moving body, and an acceleration detection for detecting an acceleration applied to the object. Of the accelerations detected by the acceleration detection step and the step of filtering the frequency components that exceed twice the natural frequency of the object, and the direction of the acceleration of the frequency components passing through the filtering step is perpendicular to the object. And a control step for controlling the actuator.

In this case, the frequency component exceeding twice the natural frequency of the object detected by the acceleration detection process is cut by the filtering process. Then, the control process performs control so that the direction of the acceleration of the frequency component subjected to the cut processing becomes perpendicular to the object.
As a result, it is possible to mainly suppress the primary resonance frequency of the object by cutting the frequency component that is more than twice the natural frequency. Therefore, by focusing on a frequency component that is equal to or less than twice the natural frequency and performing control, it is possible to reliably suppress the main swing of the object in the moving body.

It is a schematic diagram which shows an example which applied the active vibration damping apparatus concerning this Embodiment to the bed of an automobile. It is a schematic diagram which shows an example of the active vibration damping device of FIG. It is a schematic diagram which shows an example of a structure of an active vibration damping device. It is a figure which shows the correlation of a load sensor and a water level change. It is a flow chart which shows an example of control concerning this embodiment. It is a flow chart which shows an example of behavior detection processing. It is a flow chart which shows an example of control processing of Step S3. It is a schematic diagram which shows an example of the control processing concerning this Embodiment. It is a flow chart which shows an example of acceleration control processing. It is a flow chart which shows an example of load sensor control processing. It is a schematic diagram which shows the other example of the control processing concerning this Embodiment. It is a schematic diagram which shows the further another example of the control processing concerning this Embodiment. It is a schematic diagram which shows the further another example of the control processing concerning this Embodiment. It is a schematic diagram which shows an example which applied the active damping apparatus concerning 2nd Embodiment to the liquid tank.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Further, in the case of the same symbols, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(First embodiment)
First, FIG. 1 is a schematic diagram showing an example in which the active vibration damping device 100 according to the present embodiment is applied to a luggage carrier 550 of an automobile, and FIG. 2 is a schematic diagram showing an example of the active vibration damping device 100 in FIG. FIG. 3 is a schematic diagram showing an example of the configuration of the active vibration damping device 100 of FIGS. 1 and 2.

As shown in FIG. 1, the active vibration damping device 100 is applied to an automobile 500. Active vibration damping device 100 is arranged between the main body of automobile 500 and luggage carrier 550. The automobile 500 according to the present embodiment is an example of a live fish carrier.

Next, a specific example of the active vibration damping device 100 will be described.
As shown in FIGS. 2 and 3, the active vibration damping device 100 includes an actuator 140, a load sensor 145, an acceleration sensor 300, a setting unit 310, a low pass filter 320, and a control unit 400.

The actuator 140 includes an actuator 110, an actuator 120, and an actuator 130.
The load sensor 145 includes a load sensor 115, a load sensor 125, and a load sensor 135.
The cylinder of the actuator 110 is provided with a load sensor 115, the cylinder of the actuator 120 is provided with a load sensor 125, and the cylinder of the actuator 130 is provided with a load sensor 135.

Next, as shown in FIG. 2, the traveling direction of the automobile 500 is assumed to be the x direction, the right direction of the automobile 500 is assumed to be the y direction, and the vertically upward direction of the automobile 500 is assumed to be the z direction. Further, the clockwise direction of the x-axis is assumed to be the roll direction, and the clockwise direction of the y-axis is assumed to be the pitch direction.

In the present embodiment, actuator 130 is arranged in the x direction of the traveling direction of automobile 500, and actuator 110 and actuator 120 are provided at regular intervals in the opposite direction to the x direction of the traveling direction of automobile 500.
Further, the actuator 120 is provided to the left of the automobile 500 (on the side opposite to the y direction), and the actuator 110 is provided to the right of the automobile 500 (on the y direction side).

Therefore, as shown in FIG. 2, the piston rod sides of the actuators 110, 120, 130 are arranged at the vertices Aa, Ab, Ac of the isosceles triangle with respect to the lower surface of the loading platform 550, respectively. The angle Θ between the sides Aa-Ac and Aa-Ab of the isosceles triangle is Θ=π/3, and the angle Θ between the sides Ab-Ac and Aa-Ab of the isosceles triangle is Θ=π/. It is 3.
The cylinder sides of the actuators 110, 120, and 130 are provided on the main body of the automobile 500 at the vertices of an isosceles triangle larger than the above-described isosceles triangle.

As a result, the actuators 110, 120, 130 are provided with a predetermined angle, for example, within a range of 1 degree to 40 degrees, for example, tilted by 5 degrees.
The main body of the automobile 500 mentioned above means a frame, a lower part of the bed 550, an axle, or the like.

Further, the load sensor 115 provided on the cylinder of the actuator 110, the load sensor 125 provided on the cylinder of the actuator 120, and the load sensor 135 provided on the cylinder of the actuator 130 can detect the load of the platform 550, respectively. ..

An acceleration sensor 300 is provided at the center of gravity Ag of the isosceles triangle Aa, Ab, Ac.

Further, on the loading platform 550 according to the present embodiment shown in FIGS. 1 and 2, a water tank containing seawater, fresh fish and the like is loaded.
For example, when the automobile 500 provided with the active vibration damping device 100 is a live fish carrier, the sloshing phenomenon of water in the aquarium that is the loading platform 550 is reduced, the fish in the aquarium can be transported without causing fatigue, and the fish bodies It is possible to prevent mortality due to rubbing and increase the survival rate, and to prevent deterioration in commercial value due to rubbing. In addition, the transportation efficiency can be improved by increasing the average traveling speed of the automobile 500.

Further, in the present embodiment, the automobile 500 is the live fish carrier, but the present invention is not limited to this, and other medical equipment, optical equipment, inspection and measurement equipment, semiconductor manufacturing equipment, and other precision equipment can be safely and securely used. It may be a vehicle for transporting precision equipment to be transported to a vehicle, a vehicle for animals such as pets and racehorses, a vehicle for delicate food such as strawberries and melons, or any other vehicle. Further, in the fields of medical care and nursing care, it can be mounted on an ambulance or a welfare vehicle to reduce the influence on an emergency patient and a person requiring care and can be transported.

Next, FIG. 4 is a diagram showing the correlation of the water level changes of the load sensors 115, 125, 135 and the platform 550. The vertical axis of FIG. 4 represents the amplitude or the sensitivity of the load sensors 115, 125, 135, and the horizontal axis represents time. The water level change was measured by attaching a liquid level sensor to the center of each side of the upper end of the loading platform 550.

Change A in FIG. 4 is obtained by doubling the load sensor 135 and offsetting the origin. Change B is the sum of the load sensor 115 and the load sensor 125. Change C and change D are the measurement results of the liquid level sensor.

As shown in FIG. 4, the inventor has found that the phases of the change A and the change C coincide with each other and the magnitude ratio of the amplitude appears constant. Further, the inventor has found that the phases of the change B and the change D coincide with each other, and the magnitude ratio of the amplitude appears constant.
As a result, they have found that it is possible to observe the water level change using the load sensors 115, 125, 135.

(Control flow chart)
FIG. 5 is a flowchart showing an example of control according to this embodiment.

As shown in FIG. 5, the control unit 400 determines whether or not a predetermined event has occurred (step S1). Here, the predetermined event is a case where the engine of the automobile 500 is started. That is, it is determined that a predetermined event has occurred when the engine is started. It should be noted that when the engine is started after the engine is started, it is determined that the predetermined event has not occurred.

When it is determined that the predetermined event has occurred, the control unit 400 performs a behavior detection process described later (step S2).
On the other hand, when it is determined that the predetermined event has not occurred, the control unit 400 performs the control process described later (step S3).

Then, when the process of step S2 or step S3 is completed, the process returns to step S1 and the process is repeated.

In the present embodiment, the processing from step S1 to step S3 is repeated, but the processing may be stopped when the engine is turned off.
Further, in the present embodiment, the predetermined event is that the engine of the automobile 500 is switched on, but the present invention is not limited to this, and may be a change over time of the load sensor 145. After stopping the engine, it may be automatically performed after a predetermined time from starting the engine, for example, 5 minutes after starting the engine, or even when the drive gear is in the D range. Etc. may be provided and the switch is turned on, or any other condition may be satisfied.

As a result, even when the amount of fresh fish and the amount of seawater in the loading platform 550 of the automobile 500 decreases, the behavior detection control process of step S2 can be performed each time, and thus the vibration of the loading platform 550 can be suppressed appropriately.

(Behavior detection processing)
Next, the behavior detection process of the active vibration damping device 100, which is an example of the flowchart shown in FIG. 5, will be described.

FIG. 6 is a flowchart showing an example of the behavior detection processing.
As shown in FIG. 6, the control unit 400 of the active vibration damping device 100 forcibly applies a small vibration to the platform 550 by the actuator 140 (step S21).
Specifically, the actuators 110, 120, and 130 apply vibrations having a frequency of 0.5 Hz or more and 2 Hz or less to the platform 550 for about 2 seconds.

Next, the setting unit 310 detects the vibration of the loading platform 550 with the load sensor 145 (step S22).
The setting unit 310 estimates the primary natural frequency of the load on the loading platform 550 from the vibration of the loading platform 550 detected by the load sensor 145 (step S23).
In the present embodiment, the primary natural frequency for water in the water tank is estimated.

Next, the setting unit 310 estimates the secondary natural frequency from the estimated primary natural frequency (step S24). When the secondary natural frequency is detected by the load sensor 145, the setting unit 310 adopts the detected secondary natural frequency.

Subsequently, the setting unit 310 sets the low-pass filter 320 so as to cut off the frequency component exceeding the secondary natural frequency (step S25).

The acceleration obtained from the acceleration sensor 300 is made into only the frequency component of the secondary natural frequency or lower by the low pass filter 320, and is given to the control unit 400.
The control unit 400 operates the actuator 140 to control the luggage carrier 550 based on only the frequency components having the secondary natural frequency or less, as will be described later.

Note that, in this embodiment, the frequency is changed to vibrate with a small amplitude to vibrate, but the invention is not limited to this, and vibrates in a harmonic range, or vibrates in an arbitrary frequency range, or It suffices if the primary natural frequency can be detected or estimated, for example, by applying an impulse (light impact) using an actuator.

Further, in the present embodiment, the vibration is detected by the load sensor 145 in the process of step S22, but the present invention is not limited to this, and an imaging device, a camera or the like capable of imaging from above the luggage carrier 550 is used. , Image processing may be performed, and detection may be performed by any other method.

(Control processing)
Next, the control process of step S3 shown in FIG. 5 will be described. In the present embodiment, the water surface angle between the pitch and the roll is estimated, the load sensor control is performed when the control angle is within ±1 degree, and the acceleration control is performed when the control angle exceeds ±1 degree. To do.

FIG. 7 is a flowchart showing an example of the control process of step S3, and FIG. 8 is a schematic diagram showing an example of the control process according to the present embodiment.

As shown in FIGS. 7 and 8, the control unit 400 determines whether or not the control angle of acceleration damping is within a range of ±1 degree or less (step S101). Next, when the control unit 400 determines that the control angle for acceleration damping is in the range of exceeding ±1 degree, the control unit 400 performs acceleration damping control (step S102). On the other hand, when the control unit 400 determines that the control angle for acceleration damping is in the range of ±1 degree or less, the control unit 400 performs the load sensor control (step S103).
Hereinafter, the acceleration control will be described, and then the load sensor control will be described.

(Acceleration control)
FIG. 9 is a flowchart showing an example of the acceleration control process of step S102.

As shown in FIG. 9, the control unit 400 receives the accelerations of the three axes of the x-axis, the y-axis, and the z-axis from the acceleration sensor 300 (step S31).
Since the signal received by the control unit 400 is received not directly from the acceleration sensor 300 but through the low-pass filter 320, the signal cut at the cutoff frequency is given to the control unit 400.

Subsequently, the control unit 400 performs AD (analog-digital, hereinafter simply referred to as AD) conversion of the received acceleration signal (step S32).
The sampling frequency according to this embodiment is 10 Hz, that is, the sampling cycle of each acceleration is 0.1 sec. Further, the control cycle in the control unit 400 is 0.5 sec.

Hereinafter, specifically, the acceleration input from the acceleration sensor 300 is assumed to be Ain.
Further, the acceleration on the x-axis is defined as Axin, the acceleration on the y-axis is defined as Ayin, and the acceleration on the z-axis is defined as Azin.
Since the acceleration Ain input from these acceleration sensors 300 includes a noise component with respect to the shaking of the water surface, the low-pass filter 320 performs low-pass processing (step S33). Here, the acceleration after the low-pass processing is defined as Afilter.

Here, the low-pass filter 320 is a fourth-order FIR (Finite Impulse Response) filter.

Here, assuming that n=4 and the filter coefficient,

It means that the acceleration at the n time point of the above equation 2 is calculated from the data from the n time point up to four points before the unit time. Therefore, the above low-pass filter has a cut-off frequency of 1 Hz because the sampling period is 0.1 sec.

Next, the liquid surface angle Θ in the loading platform 550 is calculated from the AD-converted acceleration Afilter (step S34).
If the X-axis acceleration is defined as Ax, the Y-axis acceleration is defined as Ay, and the Z-axis acceleration is defined as Az, the roll surface liquid surface angle Θ roll is expressed by the following equation.

Further, the liquid surface angle ΘPitch in the pitch direction is represented by the following formula.

The control unit 400 performs the mechanism conversion based on the liquid surface angle Θroll in the roll direction and the liquid surface angle ΘPitch in the pitch direction described above (step S35).
Next, the control unit 400 gives the control signal subjected to the mechanism conversion to the actuators 110, 120 and 130 (step S36).

Here, in the processing of step S35 or step S36, specifically, in the roll operation with the center of gravity stationary, the actuator 120 and the actuator 130 are driven in the opposite directions at the same JOG speed. As a result, the liquid surface angle Θ roll in the roll direction can be canceled. Here, the JOG speed means the speed at which the cylinder is operated.

Further, in the pitch motion with the center of gravity stationary, the actuator 130 is driven at the JOG speed of control according to the liquid surface angle ΘPitch in the pitch direction, and the actuators 110 and 120 are moved in the opposite direction to the actuator 130 according to the liquid surface angle ΘPitch. It is driven at the JOG speed which is half the control.

Note that in the present embodiment, the processing by the low-pass filter 320 is performed after AD conversion, but the present invention is not limited to this, and low-pass processing may be performed on an analog signal.

(Load sensor control)
FIG. 10 is a flowchart showing an example of the load sensor control process of step S103.

As shown in FIG. 10, the control unit 400 detects the water level for the first time from the individual data of the load sensor 145. (Step S41).
Next, the control unit 400 detects the water level for the second time from the individual data of the load sensor 145. (Step S42).

The control unit 400 estimates the water surface angle for the first time from the data of the load sensor 145 (step S43). Next, the control unit 400 estimates the water surface angle for the second time and detects a change in the water surface angle (step S44). Specifically, the difference between the first time and the second time is 0.1 sec. Although the difference between the first time period and the second time period is 0.1 sec in the present embodiment, it is not limited to this and may be any time period such as 0.01 sec or 0.05 sec.

Here, the liquid level angle in the roll direction and the liquid level angle in the pitch direction in the load sensor control in steps S43 and S44 will be described.
The input from the load sensor 135 is defined as input Fa, the input from the load sensor 125 is defined as input Fb, and the input from the load sensor 115 is defined as input Fc.
Next, the change Θ of the liquid surface angle in the loading platform 550 is calculated from the inputs Fa, Fb, Fc for the first time and the second time. The change Δθroll in the liquid surface angle in the roll direction is represented by the following formula.

Further, the liquid surface angle ΔθPitch in the pitch direction is expressed by the following formula.

Note that Kr and Kp in the equations 5 and 6 are coefficients.
Here, in the damping control algorithm of the load sensor control according to the present embodiment, when the control amount (=control angle ΔθRoll, ΔθPitch) is calculated from the estimated water surface angle difference value (Δtan-1), The values of the combined load control coefficients Kr and Kp are adjusted in proportion to the total load value (=Fa+Fb+Fc). That is, the coefficient in the load sensor control can be set large if the total load value is large, and set small if the total load value is small.

In this case, the control amount can be optimized according to the total amount of water (water level at rest). As a result, it is possible to improve vibration damping performance without undulating.
That is, the total load value is proportional to the total amount of water (water level at rest). When the water level is high, the control amount is large, and when the water level is low, the control amount is small, and vibration is properly damped. be able to. That is, when the water depth is deep (the amount of water is large), the energy of the wave is also large, so a large amount of vibration damping energy is required, and the amount of control is increased, and when the water depth is shallow (the amount of water is small), the energy of the wave is small. Therefore, the vibration damping energy may be small, and by reducing the control amount, it is possible to suppress the occurrence of useless sloshing.

The controller 400 performs the mechanism conversion based on the change ΔΘroll of the liquid surface angle in the roll direction and the change ΔΘPitch of the liquid surface angle in the pitch direction (step S45).
Next, the control part 400 gives the control signal which carried out the mechanism conversion to the actuators 110, 120, and 130 (step S46).

Specifically, in the process of step S46, the control unit 400 controls to lower the actuator 130 and/or raise the actuators 110 and 120 when the water level of the load sensor 135 is in the rising direction.
On the other hand, the control unit 400 controls the actuator 130 to move up and/or the actuators 110 and 120 to move down when the water level of the load sensor 135 is in the descending direction.

As a merit of load sensor control, when high-order sloshing is superposed on basic-order sloshing, the wave height on the wall surface is such that high-frequency ripples are superimposed on low-frequency wave height components. , The phase relations of both are disjointed. Therefore, the wave height of the wall surface may contribute to the promotion of sloshing. On the other hand, the intention of controlling by the load applied to the container and the load exerted by the local fine wave component on the load sensor 145 of the actuators 110, 120, and 130 are integrated temporally and spatially and smoothed. That is, the same effect as applying the low-pass filter 320 is produced, and it is possible to suppress the target fundamental order sloshing.

Next, FIG. 11 is a schematic diagram showing another example of the control processing according to the present embodiment.
As shown in FIG. 11, the control unit 400 may superimpose the control amount by the acceleration control and the control amount by the load sensor control at a predetermined ratio.

Next, FIG. 12 is a schematic diagram showing still another example of the control processing according to the present embodiment.
As illustrated in FIG. 12, when the control unit 400 determines that the control angle for acceleration damping is within ±1 degree, the control unit 400 linearly accelerates as the absolute value of the control angle for acceleration damping approaches zero. The control amount by control may be reduced and the control amount by load sensor control may be increased.
In the above embodiment, the control amount is changed linearly, but the present invention is not limited to this, and the control amount may be changed in a quadratic curve or in multiple stages.

Next, FIG. 13 is a schematic diagram showing still another example of the control processing according to the present embodiment.
As shown in FIG. 13, when the acceleration damping control angle is from the + side to the zero side, the control unit 400 changes from the acceleration control to the load sensor control at +2 degrees, and the acceleration damping control angle is the zero side. From − to − side, load sensor control changes from −1 degree to acceleration control, and when the control angle of acceleration damping is from − side to zero side, −2 degree changes from acceleration control to load sensor control. When the control angle of acceleration damping is from zero side to + side, the load sensor control may be changed to the acceleration control by +1 degree.
As a result, the control unit 400 can perform hysteresis control.

(Second embodiment)
Next, FIG. 14 is a schematic diagram showing an example in which the active vibration damping device 100 according to the second embodiment is applied to a liquid tank 800. The active vibration damping device 100 according to the second embodiment will be described only on the points different from the active vibration damping device 100 according to the first embodiment.

The active vibration damping device 100 according to the second embodiment is provided between a support member 810 that connects the liquid tank 800 and the ground G.
Subsequently, in the active vibration damping device 100 according to the second embodiment, the water surface angle between the pitch and the roll is estimated as the control process of step S3 shown in FIG. 4, and the control angle is ±2 degrees or less. If it is within the range, load sensor control is performed, and if the control angle exceeds ±2 degrees, acceleration control is performed.
As a result, the sloshing phenomenon of the liquid surface in the liquid tank 800 can be suppressed.

As described above, in the active vibration damping device 100 according to the present embodiment, control can be performed by combining acceleration control and load sensor control. As a result, it is possible to reliably suppress the main swing of the cargo bed 550 of the automobile 500.
Further, the present inventor has found that the water level change of the liquid can be detected from the data of the load sensor 145. As a result, the actuators 110, 120, and 130 can be driven based on the change in the data of the load sensor 145, the main swing can be damped, and the water level change can be suppressed.

A camera or the like may be provided separately from the load sensor 145. As a result, the behavior of the luggage carrier 550 can be detected more reliably.
Furthermore, the active vibration damping device 100 according to the present invention can be applied to vibration damping or seismic isolation devices in the field of disaster prevention.

Note that, as shown in FIG. 1, the active vibration damping device 100 is fixed to the luggage carrier 550 of the automobile 500, but the invention is not limited to this, and the active vibration damping device 100 may be fixed to a wheel or a frame of a moving body having an endless track. May be installed.
Further, as shown in FIG. 2, the active vibration damping device 100 has the acceleration sensor 300 provided at the center of gravity Ag of the isosceles triangles Aa, Ab, Ac on the lower surface of the loading platform 550. It may be provided at the position of the center of gravity of an isosceles triangle to detect acceleration and control.

In the present invention, the automobile 500 corresponds to a “moving body”, the water tank corresponds to an “object”, the liquid in the water tank corresponds to a “liquid”, the actuator 140 corresponds to an “actuator”, and active vibration damping is performed. The device 100 corresponds to an “active vibration damping device”, the acceleration sensor 300 corresponds to an “acceleration detection unit, an acceleration detection process”, the low-pass filter 320 corresponds to a “filter unit, a filter process”, and the control unit 400 corresponds to “an”. The control unit", the loading platform 550 corresponds to the "packing platform", the vertices Aa, Ab, and Ac correspond to the "polygonal vertex positions", the setting unit 310 corresponds to the "setting unit", and the load sensor 145. Corresponds to the “behavior detection unit”, the setting unit 310 corresponds to the “estimation unit”, the load sensor 145 corresponds to the “load sensor”, and the flowcharts of FIGS. 5, 6, 7, 7, and 10. Corresponds to the “control step”, and the flowcharts of FIGS. 5, 6, 7, 9, and 10 correspond to the “control method of the active vibration damping device”.

Although the preferred embodiment of the present invention is as described above, the present invention is not limited thereto. It will be appreciated that various other embodiments may be made without departing from the spirit and scope of the invention. Furthermore, in the present embodiment, the actions and effects of the configuration of the present invention are described, but these actions and effects are merely examples and do not limit the present invention.

100 Active Vibration Control Device 140 Actuator 145 Load Sensor 300 Acceleration Sensor 310 Setting Unit 320 Low Pass Filter 400 Control Unit 500 Automobile 550 Cargo Bed Aa, Ab, Ac Apex

Claims (8)

An active vibration damping device for damping the vibration applied to a liquid by an actuator,
A loading platform on which the liquid is placed,
The actuators respectively arranged at the apex positions of the polygons of the lower part of the cargo bed surrounding the center of gravity of the cargo bed,
A load sensor for detecting a load applied to the actuator,
A control unit that controls the actuator based on data from the load sensor,
The active damping device, wherein the control unit detects a water level change of the liquid by the load sensor and performs load sensor control for suppressing the water level change. The control unit operates the actuator in a descending direction when the water level change of the liquid in the cargo bed in the upper side of the one actuator and the load sensor is in an upward direction, and the one actuator and the load sensor The active vibration damping device according to claim 1, wherein the actuator is operated in an ascending direction to perform load sensor control when a change in the water level of the liquid in the upper portion of the cargo bed tends to decrease. An acceleration detection unit that detects the acceleration applied to the liquid,
A filter unit that cuts frequency components of the acceleration detected by the acceleration detection unit that is more than twice the natural frequency of the object;
The control unit controls acceleration of the actuator such that the direction of acceleration of the frequency component passing through the filter unit is perpendicular to the liquid surface of the liquid , and a load that suppresses a water level change by the load sensor. The active vibration damping device according to claim 1, which performs sensor control. The control unit performs the acceleration control when the control angle of acceleration damping exceeds a predetermined value, and performs the load sensor control when the control angle of acceleration damping is equal to or less than a predetermined value. 3. The active vibration damping device described in 3. The active vibration damping device according to claim 3, wherein the control unit changes a control amount of the acceleration control and a control amount of the load sensor control within a predetermined range of acceleration. The control unit performs hysteresis control by changing the control amount when the acceleration changes from a predetermined value on the positive side to zero and when the acceleration changes from a predetermined value on the negative side to zero within the predetermined range. The active vibration damping device according to claim 4 or 5. The active vibration damping device according to claim 3, wherein the control unit superimposes a control amount of the acceleration control and a control amount of the load sensor control at a constant ratio. A control method for an active vibration damping device, wherein a vibration applied to a liquid in a platform is damped by an actuator,
An actuator step of moving by the actuators respectively arranged at the apex positions of the polygons of the lower part of the cargo bed surrounding the center of gravity of the cargo bed;
A load sensor step of detecting a load applied to the actuator,
A control step of controlling the actuator of the actuator step based on data from the load sensor step,
The control method of the active vibration damping device, wherein the control step carries out a load sensor control step of detecting a water level change of the liquid by the load sensor step and controlling the actuator so as to suppress the water level change.

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