JP7216524B2 - Cylinder displacement control system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder displacement control system, and more particularly to a cylinder displacement control system suitable for hydraulically driven cylinders used to drive mechanisms (eg, construction machinery, nuclear power robots, etc.).

As an example of a cylinder displacement control system, a technique of displacing a mechanism by a hydraulically driven actuator cylinder is known, for example, as shown in Patent Document 1 and the like.

In order to control the mechanism portion and the actuator cylinder described in Patent Document 1 so as to achieve a desired displacement, the displacement of the mechanism portion and the actuator cylinder is observed, and driving fluid is supplied until the desired displacement is achieved. and so on.

JP 2011-127596 A

However, the above-described control method using the hydraulically driven actuator cylinder may cause problems such as when a displacement sensor cannot be placed in the mechanism part or the actuator cylinder due to a severe operating environment, or when the placed displacement sensor fails. If the displacement of the cylinder cannot be observed, displacement control may become impossible.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a cylinder capable of accurately controlling the displacement of an actuator cylinder that is hydraulically driven even if the displacement of the actuator cylinder cannot be observed. An object of the present invention is to provide a displacement control system.

In order to achieve the above object, a cylinder displacement control system of the present invention comprises a cylinder and a piston arranged in the cylinder, an actuator cylinder driven by a driving fluid, and the cylinder or the piston of the actuator cylinder a control device for controlling the displacement of the actuator cylinder accompanying movement; a pipe for supplying the driving liquid to the actuator cylinder so as to match the control of the control device; the pipe and/or the driving liquid; a pipe observer for observing at least one state of the environment surrounding the pipe;
The control device controls the amount of driving liquid supplied to the pipe based on the displacement command of the actuator cylinder and the observation result of the pipe observer. It is characterized in that the diameter of the pipe is observed, and the volume change of the pipe is calculated and output from the diameter of the pipe .

According to the present invention, even if the displacement of the hydraulically driven actuator cylinder cannot be observed, the displacement of the actuator cylinder can be accurately controlled.

1 is a schematic configuration diagram showing Embodiment 1 of a cylinder displacement control system of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the control system of the amount of piping supply liquid employ|adopted for Example 1 of the cylinder displacement control system of this invention. FIG. 4 is a diagram showing another example of a control system for pipe supply fluid amount employed in the first embodiment of the cylinder displacement control system of the present invention; FIG. 5 is a characteristic diagram showing an example of the effects of the first embodiment of the cylinder displacement control system of the present invention, when the cylinder displacement is controlled without compensating for changes in pipe volume. FIG. 10 is a characteristic diagram showing an example of the effects of the first embodiment of the cylinder displacement control system of the present invention, when the cylinder displacement is controlled by compensating for changes in pipe volume. FIG. 2 is a schematic configuration diagram showing a second embodiment of the cylinder displacement control system of the present invention;

The cylinder displacement control system of the present invention will be described below based on the illustrated embodiments. The same symbols are used for the same components in each figure.

FIG. 1 is a diagram showing the configuration of Embodiment 1 of the cylinder displacement control system of the present invention.

In FIG. 1, the cylinder displacement control system 100 of this embodiment includes an actuator cylinder 130 driven by a driving fluid, a control device 110 for controlling the amount of fluid supplied to a pipe, a pipe 120 through which the driving fluid flows, and the outer diameter of the pipe 120. and a pipe observer 140 such as a hydraulic pressure gauge for measuring the hydraulic pressure in the pipe 120 .

The actuator cylinder 130 consists of a cylinder 131 and a piston 132, the cylinder 131 being divided by the piston 132 into two chambers, an extension chamber 131a and a retraction chamber 131b.

In the example of FIG. 1, the drive fluid is supplied from the pipe 120 to the extension chamber 131a, so that the cylinder displacement X, which is the distance between the end 131c of the cylinder 131 and the head 132a of the piston 132, increases. As the liquid is discharged from the expansion chamber 131a to the pipe 120, the cylinder displacement X is reduced. The piston 132 is connected to construction machinery, nuclear power robots, and the like.

The pipe 120 supplies the driving liquid to the actuator cylinder 130 so as to match the control of the control device 110, and the pipe observer 140 measures the outer diameter of the pipe 120 with the displacement gauge described above, thereby measuring the displacement of the pipe 120. The expansion/contraction is observed, and the pipe volume change ΔV due to this expansion/contraction is calculated and output (the pipe observer 140 has a calculation function).

The control device 110 supplies the pipe supply fluid amount Qr to the pipe 120 so that the cylinder displacement X is the cylinder displacement command Xr based on the cylinder displacement command Xr and the pipe volume change ΔV from the host controller (not shown).

Here, in the example of FIG. 1, the drive fluid is supplied only to the extension chamber 131a in the actuator cylinder 130, but the configuration of the present invention is not limited to that. For example, the drive liquid may be configured to be supplied only to the contraction chamber 131b. At this time, when the driving fluid is supplied to the contraction chamber 131b, the cylinder displacement X decreases, and when it is discharged, X increases. Moreover, the driving liquid may be supplied to both the extension chamber 131a and the contraction chamber 131b.

Also, a plurality of pipe observers 140 may be arranged with respect to the pipe 120 . By observing the pipe volume change dV at a plurality of points on the pipe 120, the pipe volume change ΔV can be estimated with high accuracy, enabling more accurate cylinder displacement control.

Next, means for obtaining the pipe supply liquid amount Qr will be described using mathematical expressions.

In the example of FIG. 1, when the effective cross-sectional area of the extension chamber 131a is A, the volume Qa of the driving fluid filled in the extension chamber 131a when the cylinder is displaced X is given by Equation (1).

Therefore, when the pipe 120 is filled with driving fluid, if the pipe 120 does not expand or contract, the pipe supply liquid, which is the amount of driving fluid supplied to the pipe 120 by the control device 110 in order to realize the cylinder displacement X, is The quantity Qr becomes Qa.

Therefore, when the pipe 120 expands and contracts due to the hydraulic pressure and causes a pipe volume change ΔV, the pipe supply liquid amount Qr for realizing the cylinder displacement X is given by Equation (2).

The cylinder displacement control system 100 of this embodiment controls the cylinder displacement X to be the cylinder displacement command Xr. Therefore, the control device 110 calculates the pipe supply liquid amount Qr based on the cylinder displacement command Xr and the pipe volume change ΔV, for example, as shown in Equation 3, and supplies the pipe 120 with the pipe supply liquid amount Qr as the driving liquid. supply.

FIG. 2 shows an example of a system for controlling the supply of the pipe supply liquid amount Qr in the controller 110 (the system in FIG. 2 is incorporated in the controller 110 in FIG. 1). In FIG. 2, only the system for applying positive pressure to the actuator cylinder 130 is shown.

In FIG. 2, pump 114 supplies the driving liquid in tank 115 to pipe 120 in accordance with the degree of opening of valve 113 . The valve controller 111 time-integrates the driving liquid flow rate observed by the flowmeter 112 to calculate the observed value of the pipe supply liquid amount, and controls the opening of the valve 113 so that the pipe supply liquid amount Qr becomes the command value. . As a result, the pipe 120 can be supplied with the driving liquid of the pipe supply liquid amount Qr.

FIG. 3 shows another example of a system for controlling the supply of the pipe supply liquid amount Qr in the control device 110 .

In FIG. 3, the syringe pump 116 supplies the driving liquid in the pump cylinder 1161 to the pipe 120 according to the displacement Xp of the pump piston 1162 . Here, the piston displacement Xpr that realizes the pipe supply fluid amount Qr is obtained from Equation 4 using the effective cross-sectional area Ap of the pump cylinder 1161 .

The piston displacement controller 119 drives the piston driving device 117 so that the piston displacement Xp observed by the piston displacement observer 118 becomes the command value Xpr of the piston displacement calculated from the command value of the pipe supply liquid amount Qr. Displace pump piston 1162 . As a result, the pipe 120 can be supplied with the driving liquid of the pipe supply liquid amount Qr.

The driving force with which the piston driving device 117 drives the pump piston 1162 is not limited to electromagnetic force such as an electric motor, and may be hydraulic pressure or the like.

Next, an example of means for the pipe observer 140 to observe the pipe volume change ΔV will be described.

First, as an example of the pipe observer 140, the outer diameter D of the pipe 120 is observed with a displacement gauge. Assuming that the outer diameter of the pipe 120 when no liquid pressure is applied to the pipe 120 is D0, and the wall thickness δ of the pipe 120 does not change with the liquid pressure, the pipe volume change dV per unit length dL is number 5.

Therefore, the pipe volume change ΔV of the pipe 120 having the length L can be observed using the outer diameter D of the pipe 120 observed from Equation (6).

Furthermore, the volume of the driving liquid may change depending on the liquid temperature of the driving liquid. Piping observer 140 may observe the fluid temperature and derive the drive fluid volume change based on the increase in fluid temperature. A substantial pipe volume change .DELTA.V in consideration of the driving liquid volume change can be obtained by a method such as taking the difference in the driving liquid volume change from the pipe volume change of the single pipe. The relationship between this drive liquid volume change and the liquid temperature may be obtained experimentally, for example.

Needless to say, the pipe observer 140 can also observe the pipe volume change ΔV by observing the inner diameter (D−δ) of the pipe 120 .

As another example of the pipe observer 140, the hydraulic pressure P within the pipe 120 may be observed. In this example, when the force applied to the pipe 120 by the hydraulic pressure and the restoring force of the pipe 120 are balanced, the change in pipe volume dV per unit length dL is expressed by the following formula 7: the hydraulic pressure P and the environmental pressure (the pipe 120 is proportional to the difference from P0.

Therefore, the pipe volume change ΔV of the pipe 120 of length L can be observed using the hydraulic pressure P observed from Equation (6). It should be noted that the proportionality coefficient K of Equation 7 can be theoretically or experimentally obtained in advance according to the pipe 120 to be used.

4(a) and 4(b) are diagrams showing an example of the effects of the cylinder displacement control system of this embodiment.

FIG. 4(a) shows the case where the cylinder displacement is controlled without compensating for the pipe volume change ΔV.

As shown in FIG. 4(a), due to the expansion and contraction of the pipe 120, the cylinder displacement lags behind the cylinder displacement command and has hysteresis with respect to the displacement command.

FIG. 4B shows a case where the cylinder displacement is controlled by compensating for the pipe volume change ΔV according to the present invention.

As shown in FIG. 4B, by compensating for the pipe volume change ΔV, the cylinder displacement follows the cylinder displacement command well.

As described above, according to this embodiment, in the displacement control system for the hydraulically driven actuator cylinder 130, even if the displacement of the actuator cylinder 130 cannot be observed, the displacement of the actuator cylinder 130 can be accurately controlled.

Further, in the displacement control of the actuator including the mechanism section driven by the actuator cylinder 130, by controlling the displacement of the actuator cylinder 130 using the cylinder displacement control system 100 of the present embodiment, the displacement of the actuator including the mechanism section can be controlled. Displacement can be precisely controlled.

FIG. 5 is a diagram showing the configuration of Embodiment 2 of the cylinder displacement control system of the present invention.

In FIG. 5, the cylinder displacement control system 100 is composed of an actuator cylinder 130 driven by a driving liquid, a control device 110 for controlling the amount of liquid supplied to the piping, a piping 120 through which the driving liquid flows, and a piping observation device 140 to be described later. It is configured.

The actuator cylinder 130 consists of a cylinder 131 and a piston 132. The piston 132 divides the cylinder 131 into two chambers, an extension chamber 131a and a retraction chamber 131b.

In the example of FIG. 5, the drive fluid is supplied from the pipe 120 to the expansion chamber 131a, so that the cylinder displacement X, which is the distance between the end 131c of the cylinder 131 and the head 132a of the piston 132, increases. As the liquid is discharged from the expansion chamber 131a to the pipe 120, the cylinder displacement X is reduced. The piston 132 is connected to construction machinery, nuclear power robots, and the like.

Piping 120 supplies drive fluid to actuator cylinder 130 to match the control of controller 110 .

The piping condition observer 140 consists of a piping condition observer 141 and an environmental condition observer 142, and the conditions of the pipe 120 and the driving liquid observed by the pipe condition observer 141 (the outer diameter of the pipe 120, the inner diameter of the pipe 120, the inner diameter of the pipe 120, and the The pressure, liquid temperature, composition, etc. of the driving liquid) and the conditions of the surrounding environment observed by the environmental condition observation device 142 (the pressure, temperature, humidity, etc. of the surrounding environment described later, the lightness that causes hardening of the piping material, etc. UV intensity, radiation intensity, atmosphere components, etc.), the pipe volume change ΔV is calculated and output.

Based on the cylinder displacement command Xr and the pipe volume change ΔV, the control device 110 supplies the pipe supply liquid amount Qr to the pipe 120 so that the cylinder displacement X is the displacement command Xr.

Next, an example of a method for observing the pipe volume change ΔV by the pipe observer 140 will be described.

The pipe condition observer 141 observes, for example, one or more physical quantities among the outer diameter of the pipe 120, the inner diameter of the pipe 120, the liquid pressure, the liquid temperature, and the components of the driving liquid. On the other hand, the environmental condition observer 142 detects, for example, the pressure, temperature, humidity, etc. of the surrounding environment, such as brightness, ultraviolet intensity, radiation intensity, atmospheric components (air components around the pipe 120), etc., which are factors such as hardening of pipe materials. Observe one or more physical quantities among

For example, when calculating the pipe volume change dV in the unit length dL using Equation 7 above, based on the hydraulic pressure P observed by the pipe condition observer 141 and the pressure P0 observed by the environmental condition observer 142 , the pipe volume change dV can be observed. By observing and using the pressure P0 with the environmental condition observation device 142, it is possible to observe the pipe volume change ΔV with high accuracy even in environments such as driving in water, which are greatly different from the atmospheric pressure.

Furthermore, the volume of the driving liquid may change depending on the components of the driving liquid, the liquid temperature, and the like. From the pipe volume change of the single pipe, it is possible to obtain the actual pipe volume change ΔV considering the volume change of the driving liquid by a method such as taking the difference of the volume change of the driving liquid. By obtaining the change experimentally, for example, the pipe volume change ΔV can be observed with high accuracy.

In addition, since the proportional coefficient K in Equation 7 above is a coefficient representing the ease of deformation of the pipe 120, depending on the material of the pipe 120, the deformation may occur depending on conditions such as the temperature of the driving liquid and the temperature of the surrounding environment. Ease can vary.

Therefore, by experimentally obtaining the proportional coefficient K under these conditions in advance, the pipe volume change ΔV can be observed with high accuracy even in various environments.

A plurality of pipe observers 140 may be arranged on the pipe 120 . Also, one pipe observer 140 may be composed of a plurality of pipe condition observers 141 and environmental condition observers 142, respectively.

By observing conditions at a plurality of locations in the pipe 120 and at a plurality of locations in the environment, the pipe volume change ΔV can be estimated with high accuracy, and more accurate cylinder displacement control becomes possible.

As described above, according to this embodiment, in the displacement control system for the hydraulically driven actuator cylinder, the displacement of the actuator cylinder can be accurately controlled even when the displacement of the actuator cylinder cannot be observed.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

DESCRIPTION OF SYMBOLS 100... Cylinder displacement control system, 110... Control device, 111... Valve controller, 112... Flow meter, 113... Valve, 114... Pump, 115... Tank, 116... Syringe pump, 1161... Pump cylinder, 1162... Pump piston, 117... Piston drive device, 118... Piston displacement observer, 119... Piston displacement controller, 120... Piping, 130... Actuator cylinder, 131... Cylinder, 131a... Extension chamber, 131b... Contraction chamber, 131c... End of cylinder, 132...Piston, 132a...Head of piston, 140...Pipe observer, 141...Pipe condition observer, 142...Environmental condition observer.

Claims (8)

an actuator cylinder composed of a cylinder and a piston disposed within the cylinder and driven by a driving fluid;
a control device for controlling displacement of the actuator cylinder accompanying movement of the cylinder or the piston of the actuator cylinder;
a pipe for supplying the driving liquid to the actuator cylinder so as to match the control of the control device;
a pipe observer for observing at least one state of the pipe and/or the driving liquid and the surrounding environment of the pipe;
The control device controls an amount of driving liquid supplied to the pipe based on a displacement command of the actuator cylinder and an observation result of the pipe observer ,
The cylinder displacement control system , wherein the pipe observer observes the diameter of the pipe, calculates and outputs a pipe volume change from the diameter of the pipe . The cylinder displacement control system according to claim 1 ,
The control device calculates the pipe supply liquid amount based on the pipe volume change calculated and output by the pipe observation device and the cylinder displacement command from the host controller, and uses this pipe supply liquid amount as the driving liquid. A cylinder displacement control system, characterized by supplying to the piping. In the cylinder displacement control system according to claim 2 ,
The driving liquid to the pipe is supplied by a pump installed on the pipe and connected to a tank storing the driving liquid,
The pump supplies the driving liquid in the tank to the pipe according to the degree of opening of a valve installed in the pipe,
The flow rate of the driving liquid observed by the flow meter installed in the pipe is integrated over time to calculate the observed value of the pipe supply liquid amount, and the opening of the valve is adjusted so that the pipe supply liquid amount becomes the command value. A cylinder displacement control system comprising a controlling valve controller. In the cylinder displacement control system according to claim 2 ,
A syringe pump comprising a pump cylinder and a pump piston is provided on the pipe,
The syringe pump supplies the driving liquid in the pump cylinder to the pipe according to the displacement of the pump piston,
A piston driving device is driven so that the displacement of the pump piston observed by a piston displacement observer that observes the displacement of the pump piston becomes the command value of the displacement of the pump piston calculated from the command value of the amount of liquid supplied to the pipe. A cylinder displacement control system, comprising: a piston displacement controller for displacing the pump piston by an actuator cylinder composed of a cylinder and a piston disposed within the cylinder and driven by a driving fluid;
a control device for controlling displacement of the actuator cylinder accompanying movement of the cylinder or the piston of the actuator cylinder;
a pipe for supplying the driving liquid to the actuator cylinder so as to match the control of the control device;
a pipe observer for observing at least one state of the pipe and/or the driving liquid and the surrounding environment of the pipe;
The control device controls an amount of driving liquid supplied to the pipe based on a displacement command of the actuator cylinder and an observation result of the pipe observer,
The pipe condition observer is composed of a pipe condition observer and an environmental condition observer. A cylinder displacement control system, wherein a change in volume is calculated and output, and the output result is transmitted to the control device. In the cylinder displacement control system according to claim 5 ,
The piping condition observer observes and outputs at least one of the diameter of the piping, the pressure of the driving liquid, the temperature of the driving liquid, and the components of the driving liquid,
The environmental condition observer observes and outputs at least one of environmental pressure, environmental temperature, environmental humidity, environmental brightness, environmental ultraviolet intensity, environmental radiation intensity, and atmospheric components. system. In the cylinder displacement control system according to claim 5 or 6 ,
The control device calculates the pipe supply liquid amount based on the pipe volume change calculated and output by the pipe observation device and the cylinder displacement command from the host controller, and uses this pipe supply liquid amount as the driving liquid. A cylinder displacement control system, characterized by supplying to the piping. In the cylinder displacement control system according to any one of claims 1 to 7 ,
A cylinder displacement control system, wherein a plurality of the pipe observation devices are installed on the pipe.

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