JP5245085B2 - Vibration suppression control input determination method for time deformation system, conveyance system, and vibration suppression control input calculation program for time deformation system - Google Patents

Description

The present invention relates to a vibration suppression control input determination method for a time deformation system, a conveyance system, and a vibration suppression control input calculation program for the time deformation system, and in particular, a vibration suppression control input determination method for a time deformation system capable of obtaining a high vibration suppression effect, The present invention relates to a vibration suppression control input calculation program for a transport system and a time deformation system.

In factories and the like, transport systems such as cranes, gantry loaders, and robot arms are used. These transfer systems are required to have high speed in order to improve production efficiency.

FIG. 16 is a diagram schematically illustrating an example of a conventional transport system. This transport system includes a rail 100, a carriage 101 that travels on the rail 100, and an arm 102, and is a system that suspends and transports the article 103 to be transported by the arm 102. In this transport system, when the carriage 101 is driven at high speed without performing vibration suppression control, a large vibration is generated in the conveyed object 103 when the carriage 101 is accelerated or decelerated. If the conveyed object 103 vibrates greatly when the carriage 101 is traveling, it is dangerous for surrounding workers. Moreover, in order to move to the next process in a short time after stopping, it is desirable that the residual vibration of the conveyed object 103 is as small as possible. In a transport system, speeding up and vibration are contradictory problems, but various control methods have been proposed for realizing speeding up and vibration suppression at the same time.

With reference to FIG. 17, the anti-phase input control (Preshaping control) which is an example of vibration suppression control is demonstrated. FIG. 17A is a graph showing the input acceleration input to the motor in the conventional antiphase input control, and FIG. 17B shows the damping effect obtained as a result of applying the input acceleration to the motor. It is a graph to show.

As shown in FIG. 17A, it is assumed that the first input a ₁ is added at time t ₁ . Due to the first input a _1, it occurs vibration as shown by the solid line in FIG. 17 (b). Then, the time _{t 2} is later half period of oscillation, as shown in FIG. 17 (a), adding a second input _{a 2.} Then, due to the second input a ₂ , vibration as shown by a broken line in FIG. If the vibration caused by the second input a ₂ has the same amplitude as the vibration caused by the first input a ₁ and has the opposite phase, the vibration caused by the first input a ₁ ; second due to input a ₂ vibration and cancel each other, as shown by a chain line in FIG. 17 (b), the vibration can be suppressed.

The first input a ₁ and the second input a ₂ and the times t ₁ and t ₂ during which these inputs are applied can be calculated based on the natural frequency of the transport system. In the transport system as shown in FIG. 16, if the arm length L and the mass m of the load 103 are always kept constant, the natural frequency is constant, so the first input a ₁ , the second input a ₂ , The times t ₁ and t ₂ can be obtained by a known formula, and the control input can be easily shaped.

U.S. Pat. No. 4,916,635 US Pat. No. 6,102,221

However, the conventional antiphase input control has the following problems. First, the conventional anti-phase input control provides a high damping effect for a system with a constant natural frequency, but a sufficient effect for a system with a varying natural frequency. The problem is that it is not possible. For example, when the arm length L is constant and the load 103 is moved only in the lateral direction, the natural frequency is constant, so that a high vibration damping effect can be obtained by the conventional antiphase input control.

On the other hand, when the load 103 is moved in the horizontal direction and the arm length L is also changed at the same time, that is, when the arm length L is changed during the movement in the horizontal direction, the change in the arm length L is accompanied. The natural frequency fluctuates and becomes a problem.

FIG. 18 is a graph showing the relationship between the arm length L and the natural frequency ω in the transport system shown in FIG. As shown in FIG. 18, the natural frequency ω has a lower frequency as the arm length L becomes longer.

Therefore, in the anti-phase input control in which the control input is determined on the assumption that the natural frequency ω is constant, the fluctuation of the natural frequency ω during the conveyance cannot be dealt with, and a sufficient damping effect cannot be obtained. Also, when the object to be transported is liquid, the natural frequency fluctuates with the fluctuation of the liquid level when the liquid level changes during transportation. Therefore, a problem similar to the case where the arm length is changed occurs.

As a second problem, the conventional anti-phase input control can suitably suppress the vibration in the first-order mode but cannot cope with the vibration in the higher-order mode. In particular, in recent transport systems, the weight of the transport arm and the like is reduced in order to increase the speed and reduce the operating energy. If a low-rigidity material is used for weight reduction and the structure becomes flexible, high-order mode vibrations are likely to occur, and the conventional antiphase input control cannot provide a sufficient damping effect.

Therefore, in various transport industries, there is a demand for a control method that can suitably suppress vibration in a transport system in which such fluctuations in the natural frequency occur or a transport system in which higher-order mode vibration can occur.

The present invention has been made to solve the above-described problems, and a vibration suppression control input determination method for a time deformation system capable of obtaining a high vibration suppression effect, a conveyance system, and a vibration suppression control input for a time deformation system. The purpose is to provide an arithmetic program.

The vibration suppression control input determination method for the time-deformation system according to claim 1 is the mass, liquid level of the object to be conveyed held by the conveyance body or the conveyance body and the conveyance object while the conveyance body is moved by the driving device. A vibration suppression control input determination method for a deformation system for determining a vibration suppression control input to be applied to the drive device in order to suppress vibration when changing the length of an arm interposed between objects, The deformation system frequency acquisition step for acquiring the correspondence between the variation in the mass, liquid level or arm length of the transferred object and the natural frequency, and the mass, liquid level and arm of the transferred object are Based on the natural frequency when the carrier is moved by the driving device with the arm length being constant when intervening, a reference vibration suppression input for suppressing the vibration of the natural frequency is acquired. The reference vibration suppression input acquisition step, and the reference vibration suppression input acquired by the reference vibration suppression input acquisition step, the mass, liquid level, or arm of the conveyed object acquired by the time deformation system frequency acquisition step. In the vibration suppression control input determination method for the time deformation system described above, comprising a vibration suppression control input determination step for determining a vibration suppression control input that reflects the correspondence between the fluctuation in length and the natural frequency. The vibration suppression control input determination step includes a vibration suppression control input determination step for a time-deformation system characterized by determining a vibration suppression control input based on u (t) of the following formula (1): To do.
However, uV: reference vibration suppression input XV: the mass, liquid level of the object to be conveyed, and the arm length when the arm is interposed, and the reference vibration suppression input uV of the object to be conveyed when the reference vibration suppression input uV is input to the driving device. vibration
k i (t) is the process gain of the i-th mode at time t, and ω i (t) is the natural frequency of the i-th mode at time t.

The vibration suppression control input determination method for the time deformation system according to claim 2 is the vibration suppression control input determination method for the time deformation system according to claim 1, wherein a predetermined test input is input to the driving device, During the movement, a test process for changing the mass, liquid level, or arm length of the conveyed object, and the test process measures vibrations of the conveyed object during the movement of the conveyed object. From the relationship between the vibration measurement process, the test input input in the test process, and the vibration measured in the vibration measurement process, the mass of the transported object, the liquid level, and the length of the arm when the arm is interposed A parameter identification step for identifying a reference natural frequency that is a natural frequency when the thickness is constant, and the reference vibration suppression input acquisition step includes the same parameter. Based on the reference natural frequency identified by step, and acquires the reference vibration suppression input.

The vibration suppression control input determination method for the time deformation system according to claim 3 is the vibration suppression control input determination method for the time deformation system according to claim 2, wherein the reference natural frequency of a plurality of modes is identified by the parameter identification step. In this case, the reference vibration suppression input acquisition step acquires a reference vibration suppression input corresponding to the plurality of modes.

The vibration suppression control input determination method for the time deformation system according to claim 4 is the vibration suppression control input determination method for the time deformation system according to claim 2 or 3, wherein the time deformation system frequency acquisition step is the test step. From the relationship between the test input input by the vibration and the vibration measured by the vibration measurement step, the correspondence between the variation in the mass, liquid level or arm length of the transferred object and the natural frequency is obtained. It is a thing to do.

The vibration suppression control input determination method for the time deformation system according to claim 5 is the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 4, wherein the test step includes: A step of changing a mass, a liquid level, or an arm length of the conveyed object while moving from the first position to the second position; It is characterized in that a correspondence relationship between a fluctuation in the mass, liquid level, or arm length of the conveyed object and the natural frequency during the movement from the first position to the second position is acquired.

The vibration suppression control input determination method for the time deformation system according to claim 6 is determined by the vibration suppression control input determination step in the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 5. The vibration suppression control input is input as a test input in the test step, and based on the test input, the time deformation system frequency acquisition step, the parameter identification step, the reference vibration suppression input acquisition step, And a repetition step of repeating the vibration suppression control input determination step.

The vibration suppression control input determination method for the time deformation system according to claim 7 is obtained by the reference vibration suppression input acquisition step in the vibration suppression control input determination method for the time deformation system according to any one of claims 1 to 6. The reference vibration suppression input includes at least one input and one or more inputs that generate vibrations having a phase opposite to that of the vibration caused by the input.

According to an eighth aspect of the present invention, there is provided a transfer system for storing the vibration suppression control input determined by the method according to any one of the first to seventh aspects, and driving for receiving the vibration suppression control input stored in the storage means. The apparatus includes a device and a transport body that is driven by the driving device and holds an object to be transported.

The transport system according to claim 9 is the transport system according to claim 8 , wherein the transport body is driven in the horizontal direction by the driving device and suspends the transported object via an arm. Arm length changing means for changing the length of the arm interposed between the transfer body and the transfer object is provided.

The transport system according to claim 10 , wherein a transport body that holds a transported object, a drive device that moves the transport body, and a transport target that is held by the transport body while the transport body is moved by the drive device. Vibration suppression that determines the vibration suppression control input to be applied to the drive device in order to suppress vibration when the mass, liquid level of the object, or the length of the arm interposed between the transport body and the transported object is varied. A control input determination means, and a time-deformation system frequency acquisition means for acquiring a correspondence relationship between a variation in the mass, liquid level, or arm length of the conveyed object and the natural frequency; Based on the natural frequency when the transport device is moved by the driving device with the arm length being constant when the mass of the object to be conveyed, the liquid level, and the arm are interposed, the vibration of the natural frequency To suppress Reference vibration suppression input acquisition means for acquiring a reference vibration suppression input, and the vibration suppression control input determination means acquires the time-deformation system frequency in the reference vibration suppression input acquired by the reference vibration suppression input acquisition means. In the vibration suppression control input determination method for the time-deformation system described above , reflecting the correspondence relationship between the natural frequency and the variation in the mass, liquid level, or arm length of the conveyed object acquired by the means , The vibration suppression control input determination step determines the vibration suppression control input for the deformation system when determining the vibration suppression control input based on u (t) in the equation (1).

In addition, each process of Claims 2-7 may be provided in the conveyance system of this Claim 10 as a means.

The vibration suppression control input calculation program for the time deformation system according to claim 11 is the mass, liquid level, or the transport body and the transported body of the transported object held by the transporting body while the transporting body is moved by the driving device. A program for causing a computer to calculate a vibration suppression control input to be applied to the drive device in order to suppress vibration when the length of an arm interposed between the object and the object is varied, The deformation system frequency acquisition step when acquiring the correspondence between the fluctuation of the liquid level or the length of the arm and the natural frequency, and the mass of the transported object, the liquid level, and the arm when the arm is interposed A reference for obtaining a reference vibration suppression input for suppressing vibration of the natural frequency based on the natural frequency when the transport device is moved by the driving device with a constant length. In the dynamic suppression input acquisition step, and the reference vibration suppression input, the variation in the mass, liquid level, or arm length of the conveyed object acquired in the time deformation system frequency acquisition step, and the natural frequency The vibration for calculating the vibration suppression control input for the time-deformation system is characterized in that the vibration suppression control input determination step reflects the correspondence relationship, and the vibration suppression control input based on u (t) in the equation (1) is determined. A suppression control input calculation step is a program that causes a computer to calculate.

Incidentally, the vibration suppression control input calculation program to deformation system when this claim 11, wherein, as step the steps according to claims 2 7, or may be executed by a computer.

According to the vibration suppression control input determination method for the time deformation system according to claim 1, the time deformation system frequency acquisition step, the variation in the mass, liquid level, or arm length of the conveyed object, the natural frequency, Is obtained. Based on the natural vibration frequency in the case where the carrier is moved by the drive device with the reference vibration suppression input acquisition step, the mass of the conveyed object, the liquid level, and the arm length is constant when the arm is interposed. The reference vibration suppression input for suppressing the vibration of the natural frequency is acquired. Then, in the reference vibration suppression input acquired by the reference vibration suppression input acquisition step, the variation of the mass, liquid level, or arm length of the conveyed object acquired by the time deformation system frequency acquisition step and the inherent The vibration suppression control input that reflects the correspondence with the frequency is determined by the vibration suppression control input determination step.
At this time, the vibration suppression control input determination step includes a vibration suppression control input determination step for the time-deformation system, wherein the vibration suppression control input is determined based on u (t) of the equation (1). It is characterized by.

Therefore, it is possible to determine the vibration suppression control input that takes into account fluctuations in the natural frequency accompanying fluctuations in the mass, liquid level, or arm length of the transferred object, and the vibration suppression control input is input to the drive device. By doing so, there is an effect that a high vibration damping effect can be obtained regardless of variations in the mass, liquid level, or arm length of the conveyed object. Moreover, in this invention, it is a control type which considered even the higher order mode so that it may exist in the vector notation of several 3 and several 4. For this reason, there is an effect that there is little residual vibration.

Note that the time deformation system frequency acquisition step acquires the correspondence between any one of the mass, liquid level, or arm length of the conveyed object and the natural frequency. Alternatively, a correspondence relationship between two or more fluctuations and the natural frequency may be acquired.

According to the vibration suppression control input determination method for the time deformation system according to claim 2, the vibration suppression control input determination method for the time deformation system according to claim 1 operates in the same manner, and a predetermined amount is applied to the drive device by the test process. While the test input is input and the transport body is moved, the mass of the transported object, the liquid level, or the length of the arm is changed. And the vibration of a to-be-conveyed object is measured while moving a conveyance body by the test process. And, from the relationship between the test input input by the test process and the vibration measured by the vibration measurement process, when the arm length is constant when the mass of the transported object, the liquid level, and the arm are interposed The reference natural frequency which is the natural frequency of is identified by the parameter identification step. Then, a reference vibration suppression input is acquired based on the reference natural frequency identified by the parameter identification step.

Therefore, according to the vibration suppression control input determination method for the time deformation system according to claim 2, in addition to the effect exhibited by the vibration suppression control input determination method for the time deformation system according to claim 1, the vibration model is unknown. The vibration suppression control input can be easily determined.

According to the vibration suppression control input determination method for the time deformation system according to claim 3, in addition to the effect of the vibration suppression control input determination method for the time deformation system according to claim 2, a plurality of mode references are obtained by the parameter identification step. When the natural frequency is identified, the reference vibration suppression input acquisition step acquires a reference vibration suppression input corresponding to a plurality of modes, so that it is possible to determine a vibration suppression control input corresponding to vibration including a higher order mode. it can. Therefore, there is an effect that it is possible to sufficiently control the vibration of the higher mode generated in the transport system. As a result, the conveyance system can be made of a low-rigidity material to reduce the weight, and an effect of saving operating energy can be obtained.

According to the vibration suppression control input determination method for the time deformation system according to claim 4, the vibration suppression control input determination method for the time deformation system according to claim 2 or 3 operates in the same manner and is input by a test process. From the relationship between the test input and the vibration measured in the vibration measuring step, the correspondence between the variation in the mass, liquid level, or arm length of the transferred object and the natural frequency is acquired.

Therefore, according to the vibration suppression control input determination method for the time deformation system according to claim 4, in addition to the effect of the vibration suppression control input determination method for the time deformation system according to claim 2, the number of steps is reduced. There is an effect that is easy.

According to the vibration suppression control input determination method for the time deformation system according to claim 5, the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 4 operates in the same manner, and the conveyed object The correspondence between the variation in the mass, liquid level, or arm length of the transferred object and the natural frequency during the movement from the first position to the second position is acquired.

Therefore, according to the vibration suppression control input determination method for the time deformation system according to claim 5, in addition to the effect exhibited by the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 4, the vibration suppression control input determination method is predetermined. In batch-type conveyance in which conveyance from the first position to the second position is repeatedly performed, a high vibration damping effect can be obtained.

According to the vibration suppression control input determination method for the time deformation system according to claim 6, the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 5 operates in the same manner as the vibration suppression control input determination method. The vibration suppression control input determined by the input determination step is input as a test input in the test step, and based on the test input, a time deformation system frequency acquisition step, a parameter identification step, a reference vibration suppression input acquisition step, The vibration suppression control input determination step is repeated. Here, since a vibration suppression control input is input as a test input, in the parameter identification process, a more accurate reference natural frequency can be identified in the frequency band possessed by the vibration suppression control input. A reference vibration suppression input can be acquired based on an accurate reference natural frequency. As a result, it is possible to determine a vibration suppression control input with higher accuracy than when an input including all frequencies is added.

Therefore, according to the vibration suppression control input determination method for the time deformation system according to claim 6, in addition to the effect of the vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 5, higher There is an effect that it is possible to determine a vibration suppression control input that provides a vibration suppression effect.

According to the vibration suppression control input determination method for the time deformation system according to claim 7, in addition to the effect of the vibration suppression control input determination method for the time deformation system according to claim 1, the reference vibration suppression input Since the reference vibration suppression input acquired by the acquisition step includes at least one input and one or more inputs that generate vibrations having the opposite phase to the vibration caused by the input, the reference vibration suppression input is simply calculated. There is an effect that can be shaped by.

According to the transport system of claim 8, the vibration suppression control input determined by the method of any one of claims 1 to 7 is input to the drive device, and the transport device that holds the object to be transported by the drive device. Since it is driven, there is an effect that a high damping effect can be obtained. As a result, residual vibration is suppressed even in high-speed conveyance, and the production tact time can be shortened.

According to the transport system of the ninth aspect , in addition to the effect produced by the transport system according to the eighth aspect , the transport body is driven in the horizontal direction by the driving device, and the object to be transported is suspended via the arm. In the transfer system provided with the arm length changing means for changing the length of the arm interposed between the transfer body and the transferred object, there is an effect that a high damping effect can be obtained.

According to the transport system of the tenth aspect , the time deformation system frequency acquisition means acquires the correspondence between the variation in the mass, liquid level, or arm length of the transported object and the natural frequency, and In order to suppress the vibration of the natural frequency based on the natural frequency when moving the conveyance body by the driving device with the arm length being constant when the mass, liquid level and arm of the conveyed object are interposed The reference vibration suppression input is acquired by the reference vibration suppression input acquisition means. Then, the reference vibration suppression input acquired by the reference vibration suppression input acquisition means is inherent to the variation in the mass, liquid level, or arm length of the conveyed object acquired by the time deformation system frequency acquisition means. A vibration suppression control input that reflects the correspondence with the frequency is determined by the vibration suppression control input determination means.

Therefore, it is possible to determine the vibration suppression control input that takes into account fluctuations in the natural frequency accompanying fluctuations in the mass, liquid level, or arm length of the transferred object, and the vibration suppression control input is input to the drive device. By doing so, there is an effect that a high vibration damping effect can be obtained regardless of variations in the mass, liquid level, or arm length of the conveyed object. As a result, residual vibration is suppressed even in high-speed conveyance, and the production tact time can be shortened.

According to the vibration suppression control input calculation program for the time deformation system according to claim 11 , the time deformation system frequency acquisition step performs a change in the mass, liquid level, or arm length of the conveyed object, and the natural frequency. When the carrier is moved by the drive unit with the arm length being constant when the arm is interposed, the inherent mass is obtained on the basis of the natural frequency. A reference vibration suppression input for suppressing the vibration of the frequency is acquired by the reference vibration suppression input acquisition step. And, in the reference vibration suppression input, the correspondence between the natural frequency and the variation of the mass of the transported object, the liquid level, or the length of the arm acquired by the time deformation system frequency acquisition step is reflected. The vibration suppression control input is calculated by the vibration suppression control input calculation step.

Therefore, it is possible to determine the vibration suppression control input that takes into account fluctuations in the natural frequency accompanying fluctuations in the mass, liquid level, or arm length of the transferred object, and the vibration suppression control input is input to the drive device. By doing so, there is an effect that a high vibration damping effect can be obtained regardless of variations in the mass, liquid level, or arm length of the conveyed object. As a result, residual vibration is suppressed even in high-speed conveyance, and the production tact time can be shortened.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a front view of a transport system 1 to which an embodiment of the present invention is applied. As shown in FIG. 1, the transport system 1 is provided with a personal computer 10 (hereinafter referred to as a PC 10) as a control device and a gantry loader 20 controlled by the PC 10.

The gantry loader 20 is provided with an installation rail 22 provided in the horizontal direction, a traveling platform 24 that travels on the installation rail 22, and an elevating rod 26 that can be raised and lowered in the vertical direction. A loader head 28 is attached. The loader head 28 is provided with two loader chucks 30 in a lateral orientation and a downward orientation. Further, an acceleration sensor 49 (see FIG. 2) for measuring the vibration of the work W is attached to either the work W gripped by the loader chuck 30 or the loader head 28.

The traveling platform 24 is driven in the horizontal direction along the installation rail 22 by an X-axis servo motor 40 (see FIG. 2), which will be described later, and suspends and conveys the workpiece W via the lifting rod 26. In the following description, the longitudinal direction of the installation rail 22 is referred to as the x direction, and the ascending / descending direction of the elevating rod 26 is referred to as the z direction. Further, the length from the upper end of the installation rail 22 to the loader chuck 30 is referred to as an arm length.

According to the gantry loader 20, first, at the first position 34, the work W on the work supply table 35 is gripped by the downward loader chuck 30, and the traveling table 24 is moved in the x direction by the X-axis direction servo motor (see FIG. 2). Move to. During the movement in the x direction, the elevating rod 26 is raised in the z direction by a Z-axis servo motor (see FIG. 2). As a result, the workpiece W gripped by the loader chuck 30 can be conveyed from the first position 34 to the second position 36, and the workpiece W can be set or recovered in the machine tool 37.

In the present embodiment, when the work W is transported from the first position 34 to the second position 36 by the gantry loader 20, the lifting rod 26 is raised while the traveling platform 24 is moved in the x direction. The work W is conveyed. On the other hand, after moving the traveling platform 24 in the x direction, the lifting rod 26 is raised, or the traveling platform 24 is moved in the x direction after raising the lifting rod 26 to a target height. The work W can be transported to the second position 36, but the transport can be completed in a shorter time if the movement of the carriage 24 and the lifting of the lifting rod 26 are performed in parallel.

When conveying the workpiece W, the loader chuck 30 tends to vibrate due to inertial force or natural frequency. If the vibration is large, an insertion error into the machine tool 37 or the like occurs. Therefore, the insertion is performed after the vibration is attenuated. In this embodiment, the PC 10 makes it difficult to cause the vibration (hereinafter referred to as vibration suppression). (Referred to as control input) and input to the gantry loader 20, an operation in which vibration is suppressed can be performed, so that the next process can be performed in a short time.

Hereinafter, a method for determining the vibration suppression control input for the time deformation system in the PC 10 will be described in detail. The method of determining the vibration suppression control input for the time-deformation system described here can be applied not only to the first-order mode but also to the higher-order mode vibration. As a form, a method for determining a vibration suppression control input considering only the vibration of the primary mode will be described, and then a method for determining the vibration suppression control input considering even the vibration of the higher order mode will be described.

FIG. 2 is a block diagram showing an electrical configuration of the transport system 1. The PC 10 includes a CPU 11, a ROM 12, a RAM 13, a hard disk drive 14 (hereinafter referred to as HDD 14), and an input / output port 15.

The CPU 11 is a central processing process that comprehensively controls the PC 10, and executes various programs such as a program that executes the process shown in the flowchart of FIG.

The ROM 12 is a non-rewritable memory that stores various control programs executed by the CPU 11 and data necessary for executing the control programs by the CPU 11.

The RAM 13 is a memory for temporarily storing data and programs necessary for various processes executed by the CPU 11. The RAM 13 includes a test input U storage area 13a, a vibration X storage area 13b, a parameter (ω, ζ, k) storage area 13c, a time deformation system frequency ω (t) storage area 13d, and a reference vibration suppression input. and it includes a u _V storage area 13e, and a reference vibration suppression output _{X V} storage area 13f.

The test input U storage area 13a stores a test input U that is input to the X-axis servomotor 40 when performing a test run in which the workpiece W is transported from the first position 34 to the second position 36 (see FIG. 1). It is an area. The test input U is a random input including all frequencies or an input including frequencies in a wide band.

The vibration X storage area 13b is an area for storing the vibration X of the workpiece W measured by the acceleration sensor 49 when the workpiece W is transported from the first position 34 to the second position 36 (see FIG. 1).

The test input U and vibration X will be described with reference to FIG. FIG. 3A is a graph showing the relationship between time and the test input U. FIG. FIG. 3B is a graph showing the speed of the traveling platform 24 when the test input U shown in FIG. 3A is input to the X-axis servomotor 40. When such a test input U is input to the X-axis servomotor 40, for example, the traveling platform 24 is accelerated for 1 second, then travels at a constant speed for 2 seconds, and stops after deceleration for 1 second.

FIG. 3C is a graph showing the relationship between time and the moving distance in the x direction when the test input U is input. The graph shown in FIG. 3C shows that the carriage 24 moves 3 m in the x direction during the conveyance from the first position 34 to the second position 36, and the movement is performed in 4 seconds.

FIG. 3D is a graph showing the relationship between time and arm length in the movement from the first position 34 to the second position 36. As described above, when the test input is input to the X-axis servomotor 40, the traveling platform 24 moves in the x direction, but the Z-axis servomotor 44 is moved at a constant speed during the four seconds during which the movement is performed. By rotating, the elevating rod 26 is raised, and the arm length is shortened from l ₁ to l ₂ at a constant speed as shown in FIG.

FIG. 3E shows an acceleration sensor in the conveyance in which the movement in the x direction based on the test input U shown in FIG. 3A and the fluctuation of the arm length as shown in FIG. 49 is a graph showing the vibration X of the workpiece W measured by No. 49. As shown in FIG. 3 (e), it can be seen that vibration with a large amplitude occurs during acceleration from 0 to 1 second and deceleration from 3 to 4 seconds. Moreover, it can be seen that residual vibration appears even after the end of the transfer due to the large vibration generated during the transfer. The vibration X measured by the acceleration sensor 49 is stored in the vibration X storage area 13b.

Returning to FIG. The parameter (ω, ζ, k) storage area 13 c is an area for storing parameters of vibrations that occur during conveyance from the first position 34 to the second position 36. Here, the natural frequency ω, the damping coefficient ζ, and the process gain k are stored as parameters. These parameters are identified by the following procedure. First, a time-series test input U as shown in FIG. 3A and a time-series vibration X as shown in FIG. The transfer function G is determined by obtaining the frequency response at each sampling time in the conveyance to the two positions 36. The transfer function G is a function represented by the following equation (2).

Then, according to the created transfer function G, the natural frequency ω, the damping coefficient ζ, and the process gain k are identified by the method of least squares at each sampling time so that the transfer function of equation (2) is fitted to the frequency response. To do.

FIG. 4 is a frequency-gain diagram showing a vibration model at time t = 2 as an example, and is a graph showing the frequency on the horizontal axis and the gain of the transfer function G on the vertical axis. In the frequency-gain diagram shown in FIG. 4, the natural frequency ω is a parameter corresponding to the frequency at which the gain of the transfer function G exhibits a peak. Further, the attenuation coefficient ζ is a parameter obtained based on the half-value width υ ₂ -υ ₁ . The process gain k is a parameter obtained based on the peak value.

Returning to FIG. The time deformation system frequency ω (t) storage area 13d is an area for storing the time deformation system frequency ω (t).

The time deformation system frequency ω (t) will be described with reference to FIG. FIG. 5 is a graph showing the time deformation system frequency ω (t). As shown in FIG. 5, the time-deformation system frequency ω (t) is a correspondence relationship between time and the natural frequency ω in conveyance from the first position 34 to the second position 36. As the arm length is shorter, the natural frequency ω is higher. Therefore, as shown in FIG. 3C, when transport is performed such that the arm length gradually decreases with time, as shown in FIG. The natural frequency ω increases. The correspondence between the fluctuation of the arm length and the natural frequency ω is stored as the time deformation system frequency ω (t) in the time deformation system frequency ω (t) storage area 13d.

Here, as shown in FIG. 5, in the conveyance from the first position 34 to the second position 36, the natural frequency ω varies from 2 [Hz] to 3 [Hz]. Therefore, an intermediate value in the variation range, for example, 2.5 [Hz], shall be defined as the reference natural frequency omega _V. In other words, when the arm length is changed from l ₁ to l ₂ in the conveyance from the first position 34 to the second position 36, the natural vibration corresponding to the average arm length (l ₁ + l ₂ ) / 2 in the change. the number ω, defined as the reference natural frequency ω _V.

Returning to FIG. Reference vibration suppression input u _v storage area 13e is an area for storing a reference vibration suppression input u _v. Reference vibration suppression input u _v is a reference natural frequency omega _V, which is the input determined based on the reference specific damping coefficient of the vibration number ω _V ζ _V. The reference vibration suppression input u _v is the reverse phase method, which is an input for suppressing vibration.

Referring to FIG. 6, a description will be given reference vibration suppression input u _v. 6, first the input A ₁ included in the reference vibration suppression input u _v, is a diagram schematically showing a second input A _2. Here, as shown in FIG. 6, the first input A ₁ and the second input A ₂ are the same as the second input A ₂ when the magnitude of the first input A ₁ is “1”. The size is in a relationship represented by K. Further, the second input A ₂ is added after the time ΔT after the first input A ₁ is added. By using such a first input A ₁ and a reference vibration suppression input u _v and a second input A _2, vibration and is based on the vibration and the second input A ₂ based on the first input A ₁ It becomes an opposite phase and cancels each other out, so that the vibration with the natural frequency ω _V can be suitably suppressed. The second input A ₂ of size K, the timing ΔT the second adding input A ₂ is calculated by the arithmetic expression shown in FIG. 6, the primary mode known for the vibration suppression input calculating the Since this is an equation, detailed description is omitted.

Returning to FIG. Reference vibration suppression output X _v storage area 13f is an area for storing the reference vibration suppression output X _v. The reference vibration suppression output X _v is the arm length as a constant _{(l 1 + l 2) /} 2, a vibration output when the normal vibration suppression input u _v entered in the X-axis servo motor 40. As described above, since the reference vibration suppression input u _v is an input which can be suitably suppress the vibration of the reference natural frequency omega _V, the reference vibration suppression output X _v is an oscillation is suppressed output And can be calculated using the following equation of state (3).
However,
X _V1: deflection angle X _V2 of the reference vibration suppression Output _{X v:} reference vibration suppression output _{X v} shake angular velocity

Here, in the conveyance from the first position 34 to the second position 36, the arm length varies from l ₁ to l ₂ during the movement in the x direction, so that the natural frequency ω varies from time to time, and the reference also the vibration suppressing input u _v as the input as it is, not the output of vibration as the reference vibration suppression output X _v is suppressed.

7, when input reference vibration suppression input u _v, is a graph showing a result of simulating the transport from a first position 34 to the second position 36. 7 (a) is a graph showing a reference vibration suppression input _{u v.} As described above, according to the reference vibration suppression input u _v , the second input A ₂ for canceling the vibration caused by the input is added after the first input A ₁ . As shown, the acceleration is both increased and decreased in two stages. 7 (b) is, when the reference vibration suppression input u _v was added to the X-axis servo motor 40 is a graph representing the velocity of the traveling block 24. As shown in FIG. 7 (b), if you enter the normal vibration suppression input u _v, when compared to a trapezoidal velocity shown in FIG. 3 (b), a gradual speed increase immediately before the constant-speed running, It can also be seen that the deceleration immediately after traveling at a constant speed is performed gradually.

FIG. 7C is a graph showing the vibration of the workpiece W during the conveyance from the first position 34 to the second position 36. As shown in FIG. 7C, compared with the vibration X in the case where the vibration suppression control is not performed (see FIG. 3E), the vibration is suppressed, but a sufficient vibration suppression effect is not obtained. In addition, residual vibration is observed after the conveyance is completed.

Therefore, in the method for determining the vibration suppression control input for the time deformation system of the present embodiment, the arm length is calculated using the reference vibration suppression input u _v , the reference vibration suppression output X _v, and the time deformation system frequency ω (t). The vibration suppression control input u (t) reflecting the fluctuation of As a result of earnest research, the inventor has derived the following equation (4) for calculating a vibration suppression control input u (t) that can obtain a high vibration suppression effect even in a conveyance with a variation in arm length. . In addition, the following (4) Formula is a formula corresponding to (1) Formula described in the claim.
However u _v: standard vibration suppression input X _v: reference vibration suppression output

The above equation (4) expresses the method for determining the vibration suppression control input u (t) as an equation. FIG. 8 is a block diagram showing an algorithm for determining the vibration suppression control input u (t) shown in the equation (4).

Hereinafter, the flow up to the derivation of the above equation (4) will be described.

In the conveyance from the first position 34 to the second position 36, the natural frequency at each time t is expressed by the time-deformation system frequency ω (t) (see FIG. 5), so the vibration suppression control input u (t ) Is expressed by the following equation (5) using the time-deformed system frequency ω (t).
However,
X ₁ : Swing angle when the vibration suppression control input u (t) is input X ₂ : Swing angular velocity when the vibration suppression control input u (t) is input The reference vibration suppression output X _v obtained by the above equation (3) , since a vibration is suppressed output, the output X of the state equation of the expression (5) is equal to the reference vibration suppression output X _v, so that the vibration is suppressed. Thus, (5) place the output X and (3) of the reference vibration suppression output _{X v} in the equation. That is, the following formula (6) is established.
Then, the following equation (7) is established from the equations (3) and (6).
By arranging the equation (7), the above equation (4) that can obtain the vibration suppression control input u (t) is derived.

FIG. 9 shows the work from the first position 34 to the second position 36 when the vibration suppression control input u (t) determined according to the above equation (4) and the vibration suppression control input u (t) are input. It is a graph which shows the result of having simulated the conveyance of W. FIG. 9A is a graph showing the vibration suppression control input u (t). As shown in FIG. 9 (a), the vibration suppression control input u (t) is further smoothly changes than the reference vibration suppression input u _v shown in Figure 7 (a).

FIG. 9B is a graph showing the speed of the traveling platform 24 when the vibration suppression control input u (t) is applied to the X-axis servo motor 40. FIG. 9C is a graph showing the vibration of the workpiece W during conveyance from the first position 34 to the second position 36. From FIG. 9C, it can be seen that a high damping effect is obtained by the vibration suppression control input u (t). In particular, when compared with FIG. 7C, it is observed that the residual vibration disappears in a short time after the end of conveyance.

Returning to FIG. The HDD 14 is a hard disk drive, and stores a vibration suppression control input calculation program 14a. The vibration suppression control input calculation program 14a is a program that executes the processing shown in the flowchart of FIG. Note that the vibration suppression control input u (t) determined by the processing shown in FIG. 10 is stored in the HDD 14, read as necessary, and output to the gantry loader 20.

The input / output port 15 performs signal input / output control between the PC 10 and the gantry loader 20. The CPU 11, ROM 12, RAM 13, HDD 14, and input / output port 15 are connected to each other via a bus.

The gantry loader 20 includes an X-axis servo controller 38, an X-axis servo motor 40, a Z-axis servo controller 42, a Z-axis servo motor 44, an X-axis rotary encoder 46, a Z-axis rotary encoder 48, and an acceleration sensor 49. And are provided.

The X-axis servo controller 38 receives a command from the PC 10 and outputs a drive command signal to the X-axis servo motor 40. The X-axis servo motor 40 receives the drive command signal from the X-axis servo controller 38 and drives the traveling platform 24.

The Z-axis servo controller 42 receives a command from the PC 10 and outputs a drive command signal to the Z-axis servo motor 44. The Z-axis servo motor 44 receives the drive command signal from the Z-axis servo controller 42 and moves the lifting rod 26 up and down.

The X-axis rotary encoder 46 is for measuring the acceleration of the X-axis servomotor 40 and the speed of the traveling platform 24 and inputting them to the PC 10. The Z-axis rotary encoder 48 is for measuring the arm length and inputting it to the PC 10. The acceleration sensor 49 is provided on the loader chuck 30, and measures the vibration of the work W gripped by the loader chuck 30 and inputs it to the PC 10.

FIG. 10 is a flowchart showing the vibration suppression control input u (t) determination process executed in the PC 10. The vibration suppression control input u (t) determination process is started when the operator designates the first position 34 and the second position 36 and instructs the start of the vibration suppression control input u (t) determination process in the PC 10. It is processing to do.

First, based on the x-direction distance between the first position 34 and the second position 36, the test input U is determined and stored in the test input U storage area 13a (see FIG. 2) (S1). Specifically, the test input U is determined so that the traveling base 24 is driven at a trapezoidal speed as shown in FIG.

Then, the arm length _{l 1} of the first position 34 on the basis of the arm length _{l 2} of the second position 36, to determine the inputs to the Z-axis servo motor 44 (S2). This input is an input determined so that the arm length varies from l ₁ to l ₂ at a constant speed while the carriage 24 moves in the x direction by the test input U.

Next, the test input U determined in S1 is output to the X-axis servo motor 40 to cause the traveling platform 24 to travel in the x direction, and during the movement in the x direction, the input determined in S2 causes Z to be generated. The shaft servomotor 44 is driven, and the test run is performed by changing the arm length from l ₁ to l ₂ (S3). This test running is performed with the work W being held by the loader chuck 30.

Next, the vibration X of the workpiece W acquired by the acceleration sensor 49 is stored in the vibration X storage area 13b (see FIG. 2) (S4). Then, the test input U and the vibration X are each subjected to a short time Fourier transform to be converted into a frequency response (S6).

Next, a transfer function is obtained from the frequency response, and the natural frequency ω, the damping coefficient ζ, and the process gain k for each time are identified by the least square method and stored in the parameter storage memory 13c (see FIG. 2) (S8). . Then, based on the identified natural frequency ω for each time, the time-deformation system frequency ω (t) (see FIG. 5) representing the correspondence between the variation of the arm length and the natural frequency ω is acquired. (S10).

Then, based on the time variations system angular frequency omega (t), to determine a reference natural frequency ω _V (S12). Then, to get the reference vibration suppression input u _v which it is possible to suppress the vibration of the reference natural frequency omega _V, it is stored in the reference vibration suppression input u _v storage area 13e (S14).

Then, based on the reference oscillation suppression input u _v, using the state equation, the simulation determines the reference vibration suppression output X _v by (S16). Then, a reference vibration suppression input u _v, and the reference oscillation suppression output X _v, when based on the modified system angular frequency omega (t), equation (4) with indicated are vibration suppression control input u (t) is determined And stored in the HDD 14 (S18).

According to the determination method of the vibration suppression control input for the time deformation system of the first embodiment, it is possible to determine the vibration suppression control input u (t) considering the variation of the natural frequency ω accompanying the arm length variation. By inputting the vibration suppression control input u (t) to the X-axis servomotor 40, a high vibration damping effect can be obtained regardless of the fluctuation of the arm length.

In addition, the natural frequency ω, the damping coefficient ζ, and the process gain k are identified by the test running (experiment) from the relationship between the vibration X measured in the test running and the test input U. The vibration suppression control input u (t) can also be determined for a system that was originally unknown.

Further, since the time deformation system frequency ω (t) is obtained from the relationship between the test input U and the vibration X during the test run, the test run for obtaining the time deformation system frequency ω (t) is performed again. There is no need to do it and the work is easy.

In addition, since the determined vibration suppression control input u (t) is stored in the HDD 14, it is repeatedly used in batch-type transport in which transport from the first position 34 to the second position 36 is repeated, and simple processing is performed. High vibration control effect can be obtained.

The reference vibration suppression input u _V necessary for determining the vibration suppression control input u (t) is the same operation as known antiphase input control can be easily shaped. Therefore, the vibration suppression control input u (t) can be easily determined.

In the first embodiment, based on the first input A ₁ and a second input A ₂ described with reference to FIG. 6, the reference vibration suppression input u _V described as shaping, reference calculation method for obtaining the vibration suppression input u _V is not limited to this.

Referring to FIG. 11, a description will be given of another operation method for obtaining a reference oscillation suppression input u _V. Figure 11 is a diagram schematically showing input included in the reference vibration suppression input u _v, it is a view corresponding to FIG. According to the calculation method shown in FIG. 6, after the first input A _1, the second input A ₂ for the vibration suppression after ΔT was added. In contrast, according to the calculation method shown in FIG. 11, after the first input A _1, for suppressing the vibration due to the first input A _1, the second input A ₂ and the third input A ₃ is added. The timing of adding the size 2K of the second input _{A 2,} the size ^{K 2} timing [Delta] T, and a third input _{A 3} adds the second input _{A 2,} the input _{A 3} of the third An arithmetic expression for obtaining 2ΔT is as described in FIG.

As shown in FIG. 11, the vibration due to the first input A _1, when shaped to suppress normal vibration suppression input u _v in the second input A ₂ and the third input A _3, robustness A high vibration suppression control input u (t) can be obtained. In other words, using the vibration suppression control input u (t) obtained in this manner, the vibration suppression control input u (t) is stable regardless of wear over time, voltage fluctuation, arm length measurement error, and workpiece W mass variation. High vibration control effect can be obtained. The flow up to the derivation of the arithmetic expression shown in FIG. 11 will be described in detail later.

Next, a second embodiment will be described. In the first embodiment described above, the case where only the vibration in the first-order mode occurs has been described. In the second embodiment, the case where the vibration in the higher-order mode occurs will be described. Note that in the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

Also in the second embodiment, as in the first embodiment, first, a time-series test input U as shown in FIG. 3A and a time-series vibration X as shown in FIG. By performing the short time Fourier analysis, the transfer function G representing the vibration model is created for each sampling time in the conveyance from the first position 34 to the second position 36.

Here, the case where vibration occurs up to the secondary mode will be described. FIG. 12A is a frequency-gain diagram showing a vibration model at time t = 2, and corresponds to FIG. In the frequency-gain diagram shown in FIG. 12A, two peaks appear. The frequency on the low frequency side is identified as the natural frequency of the primary mode, and the frequency on the high frequency side is identified as the natural frequency of the secondary mode.

Even when vibration up to the secondary mode occurs, the average arm length when the arm length is changed from l ₁ to l ₂ in the conveyance from the first position 34 to the second position 36 as in the first embodiment. A reference natural frequency ω _V corresponding to (l ₁ + l ₂ ) / 2 is determined. In this case, since the reference natural frequency ω _V is composed of the natural frequency ω _v1 of the primary mode and the natural frequency ω _v2 of the secondary mode, it can be expressed by the following equation (8). A combined wave of the vibration of the natural frequency ω _v1 of the primary mode and the vibration of the natural frequency ω _v2 of the secondary mode corresponds to the vibration measured by the acceleration sensor 49.

Next, as in the first embodiment, a reference vibration suppression input u _v for suppressing the reference natural frequency ω _v is obtained.

Figure 12 Referring to (b), the reference vibration suppression input u _v in the case of considering up to the second order mode will be described. FIG. 12 (b), first the input _{A 1} included in the reference vibration suppression input _{u v} considering up to the second order mode, the second input _{A 2,} and the third input _{A 3,} of the fourth the input a ₄ is a diagram schematically showing. As shown in FIG. 12B, when the magnitude of the first input A ₁ is “1”, the second input A ₂ is represented by a magnitude K ₁ , and the third input A ₃ is The magnitude is represented by K ₂ , and the fourth input A ₄ is in a relationship represented by magnitude K ₁ K ₂ .

Then, after adding the first input _{A 1,} after a time [Delta] T _1, a second input _{A 2} is applied, a third input _{A 3} is added after a time [Delta] T _2, first after a time [Delta] T ₁ + [Delta] T ₂ 4 input _{a 4} of is added. The first input _{A 1,} the second input _{A 2,} the third input _{A 3,} the use of the reference vibration suppression input _{u v} include a fourth input _{A 4,} based on the first input _{A 1} The vibration and the vibration based on the subsequent input cancel each other, and even the vibration including the secondary mode can be preferably suppressed.

Note that ΔT ₁ , ΔT ₂ , K ₁ , and K ₂ are calculated by the arithmetic expression shown in FIG. To indicate operation expressions FIG. 12 (b), in order to shape the reference vibration suppression input u _v considering up to the second order mode, the result of the present inventors have conducted extensive studies, is an expression of the derived new. The process up to deriving this arithmetic expression will be described in detail later. Further, the present inventors, since the derivation operation expression for shaping the reference vibration suppression input u _v considering up to the third order mode will be described in detail later also this.

This way, the normal vibration suppression input u _v is shaped, similarly to the method for determining when the vibration suppression control input to deformation system of the first embodiment, the reference vibration suppressing input u _v and a reference vibration suppression output X _v Then, using the time-deformation system frequency ω (t), the vibration suppression control input u (t) reflecting the variation of the arm length is calculated by the following equation (9). The following equation (9) is an equation in which the equation (4) described in the first embodiment is expanded to the n-order mode (n is a positive integer), and is described in the claims (1) This is an expression corresponding to the expression.
However u _V: normal vibration suppression input X _V: target in the case where the input mass of the conveyed object, the liquid level, and the constant length of the arm when the arm is interposed, a reference vibration suppression input u _V to the driving device Vibration B ′ (t) of transported object: A _{V as} shown in the above “Formula 5”: B _{V as} shown in the “Formula 6” X: As shown in the above “Formula 7” _V : n is the number of modes as shown in the above “Equation 8”

According to the vibration suppression control input determination method for the time deformation system of the second embodiment, when the reference natural frequencies ω _{V of} a plurality of modes are identified, the reference vibration suppression inputs u _V corresponding to the plurality of modes are acquired. and can be based on the reference oscillation suppression input u _V corresponding to the plurality of modes, determined vibration suppression control input u a (t). Therefore, by inputting the vibration suppression control input u (t) to the X-axis servomotor 40, it is possible to obtain a high vibration suppression effect even for vibrations including higher-order modes.

In order to make the explanation easy to understand in the second embodiment described above, first, description has been made up to the secondary mode, but the vibration suppression control input determination method for the time deformation system of the second embodiment has three or more modes. It is also applicable to. Therefore, the case where the third mode is taken into consideration will be described below. Similarly, when vibration occurs up to the tertiary mode, the average arm length (l ₁ + l ₂ ) in the case where the arm length is changed from l ₁ to l ₂ in the conveyance from the first position 34 to the second position 36. The reference natural frequency ω _V corresponding to / 2 is determined. In this case, the reference natural frequency ω _V is the primary mode natural frequency ω _V1 , the secondary mode natural frequency ω _V2, and the tertiary mode. It consists of the natural frequency ω _{V3 of the} mode.

Figure 13 is a diagram schematically showing the first input A ₁ included in the reference vibration suppression input u _v considering up to the third order mode until input A ₈ of the eighth. As shown in FIG. 13, when the magnitude of the first input A ₁ is “1”, the second input A ₂ is represented by a magnitude K ₁ , and the third input A ₃ is represented by a magnitude. represented by K _2, the fourth input _{a 4} of a relationship of magnitude is represented by _K 1 _{K 2.}

Furthermore, the fifth input A ₅ is represented by K ₃ , the sixth input A ₆ is represented by K ₁ K ₃ , and the seventh input A ₇ is represented by K ₂ K _3. The eighth input A ₈ has a relationship represented by K ₁ K ₂ K ₃ in magnitude.

Then, after adding the first input _{A 1,} after a time [Delta] T _1, a second input _{A 2} is applied, a third input _{A 3} is added after a time [Delta] T _2, first after a time [Delta] T ₁ + [Delta] T ₂ 4 input _{a 4} of is added. Also, after time ΔT ₃ , the fifth input A ₅ is added, after time ΔT ₁ + ΔT ₃ , the sixth input A ₆ is added, and after time ΔT ₂ + ΔT ₃ , the seventh input A ₇ is added, and time After ΔT ₁ + ΔT ₂ + ΔT ₃ , the eighth input A ₈ is applied.

By using such a first input A ₁ from the eighth reference vibration suppressing input u _v including an input A ₈ of the first based on the input A ₁ vibration and vibration and cancel each other based on subsequent input Even vibration including up to the tertiary mode can be suitably suppressed.

Then, using the reference vibration suppression input u _v , the reference vibration suppression output X _v determined in this way, and the time-deformation system frequency ω (t), the vibration suppression control input u that reflects the variation of the arm length. (T) is calculated by the above equation (9). In this way, it is possible to determine the vibration suppression control input u (t) that can obtain a high vibration suppression effect even for vibration including the tertiary mode.

Note that ΔT ₁ , ΔT ₂ , ΔT ₃ , K ₁ , K ₂ , and K ₃ are calculated by the arithmetic expressions shown in FIG. Arithmetic expression shown in FIG. 13, in order to shape the reference vibration suppression input u _v considering up to the third order mode, the result of the present inventors have conducted extensive studies, the derived from an expression, up to this arithmetic expression derived The process will be described in detail later.

Next, a third embodiment will be described. In the first embodiment and the second embodiment described above, the test travel is performed only once and the vibration suppression control input u (t) is determined. However, the third embodiment repeats the test travel. Further, this is a form in which an even more accurate vibration suppression control input u (t) is to be determined. Note that in the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

The repeated identification process will be described with reference to FIG. FIG. 14 is a flowchart showing the repeated identification process executed in the PC 10 of the third embodiment. This iterative identification process is a process that is activated in the PC 10 when an operator instructs the start of the repetitive identification process. In this repeated identification process, the vibration suppression control input u (t) has already been determined by the vibration suppression control input u (t) determination process (see FIG. 10), and the determined value is stored in the HDD 14. If executed.

First, the vibration suppression control input u (t) stored in the HDD 14 is read out and output to the X-axis servo motor 40, thereby causing the carriage 24 to travel in the x direction and the movement in the x direction. In the meantime, the Z-axis servo motor 44 is driven to vary the arm length from l ₁ to l ₂ to perform test running (S20). In this test running, the loader chuck 30 grips the workpiece W having the same mass as the workpiece W gripped by the loader chuck 30 when the previous vibration suppression control input determination process (see FIG. 10) is executed. Assumed to be performed.

Next, the vibration X acquired by the acceleration sensor 49 during the test run is displayed on the monitor of the PC 10 (S22). Then, the operator is inquired whether the vibration output result is satisfactory (S24). When the operator who sees the monitor is satisfied with the vibration output result (S24: Yes), the vibration suppression control input u (t) read out in the process of S20 is stored in the HDD 14 again (S26), and the process ends. This is because it has become clear that a sufficient damping effect can be obtained with the vibration suppression control input u (t) determined up to the previous time.

On the other hand, if the operator looking at the monitor is dissatisfied with the vibration output result (S24: No), a process of redetermining the vibration suppression control input u (t) is performed.

That is, in the process of S20, the vibration suppression control input u (t) input as the test input and the measured vibration X are each subjected to short time Fourier transform and converted to a frequency response (S28).

Then, a transfer function is obtained from the frequency response, the natural frequency ω, the damping coefficient ζ, and the process gain k for each time are identified by the least square method, and stored in the parameter storage memory 13c (see FIG. 2) (S30). Here, more accurate parameters can be obtained. That is, in the above-described vibration suppression control input determination process (see FIG. 10), in order to examine all frequency components, random inputs including all frequencies or test inputs including a wide range of frequencies are input. Energy is dispersed in the band, and a signal component that is not so strong in the band of interest cannot be obtained. Therefore, depending on conditions, it is easily affected by noise, and there is a possibility that parameters cannot be accurately identified. On the other hand, in this repeated identification process, since the vibration suppression control input u (t) is input as a test input, a stronger signal component can be obtained in the band of interest, and the parameters can be identified with high accuracy.

Then, in the following steps, based on more accurate parameters, when modified system angular frequency omega (t) is acquired (S32), also the reference natural frequency omega _V is determined (S34), and the reference vibration suppression input _{u V} is determined (S36).

Then, based on the reference oscillation suppression input u _v, normal vibration suppression output X _v is determined (S38), the reference vibration suppression input u _v, and the reference oscillation suppression output X _v, the number modification system vibration when omega (t ), The vibration suppression control input u (t) represented by the above equation (4) or (9) is determined (S40). Therefore, it is possible to determine the vibration suppression control input u (t) having a higher vibration damping effect than when it was determined last time.

Then, returning to the process of S20, the determined vibration suppression control input u (t) is output to the X-axis servo motor 40, thereby causing the traveling platform 24 to travel in the x direction and during the movement in the x direction. Then, the Z-axis servo motor 44 is driven to vary the arm length l ₁ to l ₂ to perform the test run again (S20). Then, the vibration X acquired by the acceleration sensor 49 during the test run is displayed on the monitor of the PC 10 (S22), and an inquiry is made to the operator as to whether or not the vibration output result is satisfactory (S24). In this way, the process is repeated until the operator is satisfied with the vibration output result.

According to the repeated identification process of the third embodiment, the vibration suppression control input u (t) determined up to the previous time is input during the test travel, so that the vibration suppression control input u (t) with higher accuracy is input. Can be determined. As a result of repeated simulations, the present inventor can identify a parameter with higher accuracy as the number of repetitions of the repeated identification process is increased. As a result, the vibration suppression control has a higher damping effect. It was found that the input u (t) can be determined.

Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. Can be inferred.

For example, in the above-described embodiment, the vibration suppression control input u (t) is input to the gantry loader 20, but the control target is not limited to the gantry loader 20, and various conveyances such as a crane and a robot arm used in a factory. It can be applied to the device.

With reference to FIG. 15, a modified example of the control target by the vibration suppression control input u (t) will be described. FIG. 15 is a diagram illustrating a liquid transport device 50 that is used in place of the gantry loader 20 of the embodiment. The liquid transport device 50 is a device for storing the liquid 52 in the container 54 and transporting it by the traveling table 56. In the transport process, the liquid is dropped from a dropping device 58 that translates with the traveling table 56. is there. The container 54 is provided with a liquid level sensor 60 for measuring vibration of the liquid level. According to such a transfer system, the mass and the liquid level (liquid level height) of the liquid 52 that is the transfer object fluctuate in the process of moving the traveling platform 56.

Even in such a transport system, the natural frequency ω fluctuates due to the fluctuation of the liquid level of the liquid 52 during transport, but the vibration suppression control input u (t) determined by the method described in the embodiment is used for traveling. By inputting to the drive device of the base 56, a high vibration damping effect can be obtained. Therefore, even if the traveling table 56 is traveled at a high speed, the liquid 52 can be prevented from overflowing and splashing and transported at a high speed. Even when the liquid 52 is transported while flowing out of the container 54, the natural frequency ω varies due to the variation in the liquid level. Similarly, the vibration suppression control input u (t) is used as the driving device for the traveling platform 56. A high vibration damping effect can be obtained by inputting to.

In the above-described embodiment, the vibration suppression control input u (t) is determined using the time-deformation system frequency ω (t), which is the correspondence between time and the natural frequency. Other than the time-deformation system frequency ω (t) may be used as long as it represents the correspondence between the fluctuation of the mass of the object, the liquid level, or the length of the arm and the natural frequency. For example, the vibration suppression control input u (t) determination process (see FIG. 10) or the repeated identification process is performed so as to determine the vibration suppression control input u (t) using the natural frequency ω (l) for each arm length. (See FIG. 14) may be modified. Alternatively, the vibration suppression control input u (t) may be determined using the natural frequency ω (h) for each liquid level h of the conveyed object.

In the above-described embodiment, the natural frequency ω corresponding to the average arm length (l ₁ + l ₂ ) / 2 in the process of variation is determined as the reference natural frequency ω _V , but the reference natural frequency ω is used. determination of _V is not limited thereto, may define natural frequency omega of any point in the transport from the first position 34 to the second position 36 as a reference natural frequency omega _V.

In the above-described embodiment, it has been described that only the conveyance from the first position 34 to the second position 36 is performed. However, the movement distance in the x direction is the same, and the arm during the movement in the x direction is the same. For conveyances having the same variation in length, a vibration suppression effect can be obtained using the same vibration suppression control input u (t).

In the above-described embodiment, the vibration suppression control input u (t) determined using the expression (4) or (9) is used as it is. However, the expression (4) or (9) is used. Based on the vibration suppression control input u (t) determined in this way, a control input for the drive device may be obtained.

The flow up to deriving each arithmetic expression used in the above description will be described below. <Input magnitude and timing for the primary mode (corresponding to FIG. 6)> The amplitude of vibration by N impulse inputs is given by equation (18).
here
A _amp = 0 is required to suppress vibration. Therefore, equation (18) becomes
It becomes. here
To become equation (19)
Equation (20) can be summarized as Equation (21).
When there are two impulse inputs, Equation (21) becomes Equation (22).
By setting the initial input to t ₁ = 0 and A ₁ = 1, the solution of equation (22) is
It becomes. That is, the magnitude and timing of the input (impulse input) for the primary mode are as shown in FIG.

<Size and timing when there are three inputs (corresponding to FIG. 11)> A new constraint is added to increase the robustness of the inputs against model errors due to variations in the natural frequency of the system. The formula to be added is shown in Formula (24). This is a derivative of equation (24) with frequency ω.
Increase the number of impulse inputs from 2 to 3, and find 3 inputs from equation (25).
By setting the initial input t ₁ = 0 and A ₁ = 1, the solution of equation (25) is
It becomes. Therefore, the size and timing when there are three inputs (impulse inputs) are as shown in FIG.

<Input size and timing for secondary mode (corresponding to FIG. 12B)>
When the system vibration is taken into consideration up to the second order mode and the system transfer function is expressed by the equation (27), the impulse input is obtained by solving the equations (28) to (30).
By setting the initial input t ₁ = 0 and A ₁ = 1, the solution of equation (28) is
The solution of equation (29) is
The solution of equation (30) is
It becomes. That is, the magnitude and timing of the input (impulse input) for the secondary mode are as shown in FIG.

<Input size and timing for tertiary mode (corresponding to FIG. 13)>
When the system vibration is taken into account up to the third order mode and the system transfer function is expressed by equation (34), the impulse input can be obtained by solving equations (35) to (41).
By setting the initial input t ₁ = 0 and A ₁ = 1, the solution of equation (35) is
The solution of equation (36) is
The solution of equation (37) is
The solution of equation (38) is
The solution of equation (39) is
The solution of equation (40) is
The solution of equation (41) is
It becomes. That is, the magnitude and timing of the input (impulse input) for the tertiary mode are as shown in FIG.

It is a front view of a conveyance system to which an embodiment of the present invention is applied. It is a block diagram which shows the electrical structure of the conveyance system shown in FIG. (A) is a graph which shows the relationship between time and the test input U. FIG. (B) is a graph showing the speed of the platform when the test input U shown in (a) is input to the X-axis servomotor. (C) is a graph showing the relationship between time and the movement distance in the x direction when the test input U is input. (D) is a graph which shows the relationship between time and arm length in the movement from a 1st position to a 2nd position. (E) is a graph which shows the vibration X of the workpiece | work W measured by the acceleration sensor. It is a frequency-gain diagram which shows the vibration model in time t = 2. It is a graph which shows time deformation system frequency omega (t). The first and the input A ₁ included in the reference vibration suppression input u _v, is a diagram schematically showing a second input A _2. (A) is a graph showing a reference vibration suppression input _{u v.} (B) is the reference vibration suppression input u _v, when added to the X-axis servomotor is a graph showing the running board of the speed. (C) is a graph which shows the vibration of the workpiece | work W during conveyance from a 1st position to a 2nd position. It is the figure which showed the algorithm which calculates | requires vibration suppression control input u (t) with the block diagram. (A) is a graph which shows vibration suppression control input u (t). (B) is a graph showing the speed of a traveling stand when the vibration suppression control input u (t) is applied to the X-axis servomotor. (C) is a graph which shows the vibration of the workpiece | work W during conveyance from a 1st position to a 2nd position. It is a flowchart which shows the vibration suppression control input u (t) determination process performed in PC. Three inputs included in the reference vibration suppression input u _v is a view schematically showing a view corresponding to FIG. (A) is a frequency-gain diagram showing a vibration model at time t = 2, and corresponds to FIG. (B), the first and the input _{A 1} included in the reference vibration suppression input _{u v} considering up to the second order mode, the second input _{A 2,} and the third input _{A 3,} the fourth input A ₄ is a diagram schematically showing ₄ . The up third mode from the first input A ₁ included in the reference vibration suppression input u _v of considering input A ₈ of 8 is a diagram schematically showing. It is a flowchart which shows the repetition identification process performed in PC of 3rd Embodiment. It is a figure which shows the liquid conveying apparatus used instead of the gantry loader of embodiment. It is a figure which shows typically an example of the conventional conveyance system. (A) is a graph which shows the input acceleration input into a motor in the conventional antiphase input control, (b) is a graph which shows the damping effect obtained as a result of giving the input acceleration to a motor . It is a graph which shows the relationship between the arm length L and the natural frequency (omega) in the conveyance system shown in FIG.

DESCRIPTION OF SYMBOLS 1 Conveyance system 10 PC (an example of a computer) 14 HDD (an example of a memory | storage means) 14a Vibration suppression control input calculation program 24 with respect to a time deformation system 24 A traveling stand (an example of a conveyance body) 34 1st position 36 2nd position 40 X-axis servo Motor (example of drive unit) 44 Z-axis servo motor (arm length variation means) W Workpiece (example of conveyed object) l ₁ , l ₂ arm length u (t) Vibration suppression control input u _V reference vibration suppression input ω (t) Correspondence relationship between variation in mass, liquid level or arm length of conveyed object and natural frequency S10, S32 Time deformation system frequency acquisition step, time deformation system frequency acquisition means, time deformation system Frequency acquisition steps S14, S36 Reference vibration suppression input acquisition step, reference vibration suppression input acquisition means, reference vibration suppression input acquisition steps S18, S40 Vibration suppression control Force determining step, the vibration suppression control input determining means, the vibration suppression control input determining step S3, S20 test step S4, S22 vibration measurement step S8, S30 parameter identification step S20~S40 repeating step

Claims (11)

Vibration when changing the mass, liquid level, or length of the arm interposed between the transport body and the transported object held by the transport body while moving the transport body by the driving device Is a vibration suppression control input determination method for a deformation system when determining a vibration suppression control input to be applied to the driving device, and includes a variation in the mass of the transported object, the liquid level, or the length of the arm. , A deformation system frequency acquisition step for acquiring the correspondence with the natural frequency,
Based on the natural frequency when moving the transport body by the driving device, the arm length is constant when the mass of the transported object, the liquid level, and the arm are interposed, and vibration of the natural frequency is performed. A reference vibration suppression input acquisition step for acquiring a reference vibration suppression input for suppressing;
The reference vibration suppression input acquired by the reference vibration suppression input acquisition step, the variation in the mass, liquid level, or arm length of the transferred object and the natural frequency acquired by the time deformation system frequency acquisition step. A vibration suppression control input determination step for determining a vibration suppression control input that reflects the corresponding relationship, and in the vibration suppression control input determination method for the time deformation system described above, the vibration suppression control input determination step includes: A vibration suppression control input determination method for a time-deformation system, characterized by determining a vibration suppression control input based on u (t) in equation (1) .
However, uV: reference vibration suppression input XV: the mass, liquid level of the object to be conveyed, and the arm length when the arm is interposed, and the reference vibration suppression input uV of the object to be conveyed when the reference vibration suppression input uV is input to the driving device. vibration
k i (t) is the process gain of the i-th mode at time t, and ω i (t) is the natural frequency of the i-th mode at time t.
n is the number of modes
A predetermined test input is input to the driving device, and a test process for changing a mass, a liquid level, or an arm length of the object to be transported while the transport body is moved, and the transport by the test process. From the relationship between the vibration measurement process for measuring the vibration of the conveyed object during the movement of the body, the test input input by the test process, and the vibration measured by the vibration measurement process, And a parameter identification step for identifying a reference natural frequency that is a natural frequency when the arm length is constant when the arm is interposed, and the reference vibration suppression input acquisition step includes 2. A vibration suppression for a time-deformation system according to claim 1, wherein a reference vibration suppression input is acquired based on the reference natural frequency identified by the parameter identification step. Please input determination method.
The reference vibration suppression input acquisition step acquires a reference vibration suppression input corresponding to the plurality of modes when the reference natural frequencies of a plurality of modes are identified by the parameter identification step. The vibration suppression control input determination method for the time deformation system according to 2.
In the time deformation system frequency acquisition step, the relationship between the test input input in the test step and the vibration measured in the vibration measurement step, the mass of the transported object, the liquid level, or the length of the arm The vibration suppression control input determination method for the time-deformation system according to claim 2 or 3, wherein a correspondence relationship between the fluctuation of the frequency and the natural frequency is acquired.
The test step is a step of changing a mass, a liquid level, or an arm length of the conveyed object while moving the conveyed object from the first position to the second position, and the time deformation system vibration The number acquisition means acquires a correspondence relationship between a fluctuation in mass, liquid level, or arm length of the transferred object and a natural frequency during the movement of the transferred object from the first position to the second position. The vibration suppression control input determination method for the time deformation system according to any one of claims 2 to 4.
The vibration suppression control input determined by the vibration suppression control input determination step is input as a test input in the test step, and based on the test input, the time deformation system frequency acquisition step, the parameter identification step, The vibration suppression control input determination method for a time-deformation system according to any one of claims 2 to 5, further comprising a repetition step of repeating the reference vibration suppression input acquisition step and the vibration suppression control input determination step. .
The reference vibration suppression input acquired by the reference vibration suppression input acquisition step includes at least one input and one or more inputs that generate vibrations having a phase opposite to that caused by the input. Item 7. A vibration suppression control input determination method for the time deformation system according to any one of Items 1 to 6.
Storage means for storing the vibration suppression control input determined by the method according to any one of claims 1 to 7, a drive device to which the vibration suppression control input stored in the storage means is input, and driving by the drive device And a transport body that holds the object to be transported.
The transport body is driven in the horizontal direction by the driving device and suspends the transported object via an arm. The length of the arm interposed between the transport body and the transported object is The transport system according to claim 8, further comprising arm length changing means for changing.
A transport system that uses the vibration suppression control input determination method for a time deformation system according to claim 1 , wherein the transport body holds a transported object, a drive device that moves the transport body, and the transport body Suppresses vibrations when the mass of the object to be conveyed, the liquid level, or the length of the arm interposed between the object and the object to be conveyed is changed while being moved by the driving device. for a conveyor system comprising a vibration suppression control input determining means to deformation system when determining the vibration suppression control input applied to the drive device, the mass of the object to be conveyed, liquid level, or arms of the length of Deformation system frequency acquisition means for acquiring the correspondence between fluctuation and natural frequency, and the mass of the conveyed object, the liquid level, and the arm length when the arm is interposed, the drive device A vibration suppression control input determination means, comprising: a reference vibration suppression input acquisition means for acquiring a reference vibration suppression input for suppressing the vibration of the natural frequency based on the natural frequency when the transport body is further moved. Is based on the reference vibration suppression input acquired by the reference vibration suppression input acquisition means and the variation in the mass, liquid level, or arm length of the conveyed object acquired by the time deformation system frequency acquisition means. A conveyance system that reflects a correspondence relationship with a frequency and determines a vibration suppression control input by the vibration suppression control input determination method for the time deformation system. 請Motomeko one described, when a vibration suppression control input calculation program which is determined by the vibration suppression control inputs determine how to deformation systems, while moving by a driving device carrier, the held by the carrier In order to suppress vibration when changing the mass, liquid level of the conveyed object, or the length of the arm interposed between the conveyed object and the conveyed object, a vibration suppression control input applied to the driving device is input to the computer. A vibration suppression control input program for a deformation system at the time of calculation, wherein a deformation system frequency is acquired to acquire a correspondence relationship between a natural frequency and a variation in the mass, liquid level, or arm length of the conveyed object Step, and the mass, liquid level of the object to be transported, and the arm length when the arm is interposed A reference vibration suppression input acquisition step for acquiring a reference vibration suppression input for suppressing the vibration of the natural frequency based on the frequency, and the reference vibration suppression input acquired by the time deformation system frequency acquisition step. the mass of the object to be conveyed, liquid level or the fluctuation of the length of the arm, and to reflect the correspondence between the natural frequency, and a vibration suppression control input calculation step of calculating the vibration suppression control input, The vibration suppression control input calculation program for the deformation system when the computer is operated.