JP6631995B2 - Attraction force estimation method and attraction force estimation device - Google Patents

Description

  The present invention relates to an attraction force estimation method and an attraction force estimation device.

  2. Description of the Related Art Conventionally, commercially available permanent electromagnetic holders and permanent electromagnetic attachment / detachment devices that are detachably provided using magnetic force have been used for various purposes. For example, one that fixes a workpiece during processing (for example, see Patent Literatures 1 to 5), one that fixes a safe to prevent theft (for example, see Patent Literature 6), and that temporarily suspends a flying object for fixed point observation and the like (For example, see Non-Patent Document 1).

  In a detachable device that uses such a magnetic force, it is important to know whether sufficient suction force is generated when suctioning a work or flying object, etc., in order to achieve secure and safe suction. It is. Therefore, the present inventors, as shown in FIG. 6, bring the permanent electromagnetic holder 51 close to the adsorption target 1 and adsorb it, and measure the induction electromotive force generated in the electromagnet 52 at the time of the adsorption, so that the induction electromotive force and It has been found that there is a correlation between the attraction force and the possibility of estimating the attraction force without using an additional sensor (for example, see Non-Patent Document 1).

JP 2010-173032 A JP 2010-105079 A JP 2006-224261 A JP-A-5-329732 JP-A-10-328959 JP 2004-197380 A

Keiko Koura, Yoshito Okada, Kazunori Ohno, Satoshi Tadokoro, "Single Performance Evaluation of Multicopter Suction System Using Permanent Magnets and Electromagnets", Proc. Of the 2015 JSME Conference on Robotics and Mechatronics, 2A1-G06

  However, in the method for estimating the attraction force described in Non-Patent Document 1 shown in FIG. 6, the induced electromotive force is not only the attraction force, but also the magnetic flux density that varies greatly depending on the relative speed between the permanent electromagnetic holder 51 and the attraction target 1. It also depends on the rate of change. Since it is difficult to always maintain the same relative speed every time the suction is performed, there is a problem that the relationship between the induced electromotive force and the suction force is not stable, and it is difficult to accurately estimate the suction force.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an attraction force estimation method and an attraction force estimation device capable of accurately estimating an attraction force without using an additional sensor. And

In order to achieve the above object, a method for estimating an attraction force according to the present invention is directed to a magnetic force attachment / detachment device having an attraction member capable of attracting to a ferromagnetic material by a magnetic force, and an electromagnet capable of generating a magnetic force for canceling the magnetic force of the attraction member. In a state where the magnetic force of the attraction body is canceled by the electromagnet, and then brought into contact with the attraction target, and then the power supplied to the electromagnet is changed to attract the attraction body to the attraction object, and the change of the supply power By estimating the attraction force of the attraction body to the attraction target based on the time change of the voltage at the electromagnet, the attraction force is estimated without using an additional sensor for obtaining the attraction force. It is characterized by doing.

  The attraction force estimating method according to the present invention measures the time change of the voltage at the electromagnet from a state where the magnetic force attaching / detaching device is in contact with the attraction target, without being affected by the relative speed between the attraction force attaching / detaching device and the attraction target at all. , Measurements can be made. Therefore, the relationship between the voltage and the attraction force of the obtained electromagnet does not depend on the relative speed between the magnetic force attaching / detaching device and the suction object, and the attraction force at the time of attraction is accurately estimated based on the time change of the voltage at the electromagnet. can do. Further, the attraction force can be obtained only by measuring the voltage at the electromagnet, and there is no need to use an additional sensor.

  In the attraction force estimation method according to the present invention, the time change of the voltage at the electromagnet measured includes a time change of the power supplied to the electromagnet and a time change of the induced electromotive force generated in the electromagnet due to the change of the supplied power. include. The time change of the induced electromotive force generated in the electromagnet depends on the attraction force of the attraction body to the attraction target. For this reason, the attraction force estimation method according to the present invention may measure only the time change of the induced electromotive force generated in the electromagnet as the time change of the voltage of the electromagnet. Further, when changing the power supply to the electromagnet in the attraction force estimation method according to the present invention, it is preferable to change the power supply so that an induced electromotive force is generated in the electromagnet. In addition, any change in the power supplied to the electromagnet can be achieved by reducing the supplied power, stopping the supplied power, or reversing the polarity of the supplied power, as long as the adsorbent is adsorbed to the adsorption target. It may be.

An attraction force estimating apparatus according to the present invention includes a magnetic force attaching / detaching device having an attraction body capable of attracting to a ferromagnetic material by a magnetic force, and an electromagnet capable of generating a magnetic force for canceling the magnetic force of the attraction body, and supplying power to the electromagnet. A power supply unit provided so as to be able to measure the voltage at the electromagnet; and an analysis unit that performs an analysis based on the voltage measured by the voltage measurement unit. It is possible to change the power supplied to the electromagnet, the analysis unit, based on the time change of the voltage in the electromagnet when the power supplied to the electromagnet by the power supply unit is changed, based on the adsorbent It is configured to determine the attraction force, and is configured to estimate the attraction force without using an additional sensor for determining the attraction force .

  The attraction force estimating apparatus according to the present invention can suitably implement the attraction force estimating method according to the present invention. The attraction force estimating device according to the present invention measures the voltage at the electromagnet by changing the power supplied to the electromagnet in a state where the magnetic force attaching / detaching device is brought into contact with the attraction object while the magnetic force of the attraction body is canceled by the electromagnet. This makes it possible to accurately estimate the attraction force without using an additional sensor. In the attraction force estimation device according to the present invention, the voltage measurement unit may measure only the induced electromotive force generated in the electromagnet as the voltage in the electromagnet.

  The method for estimating the attraction force according to the present invention is characterized in that the electromagnet is based on a time change of a voltage of the electromagnet from a time when a power supply to the electromagnet is changed until a time when a time change of a voltage of the electromagnet converges. It is preferable to obtain an integrated value of the voltage in the above, and estimate the attraction force based on the integrated value. In the attraction force estimating device according to the present invention, the analysis unit may calculate an integral value of a voltage at the electromagnet from a time when a power supply to the electromagnet is changed to a time when a time change of a voltage at the electromagnet converges. It is preferable that the suction force is estimated based on the integrated value.

In this case, as shown in FIG. 1 (a), the input voltage to the electromagnet in a state where canceling the magnetic force of the adsorbent when to V ₀ by the electromagnet, a voltage between the terminals of the electromagnet when in contact with the adsorbed target Becomes V ₀ . From this state, as shown in FIG. 1B, when the supply power to the electromagnet is changed (FIG. 1B shows a state in which the supply power is stopped), the voltage V between the terminals of the electromagnet becomes ,
V = V _in (t) + S × (dB / dt) (1)
It becomes. Here, V _in (t) is the supplied power, S is the cross-sectional area of the coil of the electromagnet, B is the magnetic flux density penetrating the coil of the electromagnet, t is time, and S × (dB / dt) is the induced electromotive force. . Further, if the moment when the supply power is started to be changed is t = 0, V _in (0) = V ₀ .

From equation (1), when the integrated value of the voltage at the electromagnet from the time when the power supplied to the electromagnet is changed to the time when the time change of the voltage at the electromagnet converges is obtained,
∫Vdt = ∫V _in (t) dt + S × B (2)
It becomes. Here, the integral value of V _in (t) _in the first term on the right side does not depend on the magnitude of the attraction force, but the magnetic flux density B depends on the magnitude of the attraction force when attracting to the attraction object. Therefore, the suction force can be estimated by calculating the integral value of the equation (2).

  Further, in this case, the method for estimating the attraction force according to the present invention uses an attraction object having a known attraction force, and previously obtains a relationship between the attraction force of the attraction body and the integral value of the voltage at the electromagnet, Preferably, the suction force is estimated based on the relationship. In the suction force estimating device according to the present invention, the analysis unit is configured to determine a suction force based on a relationship between a suction force of the suction body and an integral value of a voltage in the electromagnet, which is obtained in advance by using a suction target having a known suction force. It is preferable to estimate the attraction force in this manner. In this case, the attraction force can be more accurately estimated. Also, in order to always accurately estimate the attraction force, when the relationship between the attraction force of the adsorbent and the integral value of the voltage at the electromagnet is previously determined, and when the attraction force is newly estimated based on the relationship, the electromagnet is used. It is preferable to always make the same change when changing the power supplied to the power supply.

  The method for estimating the attraction force according to the present invention is such that, after the magnetic force attaching / detaching device is brought into contact with the attraction target, the power supply to the electromagnet is stopped, and the time of the induced electromotive force generated in the electromagnet due to the stop of the power supply The suction force may be estimated based on the change. In the attraction force estimating device according to the present invention, the voltage measuring unit is provided so as to be able to measure an induced electromotive force generated in the electromagnet, and the analyzing unit is configured to stop power supplied to the electromagnet by the power supply unit. The attraction force may be obtained based on a time change of the induced electromotive force generated in the electromagnet. In this case, the first term on the right side of the equations (1) and (2) becomes almost zero, and the voltage at the electromagnet to be measured is almost only the induced electromotive force generated in the electromagnet. The force can be estimated.

  In the method for estimating the attraction force according to the present invention, it is preferable that the attraction body is formed of a permanent magnet, and the magnetic force attachment / detachment device is constituted of a permanent electromagnetic attachment / detachment device. In the attraction force estimating device according to the present invention, it is preferable that the attraction body is made of a permanent magnet, and the magnetic force attaching and detaching device is made of a permanent electromagnetic attaching and detaching device. In this case, the attraction force of a commercially available permanent electromagnetic holder or permanent electromagnetic attachment / detachment device can be accurately estimated. The adsorbent is not limited to a permanent magnet as long as it is attracted by magnetic force, and may be, for example, another magnetic material or another electromagnet.

  According to the present invention, it is possible to provide an attraction force estimation method and an attraction force estimation device that can accurately estimate an attraction force without using an additional sensor.

(A) A cross-sectional view showing the state of the magnetic force of the magnetic force attaching / detaching device when the magnetic force is canceled while the magnetic force is being brought into contact with the object to be attracted. It is sectional drawing which shows the state of the magnetic force of the magnetic force attachment / detachment device when the electric power supply to an electromagnet is stopped. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a block diagram of an attraction force estimating apparatus according to an embodiment of the present invention, and FIG. According to the suction force estimation method and the suction force estimation device of the embodiment of the present invention, (a) when there is no suction target, (b) when suction is performed on a 0.5 mm-thick iron plate, (c) 1 mm thick It is a graph which shows the time change of the voltage in an electromagnet at the time of adsorb | sucking to a 3 mm-thick iron plate when adsorbed on an iron plate. 4 is a graph showing a relationship between an attractive force and an integral value of a voltage in an electromagnet obtained from the graph shown in FIG. 3. FIG. 4 is a graph showing the time change of the voltage of the electromagnet when (a) the multi-copter is mounted and (b) the electro-magnet is not mounted, in the attraction force estimation method and the attraction force estimation device according to the embodiment of the present invention; (C) It is a graph which shows the integral value of the voltage in an electromagnet calculated | required from the graph shown to (a) and (b). (A) A cross-sectional view showing the state of the magnetic force of the magnetic force attaching / detaching device when it is brought into contact with the object to be attracted, and (b) the state of the magnetic force of the magnetic force attaching / detaching device when it is brought into contact with the object to be attracted. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5 show an attraction force estimation method and an attraction force estimation device according to an embodiment of the present invention.
As shown in FIG. 2A, the attraction force estimating device 10 according to the embodiment of the present invention includes a magnetic force attaching / detaching device 11, a power supply unit 12, a voltage measuring unit 13, and an analyzing unit 14.

  As shown in FIG. 2B, the magnetic force attaching / detaching device 11 is composed of a permanent electromagnetic attracting device, and an attracting body 11a composed of a permanent magnet that can be attracted to a ferromagnetic material by a magnetic force, and a magnetic force for canceling the magnetic force of the attracting body 11a. , And a magnetic body 11c. The magnetic body 11c is arranged between the attraction body 11a and the electromagnet 11b and inside the coil of the electromagnet 11b, and is further arranged to cover the outer surfaces of the attraction body 11a and the electromagnet 11b.

  The power supply unit 12 includes a power supply 12a connected to the electromagnet 11b, and a control unit 12b connected between the electromagnet 11b and the power supply 12a. The power supply 12a is provided to be able to supply power to the electromagnet 11b. The control unit 12b includes a driver IC, and is configured to be able to control the magnitude and polarity of power supplied from the power supply 12a to the electromagnet 11b.

  The voltage measurement unit 13 is connected between the electromagnet 11b and the power supply 12a, and is capable of measuring a voltage at the electromagnet 11b. Thereby, the voltage measuring unit 13 can measure the voltage applied to the electromagnet 11b and the induced electromotive force generated in the electromagnet 11b. Further, the voltage measuring unit 13 is configured to obtain power for operation from the power supply 12a.

  The analysis unit 14 includes a microcomputer, is connected to the voltage measurement unit 13, and inputs a voltage measured by the voltage measurement unit 13. The analysis unit 14 is configured to obtain the attraction force of the attraction body 11a based on the time change of the voltage at the electromagnet 11b when the power supplied to the electromagnet 11b by the power supply unit 12 is changed.

  The attraction force estimation method according to the embodiment of the present invention is suitably performed by the attraction force estimation device 10. That is, in the method of estimating the attraction force according to the embodiment of the present invention, first, as shown in FIG. 1A, the magnetism is unknown when the magnetic force of the attraction body 11a is canceled by the electromagnet 11b of the magnetic force attaching / detaching device 11. It is brought into contact with the suction target 1. Thereafter, as shown in FIG. 1B, when the supply power to the electromagnet 11b is changed by the control unit 12b (in FIG. 1B, the supply power is stopped), and when the supply power is changed. , The voltage at the electromagnet 11b is measured by the voltage measuring unit 13.

  Next, based on the measured time change of the voltage at the electromagnet 11b, the analysis unit 14 changes the electromagnet from when the power supplied to the electromagnet 11b is changed to when the time change of the voltage at the electromagnet 11b converges. The integrated value of the voltage at 11b is obtained. At this time, the relationship between the attraction force of the attraction body 11a and the integrated value of the voltage at the electromagnet 11b is determined in advance by using the attraction object 1 whose attraction force is known, and is determined based on the relationship. From the integrated value, the adsorbing force of the adsorbent 11a on the adsorption target 1 can be obtained.

  As described above, the method of estimating the attraction force according to the embodiment of the present invention measures the time change of the voltage at the electromagnet 11b from the state in which the attraction object 1 is in contact with the attraction object 1; Measurement can be performed without being affected by the above. For this reason, the obtained relationship between the voltage and the attraction force of the electromagnet 11b does not depend on the relative speed between the magnetic force attaching / detaching device 11 and the suction target 1, and the attraction force is accurately determined based only on the time change of the voltage at the electromagnet 11b. Can be estimated. Further, the attraction force can be obtained only by measuring the voltage at the electromagnet 11b, and there is no need to use an additional sensor.

  Since the suction force can be obtained at the time of suction to the suction target 1, for example, when lifting the suction target 1, it is determined whether the suction force is sufficient to support the suction target 1 before lifting. be able to. Further, for example, when adsorbing the object 1 to be fixed, it is possible to determine whether or not the adsorbent 11a is sufficient to support the weight of the object adsorbed to the object 1. Thus, it is possible to prevent unintentional desorption from the suction target 1, damage to the suction target 1 due to dropping or dropping from the suction target 1.

  The relationship between the attraction force and the integral value of the voltage at the electromagnet 11b was determined by the attraction force estimation method and the attraction force estimation device 10 according to the embodiment of the present invention. An iron plate having a different thickness and a known suction force was used as the suction target 1, and a commercially available permanent electromagnetic holder was used as the magnetic force attaching / detaching device 11. As the iron plate of the adsorption target 1, three types of iron plates having a thickness and an adsorption force of 0.5 mm and 12.9 N, 1 mm and 31.1 N, 3 mm and 49.2 N, respectively, were used. Further, when changing the power supply to the electromagnet 11b by the control unit 12b, the power supply was stopped. For this reason, the voltage at the electromagnet 11b to be measured is substantially only the induced electromotive force generated in the electromagnet 11b.

  FIGS. 3B to 3D show the results of measuring the voltage of the electromagnet 11b for each of the suction targets 1. FIG. In FIGS. 3B to 3D, the moment when the power supply to the electromagnet 11b is stopped is set to 0 second. FIG. 3A also shows a result when there is no suction target 1 (adsorption force 0 N) for comparison. As shown in FIGS. 3B to 3D, it is confirmed that the induced electromotive force is generated after the power supply to the electromagnet 11b is stopped, and the induced electromotive force is reduced with time and becomes zero. Was done. It was also confirmed that the time required for the induced electromotive force to become zero becomes longer as the attraction force increases. This indicates that there is a correlation between the adsorption force and the induced electromotive force.

Based on the measurement result of FIG. 3, the voltage at the electromagnet 11b from the moment when the supply of power to the electromagnet 11b is stopped to the time when the time change of the voltage at the electromagnet 11b converges, that is, until the time when the induced electromotive force becomes zero. (Induced electromotive force) was calculated, and the result is shown in FIG. As shown in FIG. 4, it was confirmed that there was a positive correlation between the attraction force and the integrated value of the voltage at the electromagnet 11b. When a straight line is applied to this relationship by the method of least squares,
^{_{I V = 0.0016F + 0.0031 (R}} 2 = 0.9078)
It becomes. Here, the I _V integral value of the voltage, F is attracting force, R ² is the square of the correlation coefficient.

  By obtaining the relationship shown in FIG. 4 in advance, it is possible to calculate the attraction force of the attraction body 11a from the integral value of the voltage at the electromagnet 11b obtained at the time of attraction to the attraction target 1, based on the relationship. it can. Accordingly, it is possible to determine whether or not the suction force is sufficient to support the object to be adsorbed on the adsorption target 1 by the adsorbent 11a or the adsorption target 1. Further, since the attraction force varies depending on the thickness of the attraction target 1, if the material of the attraction target 1 is known, the thickness of the attraction target 1 can also be estimated from the determined attraction force.

  The attraction force estimating device 10 was mounted on a multicopter, and was attached to the iron plate of the attraction target 1 from below, the voltage at the electromagnet 11b was measured, and the integrated value was obtained. The iron plate used was a 3 mm-thick iron plate. Further, when changing the power supply to the electromagnet 11b, the power supply was stopped. The voltage measurement in the electromagnet 11b was performed ten times, and the average voltage measurement result is shown in FIG. For comparison, FIG. 5B shows the measurement results of the voltage when not mounted on the multicopter. FIG. 5B is the same as FIG. 3D. FIG. 5C shows the integrated value of the voltage at the electromagnet 11b obtained from the measurement results.

  The time change of the voltage of the electromagnet 11b is substantially the same as the graph when the multi-copter is mounted on the multicopter as shown in FIG. 5A and the graph when it is not mounted as shown in FIG. 5B. Was confirmed. Further, as shown in FIG. 5C, it was confirmed that the integrated value of the voltage in the electromagnet 11b was almost the same when the multi-copter was mounted and when it was not mounted. From this, it is possible to use the suction force estimation method and the suction force estimation device 10 according to the embodiment of the present invention mounted on a multicopter, and to accurately estimate the suction force even when mounted on a multicopter. It was confirmed that it was possible.

  The suction force estimating method and the suction force estimating device according to the present invention include, for example, a device for presenting the success or failure of suction to a user, a robot arm having a magnetic force attaching / detaching device at a hand, and autonomously determining the success or failure of suction, It can also be applied to a drone or the like that has a magnetic attachment / detachment device and that can autonomously determine the success or failure of adsorption to allow birds to rest so that they can catch a perch.

DESCRIPTION OF SYMBOLS 10 Attraction force estimation apparatus 11 Magnetic force attachment / detachment apparatus 11a Attraction body 11b Electromagnet 11c Magnetic body 12 Power supply part 12a Power supply 12b Control part 13 Voltage measurement part 14 Analysis part

51 Permanent electromagnetic holder 52 Electromagnet

Claims (10)

A magnetic attachment / detachment device having an adsorber capable of adsorbing to a ferromagnetic material by a magnetic force and an electromagnet capable of generating a magnetic force for canceling the magnetic force of the adsorbent is provided in a state where the magnetic force of the adsorbent is canceled by the electromagnet. After contacting the magnet, the power supplied to the electromagnet is changed to cause the attraction object to adsorb the adsorbent, and the attraction by the adsorbent is performed based on a time change of the voltage at the electromagnet due to the change in the supplied power. A method for estimating the attraction force by estimating the attraction force to an object without using an additional sensor for obtaining the attraction force.   On the basis of the time change of the voltage at the electromagnet, an integrated value of the voltage at the electromagnet is obtained from the time when the power supply to the electromagnet is changed to the time when the time change of the voltage at the electromagnet converges, 2. The method according to claim 1, wherein the attraction force is estimated based on a value.   Using a suction object having a known suction force, a relationship between a suction force of the suction body and an integral value of a voltage in the electromagnet is obtained in advance, and the suction force is estimated based on the relationship. The method for estimating an attraction force according to claim 2.   After the magnetic force attaching / detaching device is brought into contact with the object to be attracted, the supply power to the electromagnet is stopped, and the attraction force is estimated based on a time change of the induced electromotive force generated in the electromagnet due to the stop of the supply power. The method according to any one of claims 1 to 3, wherein the suction force is estimated.   The attracting force estimating method according to any one of claims 1 to 4, wherein the attracting body is made of a permanent magnet, and the magnetic force attaching / detaching device is made of a permanent electromagnetic attaching / detaching device. A magnetic force attaching / detaching device having an adsorber capable of adsorbing to a ferromagnetic material by a magnetic force, and an electromagnet capable of generating a magnetic force for canceling the magnetic force of the adsorbent,
A power supply unit provided to be able to supply power to the electromagnet;
A voltage measuring unit provided so as to be able to measure the voltage at the electromagnet,
An analysis unit that performs analysis based on the voltage measured by the voltage measurement unit,
The power supply unit is capable of changing power supplied to the electromagnet,
The analysis unit is configured to obtain an attraction force of the attraction body based on a time change of a voltage at the electromagnet when the power supplied to the electromagnet by the power supply unit is changed ,
An attraction force estimation device configured to estimate the attraction force without using an additional sensor for obtaining the attraction force.   The analysis unit obtains an integrated value of the voltage at the electromagnet from a time when the power supplied to the electromagnet is changed to a time when a time change of the voltage at the electromagnet converges, and based on the integrated value, the attraction is performed. 7. The suction force estimating device according to claim 6, wherein the device is configured to estimate a force.   The analysis unit estimates the attraction force based on a relationship between an attraction force of the attraction body and an integral value of a voltage at the electromagnet, which is obtained in advance using an attraction object having a known attraction force. The suction force estimation device according to claim 7, wherein The voltage measurement unit is provided so as to be able to measure an induced electromotive force generated in the electromagnet,
The said analysis part calculates | requires the said attraction force based on the time change of the induced electromotive force which generate | occur | produces in the said electromagnet when the electric power supply to the said electromagnet by the said power supply part is stopped. The attraction force estimating device according to any one of the above. 10. The attraction force estimating device according to claim 6, wherein the attraction body is made of a permanent magnet, and the magnetic force attaching and detaching device is made of a permanent electromagnetic attaching and detaching device.