JP2014101917A - Precise drive unit, and precise drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakage of a plate spring even if a large external force is applied at transportation or the like.SOLUTION: A precise drive unit comprises: a holding mechanism that can switch a movable base (1) to a connected state or separated state with respect to a fixed base (4) by moving the movable base (1) that is supported to a plate spring (3) by using magnets (5, 6) that can make adsorption forces variable by a magnetizing/demagnetizing coil (7); a magnetizing/demagnetizing circuit (9) that applies a current to the coil (7) on the basis of the measurement result of a magnetic sensor (8); a linear motor (2) that moves the movable base according to a command signal; a correction operator (11) that estimates the absorption forces of the magnets from the measurement result of the magnetic sensor (8), calculates a correction command signal when the estimated absorption forces in demagnetized states are not absorption forces of the demagnetized states, and calculates the command signal by adding the correction command signal to a reference command signal; and a drive unit (12) that drives the linear motor on the basis of the command signal.

Description

  The present invention relates to a precision driving device and a precision driving method that require high-precision directivity, such as a satellite or a flying object-mounted device, or a telescope.

  Satellites equipped with telescopes for observing the earth and celestial bodies, flying objects that irradiate objects with lasers, or terrestrial telescopes that observe distant stars require high precision pointing accuracy over the entire operating range. Has been. Therefore, for example, in the pointing axis control of an artificial satellite equipped with a telescope, the accuracy of the operation is high and narrow due to coarse control that covers a large operating range with low accuracy by driving the satellite body and a relatively small precision driving device. The structure which combined the fine control which covers the is employ | adopted (for example, refer nonpatent literature 1).

  In the precision drive device that is the subject of the present invention, high-precision sensors and actuators are used to realize high-precision control. In order to bring out these performances, it is necessary to reduce the friction of the drive unit. For this reason, a leaf spring that is not affected by friction is often used for the drive unit (see, for example, Patent Document 1).

US Patent Application Publication No. 2005/0161578

Development of SOLAR-B satellite onboard image stabilization tracking device, KOMI, Kashiwagi, etc., Japan Aerospace Society Proceedings, vol55 (637), 57-64, 2007

However, the prior art has the following problems.
Of precision drive devices that use leaf springs to eliminate the influence of drive friction, when the actuator size is limited, the required drive range can be operated with limited actuator thrust. To do so, the leaf spring must be softened. However, when the leaf spring becomes soft, there is a problem that the leaf spring is damaged when a large external force is applied during transportation.

  The present invention has been made to solve the above problems, and provides a precision driving device and a precision driving method capable of preventing the leaf spring from being damaged even when a large external force is applied during transportation. The purpose is that.

  The precision drive device according to the present invention couples the movable base to the fixed base by moving the movable base supported by the leaf spring by a magnet whose magnetizing or demagnetizing coil can change the attraction force. A holding mechanism that can be switched to a separated state or a separated state, a magnetic sensor that measures a magnetic flux that is an index of the magnetized state / demagnetized state of the magnet, and a magnet that can be set to a target magnetized state / demagnetized state. In order to make the attractive force variable, the relative distance from the fixed base by moving the movable base according to the command signal and the magnetizing / demagnetizing circuit that applies current to the coil based on the measurement result by the magnetic sensor After applying a current to the coil with the goal of demagnetizing with a linear motor and a magnetizing / demagnetizing circuit, the magnet's attractive force was estimated from the magnetic flux measured by the magnetic sensor If the adhering force is not a demagnetizing attracting force, a linear motor calculates a correction command signal for moving the movable base to a position where the demagnetizing attracting force is obtained, and moves the movable base to a desired position. A correction arithmetic unit that calculates a command signal by adding a reference command signal given from the outside to the correction command signal, and a drive circuit that drives the linear motor based on the command signal calculated by the correction arithmetic unit Are provided.

  In addition, the precision driving method according to the present invention is such that the movable base supported by the leaf spring is moved with respect to the fixed base by moving the movable base supported by the plate spring by a magnet whose magnetizing or demagnetizing force can vary the attraction force. Is a precision driving method used in a precision driving device having a holding mechanism that can be switched to a coupled state or a separated state, and using a magnetic sensor, a magnetic flux serving as an index of the magnetized state / demagnetized state of the magnet is obtained. Magnetic flux measurement step to be measured, and magnetizing / applying current to the coil based on the measurement result of the magnetic flux measurement step in order to make the magnet's attractive force variable so as to achieve the target magnetization / demagnetization state A demagnetizing step and an estimation step for estimating the magnet's attracting force from the magnetic flux measured by the magnetic sensor after applying a current to the coil with the goal of demagnetizing the magnetized / demagnetized step. If the attracting force estimated by the estimation step is not the attracting force in the demagnetized state, demagnetization is performed by a linear motor that can change the relative distance from the fixed base by moving the movable base according to the command signal. Correction amount calculating step for calculating a correction command signal for moving the movable base to a position where the state of the attracting force is obtained, a reference command signal given from the outside for moving the movable base to a desired position, and a correction amount calculation A command signal calculation step for calculating a command signal by adding the correction command signal calculated in the step and a drive step for driving the linear motor based on the command signal calculated in the command signal calculation step are provided. .

  According to the present invention, a movable base supported by a leaf spring can be switched between a coupled base and a separated base with respect to a fixed base by a magnet that can vary the attractive force with a magnet that magnetizes or demagnetizes the movable base. By attaching a holding mechanism to increase the magnet's attractive force during transportation and connecting the movable base to the fixed base, damage to components even when a large external force is applied during transportation, etc. It is possible to obtain a precision driving device and a precision driving method that can prevent the above-described problem.

It is a perspective view which shows the precision drive device in Embodiment 1 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 1 of this invention. It is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 1 of this invention. It is a figure which shows the functional block of the correction | amendment calculating unit in the precision drive device in Embodiment 1 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 2 of this invention. It is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 2 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 3 of this invention. It is a figure which shows the functional block of the correction | amendment arithmetic unit with a learning function in the precision drive device in Embodiment 3 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 4 of this invention. It is a figure which shows the functional block of the direct correction | amendment calculating unit in the precision drive device in Embodiment 4 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 5 of this invention. It is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 5 of this invention. It is sectional drawing which shows the precision drive device at the time of the operation | movement in Embodiment 6 of this invention. It is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 6 of this invention.

  Hereinafter, preferred embodiments of a precision driving device and a precision driving method of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a precision driving device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing the precision drive device during operation according to Embodiment 1 of the present invention.

  As shown in FIGS. 1 and 2, the precision drive device according to the first embodiment includes a movable base 1, a linear motor 2, a linear motion plate spring 3, a fixed base 4, a suction pad 5, a suction pad 6, and a coil. 7, a magnetic sensor 8, a magnetization / demagnetization circuit 9, a correction calculator 11, and a drive circuit 12. Here, the attracting pad 5 and the attracted pad 6 correspond to magnets whose attracting force can be varied by the coil 7 that is magnetized or demagnetized.

  As shown in FIG. 2, the precision driving apparatus according to the first embodiment is entirely surrounded by a fixed base 4. However, in FIG. 1, the fixed base is provided only on the bottom surface to make the structure easy to understand. 4 is shown as a perspective view with a state.

  The movable base 1 and the fixed base 4 are coupled by a linear plate spring 3. The movable base 1 is driven by a linear motor 2. An adsorption pad 5, which is a hard magnetic material, and a coil 7 surrounding the adsorption pad 5 are attached to the movable base 1. On the other hand, the attracted pad 6, which is a soft magnetic material and is attracted to the attracting pad 5, is attached to the fixed base 4.

  A magnetic sensor 8 that measures the magnetic flux of the suction pad 5 is attached in the vicinity of the suction pad 5. The magnetizing / demagnetizing circuit 9 determines a magnetizing / demagnetizing current 91 to be passed through the coil 7 based on a magnetic sensor signal 81 corresponding to the magnetic flux measured by the magnetic sensor 8.

  The correction calculator 11 reads a reference command signal 111 given from the outside in order to move the movable base 1 to a desired position by driving the linear motor 2 and a magnetic sensor signal 81 measured by the magnetic sensor 8. A corrected command signal 116 is generated based on these signals. Details of the operation of the correction calculator 11 will be described later with reference to FIG. Furthermore, the drive circuit 12 takes in the corrected command signal 116 generated by the correction calculator 11 and outputs a drive signal 121 to the linear motor 2.

  FIG. 3 is a cross-sectional view showing the precision drive device during transportation according to Embodiment 1 of the present invention. That is, the movable base 1 is separated from the fixed base 4 during operation as shown in FIG. 2, and the fixed base 4 is transported as shown in FIG. In this state, the movable base 1 is coupled.

  According to the configuration of the first embodiment, if a current is passed through the coil 7 and the suction pad 5 is magnetized, then the suction pad 6 can be moved by the magnetic field of the suction pad 5 without passing a current through the coil 7. Magnetized and an attracting force is generated, the linear plate spring 3 is deformed, and the movable base 1 and the fixed base 4 are coupled. Thereby, even if big external force is applied at the time of conveyance, it can avoid that the direct-acting leaf | plate spring 3 is damaged.

  Conversely, if a magnetizing / demagnetizing current 91 that generates a magnetic field in the opposite direction to the magnetic field of the adsorption pad 5 is passed through the coil 7 and the adsorption pad 5 is demagnetized, then no current flows through the coil 7. The attracted pad 6 that has been magnetized loses its magnetism, and the movable base 1 and the fixed base 4 are separated from each other by the restoring force of the linear motion plate spring 3.

  The magnetizing / demagnetizing circuit 9 measures the magnetic flux of the attracting pad 5 with the magnetic sensor 8 after applying the first magnetizing / demagnetizing current 91 to the coil 7 and the demagnetization is insufficient. The second magnetization / demagnetization current 91 can be applied. The magnetizing / demagnetizing circuit 9 repeats such a re-application operation a plurality of times, and ideally reduces the magnetic flux of the suction pad 5 to zero, thereby increasing the suction force of the suction pad 5 and the suction pad 6. It can be made zero (that is, the adsorption power in the time-out state).

  Accordingly, during operation, the thrust of the linear motor 2 can be used only for the deformation of the leaf spring, which can contribute to lower power consumption. In particular, a remarkable effect can be obtained in a satellite-mounted device in which power consumption restrictions are important.

  Further, according to the configuration of the first embodiment, contamination such as dust at the time of release, which is inevitable, is used to destroy the holding mechanism using explosives that are often used for holding mechanisms such as artificial satellites. There is an effect that can be eliminated. This effect is particularly remarkable in applications where the contamination is fatal in terms of mission such as a telescope.

  FIG. 4 is a diagram showing functional blocks of the correction computing unit 11 in the precision driving device according to Embodiment 1 of the present invention. Actually, it is envisaged that the suction force of the suction pad 5 and the suction pad 6 cannot be reduced to zero in the operating state due to uncertain factors such as restrictions on sensors that can be used and environmental changes.

  Therefore, even in such a case, by using the driving force of the linear motor 2 by the operation of the correction calculator 11, the movable base 1 can be configured so that the suction force of the suction pad 5 and the suction pad 6 becomes equivalent to zero. The required drive accuracy can be realized by moving the.

  Specifically, as shown in FIG. 4, the correction calculator 11 includes an adsorption force estimator 112 and a command converter 114. The attracting force estimator 112 estimates the attracting force between the attracting pad 5 and the attracted pad 6 based on the magnetic sensor signal 81 and outputs the estimated attracting force signal 113. The attracting force estimator 112 estimates the attracting force by, for example, preparing in advance a relationship between the attracting force of the magnetic sensor signal 81, the attracting pad 5 and the attracted pad 6 using a lookup table. Can do.

  Then, the command converter 114 converts the estimated adsorption force signal 113 into a correction signal 115. Thereafter, the correction calculator 11 superimposes the correction signal 115 on the reference command signal 111 and outputs a corrected command signal 116. Such a series of operations achieves the required drive accuracy.

  As described above, according to the first embodiment, the movable base supported by the leaf spring can be coupled to the fixed base by the magnet whose adsorption force can be varied with the magnetizing or demagnetizing coil. It has a mechanism. Then, the magnetization and demagnetization state of the magnet is measured by a magnetic sensor, and the current applied to the coil is controlled so as to achieve the target magnetization or demagnetization state.

  In addition, the linear motor adjusts the position of the movable base by reflecting the suction force that could not be removed by such current control in the drive command value so that the suction force that could not be removed would reduce the accuracy of drive control. By fine adjustment, precise driving is possible.

  By providing such a holding mechanism, it is possible to avoid breakage of the leaf spring even when a large external force is applied by increasing the magnet's attracting force and coupling the movable base and the fixed base during transportation. Can do.

  Furthermore, at the time of operation, the movable base and the fixed base can be separated by reducing or eliminating the magnet's attractive force. As a result, at the time of operation, the thrust of the linear motor can be used only for deformation of the leaf spring, which can contribute to low power consumption, even when the actuator size and applied current are limited, with limited actuator thrust, The required driving range can be operated.

  Furthermore, even when demagnetization cannot be sufficiently performed during operation, the generated attracting force can be compensated and precise driving can be performed. Furthermore, compared with the detonator type which is one of the holding mechanisms in the artificial satellite, this configuration has an extremely excellent effect from the viewpoint of contamination.

  In a holding mechanism using an electromagnet in many prior examples (see, for example, Japanese Patent Laid-Open No. 1-215699), it is necessary to keep a current flowing during holding or separation. On the other hand, in the configuration of the holding mechanism according to the present invention, the attractive force of the magnet is changed by magnetization or demagnetization. For this reason, when changing the attraction force, a current is passed through the coil. However, after the attraction force changes, there is no need to steadily flow an electric current, which has a remarkable effect that it can contribute to lower power consumption.

Embodiment 2. FIG.
In the first embodiment, the case where the suction pad 5 and the coil 7 are attached to the movable base 1 and the suctioned pad 6 is attached to the fixed base 4 has been described. On the other hand, in the second embodiment, a case where the suction pad 5 and the coil 7 are attached to the fixed base 4 and the suctioned pad 6 is attached to the movable base 1 will be described.

  FIG. 5 is a cross-sectional view showing the precision drive device during operation according to Embodiment 2 of the present invention. Moreover, FIG. 6 is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 2 of this invention.

  According to such a configuration of the second embodiment, in addition to the effects of the first embodiment, by attaching the suction pad 5 and the coil 7 that increase in weight to the fixed base 4, The driving object can be reduced in weight. For this reason, there is an effect of improving the driving amount of the movable base 1 or reducing the size of the linear motor 2. Moreover, since the wiring from the movable base 1 which becomes a disturbance factor can be removed, the control accuracy is improved.

  As described above, according to the second embodiment, by adopting a structure in which the suction pad and the coil are provided on the fixed base side, in addition to the effects of the first embodiment, the weight of the movable base is reduced, and the linear motor The control accuracy can be improved by downsizing and eliminating the movable base wiring which causes disturbance.

Embodiment 3 FIG.
In the third embodiment, a method for further improving the control accuracy by providing the linear sensor 10 that measures the relative position of the movable base 1 and the fixed base 4 will be described.

  FIG. 7 is a cross-sectional view showing the precision drive device during operation according to Embodiment 3 of the present invention. In the third embodiment, a linear sensor 10 for measuring the relative position of the movable base 1 and the fixed base 4 is attached to the fixed base 4. Then, the linear sensor signal 101 detected by the linear sensor 10 is taken into a correction calculator 21 with a learning function corresponding to a correction calculator, and a post-learning correction command signal 216 is generated. In addition to the linear sensor signal 101, the reference command signal 111 and the magnetic sensor signal 81 are taken into the correction calculator with learning function 21.

  Next, the function of the correction calculator with learning function 21 will be described in detail with reference to the drawings. FIG. 8 is a diagram showing functional blocks of the correction computing unit with learning function 21 in the precision driving apparatus according to Embodiment 3 of the present invention. Actually, it is conceivable that the error amount is superimposed on the corrected command signal 116 due to an uncertain parameter that varies depending on the environment and posture.

  Therefore, even in such a case, as described above, the learning result based on the relative position of the movable base 1 and the fixed base 4 measured by the linear sensor 10 is used by the function of the correction calculator 21 with a learning function. A large amount of error can be suppressed.

  Specifically, as shown in FIG. 8, the correction calculator with learning function 21 is configured to include an adsorption force estimator 212 with learning function and a command converter 114. Then, the attraction force estimator 212 with a learning function is a magnetic sensor measured by the magnetic sensor 8 based on the linear sensor signal 101 which is a measurement result by the linear sensor 10 and the rigidity of the linear plate spring 3 identified in advance. The learning device updates the correspondence between the signal 81 and the estimated adsorption force.

  The learning function-adsorbing force estimator 212 then uses the learning device to estimate the adsorbing force between the adsorbing pad 5 and the adsorbing pad 6 from the magnetic sensor signal 81 measured by the magnetic sensor 8, and the learning estimated adsorbing force. Output as a signal 213. Note that the adsorption function estimator 212 with a learning function can update a lookup table prepared in advance as described in the first embodiment by using the linear sensor signal 101, for example. .

  Then, the command converter 114 converts the learning estimated adsorption force signal 213 into a learning correction signal 215. Thereafter, the correction calculator with learning function 21 superimposes the learning correction signal 215 on the reference command signal 111 and outputs a learning corrected command signal 216. By such a series of operations, the error amount superimposed on the corrected command signal can be suppressed.

  As described above, according to the third embodiment, in addition to the effect of the second embodiment, the error amount superimposed on the corrected command signal by the uncertain parameter that varies depending on the environment and posture is corrected with the learning function. It can be suppressed by the operation of the arithmetic unit.

  Furthermore, if learning is performed on the correction computing unit with a learning function immediately before the operation and the learning function is stopped during actual operation, the operation time is not required, and only the memory access to the lookup table is used for learning. A corrected command signal can be generated, which is effective in speeding up the control.

Embodiment 4 FIG.
In the fourth embodiment, the linear sensor 10 that measures the relative position of the movable base 1 and the fixed base 4 is provided, so that the suction force between the suction pad and the suction pad is directly determined based on the measurement result of the linear sensor 10. An estimation method will be described.

  FIG. 9 is a cross-sectional view showing the precision drive device during operation according to Embodiment 4 of the present invention. In the fourth embodiment, a linear sensor 10 for measuring the relative position of the movable base 1 and the fixed base 4 is attached to the fixed base 4 as in the third embodiment. Further, in the fourth embodiment, a direct correction calculator 31 is provided instead of the correction calculator with learning function 21 in the previous third embodiment. Note that only the linear sensor signal 101 is taken into the direct correction calculator 31 corresponding to the correction calculator.

  Next, the function of the direct correction calculator 31 will be described in detail with reference to the drawings. FIG. 10 is a diagram showing functional blocks of the direct correction calculator 31 in the precision driving apparatus according to Embodiment 4 of the present invention. Actually, it is conceivable that the error amount is superimposed on the corrected command signal 116 due to an uncertain parameter that varies depending on the environment and posture.

  Therefore, even in such a case, the error as described above can be obtained by using the learning result based on the relative position of the movable base 1 and the fixed base 4 measured by the linear sensor 10 by the action of the direct correction calculator 31. The amount can be suppressed.

  Specifically, as shown in FIG. 10, the direct correction calculator 31 includes a direct attracting force estimator 312 and a command converter 114. The direct attraction force estimator 312 is a product of the linear sensor signal 101 that is the measurement result of the linear sensor 10 and the rigidity K of the linear plate spring 3 identified in advance, between the suction pad 5 and the suction pad 6. The attracting force is estimated and directly output as an estimated attracting force signal 313.

  Then, the command converter 114 converts the direct estimated adsorption force signal 313 into a direct correction signal 315. Thereafter, the direct correction calculator 31 superimposes the direct correction signal 315 on the reference command signal 111 and outputs a direct corrected command signal 316. By such a series of operations, the error amount superimposed on the corrected command signal can be suppressed.

  As described above, according to the fourth embodiment, in addition to the effect of the second embodiment, by measuring the suction force directly from the linear sensor signal, it is possible to use uncertain parameters that vary depending on the environment and posture. The amount of error superimposed on the corrected command signal can be suppressed.

  Furthermore, there is an advantage that wiring can be omitted by adopting a configuration in which the magnetic sensor signal measured by the magnetic sensor is not directly used in the correction calculator.

Embodiment 5 FIG.
In the first to fourth embodiments, the case where the direct acting leaf spring 3 is used as the leaf spring has been described. On the other hand, in the fifth embodiment, a case where the rotating leaf spring 13 is used as a leaf spring will be described.

  FIG. 11 is a cross-sectional view showing the precision drive device during operation according to Embodiment 5 of the present invention. Moreover, FIG. 12 is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 5 of this invention. In the fifth embodiment, a rotating leaf spring 13 is attached instead of the direct acting leaf spring 3. Further, the attracting pad 5, the coil 7, the attracted pad 6, the magnetic sensor 8, and the magnetizing / demagnetizing circuit 9 are attached to both sides of the movable base 1 with the rotary plate spring 13 as the center.

  According to the configuration of the fifth embodiment as described above, if an electric current is passed through the coil 7 and the adsorption pad 5 is magnetized, then the magnetic field of the adsorption pad 5 can be applied without passing an electric current through the coil 7. The suction pad 6 is magnetized to generate a suction force, the rotary leaf spring 13 is deformed, and the movable base 1 and the fixed base 4 are coupled.

  On the other hand, if a magnetizing / demagnetizing current 91 that generates a magnetic field in the opposite direction to the magnetic field of the adsorption pad 5 is passed through the coil 7 and the adsorption pad 5 is demagnetized, the magnetizing is performed without passing an electric current through the coil 7 thereafter. The attracted pad 6 that has been lost loses its magnetism, and the movable base 1 and the fixed base 4 are separated by the restoring force of the rotating leaf spring 13.

  As described above, according to the fifth embodiment, even in a precision driving device in which the drive of the movable base is not a direct motion but is changed to a rotation, by applying a rotating leaf spring instead of a direct acting leaf spring, An equivalent effect obtained in the fourth embodiment can be obtained.

Embodiment 6 FIG.
In the sixth embodiment, the suction pad 5 and the sucked pad 6 are coupled using the parallel leaf spring 14 in the configuration using the rotating leaf spring 13 as in the fifth embodiment. A coupling method different from the fifth embodiment will be described.

  FIG. 13 is a cross-sectional view showing a precision drive device during operation according to Embodiment 6 of the present invention. Moreover, FIG. 14 is sectional drawing which shows the precision drive device at the time of conveyance in Embodiment 6 of this invention. In the sixth embodiment, the attracted pad 6 is attached to the end of the movable base 1, and the parallel leaf springs 14 made of a soft magnetic material are attached to the upper and lower end faces of the attracted pad 5.

  Here, the parallel leaf spring 14, the suction pad 5, the coil 7, the attracted pad 6, the magnetic sensor 8, and the magnetizing / demagnetizing circuit 9 are attached to both sides of the movable base 1 around the rotating leaf spring 13. It has been. In addition, one end 141 of the parallel leaf spring 14 is magnetically and mechanically coupled to the suction pad 5.

  According to the configuration of the sixth embodiment as described above, if a current is passed through the coil 7 and the adsorption pad 5 is magnetized, then the magnetic field of the adsorption pad 5 does not cause a current to flow even if no current flows through the coil 7. The parallel leaf spring 14 made of a magnetic material is magnetized.

  Further, since the free end 142 of the parallel leaf spring 14 is also magnetized, the attracted pad 6 is magnetized by this magnetic field, the parallel leaf spring 14 is deformed, and the free end 142 and the attracted pad of the parallel leaf spring 14 are deformed. 6 are combined.

  On the other hand, if a magnetizing / demagnetizing current 91 that generates a magnetic field in the opposite direction to the magnetic field of the adsorption pad 5 is passed through the coil 7 and the adsorption pad 5 is demagnetized, the magnetizing is performed without passing an electric current through the coil 7 thereafter. The parallel plate spring 14 and the attracted pad 6 that have been made lose magnetism, and the movable base 1 and the fixed base 4 are separated by the restoring force of the parallel plate spring 14.

  As described above, according to the sixth embodiment, even in a precision driving device in which the driving of the movable base is not a direct motion but is changed to a rotation, by applying a rotating leaf spring instead of a direct acting leaf spring, An equivalent effect obtained in the fourth embodiment can be obtained. Furthermore, in comparison with the previous embodiment 5, the amount of deformation of the rotating leaf spring during transportation can be reduced by adopting the configuration of the present embodiment 6, so that the elastic deformation region of the rotating leaf spring is small. Is effective.

  DESCRIPTION OF SYMBOLS 1 Movable base, 2 Linear motor, 3 Linear motion leaf | plate spring, 4 Fixed base, 5 Adsorption pad, 6 Adsorbed pad, 7 Coil, 8 Magnetic sensor, 9 Magnetization / demagnetization circuit, 10 Linear sensor, 11 Correction calculator , 112 Adsorption power estimator, 114 Command converter, 12 Drive circuit, 13 Rotating leaf spring, 14 Parallel leaf spring, 21 Correction calculator with learning function (correction calculator), 212 Adsorption force estimator with learning function (adsorption force) Estimator), 31 direct correction calculator (correction calculator), 312 direct adsorption force estimator (adsorption force estimator).

Claims (8)

By moving the movable base supported by the leaf spring with a magnet that can change the attractive force with a coil that is magnetized or demagnetized, the movable base can be switched to a coupled state or a separated state with respect to the fixed base. Holding mechanism to
A magnetic sensor for measuring a magnetic flux serving as an index of the magnetized state / demagnetized state of the magnet;
A magnetizing / demagnetizing circuit for applying a current to the coil based on a measurement result by the magnetic sensor in order to make the attraction force of the magnet variable so as to be a target magnetized state / demagnetized state; ,
A linear motor that makes the relative distance from the fixed base variable by moving the movable base according to a command signal;
After applying a current to the coil for the purpose of setting the demagnetization state by the magnetization / demagnetization circuit, the adsorption force of the magnet is estimated from the magnetic flux measured by the magnetic sensor, and the estimated adsorption If the force is not the attracting force in the demagnetized state, a correction command signal for moving the movable base to a position where the attracting force in the demagnetized state is obtained by the linear motor is calculated, and the movable base is A correction calculator for calculating the command signal by adding a reference command signal given from the outside to move to a position and the calculated correction command signal;
A precision drive device comprising: a drive circuit that drives the linear motor based on the command signal calculated by the correction calculator. The precision drive device according to claim 1,
The magnet is composed of a suction pad provided on the movable base and a suction pad provided on the fixed base,
The leaf spring is composed of a direct acting leaf spring,
The coil is wound around the suction pad to magnetize or demagnetize the suction pad;
The magnetic sensor is a precision driving device that measures the magnetic flux of the suction pad. The precision drive device according to claim 1,
The magnet is composed of a suction pad provided on the fixed base and a suction pad provided on the movable base,
The leaf spring is composed of a direct acting leaf spring,
The coil is wound around the suction pad to magnetize or demagnetize the suction pad;
The magnetic sensor is a precision driving device that measures the magnetic flux of the suction pad. In the precision drive device according to claim 2 or 3,
A linear sensor for measuring the relative position of the movable base and the fixed base;
The correction calculator calculates a correspondence relationship between the magnetic flux measured by the magnetic sensor and the estimated attracting force based on the measurement result of the linear sensor and the rigidity of the linear motion leaf spring identified in advance. A precision driving device that has a learning device to be updated and uses the learning device to estimate an attracting force between the attracting pad and the attracted pad from the magnetic flux measured by the magnetic sensor. In the precision drive device according to claim 2 or 3,
A linear sensor for measuring the relative position of the movable base and the fixed base;
Instead of estimating the attractive force between the attracted pad and the attracted pad from the magnetic flux measured by the magnetic sensor, the correction computing unit calculates the linear sensor and the measurement result by the linear sensor and the previously identified linear motion plate A precision driving device that directly estimates the suction force between the suction pad and the suction pad based on the rigidity of the spring. The precision drive device according to claim 1,
A linear sensor for measuring the relative position of the movable base and the fixed base;
The magnet is composed of a suction pad provided on the fixed base and a suction pad provided on the movable base,
The leaf spring is composed of a rotating leaf spring that couples the movable base and the fixed base,
The coil is wound around the suction pad to magnetize or demagnetize the suction pad;
The magnetic sensor measures the magnetic flux of the suction pad,
Instead of estimating the attractive force between the attracted pad and the attracted pad from the magnetic flux measured by the magnetic sensor, the correction calculator calculates the result of the linear sensor and the rotary leaf spring identified in advance. A precision driving device that directly estimates the suction force between the suction pad and the suction pad based on the rigidity of the suction pad. In the precision drive device of Claim 6,
The suction pad is attached to an end of the movable base,
A soft magnetic material is provided on the upper and lower end faces of the suction pad, and one end is magnetically and mechanically coupled to the suction pad, and the other end is obtained by magnetizing the suction pad. A precision driving device further comprising: a parallel leaf spring having a free end coupled to the sucked pad. By moving the movable base supported by the leaf spring with a magnet that can change the attractive force with a coil that is magnetized or demagnetized, the movable base can be switched to a coupled state or a separated state with respect to the fixed base. A precision driving method used in a precision driving device having a holding mechanism to perform,
A magnetic flux measuring step for measuring a magnetic flux as an index of the magnetized state / demagnetized state of the magnet using a magnetic sensor;
Magnetization / demagnetization step of applying current to the coil based on the measurement result of the magnetic flux measurement step in order to make the attraction force of the magnet variable so as to be a target magnetization state / demagnetization state. When,
An estimation step of estimating an attracting force of the magnet from the magnetic flux measured by the magnetic sensor after applying a current to the coil for the purpose of setting the demagnetization state by the magnetization / demagnetization step;
When the attracting force estimated by the estimating step is not the attracting force in the demagnetized state, a linear motor that varies the relative distance from the fixed base by moving the movable base according to a command signal, A correction amount calculating step for calculating a correction command signal for moving the movable base to a position where the demagnetizing state becomes the attractive force;
A command signal calculating step for calculating the command signal by adding a reference command signal given from the outside to move the movable base to a desired position and the correction command signal calculated in the correction amount calculating step; ,
And a driving step of driving the linear motor based on the command signal calculated in the command signal calculating step.

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