JP5439086B2 - Moving mechanism, microscope, optimum driving parameter extracting method, and program - Google Patents

Description

  The present invention relates to a moving mechanism including an ultrasonic motor.

Ultrasonic motors have attracted attention as actuators that can replace electromagnetic motors because they have advantages such as being small and highly responsive and not requiring energization when stopped.
As an example of an ultrasonic motor, Patent Document 1 proposes a rectangular parallelepiped ultrasonic motor composed of a laminated piezoelectric body having two types of electrodes. In this ultrasonic motor, by applying alternating wave signals (bending signal and longitudinal signal) having different phases to two types of electrodes, the two driving elements, which are constituent members of the ultrasonic motor, rotate, and the mating member is moved. By moving like a kick, the counterpart member is moved relative to the ultrasonic motor.

  By the way, the ultrasonic motor obtains the vibration amplitude using its own resonance frequency. This resonance frequency may fluctuate due to the effects of assembly errors during assembly of the ultrasonic motor. Even after the assembly of the ultrasonic motor, the resonance frequency fluctuates due to changes in ambient temperature, changes in the contact state with the driven body, the degree of load, and wear of the sliding parts due to long-term use. May end up. Therefore, even if a plurality of ultrasonic motors having the same configuration are driven using the same drive parameters (for example, the same drive frequency and drive phase difference), the resonance frequency is shifted due to the effects of assembly errors or the like. In the case of a sonic motor, stable drive control becomes difficult and efficient drive cannot be performed. Even after assembly, if the ambient temperature changes depending on the usage environment, or if the ultrasonic motor (sliding part, etc.) is worn due to the degree of load or long-term driving, the resonance frequency will shift. Similar problems can occur.

  Therefore, various proposals have been made to solve such problems. For example, in Patent Document 2, stable high-efficiency driving is performed by using an ultrasonic motor vibration detection signal to control the output signal so that the phase difference between the output signal and the detection signal is constant (optimal phase difference). A method for achieving the above has been proposed. As another method, for example, in Patent Document 3, in preparation for the case where the resonance frequency shifts, the drive frequency to be output is always swept, and the detection signal is fed back to drive only the vicinity of the frequency where high-efficiency operation is recognized. As a result, a method has been proposed in which high-efficiency driving is always attempted.

JP 2008-136318 A JP 2008-160913 A Japanese Patent Laid-Open No. 2007-336752

  However, in the method proposed in Patent Document 2, the optimum correlation between the output signal to the ultrasonic motor and the detection signal must be known, and this optimum correlation is not known. When it is clear or when individual differences are large, a problem that it is difficult to use may arise.

  Further, in the method proposed in Patent Document 3, when the ultrasonic motor is placed in a stable environment and the resonance frequency changes rarely, the sweep of the driving frequency slightly improves the efficiency of the ultrasonic motor. Therefore, it is difficult to control at a constant speed, and there may be a problem that the constant speed of the ultrasonic motor drive and the positioning performance are adversely affected.

  In view of the above circumstances, the present invention provides a moving mechanism, a microscope, an optimum drive parameter extraction method, and a program capable of easily setting optimum drive parameters of an ultrasonic motor that operates stably and reliably. Objective.

In order to achieve the above object, a moving mechanism according to a first aspect of the present invention includes a fixed base, a movable body supported to be movable with respect to the fixed base, and the fixed base and the movable body relative to each other. An ultrasonic motor to be moved, a displacement detection means for detecting a relative movement amount between the fixed base and the movable body, and a relative movement amount detected by the displacement detection means are inputted, and a drive signal is sent to the ultrasonic motor. Control means for outputting, wherein the control means includes optimum drive parameter extraction means for extracting an optimum drive parameter of a drive signal to be output to the ultrasonic motor, and the optimum drive parameter extraction means is the ultrasonic motor. The drive parameter of the drive signal to be output is set, the drive signal is output to the ultrasonic motor, and the relative movement amount of the fixed base and the movable body due to the output of the drive signal is determined by the displacement detection. Obtained from unit, processing iterations while changing the drive parameters that extracts the optimum driving parameters based on the relative movement amount obtained from the displacement detector, the greater during operation of the optimum drive parameter extracting means The drive signal output to the sonic motor is a burst waveform signal having a predetermined number of waveforms .

  The moving mechanism according to a second aspect of the present invention is the moving mechanism according to the first aspect, wherein the optimum drive parameter extracting means outputs a drive signal at the set drive parameter to the ultrasonic motor and outputs the drive signal. The process of acquiring the relative movement amount of the fixed base and the movable body from the displacement detection means is repeated a plurality of times for a set of drive parameters, and the relative is acquired a plurality of times for the set of drive parameters. An average value of the movement amount is obtained, and the optimum driving parameter is extracted based on the average value.

  In the moving mechanism according to the third aspect of the present invention, in the first or second aspect, the driving signal output from the control means to the ultrasonic motor is two driving signals, and the driving parameter is the two driving parameters. The optimum drive parameter extracting means includes a first drive parameter that remains as the set of drive parameters and a set of the drive parameters. And a second drive parameter that differs only in phase difference by 180 °, and outputs a drive signal at the set drive parameter to the ultrasonic motor, and the relative movement between the fixed base and the movable body by the output of the drive signal. The process of acquiring the amount from the displacement detection means is repeated a plurality of times for the first drive parameter relating to the set of drive parameters, and the set of drive parameters. The second driving parameter related to the first driving parameter is repeated a plurality of times, and an average value of the relative movement amounts acquired a plurality of times for the first driving parameter is obtained as a first average value, and the second driving parameter is obtained. An average value of the relative movement amounts acquired a plurality of times is obtained as a second average value, an absolute value of a difference between the first average value and the second average value is acquired as an evaluation value, and the evaluation It is characterized in that a set of driving parameters when the value becomes maximum is obtained.

  A moving mechanism according to a fourth aspect of the present invention includes a fixed base, a movable body supported so as to be movable with respect to the fixed base, an ultrasonic motor that relatively moves the fixed base and the movable body, Control means for receiving a vibration detection signal indicating a vibration state from the ultrasonic motor and outputting a drive signal to the ultrasonic motor; and the control means detects the vibration detection signal; Optimal drive parameter extraction means for extracting an optimal drive parameter of the drive signal output to the ultrasonic motor, and the optimal drive parameter extraction means sets the drive parameter of the drive signal output to the ultrasonic motor, The process of outputting the drive signal to the ultrasonic motor, and detecting the vibration detection signal from the ultrasonic motor by the output of the drive signal by the signal detection unit. Repeatedly while changing the dynamic parameters, extracts the optimal driving parameter based on the signal amplitude of the detected vibration detection signal by the signal detecting means, characterized in that.

  The moving mechanism according to a fifth aspect of the present invention is the moving mechanism according to the fourth aspect, wherein the optimum drive parameter extracting means outputs a drive signal at the set drive parameter to the ultrasonic motor and outputs the drive signal. The process of detecting the vibration detection signal from the ultrasonic motor by the signal detecting means is repeated a plurality of times for a set of drive parameters, and the vibration detection signal detected a plurality of times for the set of drive parameters. An average value of the signal amplitude is obtained, and the optimum driving parameter is extracted based on the average value.

  In the moving mechanism according to a sixth aspect of the present invention, in the fourth or fifth aspect, the drive signal output from the control means to the ultrasonic motor is two drive signals, and the drive parameter is the two drive parameters. The optimum drive parameter extracting means includes a first drive parameter that remains as the set of drive parameters and a set of the drive parameters. And a second drive parameter having a phase difference that is 180 ° different from each other, a drive signal at the set drive parameter is output to the ultrasonic motor, and a vibration detection signal from the ultrasonic motor based on the output of the drive signal is output to the ultrasonic motor. The process of detecting by the signal detection means is repeated a plurality of times for the first drive parameter relating to the set of drive parameters and the set of drive parameters. The second drive parameter related to the first drive parameter is repeated a plurality of times, and the average value of the signal amplitude of the vibration detection signal detected a plurality of times for the first drive parameter is obtained as the first average value and the second An average value of signal amplitudes of vibration detection signals detected a plurality of times for the driving parameter is obtained as a second average value, and a sum of the first average value and the second average value is obtained as an evaluation value. A set of driving parameters when the evaluation value is maximized is obtained.

The movement mechanism according to a seventh aspect of the present invention is the movement mechanism according to any one of the fourth to sixth aspects, wherein the drive signal output to the ultrasonic motor during the operation of the optimum drive parameter extraction means is a predetermined number. The number of waveforms is a burst waveform signal.

  The moving mechanism according to an eighth aspect of the present invention is the moving mechanism according to the third or sixth aspect, wherein the driving signal of the first driving parameter is output to the ultrasonic motor, and the driving of the second driving parameter is performed. Outputting a signal to the ultrasonic motor is performed alternately.

  The movement mechanism according to a ninth aspect of the present invention is the movement mechanism according to any one of the first to eighth aspects, wherein the control means operates the optimum drive parameter extraction means when the movement mechanism is activated. It is characterized by that.

  The movement mechanism according to a tenth aspect of the present invention is the movement mechanism according to any one of the first to ninth aspects, wherein the control means is the relative movement amount acquired from the displacement detection means or the vibration detected by the signal detection means. When it is determined that the drive parameter of the drive signal output to the ultrasonic motor is not appropriate based on the signal amplitude of the detection signal, the optimum drive parameter extracting means is operated.

  In the movement mechanism according to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the control means causes the optimum drive parameter extraction means to operate a plurality of times after the movement mechanism is activated. In this case, the drive parameter change range is a range including the optimum drive parameter extracted during the previous operation and is narrower than the drive parameter change range during the normal operation, and the optimum drive parameter extraction unit is operated. It is characterized by that.

  The movement mechanism according to a twelfth aspect of the present invention is the movement mechanism according to any one of the first to eleventh aspects, wherein the operation of the optimum drive parameter extraction means is within a movable range of the movable body relative to the fixed base. It is performed in a limited range of positions.

  The movement mechanism according to a thirteenth aspect of the present invention is the movement mechanism according to any one of the first to twelfth aspects, wherein the relative movement amount or the signal acquired from the displacement detection means during the operation of the optimum drive parameter extraction means. The signal amplitude of the vibration detection signal detected by the detection unit is stored in a storage unit included in the control unit.

  The moving mechanism according to a fourteenth aspect of the present invention is the moving mechanism according to the thirteenth aspect, wherein there are two or more types of drive parameters to be changed during the operation of the optimum drive parameter extracting means, and the optimum drive parameter extracting means When the process is repeated while changing only the first type change target drive parameter and fixing the other type change target drive parameter during the operation, the relative movement amount acquired from the displacement detection unit or The first type of change target drive parameter when it is determined that the signal amplitude of the vibration detection signal detected by the signal detection unit is the largest is the control type by the control unit together with the other type of change target drive parameter. It is stored in the storage means provided.

  The moving mechanism according to a fifteenth aspect of the present invention is the moving mechanism according to the fourteenth aspect, wherein the optimum drive parameter extracting means repeats the process for all combinations of drive parameters to be changed, and then detects the displacement. A second type of change target drive parameter obtained by adding an offset when it is determined that the relative movement amount acquired from the means or the signal amplitude of the vibration detection signal detected by the signal detection means is maximized. A first type corresponding to the first optimum drive parameter from among the first type of change target drive parameters stored in the storage means included in the control means. The change target drive parameter is selected and an offset is added to the first change target drive parameter to obtain the second optimum drive parameter. And over data, characterized in that.

  The present invention is not limited to the moving mechanism, and can be configured as a microscope including the moving mechanism, an optimum driving parameter extracting method in the moving mechanism, and a program in the moving mechanism.

  According to the present invention, the optimum drive parameter of the ultrasonic motor that operates stably and reliably can be easily set, so that the moving mechanism can always perform an efficient operation.

It is a perspective view which shows typically the whole structure of the moving mechanism which concerns on Example 1 of this invention. (a) is a partial top view of the moving mechanism, and (b) is a side view of (a). (a) is a top view of the ultrasonic motor, and (b) is an AA ′ cross-sectional view of (a). It is a figure which shows typically an example of the drive signal which a control apparatus outputs to an ultrasonic motor (vibration body) at the time of a drive. It is a figure which shows the highest level process flow which concerns on the optimal drive parameter automatic extraction function. It is a figure which shows the processing flow which acquires the maximum displacement parameter of S1. It is a figure which shows the processing flow which acquires the maximum displacement phase difference phmax (f) of S14 based on Example 1. FIG. It is a figure which shows the process flow which acquires the evaluation value dav of the drive displacement of S24 based on Example 1. FIG. It is a figure which shows the processing flow which acquires the maximum displacement phase difference phmax (f) of S14 based on Example 2. FIG. It is a figure which shows the processing flow which acquires evaluation value dav of the detection signal amplitude of S41 based on Example 2. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view schematically showing an overall configuration of a moving mechanism according to Embodiment 1 of the present invention. 2 (a) is a partial top view of the moving mechanism, and FIG. 2 (b) is a side view of FIG. 2 (a). FIG. 4A includes a partial perspective view of the moving mechanism.

The moving mechanism according to the present embodiment is, for example, a moving mechanism used as an electric stage (an electric stage for a microscope) included in a microscope.
In the moving mechanism according to the present embodiment shown in FIGS. 1 and 2 (a) and 2 (b), a guide (hereinafter referred to as "guide 2") is formed on the fixed base 1 by a ball circulation type guide rail 2a and a guide block 2b. ") Is installed. The guide 2 is composed of two guide blocks 2b and one guide rail 2a as shown in FIG. 2 (a). The guide rail 2a is fixed to the fixed base 1, and the guide block 2b is a movable body. A certain moving body 3 is fixed. Below the moving body 3, two side members 4 are fixed in parallel to the guide rail 2a, in contact with the guide block 2b, and symmetrically with the guide rail 2a interposed therebetween.

The moving body 3 is supported integrally with the guide block 2b and the side surface member 4 so as to be movable in one axial direction with respect to the fixed base 1.
One of the side members 4 is provided with a sliding member 5 made of a hard material such as ceramic. The ultrasonic motor 6 is fixed to the fixed base 1 so as to contact and press the sliding member 5. Here, the ultrasonic motor 6 is an ultrasonic actuator such as a standing wave ultrasonic motor that moves the moving body 3 and the fixed base 1 relative to each other, and uses a bending vibration and a longitudinal vibration to drive the driven body. And an ultrasonic vibration body (hereinafter simply referred to as “vibration body”) 12 which is a rectangular parallelepiped-shaped vibrator that generates elliptical vibration at the contact position.

  A scale 7 is provided on the other side surface of the movable body 3 where the sliding member 5 is provided, and an encoder 8 is disposed at a position where the pattern of the scale 7 can be detected. It is fixed. Here, the encoder 8 is a displacement sensor (an example of a displacement detection unit) that detects a relative movement amount between the moving body 3 and the fixed base 1 and detects a relative positional relationship between the moving body 3 and the fixed base 1. .

  A control device (an example of control means) 9 that acquires position information from the encoder 8 and drives the ultrasonic motor 6 based on this position information is connected to the encoder 8 and the ultrasonic motor 6 via signal lines. Has been. That is, the control device 9 receives the relative movement amount detected by the encoder 8 and outputs a drive signal to the ultrasonic motor 6.

  In the above configuration, it is desirable that the arrangement interval of the guide blocks 2b is equal to or greater than the maximum movement amount of the moving body 3. By setting such an arrangement interval, the pressing position of the ultrasonic motor 6 can be kept within the arrangement interval of the guide block 2b even if the moving body 3 moves.

3A is a top view of the ultrasonic motor 6, and FIG. 3B is a cross-sectional view taken along line AA ′ of FIG.
In the ultrasonic motor 6 shown in FIGS. 4A and 4B, the holding member 11 is a holding mechanism that holds the vibrating body 12 with respect to the fixed base 1, and is made of a metal material such as aluminum. ing. Further, the holding member 11 has a thin plate spring portion 14 (portion indicated by hatching in FIG. 1A) formed by providing a notch hole portion 13 by wire electric discharge machining or the like. A thick portion 14a that does not act as a spring is formed in the center of the thin plate spring portion 14, and the thick portion 14a and the vibrating body 12 are bonded to each other with a high hardness adhesive such as a ceramic adhesive. At this time, the thin leaf spring portion 14 and the vibrating body 12 are configured to be provided close to each other in parallel. Further, the bonding position of the vibrating body 12 is near the center of the bonding surface of the vibrating body 12.

  In the vibrating body 12, two protrusions 15 (15 a and 15 b) that are driver elements are provided on the surface opposite to the surface to which the thick portion 14 a of the holding member 11 is bonded. The protrusion 15 is made of, for example, a material such as polyacetal containing reinforcing fibers, a material made of a resin having a relatively small friction coefficient, or a material such as ceramic. The holding member 11 is fixed to the fixing base 1 with screws through fixing screw holes 16 (16a, 16b) in a state where both of the protrusions 15 are in contact with the sliding member 5. At this time, it is desirable that the pressing force to the moving body 3 side is in the vicinity of zero in a state in which there is almost no deflection of the thin leaf spring portion 14. In FIG. 1, the fixing screw holes 16 and screws for fixing the holding member 11 to the fixing base 1 are omitted.

  In addition, the holding member 11 is formed with a female screw. Specifically, as shown in FIG. 3B, the thick portion 14a can be pressed by screwing a plunger 17 having a male screw formed on the outer periphery. ing. Although not shown, a coil spring is built in the plunger 17, and a pressing force is generated when the tip member 17a is pushed. For this reason, the pressing force according to the movement amount of the tip member 17a of the plunger 17 is loaded on the thick portion 14a. At this time, the vibrating body 12 is also pressed against the sliding member 5 together with the protrusion 15.

FIG. 4 is a diagram schematically illustrating an example of a drive signal output from the control device 9 to the ultrasonic motor 6 (vibrating body 12) during driving.
As shown in the figure, the vibrating body 12 is a laminated piezoelectric body in which a plurality of plate-like piezoelectric bodies each having a bending vibration electrode 21 (21a, 21b, 21c, 21d) and a longitudinal vibration electrode 22 are laminated. Become. The control device 9 can move the moving body 3 by applying a longitudinal vibration signal and a bending vibration signal having the same frequency and different phases to the longitudinal vibration electrode 22 and the bending vibration electrode 21, respectively. For example, by applying a longitudinal vibration signal which is a sine wave signal to the longitudinal vibration electrode 22 and applying a bending vibration signal which is a sine wave signal whose phase is 90 ° different from that of the longitudinal vibration signal to the bending vibration electrode 21, The moving body 3 can be moved. At this time, the projection 15 is vibrated so as to draw the locus of an ellipse (see the dotted line in the figure) indicated by the arrow in the figure, and the vertical direction of the force generated when the projection 15 contacts the sliding member 6. The frictional force is reduced by the component, and the sliding member 6 (moving body 3) is moved by the force of the horizontal component. In the figure, the sign “+” or “−” of the bending vibration electrode 21 and the longitudinal vibration electrode 22 indicates the polarization direction of the piezoelectric body of the electrode portion.

  By the way, the longitudinal vibration signal and the bending vibration signal output from the control device 9 are determined by setting drive parameters such as frequency, phase difference, voltage (current), and number of waveforms of both signals. Therefore, in order to move the moving body 3 efficiently and stably, it is necessary to set the voltage and the number of waveforms above a certain value and the optimum frequency and phase difference as drive parameters. Therefore, at least the optimum frequency and phase difference must be known. Under the condition that the parts are uniform and there is no assembly error, it may be possible to use the design value or the value obtained once as the optimum frequency and phase difference. Most do not hold. In addition, even after the values are set once as the optimal frequency and phase difference, the optimal frequency and phase difference may vary due to changes in the usage environment (ambient temperature, etc.) and wear of sliding parts due to long-term use, etc. It may fluctuate.

  Therefore, the moving mechanism according to the present embodiment has a function of automatically extracting optimum driving parameters (including at least a frequency and a phase difference) (hereinafter referred to as an optimum driving parameter automatic extracting function). It is configured so that the optimum drive parameter can be easily obtained in the state configured as a mechanism.

  This function can be automatically executed or can be executed in accordance with an instruction from the user. In the case of automatic execution, for example, the actual movement amount of the moving body 3 with respect to the signal given to the ultrasonic motor 6 is acquired based on the detection signal from the encoder 8 and is set at that time from the movement amount. When the control device 9 determines that the driving parameter is not appropriate for the resonance frequency of the ultrasonic motor 6 at that time, the function can be automatically executed. In this case, the determination is made based on, for example, a comparison between the acquired movement amount and a corresponding threshold value. Alternatively, for example, the function can be automatically executed according to time such as every predetermined period or every predetermined total usage period. Alternatively, it can be automatically executed when the moving mechanism is activated. Moreover, when performing according to the instruction | indication from a user, the function can be performed according to the user operating the operation part with which the control apparatus 9 was equipped, for example.

The optimum drive parameter automatic extraction function will be described in detail below.
FIG. 5 is a diagram showing the highest level processing flow related to the optimum drive parameter automatic extraction function. This processing flow is performed when a CPU included in the control device 9 reads and executes a control program stored in a memory (for example, a storage unit such as a ROM) that is also included in the control device 9. Accordingly, the control device 9 includes optimum drive parameter automatic extraction means for performing processing related to the optimum drive parameter automatic extraction function as means realized by the CPU reading and executing the control program. You can also.

  As shown in the figure, in this processing flow, first, in step (hereinafter simply referred to as “S”) 1, the drive frequency fmax when the maximum evaluation value dmax_a (described later in detail) is obtained as the maximum displacement parameter. Then, the drive phase difference phmax (f) when the maximum evaluation value dmax (f) (details will be described later) at each drive frequency f is obtained. The detailed processing content of S1 will be described later with reference to FIG.

  In S2, the offset frequency foffset is added to the drive frequency fmax acquired in S1, and this is set as the optimum drive frequency fop. Here, the reason why the optimum drive frequency fop is obtained by adding the offset frequency foffset to the drive frequency fmax acquired in S1 is that the moving mechanism according to the present embodiment requires particularly precise positioning such as an electric stage for a microscope. When the device is used as an apparatus, the drive frequency fmax acquired in S1 cannot be said to be the optimum drive frequency fop by experiment, and the offset frequency foffset is, for example, about 1 kHz (or less than 1 kHz, for example). This is because the result of obtaining good drive characteristics when the voltage is low or when the number of small waveforms is obtained by setting the optimum drive frequency fop as a value added with the above is obtained. As described above, this processing flow is assumed to be used as a device that requires precise positioning, but for example, it is not assumed to be used as a device that requires such precise positioning. If so, the drive frequency fmax acquired in S1 can be set as the optimum drive frequency fop as it is.

  Note that if the optimum drive frequency fop falls outside the search frequency range described later as a result of adding the offset frequency foffset in S2, the offset frequency foffset is not added. Therefore, only in such a case, the drive frequency fmax acquired in S1 becomes the optimum drive frequency fop as it is.

In S3, the drive phase difference phmax (fop) corresponding to the optimum drive frequency fop set in S2 is selected from the drive phase difference phmax (f) acquired in S1.
In S4, the offset phase difference phoffset is added to the drive phase difference phmax (fop) selected in S3, and this is set as the optimum drive phase difference phop. Here, the reason why the optimum drive phase difference phop is obtained by adding the offset phase difference phoffset to the drive phase difference phmax (fop) selected in S3 is the same reason as described in S2. Therefore, here, for example, if it is not assumed that the apparatus is used as a device that requires precise positioning, the drive phase difference phmax (fop) selected in S3 is set as the optimum drive phase difference phop as it is. It is also possible to configure.

By executing the processing flow shown in FIG. 5, the optimum drive frequency fop and the optimum drive phase difference phop are automatically extracted and set as optimum drive parameters.
FIG. 6 is a diagram showing a processing flow for obtaining the maximum displacement parameter in S1.

  As shown in the figure, in this processing flow, first, in S11, the moving body 3 is moved to a position determined in advance as an origin, and a start frequency fstart and an end frequency fend that define a search frequency range are set. To do.

  In S11, to move the moving body 3 to a position that is determined in advance as an origin is equivalent to moving the moving body 3 to a position where an optimum drive parameter is acquired. The reason for moving the moving body 3 to such a position is that the resonance frequency may differ depending on the contact position between the protrusion 15 and the sliding member 5. In such a case, the actual behavior of the ultrasonic motor 6 may be different. Because it will be different. Accordingly, the movement of the moving body 3 to the origin is also an operation for determining a reference position in order to accurately perform automatic extraction of the optimum drive parameter. Also, by setting the most frequently used position as the origin and determining the optimum drive parameter at the position of the origin, it is possible to always expect a good operation.

  In S11, the start frequency fstart and the end frequency fend that define the search frequency range may be empirically determined values, or only the start frequency fstart may be determined and the optimum end frequency fend The determination may be made based on feedback of a processing result in a part of processing related to the drive parameter automatic extraction function. For example, when a large evaluation value dav is obtained in the process (S24 in FIG. 7) for obtaining an evaluation value dav of driving displacement described later, a peripheral including the frequency when the evaluation value dav is obtained is obtained. It is also possible to set the frequency range as a search frequency range. Alternatively, it is possible to determine the end frequency fend according to the obtained evaluation value dav. Alternatively, when an evaluation value dav greater than a certain value is obtained, a search frequency range can be set at that time.

In S12, the start frequency fstart set in S11 is set as the drive frequency f.
In S13, it is determined whether or not the drive frequency f is equal to or higher than the end frequency fend set in S11. If the determination result is No, the process proceeds to S14.

  In S14, the maximum displacement phase difference at the driving frequency f (the driving phase difference when the maximum evaluation value dmax (f) is obtained at the driving frequency f) phmax (f) is acquired. The detailed processing content of S14 will be described later with reference to FIG.

In S15, the maximum displacement phase difference phmax (f) acquired in S14 is held in a memory (for example, a storage unit such as a RAM) provided in the control device 9.
In S16, a frequency obtained by adding a frequency to be a search step (hereinafter referred to as “search step frequency”) fstep to the drive frequency f is set as a new drive frequency f. As a result, the drive frequency f is changed. After S16, the process returns to S13.

  Thereafter, the processes of S14 to S16 are repeatedly performed until the determination result of S13 is Yes, that is, until the drive frequency f becomes equal to or higher than the end frequency fend. When the determination result in S13 is Yes, the processing flow shown in FIG. 6 is returned, and the maximum displacement phase difference phmax (f) at each driving frequency f held in S15 is used as the maximum displacement parameter. And the driving frequency fmax when the maximum evaluation value dmax_a held in S25 of FIG. 7 described later is obtained is returned.

  In S16 described above, the search step frequency fstep can be set to an arbitrary fixed value, or the search step frequency fstep is theoretically reduced within a range close to the resonance frequency. The search step frequency fstep can be a non-linear function. In the processing flow shown in FIG. 6, first, a rough search is performed by increasing the search step frequency fstep, and then a peripheral including the drive frequency fmax when the maximum evaluation value dmax_a is obtained by the rough search. It is also possible to configure such that the frequency range is searched again by reducing the search step frequency fstep. Alternatively, on the basis of feedback of the evaluation value dav, the search step frequency fstep may be reduced in the direction in which the drive frequency fmax when the maximum evaluation value dmax_a is obtained is predicted to exist. Is possible.

FIG. 7 is a diagram showing a processing flow for obtaining the maximum displacement phase difference phmax (f) in S14.
As shown in the figure, in this processing flow, first, in S21, a start phase difference phstart and an end phase difference phend that define a search phase difference range are set.

  In S21, the start phase difference phstart and the end phase difference phend that define the search phase difference range are empirically determined values, similar to the start frequency fstart and end frequency fend that define the search frequency range in S11. Alternatively, only the start phase difference phstart may be determined, and the end phase difference phend may be determined based on a process result feedback in a part of the process related to the optimum drive parameter automatic extraction function. Good. For example, when a large evaluation value dav is obtained in the process (S24) of obtaining an evaluation value dav of driving displacement described later, a peripheral phase difference including the phase difference when the evaluation value dav is obtained. It is also possible to set the range as a search phase difference range. Alternatively, the end phase difference phend can be determined according to the obtained evaluation value dav. Alternatively, when an evaluation value dav greater than a certain value is obtained, the search phase difference range can be set at that time.

In S22, the start phase difference phstart set in S21 is set as the drive phase difference ph.
In S23, it is determined whether or not the drive phase difference ph is equal to or larger than the end phase difference phend set in S21. Here, if the determination result is No, the process proceeds to S24.

In S24, an evaluation value dav of the drive displacement at the drive frequency f and the drive phase difference ph is acquired. The detailed processing content of S24 will be described later with reference to FIG.
In S25, if the evaluation value dav acquired in S24 is larger than the maximum evaluation value dmax (f) at the driving frequency f obtained up to this point, the evaluation value dav acquired in S24 is used as a new driving frequency. The maximum evaluation value dmax (f) at f and the driving phase difference ph at this time point are set as the maximum displacement phase difference phmax (f) at the driving frequency f up to this point, and these are stored in the memory (for example, the control device 9) (Memory means such as RAM). If the evaluation value dav acquired in S24 is larger than the maximum evaluation value dmax_a obtained up to this time, the evaluation value dav acquired in S24 is set as a new maximum evaluation value dmax_a, and at this time Is the drive frequency fmax when the maximum evaluation value dav up to this point is obtained, and these are also held in a memory (for example, storage means such as a RAM) provided in the control device 9.

  In S26, a value obtained by adding a phase difference (hereinafter referred to as “search step phase difference”) phstep as a search step to the drive phase difference ph is set as a new drive phase difference ph. As a result, the drive phase difference ph is changed. After S26, the process returns to S23.

  Thereafter, the processes of S24 to S26 are repeated until the determination result of S23 is Yes, that is, until the drive phase difference ph is equal to or greater than the end phase difference phend. When the determination result in S23 is Yes, the process flow shown in FIG. 7 is returned, and the maximum displacement phase difference phmax (f) held in S25 is returned.

  In S26 described above, the search step phase difference phstep can be set to an arbitrary fixed value, similarly to the search step frequency fstep in S16 described above, or theoretically within a range close to the resonance frequency. In, the search step phase difference phstep can be a non-linear function, such as reducing the search step phase difference phstep. In the processing flow shown in FIG. 7, first, a rough search is performed by increasing the search step phase difference phstep, and then the drive phase difference phmax (fmax (f) when the maximum evaluation value dmax_a is obtained by the rough search. ) Including the surrounding phase difference range may be searched again by reducing the search step phase difference phstep. Alternatively, on the basis of the feedback of the evaluation value dav, the search step phase difference phstep is reduced when the driving phase difference is predicted to exist when the maximum evaluation value dmax_a is obtained. Is also possible.

FIG. 8 is a diagram showing a processing flow for obtaining the drive displacement evaluation value dav in S24.
In this processing flow, it is assumed that the drive displacement of the moving body 3 obtained by driving the ultrasonic motor 6 may fluctuate for each drive even if all the drive parameters are the same. As a measure for reducing variations in drive displacement, as will be described in detail later, driving by the first driving parameter and driving by the second driving parameter are alternately performed a plurality of times, and driving by the first driving parameter is performed. Based on the obtained average value of the plurality of driving displacements and the average value of the plurality of driving displacements obtained by the driving with the second driving parameter, the evaluation value dav of the driving displacement is obtained.

  As shown in the figure, in this processing flow, first, in S31, the acquisition number nav of drive displacement is set. Note that this number of acquisitions defines how many times the driving using the first driving parameter and the driving using the second driving parameter, which will be described later, are alternately performed.

In S32, the number of times n is set to 1. This process is a process for initializing the number n.
In S33, it is determined whether the number n is larger than the acquisition number nav determined in S31. If the determination result is No, the process proceeds to S34.

  In S34, the drive frequency f and drive phase difference ph at this time, the maximum voltage that can be output, and a certain number of waveforms (here, 500 are set as an example) are set as the first drive parameters. The longitudinal vibration signal and the bending vibration signal based on the setting are output from the control device 9 to the ultrasonic motor 6 as a burst waveform. In other words, the frequency and phase difference are set to the driving frequency f and the driving phase difference ph at this point, the voltage is the maximum voltage that can be output, and the longitudinal vibration signal and bending vibration signal with 500 waveforms are output as burst waveforms. To do. Thereby, the + direction burst output which moves the mobile body 3 to + direction (forward direction, forward direction) is performed. Here, the maximum voltage and the number of waveforms that can be output are 500 and the number of waveforms and the number of waveforms are one or more combinations of a frequency within the search frequency range and a phase difference within the search phase difference range. Any value can be used as long as the movable body 3 can be moved. However, the voltage and the number of waveforms are constant from the start to the end of execution of the process related to the optimum drive parameter automatic extraction function.

  In S35, based on the positional information from the encoder 8, the driving displacement dp (n) of the moving body 3 by the + direction burst output performed in S34 is obtained, and this is stored in a memory (for example, a memory such as a RAM) provided in the control device 9 Means). Since this driving displacement uses a burst output for driving, the driving of the ultrasonic motor 6 stops after the burst output with respect to the position information from the encoder 8 before the burst output, and the moving body 3 moves. Is obtained by the control device 9 processing the position information from the encoder 8 when is stopped. Further, the driving displacement dp (n) obtained here becomes a positive value when the moving direction of the moving body 3 by the positive direction burst output performed in S34 is a positive direction, and this is a negative direction. If it is, it becomes a negative value.

  In S36, as the second drive parameter, the phase difference is set to a phase difference shifted by 180 ° with respect to the drive phase difference ph at this time, and other than the phase difference is set to the first drive parameter set in S34. The same drive parameter is set, and the longitudinal vibration signal and the bending vibration signal based on this setting are output from the control device 9 to the ultrasonic motor 6 as a burst waveform. As a result, a -direction burst output for moving the moving body 3 in the -direction (negative direction, reverse direction) is performed. The phase difference set as the second drive parameter is, for example, −90 ° (= 90 ° −180 °) when the drive phase difference ph at this time is 90 °.

  In S37, the driving displacement dm (n) of the moving body 3 based on the -direction burst output performed in S36 is obtained based on the position information from the encoder 8 as in S35 described above, and this is provided in the control device 9. It is held in a memory (for example, storage means such as a RAM). The driving displacement dm (n) obtained here becomes a positive value when the moving direction of the moving body 3 by the negative direction burst output performed in S36 is the + direction, as in S35. When is in the-direction, the value is-.

In S38, a value obtained by adding 1 to the number n is set as a new number n.
In S39, when the position of the moving body 3 is shifted by a predetermined amount or more (for example, ± 1 mm or more) with respect to the position determined as the origin in advance, the moving body 3 is moved to the origin. As described above, in S39, a threshold value is provided in order to suppress the movement amount variation due to the position of the moving body 3, and the moving body 3 is moved at approximately the same place near the origin.

  After S39, the process returns to S33. Thereafter, the above-described processing of S34 to 39 is repeated until the determination result of S33 is Yes, that is, until the number n is greater than the acquisition number nav.

  Note that the moving direction of the moving body 3 due to the + direction burst output in S34 and the moving direction of the moving body 3 due to the − direction burst output in S36 are not necessarily opposite to each other. When the value of the drive parameter is close to the value of the optimum drive parameter at which a large drive displacement is obtained, it is approximately in the opposite direction. The reason why the burst output of S34 and S36 is alternately repeated is that the amount of movement of the moving body 3 by driving the ultrasonic motor 6 is confirmed by an experiment, and only in one direction due to the burst output of S34 or S36. This is because when the continuous movement is performed, the friction state between the protrusion 15 and the sliding member 5 changes unevenly, and the movement amount may change unevenly. Further, when the movement by the burst output of S34 and S36 is alternately repeated with respect to the continuous movement only in one direction, the moving range of the moving body 3 can be reduced. Therefore, in this processing flow, by alternately repeating the movement by the burst output of S34 and S36, the fluctuation of the moving amount due to the position of the moving body 3 can be suppressed, and the moving body 3 moves to the origin in S39. Since the number of times can be reduced, the processing time can be shortened.

If the determination result in step S33 is Yes, the process proceeds to step S40.
In S40, an evaluation value dav of driving displacement is calculated. Specifically, the average value of the remaining drive displacements dp (n) excluding the drive displacement dp (1) among the drive displacements dp (n) held in S35 (the average of dp (2) to dp (nav)) Value) and the average value of the remaining drive displacements dm (n) excluding the drive displacement dm (1) among the drive displacements dm (n) held in S37 (average value of dm (2) to dm (nav) The absolute value of this difference is calculated as the drive displacement evaluation value dav, and this is held in a memory (for example, storage means such as a RAM) provided in the control device 9. The reason why the drive displacements dp (1) and dm (1) acquired at the first time are excluded is that the drive acquired at the first time after the first drive parameter is changed or after continuous operation of burst output. This is because the displacement may become unstable.

When S40 ends, the process flow shown in FIG. 8 is returned, and the evaluation value dav of the drive displacement held by S40 is returned.
As described above, in this processing flow, as in S36, the phase difference at the time of the -direction burst output is shifted from the phase difference at the time of the -direction burst output by 180 ° as theoretically. For this reason, when evaluating the drive displacement by the drive parameter, the drive displacement obtained under the drive parameter (first drive parameter) and the drive parameter in which only the phase difference is shifted by 180 ° with respect to the drive parameter. The drive displacement obtained under (second drive parameter) is a value that increases in the opposite direction (value that increases in the + and − directions), using the drive displacement evaluation value dav calculated in S40. To be able to evaluate. In such an evaluation, the drive displacement evaluation value dav calculated in S40 is divided into the drive displacement evaluation value dav_p by the + direction burst output and the drive displacement evaluation value dav_m by the − direction burst output, and the like. In the processing flow, it is possible to individually search for the phase difference that maximizes the drive displacement for each direction.

  The optimum drive frequency fop and the optimum drive phase difference phop obtained by executing the process related to the optimum drive parameter automatic extraction function as described above are set as the drive parameter frequency and phase difference, and this optimum drive frequency fop and optimum drive are set. By outputting the longitudinal vibration signal and the bending vibration signal having the phase difference phop to the ultrasonic motor 6, the moving body 3 can be reliably moved. The obtained optimum drive frequency fop and optimum drive phase difference phop are drive parameters that the moving amount of the moving body 3 is substantially maximized, and have a voltage equal to or greater than a certain value and a certain number of waveforms. The moving body 3 can be moved by outputting the longitudinal vibration signal and the bending vibration signal. Here, in the case of controlling the moving amount and moving speed of the moving body 3, in the longitudinal vibration signal and the bending vibration signal, one or more of the voltage, current, and number of waveforms that are substantially proportional to the moving amount may be changed. Alternatively, the drive frequency and the drive phase difference may be changed to a frequency and a phase difference slightly deviated from the optimum drive frequency fop and the optimum drive phase difference phop. Alternatively, each of the drive parameters may be changed in combination.

  As described above, according to the moving mechanism according to the present embodiment, it is possible to easily obtain and set the optimum drive frequency and drive phase difference as drive parameters by executing the above-described optimum drive parameter automatic extraction function. In addition, since the optimum drive parameter automatic extraction function is executed in the moving mechanism after assembly, the resonance frequency fluctuates due to the effects of assembly errors during assembly of the ultrasonic motor, When the resonance frequency fluctuates due to changes in the ambient temperature after assembly of the sonic motor, changes in the contact state with the driven body, the degree of load, and wear of sliding parts due to long-term use, etc. Even so, by executing the function, the optimum drive frequency and drive phase difference corresponding to the changed resonance frequency can be easily obtained and set. In addition, by outputting a longitudinal vibration signal and a bending vibration signal corresponding to the set drive frequency and drive phase difference to the ultrasonic motor, stable drive control and efficient drive can be performed, so the moving mechanism can be It can be operated efficiently.

  The moving mechanism according to the second embodiment of the present invention is partly different in configuration and operation from the moving mechanism according to the first embodiment. Therefore, in the description of the moving mechanism according to the present embodiment, the different points will be mainly described.

  In the moving mechanism according to the present embodiment, the longitudinal vibration electrode 22 is used as the longitudinal vibration detection electrode in some of the plurality of plate-like piezoelectric bodies constituting the vibrating body 12. Therefore, a signal line for applying a longitudinal vibration signal is not connected to the longitudinal vibration electrode 22 used as the longitudinal vibration detection electrode, but instead, a signal line for detecting the longitudinal vibration is connected to the control device. 9 is connected. Further, in the control device 9, the longitudinal vibration detection for detecting the longitudinal vibration detection signal from the longitudinal vibration electrode 22 used as the longitudinal vibration detection electrode via the signal line for detecting the longitudinal vibration. A circuit is further provided. Other configurations are the same as those of the moving mechanism according to the first embodiment.

  In the moving mechanism according to the present embodiment having such a configuration, the longitudinal vibration detection circuit does not acquire the evaluation value of the drive displacement as the evaluation value dav acquired during the process related to the optimum drive parameter automatic extraction function. The evaluation value of the signal amplitude (hereinafter simply referred to as “detection signal amplitude”) of the longitudinal vibration detection signal detected by the above is acquired.

  That is, in the process related to the optimum drive parameter automatic extraction function according to the present embodiment, the process of acquiring the drive displacement evaluation value dav in S24 in the process flow of acquiring the maximum displacement phase difference phmax (f) shown in FIG. As shown in FIG. 9, the process is replaced with the process of obtaining the evaluation value dav of the detection signal amplitude in S41. In S41, the evaluation value dav of the detection signal amplitude at the drive frequency f and the drive phase difference ph is acquired.

  FIG. 10 is a diagram showing a processing flow for obtaining the evaluation value dav of the detection signal amplitude in S41. This figure corresponds to the processing flow for obtaining the drive displacement evaluation value dav shown in FIG.

  As shown in FIG. 10, in this processing flow, first, in S51, a detection signal amplitude acquisition number nav is set. Note that this number of acquisitions defines how many times the driving using the first driving parameter and the driving using the second driving parameter, which will be described later, are alternately performed.

In S52, the number of times n is set to 1. This process is a process for initializing the number n.
In S53, it is determined whether the number n is larger than the acquisition number nav determined in S51. Here, if the determination result is No, the process proceeds to S54.

  In S54, the driving frequency f and the driving phase difference ph at this time and the voltage and the number of waveforms that do not move the moving body 3 are set as the first driving parameters, and the longitudinal vibration signal and the bending based on this setting are set. The vibration signal is output as a burst waveform from the control device 9 to the ultrasonic motor 6. That is, the longitudinal vibration signal and the bending vibration signal having the frequency and the phase difference as the driving frequency f and the driving phase difference ph at this time, and the voltage and the number of waveforms as the voltage and the number of waveforms at which the moving body 3 does not move And output as a burst waveform. As a result, a + direction burst output is performed to move the moving body 3 in the + direction. Also in this embodiment, the set voltage and the number of waveforms are constant from the start to the end of the processing related to the optimum drive parameter automatic extraction function.

  In S55, the vertical vibration detection circuit provided in the control device 9 detects the vertical vibration detection signal generated in the positive direction burst output performed in S54, and acquires the detected signal amplitude ap (n). Is held in a memory (for example, a storage means such as a RAM).

  In S56, as the second drive parameter, the phase difference is set to a phase difference shifted by 180 ° with respect to the drive phase difference ph at this time point, and the phase difference other than the phase difference is set to the first drive parameter set in S54. The same drive parameter is set, and the longitudinal vibration signal and the bending vibration signal based on this setting are output from the control device 9 to the ultrasonic motor 6 as a burst waveform. As a result, a -direction burst output for moving the moving body 3 in the -direction is performed.

  In S57, in the same manner as in S55 described above, the longitudinal vibration detection circuit provided in the control device 9 detects the longitudinal vibration detection signal based on the negative direction burst output, acquires the detected signal amplitude am (n), and controls it. The data is held in a memory (for example, a storage unit such as a RAM) included in the device 9.

In S58, a value obtained by adding 1 to the number n is set as a new number n, and the process returns to S53.
Thereafter, the processes of S54 to S58 described above are repeated until the determination result of S53 is Yes, that is, until the number n is greater than the acquisition number nav. If the determination result in S53 is Yes, the process proceeds to S59.

  In S59, an evaluation value dav of the detection signal amplitude is calculated. Specifically, the average value (ap (2) to ap (nav) of the remaining detection signal amplitude ap (n) excluding the detection signal amplitude ap (1) among the detection signal amplitude ap (n) held in S55. ) And the average value (am (2) to am) of the remaining detection signal amplitude am (n) excluding the detection signal amplitude am (1) in the detection signal amplitude am (n) held in S57. (average value of (nav)) is calculated as an evaluation value dav of the detection signal amplitude, and this is held in a memory (for example, storage means such as a RAM) provided in the control device 9. Note that the reason for excluding the detection signal amplitudes ap (1) and am (1) acquired for the first time is the same as in S40 of FIG. 8 after the first drive parameter is changed or after continuous operation of burst output. This is because the detection signal amplitude acquired for the first time may become unstable.

When S59 ends, the process flow shown in FIG. 10 is returned, and the evaluation value dav of the detection signal amplitude held in S59 is returned.
The other processes related to the optimum drive parameter automatic extraction function are the same as the processes related to the optimum drive parameter automatic extraction function according to the first embodiment.

  In the optimum drive parameter automatic extraction function according to the present embodiment, as described above, the detection signal amplitude is obtained instead of the drive displacement, so the process of obtaining the maximum displacement parameter shown in FIG. In S11, it is possible to omit the operation of moving the moving body 3 to the origin.

  Also, the optimum drive parameter automatic extraction function according to the present embodiment can be automatically executed in the same manner as the optimum drive parameter automatic extraction function according to the first embodiment, or can be executed in response to an instruction from the user. it can. However, in the case of automatic execution, for example, from the signal amplitude of the longitudinal vibration detection signal detected by the longitudinal vibration detection circuit provided in the control device 9, the drive parameter set at that time is If the control device 9 determines that the resonance frequency of the ultrasonic motor 6 is not appropriate, the function can be automatically executed. In this case, the determination is made based on, for example, a comparison between the detected signal amplitude of the longitudinal vibration detection signal and a corresponding threshold value.

  As described above, according to the moving mechanism according to the present embodiment, in addition to obtaining the same effect as the moving mechanism according to the first embodiment, the detection signal amplitude is obtained instead of obtaining the drive displacement. During the execution of the process related to the drive parameter automatic extraction function, the moving body 3 does not reciprocate and the movement of the moving body 3 to the origin can be omitted, so that the processing time can be shortened.

  In the moving mechanism according to the present embodiment, the longitudinal vibration electrode 22 of a part of the plate-like piezoelectric body in the vibration body 12 is used as the longitudinal vibration detection electrode, and the signal amplitude of the longitudinal vibration detection signal is acquired and processed. However, instead of this, the bending vibration electrode 21 of a part of the plate-like piezoelectric body in the vibrating body 12 is used as the bending vibration detection electrode, and the signal amplitude of the bending vibration detection signal is acquired. It is also possible to configure so that processing is performed in the same manner. Alternatively, it is possible to combine both of them to acquire the signal amplitudes of both the longitudinal vibration detection signal and the bending vibration detection signal and perform the same processing.

  Further, in the movement mechanism according to the present embodiment, in the process related to the optimum drive parameter automatic extraction function, the process of repeating the operation of acquiring the detection signal amplitude by performing the drive by the burst output is performed, but the continuous drive is simply performed. It is also possible to change the drive parameters sequentially during the continuous drive, acquire the detection signal amplitude each time, and perform the same processing.

  In the movement mechanism according to the present embodiment, in the process related to the optimum drive parameter automatic extraction function, the detection signal amplitude is obtained by driving by the + direction burst output, and the detection signal amplitude is obtained by driving by the − direction burst output. The process of acquiring the detection signal amplitude is performed in the same manner, but the operation of acquiring only the detection signal amplitude by driving only the burst output of either the + direction burst output or the − direction burst output is performed in the same manner. It is also possible to configure to perform processing.

  As described above, the movement mechanism according to the first and second embodiments has been described. However, in the movement mechanism according to each embodiment, when the process related to the optimum drive parameter automatic extraction function is performed a plurality of times after the movement mechanism is activated, The optimum drive frequency and optimum drive phase difference acquired as the optimum drive parameter for the search frequency range, that is, the optimum drive frequency and optimum drive phase difference set as the optimum drive parameter at this time, and the search frequency range and the search phase difference range. It is also possible to determine. In this case, the search frequency range can be set to a range including the optimum drive frequency set at this time and narrower than the normal search frequency range. The range including the optimum drive phase difference set at this time can be set to a range narrower than the normal search phase difference range. As a result, in the process related to the optimum driving parameter automatic extraction function for the second and subsequent times, the search range is narrowed, so that the processing time can be shortened. The reason why such processing is possible is that the optimum drive frequency and optimum drive phase difference acquired as the optimum drive parameters by the execution of the process related to the previous optimum drive parameter automatic extraction function change greatly thereafter. Because there is no.

  Moreover, in the moving mechanism which concerns on each Example, it is also possible to comprise combining the structure and operation | movement of the moving mechanism which concerns on another Example. For example, when the process related to the optimum drive parameter automatic extraction function is performed immediately after the movement mechanism is activated, the process related to the optimum drive parameter automatic extraction function according to the first embodiment is executed, and the user is using the movement mechanism. In the case where the processing related to the optimum drive parameter automatic extraction function is executed when the driving of the ultrasonic motor 6 is temporarily stopped and the moving body 3 is stopped, It is also possible to configure so as to execute the processing related to the optimum drive parameter automatic extraction function according to No. 2. As a result, in the process related to the optimum drive parameter automatic extraction function executed while the user is using the movement mechanism, the processing time is shorter than the process related to the optimum drive parameter automatic extraction function executed immediately after the movement mechanism is activated. Therefore, the time during which the user's work is interrupted can be shortened.

  Further, in the movement mechanism according to each embodiment, in the process related to the optimum drive parameter automatic extraction function, the optimum drive frequency and the optimum drive phase difference are acquired as the optimum drive parameters. It is also possible to configure so as to obtain the optimum value of the number of waveforms.

  In the moving mechanism according to each embodiment, the control device 9 includes a CPU that controls the operation of the entire moving mechanism by executing a control program, a main memory that the CPU uses as a work memory as necessary, a mouse, a keyboard, and the like. An input unit for acquiring various instructions from the user, an interface unit for managing transmission and reception of signals with the ultrasonic motor 6 and the encoder 8, and a hard disk device for storing various programs and data, for example It can also be configured by a computer with a very standard configuration having the auxiliary storage device. In this case, a control program for causing the CPU of the computer to perform processing related to the optimum drive parameter automatic extraction function is created and recorded on a computer-readable recording medium, and the program is read from the recording medium to the computer. It is also possible to execute it by the CPU. As a recording medium from which the recorded control program can be read by a computer, for example, a storage device such as a ROM or a hard disk device provided as an internal or external accessory device in the computer, or a medium driving device provided in the computer is inserted. A portable recording medium such as a flexible disk, MO (magneto-optical disk), CD-ROM, DVD-ROM, or the like from which the control program recorded can be read out can be used. Further, the recording medium may be a storage device provided in a computer system functioning as a program server connected to a computer via a communication line. In this case, a transmission signal obtained by modulating a carrier wave with a data signal representing a control program is transmitted from the program server to a computer through a communication line as a transmission medium, and the computer demodulates the received transmission signal. By replaying the control program, the control program can be executed by the CPU of the computer.

  The present invention has been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Fixing base 2 Guide 3 Moving body 4 Side member 5 Sliding member 6 Ultrasonic motor 7 Scale 8 Encoder 9 Control device 11 Holding member 12 Vibrating body 13 Notch hole portion 14 Thin plate spring portion 15 Protrusion portion 16 Fixing screw hole 17 Plunger 21 Bending vibration electrode 22 Longitudinal vibration electrode

Claims (20)

A fixed base;
A movable body supported to be movable with respect to the fixed base;
An ultrasonic motor for relatively moving the fixed base and the movable body;
Displacement detecting means for detecting a relative movement amount between the fixed base and the movable body;
Control means for inputting a relative movement amount detected by the displacement detection means and outputting a drive signal to the ultrasonic motor;
With
The control means includes optimum drive parameter extraction means for extracting an optimum drive parameter of a drive signal output to the ultrasonic motor,
The optimum drive parameter extracting means sets a drive parameter of a drive signal output to the ultrasonic motor, outputs the drive signal to the ultrasonic motor, and outputs the drive signal to the fixed base and the movable body. of the relative movement amount obtained from the displacement detector, processing iterations while changing the drive parameters that extracts the optimum driving parameters based on the relative movement amount obtained from the displacement detector,
The drive signal output to the ultrasonic motor during the operation of the optimum drive parameter extraction means is a burst waveform signal having a predetermined number of waveforms.
A moving mechanism characterized by that. The optimum drive parameter extraction unit outputs a drive signal at the set drive parameter to the ultrasonic motor, and acquires a relative movement amount between the fixed base and the movable body from the displacement detection unit based on the output of the drive signal. The process is repeated a plurality of times for a set of drive parameters, an average value of relative movement amounts acquired a plurality of times for the set of drive parameters is obtained, and the optimum drive parameter is extracted based on the average value. To
The moving mechanism according to claim 1. The drive signal that the control means outputs to the ultrasonic motor is two drive signals,
The drive parameter includes a phase difference between the two drive signals,
The optimum driving parameter extracting means includes
For a set of drive parameters, a first drive parameter that remains as the set of drive parameters and a second drive parameter that differs in phase difference by 180 ° in the set of drive parameters are provided. ,
A set of driving processes for outputting a driving signal at the set driving parameter to the ultrasonic motor and obtaining a relative movement amount between the fixed base and the movable body from the displacement detecting means by the output of the driving signal. Relative multiple times for the first drive parameter and the second drive parameter for the set of drive parameters and multiple times for the first drive parameter. An average value of movement amounts is obtained as a first average value, an average value of relative movement amounts obtained a plurality of times for the second drive parameter is obtained as a second average value, and the first average value and the Obtain the absolute value of the difference from the second average value as the evaluation value,
Obtaining a set of driving parameters when the evaluation value is maximized;
The moving mechanism according to claim 1 or 2, wherein A fixed base;
A movable body supported to be movable with respect to the fixed base;
An ultrasonic motor for relatively moving the fixed base and the movable body;
Control means for receiving a vibration detection signal indicating a vibration state from the ultrasonic motor and outputting a drive signal to the ultrasonic motor;
With
The control means includes
Signal detection means for detecting the vibration detection signal;
An optimum drive parameter extracting means for extracting an optimum drive parameter of a drive signal output to the ultrasonic motor;
Including
The optimum drive parameter extraction unit sets a drive parameter of a drive signal output to the ultrasonic motor, outputs the drive signal to the ultrasonic motor, and detects vibration from the ultrasonic motor based on the output of the drive signal. The process of detecting a signal by the signal detection unit is repeated while changing the drive parameter, and the optimum drive parameter is extracted based on the signal amplitude of the vibration detection signal detected by the signal detection unit.
A moving mechanism characterized by that. The optimum drive parameter extraction means outputs a drive signal at the set drive parameter to the ultrasonic motor, and detects the vibration detection signal from the ultrasonic motor by the output of the drive signal by the signal detection means. Is repeated a plurality of times for a set of drive parameters, an average value of signal amplitudes of vibration detection signals detected a plurality of times for the set of drive parameters is obtained, and the optimum drive parameters are extracted based on the average value. To
The moving mechanism according to claim 4. The drive signal that the control means outputs to the ultrasonic motor is two drive signals,
The drive parameter includes a phase difference between the two drive signals,
The optimum driving parameter extracting means includes
For a set of drive parameters, a first drive parameter that remains as the set of drive parameters and a second drive parameter that differs in phase difference by 180 ° in the set of drive parameters are provided. ,
A process of outputting a drive signal in the set drive parameter to the ultrasonic motor and detecting a vibration detection signal from the ultrasonic motor by the output of the drive signal by the signal detection unit relates to a set of drive parameters. Repeating a plurality of times for the first driving parameter and a plurality of times for the second driving parameter of the set of driving parameters, the vibration detection signal detected a plurality of times for the first driving parameter. An average value of the signal amplitude is obtained as the first average value, and an average value of the signal amplitude of the vibration detection signal detected a plurality of times with respect to the second drive parameter is obtained as the second average value, and the first average value is obtained. A sum of the value and the second average value is obtained as an evaluation value;
Obtaining a set of driving parameters when the evaluation value is maximized;
The moving mechanism according to claim 4 or 5, wherein The drive signal output to the ultrasonic motor during the operation of the optimum drive parameter extraction means is a burst waveform signal having a predetermined number of waveforms.
The moving mechanism according to any one of claims 4 to 6, wherein Outputting the drive signal of the first drive parameter to the ultrasonic motor and outputting the drive signal of the second drive parameter to the ultrasonic motor are alternately performed.
The moving mechanism according to claim 3 or 6, characterized in that The control means operates the optimum drive parameter extraction means when the moving mechanism is activated.
The moving mechanism according to any one of claims 1 to 8, wherein: The control means determines that the drive parameter of the drive signal output to the ultrasonic motor is not appropriate based on the relative movement amount acquired from the displacement detection means or the signal amplitude of the vibration detection signal detected by the signal detection means. When operating the optimum drive parameter extraction means,
The moving mechanism according to any one of claims 1 to 9, wherein: The control means, when the optimum drive parameter extracting means is operated a plurality of times after the movement mechanism is activated, the change range of the drive parameter is a range including the optimum drive parameter extracted at the previous operation, Operating the optimum drive parameter extraction means as a range narrower than the drive parameter change range during operation;
The moving mechanism according to any one of claims 1 to 10, wherein The operation of the optimum drive parameter extraction means is performed at a limited range of positions within the movable range of the movable body with respect to the fixed base.
The moving mechanism according to any one of claims 1 to 11, wherein: During the operation of the optimum drive parameter extraction unit, the relative movement amount acquired from the displacement detection unit or the signal amplitude of the vibration detection signal detected by the signal detection unit is stored in a storage unit included in the control unit.
The moving mechanism according to any one of claims 1 to 12, wherein There are two or more driving parameters to be changed during the operation of the optimum driving parameter extracting means,
Acquired from the displacement detection means when the process is repeated while only the first type change target drive parameter is changed and the other type change target drive parameter is fixed during the operation of the optimum drive parameter extraction means. The first type of change target drive parameter when it is determined that the relative movement amount or the signal amplitude of the vibration detection signal detected by the signal detection unit is the largest is the other type of change target drive parameter. And stored in the storage means included in the control means,
The moving mechanism according to claim 13. The optimum drive parameter extracting means repeats processing for all combinations of drive parameters to be changed, and then the relative movement amount acquired from the displacement detection means or the vibration detection signal detected by the signal detection means A signal obtained by adding an offset to the second type of drive parameter to be changed when it is determined that the signal amplitude of the signal becomes the largest is stored in the storage unit included in the control unit. The first type of change target drive parameter corresponding to the first optimum drive parameter is selected from the first type of change target drive parameters, and the first change target drive parameter is selected. The offset is added as the second optimum drive parameter.
The moving mechanism according to claim 14.   A microscope comprising the moving mechanism according to any one of claims 1 to 15. A fixed base, a movable body supported so as to be movable with respect to the fixed base, an ultrasonic motor for relatively moving the fixed base and the movable body, and a relative movement amount between the fixed base and the movable body. An optimum drive parameter of the drive signal in a moving mechanism comprising: a displacement detection means for detecting; and a control means for inputting a relative movement amount detected by the displacement detection means and outputting a drive signal to the ultrasonic motor. A method of extracting,
The control means sets the drive parameter of the drive signal output to the ultrasonic motor, outputs the drive signal to the ultrasonic motor, and the relative movement between the fixed base and the movable body by the output of the drive signal The process of acquiring the amount from the displacement detection unit is repeated while changing the drive parameter, and the optimum drive parameter is extracted based on the relative movement amount acquired from the displacement detection unit.
An optimum drive parameter extraction method characterized by the above. A fixed base, a movable body supported so as to be movable relative to the fixed base, an ultrasonic motor that relatively moves the fixed base and the movable body, and a vibration detection signal indicating a vibration state from the ultrasonic motor. A method of extracting an optimum driving parameter of the driving signal in a moving mechanism including a control unit that is input and outputs a driving signal to the ultrasonic motor,
The control means sets a drive parameter of a drive signal output to the ultrasonic motor, outputs the drive signal to the ultrasonic motor, and detects a vibration detection signal from the ultrasonic motor based on the output of the drive signal. Repeating the process of changing the drive parameter, and extracting the optimal drive parameter based on the signal amplitude of the detected vibration detection signal,
An optimum drive parameter extraction method characterized by the above. A fixed base, a movable body supported so as to be movable with respect to the fixed base, an ultrasonic motor for relatively moving the fixed base and the movable body, and a relative movement amount between the fixed base and the movable body. This is executed by a computer of the control means in a movement mechanism comprising a displacement detection means for detecting and a control means for inputting a relative movement amount detected by the displacement detection means and outputting a drive signal to the ultrasonic motor. A program
A drive parameter of a drive signal output to the ultrasonic motor is set, the drive signal is output to the ultrasonic motor, and a relative movement amount between the fixed base and the movable body based on the output of the drive signal is detected as the displacement. A program for causing the computer to realize a function of repeating the process of acquiring from the means while repeating the drive parameter while extracting the optimum drive parameter based on the relative movement amount acquired from the displacement detection means. A fixed base, a movable body supported so as to be movable relative to the fixed base, an ultrasonic motor that relatively moves the fixed base and the movable body, and a vibration detection signal indicating a vibration state from the ultrasonic motor. A program executed by a computer of the control means in a moving mechanism provided with a control means for inputting and outputting a drive signal to the ultrasonic motor,
A process of setting a drive parameter of a drive signal output to the ultrasonic motor, outputting the drive signal to the ultrasonic motor, and detecting a vibration detection signal from the ultrasonic motor based on the output of the drive signal. A program for causing the computer to realize a function of repeatedly extracting the optimum drive parameter based on the detected amplitude of the vibration detection signal while changing the drive parameter.