JP2990836B2 - Driving method of ultrasonic motor - Google Patents
Driving method of ultrasonic motorInfo
- Publication number
- JP2990836B2 JP2990836B2 JP3090378A JP9037891A JP2990836B2 JP 2990836 B2 JP2990836 B2 JP 2990836B2 JP 3090378 A JP3090378 A JP 3090378A JP 9037891 A JP9037891 A JP 9037891A JP 2990836 B2 JP2990836 B2 JP 2990836B2
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- JP
- Japan
- Prior art keywords
- drive
- moving body
- driving
- voltages
- ultrasonic motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、圧電セラミック等の圧
電体を用いて振動体に弾性進行波を励振することにより
駆動力を発生する超音波モータの駆動方法に関するもの
であり、超音 波モータの高速反転動作を実現する駆動方
法に関するものである。 The present invention relates to a relates to a driving method of the ultrasonic motor that generates driving force by exciting the acoustic traveling wave in the vibrator using a piezoelectric element such as piezoelectric ceramics
, And the driving direction to realize a high-speed reverse operation of the ultrasonic wave motor
It is about the law.
【０００２】[0002]
【従来の技術】以下、図面を参照しながら超音波モータ
とその駆動方法の従来技術について説明を行う。図７
は、円環形超音波モータの一部切り欠き斜視図であり、
円環形の弾性基板１の円環面の一方に圧電体として円環
形圧電セラミック２を貼合せて振動体３を構成してい
る。４は耐磨耗性材料の摩擦材、５は弾性体であり、互
いに貼合せられて移動体６を構成している。移動体６は
摩擦材４を介して図示していない加圧手段により振動体
３と加圧接触して設置される。図８は圧電セラミック２
に形成される駆動電極構造の構造図であり、１／４波長
だけ位置的にずれた２組の駆動電極ＡとＢを形成してい
る。駆動電極ＡとＢはそれぞれ１／２波長相当の長さを
持つ小電極群からなっている。電極ＣとＤはそれぞれ３
／４波長と１／４波長相当の長さを持ち、駆動電極Ａと
Ｂに１／４波長の位置的なずれを作るために形成してい
る。駆動電極ＡとＢに、それぞれ９０度位相の異なる２
つの交流電圧を印加すると、それぞれの交流電圧による
撓み振動の定在波が重畳され、図９に示すような径方向
の変位分布を有する径方向１次、周方向３次以上の撓み
振動の進行波が振動体３に励振される。この進行波の波
頭の横方向成分により、移動体６は摩擦駆動され回転運
動をする。そして、駆動電極ＡとＢに印加する２つの交
流電圧の位相差９０度の符号を逆にすると、振動体３に
励振される撓み振動の進行波の進行方向を変えることが
でき、その結果移動体６の回転方向を変えることができ
る。2. Description of the Related Art A conventional ultrasonic motor and its driving method will be described below with reference to the drawings. FIG.
Is a partially cutaway perspective view of an annular ultrasonic motor,
A vibrating body 3 is formed by bonding an annular piezoelectric ceramic 2 as a piezoelectric body to one of the annular surfaces of an annular elastic substrate 1. Reference numeral 4 denotes a friction material made of an abrasion-resistant material, and reference numeral 5 denotes an elastic body. The moving body 6 is placed in pressure contact with the vibrating body 3 by a pressing means (not shown) via the friction material 4. FIG. 8 shows the piezoelectric ceramic 2
FIG. 3 is a structural diagram of a drive electrode structure formed in FIG. 2, in which two sets of drive electrodes A and B shifted in position by 波長 wavelength are formed. The drive electrodes A and B are each composed of a small electrode group having a length corresponding to a half wavelength. Electrodes C and D are each 3
It has a length equivalent to ４ wavelength and １ ／ wavelength, and is formed in order to create a positional shift of 駆 動 wavelength between the drive electrodes A and B. The drive electrodes A and B have two phases each having a phase difference of 90 degrees.
When two AC voltages are applied, each AC voltage
The standing wave of the bending vibration is superimposed, and a traveling wave of the bending vibration of the primary in the radial direction and the tertiary in the circumferential direction having the radial displacement distribution as shown in FIG. Due to the transverse component of the wave front of the traveling wave, the moving body 6 is driven by friction and rotates. When the sign of the phase difference of 90 degrees between the two AC voltages applied to the drive electrodes A and B is reversed ,
The traveling direction of the traveling wave of the excited bending vibration can be changed, and as a result, the rotation direction of the moving body 6 can be changed.
【０００３】[0003]
【発明が解決しようとする課題】以上説明したように、
従来の超音波モータの駆動方法では、振動体を構成する
圧電セラミックに形成された２つの駆動電極に印加する
２つの交流電圧の位相差９０度の符号を反転して、振動
体に励振される撓み振動の進行波の進行方向を変えて移
動体の回転方向を反転していた。As described above,
In the conventional ultrasonic motor driving method, by reversing the sign of the phase difference 90 ° between two of the AC voltage applied to the two driving electrodes formed in the piezoelectric ceramic constituting the vibrator, the vibration
The traveling direction of the traveling wave of the bending vibration excited by the body is changed to reverse the rotation direction of the moving body.
【０００４】しかし、従来の超音波モータの駆動方法で
は、移動体の反転動作のために２つ の交流電圧の位相差
９０度の符号を反転させた後も、振動体中の撓み振動の
振幅値は急激には変化しないので進行波の方向は急激に
は変わらない。つまり、２つの駆動電極に印加する２つ
の交流電圧のうち１つの交流電圧の位相を反転させ、も
う１つの交流電圧はそのままであるので、反転させない
交流電圧による撓み振動の振幅値の大きさはそのまま
で、反転させた交流電圧による撓み振動の振幅値の大き
さは、反転させる前の撓み振動と反転させた後の撓み振
動とが逆位相であるため一時的に０になり、その後に位
相を反転させた撓み振動になる。その結果、反転動作の
ため２つの交流電圧の位相差９０度の符号を反転させた
後には撓み振動の進行波は減衰していき定在波が励振さ
れて、やがて進行方向が反転した進行波が励振される。
振動体中に進行波が励振されているときには、進行波の
振幅は一定であるので進行波の波頭で振動体と移動体が
常に接触しているが、振動体中に定在波が励振されてい
るときには、定在波の振幅は周波数の２倍の周期で変化
しているので、その振幅が大きくなった時には振動体と
移動体は接触し、移動体の慣性により移動体はその位置
をほぼ維持するので、定在波の振幅が小さくなった時に
は振動体と移動体の接触はなくなる。つまり、振動体と
移動体の接触は定在波の振幅が大きくなる瞬間だけであ
り、見かけ上、振動体と移動体の摩擦はきわめて小さく
なる。 However, in the conventional method of driving an ultrasonic motor, the phase difference between two AC voltages due to the reversal operation of the moving body is determined.
Even after reversing the sign of 90 degrees, the amplitude of the bending vibration in the vibrating body does not change suddenly, so the direction of the traveling wave suddenly changes.
Does not change. That is, the two applied to the two drive electrodes
Inverts the phase of one of the AC voltages
Since the other AC voltage is the same, it is not inverted
The magnitude of the amplitude of the bending vibration due to the AC voltage remains unchanged
The magnitude of the amplitude value of the bending vibration due to the inverted AC voltage
The deflection vibration before inversion and the deflection vibration after inversion
Because the phase is opposite to that of the
It becomes a bending vibration in which the phases are reversed. As a result, the inversion operation
Therefore, the sign of the phase difference of 90 degrees between the two AC voltages was inverted.
Later, the traveling wave of the bending vibration is attenuated and the standing wave is excited.
Then, the traveling wave whose traveling direction is reversed is excited.
When a traveling wave is excited in the vibrating body, the traveling wave
Since the amplitude is constant, the vibrating body and the moving body
Always in contact, but a standing wave is excited in the vibrating body.
The amplitude of the standing wave changes at twice the frequency
When the amplitude increases, the vibration
The moving object touches, and the moving object moves to its position due to the inertia of the moving object.
So that when the amplitude of the standing wave decreases,
In this case, there is no contact between the vibrating body and the moving body. In other words, the vibrator and
Contact of the moving object only occurs at the moment when the amplitude of the standing wave increases.
The apparent friction between the vibrating body and the moving body is extremely small
Become.
【０００５】このように超音波モータの反転動作時には
速度変化時と異なり、反転させない交流電圧による撓み
振動の定在波のみが存在するという反転時独特の動作状
況を示す。そのため、同回転方向で移動体の速度を変え
る時などに比べて特に移動体と振動体との摩擦力が小さ
く、回転停止に対する制動力が小さい。つまり、従来の
超音波モータの駆動方法では、回転速度の変化時には定
在波が励振されないので、比較的高速に回転速度を変化
させることができるが、反転時には一時的に定在波が励
振されるので高速に反転動作させることは困難である。 As described above, during the reversing operation of the ultrasonic motor,
Deflection due to AC voltage that does not reverse unlike when changing speed
Unique behavior during inversion where only standing waves of vibration are present
Show the situation. Therefore, change the speed of the moving body in the same rotation direction
Especially when the moving body and the vibrating body
And the braking force against rotation stop is small. In other words, conventional
The driving method of the ultrasonic motor
Rotational speed changes relatively fast because standing waves are not excited
However, standing waves are temporarily excited during inversion.
Therefore, it is difficult to perform the reversing operation at high speed.
【０００６】したがって図１０に示すように、超音波モ
ータの反転信号ＳＲにより２つの駆動電極に印加する２
つの交流電圧の位相差の符号を反転しても、移動体は慣
性によりしばらくの間は反転せずにそのままの方向に回
転し、遅延時間ｔｄの後初めて反転を行なうことにな
る。したがって、反転周期を高くして行くと移動体が追
随できなくなるという問題があった。Therefore, as shown in FIG. 10, the two signals applied to the two drive electrodes by the inversion signal SR of the ultrasonic motor are
Even if the sign of the phase difference between the two AC voltages is inverted, the moving body rotates in the same direction without being inverted for a while due to inertia, and performs the inversion only after the delay time td. Therefore, there is a problem that the moving body cannot follow the inversion cycle if the reversal cycle is increased.
【０００７】本発明は上記従来の問題点を解決するもの
で、移動体の高速反転が可能な超音波モータの駆動方法
を提供することを目的とする。An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a method of driving an ultrasonic motor capable of reversing a moving body at high speed.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に本発明の超音波モータの駆動方法は、移動体の回転方
向を反転する直前に、駆動電圧を所定の時間だけ０にし
て、その後２つの駆動電圧の位相差値の符号を逆にし
て、上記移動体の回転方向を反転させるか、または移動
体の回転方向を反転する直前の所定の時間だけ駆動電圧
の振幅を低下させて、その後駆動電圧の位相差値の符号
を逆にして移動体を反転させるか、もしくは移動体の回
転方向を反転する直前の所定の時間だけ駆動電圧の振幅
を低下させて、その後駆動電圧を所定の時間だけ０にし
て、さらにその後２つの駆動電圧の位相差値の符号を逆
にして移動体を反転させるようにしている。In order to achieve the above object, a driving method of an ultrasonic motor according to the present invention is to reduce a driving voltage to 0 for a predetermined time immediately before reversing the rotating direction of a moving body. By inverting the sign of the phase difference value between the two drive voltages, the rotational direction of the moving body is reversed, or the drive voltage is reversed for a predetermined time immediately before the rotational direction of the movable body is reversed.
To reduce the amplitude of the driving voltage, and then invert the moving body by reversing the sign of the phase difference value of the driving voltage, or reduce the amplitude of the driving voltage for a predetermined time immediately before reversing the rotating direction of the moving body. After that, the driving voltage is set to 0 for a predetermined time, and thereafter, the sign of the phase difference value between the two driving voltages is reversed to reverse the moving body.
【０００９】[0009]
【作用】上記の方法により、移動体の回転方向を反転す
る直前に、２つの駆動電圧を所定の時間だけ０にして、
振動体に励振された進行波が減衰した後、２つの駆動電
圧の位相差値の符号を逆にして、移動体の回転方向を反
転させるか、または、移動体の回転方向を反転する直前
の所定の時間だけ２つの駆動電圧の振幅を低下させて、
振動体に励振された進行波の振幅を小さくし、その後２
つの駆動電圧の位相差値の符号を逆にして移動体を反転
させるか、もしくは移動体の回転方向を反転する直前の
所定の時間だけ２つの駆動電圧の振幅を低下させて、振
動体に励振された進行波の振幅を小さくし、その後２つ
の駆動電圧を所定の時間だけ０にして、振動体に励振さ
れた進行波が減衰した後、２つの駆動電圧の位相差値の
符号を逆にして、移動体を反転させることにより、移動
体の反転時に振動体に励振される定在波の振幅を０にす
るか、励振しても移動体の反転動作に影響しないように
小さくすることにより、移動体の反転速度を上げるもの
である。 According to the above method, the rotating direction of the moving body is reversed.
Immediately before the two drive voltages are set to 0 for a predetermined time,
After the traveling wave excited by the vibrating body attenuates, two drive
The sign of the pressure phase difference value is reversed,
Or just before reversing the direction of rotation of the moving object
The amplitudes of the two drive voltages are reduced for a predetermined time,
Reduce the amplitude of the traveling wave excited by the vibrating body, and then
Invert the moving object by reversing the sign of the phase difference value of the two drive voltages
Or just before reversing the direction of rotation of the moving object.
The amplitude of the two drive voltages is reduced for a predetermined time,
Reduce the amplitude of the traveling wave excited by the moving body, and then
The drive voltage of is set to 0 for a predetermined time, and
Of the phase difference between the two drive voltages
By moving the sign by reversing the sign,
Set the amplitude of the standing wave excited by the vibrating body to 0 when the body is inverted.
Or the excitation does not affect the flipping motion of the moving object.
By increasing the reversal speed of a moving object by making it smaller
It is.
【００１０】[0010]
【実施例】以下、図面に従って本発明の実施例を説明す
る。Embodiments of the present invention will be described below with reference to the drawings.
【００１１】（実施例１） 図１は本発明の超音波モータの駆動方法の第１の実施例
のブロック図であり、同図において、７は発振回路であ
り、超音波モータの駆動信号を出力する。８は発振回路
７の出力交流信号を所定の位相差（９０度）を有する２
つの駆動信号に分割する分割回路である。分割回路８の
２出力のうち１出力は電力増幅器１１に入力され、もう
１出力は排他的論理和回路でできた反転回路９に入力さ
れた後、電力増幅器１２に入力される。ここで反転回路
９は反転信号ＳＲによって駆動信号を反転させて、超音
波モータ駆動の２つの駆動信号の位相差を９０度遅らせ
たり進めたりする役目を果たす。そして、それぞれの駆
動信号は電力増幅器１１、１２によって超音波モータ１
３を駆動するに充分なレベルにまで増幅され、超音波モ
ータ１３の圧電体に形成された２つの駆動電極から取り
出された２つの駆動端子にそれぞれ印加される。一方、
１０ａ、ｂは論理積回路でできた駆動停止回路で駆動停
止信号ｓｓによって、駆動信号の振幅を０にすることが
できる。(Embodiment 1) FIG. 1 is a block diagram of a first embodiment of a method of driving an ultrasonic motor according to the present invention. In FIG. 1, reference numeral 7 denotes an oscillation circuit which generates a driving signal of the ultrasonic motor. Output. Reference numeral 8 designates an output AC signal of the oscillation circuit 7 having a predetermined phase difference (90 degrees).
This is a dividing circuit for dividing the driving signal into two driving signals. One of the two outputs of the dividing circuit 8 is input to the power amplifier 11, and the other output is input to the inverting circuit 9 made of an exclusive OR circuit, and then to the power amplifier 12. Here, the inversion circuit 9 inverts the drive signal by the inversion signal SR, and plays a role of delaying or advancing the phase difference between the two drive signals of the ultrasonic motor drive by 90 degrees. Each drive signal is transmitted to the ultrasonic motor 1 by power amplifiers 11 and 12.
3 is amplified to a level sufficient to drive, taken from two driving electrodes formed in the piezoelectric body of the ultrasonic motor 13
They are respectively applied to the issued two drive terminals. on the other hand,
Numerals 10a and 10b denote a drive stop circuit made up of a logical product circuit, which can set the amplitude of the drive signal to 0 by a drive stop signal ss.
【００１２】図２は、図１に示した駆動回路の動作のタ
イミングチャートである。反転信号ＳＲは反転回路９に
入力され、論理的１の時は一方の駆動信号を反転させ、
論理的０の時は駆動信号ＳＤをそのまま通過させる。す
なわち、論理的１の時がｃｗ方向の回転なら、論理的０
の時はｃｃｗ方向の回転をさせる。振動体に弾性波を励
振していない時よりも励振している時の方が、移動体と
振動体との間の摩擦力は小さく、移動体に対する制動力
が小さくなる。従来の駆動法では反転信号ＳＲにより反
転指示を出しても、振動体には常に弾性波が励振されて
いるので、制動力が十分に効かず、移動体は慣性により
しばらくの間は反転せずにそのままの方向に回転し、遅
延時間ｔｄの後初めて反転を行う。つまり、従来の超音
波モータの駆動方法では、移動体の反転動作のために２
つの交流電圧の位相差９０度の符号を反転させた後も、
振動体中の進行波の振幅はすぐには０にならず、しかも
２ つの駆動電極に印加する２つの交流電圧のうち１つの
交流電圧の位相を反転させることにより、反転させない
交流電圧による撓み振動の振幅値の大きさはそのまま
で、反転させる交流電圧による撓み振動の振幅値の大き
さは、反転させる前の撓み振動と反転させた後の撓み振
動とが逆位相であるため一時的に０になり、その時には
反転させない交流電圧による撓み振動の定在波のみが存
在することになるので、特に移動体と振動体との摩擦力
が小さく、また回転停止に対する制動力が小さかった。
ここで、本実施例では、移動体の回転方向を反転する直
前に、駆動停止回路１０ａ、１０ｂに入力される駆動停
止信号ＳＳにより上記２つの駆動電圧を両方とも所定の
駆動停止時間ｔＳだけ０にして、進行波を構成する２つ
の定在波をともに減衰させ、定在波を励振することがな
いので反転時にも制動力を上げることができる。そし
て、移動体の回転をほぼ止めた後、反転回路９に入力さ
れる反転信号ＳＲにより上記２つの駆動電圧の所定の位
相差値の符号を逆にした駆動信号を電力増幅器１１、１
２に入力して増幅した後、超音波モータ１３を駆動して
いるので、移動体の回転方向を高速に反転させることが
できる。 FIG. 2 is a timing chart of the operation of the drive circuit shown in FIG. The inversion signal SR is input to the inversion circuit 9, and when it is logical 1, one of the drive signals is inverted.
When it is logical 0, the drive signal SD is passed as it is. That is, if the logical 1 is a rotation in the cw direction, a logical 0
In the case of, rotation in the ccw direction is performed. The frictional force between the moving body and the vibrating body is smaller when the elastic body is excited than when the elastic wave is not excited, and the braking force on the moving body is smaller. In the conventional driving method, even if an inversion instruction is issued by the inversion signal SR, since the elastic body is always excited by the vibrating body, the braking force is not sufficiently effective, and the moving body does not invert for a while due to inertia. rotate to the exact direction in the slow
The reversal is performed only after the delay time td . In other words, conventional supersonic
In the driving method of the wave motor, two
After inverting the sign of the phase difference of 90 degrees between the two AC voltages,
The amplitude of the traveling wave in the vibrator does not immediately become zero, and
One of the two AC voltages applied to the two drive electrodes
Does not invert by inverting the phase of AC voltage
The magnitude of the amplitude of the bending vibration due to the AC voltage remains unchanged
The magnitude of the amplitude value of the bending vibration due to the AC voltage to be reversed
The deflection vibration before inversion and the deflection vibration after inversion
It is temporarily 0 because the phase is opposite to the motion.
Only standing wave of bending vibration due to AC voltage that does not reverse exists
In particular, the frictional force between the moving body and the vibrating body
And the braking force against rotation stop was small.
Here, in the present embodiment, immediately before reversing the rotation direction of the moving body, the drive stop input to the drive stop circuits 10a and 10b is stopped.
With the stop signal SS, the two drive voltages are both set to 0 for a predetermined drive stop time tS, and the two
Attenuate both standing waves and excite the standing waves.
Therefore, the braking force can be increased even at the time of reversal. Soshi
Te, after nearly stopping the rotation of the moving body, is input to the inverting circuit 9
The predetermined positions of the two drive voltages are determined by the inverted signal SR.
The drive signal having the opposite sign of the phase difference value is transmitted to the power amplifiers 11 and 1.
2 and amplified, then drive the ultrasonic motor 13
So that the direction of rotation of the moving object can be reversed at high speed.
it can.
【００１３】（実施例２） 図３は本発明の第２の実施例を示す。第１の実施例と共
通する部材および信号は同番号、同記号を付して説明は
省略する。第１の実施例と異なるのは駆動停止回路１０
ａ、１０ｂをなくし、かわりに電力増幅器１１、１２に
振幅低下信号ＳＡを入力している。この信号は入力され
る駆動信号の振幅を低下させ、ひいては電力増幅器１
１，１２の出力を低下させる機能を持っている。Embodiment 2 FIG. 3 shows a second embodiment of the present invention. Members and signals common to those of the first embodiment are denoted by the same reference numerals and symbols, and description thereof is omitted. The first embodiment and different to the drive stop circuit 10
a, eliminate 10b, have entered the amplitude reduction signal SA to the power amplification device 11, 12 in place. This signal reduces the amplitude of the input drive signal, and consequently the power amplifier 1.
It has the function of lowering the output of 1,12.
【００１４】図４は、図３に示した駆動回路の動作のタ
イミングチャートである。反転信号ＳＲにより移動体に
ｃｗ方向、またはｃｃｗ方向の回転をさせるのである
が、移動体の回転方向を反転する直前に、上記２つの駆
動電圧を両方とも振幅低下信号ＳＡにより所定の振幅低
下時間ｔＡだけ進行波の振幅を小さくすることにより制
動力を上げて、移動体の回転を十分に小さくした後、上
記２つの駆動電圧の所定の位相差値の符号を逆にして、
移動体の回転方向を高速に反転させる。FIG. 4 is a timing chart of the operation of the drive circuit shown in FIG. The mobile unit is caused to rotate in the cw direction or the ccw direction by the inversion signal SR. Immediately before the rotation direction of the mobile unit is inverted, both of the two drive voltages are changed by the amplitude reduction signal SA for a predetermined amplitude reduction time. After increasing the braking force by reducing the amplitude of the traveling wave by tA and sufficiently reducing the rotation of the moving body, the signs of the predetermined phase difference values of the two drive voltages are reversed,
The direction of rotation of the moving body is reversed at high speed.
【００１５】本実施例では、移動体の反転動作に先だっ
て２つの駆動信号の振幅を小さくして、振動体中の進行
波の振幅を小さくした後、２つの駆動電極に印加する２
つの交流電圧のうち１つの交流電圧の位相を反転させる
ことにより、振動体中の進行波と撓み振動の定在波が存
在しても、その振幅値を共に小さくすることができるの
で、反転動作時にも移動体と振動体との摩擦力を大きく
でき、また回転停止に対する制動力も大きくできるの
で、高速の反転動作を行うことができる。 In this embodiment, prior to the reversing operation of the moving body,
To reduce the amplitude of the two drive signals
After reducing the amplitude of the wave, apply 2 to the two drive electrodes.
Inverts the phase of one of the AC voltages
As a result, traveling waves in the vibrating body and standing waves of
Even if it exists, the amplitude value can be reduced together
Increases the frictional force between the moving body and the vibrating body even during reverse operation.
Can also increase the braking force against rotation stop
Thus, a high-speed inversion operation can be performed.
【００１６】（実施例３） 図５は本発明の第３の実施例を示す。この実施例は前記
第１の実施例と第２の実施例を複合したものである。(Embodiment 3) FIG. 5 shows a third embodiment of the present invention. This embodiment is a combination of the first embodiment and the second embodiment.
【００１７】図６は、図５に示した駆動回路の動作のタ
イミングチャートである。反転信号ＳＲにより、上記の
実施例と同様に、たとえば論理的１の時がｃｗ方向の回
転なら、論理的０の時はｃｃｗ方向の回転をさせること
ができる。移動体の回転方向を反転する直前に、まず２
つの駆動電圧を両方とも振幅低下信号ＳＡにより所定の
振幅低下時間ｔＡだけ、進行波の振幅を小さくし制動力
を上げて、その後に２つの駆動電圧を両方とも駆動停止
信号ＳＳにより、所定の駆動停止時間ｔＳだけ０にし
て、進行波を速やかに減衰させることにより制動力をさ
らに上げて、移動体の回転をほぼ止めた後、２つの駆動
電圧の所定の位相差値の符号を逆にして、移動体の回転
方向を高速に反転させる。FIG. 6 is a timing chart of the operation of the drive circuit shown in FIG. By the inversion signal SR, for example, when the logical value is 1 the rotation is in the cw direction, and when the logical value is 0, the rotation is in the ccw direction, as in the above embodiment. Immediately before reversing the rotation direction of the moving object,
The two drive voltages are both reduced by the amplitude reduction signal SA for a predetermined amplitude reduction time tA to reduce the amplitude of the traveling wave to increase the braking force, and then the two drive voltages are both reduced to the predetermined drive by the drive stop signal SS. and 0 only downtime tS, further increasing the braking force by attenuating the speed Ya or traveling waves, after nearly stopping the rotation of the moving body, opposite the sign of the predetermined phase difference value of the two driving voltages Then, the rotating direction of the moving body is reversed at high speed.
【００１８】つまり、本実施例の超音波モータの駆動方
法では、移動体の反転動作に先だって２つの駆動信号の
振幅を小さくして、振動体中の進行波の振幅を小さくし
て、その後、２つの駆動信号の振幅を０にして、振動体
中の進行波を確実に減衰させてから、２つの駆動電極に
印加する２つの交流電圧のうち１つの交流電圧の位相を
反転させることにより、振動体中の進行波を減衰させ、
定在波の振幅値を確実に小さくすることができるので、
反転動作時にも移動体と振動体との摩擦力を大きくで
き、また回転停止に対する制動力も大きくできる。 That is, the driving method of the ultrasonic motor of this embodiment
In the method, two driving signals are
Reduce the amplitude to reduce the amplitude of the traveling wave in the vibrating body.
Then, the amplitude of the two drive signals is set to 0,
After attenuating the traveling wave, the two drive electrodes
The phase of one of the two applied AC voltages is
By inverting, the traveling wave in the vibrating body is attenuated,
Since the amplitude of the standing wave can be reliably reduced,
Even during reversing operation, the frictional force between the moving
And the braking force against rotation stop can be increased.
【００１９】[0019]
【発明の効果】以上の説明で明らかなように本発明の駆
動方法によれば、反転動作に先立って２つの駆動電圧を
所定の時間だけ０にして、振動体に励振された進行波が
減衰した後、２つの交流駆動電圧の位相差９０度の符号
を反転させて、移動体の回転方向を反転させるか、また
は、移動体の回転方向を反転する直前の所定の時間だけ
駆動電圧を低下させて、振動体に励振された進行波の振
幅を小さくし、その後２つの交流駆動電圧の位相差９０
度の符号を反転させて、移動体を反転させるか、もしく
は移動体の回転方向を反転する直前の所定の時間だけ駆
動電圧を低下させて、振動体に励振された進行波の振幅
を小さくし、その後２つの駆動電圧を両方とも所定の時
間だけ０にして、振動体に励振された進行波が減衰した
後、２つの交流駆動電圧の位相差９０度の符号を反転さ
せて、移動体を反転させることにより高速反転動作がで
きる超音波モータの駆動方法を提供できる。As is apparent from the above description, according to the driving method of the present invention , prior to the inversion operation, the two driving voltages are set to 0 for a predetermined time to attenuate the traveling wave excited by the vibrating body. After that, the sign of the phase difference 90 degrees between the two AC drive voltages
To reduce the amplitude of the traveling wave excited by the vibrating body by inverting the rotating direction of the moving body, or reducing the driving voltage for a predetermined time immediately before reversing the rotating direction of the moving body. And then the phase difference 90 between the two AC drive voltages
By inverting the sign of the degree and inverting the moving body , or by lowering the drive voltage for a predetermined time immediately before reversing the rotating direction of the moving body, the amplitude of the traveling wave excited by the vibrating body is reduced. After that, the two driving voltages are both set to 0 for a predetermined time, and after the traveling wave excited by the vibrating body is attenuated , the sign of the phase difference of 90 degrees between the two AC driving voltages is inverted.
In addition, it is possible to provide an ultrasonic motor driving method capable of performing a high-speed reversal operation by reversing the moving body.
【図１】本発明の駆動方法の１実施例の駆動回路のブロ
ック図FIG. 1 is a block diagram of a driving circuit according to an embodiment of a driving method of the present invention.
【図２】同駆動回路のタイミングチャートFIG. 2 is a timing chart of the driving circuit.
【図３】本発明の第２の実施例の駆動回路のブロック図FIG. 3 is a block diagram of a driving circuit according to a second embodiment of the present invention.
【図４】同駆動回路のタイミングチャートFIG. 4 is a timing chart of the driving circuit.
【図５】本発明の第３の実施例の駆動回路のブロック図FIG. 5 is a block diagram of a drive circuit according to a third embodiment of the present invention.
【図６】同駆動回路のタイミングチャートFIG. 6 is a timing chart of the drive circuit.
【図７】円環形超音波モータの一部切り欠き斜視図FIG. 7 is a partially cutaway perspective view of an annular ultrasonic motor.
【図８】円環形圧電体の電極構造図FIG. 8 is a diagram showing an electrode structure of an annular piezoelectric body.
【図９】円環形超音波モータの振動体の径方向の振動変
位図FIG. 9 is a diagram illustrating a vibration displacement diagram in a radial direction of a vibrating body of an annular ultrasonic motor.
【図１０】従来の超音波モータ駆動方法の動作のタイミ
ングチャートFIG. 10 is a timing chart of the operation of the conventional ultrasonic motor driving method.
１ 弾性基板 ２ 圧電体 ３ 振動体 ６ 移動体７ 発振回路 ８ 分割回路 ９ 反転回路（位相差値の符号を逆にする回路）１０ａ １０ｂ 駆動停止回路 １１ １２ 電力増幅器 １３ 超音波モータ ＳＲ 反転信号（回転方向を反転する信号） ＳＳ 駆動停止信号（駆動電圧を０にする信号） ＳＡ 振幅低下信号（駆動電圧を低下させる信号）DESCRIPTION OF SYMBOLS 1 Elastic substrate 2 Piezoelectric body 3 Vibrating body 6 Moving body 7 Oscillation circuit 8 Dividing circuit 9 Inverting circuit ( circuit for reversing the sign of the phase difference value) 10a 10b Driving stop circuit 11 12 Power amplifier 13 Ultrasonic motor SR Inverted signal ( A signal for inverting the rotation direction) SS Driving stop signal (signal for setting the driving voltage to 0) SA Amplitude reduction signal (signal for lowering the driving voltage)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 武田 克 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 平３−11984（ＪＰ，Ａ) 特開 平３−270678（ＪＰ，Ａ) 特開 平２−214482（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) H02N 2/00 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsushi Takeda 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-11984 (JP, A) JP-A-3-3- 270678 (JP, A) JP-A-2-214482 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) H02N 2/00
Claims (3)
成し、上記振動体に加圧接触して移動体を設置し、上記
圧電体に１／４波長だけ位置をずらせて形成された２組
の駆動電極に、それぞれ９０度の位相差を持った駆動交
流電圧を印加して上記振動体に進行波を励振し、上記移
動体を移動させる超音波モータの駆動方法において、 上記移動体の回転方向を反転する直前に、上記２つの駆
動交流電圧の振幅値を所定の時間だけ０にして、その後
上記２つの駆動交流電圧の上記９０度の位相差の符号を
逆にして再び２組の駆動電極にそれぞれ上記２つの駆動
交流電圧を印加して、上記移動体の回転方向を反転する
ことを特徴とする超音波モータの駆動方法。1. A bonded piezoelectric elastic board constitute a vibration member, established the moving body in pressure contact with the vibration member, formed by shifting a 1/4 wavelength position on the piezoelectric the two sets of drive electrodes, the drive exchange having a phase difference of 90 degrees
In a driving method of an ultrasonic motor for moving a moving body by exciting a traveling wave to the vibrating body by applying a flowing voltage, the amplitudes of the two driving AC voltages just before reversing a rotation direction of the moving body. The value is set to 0 for a predetermined time, then the sign of the 90-degree phase difference between the two drive AC voltages is reversed, and the two drive electrodes are again applied to two sets of drive electrodes, respectively.
A method for driving an ultrasonic motor, comprising: applying an AC voltage to invert the rotation direction of the moving body.
の時間だけ２つの駆動交流電圧の振幅値を低下させて、
その後上記２つの駆動交流電圧の９０度の位相差の符号
を逆にして再び２組の駆動電極にそれぞれ上記２つの駆
動交流電圧を印加して、上記移動体の回転方向を反転す
ることを特徴とする請求項１記載の超音波モータの駆動
方法。2. The method according to claim 1, wherein the amplitudes of the two drive AC voltages are reduced for a predetermined time immediately before reversing the rotation direction of the moving body.
Thereafter, the signs of the 90-degree phase difference between the two drive AC voltages are reversed, and the two drive electrodes are again applied to the two drive electrodes, respectively.
2. The method of driving an ultrasonic motor according to claim 1, wherein the rotating direction of the moving body is reversed by applying a dynamic AC voltage .
の時間だけ２つの駆動交流電圧の振幅値を低下させて、
その後上記２つの駆動交流電圧の振幅値を所定の時間だ
け０にして、さらにその後上記２つの駆動交流電圧の９
０度の位相差の符号を逆にして再び２組の駆動電極にそ
れぞれ上記２つの駆動交流電圧を印加して、上記移動体
の回転方向を反転することを特徴とする請求項１記載の
超音波モータの駆動方法。3. The method according to claim 1, wherein the amplitudes of the two drive AC voltages are reduced for a predetermined time immediately before reversing the rotation direction of the moving body.
Thereafter, the amplitude values of the two driving AC voltages are set to 0 for a predetermined time, and then the amplitude values of the two driving AC voltages are set to 9
The sign of the phase difference of 0 degrees is reversed, and the two drive electrodes are again
2. The ultrasonic motor driving method according to claim 1, wherein the two driving AC voltages are respectively applied to reverse the rotation direction of the moving body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3090378A JP2990836B2 (en) | 1991-04-22 | 1991-04-22 | Driving method of ultrasonic motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3090378A JP2990836B2 (en) | 1991-04-22 | 1991-04-22 | Driving method of ultrasonic motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04322180A JPH04322180A (en) | 1992-11-12 |
| JP2990836B2 true JP2990836B2 (en) | 1999-12-13 |
Family
ID=13996909
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3090378A Expired - Fee Related JP2990836B2 (en) | 1991-04-22 | 1991-04-22 | Driving method of ultrasonic motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2990836B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1118461A (en) * | 1997-06-26 | 1999-01-22 | Canon Inc | Vibrating-type drive device controller and device therewith |
| JP4442965B2 (en) | 1999-11-01 | 2010-03-31 | セイコーインスツル株式会社 | Ultrasonic motor and electronic device with ultrasonic motor |
-
1991
- 1991-04-22 JP JP3090378A patent/JP2990836B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04322180A (en) | 1992-11-12 |
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