JP2000190093A - Control method for positioning device and actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for positioning a work at a given position accurately. SOLUTION: This device comprises an action part 40, a transmission axis 18 for transmitting the movement to the action part 40, an actuator 10 for driving the transmission axis 18, a control device 50 for controlling the actuator 10, and a control means 19 for controlling the movement of the action part 40 or a position detecting means for detecting the position of the action part 40 to the transmission axis 18 and/or the action part 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device (robot or NC device) for positioning a work at a predetermined position, such as a positioning device (robot or NC device) for positioning a work at a predetermined position. It relates to the technique of positioning well.

[0002]

2. Description of the Related Art In a robot or an NC apparatus, it is required to accurately position an operation section such as a robot arm at a predetermined position. In particular, in a positioning device that holds a work at a predetermined position in an automobile assembling process, there is a strong demand for the positioning accuracy because the positioning accuracy is the product accuracy. As such an apparatus, an apparatus described in Japanese Patent Application Laid-Open No. 4-224095 is known. In this positioning device, a mechanism is disclosed in which a ball screw is driven by a servomotor and a work positioning member (operating portion) that engages with the ball screw is positioned at a predetermined position.
A servo motor incorporating a braking device is used as such a servo motor, and a work positioning member is held at a positioning position.

[0003]

However, in the conventional positioning device, the positioning member (operating portion) for holding the work is moved from the positioning position due to disturbance by a working robot such as a welding robot or an error existing in the device itself. There was a problem of slippage. If the positioning member is displaced, the position of the work is also displaced, resulting in a decrease in work accuracy.

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a technique capable of accurately positioning a work at a predetermined position. .

[0005]

According to one aspect of the present invention, there is provided a positioning device according to the present invention. According to the positioning device of claim 1, the power of the actuator is transmitted to the operation unit via the transmission shaft,
The operating part is positioned. At this time, since the transmission shaft and / or the operating unit is provided with the braking means, the operating unit is hardly displaced even when an external force acts on the operating unit, and the operating unit is held at a predetermined position. Therefore, positioning can be performed accurately even when an external force acts on the operation section. In the past, the holding force was increased by providing a braking device on the actuator, but when the working accuracy became higher, a displacement occurred at the connection between the transmission shaft and the actuator even when the actuator was braked, resulting in a higher position accuracy. Cannot be maintained high. However, claim 1
According to the described positioning device, such a problem can be solved by directly braking the transmission shaft and / or the operating part.

For example, in a positioning device that transmits the power of an actuator to a transmission shaft via a speed reducer, the movement of the actuator may not be directly transmitted to the transmission shaft due to lost motion or the like by the speed reducer. In such a case, the positioning device described in claim 2 is particularly effective. In the device according to claim 2, a detecting means for detecting a physical quantity related to the angle of the transmission shaft or a detecting means for detecting a physical quantity related to the position of the operating unit is provided.
The actuator is driven based on the value detected by the detecting means. Therefore, since the actuator is directly driven based on the value detected by the transmission shaft or the operation unit, the actuator is driven without being affected by error factors such as a speed reducer interposed between the actuator and the transmission shaft. Therefore, the operation unit can be accurately positioned at a predetermined position. Here, the physical quantity related to the angle of the transmission shaft is
It refers to values such as the angle, angular velocity, and angular acceleration of the transmission shaft (rotary shaft), and refers to all physical quantities for which the position of the operating unit can be determined from the detected values. Further, the physical quantity related to the position of the operating unit refers to values of the position, speed, acceleration, etc. of the operating unit,
It refers to all physical quantities for which the position of the operating unit can be obtained from the detected value.

Further, when a detecting means for detecting a physical quantity relating to the angle of the transmission shaft is provided on the transmission shaft as in the positioning device according to the second aspect, the control method of the actuator according to the third aspect is effective. is there. According to the above control method,
Determine the difference between the position of the moving part estimated based on the command value to the actuator or the value detected by the actuator and the actual position of the moving part detected by the transmission shaft or moving part, and correct the command value to the actuator. I do. Therefore, it is possible to easily correct the command value to the actuator.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a first aspect of the present invention, the transmission shaft to which the power of the actuator is transmitted and / or the operating section is provided with a braking means for braking the movement of the operating section. 2. Description of the Related Art Conventionally, as an example of a commercially available servo motor (actuator), there is one provided with a braking means (brake) for braking the rotation of a rotary shaft of the servo motor. Such a brake is made according to the outer size of the motor. Therefore, when such a servomotor is used, the holding force at the time of positioning is proportional to the motor size. Here, since the positioning device disposed in a work station such as a factory is disposed in a limited space, it is desired that the positioning device be compact. On the other hand, it is desired that the positioning accuracy (positioning holding force) be high so that the position does not change even when a disturbance acts. Therefore, it is required to increase the holding force at the time of positioning without increasing the outer size of the servomotor (without increasing the diameter of the transmission shaft driven by the servomotor). Here, it is possible to specially manufacture servomotors having different brake outer shapes, but if specially manufactured, the cost is increased, which is not preferable. Further, there may be a slight play (lost motion) between the actuator and the transmission shaft, and the method of braking the actuator cannot brake the rotation of the transmission shaft within the range of the lost motion. Was. Therefore, in the first invention of the present invention, a braking means is provided on the transmission shaft and / or the operation unit,
Braking the position of the working part directly. The braking means for achieving this object may be provided at any place as long as it is a transmission shaft or an operating part. However, such braking means
It is preferable to provide the transmission shaft for transmitting the movement of the actuator at an end opposite to the end to which the actuator is mounted. According to this, since the transmission shaft is supported at both ends, it can be easily mounted by attaching the braking means to the bearing portion. Further, it is preferable that such a braking means works only at the time of positioning. In this way, when the operating section moves, the braking means does not become a resistance of the operating section and there is no power loss, so that it is economical. Such a braking unit may be a commercially available general-purpose mechanical brake unit or an electromagnetic brake that electrically applies a brake.

An embodiment of the positioning device according to the first invention will be described below with reference to FIG. FIG. 1 is a drawing showing a schematic configuration of a positioning device. The positioning device includes a control unit 50, a servo motor module 10 controlled by the control unit 50, and a servo motor module 10
A ball screw 18 to which the power is transmitted, and a ball screw 18
And a brake 19 attached to the other end of the ball screw 18.

The control unit 50 is constituted by a general computer, and controls the servo motor module 10 and the brake 19 according to a program stored in a ROM or the like. The control unit 50 is the same as a known control device, and a description of a specific configuration will be omitted.

The servo motor module 10 is a unit in which a servo motor 11, a brake 12, and a position sensor 13 are integrated. As the servo motor 11, A
Various motors such as an electric servomotor such as a C servomotor and a DC servomotor, a hydraulic servomotor, and a pneumatic servomotor can be used. In the present embodiment, an electric servomotor is used to make the positioning device compact by eliminating the need for oil piping and air piping. The brake 12 is a braking means for applying a brake to the output shaft 14 of the servo motor 11. In the present embodiment, a commercially available one in which the servomotor 11 and the brake 12 are integrated is used. However, it is not always necessary to use such a commercially available one, and the brake 12 may be separately attached to the output shaft 14 of the servomotor 11. The position sensor 13 is an output shaft 1 of the servomotor 11.
In the present embodiment, an encoder for detecting an angle change of the output shaft 14 of the servomotor 11 is used as position detection means for detecting an angle change or the like of No. 4. In the present embodiment, an encoder is used as the position sensor 13. However, in addition to the encoder, a sensor for detecting the angle of a potentiometer, a resolver, or the like may be used as the sensor for detecting the angle of the output shaft 14 of the servo motor 11. Any device such as a tachometer that detects the angular velocity of the servomotor may be used. That is, the output shaft 14 of the servomotor 11
Any type can be used as long as a physical quantity related to the angle can be detected. Output shaft 1 of servo motor 11
4 is rotated by the ball screw 18 via the coupling 16.
Is transmitted to The ball screw 18 is engaged with a female screw formed on the operation section 40 and converts the rotation of the ball screw 18 into a linear motion of the operation section 40. That is, in the present embodiment, the ball screw 18 serves as a transmission shaft for transmitting motion to the operation unit 40.

Although not shown, the operating section 40 is provided with a clamp mechanism for holding the work in a predetermined posture. Therefore, the work is also positioned at the predetermined position by positioning the operation section 40 at the predetermined position. Examples of such a clamp mechanism include a pin clamp mechanism that inserts a clamp pin into a hole formed in a workpiece and clamps the workpiece, a gauge plate mechanism that clamps the workpiece with a gauge plate that conforms to the shape of the workpiece, and a mechanical hand that clamps the workpiece. Various clamping mechanisms, such as those, can be used.

The other end of the ball screw 18 is connected to the coupling 1
7 is connected to the brake shaft 15 of the brake 19. The brake 19 may regulate the rotation of the brake shaft 15, that is, the rotation of the ball screw 18 by mechanical force such as friction, or the brake shaft 15 by electric force such as magnetism.
May be used to regulate the rotation of the motor. This brake 1
9, the rotation of the ball screw 18 is restricted, so that even if a force is applied by a work robot or the like to work on the work held by the operation unit 40, the operation unit 40 is held at the target position.

The operation of the positioning device configured as described above will be briefly described. The target position of the operation unit 40 (operation unit 4
When the position of the workpiece held at 0 is given, the servomotor 11 is driven by a predetermined amount and positioned at the target position. At this time, the angle of the output shaft 14 of the servo motor 11 detected by the position sensor 13 is fed back to the control device 50, and the servo motor 11 is controlled so that the position of the operation unit 40 becomes the target position. When the operation unit 40 is positioned, the control device 50 controls the rotation of the ball screw 18 by the brakes 12 and 19. Unlike the conventional device, the holding force is increased by the brake 19 attached to the other end of the ball screw 18, so that the operating unit 40
The operation unit 40 is positioned at a predetermined position even when a force is applied to the operation unit 40.

As described above, in the positioning device described above,
Since the brake 19 is separately provided at the end of the ball screw 18 opposite to the end to which the servo motor module 10 is attached, the holding force at the positioning position of the operation unit 40 is improved, and the operation unit 40 is accurately positioned at a predetermined position. The positioning can be maintained well. Further, since the holding force of the operation unit 40 can be increased by the brake 19, it is not necessary to increase the diameter of the brake 12 of the servo motor module 10. Therefore, a compact servomotor module 10 can be used, and the positioning device itself can be made compact.

Next, another embodiment of the first invention of the present application in which a brake is separately provided in addition to the brake incorporated in the servo motor module 10 will be described with reference to FIG. In the positioning device shown in FIG. 2, the same parts as those in FIG. The positioning device shown in FIG. 2 differs from the positioning device shown in FIG. 1 in that a brake 19 is provided at the other end of the ball screw 18 in the device shown in FIG. 1, whereas the positioning device shown in FIG. This is the point that the servo motor module 20 is provided at the other end. That is, in the device shown in FIG. 2, a servo motor module 20 in which a servo motor 21, a brake 22, and a position sensor 23 are integrated is provided in place of the brake 19 provided. The provision of the servo motor module 20 not only improves the holding force of the operation unit 40 during positioning, but also increases the driving force (drive torque) when the operation unit 40 is moved by the servo motor 21 of the servo motor module 20. There is a point that can be. That is, when the driving force (driving torque) of the operation unit 40 is to be increased by the servo motor module 10 alone, it is necessary to increase the size of the servo motor module 10 itself. This is not preferable because it hinders downsizing of the positioning device. In such a case,
By providing another servo motor module 20 at the other end of the ball screw 18, the servo motor module 10
The driving force can be increased without increasing the size. Since the driving force is increased, the acceleration and rising characteristics of the operation unit 40 are improved, and the positioning time can be reduced.

In the examples shown in FIGS. 1 and 2 described above,
Although the positioning device having the mechanism for linearly moving the operation unit 40 by the ball screw 18 has been described, the first invention of the present application can be applied to other than such a mechanism. Such an example is shown in FIG. 3, the servo motor 11 of the servo motor module 10 is used.
The rotation of the output shaft 14 driven by the
And is transmitted to the transmission shaft 25. An operation unit 40 (robot arm) is attached to the transmission shaft 25, and the transmission shaft 25 and the operation unit 40 rotate integrally. The rotation speed reducer 30 reduces the rotation of the servo motor module 10 and transmits the rotation to the transmission shaft 25. Here, as the rotation speed reducer, any existing types of speed reducers can be used, and for example, a planetary gear speed reduction mechanism using a planetary gear or a harmonic drive speed reduction mechanism can be used. Transmission shaft 2 to which rotation of servo motor module 10 is transmitted
The other end of the bearing 5 is supported by a bearing 31.
A brake 19 is provided at one end. With this brake 19, the holding force at the time of positioning the operating section (robot arm) 40 can be increased. In the embodiment shown in FIG. 3, the brake shoe 27 is attached to the operating section (robot arm) 40 so that the brake shoe 27 and the surface of the surface plate 100 on which the positioning device is installed are brought into contact with a constant surface pressure. ing. Therefore, in the positioning device of the embodiment of FIG. 3, the holding force at the time of positioning the operation unit 40 is further improved by the brake shoe 27 attached to the operation unit 40. As described above, the braking unit for improving the holding force at the time of positioning may be provided in the operation unit 40 other than the transmission shaft. In addition, with this configuration, it is possible to prevent the bending of the operating section (robot arm) 40, which is effective in that respect. However, the brake shoes 27 are always in contact with the surface plate 100 and become a resistance when the operation unit 40 moves, which is not preferable in that the power of the servomotor 11 is lost, and the brake shoes 27 are worn by use. So it is necessary to replace it at regular intervals. Further, in the positioning device shown in FIG.
Since the speed reducer 30 is disposed between the transmission 4 and the transmission shaft 25, there is lost motion due to the speed reducer 30. Therefore, even if the output shaft 14 is braked by the brake 12 of the servo motor module 10, the movement of the operation unit 40 due to the lost motion cannot be braked.
However, in the device shown in FIG. 3, the movement of the operation unit is directly braked by the brake 19 provided on the transmission shaft 25 and the brake shoe 27 provided on the operation unit 40. Can be. In addition,
Naturally, the brake 19 of the positioning device of FIG. 3 may be replaced with a servomotor module 20 as in the positioning device of FIG.

Next, the second invention of the present application will be described.
According to the second aspect of the present invention, the location for detecting the physical quantity for determining the position of the operation unit to be positioned is directly detected not by the output shaft of the actuator but by the transmission shaft or the operation unit that transmits power to the operation unit. Thereby, the positioning accuracy of the operation section 40 is improved. In other words, actuators such as servomotors have recently been used in high-speed type due to the demand for miniaturization. Therefore, when such a motor is used for a positioning device, if the rotation of the motor is transmitted to the transmission shaft as it is, the torque for rotating the operation unit becomes insufficient, and the rotation of the motor is transmitted via the reduction gear. Will be transmitted to the shaft.
When power is transmitted via a speed reducer, a positioning error due to the speed reducer, that is, shaft deflection of the transmission shaft and lost motion occur. For this reason, the motion of the actuator is not transmitted to the transmission shaft, that is, the operation unit, by the amount of the deflection. That is, the relationship shown in FIG. 9 is established between the torque generated on the output shaft of the servomotor and the shaft deflection of the transmission shaft. In FIG. 9, the vertical axis indicates shaft deflection, and the horizontal axis indicates motor torque. Here, the relatively large deflection generated between the torque of 0 and a certain range shown in FIG. 9 is called lost motion. When the transmission shaft is bent by the torque generated in the motor in this manner, the rotation of the actuator cannot be transmitted to the operation unit by the amount of the deflection, resulting in a positioning error of the operation unit. Even when the rotation of the actuator is transmitted to the transmission shaft without the intervention of the speed reducer, the output shaft of the motor and the transmission shaft are connected by some type of connection member (gear or the like). Therefore, in general, the movement of the operation unit estimated from a value detected by an actuator such as a servomotor may be different from the actual movement of the operation unit. Therefore, in the second invention of the present invention, the motion (trajectory) of the operation unit, which is conventionally determined by the motion of the actuator
, By directly detecting the movement of the transmission shaft or the operating unit, the operating unit is accurately positioned. Here, the position of the operating unit can be accurately determined by detecting the movement of the transmission shaft because the movement of the transmission shaft is directly transmitted to the operating unit and there is no play (lost motion) between them. This is because the movement of the part can be accurately detected. According to the second aspect of the present invention, when the power of the actuator is transmitted to the transmission shaft via the speed reducer, the operation unit can be positioned without being affected by the speed reducer. In addition, it is preferable that the position at which the position detecting means is provided is provided at the end of the transmission shaft from the viewpoint of easy attachment of the position detecting means. In addition, since the position of the operation unit can be accurately determined by directly detecting the position of the transmission shaft or the operation unit, the position of the operation unit can be accurately compared with when the movement of the operation unit was estimated based on the command value to the actuator. And so on, and can be safely controlled. In other words, when the motion of the operating unit estimated from the command value or the like to the servomotor is significantly different from the motion of the operating unit detected by the transmission shaft or the operating unit, it can be easily determined that some abnormality has occurred. The positioning device can be controlled safely. Further, by providing such a position detecting means, a redundant sensor system can be provided, and the reliability of equipment at the time of failure can be increased. Therefore, the position detecting means provided on the transmission shaft or the operating unit need not be limited to one, but may be plural. If multiple sensors are provided,
The reliability is improved accordingly.

An embodiment embodying the second invention of the present application will be described below. FIG. 4 shows a schematic configuration of the positioning device. In FIG. 4 as well, the parts already described are given the same reference numerals and the description thereof will be omitted. As shown in FIG. 4, in the positioning device of the present embodiment, the rotation of the output shaft 14 of the servomotor 11 is reduced to a predetermined number of rotations by the rotation speed reducer 30 and transmitted to the transmission shaft 25. Transmission shaft 2
5 is provided with an operation part (robot arm) 40 that operates integrally with the transmission shaft 25. The other end of the transmission shaft 25 has a position sensor 2 for detecting a change in the angle of the transmission shaft 25.
6 are provided. Then, the value detected by the position sensor 26 is sent to the control device 50, and the servo motor 11 is controlled based on this value. Here, in the device shown in FIG. 4, an encoder which detects an angle change of the transmission shaft is used as the position sensor 26. In addition, a device which detects the angle of a potentiometer, a resolver, etc., a tachogenerator, etc. Any method may be used, such as one that detects the angular velocity of the transmission shaft. That is, any physical quantity may be used as long as the physical quantity allows the position of the operation unit 40 to be determined from the detected value.

Next, the operation of the positioning device shown in FIG. 4 will be described with reference to the flowchart shown in FIG. As shown in FIG. 5, first, the control unit 50 issues a command to the servo motor 11 to rotate at a predetermined rotation speed (S1). This command causes the servo motor 11 to start rotating (S2). When the servo motor 11 starts rotating, the control unit 50 estimates the position and / or speed of the operating unit from the command value to the servo motor (S3). here,
The estimation is performed assuming that there is no lost motion or axis deflection. At the same time, a physical quantity related to the angle of the transmission shaft is detected by a position sensor 26 provided at the shaft end of the transmission shaft 25. The control unit 50 determines the operating unit 40 from the detected value.
Then, the position and / or speed of is determined (S4). Next, the control unit 50 compares the value estimated in S3 with the value determined in S4 (S5). That is, in the positioning device shown in FIG. 4, since the shaft deflection and the lost motion due to the rotary reduction gear 30 are present, the position of the operation unit 40 obtained in S3 and S4 differs by this value. Therefore, the control unit 5
0 corrects the command value to the servo motor 11 by the difference (S6). The steps from S1 to S6 are repeated until the operation section 40 is positioned at a predetermined position. Therefore, since the servomotor is controlled based on the value detected by the transmission shaft 25, the operation section 40 can be accurately positioned at a predetermined position. Further, in the positioning device shown in FIG. 4, since the speed and / or the position of the operating section 40 determined from the angle change of the transmission shaft 25 measured by the position sensor 26 and the like are monitored, it is possible to immediately determine at the time of a collision and to safely. Monitoring and control becomes possible.

In the positioning device shown in FIG. 4, the position sensor 26 is provided at the shaft end of the transmission shaft 25, but this is not always necessary. For example, as shown in FIG.
6 may be arranged. The operation of the positioning device in this case is the same as that shown in FIG. In the positioning device shown in FIGS. 4 and 6 described above, the servomotor 11 that drives the operation unit 40 is not provided with a position sensor such as an encoder that detects a change in the angle of the output shaft of the servomotor 11. As shown in FIG. 3, servo motor 11, brake 12, position sensor 13 serve as driving means for driving operation unit 40.
May be used. In this case, in the flow illustrated in FIG. 5, the position of the operation unit 40 in S <b> 3 is not estimated from a command value to the servomotor 11 but is estimated using a value detected from the position sensor 13. With this configuration, the servomotor 1 is relatively easily used because it is based not on the command value to the servomotor but on the actually measured angle change of the output shaft of the servomotor 11.
The command value of 1 can be corrected to an accurate value. Also,
With this configuration, the position sensors for controlling the operation unit 40 are provided at two locations, and the reliability can be improved because a redundant sensor system is configured. That is,
Even if one of the sensors fails, the servomotor 11 can be controlled by the other sensor. Also, the value of the position sensor 13 provided on the servo motor 11 and the value of the position sensor 26 provided on the output shaft end of the transmission shaft 25 can be used to determine the characteristics of the rotary speed reducer 30. 13
Can be learned so as to obtain the actual amount of rotation of the transmission shaft or the like from the value of Therefore, if such learning is performed, even if the position sensor 26 attached to the transmission shaft 25 fails, the accurate transmission shaft 25 taking into account the characteristics of the rotary reduction gear 30 from the value of the position sensor 13 of the servomotor 11 can be used. Since the amount of rotation is known, and the servomotor 11 is controlled based on this value, the servo motor 11 can be positioned at an accurate position.

In the positioning device shown in FIGS.
Although the case where the operation unit 40 has a mechanism that rotates integrally with the transmission shaft has been described, the second invention of this application
Is not limited to a mechanism that rotates integrally with the transmission shaft 25,
The mechanism may be such that the operation unit 40 as shown in FIG. 8 performs a linear motion. Also in this case, the same effect as the positioning device according to the above-described embodiment can be obtained. In this case, the position of the operation unit 40 may be directly detected by using a laser distance measuring device instead of the position sensor (encoder) 26.

As described above, the second invention of the present application is particularly effective when some error factor (power transmission mechanism such as a reduction gear, a gear, a chain, etc.) is interposed between the actuator and the transmission shaft. That is, since the position detection of the operating unit is performed directly by the transmission shaft or the operating unit, the command value of the actuator can be corrected from the actual position of the operating unit. etc)
Can be eliminated, and the positioning accuracy can be dramatically improved.

The first invention and the second invention of the present application described above.
In each of the embodiments of the present invention, only the case where the operating unit 40 linearly moves by the ball screw and the operating unit rotates integrally with the transmission shaft has been described. However, the present invention relates to a positioning method using various other mechanisms. It can also be applied to devices. For example, the present invention is also effective in a case where an operation section is positioned by a link mechanism. Further, as shown in each of the above-described embodiments, devices (brake, motor, position sensor, and the like) attached to the transmission shaft of the positioning device may be appropriately selected in accordance with the functions required for the positioning device. . For example, if a positioning force is required, such as when the positioning position shifts due to a large disturbance from the work robot, a brake may be attached to the transmission shaft.If the driving force is insufficient, a motor is provided. Good.

The above-described positioning device can be suitably used for a jig device which is disposed on a welding line for assembling an automobile and supports a work at a predetermined position, but is used in various other fields. For example, it can be used in a work station for positioning and inspecting a processed work.

[0026]

As described above in detail, according to the positioning device of the present invention, a work can be accurately positioned at a predetermined position.

[Brief description of the drawings]

FIG. 1 is a drawing showing a schematic configuration of a positioning device according to an embodiment of a first invention of the present application.

FIG. 2 is a drawing showing a modification of the positioning device shown in FIG.

FIG. 3 is a diagram showing a schematic configuration of a positioning device according to another embodiment of the first invention of the present application.

FIG. 4 is a drawing showing a schematic configuration of a positioning device according to an embodiment of the second invention of the present application.

5 is a drawing showing an operation flow of the positioning device shown in FIG.

FIG. 6 is a drawing showing a modification of the positioning device shown in FIG.

FIG. 7 is a drawing showing another modified example of the positioning device shown in FIG.

FIG. 8 is a drawing showing a schematic configuration of a positioning device according to another embodiment of the second invention of the present application.

FIG. 9 is a drawing showing a relationship between torque and shaft deflection generated in the shaft.

[Explanation of symbols]

 10 Servo motor module 11 Servo motor 12 Brake 13 Position sensor 18 Ball screw 19 Brake 26 Position sensor 40 Operating part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 7/106 H02K 7/106 // B23K 11/00 570 B23K 11/00 570 11/11 593 11/11 593A F term (reference) 3F060 AA05 DA07 GA13 GB19 GB25 GB26 GB33 GD07 GD13 4E065 CA01 5H303 AA04 AA10 BB01 BB06 BB07 BB11 BB17 CC01 CC09 DD01 DD03 DD24 DD25 DD27 EE07 FF06 FF20 GG20 HH02 FF20 BB20 DD FF01 FF33 HH01

Claims (3)

[Claims] 1. A positioning device for positioning and fixing an operation section at a predetermined position, comprising: an operation section, a transmission shaft for transmitting motion to the operation section, an actuator for driving the transmission axis, and the actuator. A positioning device comprising: a control device for controlling; and a braking unit provided on the transmission shaft and / or the operating unit, for braking movement of the operating unit. 2. A positioning device for positioning an operation section at a predetermined position, comprising: an operation section, a transmission shaft transmitting motion to the operation section, an actuator driving the transmission axis, and an angle of the transmission axis. A positioning device, comprising: a detecting unit that detects a physical amount or a physical amount related to the position of the operation unit; and a control device that controls the actuator based on the physical amount detected by the detecting unit. 3. A control method of an actuator for transmitting rotation of an actuator to an operation unit via a transmission shaft and positioning the operation unit at a predetermined position, wherein a command value to the actuator or an angle detected by the actuator is provided. Estimating the position of the operating unit from the physical quantities related to the transmission axis; detecting the position of the operating unit or directly detecting the position of the operating unit from the physical quantities related to the angle of the transmission axis detected by the transmission axis; Comparing the calculated value with an estimated value from the actuator, and correcting a command value to the actuator based on the difference.