JP2566997B2 - Non-contact positioning device - Google Patents

Description

The present invention relates to a positioning device capable of supporting and driving a driven body, and is capable of highly accurate and smooth positioning with multiple degrees of freedom. Equipment, space antenna pointing control device, optical equipment, semiconductor manufacturing equipment, etc.

(Prior Art) Conventionally, when performing positioning control of a plurality of degrees of freedom of a driven body, it is general to use a plurality of driving devices having a small degree of freedom in combination. As a driving method of such a positioning mechanism, a method of directly driving with a driving source such as a linear motor or a solenoid, or indirectly driving through a power transmission element such as a gear or a speed reducer is adopted. The driven body is supported by an oil bearing, a ball bearing, a spring, or the like.

Further, a sensor used to know the magnitude of the force to be generated from the driving device when positioning a plurality of degrees of freedom of the driven body also uses a combination of a plurality of sensors like the driving device. For example, when it is necessary to know the degree of freedom of rotation, information about the degree of freedom of rotation is obtained by a rotation angle system such as a magnetic encoder or an optical encoder or a rotation speed system represented by a tachometer. Alternatively, to detect the translational freedom information, use a displacement sensor such as an eddy current type, a linear scale, or an operating transformer, a speed sensor such as an optical type, or an acceleration sensor such as a piezoelectric effect or a semiconductor element to perform translational freedom. Get degree information.

However, the above positioning device has the following problems.

First, since a plurality of driving devices and sensors are combined, the structure is complicated, the number of parts is large, and it is difficult to manufacture and downsize.

Secondly, since friction occurs in each part during driving, heat is generated, the output changes, and friction causes instability, which makes it difficult to secure accuracy and reliability.

Thirdly, since the bearings that support the driven body need to slide, the service life cannot be reliable in a special environment such as high vacuum in space.

On the other hand, for example, there are those described in US Pat. No. 4,156,548 and US Pat. No. 4088018. This was designed for the purpose of supporting the telescope on the spacecraft away from the vibration of the spacecraft, and adding the optical axis correction. The disk is composed of 6 sets (12) of electromagnets from the outer periphery. It supports and realizes drive with 5 degrees of freedom. In this conventional example, the second and third problems are solved by adopting the non-contact support method.

However, in such a device, since two or more electromagnets are required for driving with one degree of freedom, a large number of electromagnets must be used for positioning with multiple degrees of freedom, and it is difficult to arrange them. There was a problem.

In order to reduce the number of electromagnets, Japanese Patent Application No. 61-12 describes a device for positioning a polyhedral driven body in a non-contact manner.
The applicant has already proposed the non-contact positioning device described in 059.

As shown in the perspective view of FIG. 6, this main structure is composed of a driven body 101 formed in a regular tetrahedron shape, and a driving means 103 for floating and driving the driven body 101 in a non-contact manner. .

Eight electromagnets 105, 107, 109, 11 which are the driving means 103
1, 113, 115, 117 and 119 are connected by a connecting member 121 made of a non-magnetic material, and an electromagnetic attraction force acts on the driven body 101 with a constant magnetic space.

A pillar 30 penetrating the hole 123 of the connecting member 121 is fixed to the center of the driven body 101, and an antenna (not shown) or the like is attached to the tip end side thereof. Therefore, positioning with 6 degrees of freedom is realized by using eight driving devices called electromagnets that generate a unidirectional force, and a great effect is obtained.

(Problems to be Solved by the Invention) As described above, in the prior art, when positioning with multiple degrees of freedom, a plurality of driving devices and sensors with few degrees of freedom are used in combination, so that the structure is complicated and the number of parts is large. However, it was difficult to manufacture and miniaturize. Therefore, the present applicant has already proposed Japanese Patent Application No. 61-12059 and obtained a great effect.

The present invention is a further development of the present invention, and an object of the present invention is to provide a non-contact positioning device which enables positioning with other degrees of freedom by using a smaller number of electromagnets and which can be downsized.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, in the present invention, a driven body to be positioned and a unidirectional one for supporting and driving the driven body. In a non-contact positioning device including a driving unit that generates a force and a sensor that detects the position and orientation of the driven body, the driven body has a substantially triangular main plate and three sides not parallel to the main plate. The driving means is provided at least one in the vicinity of the main plate side apex of each of the side plates, and a total of four drive means, and one each in the vicinity of the apex of the main plate. A total of three are arranged.

(Operation) In such a configuration, at least one drive means is provided near each apex of the main plate on the side of the main plate and a total of three drive means are provided, one near the apex of the main plate. Perform non-contact positioning.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall perspective view showing the configuration of a non-contact positioning device according to a first embodiment of the present invention. This non-contact positioning device includes a driven body 1 formed of a magnetic body to be positioned. , Electromagnets 3,5,7,9,11,13,15 composed of seven identical structures, which are driving means for supporting and driving the driven body 1 and generating a unidirectional force, It is composed of position detectors A3, A5, A7, A9, A11, A13 and A15 which are sensors having the same structure and which detect the position and orientation of the driving body 1.

The driven body 1 is, as shown in FIGS. 1 and 2, a regular tetrahedron main plate 17 having an equilateral triangle, and side plates having the same shape as the three main plates 17 which are not parallel to the main plate 17 and are in contact with three sides. 19,21,23
It is formed by.

A positioning shaft 25 is fixed to the surface of the main plate 17, and an object to be positioned, for example, an antenna (not shown) or an optical device is attached.

As shown in FIG. 2, the electromagnets 3, 5, 7, 9 serving as the driving means apply an electromagnetic attraction force with a certain magnetic space near the apex of the side plates 19, 21, 23 on the main plate 17 side. It is arranged.

The electromagnets 11, 13 and 15 are arranged near the apex of the main plate 17 with a constant magnetic space.

The position detectors A3, A5, A7, A9, A11, A13, A15 are main plates 17 and side plates 1 to which the electromagnets 3, 5, 7, 9, 11, 11, 13 and 15 face each other.
They are arranged at predetermined positions on the surface of 9, 21, 23 with a certain gap.

A connecting member 27 made of a non-magnetic material is provided around the driven body 1, and the electromagnet 3 is attached to the connecting member 27.
.About.15 and position detectors A3 to A15 are supported by unillustrated bolts or the like.

The electromagnets 3 to 15 have the same structure as shown in FIGS. 3 and 4, for example. Ie two yokes 29,3
It is formed of a ferromagnetic material including a coupling portion 33 that magnetically couples 1 and a coil 34 is wound around the yokes 29 and 31. Further, each of the coupling portions 33 is connected to the driven body 1 from the yokes 29, 31.
The position detectors A3 to A15 for detecting the air gap distance are fastened by nuts or the like.

Therefore, the driven body 1 includes the electromagnets 3 to 15 and the position detector.
It is not fixed with respect to A3 ~ A15 and can move freely within the drive range defined by the set position.
Reference numeral 25 denotes a hole penetrating a hole 27a provided in the connecting member 27.

The detection signals of the position detectors A3 to A15 are input to the position adjusting means 35 shown in FIG. 5, which supplies a current to each of the electromagnets 3 to 15 and controls them to adjust the position of the driven body 1. It has become like. The position adjusting means 35 is of a direct control type. That is, the external command signal given in the Cartesian coordinate system is distributed to the vector in the direction of each electromagnet 3 to 15 by the vector calculator 37, and the output signal from the vector calculator 37 and each electromagnet 3 to 15 are provided. The differences from the detection signals of the position detectors A3 to A15 are input to the controllers B3 to B15. In each of the controllers B3 to B15, the control amount according to the difference is calculated and output, and the control amount signal is amplified by the signal amplifiers C3 to C15,
The electromagnets 3 to 15 are configured to output an amplified signal.

Next, the operation of the first embodiment will be described with reference to FIG.

In FIG. 2, the electric current flowing through the electromagnet 5 is increased by the position adjusting means 35 shown in FIG. 5, and the other electromagnets 3, 7, 9, 1
By appropriately increasing or decreasing the current flowing through 1,13,15, the electromagnet 5
The magnetic force between the driven body 1 and the driven body 1 is strengthened, and movements other than in the X-axis direction caused by this magnetic force are caused by other electromagnets 3, 7, 9, 1.
By adjusting the magnetic force between 1, 13, 15 and the coated moving body 1, the driven body 1 is entirely moved in the direction of arrow Fx in the figure.

Similarly, by increasing the current flowing through the electromagnets 3, 5 by the position adjusting means 35 and appropriately increasing or decreasing the current flowing through the other electromagnets 7, 9, 11, 13, 15, the electromagnets 3, 5 and the driven body 1 are separated. The magnetic force between the driven bodies 1 is adjusted by adjusting the magnetic force between the electromagnets 7, 9, 11, 13, 13 and other driven magnets 1 and the movements other than the Y-axis direction caused by the magnetic force between the driven bodies. 1 moves in the direction of the arrow F _Y in the figure as a whole.

Further, by increasing the current flowing through the electromagnets 3, 9 by the position adjusting means 35 and appropriately increasing or decreasing the current flowing through the other electromagnets 5, 7, 11, 13, 15, the electromagnets 3, 9 and the driven body 1 are separated. Between the electromagnets 5, 7, 11, 13, 15 and the driven body 1 by adjusting the magnetic force between the other electromagnets 5, 7, 11, 13, 15 caused by the magnetic force to be driven. The body 1 generally rotates in the direction of arrow F _R in the figure.

Further, by increasing the current flowing through the electromagnets 11, 13, 15 by the position adjusting means 35 and appropriately increasing or decreasing the current flowing through the other electromagnets 3, 5, 7, 9 and the electromagnets 11, 13, 15 and the driven body. The magnetic force between the driven body 1 and the driven body 1 is adjusted by adjusting the movements other than the Z-axis direction caused by the magnetic force between the electromagnets 3, 5, 7, 9 and the driven body 1. The body 1 generally moves in the direction of arrow Fz in the figure.

In this way, the non-contact positioning device according to this embodiment is
The driven body 1 can be levitated by the total of seven electromagnets 3 to 15 and the total of seven position detectors A3 to A15 to perform arbitrary positioning. Especially for each near the top of the main plate 17
Since a total of three electromagnets 11, 13, 15 can be arranged one by one, it is possible to improve the levitation stability when an antenna or the like is attached, and to use an effective acting force when using it in a gravitational field, for example. Therefore, the operating efficiency is improved and the electromagnet can be downsized.

[Effects of the Invention] As is clear from the above description, according to the configuration of the present invention, the directions of the unidirectional forces generated by the driving means are non-orthogonal to each other, so that positioning with 6 degrees of freedom is performed with the minimum number of positions. It can be realized by seven driving means. Further, the device can be downsized and the weight can be reduced.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing the configuration of a non-contact positioning device according to a first embodiment of the present invention, and FIG. 2 is an arrangement configuration and operation of electromagnets and position detectors used in the non-contact positioning device of FIG. FIGS. 3 and 4 are schematic diagrams of the electromagnet, FIG. 5 is a block diagram of the position adjusting means, and FIG. 6 is a perspective view showing a conventional example. 1 …… Driven object 3,5,7,9,11,13,15 …… Electromagnet A3, A5, A7, A9, A11, A13, A15 …… Position detector (sensor) 17 …… Main plate 19,21 , 23 …… Side plate

Claims (1)

(57) [Claims] 1. A driven body to be positioned, a drive means for generating a unidirectional force for supporting and driving the driven body, and a sensor for detecting the position and orientation of the driven body. In the non-contact positioning device configured, the driven body is composed of a substantially triangular main plate and three side plates that are not parallel to the main plate and contact three sides, and the drive means is the apex of the side plates on the main plate side. A non-contact positioning device characterized in that at least one is provided in the vicinity of a total of four, and one is provided in the vicinity of the apex of the main plate for a total of three.