JPH06323803A - Position detector for moving body - Google Patents

Abstract

PURPOSE:To provide a general purpose position detector for moving body in which highly accurate noncontact positional detection of a moving body can be realized at all times while enhancing the durability of the entire detector. CONSTITUTION:The positional detector for moving body comprises a fixed member 1 disposed along the moving direction of a moving body 2, a fixed exciting coil 3 mounted on the fixed member 1 with the open face thereof directing substantially in parallel with the moving direction of the moving body 2, an AC signal output section 5 for driving the fixed exciting coil 3, and an annular coil 7 to be excited mounted on the moving body 2 while opposing the open face of the fixed exciting coil with the open face of the coil 7 directing substantially in parallel with the moving direction of the moving body 2. Furthermore, an annular positional detection coil 8 is disposed on the fixed member 1 side while being coupled magnetically with the coil 7 having the opposite ends connected each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for a moving body, and in particular, it can drive and control a moving element that reciprocates within a limited area and simultaneously detect its position. The present invention relates to a position detecting device for a moving body.

[0002]

2. Description of the Related Art For example, with the recent development of computers, there has been a great demand for mobile device position detection devices for peripheral devices thereof. Especially for the position detection system of a moving element in a linear motor or the like, which can drive and control the moving element that reciprocates within a limited area at the same time, Initially, development has been undertaken in various fields, but most of them are connected to an external power source or the inside of the mover in order to secure the power supply for driving the control circuit in the mover. A method of incorporating a battery or the like into the is adopted.

[0003]

However, the conventional one in which the battery is incorporated in the moving element hinders the miniaturization of the moving element, and the one to which the external power source is connected is apt to cause a disconnection accident. Therefore, there is a problem that durability is difficult and versatility is lacking.

[0004]

An object of the present invention is to improve the inconveniences of the prior art, particularly to detect the position of the moving body without contact at all times with high accuracy, and to improve the durability of the entire apparatus. It is an object of the present invention to provide a position detecting device of the above.

[0005]

According to the present invention, a fixing member is provided so as to face a moving body, and an opening surface of the fixing member provided in the fixing member is substantially parallel to the moving direction of the moving body. The fixed excitation coil that has been set, an alternating signal oscillating circuit that drives this fixed excitation coil, and a moving body that is provided facing the opening surface of the fixed excitation coil and that is parallel to the moving direction of the moving body. And an annular excited coil set so that An annular position detection coil that is magnetically coupled to the excited coil is provided on the fixed member side, and both ends of the excited coil are connected to each other. This aims to achieve the above-mentioned object.

[0006]

[Operation] First, set the entire device to the operating state. In this case, the alternating magnetic fluxes simultaneously output from the fixed exciting coil are linked to the excited coil on the moving body side to induce a current in the excited coil according to the amount of the linked magnetic flux.

Due to the current generated in the excited coil, a secondary alternating magnetic flux having a magnitude corresponding to the current is generated from the excited coil. The secondary alternating magnetic flux is linked to the position detection coil on the stator body side, and an induced electromotive force having a magnitude corresponding to the amount of the linked magnetic flux is output to the output end of the position detection coil. The value of the voltage signal from the excited coil obtained by this position detection coil has a magnitude corresponding to the amount of secondary alternating magnetic flux that the position detection coil receives from the excited coil.
In this way, the position information of the moving element is constantly and effectively captured in real time by the position detection coil.

Next, even when the mobile body moves in the opposite direction to the previous one, the position information of the mobile body is constantly and effectively captured in real time by the position detection coil under the same situation. It

[0009]

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. In the first embodiment shown in FIGS. 1 to 3, the fixing member 1 is provided along the moving direction of the moving body 2.
Is provided. The fixed member 1 has an annular fixed excitation coil 3 formed in a quadrangle along an opening surface of the fixed member 1 which is set to be substantially parallel to the moving direction of the moving body 2.
And an alternating signal oscillating circuit 5 for exciting and driving the fixed exciting coil 3.

Further, the moving body 2 is equipped with an annular excited coil 7 which faces the opening surface of the fixed exciting coil 3 and whose opening surface is substantially parallel to the moving direction of the moving body 2. It is like this. Both ends of the excited coil 7 mounted on the moving body 2 are connected to each other through a predetermined resonance capacitor 9 that resonates in parallel with the excited coil 7.

As a result, a relatively large resonance current is efficiently generated in the excited coil 7 by the alternating magnetic flux for position detection output from the fixed excitation coil 3 and is constantly flowing. There is. On the other hand, the resonance current generated in the excited coil 7 always outputs the alternating magnetic flux having the same frequency to the outside (that is, the fixed member 1 side).

Further, the fixed member 1 is equipped with an annular position detection coil 8 which is magnetically coupled to the excited coil 7. Therefore, the position detection coil 8 is fixed to the fixed excitation coil 3
The alternating magnetic flux for position detection output from is always received, and at the same time, the alternating magnetic flux of the same frequency output from the excited coil 7 on the mover 2 side is always received.

In this embodiment, the position detecting coil 8 is composed of a pair of detecting coil portions 8A and 8B having a plurality of turns. At the same time, the detection coil portions 8A and 8B are arranged parallel to the surface of the fixed exciting coil 3 and along the moving direction of the moving element 2. Therefore, the alternating magnetic flux output from the excited coil 7 described above can be reliably captured by either of the detection coil units 8A and 8B even if the mover 2 moves.

On the other hand, the fixed excitation coil 3 is, in relation to the above-mentioned detection coil portions 8A and 8B, at a position where it is magnetically coupled uniformly to a part of the detection coil portions 8A and 8B as shown in FIG. It is arranged. Further, the position detection coils 8 are connected to each other in opposite polarities.

For this reason, the amount of interlinkage magnetic flux that the position detecting coil 8 receives from the fixed exciting coil 3 depends on each detecting coil portion 8A,
8B always has the same amount, and therefore is canceled in the position detection coil 8. As a result, the output of the position detection coil 8 is interlinked with the alternating magnetic flux output from the excited coil 7 described above in a state where it is not affected by the fixed excitation coil 3 at all. The position information of the moving element 2 can be output as a voltage signal of a predetermined level corresponding to the interlinkage magnetic flux, for example, as V _A and V _B in FIG.

Reference numeral 11 indicates a synchronous detection circuit for inputting the output of the position detection coil 8 for synchronous detection and outputting, and reference numeral 14 indicates a starting switch. Further, reference numeral 15 indicates a current value variable setting unit for variably setting the current value of the DC power supply 13 applied to the fixed excitation coil 3. FIG. 2 shows an example of the positional relationship between the coils in the above embodiment.

Next, the operation of the above embodiment will be described.

Here, it is assumed that the moving body 2 is moving in the direction of arrow A in FIG. First, the start switch 14 is turned on to set the entire apparatus to the operating state. In this case, the alternating magnetic flux output from the fixed exciting coil 3 links the excited coil 7 on the moving body 2 side and induces a relatively large resonance current in the excited coil 7 according to the amount of the interlinking magnetic flux. Let In this case, the position detection coil 8 on the fixed member 1 side also receives an alternating magnetic flux from the fixed excitation coil 3 to generate a predetermined induced electromotive force, but as described above, the reverse polarity coupling of the detection coil units 8A and 8B is performed. Offset by.

Due to the resonance current generated in the excited coil 7, a secondary alternating magnetic flux having a magnitude corresponding to the resonance current is generated from the excited coil 7. This secondary alternating magnetic flux is linked to the position detection coil 8 on the side of the fixed member 1, and an induced electromotive force having a magnitude corresponding to the amount of the linked magnetic flux is applied to the output end of the position detection coil 8 as described above. It is output as _AB (see FIGS. 1 and 3). The value of the voltage signal obtained by the position detection coil 8 has a magnitude corresponding to the amount of the secondary alternating magnetic flux that the position detection coil 8 receives from the excited coil 7.

In this way, the position information of the moving body 2 in the direction of arrow A in FIG. 2 is constantly and effectively captured by the position detecting coil 8 in real time.

Next, the moving body 2 is moved to the right in FIG.
Consider the case of moving in the direction. Also in this case, the alternating magnetic flux output from the fixed exciting coil 3 is linked to the excited coil 7 on the moving body 2 side, and in the excited coil 7 according to the amount of the linked magnetic flux, as in the case described above. Induces a relatively large resonance current. In this case, the position detection coil 8 on the side of the stator body 1 also receives the alternating magnetic flux from the fixed excitation coil 3 to generate a predetermined induced electromotive force, but as described above, the reverse polarity of the detection coil portions 8A and 8B is generated. Offset by combination. Hereinafter, as in the case described above, each part operates, and the position information of the moving body 2 in the direction of arrow B in FIG.
It is effectively and surely always captured in real time. An example of the position data captured and output by the position detection coil 8 is shown in FIG.

Then, as described above, the position detecting coil 8
The position data of the moving element 2 captured by is synchronously detected by the synchronous detection circuit 11, linearity is improved, and output to the outside. FIG. 6 shows an example of measuring the position information of the moving element 2 in the first embodiment output from the synchronous detection circuit 11.

As described above, in the first embodiment,
Only by equipping the moving body 2 with the excited coil 7 and the resonance capacitor 9 that are connected in parallel and form a closed circuit, the position information of the moving body 2 can be effectively and accurately captured from the fixed member 1 side. At the same time, by the action of the resonance capacitor 9, a resonance current can be effectively generated in the excited coil 7, and the influence of the external magnetic field deviated from this resonance point is almost 1
00% can be eliminated, and thus the S / N ratio can be effectively improved, and the positional information of the moving body 2 can be fixed without any external wiring to the moving body 2 and without contact. Since it can be captured on the one side and is configured and functions as described above, it is possible to obtain an advantage that the entire device can be downsized and durability and reliability of the entire device can be improved. it can.

Here, in the above-described embodiment, the case where the two detection coil portions 8A and 8B are used as the position detection coil 8 has been illustrated, but this is relatively large in the opening surface with respect to the fixed excitation coil 3 described above. It may be composed of a large single detection coil unit 8A or 8B. In this case, it is convenient to set the detection coil unit 8A or 8B and the fixed excitation coil 3 so that their axes are on the same line.

Further, in this case, a single detection coil unit 8A
Alternatively, by arranging the fixed excitation coil 3 with the same central axis inside 8B, it is possible to reduce the overall thickness of the position detection coil 8 and the fixed excitation coil 3 portion, which is convenient. At the same time, it is convenient that the detection coil section 8A or 8B and the above-described excited coil 7 have substantially the same opening surface size.

FIG. 4 shows a modification of FIG. In the modification shown in FIG. 4, the detection coil units 8A and 8B shown in FIG.
It is characterized in that the above-mentioned fixed exciting coil 3 is arranged between A and 8B. Other configurations are shown in FIG.
It is the same as that of the embodiment.

Even in this case, the same effect as that of the embodiment shown in FIG. 1 can be obtained.

[0028]

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. Here, the same components as those in the embodiment shown in FIG. 1 described above are designated by the same reference numerals.

In the second embodiment shown in FIGS. 7 to 8, the fixing member 11 is arranged along the moving direction of the moving body 2 as in the embodiment shown in FIG. This fixing member 11
Is an annular fixed excitation coil 3 formed in a quadrangle along an opening surface of the fixed excitation coil 3 which is set to be substantially parallel to the moving direction of the moving body 2, and an alternating signal for exciting and driving the fixed excitation coil 3. It is equipped with an oscillation circuit 5.

The movable body 2 is provided with a pair of excited coils 27A and 27B of the same size, which are formed in an annular shape facing the opening surface of the fixed exciting coil 3 and are spaced apart from each other by a predetermined distance. ing. The opening surfaces of the excited coils 27A and 27B are set to be substantially parallel to each other along the moving direction of the moving body 2.

Excited coil 2 mounted on this moving body 2
7A and 27B are connected in series with opposite polarities, and at the same time, the output ends of the excited coils 27A and 27B are connected to each other via a predetermined resonance capacitor 29 that resonates in parallel with the entire excited coils 27A and 27B. There is.

As a result, the excited coils 27A, 27
In B, a relatively large resonance current is efficiently generated by being constantly energized by the alternating magnetic flux for position detection output from the fixed excitation coil 3 described above. On the other hand, the resonance current generated in the excited coils 27A and 27B generates an alternating magnetic flux having the same frequency to the outside (that is, the fixing member 1).
Side) will always be output.

Further, the fixed member 1 has an excited coil 27.
A single position detection coil 28, which is formed in an annular shape and is magnetically coupled to A and 27B, is provided. Therefore, the position detecting coil 28 always receives the position-detecting alternating magnetic flux output from the fixed excitation coil 3, and at the same time, the moving body 2 described above is received.
The alternating magnetic fluxes of the same frequency output from the excited coils 27A and 27B on the side are always received. Further, in this case, if the fixed excitation coil 3 is arranged inside the single position detection coil 28 with the same central axis, the overall thickness of the position detection coil 28 and the fixed excitation coil 3 portion can be reduced. It is convenient to do this.

In the second embodiment shown in FIGS. 7 to 8, since the position detecting coil 28 is composed of a single coil having a plurality of turns, the position detecting coil 28 outputs from the excited coils 27A and 27B. The change in the magnetic flux of the position information is detected in a state of being overlapped with the amount of interlinking magnetic flux with the fixed excitation coil 3 described above, and is output as a voltage signal. Therefore, the information separation detection circuit 30 separates and outputs the position information from the excited coils 27A and 27B. The other structure is the same as that of the embodiment shown in FIG.

Even in this case, the function and effect are almost the same as those of the first embodiment described above.

In each of the above-mentioned embodiments, particularly the excited coil 7
(Or 27A, 27B) to the resonance capacitor 9 (or 2
9) is connected in parallel, the excited coil 7 (or 27) is used without using the resonance capacitor 9 (or 29).
Both ends of A, 27B) may be directly connected and used.
In this case, the other functions similarly with only a decrease in sensitivity. Further, in each of the above embodiments, the case where each coil is formed in a quadrangle is disclosed, but the shape of each coil may be circular, for example.

[0037]

Since the present invention is constructed and functions as described above, according to the present invention, the position of the moving body can be accurately adjusted in real time without contact by simply equipping the moving body with the excited coil. Since it is possible to always specify, it is not necessary to load the battery to the moving body and wiring from the outside to the moving body, so that the durability and reliability of the entire device can be significantly improved, and at the same time, the entire equipment can be identified. It is possible to provide an excellent general-purpose position detecting device for a moving body, which has not been available in the past and can be downsized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship of each coil disclosed in FIG.

3 is an operation explanatory diagram of FIG. 1, and is a diagram showing a case where the moving element disclosed in FIG. 1 is moving in one direction or the other direction.

FIG. 4 is an explanatory diagram showing a modified example of the embodiment shown in FIG.

5 is a diagram showing a measurement example of position information of a moving element output from a position detection coil in the embodiment shown in FIG. 1. FIG.

FIG. 6 is a diagram showing an example of measurement of position information of a mover output from the synchronous detection circuit in the embodiment shown in FIG.

FIG. 7 is an overall configuration diagram showing a second embodiment.

FIG. 8 is an explanatory diagram showing a positional relationship of each coil disclosed in FIG.

[Explanation of symbols]

 1 fixed member 2 moving body 3 fixed excitation coil 5 alternating signal output section 7, 27A, 27B excited coil 8, 28 position detection coil 8A, 8B detection coil section 9, 29 resonant capacitor 11 synchronous detection circuit

Claims (8)

[Claims] 1. A fixing member which faces a moving body and is arranged along a moving direction of the moving body, and an opening surface of the fixing member which is provided on the fixing member and is substantially parallel to the moving direction of the moving body. Fixed exciter coil set to, an alternating signal oscillation circuit for driving this fixed exciter coil, and an opening surface of the fixed exciter coil facing the opening surface of the moving body, the opening surface being in the moving direction of the moving body. An annular excited coil set so as to be substantially parallel, and an annular position detection coil magnetically coupled to the excited coil is provided on the fixed member side, and both ends of the excited coil are mutually connected. A position detecting device for a moving body, characterized in that the position detecting device is connected to the. 2. A fixing member which faces the moving body and is arranged along the moving direction of the moving body, and an opening surface of the fixing member which is provided on the fixing member and is substantially parallel to the moving direction of the moving body. Fixed exciter coil set to, an alternating signal oscillation circuit for driving this fixed exciter coil, and an opening surface of the fixed exciter coil facing the opening surface of the moving body, the opening surface being in the moving direction of the moving body. An annular excited coil set to be substantially parallel, and an annular position detection coil magnetically coupled to the excited coil is provided on the fixed member side, and both ends of the excited coil are predetermined. A position detecting device for a moving body, characterized in that they are connected to each other via the resonance capacitor. 3. The position detecting device for a moving body according to claim 1, wherein the excited coil is formed of a single coil having a plurality of turns. 4. The excited coil is composed of a plurality of coils of a plurality of turns, and each coil is arranged along a moving direction of the moving body. The position detecting device for a moving body according to 1 or 2. 5. The position detecting device for a moving body according to claim 1, wherein the annular position detecting coil is composed of a single coil having a plurality of turns. 6. The annular position detection coil is composed of a plurality of two detection coil portions, and each detection coil portion is arranged along a moving direction of the moving body and has a reverse polarity connection. The position detecting device for a moving body according to claim 1, 2, 3, or 4, wherein: 7. The position detecting device for a moving body according to claim 6, wherein the fixed excitation coil is arranged at a position where it is magnetically coupled uniformly to each of the detection coil portions. 8. The fixed exciting coil is arranged between the respective detecting coil portions while arranging the respective detecting coil portions at a predetermined distance from each other.
A position detecting device for a moving body according to the item.