JPS6227601A - Absolute position detector - Google Patents

Abstract

PURPOSE:To make it possible to detect the absolute position without increasing detecting circuits even if the number of control shafts is increased, by using a selector circuit. CONSTITUTION:Position detectors (resolvers) 12, 13 and 14 (the resolver 12 is directly connected to a motor 10) are linked to the motor 10 through a gear transfer mechanism 11. Any one of the outputs P1-P3 on the secondary sides of the detectors 12-14 is selected by selecting signals SL1 and SL2 from a CPU 19 through a selector circuit 15 and the like. The selected signal is shaped 16 into a rectangular wave. The result is stored in a register circuit 17 as a latch signal. The selector circuit 15 is set so that only the output P1 of the secondary side of the circuit 12 (directly connected to the motor 10) by the CPU. The difference in data obtained by the circuit 17 is added to the obtained absolute value. Thus the present position is detected based on the absolute value.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to control axes of machine tools, etc., such as the x of a table,
The present invention relates to a device for directly detecting the absolute position of a control axis or the like that is subject to position control in the y direction.

[Background technology and its problems]

Conventionally, absolute position detection has been performed by sequentially reading position data obtained from multiple position detectors and calculating the absolute value by calculating the data using a central processing unit (CPU) or high-speed calculation circuit. However, a similar method was used to detect the movement distance of the control shaft when the motor rotated.

While this has the advantage of being able to read the current position as an absolute value, it has the disadvantage that as the number of control axes increases, a proportionate number of detection circuits are required and the failure rate also increases.

[Purpose of the invention]

An object of the present invention is to provide an absolute position detection device that can detect the absolute position without increasing the number of detection circuits even if the number of control axes increases.

[Means and actions for solving problems] Therefore,
The present invention includes a plurality of position detectors connected to the rotor of the motor via a gear transmission mechanism, at least one of which can detect an absolute angle within one revolution of the rotor, and a secondary side output from each of these position detectors. a selector circuit that selectively retrieves the position data, a detection circuit that has a storage section that updates and stores position data obtained based on the secondary output from the position detector selected by the selector circuit, and a storage section of the detection circuit. After sequentially importing the position data stored in the controller and calculating the absolute position from these position data, only the secondary output from the position detector that detects the absolute angle within one rotation of the motor rotor is selected. The present invention is characterized by comprising an arithmetic processing device that sets the selector circuit and adds a difference between the position data updated and stored in the storage section to the absolute position data to obtain the absolute position.

〔Example〕

FIG. 1 shows an embodiment of the invention. In the same figure, for example, the output shaft of a motor 10 that moves a table of a machine tool in one of a plurality of moving directions, here the X-axis direction, is connected to three position detectors via a gear transmission mechanism 11. The rotor shafts of IX resolvers 12, 13, and 14 are connected to each other. Here, only the IX resolver 12 is directly connected to the output shaft of the motor 10. Each resolver 1
2.13.14 The primary side excitation winding has an electric wire of 29°30
Excitation current (Sin wave, CO3
wave) is supplied.

Secondary side output P of each resolver 12, 13.14.

Pt and P3 are sent to the selector circuit 15 through electric wires 21, 22, and 23. The selector circuit 15 includes a central processing unit (hereinafter referred to as CPU) 19 as an arithmetic processing unit.
Select signal S given through wires 31 and 32 from
One of the outputs is selected by L, SL, and the selection signal is sent to the waveform shaping circuit 16 via the electric wire 24.

For example, when the select signals SL, SL, are both "0", the signal P is selected, and the select signal SL is "1".
” and the select signal S L z is “0”, the signal P2 is selected, and further, when the select signal SL is “0” and the select signal SL2 is rlJ, the signal P is selected.

The waveform shaping circuit 16 shapes the obtained signal into a rectangular wave and supplies it as a latch signal to the register circuit 17 as a storage section via the electric wire 25.

The register circuit 17 is supplied with data of a self-running counter 18 in base 2000 through a line 26.
The data in the counter 18 is set by the aforementioned latch signal. The data sent to the register circuit 17 is read out from the CPU 19 via the electric wire 2.
When the signal is applied to the register circuit 17 through the line 27, it is taken into the CPU 19 through the line 27. Note that here, the waveform shaping circuit 16, the register circuit 17, and the counter 18 constitute the detection circuit 41 of this embodiment.

The CPU 9 outputs a successive signal Rd, and among the data set in the register circuit 17, the value from the resolver 12 is a2, the value from the resolver 13 is as, and the value from the resolver 1 is
Let the value from 4 be a3, and calculate the absolute value A corresponding to the motor rotation using the following relational expression.

A” (al, az, a3) (0≦ai≦1999) After this, in the CPUI 9, only the secondary side output of the resolver 12 (the secondary side output of the resolver 12 directly connected to the motor IO) is The selector circuit 15 is set to select, and the difference in data obtained from the register circuit 17 is added to the determined absolute value A, thereby detecting the current position as an absolute value.

In the above description, an example is shown in which an IX resolver is used as a position detector, but the present invention is not limited to simply a resolver as long as the absolute amount within one rotation can be measured. For example, an inductosin or magnetic scale may be used.

Further, the configuration of the detection circuit 41 is not limited to the configuration including the waveform shaping circuit 16, counter 18, and register circuit 17 described in the above embodiment, but may be a detection circuit 91 as shown in FIG. This is the excitation circuit 60
The fundamental periodic signal fo (excitation signal: Sin, C
os wave) and the rectangular wave signal f obtained from the waveform shaping circuit 56, a pulse corresponding to the phase difference is sent to the up/down counter 5.
8, and finally selects only the secondary output of the resolver 52, which is the same as in FIG.

〔Effect of the invention〕

As described above, according to the present invention, by using the selector circuit, even if the number of control axes increases, the absolute position can be detected without increasing the number of detection circuits.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the invention, and FIG. 2 is a block diagram showing another embodiment of the invention. 10.50...Motor, 11.51...Gear transmission mechanism, 12,13,14.52.53.54...Resolver as position detector, 15.55...Selector circuit, 16. 56... Waveform shaping circuit, 17... Register circuit as storage section, 18... Counter, 58...
Counter as storage unit, 19.59... CPU as arithmetic processing unit, 20.60... Excitation circuit, 57.
...Phase synchronization circuit. Representative Patent Attorney Minoru Kinoshita Figure 1 Figure 2

Claims (4)

[Claims] (1) A plurality of position detectors connected to the rotor of the motor via a gear transmission mechanism, at least one of which can detect an absolute angle within one rotation of the rotor, and a secondary side output from each of these position detectors. A detection circuit having a selector circuit for selectively extracting data, a storage section for updating and storing position data obtained based on the secondary output from the position detector selected by the selector circuit, and a storage section for the detection circuit. After sequentially importing the stored position data and calculating the absolute position from these position data,
The selector circuit is set to select only the secondary output from the position detector that detects the absolute angle within one revolution of the motor rotor, and the difference between the position data updated and stored in the storage unit is used as the absolute value. An absolute position detection device characterized by comprising: an arithmetic processing device that calculates the absolute position by adding it to position data; (2) In claim 1, the position detector is configured by a plurality of unipolar resolvers connected to the rotor of the motor via a gear transmission mechanism. Detection device. (3) In claim 2, the detection circuit includes a waveform shaping circuit that shapes the secondary output from the resolver selected by the selector circuit into a rectangular wave, and a self-running counter; An absolute position detection device comprising: a register circuit that latches data of the counter using an output from the waveform shaping circuit as a latch signal. (4) In claim 2, the detection circuit includes a waveform shaping circuit that shapes the secondary output from the resolver selected by the selector circuit into a rectangular wave, and an output from the waveform shaping circuit. and a phase synchronized circuit that outputs a pulse corresponding to the phase difference between the excitation signal supplied to the primary side of the resolver and a rectangular wave signal of the same period, and an up/down counter that counts the pulses from this phase synchronized circuit. An absolute position detection device characterized by comprising: