JPH0483118A - Multiple rotation detecting rotary encoder - Google Patents

Abstract

PURPOSE:To precisely synthesize rotating number with rotating angle by building up and falling the output of the counter of a multiple rotation detecting part synchronously with the fall timing of the top column of a rotary encoder. CONSTITUTION:A reset signal to a rotating number counter part 94 and a control signal are transmitted from a rotary encoder converter to a circuit base by a cable through terminals 211, 201 and through terminals 213, 203, respectively. On the other hand, the rotating number converted to serial signal, the absolute value of rotating angle similarly converted to serial signal, a timing signal, and a two-phase inclement pulse are transmitted from the circuit base to the rotary encoder converter by the cable through terminals 202, 212, through terminals 204, 214, through terminals 205, 215, and through 206, 207, 216, and 217, respectively. Thus, even if the detecting precision of a multiple rotation detecting part is such that one rotation of a rotating shaft can be recognized, the same precision as the time of detecting one rotation by the rotary encoder can be kept.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-rotation detection rotary encoder that simultaneously detects the number of rotations and rotation angle of a rotating shaft.

[Prior Art] A rotary encoder is well known as a detector that detects the rotation angle of a rotating shaft using an n-bit digital signal.

However, in a rotary encoder, the digital signal returns to its original value every time the rotary shaft rotates once, so it is not possible to count the number of rotations of the rotary shaft.

Therefore, when it is necessary to simultaneously detect the rotation angle and the number of rotations of the rotating shaft, a method has been used in which a reduction gear is provided on the rotating shaft and a mechanical counter is counted up every rotation.

However, in this method, it is difficult to precisely match the timing of one revolution of the rotary encoder and the count-up of the mechanical counter due to backlash existing in the reduction gear and the mechanical counter. Furthermore, the device is quite large, which causes some inconvenience in handling.

In order to solve these problems, we have developed a multi-rotation detection disk that outputs the reference position of the rotating shaft in a rotary encoder, and two sensors that detect the reference position generated from this disk as two-phase pulses with a phase shift. A method has been proposed in which a multi-rotation detector is installed to count up or down these two-phase pulses depending on the direction of rotation to count the number of rotations (Japanese Patent Application No. 1-305314).
.

[Problem B to be solved by the invention] However, in this method, it is necessary to arrange two sensors so that the second pulse rises while the first pulse is on. There is.

Therefore, in order to detect the reference position of the rotating shaft with high precision, it is necessary to attach and adjust the sensor with high precision.

Furthermore, since the most significant digit of the rotation angle of the rotary encoder must always be in a leading phase with respect to the least significant digit of the counter of the multi-rotation detector, there is a limit to the rotation angle of the rotary shaft that can reset the counter of the multi-rotation detector. there were.

Furthermore, if a counting error occurs once in the counter that counts the number of rotations, the error will be held until the counter is reset.

The present invention was made in view of the above problem, and even if the accuracy of the multi-rotation detection mechanism is high enough to distinguish between one rotation, the single rotation detected by the encoder and the multi-rotation detection mechanism cannot be detected. can be accurately synthesized with one rotation,
It is an object of the present invention to provide a multi-rotation detection rotary encoder that makes it possible to reset a rotation number counter at any rotation degree.

Another object of the present invention is to add a function to detect a signal indicating the occurrence of a count error in the counter of the multi-rotation detection mechanism.

[Means for Solving the Problems] The basic configuration of a multi-rotation detection rotary encoder according to the present invention is shown in FIG.

That is, there is a disk 100 on which a different pattern is formed every half rotation of the rotating shaft, and a first disk that detects the pattern on the disk.
detection means 101, the output of the first detection means 101, and 9.
a second detection means 102 that obtains outputs that are out of phase by 0°;
A rotation count means 103 that counts the number of disk rotations based on the outputs of the first and second detection means 101 and 102, a rotary encoder 104 that shares a rotation axis with the disk 100, and a rotation count means 10.
Logic signal value of the least significant digit (LSBcnt) of 3 and the most significant digit (MSBenc) of the output of the rotary encoder 104
A logical product calculating means 105 calculates a logical product with a negative value of a logical signal value, and the output of the logical product calculating means 105 and the digit one or more higher than the least significant digit (LSBcnt) of the counting means. A synchronous addition means 106 that performs synchronous addition to synchronize the rising and falling timing of the output of the rotation number counting means 103 with the falling timing of the output of the rotary encoder 104, and the rotation number counting means 1.
An initial value is set in the rotation count means 103 so that when a reset signal is applied to the rotation count means 103, the phase of the output of the second detection means 102 matches the phase of the output of the least significant digit of the rotation count means 103. Initial value setting means 107
and.

Further, a count error detection means (108) is provided which detects that a count error has occurred in the counter when the output of the second detection means 102 and the logical signal value of the least significant digit of the rotation number counting means 103 do not match. establish.

[Operation] In the multi-rotation detection rotary encoder configured in this way, even if the accuracy of the multi-rotation detection mechanism is at a level that can distinguish one rotation, it is impossible to synchronize with the fall timing of the most significant digit of the rotary encoder. Since the output of the counter of the multi-rotation detection section is raised and lowered by the rotation angle, it is possible to accurately synthesize the number of rotations and the rotation angle, and to reset the number of rotations counter at an arbitrary position.

Furthermore, even if a count error occurs in the counter of the multi-rotation detection mechanism, the occurrence can be quickly detected.

[Embodiment] A multi-rotation detection rotary encoder that is an embodiment of the present invention, which is a combination of a multi-rotation detection mechanism using a magnetic ring and a magnetic sensor, and an optical hybrid encoder, will be described below with reference to the drawings.

The hybrid encoder used here detects the rotation angle of the rotating shaft by dividing it into 2" = 32768, and outputs a 15-bit digital signal. The upper 8 bits are detected as an absolute signal, and the lower 8 bits are incremented. Detected as a signal.

FIG. 2 is a side sectional view of a hybrid encoder incorporating a multi-rotation detection mechanism according to this embodiment, and FIG. 3 is an enlarged view of the Y section, which is housed in a housing 1 consisting of a main body 11 and a cover 12. has been done.

A shaft 3 having a coupling 2 at the outer tip of the housing 1 protrudes from the cover 12, and this shaft 3 is connected to the cover 12.
It is supported by a bearing 13 attached to and connected via a coupling 2 to the rotation angle measurement target.

At the tip of this shaft 3 inside the housing 1 is a rotation angle detection disk 4.
A disk for detecting the number of rotations is attached and rotates together with the rotating shaft.

This rotation angle detection disk 4 has an absolute pattern for outputting the absolute value of the rotation angle, an increment pattern for outputting pulses corresponding to the rotation of the rotation axis, and an absolute signal and an increment pattern as described later. A timing signal generation pattern is formed to generate a timing signal for combining the signals.

A plurality of light emitting elements 5 and light receiving elements 6 are installed on both sides of the rotation angle detection disk 4 in a number corresponding to the absolute pattern, increment pattern, timing signal generation pattern, and light amount correction track.

Further, a fixed slit 7 is fixedly installed in the housing 1 between the rotation angle detection disk 4 and the light receiving element 6.

The rotation number detection disk 9 has a ring shape with half of the ring magnetized as a N pole and the other half as a S pole, and is opposed to the rotation number detection disk 9 at an angle of about 90'' to each other. Two magnetic sensors 91 and 92 are arranged.

Further, the housing 1 houses a circuit board 8 equipped with an electronic circuit for executing signal processing to be described later.

The output from the hybrid encoder housing 1 is transmitted to the hybrid encoder converter 3 via the cable 20.
Transmitted to 0.

FIG. 4 is a diagram showing a pattern formed on the disk 4. As shown in FIG.

That is, on the outermost periphery of the rotation angle detection disk 4, there is an incremental pattern 4 consisting of slits arranged at equal intervals.
1 is formed.

Note that the increment signal is detected as two signals having a phase shift of 90@ from each other in order to determine the rotation direction.

A timing signal generation pattern 42 for generating a timing signal used to synthesize the absolute signal and the increment signal is formed inside the increment pattern.

An absolute signal generation pattern 44A-4 for generating an 8-bit rotation angle absolute signal is provided inside the first light amount correction track 43A formed inside the first light amount correction track 43A.
4H is formed.

Note that a second light amount correction track 43B is also formed between the absolute signal generation patterns 44D and 44E.

Further, in this embodiment, it is assumed that the absolute signal generation pattern is formed so as to output a digital signal expressed in a gray code.

FIG. 5 is a diagram showing the functions of a circuit board 8 housed in the housing 1 for signal processing and a rotary encoder conversion device 300 connected to it via a cable 20.

That is, in order to make the amount of light emitted from the light emitting element 5 constant, the circuit board 8 detects the amount of light passing through the two light amount correction tracks 43A and 43B with the light receiving element 6, and calculates the amount of light emitted from the light emitting element 5. A light amount correction function 81, a first amplification section 82 that amplifies the signal received by the light receiving element 6, and a parallel-serial signal conversion section 83 that converts the 8-bit parallel signal detected by the absolute pattern into a serial signal. A second amplifying section 93 that amplifies the output of the magnetic sensor 91,92, a counter section 94 that counts the number of rotations based on the output of the amplifying section 93, and a second parallel-serial that converts the parallel output of the counter section into a serial signal. Conversion section 95, counter section 94 based on the reset signal
An initial value setting section 96 that sets a reset value to , a count error detection section 97 that detects a count error from the output of the second magnetic sensor 92 and the count value of the counter section, and a connection with the rotary encoder conversion device 30 via the cable 20 . A line receiver receiver unit 84 is included that adjusts the state of signals exchanged between the lines.

The rotary encoder conversion device 30 includes a cable 20
A line receiver receiver unit 301 adjusts the state of signals exchanged with the circuit board 8 via a first serial-parallel signal that converts the absolute value of the rotation angle transmitted as a serial signal into a parallel signal. Conversion section 30
2. An increment counter 303 that counts pulses detected by an increment pattern, an increment value latch unit 304 that latches the output of the increment counter 303, and a second unit that converts the number of rotations transmitted as a serial signal into a parallel signal. The serial-parallel signal converter 305 converts the absolute value of the rotation angle expressed in the 8-bit parallel Gray code format output from the first serial-parallel signal converter 302 into the absolute value expressed in the 8-bit parallel binary code. A data processing unit 306 that converts into a value and temporarily stores the output of the second serial-parallel signal converter, and a data latch that latches the final output of 15-bit data of the number of rotations and rotation angle of the rotating shaft. 307 and parallel-serial signal converters 83 and 95, serial-parallel signal converters 302 and 305, increment value latch unit 304, and a control signal generator 307 that generates a control signal to control the timing of data latch unit 305. It will be done.

It is then interfaced with the outside via a connector 309 attached to the rotary encoder converter.

A reset signal for the rotation number force absorber section 94 is sent to terminal 2.
11 and terminal 201, control signals are transmitted from rotary encoder converter 30 to circuit board 8 by cable 20 via terminals 213 and 203.

Conversely, the number of rotations converted into a serial signal is sent to the terminal 202.
The absolute value of the rotation angle, which is also converted into a serial signal, is sent to terminals 204 and 214 via terminal 204 and terminal 212.
The timing signal is passed through terminal 205 and terminal 215, and the two-phase increment pulse is passed through terminal 205 and terminal 215, respectively.
06. Cable 2 via 207 and 216 and 217
0 from the circuit board 8 to the rotary encoder converter 30.

FIG. 6 shows how the rising and falling timing of the output of the multi-rotation counter section can be controlled by the rotary encoder according to the present invention.
A functional diagram for explaining the operation to synchronize with rotation, and FIG. 7 is a timing diagram thereof.

That is, the counter section 94 of the circuit board 8 has two magnetic sensors 9.
a rotation direction determination unit 941 that determines the rotation direction of the rotation axis from 1 and 92 and instructs an up/down counter 943 to count up or count down; and a clock pulse generation unit that outputs clock pulses from the output of the second magnetic sensor 92. 942, and an up/down counter that counts up or down in accordance with the rotational direction of the rotating shaft based on this clock pulse, and reads the output of the second magnetic sensor as the least significant bit data when a reset signal is input. 943, and a count error detection section 944 that calculates the exclusive OR of the least significant digit of the up/down counter and the output of the second magnetic sensor.

Therefore, the phase of the least significant digit of the output of the up-down counter 943 matches the phase of the second magnetic sensor 92, and if the exclusive OR of both signals becomes the logic signal "1", the up-down counter 943 Indicates that a counting error has occurred.

Furthermore, the data processing unit 306 of the rotary encoder conversion unit 30 includes a code conversion unit 3061 that converts the rotation angle data into a binary code, a negative value of the most significant digit a of the output of the code conversion unit 3061, and the least significant digit of the rotation number data. Consisting of a logical product calculating section 3062 that calculates the logical product of 2 and 3, and a synchronous adding section 3063 that synchronously adds the output of the logical product calculating section 3062 to one or more digits above the least significant digit of the output of the up/down counter 942. be done.

Therefore, at the timing when the most significant digit of the rotary encoder falls, that is, every time the rotating shaft rotates once, the rotation number data also rises or falls.

In this example, a magnetic ring and a magnetic sensor are used as the disk and sensor for detecting the number of rotations.
The present invention is not limited to this, and other formats, such as optical ones, can be used.

Furthermore, while the equipment to which the rotary encoder is attached is stopped, the rotary encoder does not operate, so it is common practice to turn off the power to reduce power consumption. It is desirable to be able to detect even when the rotation axis is rotated, so by changing the bias in the magnetic sensor amplifier, there are two modes: a normal mode that operates with high frequency characteristics, and a saving mode that operates with low frequency characteristics but low power consumption. You may use an available format by switching the power mode.

Furthermore, the rotary encoder is not limited to the hybrid encoder described in this embodiment, but it is also possible to use an absolute encoder.

[Effects of the Invention] According to the present invention, the detection accuracy of the multi-rotation detection section is as low as 1 of the rotation axis.
Even if the accuracy is such that rotations can be identified, it is possible to maintain the same accuracy as when detecting one rotation with a rotary encoder.

Furthermore, even if a counting error occurs in the rotation number counter, this can be detected quickly.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of the multi-rotation detection rotary encoder according to the present invention, Fig. 2 is a diagram showing a side cross section of the multi-rotation detection port-tally encoder according to the present invention, and Fig. 3 is an enlarged view of the Y section. 4 is a diagram showing the pattern of the rotation angle detection disk. FIG. 5 is a diagram showing the signal processing function. FIG. 6 is a diagram explaining the timing synchronization and count error detection function according to the present invention. FIG. 7 is a timing diagram illustrating timing synchronization according to the present invention. In the figure, 100... Disc for detecting number of rotations, 101... First detection means, 102... Second detection means, 103... Number of rotations counting means, 104... Rotary encoder, 105. ... logical product operation means, 106 ... synchronous addition means, 107 ... initial value setting means, 108 ... count error detection means. Increment signal pattern 4] Rotation angle detection disc pattern Fig. 4 Multi-rotation detection rotary encoder Fig. 2 Enlarged view of Y section Fig. 3

Claims (1)

[Claims] 1. A rotation number detection disk (100) on which a different pattern is formed for each half rotation of a rotating shaft, and the disk (100).
0) First detection means (101) for detecting the above pattern
and a second detection means (102) that obtains an output that is 90° out of phase with the output of the first detection means (101); A multi-rotation detection rotary encoder comprising: a rotation number counting means (103) that counts the number of rotations of the disk (100) based on the number of rotations of the disk (100); and a rotary encoder (104) that shares a rotation axis with the disk (100). The least significant digit (LSB) of the number counting means (103)
cnt) and the rotary encoder (1
04) and a logical product of the most significant digit (MSBenc) of the output of
), and the output of the AND operation means (105) and the digit one or more higher than the least significant digit (LSBcnt) of the rotation number counting means (103) are synchronously added to calculate the number of rotations. Synchronous addition means (106) synchronizes the rising and falling timing of the output of the counting means (103) with the falling timing of the output of the rotary encoder (104); and a reset signal is provided to the rotation number counting means (103). The number of rotations counting means (103) is configured such that the phase of the output of the second detection means (102) matches the phase of the output of the least significant digit of the number of rotations counting means (103) when the voltage is applied. Initial value setting means (1
07) A rotary encoder characterized by being provided with. 2. Counting error that detects that a counting error has occurred in the counter when the output of the second detection means (102) and the logic signal value of the least significant digit of the rotation number counting means (103) do not match. The multi-rotation detection rotary encoder according to claim 1, further comprising detection means (108).