TWM495504U - Absolute encoder - Google Patents

Description

Absolute encoder

This paper is about an absolute encoder, especially an absolute encoder for the angular position of a single axis of the energy measuring shaft and the number of revolutions of the measuring shaft.

An encoder is a sensor used to detect angle, position, velocity, and acceleration. When used in a motor device, input information such as a rotational position or a rotational amount can be converted into an analog or digital signal by a logic circuit having an encoding function. Common encoder types are, for example, mechanical, optical and magnetic induction. Encoders can also be functionally divided into incremental and absolute.

In general, an incremental encoder can only be used to provide a message with the current position relative to the previous position, that is, it can only be used to obtain a relative position signal. On the other hand, the incremental encoder does not have the function of remembering the current absolute position. Therefore, the incremental encoder is applied to the motor equipment. When the motor equipment is de-energized, if the mechanical position changes due to the external force moving or rotating, the position is shifted, and when the motor equipment is restarted, the incremental coding is performed. The device cannot obtain the current absolute position signal, and it is impossible to judge whether the signal at the current position is the same as the signal recorded before the stop, so the encoder must be adjusted to perform the process of returning to the origin.

Unlike incremental encoders, absolute encoders provide absolute position measurement in addition to the functions of incremental encoders. In other words, the absolute value of the rotation angle or position of the shaft of the motor device can be output immediately. Absolute encoder when the motor equipment is powered off and then re-powered The absolute value signal of the current rotation angle or position of the shaft can be read instantly.

Absolute encoders widely used in industrial production are mostly photoelectric. However, the grating disk of the photoelectric encoder has low impact resistance and vibration resistance. Therefore, when the grating disk of the photoelectric encoder is rotated about the axis, it is easy to break the grating disk due to the vibration of the shaft. On the other hand, photoelectric encoders have poor environmental adaptability and are less resistant to moisture, dust and temperature changes.

In view of this, today's electromechanical equipment has gradually developed into a magnetic induction type absolute encoder, which has a simple structure, a fast response speed and strong anti-interference ability to the environment. A variety of magnetic inductive encoder chips are currently on the market, one of which is a non-contact magnetic rotary encoder that integrates Hall elements, analog front end and digital signal processing functions in a single component for accurate measurement of motor equipment. The angle of rotation in a 360° range. In use, it is only necessary to set a simple bipolar magnet corresponding to the rotation of the central position of the wafer at the relative position of the wafer. Usually, the magnet is disposed on the rotating shaft of the motor device, and the shaft of the motor device rotates and is converted by the change of the magnetic pole. Signal for a specific location.

However, after the above absolute encoder chip is rotated more than one turn, the code returns to the origin. When the motor equipment is in normal operation, it is often necessary to use an additional logic circuit to assist in recording the current number of revolutions. If the motor equipment is powered off and the recorded number of revolutions is lost, after the motor equipment is restarted, even if the absolute encoder can read the current absolute position signal, it is impossible to know the current rotation position. The rotation of the circle, so it must take time to carry out the origin return process of the shaft.

The purpose of this creation is to provide an absolute encoder that records and calculates the number of revolutions of the shaft when the motor is powered off, and after the motor equipment is restarted, the measurement is turned The angle of rotation of the shaft in a single turn and the current number of revolutions of the shaft.

For the above purposes, the present invention provides an absolute encoder comprising: a central magnet and an outer ring magnet, the central magnet and the outer ring magnet being concentrically disposed on a rotating shaft; a magnetic inductive encoder corresponding to The central position of the central magnet is spaced apart to measure the rotation angle of the rotating shaft in a single turn; a magnetic induction component is used to sense the magnetic pole change when the outer ring magnet rotates to output a high level signal and a low a square wave signal of the level signal; and a controller electrically connected to the magnetic induction component for receiving the square wave signal and converting into a rotating circle signal according to the received square wave signal.

In a preferred embodiment of the present invention, when the magnetic induction component senses the north pole of the outer ring magnet, the high level signal is output, and when the magnetic induction component senses the south pole of the outer ring magnet, the low level is output. Signal. The magnetic induction component includes a first Hall element and a second Hall element, and the first Hall element senses a magnetic pole change when the outer ring magnet rotates, outputs a first square wave signal, and the second Hall element The magnetic pole change when the outer ring magnet rotates is sensed, and the second square wave signal is output.

In another preferred embodiment of the present invention, the absolute encoder further includes a battery, and the controller includes a memory unit for recording the rotation number signal. The battery provides a current to the magnetic sensing component and the memory unit when the spindle stops rotating. In addition, the controller includes a clear function for receiving a clearing loop signal and zeroing the recorded number of revolutions.

In another preferred embodiment of the present invention, when the rotating shaft is forward rotation, the controller receives the rising edge of the first square wave signal from the first Hall element, and the second Hall element outputs the low edge. a level signal, or the controller receives the first Hall element to output the first square wave The falling edge of the number, and the second Hall element outputs the high level signal. When the rotating shaft is reversed, the controller receives the rising edge of the first square wave signal from the first Hall element, and the second Hall element outputs the high level signal, or the controller receives the first A Hall element outputs a falling edge of the first square wave signal, and the second Hall element outputs the low level signal.

In another preferred embodiment of the present invention, when the controller receives the rising edge of the second square wave signal from the second Hall element, and the first Hall element outputs the high level signal, The controller increases the count of the number of revolutions by one; when the controller receives the rising edge of the first square wave signal from the first Hall element, and the output of the second Hall element is the high level When the signal is received, the controller decrements the count of the number of revolutions by one.

100‧‧‧Absolute encoder

110‧‧‧Magnetic sensing components

112‧‧‧First Hall element

114‧‧‧Second Hall element

120‧‧‧ Controller

130‧‧‧Magnetic Inductive Encoder

140‧‧‧Central Magnet

145‧‧‧Outer ring magnet

150‧‧‧ shaft

160‧‧‧ boards

170‧‧‧Rotation angle in a single circle

122‧‧‧ memory unit

161‧‧‧Voltage conversion unit

162‧‧‧Charging circuit

163, 165‧‧‧ voltage detection unit

164‧‧‧Power switch

270‧‧‧External circuit

280‧‧‧External power supply

282‧‧‧Battery

284‧‧‧ Capacitance

D‧‧‧Clear lap signal

Rx‧‧‧ rotating circle number signal

H1‧‧‧First Square Wave Signal

H2‧‧‧Second Square Wave Signal

H‧‧‧High level signal

L‧‧‧ low level signal

A, B, Z‧‧‧ signals

Figure 1A shows the absolute encoder of the present creation.

Figure 1B shows a partial view of the absolute encoder of the present invention.

Figure 2 is a block diagram showing the circuit of the absolute encoder of the present invention.

FIG. 3A is a diagram showing the square wave signal outputted by the magnetic induction component of the present invention when the outer ring magnet is rotating forward.

FIG. 3B is a diagram showing the square wave signal outputted by the magnetic induction component of the present invention when the outer ring magnet is reversed.

The preferred embodiment of the present invention is described in detail with reference to the accompanying drawings

Please refer to FIG. 1A and FIG. 1B. FIG. 1A shows the absolute encoder of the present invention, and FIG. 1B shows a partial view of the absolute encoder of the present invention. Absolute encoder 100 includes a central magnet 140 and an outer ring magnet 145, a magnetic induction assembly 110, a controller 120, a magnetic induction encoder 130, and a circuit board 160 that are concentrically disposed on the rotating shaft 150. The magnetic inductive encoder 130 is positioned on a central axis of rotation of the central magnet 140 and the outer ring magnet 145, and is disposed at a position spaced apart from the central magnet 140 by a central axis position corresponding to the rotation of the central magnet 140.

The magnetic induction component 110 is adjacent to the magnetic induction encoder 130 and is spaced apart from the outer ring magnet 145. The magnetic induction component 110 is configured to sense a magnetic pole change when the outer ring magnet 145 rotates, and output a corresponding square wave signal. More specifically, as shown in FIG. 1B, the outer ring magnet 145 is a bipolar magnet. For example, when the outer shape of the ring magnet 145 is annular, the half of the outer ring magnet 145 is an arc. (N pole), the other half of the ring is the South Pole (S pole). Therefore, when the outer ring magnet 145 rotates with the rotating shaft 150, the magnetic induction component 110 outputs a high level signal when sensing the N pole of the outer ring magnet 145, and conversely, when the magnetic sensing component 110 senses the S pole of the outer ring magnet 145. , output low level signal.

The present invention can avoid the central magnet 140 and the magnetic induction encoder 130 and the magnetic induction assembly 110 by respectively providing two different magnets (the central magnet 140 and the outer ring magnet 145) on the rotating shaft 150. When the magnetic induction components 110 are too far apart from each other, the magnetic induction component 110 cannot accurately output the corresponding high-level signal or low-level signal due to external signal interference.

According to a preferred embodiment of the present invention, the magnetic sensing component 110 can further include a first Hall element 112 and a second Hall element 114. The first Hall element 112 and the second Hall element 114 are disposed adjacent to the magnetic inductive encoder 130, respectively, and the connection of the first Hall element 112 to the magnetic inductive encoder 130 and the second Hall element 114 and magnetic induction The lines of the encoder 130 form an angle. According to a preferred embodiment of the present invention, the angle of the angle is between 80 and 90 degrees. between.

The controller 120 is electrically connected to the magnetic induction component 110. The controller 120 receives the square wave signal output by the magnetic induction component 110, and converts the received square wave signal into a rotating circle number signal. More specifically, the magnetic induction component 110 senses that the magnetic pole alternates between the N pole and the S pole when the outer ring magnet 145 rotates, and then includes a high level signal and a low level according to the output corresponding to the sensed N pole and the S pole. The square wave signal of the number. The controller 120 receives the square wave signal output by the magnetic induction component 110, determines whether the current outer ring magnet 145 is forward or reverse, and the number of rotations, and records and records the obtained rotation ring number signal inside the controller 120. In addition, according to another preferred embodiment of the present invention, the controller 120 further includes a memory unit for recording the number of revolutions.

The magnetic inductive encoder 130 is located on the central axis of rotation of the central magnet 140 and is spaced from the central magnet 140 at a central axis position corresponding to the rotation of the central magnet 140. The magnetic inductive encoder 130 is a non-contact magnetic rotary encoder that integrates a Hall element, an analog front end, and a digital signal processing function in a single component. In use, the magnetic inductive encoder 130 converts the change of the magnetic pole generated by the central magnet 140 when the rotating shaft 150 is rotated into a specific position signal, thereby accurately measuring the rotation angle 170 of the rotating shaft 150 in a single turn.

According to a preferred embodiment of the present invention, the magnetic sensing component 110, the controller 120, and the magnetic inductive encoder 130 can be disposed on the same circuit board 160.

Please refer to FIG. 2, which is a block diagram showing the circuit of the absolute encoder of the present invention. When the absolute encoder of the present invention is applied to a motor device, the external power source 280 of the motor device external circuit 270 provides power to the circuit board 160 of the absolute encoder under normal operation of the motor device. After the voltage provided by the external power source 280 enters the circuit board 160, the power is passed. The voltage conversion unit 161 is converted to an operating voltage. The external power source 280 is primarily used to provide the power required to operate the first Hall element 112, the second Hall element 114, the controller 120, and the magnetic inductive encoder 130 within the circuit board 160. The magnetic induction encoder 130 converts the specific magnetic signals, such as the position and angle A, B and Z signals, according to the change of the magnetic pole generated when the central magnet 140 rotates, so that the rotation axis of the motor device can be accurately measured in a single circle. Rotation angle. The controller 120 receives the first Hall element 112 and the second Hall element 114 to induce a change in the magnetic pole of the outer ring magnet when the rotating shaft of the motor device rotates, and outputs a corresponding square wave signal, thereby outputting a corresponding rotation number signal Rx. .

In addition, after the external power source 280 is converted to the operating voltage, it will pass through the charging circuit 162 to charge the capacitor 284. Thus, when the electrical equipment is powered down, even if the external power supply 280 no longer provides power to the circuit board 160 of the absolute encoder, the circuit board 160 can provide the required power by the capacitor 284. According to a preferred embodiment of the present invention, an external battery 282 is further electrically coupled to the circuit board 160. Therefore, when the external power source 280 stops supplying power, the battery 282 can continue to provide power to the circuit board 160. In addition, the circuit board 160 internally includes voltage detecting units 163 and 165 and a power conversion switch 164. The voltage detecting unit 163 is configured to detect the current voltage of the external power source 280 and the capacitor 284, and the power switch 164 is switched to the first Hall element 112 and the second Hall element according to the signal transmitted by the voltage detecting unit 163. 114 and a source of power for controller 120, the source of which is one of external power source 280, battery 282, or capacitor 284.

It can be understood that, according to FIG. 2, when the motor device is operating normally, the external power source 280 provides power to the magnetic inductive encoder 130, the first Hall element 112, the second Hall element 114, and the controller 120. When the external power source 280 stops supplying power, the first Hall element 112, the second Hall element 114, and the controller 120 can be continuously powered by the capacitor 284 or the battery 282. More specifically, capacitor 284 or battery 282 is not used to provide power to magnetic inductive encoder 130. According to a preferred embodiment of the present invention, when the external power source 280 is powered off and the motor device is not rotating, the capacitor 284 or battery 282 will only provide power to the first Hall element 112, the second Hall element 114, and the controller 120. Memory unit 122. It should be noted that the first Hall element 112, the second Hall element 114, and the memory unit 122 of the controller 120 consume less than 50μA, so that the absolute encoder of the present invention can remain in relative when no external power supply is provided. Low power consumption and power saving. That is to say, the data of the rotation number signal Rx stored by the internal memory unit 122 of the controller 120 is not lost due to the long-term power failure of the motor equipment.

According to a preferred embodiment of the present invention, the controller 120 further includes a clear function for receiving the clear circle number signal D and zeroing the recorded number of revolutions.

Please refer to Figures 3A and 3B. FIG. 3A is a diagram showing the square wave signal outputted by the magnetic induction component of the present invention when the outer ring magnet is rotating forward. FIG. 3B is a diagram showing the square wave signal outputted by the magnetic induction component of the present invention when the outer ring magnet is reversed. According to a preferred embodiment of the present invention, the magnetic induction assembly of the present invention further includes a first Hall element and a second Hall element. In FIGS. 3A and 3B, the first square wave signal H1 output by the first Hall element and the second square wave signal H2 output by the second Hall element have a phase difference of 90 degrees. When the outer ring magnet rotates forward, the phase of the first square wave signal H1 output by the first Hall element is in front; and when the outer ring magnet is reversed, the phase of the second square wave signal H2 output by the second Hall element in front.

As shown in FIG. 3A, when the rotating shaft is forward rotation, the controller receives the rising edge of the first square element outputting the first square wave signal H1, and the current output of the second Hall element is the low level signal L, Or the controller receives the falling edge of the first square element outputting the first square wave signal H1, and the current output of the second Hall element is the high level signal H. On the contrary, referring to Figure 3B, When the rotating shaft is reversed, the controller receives the rising edge of the first square element output first square wave signal H1, and the current output of the second Hall element is the high level signal H, or the controller receives the first The Hall element outputs a falling edge of the first square wave signal H1, and the second Hall element currently outputs a low level signal L.

Referring to FIGS. 3A and 3B, the first square wave signal H1 output by the first Hall element and the second square wave signal H2 output by the second Hall element are divided into the 0th to the 3rd. The area is used to indicate that the magnet is divided into four regions by one rotation, and the zeroth region represents the origin. That is to say, when the controller receives the signal triggering the 0th zone, it will increase or decrease the number of revolutions. When the controller receives the rising edge of the second square element outputting the second square wave signal, and the first Hall element outputs a low level signal, it indicates that the magnet is currently in the forward direction and passes through the 0th zone, therefore, the controller The count of the number of revolutions is increased by one. Similarly, when the controller receives the rising edge of the first square wave signal output by the first Hall element, and the second Hall element outputs a high level signal, it indicates that the magnet is currently reversed and passes through the 0th zone, therefore, The controller will decrement the count of the number of revolutions by one.

Although the present invention has been disclosed in its preferred embodiments, it is not intended to limit the present invention, and anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. The scope of protection is subject to the definition of the scope of the patent application.

100‧‧‧Absolute encoder

110‧‧‧Magnetic sensing components

112‧‧‧First Hall element

114‧‧‧Second Hall element

120‧‧‧ Controller

130‧‧‧Magnetic Inductive Encoder

140‧‧‧Central Magnet

145‧‧‧Outer ring magnet

150‧‧‧ shaft

160‧‧‧ boards

Claims (11)

An absolute encoder comprising: a central magnet and an outer ring magnet, the central magnet and the outer ring magnet being concentrically disposed on a rotating shaft; and a magnetic inductive encoder corresponding to a central position of the central magnet rotating The magnetic induction component is configured to sense a magnetic pole change when the outer ring magnet rotates to output a square wave signal including a high level signal and a low level signal; And a controller electrically connected to the magnetic induction component for receiving the square wave signal and converting the square wave signal into a rotating circle signal. The absolute encoder according to claim 1, wherein when the magnetic induction component senses the north pole of the outer ring magnet, the high level signal is output, and when the magnetic induction component senses the south pole of the outer ring magnet When the low level signal is output. The absolute encoder of claim 1, wherein the magnetic induction component comprises a first Hall component and a second Hall component, the first Hall component and the second Hall component respectively a magnetic inductive encoder is disposed adjacent to each other, and a line connecting the first Hall element and the magnetic inductive encoder and an intersection of the second Hall element and the magnetic inductive encoder form an angle; the first Hall The component senses a magnetic pole change when the outer ring magnet rotates, outputs a first square wave signal, and the second Hall element senses a magnetic pole change when the outer ring magnet rotates, and outputs a second square wave signal. The absolute encoder of claim 3, wherein the angle of the angle is between 80 degrees and 90 degrees. The absolute encoder according to claim 3, wherein the first square wave signal output by the first Hall element and the second square wave signal output by the second Hall element have a phase difference of 90 degrees. . The absolute encoder according to claim 3, wherein when the rotating shaft is forward rotation, the controller receives the rising edge of the first square wave signal output by the first Hall element, and the second The component outputs the low level signal, or the controller receives the falling edge of the first square wave signal from the first Hall element, and the second Hall element outputs the high level signal. The absolute encoder according to claim 3, wherein when the rotating shaft is reversed, the controller receives the rising edge of the first square wave signal output by the first Hall element, and the second Hall The component outputs the high level signal, or the controller receives the falling edge of the first square wave signal output by the first Hall element, and the second Hall element outputs the low level signal. The absolute encoder of claim 3, wherein the controller receives the rising edge of the second square wave signal by the second Hall element, and the first Hall element outputs the high level When the bit signal is received, the controller increments the count of the number of revolutions. The absolute encoder of claim 3, wherein the controller receives the rising edge of the first square wave signal from the first Hall element, and the second Hall element outputs the high level When the bit signal is received, the controller decrements the count of the number of revolutions by one. The absolute encoder according to claim 1, further comprising a battery, wherein the controller comprises a memory unit for recording the rotation number signal, and the battery provides a current when the rotation shaft stops rotating To the magnetic induction component and the memory unit. The absolute encoder of claim 1, wherein the controller includes a clearing function for receiving a clearing loop signal and zeroing the recorded number of revolutions.