An inductive absolute encoder

Abstract

The present invention discloses an inductive absolute encoder, including a code disk and a code reading circuit. N code channels are evenly arranged on the code disk, and each code channel is provided with a code disk circuit; a second inductor is provided near the edge of the code disk on the code reading circuit, and a first inductor is provided near the edge of the code disk on the code disk circuit. In the present invention, each code channel is preset, that is, the code channel value of each encoder reading the code channel is fixed, and there is no need to power off and memorize, and there is no need to find a reference point, there is no error code, and the data reliability is high. The inductive encoder is less affected by the environment and has strong anti-interference characteristics, thereby improving the accuracy. Wireless charging is performed only when the code channel value is read, so that the code disk circuit works to read the code channel value, and no power supply is required at ordinary times, thereby reducing power consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of encoders, and in particular to an inductive absolute encoder. Background Art

[0002] With the development of technology, encoders are used more and more widely. According to the detection principle, they include photoelectric encoders and magnetoelectric encoders.

[0003] In natural light environments, the light source of photoelectric encoders is easily affected by ambient light, such as sunlight, which makes detection susceptible to interference, affecting reliability and accuracy, and may cause bit errors; in dusty and dirty environments such as industrial applications, pollutants will accumulate on the code disk, thereby hindering the transmission of light to the optical sensor, which may cause discontinuous or complete loss of the waveform, greatly affecting reliability and accuracy; the light source LED has a limited service life and will eventually burn out, causing encoder failure; glass or plastic code disks are easily damaged by vibration or extreme temperatures, thus limiting the scope of application of optical encoders in harsh environment applications; assembly is time-consuming and there is a greater risk of contamination, and assembly tolerances are prone to bit errors; if the optical encoder has a higher resolution, it will consume more than 100mA of current, further affecting its application in mobile devices or battery-powered devices; it is not resistant to environmental corrosion.

[0004] The electromagnetic interference generated by the motor of the magnetoelectric encoder (especially the stepper motor) will have a great impact on the magnetic encoder; temperature changes will also cause it to drift in position; the resolution and accuracy of the magnetic encoder are relatively low. Summary of the invention

[0005] In view of the problem of low encoder accuracy in the prior art, the present invention proposes an inductive absolute encoder, which reduces the impact of the environment by presetting code channels and code disk circuits on the code disk and transmits signals through inductance, has strong anti-interference characteristics, and thus improves accuracy.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] An inductive absolute encoder comprises a code disk and a code reading circuit. The code disk is evenly provided with N code channels, and each code channel is provided with a code disk circuit. A second inductor is provided on the code reading circuit near the outer edge of the code disk, and a first inductor is provided on the code disk circuit near the outer edge of the code disk.

[0008] The advantage of this is that each code channel is preset, that is, the code channel value read by each encoder is fixed, no power-off memory is required, no reference point is required, no code errors are caused, and data reliability is high. When reading the code channel value, the first inductor and the second inductor wirelessly induct and then wirelessly charge the code disk circuit, so that the code disk circuit works to read the code channel value, and no power supply is required at ordinary times, thereby reducing power consumption.

[0009] Preferably, the code disk is rotatably installed, and the code reading circuit is fixedly installed.

[0010] Preferably, the code disc is a printed circuit board.

[0011] The advantage of this is that the code disk can resist electromagnetic interference from the environment.

[0012] Preferably, the code disk, code reading circuit and code disk circuit are all installed in a sealed manner.

[0013] The advantage of this is anti-corrosion and waterproof.

[0014] Preferably, the first inductor and the second inductor include a printed circuit board inductor, a coreless wire-wound inductor, and a core-wound inductor.

[0015] Preferably, the code disk circuit comprises:

[0016] The power bus is respectively connected to the power supply end of the logic controller, the power supply end of the encoder, one end of the first capacitor and the cathode of the first diode. The signal output end of the logic controller is connected to the signal input end of the encoder. The signal output end of the encoder is respectively connected to the anode of the first diode and one end of the first inductor. The other end of the first inductor and the other end of the first capacitor are connected in parallel and then grounded.

[0017] Preferably, the code reading circuit comprises:

[0018] The power supply end of the carrier generator is connected to VCC, the signal output end of the carrier generator is respectively connected to one end of the second inductor and one end of the pre-processing module, the other end of the pre-processing module is connected to one end of the decoder, and the other end of the decoder outputs the code channel value; the other end of the second inductor is grounded.

[0019] Preferably, the power of the code disk circuit is provided by the code reading circuit through wireless charging.

[0020] Preferably, the second inductance width is M times the first inductance width, where M≥1. The advantage of such a setting is that the rotation direction of the code disk can be determined.

[0021] In summary, due to the adoption of the above technical solution, compared with the prior art, the present invention has at least the following beneficial effects:

[0022] In the present invention, each code channel is preset, that is, the code channel value read by each encoder is fixed, no power-off memory is required, no reference point is required, no code error occurs, and data reliability is high. The inductive encoder is less affected by the environment and has strong anti-interference characteristics, thereby improving accuracy. Wireless charging is performed only when the code channel value is read, so that the code disk circuit works to read the code channel value, and no power supply is required at other times, thereby reducing power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of an inductive absolute encoder according to an exemplary embodiment of the present invention.

[0024] Figure 2 Schematic diagram of a code disk circuit according to an exemplary embodiment of the present invention.

[0025] Figure 3 FIG. 4 is a schematic diagram of a code reading circuit according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the examples and specific implementation methods. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0027] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] like Figure 1 As shown, the present invention provides an inductive absolute encoder, including a code disk 1 and a code reading circuit 2. N (N ≥ 2 and an integer, preferably 20) code channels are uniformly preset on the code disk 1, and each code channel is provided with a code disk circuit 3. A code reading inductor (second inductor) L2 is provided on the code reading circuit 2 near the edge of the code disk 1, and a code channel inductor (first inductor) L1 is provided on the code disk circuit 3 near the edge of the code disk 1, that is, L1 and L2 are installed close to each other to facilitate signal transmission and reception.

[0029] In this embodiment, the code disc 1 can be a printed circuit board, which is centrally mounted for rotation, and the code reading circuit 2 is fixedly mounted, so that when the code disc 1 rotates, the code reading circuit 2 can read different code channel values.

[0030] In this embodiment, the code disk 1, the code reading circuit 2 and the code disk circuit 3 can all be sealed with a potting material to prevent corrosion and waterproofing, and can be used in harsh environments.

[0031] In this embodiment, in order to prevent electromagnetic interference, electromagnetic shielding materials such as copper strips, steel strips, and silver plating may be installed on both sides of the code disk 1 .

[0032] In this embodiment, the first inductor L1 and the second inductor L2 include a printed circuit board inductor, a coreless wire-wound inductor, and a core-wound inductor.

[0033] In this embodiment, Figure 2 As shown, the specific circuit of the code disk circuit 3 is:

[0034] The power bus (VDD) is respectively connected to the power end of the logic controller, the power end of the encoder, one end of the first capacitor C1 and the cathode of the first diode D1; the signal output end of the logic controller is connected to the signal input end (In) of the encoder; the signal output end (out) of the encoder is respectively connected to the anode of the first diode D1 and one end of the first inductor L1; the other end of the first inductor L1 and the other end of the first capacitor C1 are connected in parallel and then grounded.

[0035] In this embodiment, the power supply ends of N code disk circuits 3 are connected to a bus, and the capacitors in the N code disk circuits 3 are stored at the same time. Multiple capacitors connected in parallel can form a larger energy storage capacitor. When the energy storage of all capacitors meets the energy required by the corresponding encoder, the encoder starts to work. In this way, when one code disk circuit 3 is charged, all code disk circuits 3 can be charged at the same time, ensuring the power of other code disk circuits 3, thereby ensuring work efficiency.

[0036] In this embodiment, Figure 3 As shown, the code reading circuit 2 includes a carrier generator, a pre-processing module and a decoder:

[0037] The power supply end of the carrier generator is connected to VCC (external power supply P), the signal output end of the carrier generator is respectively connected to one end of the second inductor L2 and one end (signal input end) of the pre-processing module, the other end (signal output end) of the pre-processing module is connected to one end (signal input end) of the decoder, and the other end (signal output end) of the decoder outputs the code channel value; the other end of the second inductor L2 is grounded.

[0038] In this embodiment, the electric energy of the code disk circuit 3 is provided by the code reading circuit 2 through a wireless charging method. The wireless charging method is: the carrier generator in the code reading circuit 2 generates a high-frequency signal to drive the second inductor L2, thereby forming a magnetic field near the second inductor L2; when the first inductor L1 in the code disk circuit 3 rotates close to the second inductor L2, the first inductor L1 converts the magnetic field into an electric field, and its induced voltage passes through the first diode D1 and is stored in the first capacitor C1 to form the electric energy required by the encoder.

[0039] The working principle of the present invention is:

[0040] The encoder in the code disk circuit 3 converts the corresponding code channel value (different code channels have different code channel values) into a bit stream according to a predetermined coding rule (such as Manchester coding, binary coding, etc.). The bit stream acts on the first inductor L1, and the electric field strength of the first inductor L1 changes with the bit stream. According to the electromagnetic field interaction theory, the magnetic field of the second inductor L2 changes accordingly, and the bit stream signal and the carrier signal (FM or AM) of the carrier generator are superimposed to obtain the end signal of the second inductor L2; the end signal of the second inductor L2 is processed by the pre-processing module (such as rectification, filtering, amplification, etc.) to restore the bit stream information corresponding to the code channel, and the bit stream information can be read by the decoder to obtain the corresponding code channel value.

[0041] In this embodiment, the width of the second inductor L2 is M times (M≥1, preferably 1-3) of the first inductor L1. When the second inductor L2 moves to the interval position between two code tracks, two first inductors L1 simultaneously sense the magnetic field generated by the second inductor L2, and two code track values ​​can be read. The rotation direction of the code disk 1 can be determined through the arrangement relationship and algorithm. For example, the code tracks are arranged clockwise in the order of a, b, and c. If the code reading circuit reads the code track values ​​of a, b, and c in sequence, it means that the code disk 1 rotates clockwise; if the code reading circuit reads the code track values ​​of c, b, and a in sequence, it means that the code disk 1 rotates counterclockwise.

[0042] Because each code channel is preset, that is, the code channel value read by each encoder is fixed, there is no need to power off and memorize, no need to find a reference point, anti-interference characteristics, high data reliability, no error code. And the code disk circuit 3 works to read the code channel value only when the code channel value is read, and no power supply is required at other times, thereby reducing power consumption.

[0043] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. An inductive absolute encoder, characterized in that: The invention comprises a code disk (1) and a code reading circuit (2), wherein N code tracks are arranged on the code disk (1), and a code disk circuit (3) is arranged on each code track; a second inductor (L2) is arranged on the code reading circuit (2) near the outer edge of the code disk (1), and a first inductor (L1) is arranged on the code disk circuit (3) near the outer edge of the code disk (1); The code disk circuit (3) forms a bit stream with the code channel value of the corresponding code channel. When the bit stream acts on the first inductor (L1), the electric field strength of the first inductor (L1) changes with the bit stream, and the magnetic field of the second inductor (L2) changes accordingly. The bit stream signal and the carrier signal are superimposed to obtain the end signal of the second inductor (L2). The code reading circuit (2) processes the end signal to restore the bit stream information corresponding to the code channel. The bit stream information can be read by the decoder to obtain the corresponding code channel value.

2. An inductive absolute encoder as claimed in claim 1, characterized in that: The code disc (1) is rotatably mounted, and the code reading circuit (2) is fixedly mounted.

3. An inductive absolute encoder as claimed in claim 1, characterized in that: The code disc (1) is a printed circuit board.

4. An inductive absolute encoder as claimed in claim 1, characterized in that: The code disk (1), code reading circuit (2) and code disk circuit (3) are all installed in a sealed manner.

5. An inductive absolute encoder as claimed in claim 1, characterized in that: The first inductor (L1) and the second inductor (L2) include printed inductors, coreless wire-wound inductors and coreless wire-wound inductors.

6. An inductive absolute encoder as claimed in claim 1, characterized in that: The code disk circuit (3) comprises: The power bus is respectively connected to the power supply end of the logic controller, the power supply end of the encoder, one end of the first capacitor and the cathode of the first diode. The signal output end of the logic controller is connected to the signal input end of the encoder. The signal output end of the encoder is respectively connected to the anode of the first diode and one end of the first inductor. The other end of the first inductor and the other end of the first capacitor are connected in parallel and then grounded.

7. An inductive absolute encoder as claimed in claim 1, characterized in that: The code reading circuit (2) comprises: The power supply end of the carrier generator is connected to VCC, the signal output end of the carrier generator is respectively connected to one end of the second inductor and one end of the pre-processing module, the other end of the pre-processing module is connected to one end of the decoder, and the other end of the decoder outputs the code channel value; the other end of the second inductor is grounded.

8. An inductive absolute encoder as claimed in claim 1, characterized in that: The electric energy of the code disk circuit (3) is provided by the code reading circuit (2) through wireless charging.

9. An inductive absolute encoder as claimed in claim 1, characterized in that: The width of the second inductor (L2) is M times the width of the first inductor (L1), where M≥1.

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