Universal circuit for ABZ differential encoder and ABZ encoder of low-speed vehicle

Abstract

The utility model discloses a low-speed vehicle ABZ differential and ABZ encoder general circuit, which comprises a chip U1, a chip U2, resistors R1, R2, R4, R6, R8, R9, R11, R12, R13, R14, R16, R18 and capacitors C4, C5 and C8, one ends of the resistors R2, R4, R6 and R9 are respectively connected with pins 1, 2, 3 and 4 of the chip U1, one ends of the resistors R13 and R16 are connected with pins 1 and 4 of the chip U2, one end of the R1 is connected between the R2 and a motor, one end of the R8 is connected between the R9 and the motor, one end of the R14 is connected between the R13 and the motor, and the other end of the R14 is connected between the R13 and the motor. And one end of the resistor R11 and one end of the resistor R12 are respectively connected to a pin 7 and a pin 6 of the chip U1. The circuit can be compatible with an ABZ differential encoder and an ABZ encoder at the same time; and the method has the advantages of cost saving, PCB space saving, convenience and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of encoder processing circuits, in particular to a low-speed vehicle ABZ differential and ABZ encoder universal circuit. Background Art

[0002] Low-speed vehicles use motors with different encoders, and in the closed-loop control system of the motor, high-speed, high-precision sensors and corresponding processing circuits are essential because of the need to obtain the position and speed information of the motor in real time. In order to adapt to motors with different types of encoders, we need to use different circuits to process the encoder output signals, which makes the existing technology incompatible with ABZ encoders and ABZ differential encoders at the same time. If multiple encoders need to be compatible, more PCB space will be required and the cost will increase. Summary of the invention

[0003] The utility model aims to provide a universal circuit for ABZ differential and ABZ encoder of a low-speed vehicle.

[0004] To achieve the above purpose, the utility model provides the following technical solutions: a universal circuit for ABZ differential and ABZ encoder of a low-speed vehicle, comprising chips U1, U2, resistors R1, R2, R4, R6, R8, R9, R11, R12, R13, R14, R16, R18, capacitors C4, C5, C8, one end of the resistors R2, R4, R6, R9 are respectively connected to the 1, 2, 3, 4 pins of the chip U1, the other end of the resistors R2, R4, R6, R9 are connected to the A+, A-, B-, B+ ends of the motor, one end of the R13, R16 is connected to the 1, 4 pins of the chip U2, and the other end of the R13, R16 is connected to the electric The Z+ and Z- ends of the machine, resistors R2, R4, R6, R9, R13, and R16 are used for current limiting to protect chips U1 and U2. One end of R1 is connected between R2 and the motor, one end of R8 is connected between R9 and the motor, one end of R14 is connected between R13 and the motor, one end of resistors R11 and R12 are respectively connected to pins 7 and 6 of chip U1, the other ends of resistors R11 and R12 are respectively connected to C4 and C5, one end of R18 is connected to pin 7 of chip U2, and the other end of R18 is connected to C8; R11, R12, R18, C4, C5, and C8 form a low-pass filter for filtering to reduce interference.

[0005] Furthermore, it also includes resistors R5, R10, and R17 for ensuring the minimum current required for the internal light-emitting diodes of U1 and U2 to conduct. One end of the resistor R5 is connected between R2 and U1, and the other end of the resistor R5 is connected between R4 and U1; one end of the resistor R10 is connected between R6 and U1, and the other end of the resistor R10 is connected between R9 and U1; one end of the resistor R17 is connected between R13 and U2, and the other end of the resistor R17 is connected between R16 and U2.

[0006] Furthermore, it also includes resistors R3, R7, and R15, one end of the resistor R3 is connected between R2 and the motor, and the other end of the resistor R3 is connected between R4 and the motor; one end of the resistor R7 is connected between R6 and the motor, and the other end of the resistor R7 is connected between R9 and the motor; one end of the resistor R15 is connected between R13 and the motor, and the other end of the resistor R15 is connected between R16 and the motor; R3, R7, and R15 are used to improve signal matching, reduce signal reflection, and stabilize the working state of the differential line pair.

[0007] Furthermore, it also includes C1, C2, C3, C6, and C7 for filtering. The capacitor C1 is connected between R5 and U1, the capacitor C2 is connected between R10 and U1, the capacitor C6 is connected between R17 and U2, the capacitor C3 is connected to pin 8 of U1, and C7 is connected to pin 8 of U2.

[0008] Furthermore, the chips U1 and U2 are both dual-channel optocouplers.

[0009] It can be seen from the above technical solution that the utility model has the following beneficial effects:

[0010] The universal circuit of ABZ differential and ABZ encoder for low-speed vehicles is compatible with both ABZ differential and ABZ encoders; and has the advantages of saving cost, PCB space, convenience, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is the overall circuit diagram of the utility model. DETAILED DESCRIPTION

[0012] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0013] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0014] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0015] See also Figure 1 The utility model provides a low-speed vehicle ABZ differential and ABZ encoder universal circuit, including chips U1, U2, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, capacitors C1, C2, C3, C4, C5, C6, C7, C8; U1, U2 are dual-channel photocouplers, composed of high-speed LED and CMOS The detection chip is composed of an integrated photodiode, a high-speed transimpedance amplifier and a voltage comparator with an output drive circuit in each channel; one end of the resistors R2, R4, R6 and R9 are respectively connected to the 1, 2, 3 and 4 pins of the chip U1, and the other end of the resistors R2, R4, R6 and R9 are connected to the A+, A-, B- and B+ ends of the motor; one end of R13 and R16 are connected to the 1 and 4 pins of the chip U2, and the other end of R13 and R16 are connected to the Z+ and Z+ ends of the motor. -end, resistors R2, R4, R6, R9, R13, and R16 are used for current limiting, one end of R1 is connected between R2 and the motor, one end of R8 is connected between R9 and the motor, one end of R14 is connected between R13 and the motor, one end of the resistors R11 and R12 are connected to pins 7 and 6 of chip U1 respectively, the other ends of the resistors R11 and R12 are connected to C4 and C5 respectively, one end of R18 is connected to pin 7 of chip U2, and the other end of R18 is connected to C8.

[0016] One end of the resistor R5 is connected between R2 and U1, and the other end of the resistor R5 is connected between R4 and U1; one end of the resistor R10 is connected between R6 and U1, and the other end of the resistor R10 is connected between R9 and U1; one end of the resistor R17 is connected between R13 and U2, and the other end of the resistor R17 is connected between R16 and U2.

[0017] One end of the resistor R3 is connected between R2 and the motor, and the other end of the resistor R3 is connected between R4 and the motor; one end of the resistor R7 is connected between R6 and the motor, and the other end of the resistor R7 is connected between R9 and the motor; one end of the resistor R15 is connected between R13 and the motor, and the other end of the resistor R15 is connected between R16 and the motor.

[0018] The capacitor C1 is connected between R5 and U1, the capacitor C2 is connected between R10 and U1, the capacitor C6 is connected between R17 and U2, the capacitor C3 is connected to pin 8 of U1, and C7 is connected to pin 8 of U2.

[0019] Among them, R1, R8, and R14 are optional resistors compatible with two encoder circuits; when the encoder used by the motor is an ABZ decoder, resistors R1, R8, and R14 need to be attached to the PCB board; when the encoder used by the motor is an ABZ differential decoder, resistors R1, R8, and R14 need to be hollowed out on the PCB board, and two different encoders can be adapted by simply depending on whether the resistors R1, R8, and R14 are welded; R2, R4, R6, R9, R13, and R16 play the role of current limiting to protect U1 and U2 from damage; R5, R10, and R17 play the role of ensuring the minimum current required for the light-emitting diodes inside U1 and U2 to turn on; R3, R7, and R15 matching resistors can improve signal matching, reduce signal reflection, and stabilize the working state of the differential line pair. This can effectively improve the quality of data transmission and improve the reliability of the system. C1, C2, C3, C6, and C7 play a filtering role; R11, R12, R18, C4, C5, and C8 form a low-pass filter to filter and reduce interference.

[0020] When the motor uses an ABZ encoder, A+, B+, and Z+ are left floating, and A-, B-, and Z- are connected to A, B, and Z of the ABZ decoder; when A- inputs a low level, +5V flows into U1's pin 1 through R2, flows out from U1's pin 2 through R4, and the light-emitting diode inside U1 is turned on, so that U1's pin 7 outputs a low level, which is filtered by the low-pass filter composed of R11 and C4 and given to the EQEPA pin of the DSP; when A- inputs a high level, the light-emitting diode inside U1 is not turned on, so that U1's pin 7 outputs a high level, which is filtered by R11 and C4 and passed to the EQEPA of the DSP; by the same token, when B- inputs a low level, +5V flows into U1's pin 3 through R9, flows out from U1's pin 4 through R6, and the light-emitting diode inside U1 is turned on, so that U1's pin 6 outputs a low level, which is filtered by the low-pass filter composed of R12 and C5 and given to D SP's EQEPB pin; when B- inputs a high level, the light-emitting diode inside U1 is not turned on, so that pin 6 of U1 outputs a high level, which is filtered by R12 and C5 and transmitted to EQEPB of DSP; when Z- inputs a low level, +5V flows into pin 1 of U2 through R13, flows out from pin 2 of U2 through R16, at which time the light-emitting diode inside U2 is turned on, so that pin 7 of U2 outputs a low level, which is filtered by the low-pass filter composed of R18 and C8 and given to the EQEPZ pin of DSP; when Z- inputs a high level, the light-emitting diode inside U1 is not turned on, so that pin 7 of U2 outputs a high level, which is filtered by R18 and C8 and transmitted to EQEPZ of DSP; the EQEP circuit inside DSP can decode and count the orthogonal encoding pulse A, B, and Z signals generated by the encoder fixed on the motor shaft, so as to obtain information such as the position and speed of the motor.

[0021] When the motor uses an ABZ differential encoder, R1, R8, and R14 need to be hollowed out. At this time, A+ and A- input a set of mutually anti-phase (180-degree phase difference) signals. When A+ is high and A- is low, the light-emitting diode inside U1 is turned on, and pin 7 of U1 outputs a low level; conversely, when A+ is low and A- is high, the light-emitting diode inside U1 is not turned on, and pin 7 of U1 outputs a high level; similarly, when B+ is high and B- is high, the light-emitting diode inside U1 is not turned on, and pin 7 of U1 outputs a high level. When B+ is low, the LED inside U1 is turned on, and the 6th pin of U1 outputs a low level; conversely, when B+ is low and B- is high, the LED inside U1 is not turned on, and the 6th pin of U1 outputs a high level; when Z+ is high and Z- is low, the LED inside U2 is turned on, and the 7th pin of U2 outputs a low level; conversely, when Z+ is low and Z- is high, the LED inside U2 is not turned on, and the 7th pin of U2 outputs a high level;

[0022] When EQEPA, EQEPB, and EQEPZ are input to DSP, the general timer T2 is usually selected to perform orthogonal decoding and counting on the input pulses. To make the EQEP circuit work properly, T2 must work in the directional increase / decrease mode. In this mode, the EQEP circuit not only provides counting pulses for timer T2, but also determines its counting direction. The EQEP circuit counts both the rising and falling edges of the input orthogonal encoding pulses. Therefore, the input orthogonal encoding pulses are quadrupled as the counting pulses of T2, and the direction detection logic of the EQEP circuit is used to determine which pulse sequence has a phase lead, and then a direction signal is generated as the direction input of T2. When the motor rotates forward, T2 counts up, and when the motor rotates reversely, T2 counts down. In this way, the rotation direction of the motor can be determined and the position and speed information of the motor can be obtained in real time.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A universal circuit for ABZ differential and ABZ encoder of low-speed vehicles, characterized in that: Including chips U1, U2, resistors R1, R2, R4, R6, R8, R9, R11, R12, R13, R14, R16, R18, capacitors C4, C5, C8, one end of the resistors R2, R4, R6, R9 are connected to the 1, 2, 3, 4 pins of the chip U1 respectively, the other end of the resistors R2, R4, R6, R9 are connected to the A+, A-, B-, B+ ends of the motor, one end of the R13, R16 is connected to the 1, 4 pins of the chip U2, the other end of the R13, R16 is connected to the Z+, Z- ends of the motor, resistors R2, R4, R6, R9 , R13, and R16 are used to limit the current to protect chips U1 and U2. One end of R1 is connected between R2 and the motor, one end of R8 is connected between R9 and the motor, and one end of R14 is connected between R13 and the motor. One end of the resistors R11 and R12 are respectively connected to pins 7 and 6 of chip U1, and the other ends of the resistors R11 and R12 are respectively connected to C4 and C5. One end of R18 is connected to pin 7 of chip U2, and the other end of R18 is connected to C8. R11, R12, R18, C4, C5, and C8 form a low-pass filter for filtering to reduce interference.

2. A universal circuit for ABZ differential and ABZ encoder for low-speed vehicles according to claim 1, characterized in that: It also includes resistors R5, R10, and R17 for ensuring the minimum current required for the light-emitting diodes inside U1 and U2 to conduct. One end of the resistor R5 is connected between R2 and U1, and the other end of the resistor R5 is connected between R4 and U1; one end of the resistor R10 is connected between R6 and U1, and the other end of the resistor R10 is connected between R9 and U1; one end of the resistor R17 is connected between R13 and U2, and the other end of the resistor R17 is connected between R16 and U2.

3. The universal circuit for ABZ differential and ABZ encoder of a low-speed vehicle according to claim 1, characterized in that: It also includes resistors R3, R7, and R15. One end of the resistor R3 is connected between R2 and the motor, and the other end of the resistor R3 is connected between R4 and the motor; one end of the resistor R7 is connected between R6 and the motor, and the other end of the resistor R7 is connected between R9 and the motor; one end of the resistor R15 is connected between R13 and the motor, and the other end of the resistor R15 is connected between R16 and the motor; R3, R7, and R15 are used to improve signal matching, reduce signal reflection, and stabilize the working state of the differential line pair.

4. A universal circuit for ABZ differential and ABZ encoder for low-speed vehicles according to claim 1, characterized in that: It also includes C1, C2, C3, C6, and C7 for filtering. The capacitor C1 is connected between R5 and U1, the capacitor C2 is connected between R10 and U1, the capacitor C6 is connected between R17 and U2, the capacitor C3 is connected to pin 8 of U1, and C7 is connected to pin 8 of U2.

5. The universal circuit for ABZ differential and ABZ encoder of a low-speed vehicle according to claim 1, characterized in that: The chips U1 and U2 are both dual-channel optocouplers.

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