Servo motor speed measuring circuit based on incremental encoder

Abstract

The invention provides a servo motor speed measuring circuit based on an incremental encoder, and belongs to the technical field of servo control, and the measuring circuit comprises a resistor R1, capacitors C1 to C3, a digital processor U1, a level conversion transceiver U2 and an incremental encoder U3. Compared with a general processing circuit, the circuit has the advantages of low circuit complexity, high stability, strong practicability and low cost.

Description

Technical Field

[0001] This invention belongs to the field of servo control technology, specifically relating to a servo motor speed measurement circuit based on an incremental encoder. Background Technology

[0002] In the application of servo control technology, the main methods for measuring servo motor speed include Hall sensor speed measurement, laser Doppler speed measurement, and incremental encoder pulse signal measurement. Different measurement methods require different processing circuits.

[0003] In the measurement method of incremental encoder pulse signals, the common processing circuit uses a phase decoding module (D flip-flop or dedicated decoding chip) to perform direction identification and counting. The direction identification and counting information is then transmitted to a processor via a bus for speed calculation and subsequent speed loop control. This processing circuit places very high demands on the selection of the phase decoding module. First, the decoding rate of the phase decoding module must match the highest frequency of the incremental encoder. Second, it must ensure that the output level of the phase decoding module is consistent with the input level of the subsequent processor; a level conversion chip may be necessary. Finally, to ensure circuit stability in complex environments, anti-interference enhancement design is required. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a method for measuring the speed of a servo motor based on an incremental encoder, which measures the speed of the servo motor by demodulating the pulse signal output by the incremental encoder.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a servo motor speed measurement circuit based on an incremental encoder, the measurement circuit comprising: It consists of resistor R1, capacitors C1 to C3, digital processor U1, level conversion transceiver U2, and incremental encoder U3.

[0006] The enhanced index interface EQEP1I of digital processor U1 is connected to the output interface 1A1 of level converter transceiver U2; the enhanced input interface EQEP1B of digital processor U1 is connected to the output interface 1A2 of level converter transceiver U2; the enhanced input interface EQEP1A of digital processor U1 is connected to the output interface 1A3 of level converter transceiver U2; resistor R1 is connected between the direction signal 1DIR of level converter transceiver U2 and power ground; capacitor C1 is connected between power supply VCC3V3 and power ground; capacitor C2 is connected between power supply 5V and power ground; input interface 1B1 of level converter transceiver U2 is connected to the output interface Z of incremental encoder U3; input interface 1B2 of level converter transceiver U2 is connected to the output interface B of incremental encoder U3; input interface 1B3 of level converter transceiver U2 is connected to the output interface A of incremental encoder U3; and capacitor C3 is connected between power supply 5V and power ground.

[0007] The servo motor speed measurement circuit based on incremental encoder provided by the present invention also has the following technical feature: the digital processor U1 is a digital processor with an orthogonal decoding unit.

[0008] The servo motor speed measurement circuit based on an incremental encoder provided by the present invention also has the following technical feature: the incremental encoder is a three-wire output incremental encoder.

[0009] Beneficial effects: The servo motor speed measurement circuit provided by this invention has lower circuit complexity, higher stability, stronger practicality, and lower cost compared to general processing circuits. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the circuit provided in an embodiment of the present invention. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0013] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0014] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0015] The terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of these terms in this invention based on the specific circumstances.

[0016] like Figure 1 As shown, this embodiment of the invention provides a servo motor speed measurement circuit based on an incremental encoder, the measurement circuit comprising: It consists of resistor R1, capacitors C1 to C3, digital processor U1, level conversion transceiver U2, and incremental encoder U3.

[0017] The enhanced index interface EQEP1I of digital processor U1 is connected to the output interface 1A1 of level converter transceiver U2; the enhanced input interface EQEP1B of digital processor U1 is connected to the output interface 1A2 of level converter transceiver U2; the enhanced input interface EQEP1A of digital processor U1 is connected to the output interface 1A3 of level converter transceiver U2; resistor R1 is connected between the direction signal 1DIR of level converter transceiver U2 and power ground; capacitor C1 is connected between power supply VCC3V3 and power ground; capacitor C2 is connected between power supply 5V and power ground; input interface 1B1 of level converter transceiver U2 is connected to the output interface Z of incremental encoder U3; input interface 1B2 of level converter transceiver U2 is connected to the output interface B of incremental encoder U3; input interface 1B3 of level converter transceiver U2 is connected to the output interface A of incremental encoder U3; and capacitor C3 is connected between power supply 5V and power ground.

[0018] In some embodiments, the digital processor U1 is a digital processor with an orthogonal decoding unit.

[0019] In some embodiments, the incremental encoder is a three-wire output incremental encoder.

[0020] The working principle of the circuit provided in any of the foregoing embodiments is as follows: When the servo motor drives the incremental encoder U3 to rotate, the incremental encoder U3 outputs quadrature encoding signals A and B, and a pulse index signal Z. After passing through the level conversion transceiver U2, the quadrature encoding signals A, B, and Z are converted into DSP-compatible 3.3V TTL signals for recognition by the DSP's eQEP module. The eQEP module measures the motor speed by judging the pulse frequency of the quadrature encoding signals A and B, and measures the direction of motor rotation by judging the phase relationship between the quadrature encoding signals A and B.

[0021] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A servo motor speed measurement circuit based on an incremental encoder, characterized in that, The measurement circuit includes: Resistor R1, capacitors C1 to C3, digital processor U1, level shift transceiver U2, and incremental encoder U3, The enhanced index interface EQEP1I of digital processor U1 is connected to the output interface 1A1 of level converter transceiver U2; the enhanced input interface EQEP1B of digital processor U1 is connected to the output interface 1A2 of level converter transceiver U2; the enhanced input interface EQEP1A of digital processor U1 is connected to the output interface 1A3 of level converter transceiver U2; resistor R1 is connected between the direction signal 1DIR of level converter transceiver U2 and power ground; capacitor C1 is connected between power supply VCC3V3 and power ground; capacitor C2 is connected between power supply 5V and power ground; input interface 1B1 of level converter transceiver U2 is connected to the output interface Z of incremental encoder U3; input interface 1B2 of level converter transceiver U2 is connected to the output interface B of incremental encoder U3; input interface 1B3 of level converter transceiver U2 is connected to the output interface A of incremental encoder U3; and capacitor C3 is connected between power supply 5V and power ground.

2. The servo motor speed measurement circuit based on an incremental encoder according to claim 1, characterized in that, The digital processor U1 is a digital processor with an orthogonal decoding unit.

3. The servo motor speed measurement circuit based on an incremental encoder according to claim 1, characterized in that, The incremental encoder is a three-wire output incremental encoder.

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