Speed measuring device and speed measuring method for speed fluctuation system

Abstract

The invention discloses a speed measuring device and a speed measuring method for a speed fluctuation system. The speed measuring device comprises an encoder, a filter circuit, an isolation circuit, a microcontroller and a communication circuit which are installed on a speed fluctuation system to be measured. The output end of the encoder is connected with the input end of the filter circuit, the output end of the filter circuit is connected with the input end of the isolation circuit, and the output end of the isolation circuit is connected with the microcontroller; the input end of the communication circuit is connected with the microcontroller, and the output end of the communication circuit is connected with an external server; wherein the encoder is used for detecting rotation of a speed fluctuation system to be detected and outputting a first pulse signal; the filter circuit is used for filtering the first pulse signal to obtain a second pulse signal; the isolation circuit is used for performing electrical isolation and level conversion on the second pulse signal to obtain a third pulse signal; and the microcontroller is used for calculating the instantaneous rotating speed of the to-be-measured speed fluctuation system based on the third pulse signal.

Description

Technical Field

[0001] The present application relates to the field of industrial automation control technology, and in particular to a speed measuring device and a speed measuring method for a speed fluctuation system. Background Art

[0002] With the rapid development of industrial automation technology, industrial production has increasingly higher requirements for the accuracy and stability of speed measurement systems. Encoders, as an important speed measurement device, are widely used in a variety of applications to achieve high-precision and high-stability speed monitoring. However, existing encoder speed measurement systems face multiple challenges when dealing with large speed fluctuations.

[0003] First, insufficient speed measurement accuracy is one of the main problems. The current encoder system cannot effectively reflect the average speed in a fluctuating system, resulting in large fluctuations in speed measurement results, which affects performance in practical applications. Secondly, the system has poor stability and is easily affected by external interference factors, resulting in inaccurate speed measurement results, which manifests as significant jumps in speed values. This not only reduces the reliability of speed measurement, but may also affect the decision-making of subsequent control systems.

[0004] Therefore, it is urgent to propose an improvement plan to improve the speed measurement accuracy and stability of the encoder in the speed fluctuation system and provide more reliable technical support for industrial automation. Summary of the invention

[0005] To this end, the present application provides a speed measuring device and a speed measuring method for a speed fluctuation system to solve the problems of low speed measurement accuracy and poor speed measurement stability of existing encoders in speed fluctuation systems.

[0006] In a first aspect, the present application provides a speed measuring device for a speed fluctuation system, the speed measuring device comprising an encoder, a filter circuit, an isolation circuit, a microcontroller and a communication circuit installed on the speed fluctuation system to be measured;

[0007] The output end of the encoder is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the isolation circuit, and the output end of the isolation circuit is connected to the microcontroller;

[0008] The input end of the communication circuit is connected to the microcontroller, and the output end of the communication circuit is connected to an external server;

[0009] Among them, the encoder is used to detect the rotation of the speed fluctuation system to be measured and output a first pulse signal; the filtering circuit is used to filter the first pulse signal to obtain a second pulse signal; the isolation circuit is used to electrically isolate and level-convert the second pulse signal to obtain a third pulse signal; the microcontroller is used to calculate the instantaneous rotational speed of the speed fluctuation system to be measured based on the third pulse signal.

[0010] Optionally, the encoder is an incremental encoder.

[0011] Optionally, the filter circuit includes an A-phase filter circuit and a B-phase filter circuit;

[0012] The A phase of the encoder is connected to the input end of the A phase filter circuit, the B phase of the encoder is connected to the input end of the B phase filter circuit, and the output end of the A phase filter circuit and the output end of the B phase filter circuit are respectively connected to the input end of the isolation circuit.

[0013] Optionally, the isolation circuit includes an A-phase isolation circuit and a B-phase isolation circuit;

[0014] The input end of the A-phase isolation circuit is connected to the output end of the A-phase filter circuit, the input end of the B-phase isolation circuit is connected to the output end of the B-phase filter circuit, and the output end of the A-phase isolation circuit and the output end of the B-phase isolation circuit are respectively connected to the microcontroller.

[0015] Optionally, the A-phase filtering circuit includes a sixtieth resistor R60 and a fifty-second capacitor C52, and the A-phase isolation circuit includes a first photocoupler U36;

[0016] One end of the sixtieth resistor R60 is connected to the signal common end of the encoder, and the other end of the sixtieth resistor R60 is divided into four paths, the first path is connected to one end of the fifty-second capacitor C52, the second path is connected to one end of the sixty-fourth resistor R64, the third path is connected to the cathode of the twenty-third diode D23, and the fourth path is connected to the second pin of the first photocoupler U36;

[0017] The other end of the fifty-second capacitor C52, the other end of the sixty-fourth resistor R64 and the anode of the twenty-third diode D23 are all connected to phase A of the encoder;

[0018] Pin 1 and pin 4 of the first photocoupler U36 are both suspended; pin 3 of the first photocoupler U36 is connected to phase A of the encoder; pin 5 of the first photocoupler U36 is grounded, pin 6 of the first photocoupler U36 is divided into four paths, the first path is connected to one end of the forty-sixth capacitor C46, ​​the second path is connected to the cathode of the twenty-first diode D21, the third path is connected to one end of the sixty-second resistor R62, and the fourth path is connected to the microcontroller; pin 7 of the first photocoupler U36 is connected to pin 8 of the first photocoupler U36; pin 8 of the first photocoupler U36 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-sixth capacitor C46, ​​and the third path is connected to one end of the fifty-eighth resistor R58; the other end of the fifty-eighth resistor R58 is divided into two paths, one path is connected to the anode of the twenty-first diode D21, and the other path is connected to the other end of the sixty-second resistor R62.

[0019] Optionally, the B-phase filtering circuit includes a sixty-eighth resistor R68 and a fifty-fourth capacitor C54, and the B-phase isolation circuit includes a second photocoupler U38;

[0020] One end of the sixty-eighth resistor R68 is connected to the signal common end of the encoder, and the other end of the sixty-eighth resistor R68 is divided into four paths, the first path is connected to one end of the fifty-fourth capacitor C54, the second path is connected to one end of the seventy-second resistor R72, the third path is connected to the cathode of the twenty-seventh diode D27, and the fourth path is connected to the second pin of the second photocoupler U38;

[0021] The other end of the fifty-fourth capacitor C54, the other end of the seventy-second resistor R72, and the anode of the twenty-seventh diode D27 are all connected to phase B of the encoder;

[0022] Pin 1 and pin 4 of the second photocoupler U38 are both suspended; pin 3 of the second photocoupler U38 is connected to phase B of the encoder; pin 5 of the second photocoupler U38 is grounded, pin 6 of the second photocoupler U38 is divided into four paths, the first path is connected to one end of the forty-eighth capacitor C48, the second path is connected to the cathode of the twenty-fifth diode D25, the third path is connected to one end of the seventieth resistor R70, and the fourth path is connected to the microcontroller; pin 7 of the second photocoupler U38 is connected to pin 8 of the second photocoupler U38; pin 8 of the second photocoupler U38 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-eighth capacitor C48, and the third path is connected to one end of the sixty-sixth resistor R66; the other end of the sixty-sixth resistor R66 is divided into two paths, one path is connected to the anode of the twenty-fifth diode D25, and the other path is connected to the other end of the seventieth resistor R70.

[0023] Optionally, the microcontroller is a STM32F407ZET6 microcontroller.

[0024] In a second aspect, the present application provides a speed measurement method for a speed fluctuation system, the method comprising:

[0025] Detecting the rotation of the speed fluctuation system to be measured by an encoder and outputting a first pulse signal;

[0026] Filtering the first pulse signal through a filtering circuit to obtain a second pulse signal;

[0027] Performing electrical isolation and level conversion on the second pulse signal through an isolation circuit to obtain a third pulse signal;

[0028] Based on the third pulse signal, the instantaneous rotation speed of the speed fluctuation system to be measured is calculated by a microcontroller.

[0029] Optionally, the microcontroller calculates the instantaneous rotation speed of the encoder according to the formula S=n / (T1+T2+T3+...+Tn) / C, thereby obtaining the instantaneous rotation speed of the speed fluctuation system to be measured;

[0030] Wherein, S represents the instantaneous rotation speed of the encoder, n represents the number of pulses in each fluctuation period, T1, T2, ..., Tn represent the duration of the interval between adjacent pulses, and C represents the number of pulses per revolution of the encoder.

[0031] Compared with the prior art, this application has at least the following beneficial effects:

[0032] The present application adopts a speed measuring device for a speed fluctuation system, comprising an encoder, a filter circuit, an isolation circuit, a microcontroller and a communication circuit installed on the speed fluctuation system to be measured; the output end of the encoder is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the isolation circuit, and the output end of the isolation circuit is connected to the microcontroller; the input end of the communication circuit is connected to the microcontroller, and the output end of the communication circuit is connected to an external server. Among them, the encoder is used to detect the rotation of the speed fluctuation system to be measured and output a first pulse signal; the filtering circuit is used to filter the first pulse signal to obtain a second pulse signal. By filtering the first pulse signal output by the encoder through the filtering circuit, the interference signal and the noise signal in the pulse signal can be reduced, thereby improving the speed measurement accuracy; the isolation circuit is used to electrically isolate and level-convert the second pulse signal to obtain a third pulse signal. The isolation circuit can protect the microcontroller from external interference, enhance the stability of the speed measuring device, help avoid large jumps in the speed measurement results, and improve the measurement reliability of the speed measuring device; the microcontroller is used to calculate the instantaneous rotation speed of the speed fluctuation system to be measured based on the third pulse signal. The microcontroller calculates the instantaneous rotation speed based on the filtered and isolated third pulse signal, so that the speed measurement of the speed measuring device is smoother and more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more intuitively illustrate the prior art and the present application, exemplary drawings are given below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing the present application; for example, those skilled in the art are capable of easily making conventional adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components) based on the technical concepts and exemplary drawings disclosed in the present application.

[0034] Figure 1 A circuit principle block diagram of a speed measuring device for a speed fluctuation system provided in an embodiment of the present application;

[0035] Figure 2 A circuit schematic diagram of an A-phase filter circuit and an A-phase isolation circuit provided in an embodiment of the present application;

[0036] Figure 3 A circuit schematic diagram of a B-phase filter circuit and a B-phase isolation circuit provided in an embodiment of the present application;

[0037] Figure 4 A circuit schematic diagram of a microcontroller provided in an embodiment of the present application;

[0038] Figure 5 A circuit schematic diagram of a communication circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The present application is further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0040] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0041] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this application are usually used to indicate the general relative position relationship for the purpose of intuitive understanding by referring to the drawings, and are not absolute limitations on the position relationship in the actual product.

[0042] A speed fluctuation system is a system whose speed or rotational speed fluctuates or changes significantly during operation. The speed or rotational speed fluctuation of a speed fluctuation system may be caused by a variety of factors such as load changes, environmental factors, mechanical wear, control systems, power supply fluctuations, etc. Speed ​​fluctuation systems are common in motor-driven mechanical equipment, pumps, fans, etc.

[0043] like Figure 1 As shown, a speed measuring device for a speed fluctuation system includes an encoder installed on the speed fluctuation system to be measured, a filter circuit, an isolation circuit, a microcontroller and a communication circuit;

[0044] The output end of the encoder is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the isolation circuit, and the output end of the isolation circuit is connected to the microcontroller;

[0045] The input end of the communication circuit is connected to the microcontroller, and the output end of the communication circuit is connected to an external server;

[0046] Among them, the encoder is used to detect the rotation of the speed fluctuation system to be measured and output a first pulse signal; the filtering circuit is used to filter the first pulse signal to obtain a second pulse signal; the isolation circuit is used to electrically isolate and level-convert the second pulse signal to obtain a third pulse signal; the microcontroller is used to calculate the instantaneous rotational speed of the speed fluctuation system to be measured based on the third pulse signal.

[0047] It should be noted that the encoder is used to detect rotation and output a first pulse signal.

[0048] For the pulse signal of the encoder, due to the influence of line or space interference, noise is easily generated on the pulse signal line. In view of this situation, the filter circuit removes the burrs in the first pulse signal to obtain the second pulse signal.

[0049] The second pulse signal is electrically isolated and level-converted by an isolation circuit to obtain a third pulse signal, and the third pulse signal is connected to an encoder interface of the microcontroller.

[0050] The microcontroller uses a high-performance 32-bit ARM microprocessor. The encoder hardware interface function and high-speed timer timing function of the on-chip timer are used to collect encoder pulse signals, pulse interval timing, data processing, speed calculation and other functions. The rich on-chip peripherals can also meet other functional requirements. It is the main controller for core algorithms, control output and other functions.

[0051] The speed measuring device for a speed fluctuation system provided by the present application can effectively filter out interference, make the subsequent signal acquisition and processing more stable, and improve the accuracy of speed measurement; the speed fluctuation can be effectively filtered out to make the measured speed value more stable; the quality requirements for the encoder are reduced; it is suitable for use in various harsh environments; and the direction of rotation of the encoder can be directly output.

[0052] In this embodiment, the key to realizing speed measurement of the speed fluctuation system through the speed measuring device lies in: anti-interference processing of multi-stage encoder pulse signals; fast measurement response in the initial period of rotation; effective filtering of the rotation speed and smooth feedback of the speed, which provides favorable conditions and support for the closed-loop control of the system.

[0053] In an embodiment of the present application, a speed measuring device for a speed fluctuation system includes an encoder, a filter circuit, an isolation circuit, a microcontroller and a communication circuit installed on the speed fluctuation system to be measured; the output end of the encoder is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the isolation circuit, and the output end of the isolation circuit is connected to the microcontroller; the input end of the communication circuit is connected to the microcontroller, and the output end of the communication circuit is connected to an external server. Among them, the encoder is used to detect the rotation of the speed fluctuation system to be measured and output a first pulse signal; the filtering circuit is used to filter the first pulse signal to obtain a second pulse signal. By filtering the first pulse signal output by the encoder through the filtering circuit, the interference signal and the noise signal in the pulse signal can be reduced, thereby improving the speed measurement accuracy; the isolation circuit is used to electrically isolate and level-convert the second pulse signal to obtain a third pulse signal. The isolation circuit can protect the microcontroller from external interference, enhance the stability of the speed measuring device, help avoid large jumps in the speed measurement results, and improve the measurement reliability of the speed measuring device; the microcontroller is used to calculate the instantaneous rotation speed of the speed fluctuation system to be measured based on the third pulse signal. The microcontroller calculates the instantaneous rotation speed based on the filtered and isolated third pulse signal, so that the speed measurement of the speed measuring device is smoother and more accurate.

[0054] In this embodiment, the encoder is an incremental encoder.

[0055] In this embodiment, the filter circuit includes an A-phase filter circuit and a B-phase filter circuit;

[0056] The A phase of the encoder is connected to the input end of the A phase filter circuit, the B phase of the encoder is connected to the input end of the B phase filter circuit, and the output end of the A phase filter circuit and the output end of the B phase filter circuit are respectively connected to the input end of the isolation circuit.

[0057] In this embodiment, the isolation circuit includes an A-phase isolation circuit and a B-phase isolation circuit;

[0058] The input end of the A-phase isolation circuit is connected to the output end of the A-phase filter circuit, the input end of the B-phase isolation circuit is connected to the output end of the B-phase filter circuit, and the output end of the A-phase isolation circuit and the output end of the B-phase isolation circuit are respectively connected to the microcontroller.

[0059] like Figure 2 As shown, in this embodiment, the A-phase filter circuit includes a sixtieth resistor R60 and a fifty-second capacitor C52, and the A-phase isolation circuit includes a first photocoupler U36;

[0060] One end of the sixtieth resistor R60 is connected to the signal common end of the encoder, and the other end of the sixtieth resistor R60 is divided into four paths, the first path is connected to one end of the fifty-second capacitor C52, the second path is connected to one end of the sixty-fourth resistor R64, the third path is connected to the cathode of the twenty-third diode D23, and the fourth path is connected to the second pin of the first photocoupler U36;

[0061] The other end of the fifty-second capacitor C52, the other end of the sixty-fourth resistor R64 and the anode of the twenty-third diode D23 are all connected to phase A of the encoder;

[0062] Pin 1 and pin 4 of the first photocoupler U36 are both suspended; pin 3 of the first photocoupler U36 is connected to phase A of the encoder; pin 5 of the first photocoupler U36 is grounded, pin 6 of the first photocoupler U36 is divided into four paths, the first path is connected to one end of the forty-sixth capacitor C46, ​​the second path is connected to the cathode of the twenty-first diode D21, the third path is connected to one end of the sixty-second resistor R62, and the fourth path is connected to the microcontroller; pin 7 of the first photocoupler U36 is connected to pin 8 of the first photocoupler U36; pin 8 of the first photocoupler U36 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-sixth capacitor C46, ​​and the third path is connected to one end of the fifty-eighth resistor R58; the other end of the fifty-eighth resistor R58 is divided into two paths, one path is connected to the anode of the twenty-first diode D21, and the other path is connected to the other end of the sixty-second resistor R62.

[0063] like Figure 2 As shown, the 1st and 4th pins of the optocoupler isolation chip U36 are suspended pins, the 2nd pin of U36 is marked as node C, and the 3rd pin of U36 is marked as node D. Figure 2 The two ends of C52, R64, and D23 are connected to nodes C and D respectively, one end of R60 is connected to node C, and the other end of R60 is connected to the common end of the encoder signal. Encoder signal A is connected to node D. Pins 7 and 8 of U36 are connected to the positive pole of the 5V power supply, one end of resistor R58 is connected to the positive pole of the 5V power supply, the other end of R58 is connected to one end of D21 and R62, and the other end of D21, the other end of R62, and pin 6 of U36 are connected to pin 96 of the main controller U62A.

[0064] It should be noted that the A phase of the encoder is represented as LBMQA, and the signal common end of the encoder is represented as BMQ COM.

[0065] It should be noted that the third path of the 6th pin of the first photocoupler U36 is connected to the 96th pin of the microcontroller STM32F407ZET6.

[0066] like Figure 3 As shown, in this embodiment, the B-phase filter circuit includes a sixty-eighth resistor R68 and a fifty-fourth capacitor C54, and the B-phase isolation circuit includes a second photocoupler U38;

[0067] One end of the sixty-eighth resistor R68 is connected to the signal common end of the encoder, and the other end of the sixty-eighth resistor R68 is divided into four paths, the first path is connected to one end of the fifty-fourth capacitor C54, the second path is connected to one end of the seventy-second resistor R72, the third path is connected to the cathode of the twenty-seventh diode D27, and the fourth path is connected to the second pin of the second photocoupler U38;

[0068] The other end of the fifty-fourth capacitor C54, the other end of the seventy-second resistor R72, and the anode of the twenty-seventh diode D27 are all connected to phase B of the encoder;

[0069] Pin 1 and pin 4 of the second photocoupler U38 are both suspended; pin 3 of the second photocoupler U38 is connected to phase B of the encoder; pin 5 of the second photocoupler U38 is grounded, pin 6 of the second photocoupler U38 is divided into four paths, the first path is connected to one end of the forty-eighth capacitor C48, the second path is connected to the cathode of the twenty-fifth diode D25, the third path is connected to one end of the seventieth resistor R70, and the fourth path is connected to the microcontroller; pin 7 of the second photocoupler U38 is connected to pin 8 of the second photocoupler U38; pin 8 of the second photocoupler U38 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-eighth capacitor C48, and the third path is connected to one end of the sixty-sixth resistor R66; the other end of the sixty-sixth resistor R66 is divided into two paths, one path is connected to the anode of the twenty-fifth diode D25, and the other path is connected to the other end of the seventieth resistor R70.

[0070] like Figure 3 As shown, the 1st and 4th pins of the optocoupler isolation chip U38 are suspended pins, the 2nd pin of U38 is marked as node E, and the 3rd pin of U38 is marked as node F. Figure 3The two ends of C54, R72, and D27 are connected to nodes E and F respectively, one end of R68 is connected to node E, and the other end of R68 is connected to the common end of the encoder signal. Encoder signal B is connected to node F. Pins 7 and 8 of U38 are connected to the positive pole of the 5V power supply, one end of resistor R66 is connected to the positive pole of the 5V power supply, the other end of R66 is connected to one end of D25 and R70, and the other end of D25, the other end of R70, and pin 6 of U38 are connected to pin 97 of the main controller U62A.

[0071] It should be noted that the A phase of the encoder is represented as LBMQA, and the signal common end of the encoder is represented as BMQ COM.

[0072] It should be noted that the third path of the 6th pin of the first photocoupler U36 is connected to the 96th pin of the microcontroller STM32F407ZET6.

[0073] like Figure 4 As shown, in this embodiment, the microcontroller is a microcontroller STM32F407ZET6.

[0074] like Figure 5 As shown, in this embodiment, the communication circuit includes a digital isolation chip U10;

[0075] The 1st and 16th pins of the digital isolation chip U10 are connected to the voltage output terminal; the 2nd, 7th, 8th, 9th, 10th and 15th pins of the digital isolation chip U10 are all grounded; the 3rd pin of the digital isolation chip U10 is connected to the 70th pin of the microcontroller STM32F407ZET6; the 4th pin of the digital isolation chip U10 is connected to the 78th pin of the microcontroller STM32F407ZET6; the 5th pin of the digital isolation chip U10 is connected to the 4th pin of the digital isolation chip U10; the 6th pin of the digital isolation chip U10 is connected to the 77th pin of the microcontroller STM32F407ZET6; the 11th and 14th pins of the digital isolation chip U10 are both suspended; the 12th pin of the digital isolation chip U10 is connected to one end of the seventeenth resistor R17; the 13th pin of the digital isolation chip U10 is connected to one end of the nineteenth resistor R19;

[0076] The other end of the seventeenth resistor R17 is divided into five paths, the first path is connected to one end of the sixteenth resistor R16, the second path is connected to one end of the eighteenth resistor R18, the third path is connected to the cathode of the thirteenth diode U13, the fourth path is connected to one end of the eighth diode D8, and the fifth path is connected to one end of the eleventh fuse U11; the other end of the sixteenth resistor R16 is connected to the voltage output end; the other end of the eleventh fuse U11 is connected to the A port of the external server;

[0077] The other end of the nineteenth resistor R19 is divided into five paths, the first path is connected to the other end of the eighteenth resistor R18, the second path is connected to one end of the twentieth resistor R20, the third path is connected to the other end of the eighth diode D8, the fourth path is connected to the cathode of the fourteenth diode U14, and the fifth path is connected to one end of the twelfth fuse U12; the other end of the twelfth fuse U12 is connected to the B port of the external server;

[0078] The other end of the twentieth resistor R20, the anode of the thirteenth diode U13, and the anode of the fourteenth diode U14 are all grounded.

[0079] like Figure 5 As shown, the communication circuit is an RS485 communication interface circuit, which consists of the main interface chip U10 and peripheral circuits. Pin 6 of U10 is connected to Figure 3 Connect the 77th pin of U62A and the 5th and 4th pin of U10 to Figure 4 Pin 78 of U62A (microcontroller STM32F407ZET6) and pin 3 of U10 are connected to Figure 4 In the figure, the 70th pin of U62A, the 1st and 16th pins of U10 are connected to VCC, the 2nd, 7th, 8th, 9th, 10th and 15th pins of U10 are connected to the ground, the 12th pin of U10 is connected to one end of R17, and the other end of R17 is marked as the first node, the 13th pin of U10 is connected to one end of R19, and the other end of R19 is marked as the second node, one end of R16 is connected to the first node, the other end of R61 is connected to VCC, the two ends of R18 are connected to the first node and the second node respectively, one end of R20 is connected to the second node, and the other end of R20 is connected to the ground, one end of U13 is connected to the first node, and the other end of U13 is connected to the ground, the two ends of D8 are connected to the first node and the second node respectively, one end of U11 is connected to the first node, and the other end of U11 is the external communication connection port A. One end of U12 is connected to the second node, and the other end of U12 is the external communication connection port B. A and B are RS485 communication interfaces.

[0080] It should be noted that the model of the digital isolation chip U10 is IS03082DWR.

[0081] The thirteenth diode U13 and the fourteenth diode U14 are both unidirectional TVS transient suppression diodes, and the models of the thirteenth diode U13 and the fourteenth diode U14 are both SMF5.0A.

[0082] The eighth diode D8 is a TVS bidirectional diode, and the model of the eighth diode D8 is SMF5.0CA.

[0083] The models of the eleventh fuse U11 and the twelfth fuse U12 are both SMD08052B020TF.

[0084] In addition, an embodiment of the present application further provides a speed measurement method for a speed fluctuation system, comprising:

[0085] Detecting the rotation of the speed fluctuation system to be measured by an encoder and outputting a first pulse signal;

[0086] Filtering the first pulse signal through a filtering circuit to obtain a second pulse signal;

[0087] Performing electrical isolation and level conversion on the second pulse signal through an isolation circuit to obtain a third pulse signal;

[0088] Based on the third pulse signal, the instantaneous rotation speed of the speed fluctuation system to be measured is calculated by a microcontroller.

[0089] In this embodiment, the microcontroller calculates the instantaneous speed of the encoder according to the formula S=n / (T1+T2+T3+...+Tn) / C, and then obtains the instantaneous speed of the speed fluctuation system to be measured;

[0090] Wherein, S represents the instantaneous rotation speed of the encoder, n represents the number of pulses in each fluctuation period, T1, T2, ..., Tn represent the duration of the interval between adjacent pulses, and C represents the number of pulses per revolution of the encoder.

[0091] It should be noted that the encoder calculates the time interval between each pulse recorded in a fluctuation cycle, and calculates the rotation speed after taking the average value.

[0092] The speed calculation at the beginning of the encoder rotation is divided into several small parts in each fluctuation cycle. When the encoder pulse number reaches the number of each small part, the speed calculation can be performed, and the value is accumulated until the pulse number reaches the maximum pulse number in the fluctuation cycle, and the above formula S = n / (T1+T2+T3+...+Tn) / C can be used for calculation.

[0093] The technical features of the above embodiments can be combined arbitrarily as long as there is no contradiction in the combination of these technical features. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A speed measuring device for a speed fluctuation system, characterized in that: The speed measuring device comprises an encoder, a filter circuit, an isolation circuit, a microcontroller and a communication circuit installed on the speed fluctuation system to be measured; The output end of the encoder is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the isolation circuit, and the output end of the isolation circuit is connected to the microcontroller; The input end of the communication circuit is connected to the microcontroller, and the output end of the communication circuit is connected to an external server; Among them, the encoder is used to detect the rotation of the speed fluctuation system to be measured and output a first pulse signal; the filtering circuit is used to filter the first pulse signal to obtain a second pulse signal; the isolation circuit is used to electrically isolate and level-convert the second pulse signal to obtain a third pulse signal; the microcontroller is used to calculate the instantaneous rotational speed of the speed fluctuation system to be measured based on the third pulse signal.

2. A speed measuring device for a speed fluctuation system according to claim 1, characterized in that: The encoder is an incremental encoder.

3. The speed measuring device for a speed fluctuation system according to claim 1, characterized in that: The filter circuit includes an A-phase filter circuit and a B-phase filter circuit; The A phase of the encoder is connected to the input end of the A phase filter circuit, the B phase of the encoder is connected to the input end of the B phase filter circuit, and the output end of the A phase filter circuit and the output end of the B phase filter circuit are respectively connected to the input end of the isolation circuit.

4. A speed measuring device for a speed fluctuation system according to claim 3, characterized in that: The isolation circuit includes an A-phase isolation circuit and a B-phase isolation circuit; The input end of the A-phase isolation circuit is connected to the output end of the A-phase filter circuit, the input end of the B-phase isolation circuit is connected to the output end of the B-phase filter circuit, and the output end of the A-phase isolation circuit and the output end of the B-phase isolation circuit are respectively connected to the microcontroller.

5. The speed measuring device for a speed fluctuation system according to claim 4, characterized in that: The A-phase filtering circuit includes a sixtieth resistor R60 and a fifty-second capacitor C52, and the A-phase isolation circuit includes a first photocoupler U36; One end of the sixtieth resistor R60 is connected to the signal common end of the encoder, and the other end of the sixtieth resistor R60 is divided into four paths, the first path is connected to one end of the fifty-second capacitor C52, the second path is connected to one end of the sixty-fourth resistor R64, the third path is connected to the cathode of the twenty-third diode D23, and the fourth path is connected to the second pin of the first photocoupler U36; The other end of the fifty-second capacitor C52, the other end of the sixty-fourth resistor R64 and the anode of the twenty-third diode D23 are all connected to phase A of the encoder; Pin 1 and pin 4 of the first photocoupler U36 are both suspended; pin 3 of the first photocoupler U36 is connected to phase A of the encoder; pin 5 of the first photocoupler U36 is grounded, pin 6 of the first photocoupler U36 is divided into four paths, the first path is connected to one end of the forty-sixth capacitor C46, ​​the second path is connected to the cathode of the twenty-first diode D21, the third path is connected to one end of the sixty-second resistor R62, and the fourth path is connected to the microcontroller; pin 7 of the first photocoupler U36 is connected to pin 8 of the first photocoupler U36; pin 8 of the first photocoupler U36 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-sixth capacitor C46, ​​and the third path is connected to one end of the fifty-eighth resistor R58; the other end of the fifty-eighth resistor R58 is divided into two paths, one path is connected to the anode of the twenty-first diode D21, and the other path is connected to the other end of the sixty-second resistor R62.

6. The speed measuring device for a speed fluctuation system according to claim 4, characterized in that: The B-phase filter circuit includes a sixty-eighth resistor R68 and a fifty-fourth capacitor C54, and the B-phase isolation circuit includes a second photocoupler U38; One end of the sixty-eighth resistor R68 is connected to the signal common end of the encoder, and the other end of the sixty-eighth resistor R68 is divided into four paths, the first path is connected to one end of the fifty-fourth capacitor C54, the second path is connected to one end of the seventy-second resistor R72, the third path is connected to the cathode of the twenty-seventh diode D27, and the fourth path is connected to the second pin of the second photocoupler U38; The other end of the fifty-fourth capacitor C54, the other end of the seventy-second resistor R72 and the anode of the twenty-seventh diode D27 are all connected to phase B of the encoder; Pin 1 and pin 4 of the second photocoupler U38 are both suspended; pin 3 of the second photocoupler U38 is connected to phase B of the encoder; pin 5 of the second photocoupler U38 is grounded, pin 6 of the second photocoupler U38 is divided into four paths, the first path is connected to one end of the forty-eighth capacitor C48, the second path is connected to the cathode of the twenty-fifth diode D25, the third path is connected to one end of the seventieth resistor R70, and the fourth path is connected to the microcontroller; pin 7 of the second photocoupler U38 is connected to pin 8 of the second photocoupler U38; pin 8 of the second photocoupler U38 is divided into three paths, the first path is connected to the 5V voltage output end, the second path is connected to the other end of the forty-eighth capacitor C48, and the third path is connected to one end of the sixty-sixth resistor R66; the other end of the sixty-sixth resistor R66 is divided into two paths, one path is connected to the anode of the twenty-fifth diode D25, and the other path is connected to the other end of the seventieth resistor R70.

7. The speed measuring device for a speed fluctuation system according to claim 1, characterized in that: The microcontroller is a microcontroller STM32F407ZET6.

8. The speed measuring device for a speed fluctuation system according to claim 7, characterized in that: The communication circuit includes a digital isolation chip U10; The 1st and 16th pins of the digital isolation chip U10 are connected to the voltage output terminal; the 2nd, 7th, 8th, 9th, 10th and 15th pins of the digital isolation chip U10 are all grounded; the 3rd pin of the digital isolation chip U10 is connected to the 70th pin of the microcontroller STM32F407ZET6; the 4th pin of the digital isolation chip U10 is connected to the 78th pin of the microcontroller STM32F407ZET6; the 5th pin of the digital isolation chip U10 is connected to the 4th pin of the digital isolation chip U10; the 6th pin of the digital isolation chip U10 is connected to the 77th pin of the microcontroller STM32F407ZET6; the 11th and 14th pins of the digital isolation chip U10 are both suspended; the 12th pin of the digital isolation chip U10 is connected to one end of the seventeenth resistor R17; the 13th pin of the digital isolation chip U10 is connected to one end of the nineteenth resistor R19; The other end of the seventeenth resistor R17 is divided into five paths, the first path is connected to one end of the sixteenth resistor R16, the second path is connected to one end of the eighteenth resistor R18, the third path is connected to the cathode of the thirteenth diode U13, the fourth path is connected to one end of the eighth diode D8, and the fifth path is connected to one end of the eleventh fuse U11; the other end of the sixteenth resistor R16 is connected to the voltage output end; the other end of the eleventh fuse U11 is connected to the A port of the external server; The other end of the nineteenth resistor R19 is divided into five paths, the first path is connected to the other end of the eighteenth resistor R18, the second path is connected to one end of the twentieth resistor R20, the third path is connected to the other end of the eighth diode D8, the fourth path is connected to the cathode of the fourteenth diode U14, and the fifth path is connected to one end of the twelfth fuse U12; the other end of the twelfth fuse U12 is connected to the B port of the external server; The other end of the twentieth resistor R20, the anode of the thirteenth diode U13, and the anode of the fourteenth diode U14 are all grounded.

9. A speed measurement method for a speed fluctuation system, using the speed measurement device according to any one of claims 1 to 8, characterized in that: The method comprises: Detecting the rotation of the speed fluctuation system to be measured by an encoder and outputting a first pulse signal; Filtering the first pulse signal through a filtering circuit to obtain a second pulse signal; Performing electrical isolation and level conversion on the second pulse signal through an isolation circuit to obtain a third pulse signal; Based on the third pulse signal, the instantaneous rotation speed of the speed fluctuation system to be measured is calculated by a microcontroller.

10. A speed measurement method for a speed fluctuation system according to claim 9, characterized in that: The microcontroller calculates the instantaneous speed of the encoder according to the formula S=n / (T1+T2+T3+...+Tn) / C, and then obtains the instantaneous speed of the speed fluctuation system to be measured; Wherein, S represents the instantaneous rotation speed of the encoder, n represents the number of pulses in each fluctuation period, T1, T2, ..., Tn represent the duration of the interval between adjacent pulses, and C represents the number of pulses per revolution of the encoder.

Images