阅读说明：本技术 一种电机转速指示系统 (Motor rotating speed indicating system ) 是由 崔延光 贾明昌 萧放 马英矫 丁国杰 杨小军 袁尧 张大霖 于 2020-04-26 设计创作，主要内容包括：本发明提供一种电机转速指示系统,控制器将转速根据实际需求转换成PWM波、方波或数字信号,再通过端口电路连接至监测设备,以此来指示电机系统运行速度；由此可见,本发明将模拟量输出、脉冲输出或通讯总线输出三种转速指示方法进行兼容设计,能够适配不同场景需求,是一种安全可靠低成本的转速指示方法。(The invention provides a motor rotating speed indicating system.A controller converts the rotating speed into PWM (pulse-width modulation) waves, square waves or digital signals according to actual requirements and then is connected to monitoring equipment through a port circuit so as to indicate the running speed of the motor system; therefore, the invention compatibly designs three rotating speed indicating methods of analog output, pulse output or communication bus output, can adapt to different scene requirements, and is a safe, reliable and low-cost rotating speed indicating method.)

1. A motor rotating speed indicating system is characterized by comprising a controller, a port circuit and monitoring equipment;

the controller is used for acquiring the rotating speed of the motor, and then converting the rotating speed into PWM waves, square waves or digital signals conforming to a preset communication protocol according to user requirements, wherein the duty ratio of the PWM waves is in direct proportion to the rotating speed, the frequency of the square waves is in direct proportion to the rotating speed, and different waveforms of the digital signals correspond to different rotating speeds;

the port circuit is used for increasing the voltage amplitude of the PWM wave, the square wave or the digital signal and then outputting the PWM wave, the square wave or the digital signal with the increased voltage amplitude to the monitoring equipment;

the monitoring equipment is used for analyzing the rotating speed of the motor according to the PWM wave, the square wave or the digital signal after the voltage amplitude is increased.

2. A motor speed indicating system as claimed in claim 1, wherein the controller comprises a speed detecting unit, a speed indicating selector, an analog output control unit, a pulse output control unit, a communication bus output control unit and a speed signal output unit;

the speed detection unit is used for acquiring the rotating speed of the motor;

the rotating speed indication selector is used for outputting the rotating speed of the motor to the analog quantity output control unit, the pulse output control unit or the communication bus output control unit according to the requirements of a user;

the analog quantity output control unit is used for converting the rotating speed into PWM waves;

the pulse output control unit is used for converting the rotating speed into square waves;

the communication bus output control unit is used for converting the rotating speed into a digital signal conforming to a preset communication protocol;

the rotating speed signal output unit is used for outputting PWM waves, square waves or digital signals.

3. A motor speed indicating system as claimed in claim 1, wherein the port circuit comprises resistors R1, R2, transistors Q1-Q3, digital VCC, and analog V_adcAnd a power selection switch S1;

one end of the resistor R1 is used as an input end for analyzing the rotating speed of the motor by PWM waves, square waves or digital signals, and the other end of the resistor R1 is connected with the base electrode of the triode Q1; the emitter of the triode Q1 is grounded, and the collector is connected with the base of the triode Q2; one end of the resistor R2 is connected with the collector of the triode Q1, and the other end is connected with the collector of the triode Q2; the emitter of the triode Q2 is connected with the emitter of the triode Q3 and is used as the output end of PWM wave, square wave or digital signal; the collector of the triode Q3 is grounded, and the base of the triode Q3 is connected with the collector of the triode Q1; the power selection switch S1 is used for connecting the collector of the triode Q2 with a digital power supply VCC or an analog power supply V according to the requirements of users_adcWhen the resistor R1 receives the PWM wave, the power selection switch S1 connects the collector of the transistor Q2 to the analog power V_adcOtherwise, the power selection switch S1 connects the collector of transistor Q2 to the digital power supply VCC.

Technical Field

The invention belongs to the field of speed indication of motor controllers, and particularly relates to a motor rotating speed indicating system.

Background

There are many methods for detecting the rotating speed of the motor, such as obtaining the rotating speed of the motor through calculation of a control system, obtaining the rotating speed of the motor by using a rotary transformer, monitoring the rotating speed by using a proximity sensor, an optical coupling isolation circuit and the like, and detecting the rotating speed by using a digital converter, an analog conditioning circuit, the rotary transformer and other devices; therefore, in the prior art, the rotation speed of the motor is usually measured as an unknown quantity, and there is only a technical means for indicating the rotation speed when the rotation speed of the motor is known. Therefore, a need exists for a safe, reliable, low-cost method of indicating rotational speed.

Disclosure of Invention

In order to solve the problems, the invention provides a motor rotating speed indicating system, which is compatible with three rotating speed indicating methods of analog output, pulse output or communication bus output and can adapt to different scene requirements.

A motor rotating speed indicating system comprises a controller, a port circuit and monitoring equipment;

the controller is used for acquiring the rotating speed of the motor, and then converting the rotating speed into PWM waves, square waves or digital signals conforming to a preset communication protocol according to user requirements, wherein the duty ratio of the PWM waves is in direct proportion to the rotating speed, the frequency of the square waves is in direct proportion to the rotating speed, and different waveforms of the digital signals correspond to different rotating speeds;

the port circuit is used for increasing the voltage amplitude of the PWM wave, the square wave or the digital signal and then outputting the PWM wave, the square wave or the digital signal with the increased voltage amplitude to the monitoring equipment;

the monitoring equipment is used for analyzing the rotating speed of the motor according to the PWM wave, the square wave or the digital signal after the voltage amplitude is increased.

Furthermore, the controller comprises a speed detection unit, a rotating speed indication selector, an analog output control unit, a pulse output control unit, a communication bus output control unit and a rotating speed signal output unit;

the speed detection unit is used for acquiring the rotating speed of the motor;

the rotating speed indication selector is used for outputting the rotating speed of the motor to the analog quantity output control unit, the pulse output control unit or the communication bus output control unit according to the requirements of a user;

the analog quantity output control unit is used for converting the rotating speed into PWM waves;

the pulse output control unit is used for converting the rotating speed into square waves;

the communication bus output control unit is used for converting the rotating speed into a digital signal conforming to a preset communication protocol;

the rotating speed signal output unit is used for outputting PWM waves, square waves or digital signals.

Furthermore, the port circuit comprises resistors R1 and R2, triodes Q1-Q3, a digital power supply VCC and an analog power supply V_adcAnd a power selection switch S1;

one end of the resistor R1 is used as an input end for analyzing the rotating speed of the motor by PWM waves, square waves or digital signals, and the other end of the resistor R1 is connected with the base electrode of the triode Q1; the emitter of the triode Q1 is grounded, and the collector is connected with the base of the triode Q2; one end of the resistor R2 is connected with the collector of the triode Q1, and the other end is connected with the collector of the triode Q2; the emitter of the triode Q2 is connected with the emitter of the triode Q3 and is used as the output end of PWM wave, square wave or digital signal; the collector of the triode Q3 is grounded, and the base of the triode Q3 is connected with the collector of the triode Q1; the power selection switch S1 is used for connecting the collector of the triode Q2 with a digital power supply VCC or an analog power supply V according to the requirements of users_adcWhen the resistor R1 receives the PWM wave, the power selection switch S1 connects the collector of the transistor Q2 to the analog power V_adcOtherwise, the power selection switch S1 connects the collector of transistor Q2 to the digital power supply VCC.

Has the advantages that:

the invention provides a motor rotating speed indicating system.A controller converts the rotating speed into PWM (pulse-width modulation) waves, square waves or digital signals according to actual requirements and then is connected to monitoring equipment through a port circuit so as to indicate the running speed of the motor system; therefore, the invention compatibly designs three rotating speed indicating methods of analog output, pulse output or communication bus output, can adapt to different scene requirements, and is a safe, reliable and low-cost rotating speed indicating method.

Drawings

FIG. 1 is a schematic block diagram of a motor speed indicating system according to the present invention;

FIG. 2 is a schematic diagram of a controller provided by the present invention;

FIG. 3 is a schematic diagram of a port circuit provided by the present invention;

FIG. 4 is a schematic diagram of an analog output indicating control waveform provided by the present invention;

FIG. 5 is a schematic diagram of a pulse output indication control waveform provided by the present invention;

FIG. 6 is a schematic diagram of an output indication control waveform of a communication bus according to the present invention.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

As shown in fig. 1, a motor speed indicating system includes a controller, a port circuit, and a monitoring device;

the controller is used for acquiring the rotating speed of the motor, and then converting the rotating speed into PWM waves, square waves or digital signals conforming to a preset communication protocol according to user requirements, wherein the duty ratio of the PWM waves is in direct proportion to the rotating speed, the frequency of the square waves is in direct proportion to the rotating speed, and different waveforms of the digital signals correspond to different rotating speeds;

the port circuit is used for increasing the voltage amplitude of the PWM wave, the square wave or the digital signal and then outputting the PWM wave, the square wave or the digital signal with the increased voltage amplitude to the monitoring equipment;

the monitoring equipment, such as the instrument panel, is used for analyzing the rotating speed of the motor according to the PWM wave, the square wave or the digital signal after the voltage amplitude is increased.

As shown in fig. 2, the controller includes a speed detection unit, a rotational speed indication selector, an analog output control unit, a pulse output control unit, a communication bus output control unit, and a rotational speed signal output unit; the system obtains the rotating speed through the speed detection unit, selects one of analog quantity speed measurement output, pulse speed measurement output or communication bus speed measurement output, enables a corresponding control mode, and finally outputs a corresponding signal through the control port Vin to indicate the system speed, wherein the functions of each part are as follows:

the speed detection unit is used for acquiring the rotating speed of the motor; it should be noted that the rotating speed of the motor of the present invention is an obtained variable, that is, the rotating speed is measured by an external device, such as a rotary transformer, a proximity sensor or an optical coupling isolation circuit, and then is input to the speed detection unit; that is, the invention indicates the rotating speed of the motor by deforming the rotating speed under the condition that the rotating speed of the motor is known;

the rotating speed indication selector is used for outputting the rotating speed of the motor to the analog quantity output control unit, the pulse output control unit or the communication bus output control unit according to the requirements of a user; it should be noted that the rotation speed indication selector is equivalent to a selection function in the program, and determines whether the rotation speed of the motor acquired by the speed detection unit is represented by an analog quantity, a pulse digital quantity or a communication signal;

the analog quantity output control unit is used for converting the rotating speed into PWM waves;

the pulse output control unit is used for converting the rotating speed into square waves;

the communication bus output control unit is used for converting the rotating speed into a digital signal conforming to a preset communication protocol;

the rotating speed signal output unit is used for outputting PWM waves, square waves or digital signals.

Therefore, in order to adapt to different scene requirements, the invention compatibly designs three speed measurement methods of an analog output control unit, a pulse output control unit or a communication bus output control unit; by using the circuit of the invention, the analog output indication rotating speed, the pulse output indication rotating speed or the communication output indication rotating speed can be realized only by switching different control parameters in the built-in software of the controller, wherein only one signal cable is used for communication when the circuit is used as the communication output indication.

As shown in fig. 3, the port circuit includes resistors R1 and R2, transistors Q1 to Q3, a digital power source VCC, and an analog power source V_adcAnd a power selection switch S1; wherein, the triode Q1-Q3, the resistor R1 and the R2 form a switch circuit;

one end of the resistor R1 is used as an input end for analyzing the rotating speed of the motor by PWM waves, square waves or digital signals, and the other end of the resistor R1 is connected with the base electrode of the triode Q1; the emitter of the triode Q1 is grounded, and the collector is connected with the base of the triode Q2; one end of the resistor R2 is connected with the collector of the triode Q1, and the other end is connected with the collector of the triode Q2; the emitter of the triode Q2 is connected with the emitter of the triode Q3 and is used as the output end of PWM wave, square wave or digital signal; the collector of the triode Q3 is grounded, and the base of the triode Q3 is connected with the collector of the triode Q1; the power selection switch S1 is used for connecting the collector of the triode Q2 with a digital power supply VCC or an analog power supply V according to the requirements of users_adcWhen the resistor R1 receives the PWM wave, the power selection switch S1 connects the collector of the transistor Q2 to the analog power V_adcOtherwise, the power selection switch S1 connects the collector of transistor Q2 to the digital power supply VCC.

That is, when the port circuit is used as the analog speed measurement output port, the power selection switch S₁Connecting an analog power supply V_adcWith I/O port of control chip (i.e. controller) at V_inA fixed frequency PWM wave is input, and the duty ratio of PWM is in direct proportion to the rotating speed. PWM waveform V of analog quantity speed measurement output port_outThe voltage amplitude after low-pass filtering is in direct proportion to the rotating speed, so that analog speed measurement is realized.

When the port circuit is used as the pulse velocity measurement output port, the power selection switch S₁The I/O port of the control chip is connected with a digital power supply VCC and is at V_inThe square wave with fixed duty ratio is input, and the frequency of the square wave is in direct proportion to the rotating speed. The monitoring equipment can measure the waveform V of the output port of the pulse velocity_outThe number of square waves of (A) is counted, andnow the pulse velocity measurement.

When the port circuit is used as a communication bus speed measurement output port, the power supply selection switch S₁The I/O port of the control chip is connected with a digital power supply VCC and is at V_inInputting data waveform with fixed communication protocol format. Monitoring equipment is to LIN communication bus speed measurement output port V_outThe data waveform is analyzed, and the speed measurement by using the communication bus is realized.

Further, when the analog speed measuring output port is used, the implementation steps are as follows:

1. power selection switch S₁Connecting an analog power supply V_adcE.g., 48V, 60V, etc.;

2. setting controller I/O port at V_inThe input PWM frequency, e.g., 10 kHz;

3. different PWM duty ratios are set according to different rotating speeds, and the duty ratios are in direct proportion to the rotating speeds, as shown in FIG. 4.

When the pulse velocity measurement output port is used, the implementation steps are as follows:

1. power selection switch S₁Connecting a digital power supply VCC, such as 3.3V, 5V and the like;

2. setting controller I/O port at V_inThe duty cycle of the input square wave, typically 50%, is shown in fig. 5;

3. according to different rotating speeds, different square wave frequencies are set, and the square wave frequencies are in direct proportion to the rotating speeds.

When the communication bus speed measurement output port is used, the implementation steps are as follows:

1. power selection switch S₁Connecting a digital power supply VCC, such as 3.3V, 5V and the like;

2. selecting a communication bus type, such as a LIN bus;

it should be noted that the communication bus generally has a certain data communication format, such as common RS-485 and USB communication buses; the contents of the predetermined communication protocol include a communication rate, a start frame (STA), a data frame (D0, D1 … … Dn), a check bit (CKC), a termination flag (SOF), etc., as shown in fig. 5.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it will be understood by those skilled in the art that various changes and modifications may be made herein without departing from the spirit and scope of the invention as defined in the appended claims.