CN203708164U - Chopper variable-value control device - Google Patents

Abstract

The utility model discloses a chopper variable value control device for controlling the constant-speed rotation of a motor, which comprises a set speed input part for inputting the motor, a voltage source part for providing voltage for a motor driver of the motor, and used for adjusting The voltage adjustment part, the acquisition part for collecting the actual speed of the motor, the display part for real-time display of the actual speed of the motor, the storage part for storing the value of the set speed and the value of the actual speed, and the input part, the voltage source part, the The control unit connected to the adjustment unit, the acquisition unit, the display unit and the storage unit, the acquisition unit feeds back the actual speed of the motor to the control unit, and the control unit adjusts the voltage of the motor driver based on the set speed and the actual speed control voltage adder, thereby stabilizing the motor speed. The variable value control device of the chopper in the utility model has the advantages of simple structure, low cost, high speed regulating precision and good speed stabilizing effect.

Description

chopper variable value control device

technical field

The utility model relates to a chopper, in particular to a variable value control device for a chopper used to control a motor to rotate at a constant speed.

Background technique

With the rapid development of microelectronics technology, power electronics technology and other technologies, brushless DC motors using the principle of electronic commutation have been greatly developed. However, many small brushless DC motors often require more precise speed control, especially in high-speed applications, where the requirements for signal feedback and processing speed are more stringent. In this case, simply giving the theoretical voltage to control the motor according to the required speed cannot meet the requirements, and the characteristics of the motor cannot be fully utilized. Therefore, a complete system is needed to control the rotation of the motor, that is, chopping device.

In the prior art, the realization of the constant speed rotation of the motor is mainly achieved through frequency conversion speed regulation and thyristor phase shifting speed regulation. Frequency conversion speed regulation is based on the proportional relationship between the motor speed and the frequency of the working power supply, and uses the on-off function of the power semiconductor device to change the frequency of the motor's working power supply, thereby achieving the purpose of changing the motor speed. Thyristor phase-shift speed regulation is achieved by changing the conduction angle of the thyristor to change the motor terminal voltage to achieve speed regulation. When the conduction angle is less than 180°, the thyristor is in a non-full conduction state. Smaller, the smaller the voltage, the lower the speed.

However, in the above scheme, the SCR speed control will generate a large number of harmonics, and the high-frequency interference cannot be eliminated, while the frequency conversion speed control has no high-frequency interference, but the cost is expensive, which greatly increases the cost of production research. Therefore, the prior art lacks a chopper variable value control device for controlling the motor to rotate at a constant speed.

Utility model content

In order to solve the above problems, the purpose of this utility model is to provide a chopper variable value control device for controlling the motor to rotate at a constant speed.

In order to achieve the above purpose, the utility model provides a chopper variable value control device for controlling the motor to rotate at a constant speed, which has such characteristics: it includes: an input part for inputting the set speed of the motor, a voltage source part , used to provide voltage for the motor driver of the motor, the adjustment part, including a voltage adder composed of 2 DAC outputs, used to adjust the voltage, the acquisition part, including the photoelectric encoder and the acquisition photoelectric encoder driven by the motor to rotate at the same speed The pulse counter of the number of output pulses, the display part is used to display the value of the actual speed of the motor in real time, the storage part is used to store the value of the set speed and the value of the actual speed, and the control part is respectively connected with the input part and the voltage source The control unit, the adjustment unit, the acquisition unit, the display unit and the storage unit are connected, and the display unit is controlled to display the actual speed of the motor based on the number of output pulses, and the voltage adder is controlled to adjust the voltage of the motor driver based on the set speed and the actual speed.

In the variable value control device of the chopper provided by the utility model, it may also have such a feature: wherein, the control part includes a single-chip microcomputer for controlling the voltage adder.

In the variable value control device of the chopper provided by the utility model, it may also have such a feature: wherein, the display unit is a host computer for displaying the actual rotation speed of the motor and the change of the digital input quantity of the voltage adder.

In the variable value control device of the chopper provided by the utility model, it may also have such a feature: wherein, the display part is an 8-segment LED digital tube.

Function and effect of utility model

According to the chopper variable value control device for controlling the constant-speed rotation of the motor involved in the utility model, it includes an input part for inputting the set speed of the motor, and a voltage source part for providing voltage to the motor driver of the motor, for The regulating part for adjusting the voltage, the collecting part for collecting the actual rotational speed of the motor, and the control part respectively connected with the input part, the voltage source part, the regulating part, and the collecting part, the collecting part feeds back the actual rotating speed of the motor to the control part, and the control part Based on the set speed and the actual speed, the control voltage adder adjusts the voltage of the motor driver, thereby stabilizing the speed of the motor. The variable value control device of the chopper in the utility model has the advantages of simple structure, low cost, high speed regulating precision and good speed stabilizing effect.

Description of drawings

Fig. 1 is the block diagram of chopper variable value control device in the embodiment of the present utility model; And

Fig. 2 is a structural block diagram of a chopper variable value control device in an embodiment of the present invention.

In the figure, 100. chopper variable value control device, 1. input part, 2. voltage source part, 3. regulation part, 4. acquisition part, 5. display part, 6. storage part, 7. control part, 8 .Motor, 9. Motor driver, 10. Wheel set, 11. Keyboard, 12. Base, 31. Voltage adder, 41. Photoelectric encoder, 42. Pulse counter, 51. PC, 52. LED digital tube, 71. Microcontroller.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the utility model easy to understand, the utility model will be described in detail below in conjunction with the embodiments and accompanying drawings.

Example

Fig. 1 is a block diagram of a chopper variable value control device in an embodiment of the present invention.

As shown in Figure 1, the chopper variable value control device 100 in this embodiment includes: an input unit 1, a voltage source unit 2, an adjustment unit 3, an acquisition unit 4, a display unit 5, a storage unit 6, and a control unit 7 .

The adjustment part 3 includes a voltage adder 31 composed of 2 DAC outputs, the acquisition part 4 includes a photoelectric encoder 41 and a pulse counter 42, the control part 7 includes a single-chip microcomputer 71, and the display part 5 includes a PC 51 and an 8-segment LED digital tube 52 .

The control unit 7 is connected to the input unit 1, the voltage source unit 2, the adjustment unit 3, the acquisition unit 4, the display unit 5 and the storage unit 6 respectively, and the control unit controls the display unit 5 to display the actual rotational speed of the motor 8 based on the number of output pulses. The voltage adder 31 is controlled to adjust the voltage of the motor driver based on the set rotational speed and the actual rotational speed.

In this embodiment, a C8051F060 single-chip microcomputer is used as the core of the entire chopper variable value control device 100, which can control other peripheral devices while calculating and controlling the speed of the motor 8 in real time. The input unit 1 adopts a 4x4 keyboard 11 connected to the input port of the single-chip microcomputer 71 for inputting the set speed of the motor 8 . The voltage source part 2 provides voltage to the motor driver 9 of the motor 8, and the storage part 6 is used for storing the value of the set rotational speed and the numerical value of the actual rotational speed.

The motor driver 9 realizes the adjustment of the rotation speed of the motor 8 through an analog voltage, and the analog voltage can be obtained through DA conversion of the single-chip microcomputer 71 . Since the maximum output voltage obtained by each DA conversion of the single chip microcomputer 71 according to the reference voltage is only 2.43V, and the motor data sheet indicates that the motor needs at least a 4.5V speed regulation voltage when the motor rotates at the highest speed, the adjustment part 3 needs to use two circuits at the same time. The DAC output is used as an adding circuit to form a voltage adder 31 for controlling the voltage of the motor driver 9 .

The photoelectric encoder 41 driven by the motor 8 to rotate at the same speed and the pulse counter 42 to collect the output pulses of the photoelectric encoder 41 form a feedback unit. In order to effectively reduce the speed measurement error, the photoelectric encoder 41 with a resolution of 1000 is used to measure the speed of the motor 8 , to ensure real-time measurement of the rotational speed of the motor 8 for subsequent control. The display unit 5 includes a 4-digit 8-segment LED digital tube 52 and a PC 51, which can display the actual rotational speed of the motor 8 in real time.

Fig. 2 is a structural block diagram of a variable-value constant-speed control device for a chopper in an embodiment of the present invention.

As shown in Figure 2, the motor driver 9, the keyboard 11, the voltage adder 31, the pulse counter 42, the 8-segment LED digital tube 52, and the single-chip microcomputer 71 are all installed on the base 12, and the motor 8 and the photoelectric encoder 41 are arranged on the base 12 On the opposite side, the rotating shaft of motor 8 and photoelectric encoder 41 all runs through two pulleys of base 12 suit pulley group 10 respectively, is driven by synchronous belt between the pulleys, and PC 51 is connected with single-chip microcomputer 71.

When the chopper variable value control device 100 is powered on and initialized, the rated speed of the motor 8 will be given. If the rated speed needs to be changed, the set value of the motor 8 can be input at any time through the keyboard 11 connected to the input port of the single chip microcomputer 71 . When the rated speed or set speed is known, the single-chip microcomputer 71 will determine the driving voltage of the motor 8 according to the relationship between the speed of the motor 8 and the driving voltage. Since this process is realized by the DA conversion of the single-chip microcomputer 71, the output voltage is determined as follows: Determines the digital input to the DAC.

Since the photoelectric encoder 41 and the motor 8 are driven through the pulley set 10, and the diameters of the two pulleys that make up the pulley set are the same, after the system is powered on, the motor 8 drives the photoelectric encoder 41 to rotate at the same speed, and the photoelectric encoder 41 passes through the photoelectric encoder. Conversion converts the geometric displacement on the output shaft of the motor into a series of pulses for output. The code disc not shown in the figure rotates coaxially with the photoelectric encoder 41, and the code disc passes through the U-shaped groove of the optocoupler when it rotates. , so the speed calculated according to the output pulse of the optocoupler is 5 times of the speed of the motor 8, so as to achieve frequency multiplication, which can not only enable the optocoupler to output high-speed rotating pulses when the motor 8 is running at a low speed, but also ensure the output pulse The precision will not be reduced due to the high-speed rotation of the motor 8. The pulse counter 42 reads the output pulse quantity of the photoelectric encoder 41 in real time and feeds it back to the single-chip microcomputer 71. The single-chip microcomputer 71 processes the feedback pulse quantity at intervals of a unit time, thereby calculating the actual speed of the motor 8 and sending it to the 8-segment LED digital tube 52 shows that the actual rotational speed of the motor 8 and the digital input quantity change of the voltage adder 31 are displayed by the PC 51 through RS232 communication. At the same time, the single-chip microcomputer 71 adjusts the digital input value of the DAC to adjust the voltage of the motor driver 9 according to the difference between the actual rotation speed and the set rotation speed, thereby maintaining the rotation speed of the motor 8 in a stable state.

Function and effect of embodiment

The chopper variable value control device for controlling the constant-speed rotation of the motor provided according to this embodiment includes an input part for inputting the set speed of the motor, and a voltage source part for providing voltage to the motor driver of the motor for adjusting The voltage regulation part, the collection part that collects the actual speed of the motor, and the control part connected to the input part, the voltage source part, the regulation part, and the collection part respectively, the collection part feeds back the actual speed of the motor to the control part, and the control part The constant speed and actual speed control voltage adder adjusts the voltage of the motor driver, thereby stabilizing the speed of the motor. The variable value control device of the chopper in the utility model has the advantages of simple structure, low cost, high speed regulating precision and good speed stabilizing effect.

The photoelectric encoder and the motor are connected through a synchronous belt, and the two rotate at the same speed. The high-resolution photoelectric encoder is used to measure the speed, which effectively reduces the speed measurement error.

In this embodiment, a synchronous belt is used to realize the transmission between the motor and the photoelectric encoder, which effectively filters out part of the measurement error caused by the vibration of the motor, and provides a basic condition for further improving the measurement accuracy.

In this embodiment, a code disc that rotates coaxially with the photoelectric encoder is introduced to facilitate the multiplication of the motor speed while ensuring the system accuracy, and effectively reduce the error caused by severe vibration when the motor is running at high speed.

The input unit in this embodiment can arbitrarily set the rated rotational speed of the motor through the keyboard, realizing stepless speed regulation, and improving the deficiency that tap speed regulation can only be speed regulation by gear.

In this embodiment, the speed regulation process of the motor can be displayed on the host computer through RS232 communication, so that the user can observe the debugging process of the system more intuitively.

Of course, the variable-value constant-speed control device of the chopper involved in the present invention is not limited to the structure in this embodiment.

Claims (4)

1. A chopper variable value control device, used to control the constant speed rotation of the motor, is characterized in that, comprising: The input part is used to input the set speed of the motor; a voltage source section for providing voltage to a motor driver of the motor; The adjustment part includes a voltage adder composed of 2 DAC outputs for adjusting the voltage; The acquisition part includes a photoelectric encoder driven by the motor to rotate at the same speed and a pulse counter that collects the output pulse number of the photoelectric encoder; The display part is used to display the value of the actual rotational speed of the motor in real time; a storage unit for storing the value of the set rotational speed and the numerical value of the actual rotational speed; and The control unit is respectively connected to the input unit, the voltage source unit, the adjustment unit, the collection unit, the display unit and the storage unit, and controls the display unit to display The actual speed of the motor, based on the set speed and the actual speed, controls the voltage adder to adjust the voltage of the motor driver. the 2. The chopper variable value control device according to claim 1, characterized in that: Wherein, the control part includes a single-chip microcomputer controlling the voltage adder. the 3. The chopper variable value control device according to claim 1, characterized in that: Wherein, the display unit is a PC for displaying the actual rotation speed of the motor and the change of the digital input quantity of the voltage adder. the 4. The chopper variable value control device according to claim 1, characterized in that: Wherein, the display unit is an 8-segment LED digital tube. the