阅读说明：本技术 一种无刷直流电机pi控制系统 (PI control system of brushless direct current motor ) 是由 刘运录 于 2019-11-24 设计创作，主要内容包括：本发明公开了一种无刷直流电机PI控制系统,包括PI控制器、转速控制模块、电机驱动电路和无刷直流电机,所述PI控制器与转速控制模块相连接,转速控制模块与电机驱动电路相连接,所述无刷直流电机的输出端电性连接有霍尔传感器,所述霍尔传感器的输出端电性连接有减法器,该减法器的输出端连接有CPLD平台。本发明能够使用二分法的减法算法,利用高速运行的减法器来实现除法的功能,从而得到转速信息,作差来得到转速误差信息,极大提高了除法器的效率,有利于该无刷直流电机PI控制系统的快速运行。(The invention discloses a PI control system of a brushless direct current motor, which comprises a PI controller, a rotating speed control module, a motor driving circuit and the brushless direct current motor, wherein the PI controller is connected with the rotating speed control module, the rotating speed control module is connected with the motor driving circuit, the output end of the brushless direct current motor is electrically connected with a Hall sensor, the output end of the Hall sensor is electrically connected with a subtracter, and the output end of the subtracter is connected with a CPLD platform. The invention can use the subtraction algorithm of the dichotomy and realize the function of division by using the subtracter which runs at high speed, thereby obtaining the rotating speed information and obtaining the rotating speed error information by making a difference, greatly improving the efficiency of the divider and being beneficial to the quick running of the PI control system of the brushless direct current motor.)

1. The utility model provides a brushless DC motor PI control system, includes PI controller (1), rotational speed control module (2), motor drive circuit (3) and brushless DC motor (4), its characterized in that: the PI controller (1) is connected with the rotating speed control module (2), the rotating speed control module (2) is connected with the motor driving circuit (3), and the output end of the motor driving circuit (3) is electrically connected with the brushless direct current motor (4); the output end of the brushless direct current motor (4) is electrically connected with a Hall sensor (5), the output end of the Hall sensor (5) is electrically connected with a subtracter (6), and the output end of the subtracter (6) is connected with a CPLD platform (8); the CPLD platform (8) comprises a frequency division module (81), and the output end of the frequency division module (81) is electrically connected with the PI controller (1) and the rotating speed control module (2) respectively.

2. The PI control system of claim 1, wherein: the output end of the Hall sensor (5) is further connected with an integrator (7), the integrator (7) is connected with the PI controller (1), and the integrator (7) is used for enabling output of the PI controller (1) to be in smooth transition when the control system returns to normal.

3. The PI control system of claim 1, wherein: the module updating rate of the rotating speed control module (2) is 10kHz, and the rotating speed control module (2) is used for stabilizing the running rotating speed of the brushless direct current motor (4) and switching into a PI rotating speed closed loop.

4. The PI control system of claim 1, wherein: the subtracter (6) is used for controlling a system rotating speed conversion link to realize a division function so as to obtain the rotating speed information of the brushless direct current motor (4).

5. The PI control system of claim 1, wherein: and the CPLD platform (8) is used for receiving Hall position signals of the brushless direct current motor (4) and distributing PWM signals provided by the PI controller (1) into control signals of the brushless direct current motor (4).

Technical Field

The invention relates to the technical field of brushless direct current motor control, in particular to a PI control system for completing a brushless direct current motor by using software, and specifically relates to a PI control system for the brushless direct current motor.

Background

The brushless direct current motor has the advantages of being reliable in operation, high in working efficiency, convenient to maintain and the like, and is widely applied to the field of servo control.

At present, in a control system of a brushless direct current motor, a proportion and integral operation circuit is usually built by using a hardware circuit, and in a software part, a speed loop and a current loop are usually completed by using a DSP (digital signal processor), so that the closed loop of the control system is completed, and a separate CPLD (complex programmable logic device) is not used for realizing control; meanwhile, the DSP is adopted to complete the updating of the rotating speed under the condition of a faster rotating speed in a speed loop, so that the efficiency of the divider is slower, and the control of the brushless direct current motor is not favorable for fast operation.

Disclosure of Invention

The invention aims to provide a brushless direct current motor PI control system to solve the problem that the efficiency of a divider is low because the updating of the rotating speed cannot be completed in time under the condition of high rotating speed in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the system comprises a PI controller, a rotating speed control module, a motor driving circuit and a brushless direct current motor, wherein the PI controller is connected with the rotating speed control module, the rotating speed control module is connected with the motor driving circuit, and the output end of the motor driving circuit is electrically connected with the brushless direct current motor; the output end of the brushless direct current motor is electrically connected with a Hall sensor, the output end of the Hall sensor is electrically connected with a subtracter, and the output end of the subtracter is connected with a CPLD platform; the CPLD platform comprises a frequency division module, and the output end of the frequency division module is electrically connected with the PI controller and the rotating speed control module respectively.

Preferably, the output end of the hall sensor is further connected with an integrator, the integrator is connected with the PI controller, and the integrator is used for enabling the output of the PI controller to be in smooth transition when the control system returns to normal.

Preferably, the module update rate of the rotating speed control module is 10kHz, and the rotating speed control module is used for stabilizing the operating rotating speed of the brushless direct current motor and switching into a PI rotating speed closed loop.

Preferably, the subtracter is used for controlling a system rotation speed conversion link to realize a division function so as to obtain the brushless direct current motor rotation speed information.

Preferably, the CPLD platform is configured to receive a hall position signal of the brushless dc motor and distribute a PWM signal provided by the PI controller to a control signal of the brushless dc motor.

Compared with the prior art, the invention has the beneficial effects that:

1. the subtractor and the rotating speed conversion link added in the invention can use a subtraction algorithm of dichotomy, and the subtractor running at high speed is used for realizing the function of division, namely, the divisor is multiplied by 2-N to be used as the divisor for subtraction, so that the rotating speed information is obtained, and the rotating speed error information is obtained by making a difference, thereby greatly improving the efficiency of the divider and being beneficial to the rapid running of the PI control system of the brushless direct current motor.

Drawings

FIG. 1 is a block diagram of a brushless DC motor PI control implementation of the invention based on a CPLD platform;

fig. 2 is a control block diagram of the frequency division module of the brushless direct current motor based on the CPLD platform.

In the figure: the device comprises a PI controller 1, a rotating speed control module 2, a motor driving circuit 3, a brushless direct current motor 4, a Hall sensor 5, a subtractor 6, an integrator 7, a CPLD platform 8 and a frequency division module 81.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, the present invention provides a technical solution: the system comprises a PI controller 1, a rotating speed control module 2, a motor driving circuit 3 and a brushless direct current motor 4, wherein the PI controller 1 is connected with the rotating speed control module 2, the rotating speed control module 2 is connected with the motor driving circuit 3, and the output end of the motor driving circuit 3 is electrically connected with the brushless direct current motor 4; the module updating rate of the rotating speed control module 2 is 10kHz, and the rotating speed control module 2 is used for stabilizing the running rotating speed of the brushless direct current motor 4 and switching into a PI rotating speed closed loop; the output end of the brushless direct current motor 4 is electrically connected with a Hall sensor 5, the Hall sensor 5 collects Hall information of the brushless direct current motor 4, the output end of the Hall sensor 5 is electrically connected with a subtracter 6, and the subtracter 6 is used for controlling a system rotation speed conversion link to realize a division function so as to obtain rotation speed information of the brushless direct current motor 4; the subtractor 6 adopts any one of SN74LS92 type, SOP-16 type and CD74AC283E type subtracters, the subtractor 6 can be used for a divider carried by a control system CPLD platform, the divider adopts a conventional divider to operate a PI control system, the divider multiplies 2-N as the divisor to start calculation, if the dividend is greater than the divisor, the quotient is added with 1, the dividend subtracts the divisor to obtain a new dividend, the dividend is known to be smaller than the divisor, in the calculation, the divider operates with a flag set at 1, the division rule is cleared by 0 so as to enable the divider module to clear an enable signal, the subtractor 6 adopts a subtraction algorithm of a dichotomy to multiply the divisor by 2-N as the divisor to start calculation, and the efficiency of the divider is greatly improved, wherein the divider adopts any one of AD633JN type and HA9P2556-9 type; the output end of the subtracter 6 is connected with a CPLD platform 8; the CPLD platform 8 comprises a frequency division module 81, and the output end of the frequency division module 81 is electrically connected with the PI controller 1 and the rotating speed control module 2 respectively; the CPLD platform 8 is used for receiving Hall position signals of the brushless direct current motor 4 and distributing PWM signals provided by the PI controller 1 into control signals of the brushless direct current motor 4; the output end of the Hall sensor 5 is also connected with an integrator 7, the integrator 7 is connected with the PI controller 1, and the integrator 7 is used for enabling the output of the PI controller 1 to be in smooth transition when the control system returns to normal.

The integrator 7 is any one of an LF357 type integrator, a PRVAR10 type integrator and a QA500 type integrator; when the system is in fault and the PI controller 1 is not used for PI control, the output of the integrator 7 is back-calculated by using the output of the rotating speed control module 2 and the PI structure, so that when the system is recovered to be normal and the PI controller 1 is adopted, the output of the PI controller 1 can be in smooth transition; the PI calculation part realizes the calculation of PI output and carries out the amplitude limiting of the output of the PI controller 1; the integrator 7 includes an integrator circuit, which is a conversion circuit for converting an acceleration signal into a velocity and a displacement by the signal conditioner.

The working principle is as follows: the CPLD platform 8 is used for receiving Hall position signals of the brushless direct current motor 4 and PWM signals generated by the PI controller 1, distributing the PWM signals generated by the PI controller 1 into control signals of the brushless direct current motor 4, directly converting each PWM signal output by the CPLD chip in the CPLD platform 8 into a driving signal and sending the driving signal to the motor driving circuit 3, and controlling the operation of the brushless direct current motor 4 through the motor driving circuit 3.

The updating rate of the rotating speed control module 2 is 10kHz, the switching frequency is matched with 10kHz, when the brushless direct current motor 4 in the control system is at low speed, the CPLD chip of the CPLD platform 8 is adopted to start rotation control, and when the brushless direct current motor 4 in the control system reaches the stable running rotating speed, a PI rotating speed closed loop is switched in; the PI controller 1 adopts any one of N5-1-5 type, C5-E-CANopen type and CL4-E-1-12 type controllers; the brushless dc motor 4 is any one of a DMK16-DEC1625 type and a D4BLD60-24-25S-RC type motor.

The subtractor 6 and the rotating speed conversion link added in the invention can use a dichotomy subtraction algorithm, and the subtractor 6 running at high speed is used for realizing the function of division, namely, the divisor is multiplied by 2-N to be used as the divisor for subtraction operation, so that the rotating speed information is obtained, and the rotating speed error information is obtained by difference, thereby greatly improving the efficiency of the divider, being beneficial to the rapid running of the PI control system of the brushless direct current motor, and solving the problem that the efficiency of the divider is slower because the rotating speed cannot be timely updated under the condition of higher rotating speed in the existing control system of the brushless direct current motor.

The frequency division module 81 of the CPLD platform 8 adopts any one of PA-280JBL type and HY-T3 type frequency dividers; the CPLD adopts programming technologies such as CMOS EPROM, EEPROM, flash memory, SRAM and the like, thereby forming a programmable logic device with high density, high speed and low power consumption; the CPLD is mainly composed of a logic block, a programmable interconnection channel and an I/O block; the CPLD includes EPM7128S devices and XCR3064XL devices.

In the added rotation speed conversion link, the subtractor 6 running at high speed is used for realizing the division function of the divider, so that rotation speed information is obtained, and the difference is made to obtain rotation speed error information; the invention improves the measuring speed of the rotating speed, the rotating speed is updated in one Hall period of the Hall sensor 5, and meanwhile, the filtering is kept, and the measuring speed is improved by six times; the improvement of the speed measurement rate is beneficial to the closed-loop control of the speed control; the Hall sensor 5 adopts any one of JS-HA18D-SE type, JS-169 type and YS96B type sensors, information obtained by the Hall sensor 5 is converted into rotating speed information, the formula is spced =100M/spced _ reg, division comparison is realized in a CPLD to occupy resources, a rotating speed conversion link is added, and a subtracter 6 which runs at a high speed is used for realizing the function of division, so that the rotating speed information is obtained, and the rotating speed error information is obtained by subtracting.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.