Brushless motor high-speed optimization control circuit based on modulator coded disc

Abstract

The invention relates to the technical field of brushless motor control, in particular to a high-speed optimization control circuit of a brushless motor based on a modulator coded disc, which comprises a DSP (Digital Signal Processor), a motor driving circuit and a differential conversion circuit, and is characterized in that a Hall sensor detects a rotating speed differential signal of the brushless motor on line; the differential conversion circuit converts a differential signal of the Hall sensor into a single-ended signal for the processor to identify and collect; a speed feedback loop of the DSP processor calculates the rotating speed of the motor in real time; a speed feedback loop of the DSP adopts an orthogonal coding interface, and the rotating speed of the motor is calculated in real time through configuration and conversion; a speed control loop of the DSP adopts PWM (Pulse Width Modulation) output, integral separation PID (Proportion Integration Differentiation) control and threshold adjustment to realize motor rotating speed control; the invention provides a control system which is fast in response, high in precision, small in size and low in cost, a digital control technology is used for optimally controlling the high-speed coded disc motor, and the rotating speed of the motor can be flexibly adjusted by setting parameters according to use requirements or load changes.

Description

Technical Field

[0001] The invention belongs to the technical field of brushless motor control of embedded systems, and in particular relates to a high-speed optimization control circuit of a brushless motor based on a modulator code disk. Background Art

[0002] Laser beam-riding guidance is a missile guidance method. Its working principle is: a laser transmitter emits a coded laser beam, and the missile flies along the laser beam after launch. The missile receives the laser signal, and adjusts the flight attitude through the control system after solving it, so as to accurately hit the target. With the large-scale application of portable weapons and unmanned aerial vehicle weapons, the miniaturization of laser beam-riding guidance products is a future development trend.

[0003] The modulator code disk is the core component of the modulator of the laser beam riding guidance device. By improving the overall performance of the modulator under different application conditions, it can meet the missile flight control requirements in complex environments.

[0004] When laser beam encoding, the motor (modulation code disk) speed is required to be stable at 100±1r / s, and the startup time is within 2s. However, at present, due to the constraints of motor control technology conditions, the existing control system has the following main shortcomings: 1. Under the condition of meeting the coding accuracy requirements, the startup time is too long and is not suitable for high-speed combat requirements; 2. The size of the control circuit built with processor + transistor is slightly large, and the future development space is limited; 3. Thick film circuit, the startup time is 2s~3s, the entire control circuit is relatively complex, not easy to update, and the cost is high. Summary of the invention

[0005] In view of the above situation, in order to solve the problems existing in the prior art, the present invention provides a high-speed optimization control circuit of a brushless motor based on a modulator code disk, which can start quickly, has high precision, simple circuit structure, is easy to maintain, miniaturized, and has low cost.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A high-speed optimization control circuit for a brushless motor based on a modulator code disk comprises a brushless motor and a motor control system. The motor control system comprises a DSP processor, a motor drive circuit and a differential conversion circuit.

[0008] The speed control loop of the DSP processor controls the speed of the brushless motor through the motor drive circuit.

[0009] The differential conversion circuit is used to convert the differential signal of the Hall sensor into a single-ended signal for identification and collection by the processor.

[0010] The Hall sensor is used for online detection of the rotation speed differential signal of the brushless motor.

[0011] The speed feedback loop of the DSP processor is used to calculate the rotation speed of the brushless motor in real time.

[0012] Furthermore, the speed control loop of the DSP processor adopts PWM output, and the speed of the brushless motor is controlled by adopting optimized integral separation PID control and adjusting the threshold.

[0013] Furthermore, the speed feedback loop of the DSP processor adopts an orthogonal encoding interface, and through configuration and conversion, the current speed of the brushless motor is calculated in real time.

[0014] Furthermore, the processor (DSP) periodically reads the Hall orthogonal signal value, converts the motor speed, calls the integral separation PID algorithm, calculates the required PWM duty cycle, and controls the motor to accelerate or decelerate.

[0015] Preferably, the DSP processor includes an ADP32F035 chip, which is an embedded chip; the peripheral circuit of the DSP processor chip includes a crystal oscillator circuit, which is used to provide a reliable clock source (or operating frequency) for the DSP processor chip, and the crystal oscillator circuit includes a crystal oscillator and two resonant capacitors connected in parallel with each other, one end of the two resonant capacitors is connected to 0V, and the other ends of the two resonant capacitors are respectively connected to the two ends of the crystal oscillator and connected to the corresponding pins of the DSP processor chip.

[0016] Preferably, the motor drive circuit includes an MS8829 chip, which is a drive chip dedicated to brushless motors; the peripheral circuit of the drive chip includes a voltage divider resistor, a reference resistor, a storage capacitor, two filter capacitors, an output capacitor and a protection resistor;

[0017] One end of the voltage divider resistor is connected to 0V, and the other end is connected to the corresponding pin of the driver chip and the reference resistor to lower the output voltage of the Hall sensor;

[0018] One end of the reference resistor is connected to the voltage divider resistor, and the other end is connected to the corresponding pin of the driver chip, so as to provide a reference voltage for the driver chip;

[0019] The two ends of the energy storage capacitor are respectively connected to two corresponding pins of the driver chip to store energy for the charge pump of the driver chip;

[0020] Two filter capacitors connected in parallel are connected to 0V at one end and the power supply at the other end, and are connected to the corresponding pins of the driver chip to filter the power supply of the driver chip;

[0021] One end of the output capacitor is connected to the corresponding pin of the driver chip, and the other end is connected to the corresponding pin of the driver chip, which is the output of the charge pump of the driver chip;

[0022] The two ends of the protection resistor are respectively connected to the corresponding pins of the driver chip to provide an overcurrent protection circuit for the driver chip.

[0023] The corresponding pins of the driver chip are connected to the corresponding pins of the DSP processor chip. The DSP processor chip outputs a PWM signal to the driver chip. The three corresponding pins of the driver chip output U, V, and W three-phase drive power supplies to control the rotation of the brushless motor.

[0024] The corresponding pins of the driver chip are connected to the corresponding pins of the DSP processor chip, and the DSP processor chip controls the start and stop of the brushless motor through the pins;

[0025] The corresponding pins of the driver chip are connected to the corresponding pins of the DSP processor chip, and the DSP processor chip controls the forward and reverse rotation of the brushless motor through the pins.

[0026] Preferably, the differential conversion circuit includes an AM26LV32 chip, which is a differential to single-ended signal conversion chip. The peripheral circuit of the conversion chip includes two differential resistors and, the two differential resistors are respectively connected to the corresponding pins of the conversion chip to provide matching resistance for the differential Hall signal;

[0027] The corresponding pins of the conversion chip are respectively connected to the corresponding pins of the DSP processor chip, so as to provide an orthogonal signal to the DSP processor chip for the DSP processor chip to calculate the rotation speed of the brushless motor.

[0028] The present invention uses new digital control technology to optimize the control of the modulator code disk brushless motor. That is, a more streamlined hardware circuit with domestic DSP microprocessor and driver chip as the core is built, and an improved PID software control algorithm is used to flexibly control the stable rotation of the modulator code disk brushless motor.

[0029] The present invention also includes other components that enable it to be used normally, which are all conventional means in the field. In addition, devices or components not limited in the present invention, such as: ADP32F035 chip, MS8829 chip, AM26LV32 chip, etc., all adopt the existing technology in the field.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1) By optimizing and improving the brushless motor control circuit, the complexity of the control circuit is effectively simplified. It is mainly composed of a processor + driver chip + differential to single-ended chip, which greatly reduces the product size and creates conditions for the miniaturization of future laser beam-riding guidance products.

[0032] 2) By using the optimized integral separation PID algorithm and accurately adjusting the system sampling period, parameter thresholds, initial settings, etc., the system startup time can be reduced to less than 1s and the stable speed can be 100±0.5r / s, which is better than the technical requirements of 2s startup time and 100±1r / s speed.

[0033] 3) According to usage requirements or load changes, the motor rotation speed can be flexibly adjusted by setting parameters, which is convenient for later transplantation and promotion, helps save costs and improve product adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the circuit diagram of ADP32F035 chip in the embodiment.

[0035] Figure 2 It is the circuit diagram of MS8829 chip in the embodiment.

[0036] Figure 3 It is the circuit diagram of AM26LV32 chip in the embodiment.

[0037] Figure 4 It is a three-dimensional diagram of the PCBA circuit board of the control circuit in the embodiment.

[0038] Figure 5 It is a flowchart of the integral separation PID control method in the embodiment.

[0039] Figure 6 It is a flow chart of the DSP processor control system in the embodiment. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments.

[0041] Example

[0042] like Figure 1-4 As shown, a high-speed optimization control circuit of a brushless motor based on a modulator code disk includes a brushless motor and a motor control system. The motor control system includes a DSP processor, a motor drive circuit and a differential conversion circuit. The entire system is arranged on a PCBA circuit board with a circuit board as a carrier.

[0043] The speed control loop of the DSP processor controls the speed of the brushless motor through the motor drive circuit.

[0044] The differential conversion circuit is used to convert the differential signal of the Hall sensor into a single-ended signal for identification and collection by the processor.

[0045] The Hall sensor is used for online detection of the rotation speed differential signal of the brushless motor.

[0046] The speed feedback loop of the DSP processor is used to calculate the rotation speed of the brushless motor in real time.

[0047] The speed control loop of the DSP processor adopts PWM output, and the speed control of the brushless motor is realized by adopting optimized integral separation PID control and adjusting the threshold.

[0048] The speed feedback loop of the DSP processor adopts an orthogonal encoding interface, and through configuration and conversion, the current speed of the brushless motor is calculated in real time.

[0049] The processor (DSP) periodically reads the Hall orthogonal signal value, converts it into the motor speed, calls the integral separation PID algorithm, calculates the required PWM duty cycle, and controls the motor to accelerate or decelerate.

[0050] like Figure 5 As shown, in the integral separation PID control algorithm of the present invention, the purpose of the integral link I is to eliminate static error and increase stability. During the startup of the control system or when the speed is greatly increased or decreased by external factors, a large overshoot will be caused. The improved PID adopts an integral separation method. When the current speed of the motor is greatly different from the target speed, the integral link is removed and the PD algorithm is used. When the motor speed reaches a certain threshold, the PID algorithm is used again.

[0051] The specific implementation steps are as follows:

[0052] 1) According to the actual situation, set the target speed N0 and the threshold Δ0;

[0053] 2) When |Δ|>Δ0, that is, the current motor speed is significantly different from the target speed, the PD algorithm is used to reduce overshoot and the system has a faster response.

[0054] 3) When |Δ|≤Δ0, that is, the difference between the current motor speed and the target speed is small, the PID algorithm can be used to ensure the control accuracy of the system.

[0055] The DSP processor includes an ADP32F035 chip, which is an embedded chip; the peripheral circuit of the DSP processor chip U1 includes a crystal oscillator circuit, which is used to provide a reliable clock source (or operating frequency) for the DSP processor chip. The crystal oscillator circuit includes a crystal oscillator X1 and two resonant capacitors C8 and C9 connected in parallel with each other, one end of the two resonant capacitors is connected to 0V, and the other ends of the two resonant capacitors are respectively connected to the two ends of the crystal oscillator X1, and connected to the corresponding pins 40 and 41 of the DSP processor chip U1.

[0056] According to the characteristics of DSP processor ADP32F035, the embedded circuit uses a 10M crystal oscillator, a resistor-capacitor circuit to build a reset circuit, and the program debugging interface uses Jtag mode.

[0057] The motor drive circuit includes an MS8829 chip, which is a drive chip dedicated to brushless motors; the peripheral circuit of the drive chip U4 includes a voltage divider resistor R18, a reference resistor R19, a storage capacitor C29, two filter capacitors C3 and C15, an output capacitor C30 and a protection resistor R2;

[0058] One end of the voltage divider resistor R18 is connected to 0V, and the other end is connected to the corresponding pins 1, 3, 5 of the driver chip U4 and the reference resistor R19 to pull down the output voltage of the Hall sensor;

[0059] One end of the reference resistor R19 is connected to the voltage divider resistor R18, and the other end is connected to the corresponding pin 8 of the driver chip U4, so as to provide a reference voltage for the driver chip U4;

[0060] The two ends of the energy storage capacitor C29 are respectively connected to the two corresponding pins 9 and 10 of the driver chip U4, and are used to store energy for the charge pump of the driver chip U4;

[0061] Two filter capacitors C3 and C15 connected in parallel are connected to 0V at one end and 26V power supply at the other end, and are connected to corresponding pins 11 and 12 of the driver chip U4 to filter the power supply of the driver chip U4;

[0062] One end of the output capacitor C30 is connected to the corresponding pins 11 and 12 of the driver chip U4, and the other end is connected to the corresponding pin 13 of the driver chip U4, which is the output of the charge pump of the driver chip U4;

[0063] The two ends of the protection resistor R2 are respectively connected to the corresponding pins 17 and 18 of the driving chip U4 to provide an overcurrent protection circuit for the driving chip U4.

[0064] Pin 23 of the driver chip U4 is connected to the corresponding pin 31 of the DSP processor chip U1. The DSP processor chip U1 outputs a PWM signal to the driver chip U4. The three pins 14, 15, and 16 of the driver chip U4 output U, V, and W three-phase drive power supplies to control the rotation of the brushless motor.

[0065] Pin 19 of the driver chip U4 is connected to the corresponding pin 34 of the DSP processor chip U1, and the DSP processor chip U1 controls the start and stop of the brushless motor through this pin;

[0066] The pin 21 of the driving chip U4 is connected to the corresponding pin 33 of the DSP processor chip U1, and the DSP processor chip U1 controls the forward and reverse rotation of the brushless motor through the pin.

[0067] The differential conversion circuit includes an AM26LV32 chip, which is a differential to single-ended signal conversion chip. The peripheral circuit of the conversion chip U2 includes two differential resistors R3 and R4. The two differential resistors R3 and R4 are respectively connected to the corresponding pins 1, 2 and 6, 7 of the conversion chip U2 to provide matching resistance for the differential Hall signal;

[0068] The corresponding pins 3 and 5 of the conversion chip U2 are respectively connected to the corresponding pins 62 and 63 of the DSP processor chip U1, so as to provide an orthogonal signal to the DSP processor chip U1 for the DSP processor chip U1 to calculate the rotation speed of the brushless motor.

[0069] like Figure 6 As shown, the DSP processor control system process is as follows:

[0070] After the system is powered on, the motor is initialized to start at full speed to shorten the startup time; according to the output of the Hall sensor 512 line, the sampling closed-loop period is set to 204.22 microseconds, with a smaller sampling period error to ensure the integrity of the acquired orthogonal encoding; the integral separation PID is used to reduce the damping at startup and speed up the startup. At the same time, when the predetermined speed is about to be reached, I is increased to ensure the stability of the motor speed; the threshold Δ0 is set to match the interruption period (204.22ns) to avoid the situation where the overshoot cannot be called back.

[0071] The embedded reading and writing software program is as follows:

[0072] interrupt void Timer0_INT(void)

[0073] {

[0074] DINT; / / turn off the general interrupt

[0075] StopCpuTimer0(); / / Stop the timer

[0076] CpuTimer0Regs.TCR.bit.TIF=1; / / Clear interrupt flag

[0077] CNT0=EvbRegs.T4CNT; / / .T2CNT;

[0078] EvbRegs.T4CNT = 0x0000;

[0079] PieCtrlRegs.PIEACK.all|=0x0001; / / respond to interrupt

[0080] ReloadCpuTimer0(); / / Timer reload

[0081] StartCpuTimer0(); / / Start the timer

[0082] Fre_time = 65535 - CNT0;

[0083] pidcontrol(Fre_time, 210); / /

[0084] EINT; / / Enable the total interrupt

[0085] }

[0086] void pidcontrol(Uint16 u, int y)

[0087] {

[0088] ek = (int)(u - y);

[0089] if ((ek > 5) || (ek < -5)) kk = 0;

[0090] else kk = 1;

[0091] duk = kp * (ek - ek1) + kk * ki * ek + SUM;

[0092] SUM = duk;

[0093] pwm = (Uint16)duk;

[0094] if (pwm < 50)

[0095] {

[0096] pwm = 50;

[0097] }

[0098] if (pwm > 3300)

[0099] {

[0100] pwm = 3300;

[0101] }

[0102] EvaRegs.CMPR3 = pwm;

[0103] ek2 = ek1;

[0104] ek1 = ek;

[0105] }

[0106] Through the appropriate logic of the software program, the control circuit can complete the start of the motor in 1s and stabilize the speed at 100±0.5r / s. The circuit structure is streamlined and the size is reduced to 70% of the original size ( Figure 6 The entire size of the PCBA circuit board is the original circuit size, and the blank space at the top is for space saving).

[0107] From the above analysis, it can be seen that replacing complex circuits with streamlined control circuits can reduce the overall volume and weight of the modulator, achieve miniaturization, modularization and lightweight of the product, and better guarantee the overall performance of the components, while saving costs and providing conditions for the development of future weapons.

[0108] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to ordinary technicians in this technical field. Any technical deformation made within the spirit and principles of the present invention falls within the protection scope of the present invention.

Claims

1. A high-speed optimized control circuit for a brushless motor based on a modulator code disk, comprising a brushless motor and a motor control system, characterized in that: The motor control system includes a DSP processor, a motor drive circuit and a differential conversion circuit. The speed control loop of the DSP processor realizes speed control of the brushless motor through the motor drive circuit; the differential conversion circuit is used to convert the differential signal of the Hall sensor into a single-ended signal for processor identification and collection; the Hall sensor is used to detect the speed differential signal of the brushless motor online; the speed feedback loop of the DSP processor is used to calculate the speed of the brushless motor in real time.

2. According to claim 1, a high-speed optimization control circuit for a brushless motor based on a modulator code disk, characterized in that: The speed control loop of the DSP processor adopts PWM output, and the speed control of the brushless motor is realized by adopting optimized integral separation PID control and adjusting the threshold.

3. The high-speed optimization control circuit of a brushless motor based on a modulator code disk according to claim 1, characterized in that: The speed feedback loop of the DSP processor adopts an orthogonal encoding interface, and through configuration and conversion, the current speed of the brushless motor is calculated in real time.

4. The high-speed optimization control circuit of a brushless motor based on a modulator code disk according to claim 1, characterized in that: The DSP processor adopts ADP32F035 chip.

5. The high-speed optimization control circuit of a brushless motor based on a modulator code disk according to claim 1, characterized in that: The motor driving circuit includes an MS8829 chip.

6. The high-speed optimization control circuit of a brushless motor based on a modulator code disk according to claim 1, characterized in that: The differential conversion circuit includes an AM26LV32 chip.

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