WO2021212520A1

WO2021212520A1 - Control method and apparatus for motor, device, and storage medium

Info

Publication number: WO2021212520A1
Application number: PCT/CN2020/086870
Authority: WO
Inventors: 李福�
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-28
Also published as: CN112956126A

Abstract

A control method and apparatus for a motor, a motor device, and a storage medium, wherein the motor does not have a position sensor. The method comprises: before a motor starts up, acquiring the current electric angular velocity of the motor by means of collecting the current voltage of the motor (S101); if the electric angular velocity is greater than or equal to a first preset threshold, then carrying out closed loop control on the motor by using the electric angular velocity as a feedback signal, so as to start up the motor, the first preset threshold being greater than zero (S102). The described solution increases the precision and reliability of motor control, thus improving the safety of the device.

Description

Motor control method, device, equipment and storage medium

Technical field

This application relates to the technical field of motor control, and in particular to a method, device, equipment, and storage medium for controlling a motor.

Background technique

Permanent magnet motors are widely used in unmanned aerial vehicles, electric vehicles, industrial inverters and other fields. At present, the control of the motor running status mainly includes two methods. One is the control based on the position sensor, and the control is given by the position sensor. The position signal and the calculated rotational speed signal control the motor; the other is the control without position sensor.

For a motor without a position sensor, the motor is in a high-speed and remote-rotation state when it is started, and the switch drag or high-frequency injection method used in general conditions will generate a huge current impact, which will cause damage to the motor equipment. It will take a certain amount of time to wait for the motor to stop and start again. For certain scenarios, serious accidents may occur. For example, the motor stopping of the drone will directly cause the drone to crash.

Therefore, how to achieve precise and reliable control of motors to improve the safety of UAVs and other equipment has become an urgent problem to be solved.

Summary of the invention

Based on this, the present application provides a motor control method, device, equipment, and storage medium, aiming to improve the accuracy and reliability of motor control, so as to improve the safety of the equipment.

In a first aspect, the present application provides a method for controlling a motor. The motor has no position sensor, including:

Before starting the motor, obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor;

If the electrical angular velocity is greater than or equal to a first preset threshold, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor; wherein the first preset threshold is greater than zero.

In the second aspect, the present application also provides a motor control device, the motor control device including a memory and a processor;

The memory is used to store a computer program;

The processor is configured to execute the computer program and, when executing the computer program, implement the following steps:

In the third aspect, the present application also provides a motor device, the motor device includes:

case;

A motor arranged in the housing;

As well as the above-mentioned motor control device, the motor control device is in communication connection with the motor.

In a fourth aspect, this application also provides a movable platform, which includes:

Body

A power system is provided in the body, the power system is used to provide power to the movable platform, and the power system includes a motor;

And one or more processors, configured to obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor before starting the motor; if the electrical angular velocity is greater than or equal to a first preset threshold, Then, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor; wherein, the first preset threshold is greater than zero.

In a fifth aspect, the present application also provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor realizes the control of the motor as described above. method.

The embodiments of the present application provide a motor control method, device, equipment, and storage medium. The motor has no position sensor. When the motor is started, the current electrical angular velocity of the motor is obtained by collecting the current voltage of the motor. It is greater than or equal to the first preset threshold, that is, when the motor is running fast, the current electrical angular velocity of the motor is used as a feedback signal to perform a closed-loop control of the motor to start the motor. There is no need to wait for the motor to stop and then restart the motor. It avoids motor deceleration, motor stalling, current impact, etc. caused by open-loop control or dragging by high-frequency injection method, so that the motor in high-speed rotation can be quickly controlled without stopping or current impact. Therefore, The accuracy and reliability of motor control are improved, which in turn improves the safety of the equipment.

It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the application.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following will briefly introduce the drawings used in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. Ordinary technicians can obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic block diagram of the structure of a motor device provided by an embodiment of the present application;

2 is a schematic flowchart of steps of a method for controlling a motor provided by an embodiment of the present application;

3 is a schematic flowchart of sub-steps of the motor control method in FIG. 1;

4 is a schematic flowchart of sub-steps of the motor control method in FIG. 1;

Fig. 5 is a schematic block diagram of a control circuit of a motor device provided by an embodiment of the present application;

6 is a schematic flowchart of steps of another motor control method provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a flow of starting a motor according to an embodiment of the present application;

8 is a schematic block diagram of the structure of a motor control device provided by an embodiment of the present application;

FIG. 9 is a schematic block diagram of the structure of a movable platform provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

The flowchart shown in the drawings is only an example, and does not necessarily include all contents and operations/steps, nor does it have to be executed in the described order. For example, some operations/steps can also be decomposed, combined or partially combined, so the actual execution order may be changed according to actual conditions.

Hereinafter, some embodiments of the present application will be described in detail with reference to the accompanying drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

When the motor is rotating at high speed, the microcontroller is reset due to a short interruption of power supply, the microcontroller is reset by electromagnetic interference, the prime mover drags the motor to a higher speed, etc. If the motor is rotating at high speed when the microcontroller is started Status, for permanent magnet motors controlled by a position sensorless control algorithm, if the microcontroller restarts due to reset when the motor is in a high-speed rotation state, because there is no position signal provided by the position sensor, the microcontroller's PWM cannot be directly enabled (Pulse Width Modulation) output, otherwise it may cause overcurrent of the switch tube and motor, causing damage to components or equipment. Therefore, when the microcontroller is started, the control program cannot determine whether the motor is rotating. Generally, the motor speed is zero by default at this time. Open-loop control is performed directly or the motor is driven to a certain speed by high-frequency injection. In this control mode, If the motor is actually running at high speed, there will be a higher rotor back-EMF at the motor end, so when the motor is driven by open-loop control or high-frequency injection, a large inrush current will be generated, which will make the motor speed down quickly. It may even cause damage to the electrical equipment.

For this situation, one solution is to wait for the motor to stop by itself, and then restart the motor. However, the process of stopping and restarting the motor may take a long time in some situations, such as the stopping and restarting of a large motor. The startup process takes several minutes to several hours, which is not allowed in some application scenarios. For example, the stalling of the drone's motor will directly cause the drone to crash.

Based on the above problems, the specification of this application provides a motor control method, device, equipment, and storage medium. The motor control method can be applied to electrical equipment. Please refer to FIG. 1. A schematic block diagram of the structure, as shown in Figure 1, the electrical equipment includes a housing 100, and a motor control device 200, a motor control circuit 300, and a motor 400 arranged in the housing 100. The motor 400 is used to provide power to the electrical equipment. The motor control device 200 and the motor control circuit 300 are used to control the operation of the motor 400. Wherein, the motor control circuit 300 includes a power supply (such as a DC power supply), an inverter circuit, a current sampling circuit, and a voltage sampling circuit. The inverter circuit includes a three-phase inverter bridge. The power supply is connected to the motor 400 via the three-phase inverter bridge. The motor 400 is respectively connected to a current sampling circuit and a voltage sampling circuit. The current sampling circuit is used to collect the current of the motor, and the voltage sampling circuit is used to collect the voltage of the motor; the motor control device 200 can obtain the current electrical angular velocity of the motor through the current voltage of the motor. If the electrical angular velocity is greater than or equal to the first preset threshold, the current electrical angular velocity of the motor is used as a feedback signal to perform closed-loop control on the motor to start the motor. In this way, a large inrush current is avoided when the motor is driven by the open-loop control or the high-frequency injection method, and there is no need to wait for the motor to stop before restarting the motor. Therefore, the accuracy and reliability of the motor control are improved. , Thereby improving the safety of electrical equipment.

Among them, electrical equipment includes electric vehicles, electric ships, unmanned vehicles, mobile robots, and drones.

Taking the electrical equipment as an unmanned aerial vehicle as an example, the unmanned aerial vehicle may have one or more propulsion units to allow the unmanned aerial vehicle to fly in the air. The one or more propulsion units can make the drone move at one or more, two or more, three or more, four or more, five or more, six or more free angles . In some cases, the drone can rotate around one, two, three, or more rotation axes. The rotation axes may be perpendicular to each other. The rotation axis can be maintained perpendicular to each other during the entire flight of the UAV. The rotation axis may include a pitch axis, a roll axis, and/or a yaw axis. The drone can move in one or more dimensions. For example, a drone can move upward due to the lifting force generated by one or more rotors. In some cases, the drone can move along the Z axis (upward relative to the drone direction), X axis, and/or Y axis (which can be lateral). The drone can move along one, two or three axes that are perpendicular to each other.

The drone can be a rotorcraft. In some cases, the drone may be a multi-rotor aircraft that may include multiple rotors. Multiple rotors can rotate to generate lift for the drone. The rotor can be a propulsion unit, allowing the drone to move freely in the air. The rotor can rotate at the same rate and/or can generate the same amount of lift or thrust. The rotor can rotate at different speeds at will, generating different amounts of lifting force or thrust and/or allowing the drone to rotate. In some cases, one, two, three, four, five, six, seven, eight, nine, ten or more rotors can be provided on the drone. These rotors can be arranged such that their rotation axes are parallel to each other. In some cases, the rotation axis of the rotors can be at any angle relative to each other, which can affect the movement of the drone.

The drone can have multiple rotors. The rotor can be connected to the main body of the drone, and the main body can include a control unit, an inertial measurement unit (IMU), a processor, a battery, a power supply, and/or other sensors. The rotor may be connected to the body by one or more arms or extensions branching from the central part of the body. For example, one or more arms may extend radially from the central body of the drone, and may have rotors at or near the end of the arms.

It can be understood that the above-mentioned naming of the components of the electrical equipment is only for identification purposes, and therefore does not limit the embodiments of the present application.

The motor control method provided in the embodiments of the present application will be described in detail below based on the electrical equipment, the control device of the motor in the electrical equipment, and the motor in the electrical equipment. It should be understood that the motor equipment in FIG. 1 does not constitute a limitation on the application scenario of the motor control method.

Please refer to FIG. 2, which is a schematic flowchart of a method for controlling a motor provided by an embodiment of the present application. This method can be used in the motor control device provided in the above embodiments to improve the accuracy and reliability of motor control, thereby improving the safety of the motor equipment.

As shown in Figure 2, the motor control method specifically includes steps S101 to S103.

S101: Before starting the motor, obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor.

Wherein, before the motor is started, the PWM signal for controlling the motor is not enabled or the power signal for driving the motor is not connected.

In one embodiment, the collected current electrical angular velocity of the motor is greater than 0, that is, the rotation speed of the motor is not zero before starting.

Wherein, the current voltage of the motor corresponds to the voltage of the motor line of the motor, for example, the voltage of the coil of the rotor winding of the motor.

Among them, the motor has no position sensor, that is, it is impossible to calculate the rotation speed of the motor through the position signal collected by the position sensor, and then to control the motor. The motor includes but is not limited to a permanent magnet synchronous motor. When starting the motor, first collect the current voltage of the motor. Optionally, the collected current voltage of the motor is a three-phase voltage.

Exemplarily, the motor is connected to a voltage sampling circuit, and the current voltage of the motor is collected through the voltage sampling circuit. For example, the input line of the rotor winding of the motor is connected to the voltage collection circuit to obtain the voltage of each winding. Optionally, the voltage sampling circuit includes a resistance component and an analog-to-digital converter. The current three-phase voltage analog signal of the motor can be collected through the resistance component, and the current three-phase voltage of the analog signal can be converted into a digital signal by the analog-digital converter. The current three-phase voltage.

In some embodiments, the motor control circuit between the motor and the DC power supply is provided with a three-phase inverter bridge, and the collecting the current voltage of the motor includes: controlling the disabled PWM (Pulse) of the three-phase inverter bridge. width modulation (pulse width modulation) signal, respectively collect the voltage of the negative terminal of the three-phase motor line of the motor relative to the DC bus of the DC power supply to obtain three opposite electromotive forces.

In this embodiment, the power supply is a DC power supply, and the motor is connected to the DC power supply via a three-phase inverter bridge through a three-phase motor line. In order to collect the current voltage of the motor and control the PWM signal of the disabled three-phase inverter bridge, that is, The PWM signal of the three-phase inverter bridge is not enabled, and then separately collect the voltage of the three-phase motor line of the motor relative to the negative terminal of the DC bus to obtain the three counter electromotive force of the motor. The three counter electromotive force is the current three-phase voltage of the motor.

In some other implementation manners, the collecting the current voltage of the motor includes: collecting the line voltage between any two-phase motor lines of the three-phase motor line of the motor to obtain three line voltages.

Different from the previous embodiment, in this embodiment, the three line voltages of the motor are obtained by collecting the line voltage between any two phases of the three-phase motor line of the motor, and the three line voltages are used as the current voltage of the motor. . Optionally, since the vector sum of the three-line voltages is zero, it is possible or only to collect any two line voltages among the three line voltages, and calculate the other line voltage based on the collected two line voltages.

For example, the three-phase motor line of the motor includes the first-phase motor line, the second-phase motor line, and the third-phase motor line. Collect the first-line voltage between the first-phase motor line and the second-phase motor line, and the second phase The second line voltage between the motor line and the third phase motor line is calculated based on the first line voltage and the second line voltage.

After that, the current electrical angular velocity of the motor is obtained according to the current voltage of the motor. Exemplarily, as shown in FIG. 3, the step S101 includes:

S1011. Obtain a voltage amplitude corresponding to the current voltage of the motor.

Taking obtaining the three-phase voltage of the motor as an example, specifically, according to the current three-phase voltage of the motor, the voltage vector synthesized by the three-phase voltage is determined, and the amplitude and phase of the voltage vector are obtained.

In some embodiments, after collecting the current voltage of the motor, the method further includes: performing Clarke transformation on the three opposite electromotive forces to generate a voltage vector, and obtaining the voltage amplitude and phase of the voltage vector.

For example, the current three counter electromotive force of the motor includes the first counter electromotive force, the second counter electromotive force and the third counter electromotive force. The first counter electromotive force, the second counter electromotive force and the third counter electromotive force are used as input parameters. The second and third opposite electromotive forces perform Clarke transformation to generate a corresponding voltage vector, and obtain the voltage amplitude and phase of the voltage vector.

In some other implementation manners, after collecting the current voltage of the motor, the method further includes: performing Clarke transformation on the three-wire voltage to generate a voltage vector to obtain the voltage amplitude and phase of the voltage vector.

If the collected current voltage of the motor is the line voltage, for example, the collected current line voltage of the motor includes the first line voltage, the second line voltage and the third line voltage, and the first line voltage, the second line voltage and the third line voltage are used as input parameters. Perform Clarke transformation on the first line voltage, the second line voltage and the third line voltage to generate the corresponding voltage vector, and obtain the voltage amplitude and phase of the voltage vector.

S1012. Calculate the electrical angular velocity according to the voltage amplitude.

In some embodiments, the electrical angular velocity of the motor is calculated according to the voltage amplitude corresponding to the current voltage of the motor. Specifically, the calculating the electrical angular velocity according to the voltage amplitude includes: obtaining the flux linkage parameter value of the motor; dividing the voltage amplitude by the flux linkage parameter value to calculate and obtain the electrical angular velocity Angular velocity.

Among them, the flux parameter λf is the motor parameter, which represents the magnetic flux of the motor. By obtaining the voltage amplitude corresponding to the current voltage of the motor and the flux parameter value corresponding to the motor flux parameter λf, the voltage amplitude is divided by the flux parameter λf corresponds to the flux linkage parameter value, and calculates the electrical angular velocity of the motor.

In other embodiments, as shown in FIG. 4, the step S101 includes:

S1013: Detect a phase change value of the motor within a preset time period.

S1014. Divide the phase change value by the preset duration to obtain the electrical angular velocity by calculation.

In this embodiment, there is no need to obtain the flux parameter value corresponding to the flux parameter λf of the motor, but it is only necessary to detect the phase change value of the motor within the preset time period, and divide the phase change value by the preset time period to calculate the motor Electrical angular velocity. Among them, the preset duration can be set based on actual conditions, which is not specifically limited in this application. For example, the first voltage of the motor is collected by a voltage sampling circuit, and the second voltage of the motor is collected by the voltage sampling circuit after a preset period of time. Set the duration.

Specifically, the first phase of the motor is determined according to the first voltage, that is, the voltage vector generated after the clark transformation of the first three-phase voltage is determined, and the phase of the voltage vector is obtained as the first phase of the motor; according to the second three-phase voltage Determine the second phase of the motor, that is, determine the voltage vector generated by the clark transformation of the second three-phase voltage, and obtain the phase of the voltage vector as the second phase of the motor; determine the motor's phase according to the first and second phases The amount of phase change is to determine the difference between the first phase and the second phase, and use the difference between the first phase and the second phase as the phase change of the motor. Then, the difference between the first phase and the second phase is used as the phase change amount of the motor divided by the preset duration to calculate the electrical angular velocity of the motor. In this way, there is no need to obtain the motor flux parameter λf, that is, the workload of obtaining the electrical angular velocity of the motor is reduced.

S102. If the electrical angular velocity is greater than or equal to a first preset threshold, use the electrical angular velocity as a feedback signal to perform closed-loop control on the motor to start the motor; wherein the first preset threshold is greater than zero.

The first preset threshold corresponding to the electrical angular velocity of the motor used for quick start control of the operation of the motor is preset, and after the current electrical angular velocity of the motor is obtained, the electrical angular velocity is compared with the first preset threshold to determine the two The size of the person. If the current electrical angular velocity of the motor is greater than or equal to the first preset threshold, that is, when the motor is running at a high speed, the electrical angular velocity of the motor is used as a feedback signal to perform closed-loop control of the motor to start the motor.

Specifically, as shown in Figure 5, the control device for setting the motor is configured with a position observer, a speed controller, a current controller, and SVM (Support Vector Machine). The current electrical angular velocity of the motor is

Phase is

Electrical angular velocity

And phase

As the initial value assigned to the position observer, the position observer will

As a feedback signal to the speed controller, combined with the electrical angular velocity

And input control signal, such as the speed command w ^* , the speed controller outputs the corresponding current signal

To the current controller, the current controller according to

Output the corresponding voltage signal u _αβ to the position observer, and enable the PWM signal of the three-phase inverter bridge through the SVM, and use the position observer to calculate the position of the motor rotor and the electrical angular velocity of the motor according to the back EMF method to control the motor switching To the calculated position of the motor rotor and the electrical angular velocity of the motor. Among them, the position of the motor rotor and the electrical angular velocity (or rotation speed) of the motor calculated according to the back EMF method are already very mature technical means, so I will not repeat them here.

In some embodiments, the electrical angular velocity is used as a feedback signal, and the motor performs closed-loop control to start the motor. Specifically, the electrical angular velocity and the phase are used as feedback signals to perform closed-loop control on the motor. To start the motor.

The difference between this embodiment and the closed-loop control in the above-mentioned embodiment is that the electrical angular velocity and phase of the motor are used as feedback signals to perform closed-loop control on the motor to start the motor. The specific closed-loop control process can refer to the process of closed-loop control using the electrical angular velocity of the motor as the feedback signal, so I will not repeat it here. In this embodiment, since the feedback signal includes the electrical angular velocity and phase of the motor, the reliability of the closed-loop control of the motor is further improved.

In some embodiments, the control method of the motor further includes: collecting the current current of the motor, and correcting the electrical angular velocity and the phase through the current until the electrical angular velocity and the electrical angular velocity are corrected. The phase is floating within a preset range.

In this embodiment, the current current of the motor is collected by the current sampling circuit. Illustratively, a current sensor is provided on the current sampling circuit, and collecting the current current of the motor is specifically collecting the current current of the motor through the current sensor.

By collecting the current of the motor, the electrical angular velocity and phase of the motor are corrected according to the current of the motor until the electrical angular velocity and phase of the corrected motor float within a preset range. It should be noted that the current voltage of the motor used to obtain the electrical angular velocity of the motor is the collected and detected voltage, and the PWM signal of the three-phase inverter bridge is still not enabled at this time. Specifically, for example, as shown in Figure 5, the current sampling circuit collects the current three-phase current of the motor, takes the three-phase current as the input parameter and performs Clarke transformation to generate the corresponding current vector i _αβ , and the motor is adjusted according to the current vector i _αβ. The electrical angular velocity and phase are corrected until the corrected electrical angular velocity and phase of the motor float within the preset range.

For example, preset the first preset range corresponding to the electrical angular velocity of the motor and the second preset range corresponding to the phase. By continuously collecting the current of the motor, the electrical angular velocity and phase of the motor are continuously corrected based on the current of the motor until after the correction. The electrical angular velocity of the motor is floating in the first preset range, and the phase is floating in the second preset range. Then use the corrected electrical angular velocity and phase of the motor as the feedback signal to perform closed-loop control on the motor to start the motor, that is, use the stable electrical angular velocity and phase as the feedback signal to perform closed-loop control on the motor, so the motor is closed-loop controlled The reliability is further improved.

In some embodiments, as shown in FIG. 6, after the step S101, the method further includes:

S103: If the electrical angular velocity is less than the first preset threshold and greater than the second preset threshold, continue to collect the electrical angular velocity until the electrical angular velocity is less than or equal to the second preset threshold.

The above-mentioned control of the motor is directed to the control of the motor in the case of high-speed operation, that is, the control of the motor in the case that the electrical angular velocity of the motor is greater than the first preset threshold. It should be noted that since the current electrical angular velocity of the motor is greater than 0, and the motor control device does not apply (ie, disable) the PWM signal of the three-phase inverter bridge, the current electrical angular velocity of the motor will decrease over time. The following specifically describes the control of the motor when the electrical angular velocity of the motor is less than the first preset threshold. In order to avoid a large inrush current when the motor is being dragged, a second preset threshold corresponding to the electrical angular velocity of the motor is also preset. Wherein, the first preset threshold is greater than the second preset threshold. When the electrical angular velocity of the motor is less than the first preset threshold and greater than the second preset threshold, the current voltage of the motor is continuously collected, and the electrical angular velocity of the motor is calculated and determined according to the collected current voltage of the motor, and the electrical angular velocity of the motor is compared with the first The preset threshold value is compared with the second preset threshold value until the current latest electrical angular velocity of the motor is less than or equal to the second preset threshold value.

S104: When the electrical angular velocity is less than or equal to the second preset threshold, open-loop control or use a high-frequency injection method to run the motor to a preset rotation speed.

When the electrical angular velocity of the motor is less than or equal to the second preset threshold, that is, when the electrical angular velocity of the motor reaches a safe speed, the open-loop control or the high-frequency injection method is used to run the motor to the preset speed. Using open loop control or high frequency injection method to drive the motor is a conventional technology, so I won't repeat it here. Or, the specific value of the preset speed can be flexibly set according to the actual situation, and there is no restriction here.

S105: When the motor runs to the preset speed, the closed-loop control is used to control the motor again.

After the motor is dragged to the preset speed for operation, the closed-loop control is used to control the motor. For example, the electrical angular velocity of the motor is obtained by the back-EMF method, and then the electrical angular velocity of the motor is used as a feedback signal to perform closed-loop control on the operation of the motor.

For example, as shown in Figure 7, the motor startup control process is as follows:

After the motor system is initialized, the PWM signal of the three-phase inverter bridge is first disabled to collect the current voltage of the motor, and obtain the voltage amplitude and phase corresponding to the current voltage of the motor, and determine the current electrical angular velocity of the motor according to the current voltage of the motor. Then it is judged whether the electrical angular velocity is greater than the first preset threshold, that is, whether the electrical angular velocity of the motor meets the requirements of the motor's fast start. The output of the observer, or the position observer according to the vector current to correct the electrical angular velocity and phase calculated from the vector voltage, output the final electrical angular velocity and phase, and enable the PWM signal of the three-phase inverter bridge. The motor is switched to the position of the motor rotor calculated based on the back-EMF method and the electrical angular velocity (or rotation speed) of the motor, and the motor is closed-loop controlled. Conversely, if it is judged that the electrical angular velocity is less than the first preset threshold, that is, it is judged that the electrical angular velocity of the motor does not meet the requirements for quick start of the motor, then it is judged whether the electrical angular velocity of the motor is less than or equal to the second preset threshold, that is, whether the electrical angular velocity of the motor is When the safe speed is reached, if the electrical angular speed of the motor is greater than the second preset threshold, that is, the electrical angular speed of the motor does not reach the safe speed, the electrical angular speed of the motor is continuously collected until the electrical angular speed of the motor is less than or equal to the second preset threshold. That is, the electrical angular speed of the motor reaches the safe speed. At this time, the PWM signal of the three-phase inverter bridge is enabled, and then the open-loop control or high-frequency injection method is used to obtain the position of the motor rotor to drive the motor to the preset speed. Then switch the motor to the position of the motor rotor and the electrical angular velocity (or rotation speed) of the motor calculated based on the back-EMF method to perform closed-loop control of the motor.

In some embodiments, the method for controlling the motor further includes: when the motor is started, obtaining the current electrical angular velocity of the motor by obtaining the actual output voltage signal used to control the motor, and using the electrical angular velocity The motor is controlled as a feedback signal.

After the motor is started by the above control method, the actual output voltage signal used to control the motor is obtained, for example, the voltage signal u _αβ output by the current controller as shown in Fig. 5 is based on the actual output voltage used to control the motor Signal to obtain the current electrical angular velocity of the motor. Specifically, still taking Figure 5 as an example, the current controller outputs a voltage signal u _αβ to the position observer, and the position observer obtains the current electrical angular velocity of the motor _{based on the voltage signal u αβ.} After that, the electrical angular velocity of the motor is used as a feedback signal to control the operation of the motor in a closed loop. The method of obtaining the electrical angular velocity and the method of using the electrical angular velocity of the motor as the feedback signal to perform the closed-loop control of the motor can refer to the above-mentioned operation during the starting process of the motor, so it will not be repeated here. That is, after the motor is started, closed-loop control is also performed according to the electrical angular velocity of the motor as a feedback signal, thus improving the reliability of the operation after the motor is started.

In the motor control method provided in the above embodiment, the motor has no position sensor. When the motor is started, the current electrical angular velocity of the motor is obtained by collecting the current voltage of the motor. If the electrical angular velocity is greater than or equal to the first preset threshold, that is When the motor is running fast, the current electrical angular velocity of the motor is used as the feedback signal to perform closed-loop control of the motor to start the motor. It is not necessary to wait for the motor to stop before restarting the motor, and it also avoids open-loop control or the use of high frequency The injection method generates a large inrush current when the motor is dragged. Therefore, the accuracy and reliability of the motor control are improved, and the safety of the motor equipment is further improved.

Please refer to FIG. 8, which is a schematic block diagram of a structure of a motor control device provided by an embodiment of the present application. The motor control device 800 includes a processor 801 and a memory 802, and the processor 801 and the memory 802 are connected through a bus 803. The bus 803 is, for example, an I2C (Inter-integrated Circuit) bus. The motor control device 800 is applied to motor equipment. The motor equipment includes a motor control circuit and a motor. The motor is used to provide power to the motor equipment. The motor control device 800 and the circuit control circuit are used to control the operation of the motor. The motor control circuit includes power supply. Power supply (such as DC power supply), inverter circuit, current sampling circuit and voltage sampling circuit. The inverter circuit includes a three-phase inverter bridge. The power supply is connected to the motor through the three-phase inverter bridge. The motor is connected to the current sampling circuit and the voltage sampling circuit respectively. Circuit connection, the current sampling circuit is used to collect the current of the motor, and the voltage sampling circuit is used to collect the voltage of the motor; the motor control device can obtain the current electrical angular velocity of the motor through the current voltage of the motor, if the electrical angular velocity is greater than or equal to the first preset Threshold, the current electrical angular velocity of the motor is used as the feedback signal to perform closed-loop control of the motor to start the motor. In this way, it avoids the large inrush current when the motor is driven by the open loop control or the high frequency injection method, and there is no need to wait for the motor to stop before restarting the motor. Therefore, the accuracy and reliability of the motor control are improved. , Thereby improving the safety of electrical equipment.

Taking the electrical equipment as an unmanned aerial vehicle as an example, the unmanned aerial vehicle may have one or more propulsion units to allow the unmanned aerial vehicle to fly in the air. The one or more propulsion units can make the drone move at one or more, two or more, three or more, four or more, five or more, six or more free angles . In some cases, the drone can rotate around one, two, three, or more rotation axes. The rotation axes may be perpendicular to each other. The rotation axis can be maintained perpendicular to each other during the entire flight of the UAV. The rotation axis may include a pitch axis, a roll axis, and/or a yaw axis. The drone can move in one or more dimensions. For example, drones can move upwards due to the lifting force generated by one or more rotors. In some cases, the drone can move along the Z axis (upward relative to the drone direction), X axis, and/or Y axis (which can be lateral). The drone can move along one, two or three axes that are perpendicular to each other.

Specifically, the processor 801 may be a micro-controller unit (MCU), a central processing unit (Central Processing Unit, CPU), a digital signal processor (Digital Signal Processor, DSP), or the like.

Specifically, the memory 802 may be a Flash chip, a read-only memory (ROM, Read-Only Memory) disk, an optical disk, a U disk, or a mobile hard disk.

Wherein, the processor 801 is configured to run a computer program stored in the memory 802, and implement the following steps when executing the computer program:

In some embodiments, when the processor implements the acquisition of the current electrical angular velocity of the motor, it specifically implements:

Acquiring a voltage amplitude corresponding to the current voltage of the motor;

According to the voltage amplitude, the electrical angular velocity is calculated.

In some embodiments, the motor is connected to a voltage sampling circuit, and when the processor implements the collection of the current voltage of the motor, it specifically implements:

Collect the current voltage of the motor through the voltage sampling circuit.

In some embodiments, a three-phase inverter bridge is provided on the line between the motor and the power supply, and when the processor implements the collection of the current voltage of the motor, it specifically implements:

The PWM signal of the three-phase inverter bridge is controlled to disable, and the voltage of the three-phase motor line of the motor relative to the negative terminal of the DC bus is respectively collected to obtain three opposite electromotive forces.

In some embodiments, after the processor implements the collection of the current voltage of the motor, it further implements:

Clarke transforms the three opposite electromotive forces to generate a voltage vector, and obtains the voltage amplitude and phase of the voltage vector.

In some embodiments, when the processor implements the collection of the current voltage of the motor, it specifically implements:

Collect the line voltage between any two-phase motor lines in the three-phase motor lines of the motor to obtain the three-line voltage.

Perform Clarke transformation on the three-wire voltage to generate a voltage vector, and obtain the voltage amplitude and phase of the voltage vector.

In some embodiments, the processor performs closed-loop control of the motor using the electrical angular velocity as a feedback signal to start the motor; wherein, when the first preset threshold is greater than zero, Implementation:

The electrical angular velocity and the phase are used as feedback signals to perform closed-loop control on the motor to start the motor; wherein, the first preset threshold is greater than zero.

In some embodiments, when the processor implements the calculation of the electrical angular velocity according to the voltage amplitude, it specifically implements:

Obtaining the value of the flux linkage parameter of the motor;

The voltage amplitude is divided by the flux linkage parameter value to obtain the electrical angular velocity by calculation.

Detecting the phase change value of the motor within a preset time period;

The phase change value is divided by the preset duration to obtain the electrical angular velocity by calculation.

In some embodiments, the processor further implements when executing the computer program:

Collect the current current of the motor, and correct the electrical angular velocity and the phase through the current until the corrected electrical angular velocity and the phase float within a preset range.

In some embodiments, the motor is connected to a current sensor, and when the processor implements the collection of the current current of the motor, it specifically implements:

The current current of the motor is collected by the current sensor.

After the motor is started, the current electrical angular velocity of the motor is obtained by obtaining the actual output voltage signal used to control the motor, and the electrical angular velocity is used as a feedback signal to control the motor.

In some embodiments, a three-phase inverter bridge is provided on the line between the motor and the power supply, and after the processor realizes the acquisition of the current electrical angular velocity of the motor, it further realizes:

When the motor is started, if the electrical angular velocity is less than the first preset threshold and greater than the second preset threshold, the electrical angular velocity is continuously collected until the electrical angular velocity is less than or equal to the second preset Threshold

When the electrical angular velocity is less than or equal to the second preset threshold, the motor is operated to a preset rotation speed through open-loop control or a high-frequency injection method;

When the motor runs to the preset speed, the closed-loop control is used to control the motor again;

Wherein, the first preset threshold is greater than the second preset threshold.

It should be noted that those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working process of the motor control device described above can refer to the corresponding process in the foregoing motor control method embodiment. This will not be repeated here.

The embodiments of the present application also provide a movable platform, and the movable platform may be a UAV 110 drone or the like. Please refer to FIG. 9, which is a schematic block diagram of the structure of a movable platform provided by an embodiment of the present application. As shown in FIG. 9, the movable platform includes a body 901, a power system 902 provided in the body 901, and one or more A processor 903. Wherein, the power system 902 is used to provide power for the movable platform, the power system 902 includes one or more motors; the one or more processors 903 are used to start the motors of the power system 902 by collecting the current The voltage obtains the current electrical angular velocity of the motor, and if the electrical angular velocity is greater than or equal to the first preset threshold, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor.

Exemplarily, the movable platform may also perform wireless communication with the remote control device and the display device.

Specifically, taking the UAV 110 as the movable platform as an example, the UAV 110 also includes a flight control system and a frame. The frame may include a fuselage and a tripod (also called a landing gear). The fuselage may include a center frame and one or more arms connected to the center frame, and the one or more arms extend radially from the center frame. The tripod is connected to the fuselage and is used for supporting the UAV when landing.

The power system 902 may also include an electronic governor (referred to as an ESC for short) and one or more propellers. Among them, one or more processors 903 may be provided in the electronic governor, and one or more propellers correspond to one or more propellers. Multiple motors, the motor is connected between the electronic governor and the propeller, the motor and the propeller are arranged on the corresponding arm; the electronic governor is used to receive the driving signal generated by the flight control system, and provide the driving current to the motor according to the driving signal To control the speed of the motor. The motor is used to drive the propeller to rotate to provide power for the flight of the UAV 110. This power enables the UAV 110 to achieve one or more degrees of freedom of movement. It should be understood that the motor may be a DC motor or an AC motor. In addition, the motor can be a brushless motor or a brush motor.

It should be noted that, for the convenience and conciseness of description, the specific working process of the motor in the movable platform can refer to the corresponding process in the foregoing embodiment of the motor control method, which will not be repeated here.

By setting the voltage sampling circuit corresponding to the motor, it is used to collect the voltage of the motor. When a movable platform such as a drone is flying in the air, when the motor needs to be restarted due to signal interference and other reasons, the inverter bridge will be disabled first. For all PWM signals, the current voltage of the motor is collected by the voltage sampling circuit to obtain the current electrical angular velocity of the motor, and when the electrical angular velocity is greater than or equal to the first preset threshold, that is, when the motor is running at high speed, the current electrical angular velocity of the motor is used as feedback Signal, the closed-loop control of the motor, start the motor, do not need to wait for the motor to stop and then restart the motor, so as to avoid the situation of the drone and other movable platforms falling due to the motor stop; In the process of quick start, open-loop control is directly carried out or the high-frequency injection method is directly used to drag the motor, which causes the problem of damage to the movable platform such as drones due to the current impact, which can realize the rapid control of the permanent magnet motor in high-speed rotation. Therefore, the safety and stability of flying on movable platforms such as unmanned aerial vehicles are improved.

The embodiments of the present application also provide a computer-readable storage medium, the computer-readable storage medium stores a computer program, the computer program includes program instructions, and the processor executes the program instructions to implement the foregoing implementation The example provides the steps of the motor control method.

Wherein, the computer-readable storage medium may be the electrical equipment or the control device of the motor or the internal storage unit of the movable platform described in any of the foregoing embodiments, for example, the electrical equipment or the control device of the motor or the internal storage unit of the movable platform. Hard disk or memory. The computer-readable storage medium may also be the electrical equipment or the control device of the motor or the external storage device of the movable platform, for example, the electrical equipment or the control device of the motor or the plug-in hard disk equipped on the movable platform, Smart Memory Card (Smart Media Card, SMC), Secure Digital (SD) card, Flash Card (Flash Card), etc.

It should be understood that the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in the specification of this application and the appended claims, unless the context clearly indicates other circumstances, the singular forms "a", "an" and "the" are intended to include plural forms.

It should also be understood that the term "and/or" used in the specification and appended claims of this application refers to any combination of one or more of the items listed in the associated and all possible combinations, and includes these combinations.

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed in this application. Modifications or replacements, these modifications or replacements shall be covered within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

A control method of a motor, characterized in that the motor has no position sensor, and the control method includes:

Before starting the motor, obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor;

If the electrical angular velocity is greater than or equal to a first preset threshold, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor; wherein the first preset threshold is greater than zero.
The method according to claim 1, wherein the obtaining the current electrical angular velocity of the motor comprises:

Acquiring a voltage amplitude corresponding to the current voltage of the motor;

According to the voltage amplitude, the electrical angular velocity is calculated.
The method according to claim 1, wherein the motor is connected to a voltage sampling circuit, and the collecting the current voltage of the motor comprises:

Collect the current voltage of the motor through the voltage sampling circuit.
The method according to claim 1, wherein a three-phase inverter bridge is provided on the line between the motor and the DC power supply, and the collecting the current voltage of the motor includes:

The PWM signal of the three-phase inverter bridge is controlled to disable, and the voltage of the negative terminal of the three-phase motor line of the motor relative to the negative terminal of the DC bus of the DC power supply is respectively collected to obtain three opposite electromotive forces.
The method according to claim 4, wherein after the collecting the current voltage of the motor, the method further comprises:

Clarke transforms the three opposite electromotive forces to generate a voltage vector, and obtains the voltage amplitude and phase of the voltage vector.
The method according to claim 1, wherein the collecting the current voltage of the motor comprises:

Collect the line voltages between any two-phase motor lines in the three-phase motor lines of the motor to obtain three line voltages.
The method according to claim 6, wherein after the collecting the current voltage of the motor, the method further comprises:

Perform Clarke transformation on the three line voltages to generate a voltage vector, and obtain the voltage amplitude and phase of the voltage vector.
The method according to claim 5 or 7, wherein the using the electrical angular velocity as a feedback signal to perform closed-loop control on the motor to start the motor specifically includes:

The electrical angular velocity and the phase are used as feedback signals to perform closed-loop control on the motor to start the motor.
The method according to claim 2, wherein the calculating the electrical angular velocity according to the voltage amplitude comprises:

Obtaining the value of the flux linkage parameter of the motor;

The voltage amplitude is divided by the flux linkage parameter value to obtain the electrical angular velocity by calculation.
The method according to claim 1, wherein the obtaining the current electrical angular velocity of the motor comprises:

Detecting the phase change value of the motor within a preset time period;

The phase change value is divided by the preset duration to obtain the electrical angular velocity by calculation.
The method according to claim 8, wherein the method further comprises:

Collect the current current of the motor, and correct the electrical angular velocity and the phase through the current until the corrected electrical angular velocity and the phase float within a preset range.
The method according to claim 11, wherein the motor is connected to a current sensor, and the collecting the current current of the motor specifically includes:

The current current of the motor is collected by the current sensor.
The method according to claim 1, wherein the method further comprises:

After the motor is started, the electrical angular velocity is obtained by obtaining the actual output voltage signal used to control the motor, and the electrical angular velocity is used as a feedback signal to control the motor.
The method according to claim 1, wherein after the obtaining the current electrical angular velocity of the motor, the method further comprises:

Before the motor is started, if the electrical angular velocity is less than the first preset threshold and greater than the second preset threshold, the electrical angular velocity is continuously collected until the electrical angular velocity is less than or equal to the second preset threshold. Set threshold

When the electrical angular velocity is less than or equal to the second preset threshold, the motor is operated to the preset rotation speed through open-loop control or a high-frequency injection method;

When the motor runs to the preset speed, the closed-loop control is used to control the motor again;

Wherein, the first preset threshold is greater than the second preset threshold.
A control device of a motor, characterized in that the control device of the motor includes a memory and a processor;

The memory is used to store a computer program;

The processor is configured to execute the computer program and, when executing the computer program, implement the following steps:

Before starting the motor, obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor;

If the electrical angular velocity is greater than or equal to a first preset threshold, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor; wherein the first preset threshold is greater than zero.
The device according to claim 15, wherein when the processor implements the acquisition of the current electrical angular velocity of the motor, it specifically implements:

Acquiring a voltage amplitude corresponding to the current voltage of the motor;

According to the voltage amplitude, the electrical angular velocity is calculated.
The device according to claim 15, wherein the motor is connected to a voltage sampling circuit, and when the processor implements the collection of the current voltage of the motor, it specifically implements:

Collect the current voltage of the motor through the voltage sampling circuit.
The device according to claim 15, wherein a three-phase inverter bridge is provided on the line between the motor and the DC power supply, and when the processor realizes the collection of the current voltage of the motor, it specifically implements :

The PWM signal of the three-phase inverter bridge is controlled to disable, and the voltage of the negative terminal of the three-phase motor line of the motor relative to the negative terminal of the DC bus of the DC power supply is respectively collected to obtain three opposite electromotive forces.
The device according to claim 18, wherein after the processor implements the collection of the current voltage of the motor, it further implements:

Clarke transforms the three opposite electromotive forces to generate a voltage vector, and obtains the voltage amplitude and phase of the voltage vector.
The device according to claim 15, wherein when the processor implements the collection of the current voltage of the motor, it specifically implements:

Collect the line voltages between any two-phase motor lines in the three-phase motor lines of the motor to obtain three line voltages.
The device according to claim 20, wherein after the processor implements the collection of the current voltage of the motor, it further implements:

Perform Clarke transformation on the three line voltages to generate a voltage vector, and obtain the voltage amplitude and phase of the voltage vector.
The device according to claim 19 or 21, wherein the processor implements the closed-loop control of the motor by using the electrical angular velocity as a feedback signal to start the motor, which specifically implements:

The electrical angular velocity and the phase are used as feedback signals to perform closed-loop control on the motor to start the motor.
The device according to claim 16, wherein when the processor implements the calculation of the electrical angular velocity according to the voltage amplitude, it specifically implements:

Obtaining the value of the flux linkage parameter of the motor;

The voltage amplitude is divided by the flux linkage parameter value to obtain the electrical angular velocity by calculation.
The device according to claim 15, wherein when the processor implements the acquisition of the current electrical angular velocity of the motor, it specifically implements:

Detecting the phase change value of the motor within a preset time period;

The phase change value is divided by the preset duration to obtain the electrical angular velocity by calculation.
The device according to claim 22, wherein when the processor executes the computer program, it further implements:

Collect the current current of the motor, and correct the electrical angular velocity and the phase through the current until the corrected electrical angular velocity and the phase float within a preset range.
The device according to claim 25, wherein the motor is connected to a current sensor, and when the processor implements the collection of the current current of the motor, it specifically implements:

The current current of the motor is collected by the current sensor.
The device according to claim 15, wherein when the processor executes the computer program, it further implements:

After the motor is started, the current electrical angular velocity of the motor is obtained by obtaining the actual output voltage signal used to control the motor, and the electrical angular velocity is used as a feedback signal to control the motor.
The device according to claim 15, wherein after the processor implements said obtaining the current electrical angular velocity of the motor, it further implements:

When the motor is started, if the electrical angular velocity is less than the first preset threshold and greater than the second preset threshold, the electrical angular velocity is continuously collected until the electrical angular velocity is less than or equal to the second preset Threshold

When the electrical angular velocity is less than or equal to the second preset threshold, the motor is operated to the preset rotation speed through open-loop control or a high-frequency injection method;

When the motor runs to the preset speed, the closed-loop control is used to control the motor again;

Wherein, the first preset threshold is greater than the second preset threshold.
An electrical equipment, characterized in that, the electrical equipment includes:

case;

A motor arranged in the housing;

And the motor control device according to any one of claims 15 to 28, wherein the motor control device is in communication connection with the motor.
A movable platform, characterized in that, the movable platform includes:

Body

A power system is provided in the body, the power system is used to provide power to the movable platform, and the power system includes a motor;

And one or more processors, configured to obtain the current electrical angular velocity of the motor by collecting the current voltage of the motor before starting the motor; if the electrical angular velocity is greater than or equal to a first preset threshold, Then, the electrical angular velocity is used as a feedback signal to perform closed-loop control on the motor to start the motor; wherein, the first preset threshold is greater than zero.
A computer-readable storage medium, characterized in that, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor realizes as described in any one of claims 1 to 14 The control method of the motor described.