阅读说明：本技术 步进电机的驱动控制装置和驱动控制方法 (Drive control device and drive control method for stepping motor ) 是由 万心 于 2020-06-17 设计创作，主要内容包括：本发明提供了一种电机驱动控制装置和驱动控制方法。基于本发明,可以利用检测到的步进电机的相电压和相电流可以确定步进电机的反电动势,并且可以根据步进电机的反电动势确定步进电机的转速,由此实现对步进电机的无感观测；根据以无感观测方式确定的转速,可以调节逆变驱动模块对步进电机产生的驱动功率,以通过电压补偿、或电压补偿与电流补偿的结合而使驱动功率跟随于与转速相匹配的负载变化而自适应变化,以避免步进电机失步。而且,根据以无感观测方式确定的转速,还可以在转速过低时切换至较低的驱动功率以减少步进电机的功耗。(The invention provides a motor drive control device and a drive control method. Based on the invention, the detected phase voltage and phase current of the stepping motor can be used for determining the back electromotive force of the stepping motor, and the rotating speed of the stepping motor can be determined according to the back electromotive force of the stepping motor, thereby realizing the non-inductive observation of the stepping motor; according to the rotating speed determined in a non-inductive observation mode, the driving power generated by the inverter driving module on the stepping motor can be adjusted, so that the driving power can be adaptively changed along with the load change matched with the rotating speed through voltage compensation or the combination of the voltage compensation and the current compensation, and the stepping motor is prevented from being out of step. Furthermore, depending on the rotational speed determined in a sensorless manner, it is also possible to switch to a lower drive power when the rotational speed is too low in order to reduce the power consumption of the stepper motor.)

1. A drive control device of a stepping motor, comprising:

the inverter driving module is used for generating driving power for the stepping motor;

the speed measurement sampling module is used for detecting phase voltage and phase current of the stepping motor from the inversion driving module;

the driving control module is used for determining the zero-crossing period of the back electromotive force of the stepping motor by using the detected phase voltage and phase current; determining the rotating speed of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor; and according to the rotating speed of the stepping motor, adjusting the driving power generated by the inversion driving module on the stepping motor, wherein:

when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, providing voltage compensation for the driving voltage of the inversion driving module so as to make up the power difference of the driving power compared with the load increment caused by the increase of the rotating speed;

and when the rotating speed is greater than a preset second high-speed threshold, providing current compensation for the driving current of the inversion driving module on the basis of voltage compensation so as to make up the power difference of the driving power based on the voltage compensation compared with the load increment.

2. The driving control device of claim 1, further comprising a voltage regulation module, and wherein the driving control module further generates a voltage compensation signal to the voltage regulation module, wherein the voltage compensation signal is used for the driving voltage regulation module to boost a voltage value of the driving voltage provided for the inverter driving module to a compensation voltage value greater than a rated voltage value.

3. The driving control device according to claim 2, wherein the driving control module further generates a PWM signal with a compensation duty ratio to the inverter driving module during the period of generating the voltage compensation signal, wherein the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to a preset second high-speed threshold value, so as to increase the turn-on amplitude of the on-state switch of each phase bridge arm in the inverter driving module.

4. The driving control device according to claim 2, further comprising a PWM driving module, and the driving control module further generates a current compensation signal to the PWM driving module during the period of generating the voltage compensation signal, wherein the current compensation signal is used to control the PWM driving module to generate a PWM signal with a compensation duty ratio to the inverter driving module, and the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to a preset second high-speed threshold value, so as to increase the turn-on amplitude of the on-state switch of each phase of the bridge arm in the inverter driving module.

5. The driving control device as claimed in claim 1, wherein the driving control module is further configured to adjust the driving voltage of the inverter driving module to be less than a rated voltage value when the rotation speed is less than a preset low speed threshold value, so as to reduce power consumption of the stepping motor.

6. The drive control device of claim 5, further comprising a voltage regulation module, wherein the voltage regulation module comprises a first power source and a second power source that are alternatively enabled:

when the rotating speed is greater than or equal to a preset low-speed threshold and less than or equal to a preset first high-speed threshold, the driving control module generates a first power supply selection signal to the voltage regulation module, wherein the first power supply selection signal is used for starting a first power supply to provide driving voltage with a voltage value of a rated voltage value for the inversion driving module;

when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, the driving control module generates a first power supply selection signal and a voltage compensation signal to the voltage regulation module, wherein the voltage compensation signal is used for driving the first power supply to increase the voltage value of the driving voltage provided for the inversion driving module to a compensation voltage value greater than a rated voltage value;

when the rotating speed is smaller than the preset low-speed threshold value, the driving control module further generates a second power supply selection signal to the voltage regulating module, and the driving voltage of the inversion driving module is regulated to be smaller than the rated voltage value when the rotating speed falls within the preset first high-speed threshold value, wherein the second power supply selection signal is used for starting a second power supply to provide the driving voltage with the voltage value smaller than the rated voltage value for the inversion driving module.

7. A drive control method of a stepping motor, characterized by comprising:

determining a zero-crossing period of a back electromotive force of the stepping motor by using the phase voltage and the phase current of the stepping motor detected from the inverter driving module;

determining the rotating speed of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor;

according to step motor's rotational speed, adjust the drive power that contravariant drive module produced step motor, wherein:

when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, providing voltage compensation for the driving voltage of the inversion driving module so as to make up the power difference of the driving power compared with the load increment caused by the increase of the rotating speed;

when the rotating speed is greater than a preset first high-speed threshold and exceeds a preset second high-speed threshold, current compensation is provided for the driving current of the inversion driving module on the basis of voltage compensation, so that the power difference of the driving power based on the voltage compensation compared with the load increment is made up.

8. The drive control method according to claim 7, wherein providing voltage compensation to the driving voltage of the inverter driving module comprises:

and generating a voltage compensation signal to the voltage regulation module, wherein the voltage compensation signal is used for driving the voltage regulation module to increase the voltage value of the driving voltage provided for the inversion driving module to a compensation voltage value larger than the rated voltage value.

9. The drive control method of claim 8, wherein providing current compensation for the driving current of the inverter driving module on the basis of the voltage compensation comprises:

and in the period of generating the voltage compensation signal, generating a PWM signal with a compensation duty ratio to the inversion driving module, wherein the compensation duty ratio of the PWM signal is greater than the rated duty ratio of the PWM signal when the rotating speed is less than or equal to a preset second high-speed threshold value, so as to improve the opening amplitude of the conducting switch of each phase of bridge arm in the inversion driving module.

10. The drive control method of claim 8, wherein providing current compensation for the driving current of the inverter driving module on the basis of the voltage compensation comprises:

and generating a current compensation driving signal to the PWM driving module in a period of keeping generating a voltage compensation signal to the voltage regulating module, wherein the current compensation driving signal is used for controlling the PWM driving module to generate a PWM signal with a compensation duty ratio to the inversion driving module, and the compensation duty ratio of the PWM signal is larger than a rated duty ratio of the PWM signal when the rotating speed is less than or equal to a preset second high-speed threshold value, so as to improve the opening amplitude of a conducting switch of each phase of bridge arm in the inversion driving module.

Technical Field

The present invention relates to a motor driving technology, and more particularly, to a driving control device and a driving control method for a stepping motor.

Background

The drive control of the stepping motor usually adopts an open-loop control mode, and when the stepping motor based on the open-loop control mode is used for providing power output for a tripod head of the camera, the phenomenon of step loss is easy to occur. For example, in order to track a moving target or switch between different targets, a short-time high-speed movement requirement exists, and the short-time high-speed movement generates instantaneous load increment on a stepping motor, and if the load increment is too large, the stepping motor is out of step, and the monitoring of the camera is out of position.

Therefore, how to avoid the step loss of the stepping motor becomes a technical problem to be solved in the prior art.

Disclosure of Invention

The technical scheme provided by the embodiment of the invention aims to avoid the step loss of the stepping motor.

In one embodiment, there is provided a drive control apparatus of a stepping motor, including:

the inverter driving module is used for generating driving power for the stepping motor;

the speed measurement sampling module is used for detecting phase voltage and phase current of the stepping motor from the inversion driving module;

the driving control module is used for determining the zero-crossing period of the back electromotive force of the stepping motor by using the detected phase voltage and phase current; determining the rotating speed of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor; and according to the rotating speed of the stepping motor, adjusting the driving power generated by the inversion driving module on the stepping motor, wherein:

when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, providing voltage compensation for the driving voltage of the inversion driving module so as to make up the power difference of the driving power compared with the load increment caused by the increase of the rotating speed;

and when the rotating speed is greater than a preset second high-speed threshold, providing current compensation for the driving current of the inversion driving module on the basis of voltage compensation so as to make up the power difference of the driving power based on the voltage compensation compared with the load increment.

Optionally, the inverter driving module further comprises a voltage adjusting module, and the driving control module further generates a voltage compensation signal to the voltage adjusting module, wherein the voltage compensation signal is used for driving the voltage adjusting module to increase the voltage value of the driving voltage provided for the inverter driving module to a compensation voltage value larger than the rated voltage value.

Optionally, the driving control module further generates a PWM signal with a compensation duty ratio to the inverter driving module during the period of generating the voltage compensation signal, where the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to a preset second high-speed threshold, so as to increase the turn-on amplitude of the on-state switch of each phase of bridge arm in the inverter driving module.

Optionally, the inverter driving module further comprises a PWM driving module, and the driving control module further generates a current compensation signal to the PWM driving module in a period of generating the voltage compensation signal, where the current compensation signal is used to control the PWM driving module to generate a PWM signal with a compensation duty ratio to the inverter driving module, and the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to a preset second high-speed threshold, so as to increase the turn-on amplitude of the on-state switch of each phase of bridge arm in the inverter driving module.

Optionally, the driving control module is further configured to adjust the driving voltage of the inverter driving module to be less than a rated voltage value when the rotation speed is less than a preset low-speed threshold value, so as to reduce power consumption of the stepping motor.

Optionally, the power supply further comprises a voltage regulation module, wherein the voltage regulation module comprises a first power supply and a second power supply which are alternatively enabled: when the rotating speed is greater than or equal to a preset low-speed threshold and less than or equal to a preset first high-speed threshold, the driving control module generates a first power supply selection signal to the voltage regulation module, wherein the first power supply selection signal is used for starting a first power supply to provide driving voltage with a voltage value of a rated voltage value for the inversion driving module; when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, the driving control module generates a first power supply selection signal and a voltage compensation signal to the voltage regulation module, wherein the voltage compensation signal is used for driving the first power supply to increase the voltage value of the driving voltage provided for the inversion driving module to a compensation voltage value greater than a rated voltage value; when the rotating speed is smaller than the preset low-speed threshold value, the driving control module further generates a second power supply selection signal to the voltage regulating module, and the driving voltage of the inversion driving module is regulated to be smaller than the rated voltage value when the rotating speed falls within the preset first high-speed threshold value, wherein the second power supply selection signal is used for starting a second power supply to provide the driving voltage with the voltage value smaller than the rated voltage value for the inversion driving module.

In another embodiment, there is provided a driving control method of a stepping motor, including:

determining a zero-crossing period of a back electromotive force of the stepping motor by using the phase voltage and the phase current of the stepping motor detected from the inverter driving module;

determining the rotating speed of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor;

according to step motor's rotational speed, adjust the drive power that contravariant drive module produced step motor, wherein:

when the rotating speed is greater than a preset first high-speed threshold and less than or equal to a preset second high-speed threshold, providing voltage compensation for the driving voltage of the inversion driving module so as to make up the power difference of the driving power compared with the load increment caused by the increase of the rotating speed;

when the rotating speed is greater than a preset first high-speed threshold and exceeds a preset second high-speed threshold, current compensation is provided for the driving current of the inversion driving module on the basis of voltage compensation, so that the power difference of the driving power based on the voltage compensation compared with the load increment is made up.

Optionally, providing voltage compensation for the driving voltage of the inverter driving module includes: and generating a voltage compensation signal to the voltage regulation module, wherein the voltage compensation signal is used for driving the voltage regulation module to increase the voltage value of the driving voltage provided for the inversion driving module to a compensation voltage value larger than the rated voltage value.

Optionally, providing current compensation for the driving current of the inverter driving module on the basis of the voltage compensation includes: and in the period of generating the voltage compensation signal, generating a PWM signal with a compensation duty ratio to the inversion driving module, wherein the compensation duty ratio of the PWM signal is greater than the rated duty ratio of the PWM signal when the rotating speed is less than or equal to a preset second high-speed threshold value, so as to improve the opening amplitude of the conducting switch of each phase of bridge arm in the inversion driving module.

Optionally, providing current compensation for the driving current of the inverter driving module on the basis of voltage compensation includes: and generating a current compensation driving signal to the PWM driving module in a period of keeping generating a voltage compensation signal to the voltage regulating module, wherein the current compensation driving signal is used for controlling the PWM driving module to generate a PWM signal with a compensation duty ratio to the inversion driving module, and the compensation duty ratio of the PWM signal is larger than a rated duty ratio of the PWM signal when the rotating speed is less than or equal to a preset second high-speed threshold value, so as to improve the opening amplitude of a conducting switch of each phase of bridge arm in the inversion driving module.

Optionally, the adjusting the driving power generated by the inverter driving module to the stepping motor according to the rotation speed of the stepping motor further includes: when the rotating speed is smaller than the preset first high-speed threshold value, the voltage value of the driving voltage of the inversion driving module is adjusted to be smaller than the rated voltage value, so that the power consumption of the stepping motor is reduced.

Optionally, providing voltage compensation for the driving voltage of the inverter driving module includes: generating a first power selection signal and a voltage compensation signal to a voltage regulation module, wherein the first power selection signal is used for starting a first power supply which is used for providing a rated voltage value of a driving voltage in the voltage regulation module, and the voltage compensation signal is used for driving the first power supply to increase the voltage value of the driving voltage provided for an inversion driving module to a compensation voltage value which is greater than the rated voltage value; the voltage value of the driving voltage of the inversion driving module is adjusted to be smaller than the rated voltage value so as to reduce the power consumption of the stepping motor, and the method comprises the following steps: and generating a second power supply selection signal to the voltage regulation module, wherein the second power supply selection signal is used for enabling a second power supply in the voltage regulation module to provide a driving voltage with a voltage value smaller than the rated voltage value for the inversion driving module.

Based on the above embodiment, the detected phase voltage and phase current of the stepping motor can be used to determine the back electromotive force of the stepping motor, and the rotation speed of the stepping motor can be determined according to the back electromotive force of the stepping motor, thereby realizing non-inductive observation of the stepping motor; according to the rotating speed determined in a non-inductive observation mode, the driving power generated by the inverter driving module on the stepping motor can be adjusted, so that the driving power can be adaptively changed along with the load change matched with the rotating speed through voltage compensation or the combination of the voltage compensation and the current compensation, and the stepping motor is prevented from being out of step. Furthermore, depending on the rotational speed determined in a sensorless manner, it is also possible to switch to a lower drive power when the rotational speed is too low in order to reduce the power consumption of the stepper motor.

Drawings

The following drawings are only schematic illustrations and explanations of the present invention, and do not limit the scope of the present invention:

FIG. 1 is a schematic diagram of a drive control apparatus of a stepping motor in one embodiment;

FIG. 2 is a schematic diagram of an exemplary configuration of the drive control apparatus shown in FIG. 1 for implementing phase voltage and phase current detection;

fig. 3 is a schematic diagram of a signal waveform based on the back electromotive force determined as in the example shown in fig. 2;

FIG. 4 is a schematic structural diagram of an example of the driving control apparatus shown in FIG. 1 for implementing voltage compensation;

FIGS. 5a and 5b are schematic structural diagrams of an example of the current compensation of the driving control device shown in FIG. 1;

FIG. 6 is an expanded schematic view of the drive control apparatus shown in FIG. 1 and FIG. 1;

FIG. 7 is a schematic diagram of an example structure based on the extended principle shown in FIG. 6;

fig. 8 is a flowchart illustrating a driving control method of a stepping motor in another embodiment;

fig. 9 is an expanded flow diagram of the driving control method shown in fig. 8.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.

Fig. 1 is a schematic diagram of a drive control device of a stepping motor in one embodiment. Referring to fig. 1, in this embodiment, the driving control device of the stepping motor may include:

an inverter driving module 10 for generating a driving power for the stepping motor 90;

the speed measurement sampling module 20 is used for detecting phase voltage and phase current of the stepping motor 90 from the inverter driving module 10;

a driving control module 30 for determining a zero-crossing period of a back electromotive force of the stepping motor 90 using the phase voltage and the phase current of the stepping motor 90 detected from the inverter driving module 10; determining the rotation speed omega _ det of the stepping motor 90 according to the zero-crossing period of the back electromotive force of the stepping motor 90; and adjusting the driving power generated by the inverter driving module 10 to the stepping motor 90 according to the rotation speed ω _ det of the stepping motor 90, wherein:

when the rotation speed ω _ det is greater than the preset first high-speed threshold ω _ mid and less than or equal to the preset second high-speed threshold ω _ high, it indicates that the load matched with the current rotation speed ω _ det exceeds the load range sufficient for the rated power to bear and is less than or equal to the load limit for enabling the inverter driving module 10 to generate the driving power with the inverter efficiency not less than the preset efficiency threshold, so that the driving voltage V _ drv of the inverter driving module 10 may be provided with the voltage compensation Δ V (constant voltage driving) to compensate the power difference of the load increment caused by the increase of the driving power compared with the rotation speed ω _ det;

when the rotation speed ω _ det is greater than the preset second high speed threshold ω _ high, it indicates that the load matching the current rotation speed ω _ det exceeds the load limit that causes the inverter driving module 10 to generate the driving power with the inverter efficiency not lower than the preset efficiency threshold, and therefore, the driving current I _ drv of the inverter driving module 10 may be provided with the current compensation Δ I (constant current driving) on the basis of the voltage compensation Δ V to compensate for the power difference of the driving power based on the voltage compensation Δ V compared to the load increment.

Based on the above-described drive control device, the back electromotive force of the stepping motor can be determined using the detected phase voltage and phase current of the stepping motor 90, and the rotation speed ω _ det of the stepping motor 90 can be determined from the back electromotive force of the stepping motor 90, thereby achieving non-inductive observation of the stepping motor 90; according to the rotation speed ω _ det determined in a non-inductive observation manner, the driving power generated by the inverter driving module 10 for the stepping motor 90 can be adjusted, so that the driving power can be adaptively changed following the load change matched with the rotation speed ω _ det through the voltage compensation Δ V or the combination of the voltage compensation Δ V and the current compensation Δ I, and the stepping motor 90 is prevented from being out of step. Furthermore, when this stepping motor 90 is used to drive the pan/tilt head of a camera, by avoiding the stepping motor 90 from being out of step, the monitoring of the camera can be prevented from being out of position.

Compared with the scheme of avoiding the camera monitor dislocation by adopting the servo direct current motor based on the closed loop control mode, the use of the stepping motor 90 driven by the drive control device can reduce the hardware cost and improve the reliability because:

1. if a servo dc motor based on a closed-loop control method is used, external monitoring elements such as an angle encoder or a hall sensor are required to be introduced in order to provide closed-loop feedback, and the use of the stepping motor 90 driven by the above-described drive control device may eliminate the need for the use of these external monitoring elements;

2. if a servo direct current motor based on a closed loop control mode is used, in order to ensure the driving precision of the servo direct current motor, a high-precision transmission mechanism such as a gear reduction box needs to be introduced, and the stepping motor 90 driven by the driving control device does not need to additionally use the high-precision transmission mechanism;

3. if a servo dc motor based on a closed-loop control method is used, in order to run a servo control algorithm which is more complicated than the control logic of the stepping motor, a high-performance processing device such as a DSP (Digital Signal Processor) is required, and the drive control module 30 in the above-described drive control device may be implemented by an MCU (micro control Unit), for example, the drive control module 30 may be an MCU of the model STM 32.

That is, the above-described drive control device for driving the stepping motor 90 does not need to introduce an external monitoring element and a high-precision transmission mechanism, which are easily damaged and costly, or need not necessarily use a high-performance processing device such as a DSP, and thus can reduce hardware costs and improve reliability compared to a scheme based on a servo dc motor of a closed-loop control system.

In addition, the stepping motor 90 in this embodiment may be a two-phase stepping motor, or may be a three-phase stepping motor. The stepping motor 90 is preferably a three-phase stepping motor because of a smaller stepping angle, a smaller low-speed resonance region, lower noise, and higher stability of the three-phase stepping motor compared to the two-phase stepping motor.

Fig. 2 is a schematic diagram of an example structure of the drive control apparatus shown in fig. 1 for detecting phase voltage and phase current. Referring to fig. 2, taking the stepping motor 90 as a three-phase stepping motor as an example, the inverter driving module 10 may include a three-phase H-bridge circuit, and the speed measurement sampling module 20 may include:

a phase voltage sampling circuit 21, configured to collect phase voltages (voltage values of terminal voltages of the legs with respect to ground) from each phase leg of the inverter driving module 10, for example, the phase voltage sampling circuit 21 may include differential amplifiers 21a, 21b, and 21c respectively connected to each phase leg, and each of the differential amplifiers 21a, 21b, and 21c may output the sampled phase voltages of the corresponding phase to an ADC (Analog to Digital Converter) 31 integrated in the driving control module 30;

the phase current detection circuit 22 is configured to perform zero-crossing detection on the phase current of each phase arm of the inverter driving module 10, for example, the phase current sampling circuit 22 may include zero-crossing detection circuits 22a, 22b, and 22c respectively connected to each phase arm, and each of the zero-crossing detection circuits 22a, 22b, and 22c may output a zero-crossing detection signal of the phase current of the corresponding phase to a GPIO (General-purpose-input/output) interface integrated in the driving control module 30.

In addition, the on-switches of the respective phase arms in the inverter driving module 10 are usually semiconductor devices such as MOS (Metal oxide semiconductor) transistors, which are prone to generate peak voltages when switching on and off, and in order to reduce the influence of the peak voltages generated by the on-switches of the respective phase arms in the inverter driving module 10 on the detected phase voltages, the speed measurement sampling circuit 20 may further include a filter circuit 23, for example, an RC low-pass filter circuit, between the phase voltage sampling circuit 21 and the drive control module 30.

Fig. 3 is a signal waveform diagram based on the back electromotive force determined as an example shown in fig. 2. Referring to fig. 3, based on the voltage value of the phase voltage and the zero-crossing detection signal of the phase current collected in the example shown in fig. 2, the driving control module 30 (the control core 33 therein) may determine the back electromotive forces Ea, Eb, Ec of each phase by using the phase voltage of each phase detected during the period when the phase current of each phase is zero and the preset motor parameters, and determine the zero-crossing period of the back electromotive force of the stepping motor according to the zero-point distribution of the back electromotive forces Ea, Eb, Ec of each phase (the zero-crossing detection signal of the back electromotive force is represented by the rising edge of the square wave pulse in fig. 3).

The motor parameters used for determining the counter electromotive force may include the number of pole pairs N of the stepping motor 90, a counter electromotive force constant K, a phase resistance R and a phase inductance L of the stator coil, and the like. Since this embodiment does not limit the determination manner of determining the back electromotive force, a detailed description of an algorithm for determining the back electromotive force is not given here.

It can be understood that, for the two-phase stepping motor, the difference mainly lies in the change of the number of the bridge arms in the inverter driving module 10, but the detection manner of the phase voltage and the phase current, and the determination of the back electromotive force and the rotation speed can adopt the same principle as the three-phase stepping motor.

Fig. 4 is a schematic structural diagram of an example of implementing voltage compensation by the driving control device shown in fig. 1. Referring to fig. 4, the driving control apparatus in this embodiment may further include a voltage adjusting module 40, wherein:

when the rotation speed ω _ det is greater than the preset first high speed threshold ω _ mid and less than or equal to the preset second high speed threshold ω _ high, the driving control module 30 may generate the voltage compensation signal Sig _ Vcomp to the voltage regulating module 40 to provide the voltage compensation Δ V for the driving voltage V _ drv of the inverter driving module 10, that is, the voltage compensation signal Sig _ Vcomp is used for the driving voltage regulating module 40 to increase the voltage value of the driving voltage V _ drv provided for the inverter driving module 10 to a compensation voltage value (sum of V _ drv and Δ V) greater than the rated voltage value, for example, by enabling the reference voltage of the reference voltage terminal V _ ref of the voltage regulating module 40, and the driving voltage V _ drv generated by the voltage output terminal Vout for the voltage regulating module 40 is increased to the compensation voltage value of the sum of V _ drv and Δ V.

Fig. 5a and 5b are schematic structural diagrams of an example of the current compensation of the driving control device shown in fig. 1. In the example shown in fig. 5a and 5b, the current compensation may be achieved by adjusting the duty cycle of a PWM (Pulse Width Modulation) signal to the inverter driving module 10.

Referring to fig. 5a, if a DAC (Digital to Analog Converter) 34 is integrated in the driving control module 30, when the rotation speed ω _ det is greater than the preset second high-speed threshold ω _ high, the driving control module 30 (the control core 33) may generate a PWM signal having a compensation duty ratio to the inverter driving module 10 during the period of generating the voltage compensation signal Sig _ Vcomp, where the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to the preset second high-speed threshold ω _ high, the compensation duty ratio may be a sum of the rated duty ratio and a duty compensation amount Δ PW, for example, the rated duty ratio may be 50%, the duty compensation amount Δ PW may be between 1% and 30%, and the obtained compensation duty ratio may be between 31% and 80%, so as to increase the opening amplitude of the bridge arm switches (e.g., MOS transistors) that are conducted in each phase of the inverter driving module 10, therefore, the current compensation delta I can be provided for the driving current I _ drv of the inversion driving module on the basis of the voltage compensation delta V.

Referring to fig. 5b again, if the driving control apparatus further includes a PWM driving module 50 (which may be in serial communication with the driving control module 10), the driving control module 10 may not need an internal DAC or use an internal DAC, and when the rotation speed ω _ det is greater than the preset second high-speed threshold ω _ high, the driving control module 10 may generate a current compensation signal Sig _ Icomp to the PWM driving module 50 during a period of generating the voltage compensation signal Sig _ Vcomp, where the current compensation driving signal is used to control the PWM driving module 50 to generate a PWM signal with a compensation duty ratio to the inverter driving module 10, and the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to the preset second high-speed threshold ω _ high, so as to increase an opening amplitude of the on-off switch of each phase bridge arm in the inverter driving module 10, therefore, the current compensation Δ I can be provided for the driving current I _ drv of the inverter driving module 10 on the basis of the voltage compensation Δ V.

The PWM driving module 50 shown in fig. 5b may be a DAC chip, for example, a TVL (TI Low Value, texas instruments) DAC chip produced by TI (texas instruments), and the DAC chip may be configured with a reasonable reference voltage to provide a switching voltage sufficient to open the conducting switches of the legs of each phase in the inverter driving module 10.

Fig. 6 is an expanded schematic diagram of the drive control device shown in fig. 1 and fig. 1. Referring to fig. 6, the driving control module 30 may be further configured to adjust the driving voltage V _ drv of the inverter driving module 10 to a low voltage value V _ low (the low voltage value V _ low is smaller than a rated voltage value of the driving voltage when the rotation speed ω _ det falls within the speed interval [ ω _ low, ω _ mid ]) when the rotation speed ω _ det is smaller than the preset low speed threshold ω _ low, for example, when the stepping motor 90 stops operating or slowly rotates at a relatively low rotation speed, so as to reduce the power consumption of the stepping motor 90.

When the rotation speed ω _ det is greater than the preset first high speed threshold ω _ mid, reference may be made to the manner shown in fig. 4, which is not described herein again.

Fig. 7 is a schematic diagram of an example structure based on the expansion principle shown in fig. 6. Referring to fig. 7, in this embodiment, the driving control apparatus may further include a voltage adjusting module 60, wherein the voltage adjusting module 60 includes a first power source 61 and a second power source 62 that are alternatively enabled.

When the rotation speed ω _ det falls within the speed interval [ ω _ low, ω _ mid ], the driving control module 30 may generate a first power source selection signal (Sel _ V in the first level state) to the voltage regulating module 60, wherein the first power source selection signal (Sel _ V in the first level state) is used for enabling the first power source 61 in the voltage regulating module 60, so that the first power source 61 provides the driving voltage V _ drv with the voltage value as the rated voltage value to the inverter driving module 10 in response to the first power source selection signal (Sel _ V in the first level state) when the rotation speed ω _ det falls within the speed interval [ ω _ low, ω _ mid ]. For example, the first power supply selection signal (Sel _ V in the first level state) may set the enable terminal En of the first power supply 61 to be active.

When the rotation speed ω _ det is greater than the preset first high speed threshold ω _ mid, the driving control module 30 may generate a first power selection signal (Sel _ V is in the first level state) and a voltage compensation signal Sig _ Vcomp to the voltage adjusting module 60, where the voltage compensation signal Sig _ Vcomp is used for driving the first power supply 61 to increase the voltage value of the driving voltage V _ drv provided for the inverter driving module 10 to a compensation voltage value (sum of V _ drv and Δ V) greater than the rated voltage value, so as to provide the voltage compensation Δ V for the driving voltage of the inverter driving module 10;

when the rotation speed ω _ det is smaller than the preset low speed threshold ω _ low, the driving control module 30 may generate a second power source selection signal (Sel _ V is in the second level state) to the voltage regulating module 60, wherein the second power source selection signal (Sel _ V is in the second level state) is used for enabling the second power source 62 in the voltage regulating module 60 to provide the driving voltage with a voltage value smaller than the rated voltage value for the inverter driving module 10, so as to regulate the voltage value of the driving voltage V _ drv of the inverter driving module 10 to be a low voltage value V _ low smaller than the rated voltage value when the rotation speed falls within the speed interval [ ω _ low, ω _ mid ].

The above description has been given only by taking the example that the drive control device drives one stepping motor, and it can be understood that, for at least two stepping motors in a video camera having a multi-degree-of-freedom pan/tilt head, such as a ball camera, the number of the inverter drive modules 10 and the velocity measurement sampling modules 20 equal to the number of the stepping motors may be arranged in the drive control device, and in addition, the voltage adjustment module 40 or 60 may be arranged independently for each stepping motor or shared by at least two stepping motors according to the voltage value requirement of the drive voltage. If there are sufficient DAC resources in the drive control module 30, the PWM drive module 50 may not be needed, and if the drive control module 30 does not have sufficient DAC resources to allocate to at least two stepper motors, the PWM drive module 50 may be configured in an amount equal to, or slightly less than, the number of stepper motors.

In addition to the above-described drive control apparatus, the following embodiments also provide a drive control method that can be executed by any processing device that can be used as a drive control module.

Fig. 8 is a flowchart illustrating a driving control method of the stepping motor in another embodiment. Referring to fig. 8, in this embodiment, the driving control method of the stepping motor may include:

s810: and determining a zero-crossing period of the back electromotive force of the stepping motor by using the phase voltage and the phase current of the stepping motor detected from the inverter driving module.

For example, the back electromotive force of each phase is determined by using the phase voltage of each phase detected during the period in which the phase current of each phase is zero and a preset motor parameter; then, the zero-cross period of the back electromotive force of the stepping motor is determined based on the zero-point distribution of the back electromotive force of each phase.

S830: determining the rotating speed omega _ det of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor, and determining the regulating strategy of the inverter driving module for the driving power generated by the stepping motor according to the rotating speed omega _ det of the stepping motor, wherein:

if the rotation speed is greater than the preset first high speed threshold value ω _ mid and less than or equal to the preset second high speed threshold value ω _ high, it indicates that the load matched with the current rotation speed ω _ det has exceeded the load range sufficient for the rated power to bear and is less than or equal to the load limit for enabling the inverter driving module to generate the driving power with the inverter efficiency not less than the preset efficiency threshold value, and therefore, the operation may jump to S851;

if the rotating speed is greater than the preset second high-speed threshold ω _ high, it indicates that the load matched with the current rotating speed ω _ det exceeds the load limit for enabling the inverter driving module to generate the driving power with the inverter efficiency not less than the preset efficiency threshold, and therefore, the operation can be skipped to S853;

otherwise, the driving power may not be compensated, and then the present flow ends.

S851: when the rotation speed ω _ det is greater than the preset first high-speed threshold ω _ mid and less than or equal to the preset second high-speed threshold ω _ high, voltage compensation (constant voltage driving) is provided for the driving voltage of the inverter driving module to make up for a power difference of a load increment caused by the increase of the driving power compared with the rotation speed ω _ det.

For example, a voltage compensation signal may be generated to the voltage regulation module, wherein the voltage compensation signal is used to drive the voltage regulation module to boost a voltage value of the driving voltage provided for the inverter driving module to a compensation voltage value greater than a rated voltage value.

S853: when the rotation speed ω _ det is greater than a preset second high-speed threshold ω _ high, current compensation (constant current drive) is provided for the driving current of the inverter driving module on the basis of the voltage compensation so as to make up for a power difference of the driving power based on the voltage compensation compared with a load increment.

For example, during the period of generating the voltage compensation signal, a PWM signal with a compensation duty ratio may be generated to the inverter driving module, where the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to the preset second high-speed threshold ω _ high, so as to increase the turn-on amplitude of the on-switches of the bridge arms of each phase in the inverter driving module.

Or, a current compensation driving signal may be generated to the PWM driving module during a period of generating the voltage compensation signal, where the current compensation driving signal is used to control the PWM driving module to generate a PWM signal with a compensation duty ratio to the inverter driving module, and the compensation duty ratio of the PWM signal is greater than a rated duty ratio of the PWM signal when the rotation speed is less than or equal to the preset second high-speed threshold ω _ high, so as to increase the turn-on amplitude of the on-state switch of each phase of the bridge arm in the inverter driving module.

Based on the above process, the detected phase voltage and phase current of the stepping motor can be used to determine the back electromotive force of the stepping motor, and the rotation speed ω _ det of the stepping motor can be determined according to the back electromotive force of the stepping motor, thereby realizing non-inductive observation of the stepping motor; according to the rotation speed omega _ det determined in a non-inductive observation mode, the driving power generated by the inverter driving module for the stepping motor can be adjusted, so that the driving power can be adaptively changed along with the load change matched with the rotation speed omega _ det through voltage compensation or the combination of the voltage compensation and the current compensation, and the step loss of the stepping motor is avoided. Furthermore, when the stepping motor is used to drive the pan/tilt head of a camera, the monitoring of the camera can be prevented from being out of position by preventing the stepping motor from being out of step.

Fig. 9 is an expanded flow diagram of the driving control method shown in fig. 8. Referring to fig. 9, the driving control method in this embodiment may be further expanded to include:

s910: and determining a zero-crossing period of the back electromotive force of the stepping motor by using the phase voltage and the phase current of the stepping motor detected from the inverter driving module. Here, this step may be substantially the same as S810 shown in fig. 8, and is not described here again.

S930: determining the rotating speed omega _ det of the stepping motor according to the zero-crossing period of the back electromotive force of the stepping motor, and determining the regulating strategy of the inverter driving module for the driving power generated by the stepping motor according to the rotating speed omega _ det of the stepping motor, wherein:

if the rotation speed is greater than the preset first high speed threshold value ω _ mid and less than or equal to the preset second high speed threshold value ω _ high, it indicates that the load matched with the current rotation speed ω _ det has exceeded the load range sufficient for the rated power to bear and is less than or equal to the load limit for enabling the inverter driving module to generate the driving power with the inverter efficiency not less than the preset efficiency threshold value, and therefore, the operation may jump to S951;

if the rotating speed is greater than the preset second high-speed threshold ω _ high, it indicates that the load matched with the current rotating speed ω _ det exceeds the load limit for enabling the inverter driving module to generate the driving power with the inverter efficiency not less than the preset efficiency threshold, and therefore, the operation can be skipped to S953;

if the rotation speed ω _ det is less than the preset low-speed threshold ω _ low, it indicates that the stepping motor is currently stopped or slowly rotates at a relatively low rotation speed, and therefore, the step may jump to S955;

otherwise, i.e. the rotation speed falls within the speed interval [ ω _ low, ω _ mid ], no compensation and power reduction measures may be taken for the driving power, e.g. keeping only the first power selection signal to the voltage regulation module, and then ending the present procedure.

S951: when the rotation speed ω _ det is greater than the preset first high-speed threshold ω _ mid and less than or equal to the preset second high-speed threshold ω _ high, voltage compensation (constant voltage driving) is provided for the driving voltage of the inverter driving module to make up for a power difference of a load increment caused by the increase of the driving power compared with the rotation speed ω _ det.

For example, a first power selection signal and a voltage compensation signal may be generated to the voltage regulation module, wherein the first power selection signal is used to enable a first power supply in the voltage regulation module for providing a rated voltage value of the driving voltage, and the voltage compensation signal is used to drive the first power supply to boost the voltage value of the driving voltage provided for the inverter driving module to a compensation voltage value greater than the rated voltage value.

S953: when the rotation speed ω _ det is greater than a preset second high-speed threshold ω _ high, current compensation (constant current drive) is provided for the driving current of the inverter driving module on the basis of voltage compensation so as to make up for a power difference of a compensation quota for driving voltage compensation compared with a load increment.

This step may be substantially the same as S853 shown in fig. 8, and will not be described herein.

S955: when the rotating speed omega _ det is smaller than the preset low-speed threshold omega _ low, the voltage value of the driving voltage of the inversion driving module is adjusted to be smaller than the rated voltage value, so that the power consumption of the stepping motor is reduced.

For example, a second power source selection signal may be generated to the voltage regulation module, where the second power source selection signal is used to enable a second power source in the voltage regulation module to provide a driving voltage with a voltage value smaller than the rated voltage value for the inverter driving module.

Based on the above-described flow, it is possible to further reduce the power consumption of the stepping motor by switching to a lower driving power when the rotation speed is too low, on the basis of the technical effect produced by the flow shown in fig. 8.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.