A current commutation control method for a high-speed stepping motor applied to a space environment

Abstract

The application relates to a high-speed stepping motor current commutation control method applied to a space environment. The high-speed stepping motor current commutation control adopts a control method combining fast discharge and slow discharge, a high-speed parallel control signal of a high-speed stepping motor driving circuit is generated through a reverse fuse FPGA device to control the bridge circuit MOSFET switch logic state, and the winding current of the stepping motor during high-speed movement is rapidly diverted. The application reduces power consumption, improves system efficiency and system reliability under the premise of ensuring high-speed operation of the stepping motor in the space environment, simultaneously, the proportion of the fast discharge time to the total discharge time can be changed according to the load, and the requirement of high-speed motor current fast discharge is more easily met. The control mode can be changed on the basis of the original control hardware, the universality is good, and the application has the advantages of high reliability and easy realization.

Description

Technical Field

[0001] This invention relates to the field of space mechanism drive control, and in particular to a method for controlling the current commutation of a high-speed stepper motor in a space environment. Background Technology

[0002] A stepper motor is an electromechanical device that directly converts electrical pulses into mechanical motion. It boasts advantages such as high precision, fast response, and smooth movement, and is widely used in the drive systems of spacecraft. In spacecraft, high-speed stepper motors are primarily used to control and drive the rotation, turning, and movement of various mechanisms, such as the deployment of solar panels, the positioning of satellite antennas, and the positioning of telescopes. To achieve torque amplification, miniaturized motors often employ high reduction ratios, requiring high-speed motor movement. To meet the demands of rapid response and lightweight applications, the need for high-speed stepper motor drives is constantly increasing.

[0003] Currently, most stepper motors used in space applications operate in low-speed mode. Drive circuits for low-speed operation typically employ a slow discharge mode. Slow discharge results in a slower current commutation speed. Directly using this drive method and adjusting parameters to drive the stepper motor at high speed often causes the motor to fail to start or stop during startup due to step loss, thus failing to increase the motor's operating speed. A few high-speed stepper motors used in space applications employ a fast discharge mode. Fast discharge accelerates the current commutation speed, thereby increasing the motor speed. However, this leads to numerous glitches in the current waveform, increasing torque ripple and affecting the smooth operation of the motor.

[0004] Since both methods have significant drawbacks, it is necessary to study the current commutation method of high-speed stepper motors for space mechanisms, taking into account current space mechanism drive technology. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a high-speed stepper motor current commutation control method applicable to space environments. This method is flexible, simple to control, and easy to implement. It modifies the control method based on existing control hardware, has good versatility, and boasts advantages such as high reliability and ease of implementation. It can be well applied to the high-speed motion control of stepper motors in high-reliability, long-life space mechanisms.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides a high-speed stepper motor current commutation control method applied in a space environment. The high-speed stepper motor current commutation control employs a combination of fast and slow discharge control methods. A control signal for the high-speed stepper motor drive circuit is generated by an anti-fuse FPGA device to control the switching logic state of the MOSFETs in the bridge circuit, enabling rapid current reversal during high-speed stepper motor movement. The proportion of fast discharge time to total discharge time is adjusted according to the load, thereby meeting the requirements for rapid current discharge of the high-speed motor while reducing torque ripple during motor operation.

[0008] Specifically, the high-speed stepper motor drive circuit includes two independent H-bridge circuits; each H-bridge circuit is composed of four N-channel MOSFETs with high-speed switching effect, and the N-channel MOSFETs have the same model and specifications.

[0009] Specifically, the high-speed stepper motor is driven by the antifuse FPGA device using high-frequency chopping to control the H-bridge circuit, and a dead time is set to avoid short circuit to ground caused by shoot-through of the same side bridge arm.

[0010] Specifically, the high-speed stepper motor control circuit uses the antifuse FPGA device to generate the control signal of the stepper motor drive circuit. The process characteristics of the antifuse FPGA ensure that there is no single-event upset in the on-orbit working environment, generating an H-bridge circuit control signal, which is amplified and directly drives the N-channel MOSFET device to turn on and off. Each N-channel MOSFET corresponds to one signal, and each MOSFET control signal is completely independent, realizing high-speed parallel output of the control signal.

[0011] Specifically, the antifuse FPGA device uses a 46KHz high-frequency chopping signal to quickly adjust the winding current by adjusting the switching on ratio of 10% to 90% within each switching cycle.

[0012] Specifically, the four N-channel MOSFETs in each H-bridge circuit are divided into an upper left bridge arm, a lower left bridge arm, an upper right bridge arm, and a lower right bridge arm. When the upper and lower bridge arms on the same side alternately turn on, a dead time of 1 to 5 μs is set between the alternation of the upper and lower bridge arms.

[0013] Specifically, when the winding current is in the positive increasing phase, the upper left bridge arm and the lower right bridge arm are opened simultaneously to achieve positive current transmission; when the winding current needs to be discharged quickly during commutation, the upper right bridge arm is opened, and the winding holding current is charged to the power supply in reverse through the upper right bridge arm, causing the current to drop rapidly; when the current commutation switches to slow discharge, the upper left and upper right bridge arms are closed, and the lower left and lower right bridge arms are opened, and the winding holding current is attenuated through the lower left and lower right bridge arms, causing the current to drop slowly.

[0014] Specifically, by adjusting the proportion of rapid discharge time to total discharge time according to the load, the requirements for rapid current discharge of high-speed motors can be met while reducing torque ripple during motor operation.

[0015]

[0016]

[0017]

[0018] Where θ is the step angle of the stepper motor, which is a fixed value, and R is the impedance of the motor windings. The maximum value of the motor winding current is L, and the inductive reactance of the motor winding is L. The period of change of the motor winding current. The slow discharge time is half a current cycle. This is the rapid discharge time of half a current cycle.

[0019] The period T of the motor winding current change is directly proportional to the motor rotation speed V, V=(4×θ) / T. Therefore, the higher the motor rotation speed V is required, the smaller the period T of the motor winding current change.

[0020] The proportion of rapid discharge time to total discharge time is adjusted according to the load change; the slow discharge time is calculated as follows: After calculation, the rapid discharge time is obtained by subtracting the slow discharge time from half a current change cycle. This achieves the requirement of rapid current discharge for high-speed motors while reducing torque pulsation during motor operation.

[0021] Compared with the prior art, the present invention has at least one of the following technical advantages:

[0022] The high-speed stepper motor current commutation control method of this invention adopts a discrete architecture in the drive control circuit, achieving good heat dissipation. The use of aerospace-grade antifuse can well meet the space environment. In terms of control method, it adopts a combination of fast discharge and slow discharge. Through reasonable switching logic and high-frequency drive waveform, it realizes the rapid commutation of motor winding current, thereby ensuring the high-speed movement of stepper motor. It can also change the proportion of fast discharge time to total discharge time according to the load, so as to meet the requirements of rapid current discharge of high-speed motor while reducing the torque ripple of motor operation. At the same time, by setting dead time, it ensures reliable safety during high-speed movement. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention.

[0024] Figure 1 This is a schematic diagram illustrating the principle and control logic of a high-speed stepper motor current commutation control method applied in a space environment, provided by an embodiment of the present invention.

[0025] Figure 2 This is a circuit block diagram of a high-speed stepper motor current commutation control method applied in a space environment, provided by an embodiment of the present invention.

[0026] Figure 3 This is a current diagram illustrating a high-speed stepper motor current commutation control method applied in a space environment, provided by an embodiment of the present invention.

[0027] Figure Labels

[0028] Q1: Upper left bridge arm; Q2: Lower left bridge arm; Q3: Upper right bridge arm; Q4: Lower right bridge arm. Detailed Implementation

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0030] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0031] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a method for controlling the current commutation of a high-speed stepper motor applied in a space environment. The advantages and features of the present invention will become clearer from the following description and claims.

[0032] Example

[0033] This invention provides a high-speed stepper motor current commutation control method applicable to space environments. The high-speed stepper motor current commutation control employs a combination of fast and slow discharge methods. A high-speed parallel control signal is generated by an anti-fuse FPGA device to control the MOSFET switching logic state of the bridge circuit, achieving rapid current reversal of the windings during high-speed stepper motor movement. The proportion of fast discharge time to total discharge time is adjusted according to the load, thus meeting the requirements for rapid current discharge of the high-speed motor while reducing torque ripple during motor operation.

[0034] Specifically, see Figure 1 and Figure 2 The high-speed stepper motor control circuit uses an antifuse FPGA device to generate high-speed parallel control signals for the stepper motor drive circuit. After signal amplification, the control signals respectively complete the switching control of MOSFET devices in the H-bridge drive circuit of the stepper motor A winding and the H-bridge drive circuit of the motor B winding.

[0035] Specifically, due to the special nature of the working environment, it is necessary to consider the influence of the space environment, such as total radiation dose and single-event effect. Due to the process characteristics of the antifuse FPGA device, it will not have single-event upset effect. Therefore, the high-speed stepper motor control circuit adopts the antifuse FPGA device. The high-speed stepper motor is driven by the antifuse FPGA device using high-frequency chopping to control the H-bridge circuit. At the same time, a dead time is set to avoid short circuit to ground caused by the same side bridge arm shoot-through.

[0036] Specifically, each H-bridge circuit consists of four N-channel MOSFETs with high-speed switching effect. The N-channel MOSFETs have the same model and specifications, and each N-channel MOSFET corresponds to one signal. The control signal of each MOSFET is completely independent, realizing high-speed parallel output of control signals.

[0037] Specifically, the antifuse FPGA device uses a 46KHz high-frequency chopping signal to quickly adjust the winding current by adjusting the switching ratio of 10% to 90% within each switching cycle. To avoid short circuits to ground caused by direct connection of the same bridge arm, a dead time of 1 to 5us is set between the switching of the upper and lower bridge arms when the upper and lower bridge arms of the same side are switching on, ensuring reliable safety during high-speed operation.

[0038] Specifically, see Figure 1 Each H-bridge circuit contains four N-channel MOSFETs: upper left arm Q1, lower left arm Q2, upper right arm Q3, and lower right arm Q4. When the winding current is in the positive increasing phase, both upper left arm Q1 and lower right arm Q4 are turned on simultaneously to achieve positive current transmission. When the winding current needs to be discharged quickly during commutation, the upper right arm Q3 is turned on, and the winding holding current charges the power supply in reverse through the upper right arm Q3, causing the current to drop rapidly. When the current commutation switches to slow discharge, the upper left arm Q1 and upper right arm Q3 are turned off, and the lower left arm Q2 and lower right arm Q4 are turned on, causing the winding holding current to decay through the lower left arm Q2 and lower right arm Q4, resulting in a slow current decrease.

[0039] For details, please refer to Figure 3 By adjusting the proportion of rapid discharge time to total discharge time according to the load, the requirements for rapid current discharge of high-speed motors can be met while reducing torque ripple during motor operation.

[0040]

[0041]

[0042]

[0043] Where θ is the step angle of the stepper motor, which is a fixed value, and R is the impedance of the motor windings. The maximum value of the motor winding current is L, and the inductive reactance of the motor winding is L. The period of change of the motor winding current. The slow discharge time is half a current cycle. This is the rapid discharge time of half a current cycle.

[0044] The period of change of motor winding current T is directly proportional to the motor rotation speed V, V=(4×θ) / T. Therefore, the higher the required motor rotation speed V, the smaller the period of change of motor winding current T.

[0045] The proportion of rapid discharge time to total discharge time is adjusted according to the load change; the slow discharge time is calculated as follows: After calculation, the rapid discharge time is obtained by subtracting the slow discharge time from half a current change cycle. This achieves the requirement of rapid current discharge for high-speed motors while reducing torque pulsation during motor operation.

[0046] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for controlling the current commutation of a high-speed stepper motor in a space environment, characterized in that, The high-speed stepper motor current commutation control employs a combination of fast and slow discharge methods. Control signals for the high-speed stepper motor drive circuit are generated by an anti-fuse FPGA device, controlling the MOSFET switching logic state of the bridge circuit. When rapid discharge is required for winding current commutation, the control signal controls the MOSFET switching logic state of the bridge circuit, causing the winding holding current to charge the power supply in reverse, resulting in a rapid current decrease. When the current switches to slow discharge, the control signal controls the MOSFET switching logic state of the bridge circuit, causing the current to decrease slowly. This achieves rapid current reversal during high-speed stepper motor operation. The proportion of rapid discharge time to total discharge time is adjusted according to the load, thus meeting the rapid current discharge requirements of the high-speed motor while reducing torque ripple during motor operation. Where θ is the step angle of the stepper motor, which is a fixed value, and R is the impedance of the motor windings. Where L is the maximum value of the motor winding current, and L is the inductive reactance of the motor winding. The period of change of the motor winding current. The slow discharge time is half a current cycle. This is the rapid discharge time of half a current cycle. This refers to the motor's rotational speed.

2. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 1, characterized in that, The high-speed stepper motor drive circuit includes two independent H-bridge circuits; each H-bridge circuit consists of four N-channel MOSFETs with high-speed switching effect, and the N-channel MOSFETs have the same model and specifications.

3. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 2, characterized in that, The high-speed stepper motor is driven by the antifuse FPGA device using high-frequency chopping to control the H-bridge circuit, and a dead time is set to avoid short circuit to ground caused by shoot-through of the same side bridge arm.

4. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 3, characterized in that, The high-speed stepper motor control circuit uses the antifuse FPGA device to generate the control signal of the stepper motor drive circuit; each of the N-channel MOSFETs corresponds to one signal, realizing the high-speed parallel output of the control signal.

5. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 4, characterized in that, The antifuse FPGA device uses a 46KHz high-frequency chopping signal to quickly adjust the winding current by adjusting the switching on ratio of 10% to 90% within each switching cycle.

6. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 4, characterized in that, The four N-channel MOSFETs in each H-bridge circuit are divided into an upper left bridge arm, a lower left bridge arm, an upper right bridge arm, and a lower right bridge arm. When the upper and lower bridge arms on the same side alternately turn on, a dead time of 1 to 5 μs is set between the alternation of the upper and lower bridge arms.

7. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 6, characterized in that, When the winding current is in the positive increasing phase, the upper left bridge arm and the lower right bridge arm are opened simultaneously to achieve positive current transmission. When the winding current needs to be discharged quickly during commutation, the upper right bridge arm is opened, and the winding holding current charges the power supply in reverse through the upper right bridge arm, causing the current to drop rapidly. When the current commutation switches to slow discharge, the upper left and upper right bridge arms are closed, and the lower left and lower right bridge arms are opened, causing the winding holding current to decay through the lower left and lower right bridge arms, resulting in a slow current decrease.

8. The method for current commutation control of a high-speed stepper motor applied in a space environment according to claim 7, characterized in that, The period T of the motor winding current change is directly proportional to the motor rotation speed V, V=(4×θ) / T. Therefore, the higher the motor rotation speed V is required, the smaller the period T of the motor winding current change. The proportion of rapid discharge time to total discharge time is adjusted according to the load change; the slow discharge time is calculated as follows: After calculation, the rapid discharge time is obtained by subtracting the slow discharge time from half a current change cycle. This achieves the requirement of rapid current discharge for high-speed motors while reducing torque pulsation during motor operation.

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