Control system and control method of sewing machine head oil pump

Abstract

The invention discloses a control system and a control method for a machine head oil pump of a sewing machine, which are applied to the technical field of industrial sewing machines. The H-bridge circuit is respectively connected with the power supply module and the sewing machine head oil pump; the man-machine interaction module is used for sending an oil quantity control instruction; the controller is connected with the man-machine interaction module and the H-bridge circuit and used for determining the duty ratio corresponding to the oil outlet quantity carried in the oil outlet quantity control instruction according to the preset mapping relation between the duty ratio and the oil outlet quantity; and generating a PWM (Pulse Width Modulation) driving signal according to the determined duty ratio, and carrying out driving control on the H-bridge circuit through the PWM driving signal, so that the oil outlet quantity of the sewing machine head oil pump conforms to the oil outlet quantity control instruction. By means of the scheme, the oil pump of the machine head of the sewing machine can be effectively controlled, the oil outlet amount can be accurately adjusted, and the phenomenon of insufficient or excessive oil supply is not prone to occurring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial sewing machines, in particular to a control system and control method for a sewing machine head oil pump. BACKGROUND

[0002] In the garment industry production line, industrial sewing machines such as lockstitch machines and overlock machines need to be continuously operated for a long time. The needle bar, rotating shuttle, and feed dog of the machine head are lubricated by oil pumps. If the oil pump supply is insufficient, it will cause wear and tear between the parts due to friction, causing jamming, abnormal noise, and other faults. In severe cases, it can cause damage to the mechanical structure of the machine head. Excessive oil supply may cause oil leakage, which can cause a short circuit in the electrical module of the equipment, causing the control system to malfunction. The current control scheme for the sewing machine head oil pump uses a relay or a simple switch to control the start and stop of the oil pump motor, which can achieve the operation of the machine head oil supply / stop. Since this scheme can only achieve a one-dimensional control mode of "with or without oil supply", it is prone to insufficient or excessive oil supply, and has poor scene adaptability.

[0003] In summary, how to effectively control the sewing machine head oil pump and reduce the probability of insufficient or excessive oil supply is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0004] The purpose of the present application is to provide a control system and control method for a sewing machine head oil pump to effectively control the sewing machine head oil pump and reduce the probability of insufficient or excessive oil supply.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] In a first aspect, the present application provides a control system for a sewing machine head oil pump, comprising:

[0007] a power supply module for outputting electric energy;

[0008] an H-bridge circuit connected to the power supply module and the sewing machine head oil pump, respectively;

[0009] a human-computer interaction module for issuing an oil output control instruction;

[0010] a controller connected to the human-computer interaction module and the H-bridge circuit, respectively, for determining the duty cycle corresponding to the oil output carried in the oil output control instruction according to a preset mapping relationship between the duty cycle and the oil output; generating a PWM driving signal according to the determined duty cycle and driving the H-bridge circuit through the PWM driving signal, so that the oil output of the sewing machine head oil pump meets the oil output control instruction.

[0011] In an embodiment, further comprising:

[0012] a first driving circuit connected with the first bridge arm in the H-bridge circuit and the controller respectively, so that the controller drives the first bridge arm in the H-bridge circuit through the first driving circuit; and the first driving circuit is a driving circuit with a hardware interlocking structure, so as to prohibit the first upper bridge arm switch and the first lower bridge arm switch in the first bridge arm from being turned on at the same time through the hardware interlocking structure;

[0013] a second driving circuit connected with the second bridge arm in the H-bridge circuit and the controller respectively, so that the controller drives the second bridge arm in the H-bridge circuit through the second driving circuit; and the second driving circuit is a driving circuit with a hardware interlocking structure, so as to prohibit the second upper bridge arm switch and the second lower bridge arm switch in the second bridge arm from being turned on at the same time through the hardware interlocking structure.

[0014] In an embodiment, the first driving circuit comprises a first switch, a first resistor and a second resistor.

[0015] The first end of the first switch is connected with the second end of the first resistor and the control end of the first lower bridge arm switch in the first bridge arm respectively, the second end of the first switch is grounded, and the control end of the first switch is connected with the second end of the second resistor.

[0016] The first end of the first resistor is connected with the controller and receives the first driving signal output by the controller; and the first end of the second resistor is connected with the controller and receives the second driving signal output by the controller.

[0017] The first driving signal and the second driving signal are complementary PWM driving signals.

[0018] In an embodiment, the second driving circuit comprises a second switch, a third resistor and a fourth resistor.

[0019] The first end of the second switch is connected with the second end of the third resistor and the control end of the second lower bridge arm switch in the second bridge arm respectively, the second end of the second switch is grounded, and the control end of the second switch is connected with the second end of the fourth resistor.

[0020] The first end of the third resistor is connected with the controller and receives the second driving signal output by the controller; and the first end of the fourth resistor is connected with the controller and receives the first driving signal output by the controller.

[0021] The first driving signal and the second driving signal are complementary PWM driving signals.

[0022] In an embodiment, the H-bridge circuit comprises: a first upper bridge arm switch tube, a first lower bridge arm switch tube, a second upper bridge arm switch tube, a second lower bridge arm switch tube, a fifth resistor, and a sixth resistor;

[0023] A first end of the first upper bridge arm switch tube is connected to a positive terminal of the power supply module, a second end of the first upper bridge arm switch tube is connected to a second end of the sixth resistor and a first end of the first lower bridge arm switch tube respectively, and a connection end serves as a first output end of the H-bridge circuit; a second end of the first lower bridge arm switch tube is grounded;

[0024] A first end of the second upper bridge arm switch tube is connected to the positive terminal of the power supply module, a second end of the second upper bridge arm switch tube is connected to a second end of the fifth resistor and a first end of the second lower bridge arm switch tube respectively, and a connection end serves as a second output end of the H-bridge circuit; a second end of the second lower bridge arm switch tube is grounded;

[0025] A control end of the first upper bridge arm switch tube is connected to a first end of the fifth resistor, and a control end of the second upper bridge arm switch tube is connected to a first end of the sixth resistor; a control end of the first lower bridge arm switch tube is connected to the controller, and a control end of the second lower bridge arm switch tube is connected to the controller.

[0026] In an embodiment, the H-bridge circuit further comprises:

[0027] A current collection circuit for detecting a working current of the H-bridge circuit;

[0028] A comparator for outputting a first electrical signal when the working current does not exceed a first threshold value, and outputting a second electrical signal when the working current exceeds the first threshold value;

[0029] An interlocking trigger circuit for locking the H-bridge circuit in a non-working state when the second electrical signal is received.

[0030] In an embodiment, the interlocking trigger circuit comprises:

[0031] A signal latching module for outputting a first trigger signal in a default state, and outputting a second trigger signal and locking the output of the second trigger signal when the second electrical signal is received;

[0032] A first trigger circuit connected to the signal latching module and a first lower bridge arm switch tube of a first bridge arm in the H-bridge circuit respectively, for controlling the first lower bridge arm switch tube of the first bridge arm to be turned off when the second trigger signal is received;

[0033] A second trigger circuit, which is connected to the signal latch module and the second lower bridge arm switch of the second bridge arm in the H-bridge circuit respectively, is used to control the second lower bridge arm switch of the second bridge arm to turn off when the second trigger signal is received.

[0034] In one embodiment, the signal latching module includes: a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a third switch, and a fourth switch.

[0035] The first end of the seventh resistor serves as the input terminal of the signal latch module. The second end of the seventh resistor is connected to the first end of the eighth resistor, the control terminal of the third switch, and the first end of the fourth switch. The second end of the fourth switch is grounded.

[0036] The second end of the eighth resistor and the first end of the third switch are both connected to the positive terminal of the first power supply. The second end of the third switch is connected to the control terminal of the fourth switch, the first end of the ninth resistor, and the first end of the tenth resistor. The second end of the ninth resistor is grounded.

[0037] The second end of the tenth resistor is connected to the first end of the eleventh resistor, and the connection end serves as the output end of the signal latching module. The second end of the eleventh resistor is grounded.

[0038] In one embodiment, the first trigger circuit includes a twelfth resistor and a fifth switch; the second trigger circuit includes a thirteenth resistor and a sixth switch.

[0039] The first end of the twelfth resistor serves as the input terminal of the first trigger circuit, the second end of the twelfth resistor is connected to the control terminal of the fifth switch, the second end of the fifth switch is grounded, and the first end of the fifth switch serves as the output terminal of the first trigger circuit and is connected to the control terminal of the first lower bridge arm switch of the first bridge arm.

[0040] The first end of the thirteenth resistor serves as the input terminal of the second trigger circuit, the second end of the thirteenth resistor is connected to the control terminal of the sixth switch, the second end of the sixth switch is grounded, and the first end of the sixth switch serves as the output terminal of the first trigger circuit and is connected to the control terminal of the second lower bridge arm switch of the second bridge arm.

[0041] Secondly, the present invention also discloses a control method for a sewing machine head oil pump, applied to a controller in the control system of the sewing machine head oil pump described above, comprising:

[0042] Receive oil output control commands;

[0043] Based on the preset mapping relationship between duty cycle and oil output, determine the duty cycle corresponding to the oil output carried in the oil output control command;

[0044] A PWM drive signal is generated according to the determined duty cycle, and the H-bridge circuit is driven and controlled by the PWM drive signal so that the oil output of the sewing machine head oil pump conforms to the oil output control command.

[0045] Applying the technical solution provided by the embodiments of this invention, considering that existing solutions can only achieve a one-dimensional control mode of "whether there is oil supply" and that different models and working conditions of sewing machine heads require different amounts of oil, the existing solutions have poor adaptability to different scenarios and are prone to insufficient or excessive oil supply. To address this, the solution of this application includes a human-machine interface module, which allows oil quantity control commands to be sent to the controller according to actual needs. The controller can then determine the duty cycle corresponding to the oil quantity carried in the oil quantity control command according to a preset mapping relationship between duty cycle and oil quantity, and generate a PWM drive signal according to the determined duty cycle. When the H-bridge circuit is driven and controlled according to the PWM drive signal of this duty cycle, the output power of the H-bridge circuit can be effectively controlled, ensuring that the oil quantity of the sewing machine head oil pump meets the oil quantity control command, thus ensuring that the oil quantity meets the current usage requirements of the sewing machine head and preventing insufficient or excessive oil supply.

[0046] In summary, the proposed solution can effectively control the oil pump of the sewing machine head, achieve accurate adjustment of the oil output, and thus prevent insufficient or excessive oil supply. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic diagram of the control system for a sewing machine head oil pump provided in a specific embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the control system for the sewing machine head oil pump provided in another specific embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the H-bridge circuit and the first and second driving circuits with hardware interlocking structures in a specific embodiment of the present invention.

[0051] Figure 4 This is a schematic diagram of the comparator and interlock trigger circuit in a specific embodiment of the present invention;

[0052] Figure 5 This is a flowchart illustrating the implementation of a control method for the sewing machine head oil pump in a specific embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0054] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the control system for a sewing machine head oil pump according to a specific embodiment of the present invention. The control system for the sewing machine head oil pump may include:

[0056] Power supply module 10 for outputting electrical energy;

[0057] H-bridge circuit 20 is connected to power supply module 10 and sewing machine head oil pump respectively;

[0058] Human-machine interface module 30 for issuing fuel quantity control commands;

[0059] The controller 40, which is connected to the human-machine interaction module 30 and the H-bridge circuit 20 respectively, is used to determine the duty cycle corresponding to the oil output in the oil output control command according to the preset mapping relationship between duty cycle and oil output; generate a PWM drive signal according to the determined duty cycle and drive the H-bridge circuit 20 through the PWM drive signal so that the oil output of the sewing machine head oil pump conforms to the oil output control command.

[0060] The power supply module 10 can output power to the H-bridge circuit 20. For example, in practical applications, the power supply module 10 usually needs to output high-voltage DC power. In a specific embodiment of the present invention, the power supply module 10 may include a first boost module and a second boost module. The first boost module is used to receive low-voltage DC power and boost it, while the second boost module is used to further boost the output voltage of the first boost module. The power supply module 10 in this embodiment includes a first boost module and a second boost module because, in some embodiments, the input voltage of the power supply module 10 is low. For example, the first boost module receives external 5V low-voltage DC power. Therefore, the two-stage boost module formed by the first and second boost modules can convert the low input voltage into high-voltage DC power. For example, in one case, the first boost module receives external 5V low-voltage DC power, and the output voltage of the second boost module is 110V high-voltage DC power.

[0061] In addition, in practical applications, the power supply module 10 can also be equipped with structures such as fuses and filter circuits, which can play the role of overcurrent protection and filtering, improve power quality, and ensure circuit reliability.

[0062] The power output from the power supply module 10 can supply power to the H-bridge circuit 20, which in turn powers the sewing machine head oil pump. Different output power results in different oil output volumes. In this application, the controller 40 adjusts the duty cycle of the PWM drive signal according to the oil volume control command issued by the human-machine interface module 30, thereby ensuring the output power meets the requirements, and thus ensuring the oil pump's oil output meets the requirements of the oil volume control command.

[0063] In practical applications, the human-machine interface module 30 can provide a user interface, allowing users to operate the machine via mouse, keyboard, touchscreen, buttons, etc. Furthermore, to facilitate user operation, several oil output levels can be displayed on the user interface. When the user selects a specific oil output level, the human-machine interface module 30 automatically generates an oil output control command for that level and sends it to the controller 40, ensuring that the oil output of the sewing machine head pump matches that level. Alternatively, if none of the preset oil output levels meet the user's needs, the user can directly input the desired oil output value. The human-machine interface module 30 can then generate an oil output control command carrying that value and send it to the controller 40, ensuring that the oil output of the sewing machine head pump matches that value, thus meeting the user's requirements.

[0064] When the controller 40 receives the oil dispensing control command issued by the human-machine interaction module 30, it can read the oil dispensing quantity carried in the oil dispensing control command, and then determine the duty cycle corresponding to the oil dispensing quantity carried in the oil dispensing control command according to the preset mapping relationship between the duty cycle and the oil dispensing quantity, that is, obtain the duty cycle corresponding to the oil dispensing control command.

[0065] Understandably, the mapping relationship between duty cycle and oil output can be determined in advance through experimental verification and / or theoretical analysis. For example, an experiment can be conducted in advance with a duty cycle of 10% and the oil output can be measured. If the measured value is recorded as oil output A, then the oil output corresponding to a duty cycle of 10% can be determined. Similarly, if an experiment is conducted in advance with a duty cycle of 20% and the oil output can be measured, if the measured value is recorded as oil output B, then the oil output corresponding to a duty cycle of 20% can be determined. And so on, the oil output corresponding to each duty cycle sampling point can be obtained, thereby constructing a mapping table of "oil output - duty cycle". Alternatively, a mapping curve between duty cycle and oil output can be constructed by fitting. This mapping table or this mapping curve can then serve as the preset mapping relationship between duty cycle and oil output. Of course, other implementations may have other ways of determining the mapping relationship, as long as the controller 40 can accurately and effectively control the oil output of the sewing machine head oil pump through the PWM drive signal according to the mapping relationship, and meet the requirements of the oil output control command.

[0066] After determining the duty cycle corresponding to the oil quantity control command, the controller 40 can generate the required PWM drive signal. That is, the duty cycle of the generated PWM drive signal is equal to the duty cycle determined by the controller 40 corresponding to the oil quantity control command. Then, the controller 40 will drive the H-bridge circuit 20 based on the PWM drive signal, ensuring that the oil output of the sewing machine head oil pump matches the oil output carried in the oil output control command. It can be understood that the larger the duty cycle of the PWM drive signal, the greater the output power of the H-bridge circuit 20, and the greater the oil output of the sewing machine head oil pump.

[0067] In one specific embodiment of the present invention, it may further include:

[0068] A first drive circuit 50 is connected to the first bridge arm in the H-bridge circuit 20 and the controller 40 respectively, so that the controller 40 can drive the first bridge arm in the H-bridge circuit 20 through the first drive circuit 50; and the first drive circuit 50 is a drive circuit with a hardware interlock structure, so as to prevent the first upper bridge arm switch h1 and the first lower bridge arm switch h2 in the first bridge arm from being turned on at the same time through the hardware interlock structure.

[0069] A second drive circuit 60 is connected to the second bridge arm in the H-bridge circuit 20 and the controller 40 respectively, so that the controller 40 can drive the second bridge arm in the H-bridge circuit 20 through the second drive circuit 60; and the second drive circuit 60 is a drive circuit with a hardware interlock structure, so as to prevent the second upper bridge arm switch h3 and the second lower bridge arm switch h4 in the second bridge arm from being turned on at the same time through the hardware interlock structure.

[0070] Figure 2 In this implementation, the controller 40 specifically implements the drive control of the H-bridge circuit 20 based on the first drive circuit 50 and the second drive circuit 60. Specifically, it can perform drive control of the first bridge arm in the H-bridge circuit 20 based on the first drive circuit 50 and drive control of the second bridge arm in the H-bridge circuit 20 based on the second drive circuit 60.

[0071] Furthermore, in this embodiment, the first driving circuit 50 is a driving circuit with a hardware interlock structure, which prevents the first upper bridge arm switch h1 and the first lower bridge arm switch h2 in the first bridge arm from conducting simultaneously. Similarly, the second driving circuit 60 is a driving circuit with a hardware interlock structure, which prevents the second upper bridge arm switch h3 and the second lower bridge arm switch h4 in the second bridge arm from conducting simultaneously. It can be seen that in this embodiment, the hardware interlock structure design of the first driving circuit 50 and the second driving circuit 60 realizes the driving of the hardware interlock logic of the H-bridge circuit, ensuring that the upper and lower switches of the same bridge arm will not conduct simultaneously. That is to say, even if the PWM driving signal output by the controller 40 is erroneous due to timing deviation, external interference, etc., the hardware interlock structure design of the first driving circuit 50 and the second driving circuit 60 can effectively prevent the upper and lower switches of the same bridge arm from conducting simultaneously, eliminating this short circuit risk at the hardware level, and the reliability is very high.

[0072] The specific structures of the first drive circuit 50 and the second drive circuit 60 of the hardware interlocking structure can be set and adjusted according to actual needs. In one specific embodiment of the present invention, please refer to... Figure 3 The first driving circuit 50 may specifically include: a first switching transistor Q1, a first resistor R1, and a second resistor R2.

[0073] The first terminal of the first switch Q1 is connected to the second terminal of the first resistor R1 and the control terminal of the first lower bridge arm switch h2 in the first bridge arm. The second terminal of the first switch Q1 is grounded, and the control terminal of the first switch Q1 is connected to the second terminal of the second resistor R2.

[0074] The first terminal of the first resistor R1 is connected to the controller 40 and receives the first drive signal output by the controller 40; the first terminal of the second resistor R2 is connected to the controller 40 and receives the second drive signal output by the controller 40. The first and second drive signals are complementary PWM drive signals.

[0075] In this embodiment, the required first drive circuit 50 is realized through the first switch Q1, the first resistor R1, and the second resistor R2, making the first drive circuit 50 simple in structure and highly reliable. In this embodiment, the PWM drive signal output by the controller 40 specifically includes two drive signals, namely the first drive signal and the second drive signal, denoted as PWM1 and PWM2 respectively, which are complementary PWM drive signals.

[0076] Under normal circumstances, when PWM1 is high, PWM2 should be low, and vice versa. In some implementations, if a dead time is included, both PWM1 and PWM2 may be low. However, under normal circumstances, PWM1 and PWM2 will not be high simultaneously. If both PWM1 and PWM2 are high without any protection, the upper and lower transistors of the same bridge arm will conduct simultaneously, causing a short circuit.

[0077] In this embodiment, even if the PWM1 and PWM2 output by the controller 40 are both at high level due to timing deviation, external interference, etc., the first drive circuit 50 can still achieve hardware interlocking so that the first upper bridge arm switch h1 and the first lower bridge arm switch h2 in the first bridge arm will not be turned on at the same time. Figure 3 In the example, the first bridge arm is the left bridge arm of the H-bridge circuit 20, including the first upper bridge arm switch h1 and the first lower bridge arm switch h2, and the second bridge arm is the right bridge arm of the H-bridge circuit 20, including the second upper bridge arm switch h3 and the second lower bridge arm switch h4.

[0078] In this embodiment, the first switch Q1 is a switch that conducts when the control terminal is high; for example, an N-channel MOSFET can be used. The first lower bridge arm switch h2 is also a switch that conducts when the control terminal is high. Figure 3 As can be seen from the circuit structure, when PWM1 is high and PWM2 is low, the first switch Q1 is turned off, which will not affect the drive control of the first lower bridge arm switch h2. At this time, since PWM1 is high, the first lower bridge arm switch h2 can be turned on normally. When PWM1 is low and PWM2 is high, the first lower bridge arm switch h2 can be turned off normally.

[0079] When both PWM1 and PWM2 are high, in this abnormal situation, since the first switch Q1 is turned on, the control terminal of the first lower bridge arm switch h2 is grounded. Therefore, even if both PWM1 and PWM2 are high, the first lower bridge arm switch h2 will not be turned on, which can avoid the situation where the upper and lower switches of the first bridge arm are turned on at the same time.

[0080] In one specific embodiment of the present invention, see [reference needed]. Figure 3 The second driving circuit 60 may specifically include: a second switching transistor Q2, a third resistor R3 and a fourth resistor R4;

[0081] The first terminal of the second switch Q2 is connected to the second terminal of the third resistor R3 and the control terminal of the second lower bridge arm switch h4 in the second bridge arm. The second terminal of the second switch Q2 is grounded, and the control terminal of the second switch Q2 is connected to the second terminal of the fourth resistor R4.

[0082] The first terminal of the third resistor R3 is connected to the controller 40 and receives the second drive signal output by the controller 40; the first terminal of the fourth resistor R4 is connected to the controller 40 and receives the first drive signal output by the controller 40. The first and second drive signals are complementary PWM drive signals.

[0083] In this embodiment, similar to the first driving circuit 50, the second driving circuit 60 is also composed of two resistors and one switching transistor, which has a simple structure and high reliability.

[0084] In this embodiment, the second switch Q2 is a switch that conducts when the control terminal is high, and the second lower bridge arm switch h4 is also a switch that conducts when the control terminal is high. Figure 3 As can be seen from the circuit structure, when PWM2 is high and PWM1 is low, the second switch Q2 is turned off, which will not affect the drive control of the second lower bridge arm switch h4. At this time, since PWM2 is high, the second lower bridge arm switch h4 can conduct normally. When PWM2 is low and PWM1 is high, the second lower bridge arm switch h4 can be turned off normally.

[0085] When both PWM1 and PWM2 are high, in this abnormal situation, the control terminal of the second lower bridge arm switch h4 is grounded because the second switch Q2 is turned on. Therefore, even if both PWM1 and PWM2 are high, the second lower bridge arm switch h4 will not be turned on, which can avoid the situation where the upper and lower switches of the second bridge arm are turned on at the same time.

[0086] In one specific embodiment of the present invention, the H-bridge circuit 20 includes: a first upper bridge arm switch h1, a first lower bridge arm switch h2, a second upper bridge arm switch h3, a second lower bridge arm switch h4, a fifth resistor R5, and a sixth resistor R6.

[0087] The first terminal of the first upper bridge arm switch h1 is connected to the positive terminal of the power supply module 10. The second terminal of the first upper bridge arm switch h1 is connected to the second terminal of the sixth resistor R6 and the first terminal of the first lower bridge arm switch h2, and the connection terminal serves as the first output terminal of the H-bridge circuit 20. Figure 3 This is denoted as OUT1. The second terminal of the first lower bridge arm switch transistor h2 is grounded;

[0088] The first terminal of the second upper bridge arm switch h3 is connected to the positive terminal of the power supply module 10. The second terminal of the second upper bridge arm switch h3 is connected to the second terminal of the fifth resistor R5 and the first terminal of the second lower bridge arm switch h4, and the connection terminal serves as the second output terminal of the H-bridge circuit 20. Figure 3 This is denoted as OUT2. The second terminal of the second lower bridge arm switch transistor h4 is grounded.

[0089] The control terminal of the first upper bridge arm switch h1 is connected to the first terminal of the fifth resistor R5, and the control terminal of the second upper bridge arm switch h3 is connected to the first terminal of the sixth resistor R6; the control terminal of the first lower bridge arm switch h2 is connected to the controller 40, and the control terminal of the second lower bridge arm switch h4 is connected to the controller 40. Figure 3 In the example, the control terminal of the first lower bridge arm switch h2 is driven and controlled by the first drive signal PWM1 output by the controller 40, and the control terminal of the second lower bridge arm switch h4 is driven and controlled by the second drive signal PWM2 output by the controller 40.

[0090] The H-bridge circuit 20 can typically be implemented based on two bridge arms, with a total of four switching transistors. For example, the first upper bridge arm switch h1 and the second lower bridge arm switch h4 are driven and controlled by PWM2, while the first lower bridge arm switch h2 and the second upper bridge arm switch h3 are driven and controlled by PWM1, and corresponding drive circuits are set for each of these four switches. However, this implementation takes into account that the on / off states of the first upper bridge arm switch h1 and the second lower bridge arm switch h4 are consistent, and the on / off states of the first lower bridge arm switch h2 and the second upper bridge arm switch h3 are also consistent. Therefore, this implementation includes... Figure 3The H-bridge circuit 20 shown consists of a first upper bridge arm switch h1, a first lower bridge arm switch h2, a second upper bridge arm switch h3, a second lower bridge arm switch h4, a fifth resistor R5, and a sixth resistor R6. With this structure, the on / off states of the first upper bridge arm switch h1 and the second lower bridge arm switch h4 can be kept consistent, as can the on / off states of the first lower bridge arm switch h2 and the second lower bridge arm switch h4. Furthermore, there is no need to set up drive circuits for the first upper bridge arm switch h1 and the second upper bridge arm switch h3, meaning that drive circuits are not required for the upper transistors of the two bridge arms.

[0091] Specifically, the first lower bridge arm switch h2 and the second lower bridge arm switch h4 are typically switches that conduct when the control terminal is high, for example, both are NMOS transistors. The first upper bridge arm switch h1 and the second upper bridge arm switch h3 are typically switches that conduct when the control terminal is low, for example, both are PMOS transistors. In this embodiment, please refer to... Figure 3 As can be seen from the circuit structure, when the first lower bridge arm switch h2 is turned on, the control terminal of the second upper bridge arm switch h3 is pulled low, thus turning on the second upper bridge arm switch h3. Conversely, when the second lower bridge arm switch h4 is turned on, the control terminal of the first upper bridge arm switch h1 is pulled low, thus turning on the first upper bridge arm switch h1. Therefore, it can be seen that under normal conditions, when PWM1 output by the controller 40 is high and PWM2 is low, both the first lower bridge arm switch h2 and the second upper bridge arm switch h3 are turned on, while both the first upper bridge arm switch h1 and the second lower bridge arm switch h4 are turned off. Current flows through the second upper bridge arm switch h3 and from... Figure 3 OUT2 enters the load (i.e., the sewing machine head oil pump), flows out from OUT1 and reaches the negative terminal through the first lower bridge arm switch h2. When PWM2 output by controller 40 is high and PWM1 is low, both the second lower bridge arm switch h4 and the first upper bridge arm switch h1 are turned on, while both the second upper bridge arm switch h3 and the first lower bridge arm switch h2 are turned off. Current flows through the first upper bridge arm switch h1 and from... Figure 3 OUT1 enters the load (i.e., the sewing machine head oil pump), flows out from OUT2 and reaches the negative terminal through the second lower bridge arm switch tube h4.

[0092] In one specific embodiment of the present invention, it may further include:

[0093] The current acquisition circuit is used to detect the operating current of the H-bridge circuit 20;

[0094] The comparator is used to output a first electrical signal when the operating current does not exceed a first threshold, and to output a second electrical signal when the operating current exceeds the first threshold.

[0095] An interlock trigger circuit is used to lock the H-bridge circuit 20 in a non-operating state when a second electrical signal is received.

[0096] This implementation detects the operating current of the H-bridge circuit 20 through a current acquisition circuit. When the operating current exceeds the first threshold, the comparator outputs a second electrical signal, and the interlock trigger circuit locks the H-bridge circuit 20 in a non-operating state. This implementation triggers overcurrent shutdown through hardware circuitry, ensuring the safety of the system drive circuit and equipment. It is also understood that since overcurrent shutdown is triggered by hardware circuitry, it is much faster than software protection, resulting in a very short response time in practical applications. For example, the response time is usually <10μs, allowing the circuit to be cut off instantly when an overcurrent fault occurs, preventing the drive and oil pump from burning out, thus ensuring safety from a hardware perspective.

[0097] Furthermore, it should be noted that in practical applications, the hardware protection against overcurrent faults in this implementation can be combined with software protection. That is, when the operating current exceeds the first threshold, in addition to locking the H-bridge circuit 20 in a non-operating state via an interlock trigger circuit, the detection result can also be output to the controller 40, causing the controller 40 to disable the drive control of the H-bridge circuit 20 at the software level. For example, in one scenario, the controller 40 may also set both PWM1 and PWM2 to low level at the software level. Of course, in most cases, the response time of hardware protection against overcurrent faults will be much shorter than the response time of software protection.

[0098] There are various ways to implement the current acquisition circuit. For example, the working current of the H-bridge circuit 20 can be detected based on the sampling resistor connected in series with the DC bus. Alternatively, the detection can be achieved through a current transformer. The appropriate method can be selected according to actual needs, which does not affect the implementation of this invention. Figure 4 In the example, the operating current of the H-bridge circuit 20 is recorded as current, which is converted into a voltage signal through resistor R03 and then output to the negative input terminal of comparator Comp.

[0099] The comparator can compare the detected operating current with a first threshold, for example... Figure 4 In the implementation method, the first threshold is composed of two resistors ( Figure 4 The voltage is obtained by dividing the first voltage divider resistor R01 and the second voltage divider resistor R02 in the comparator. The connection terminals of the first voltage divider resistor R01 and the second voltage divider resistor R02 are connected to the positive input terminal of the comparator Comp. Figure 4 In the example, under normal circumstances, the operating current will not exceed the first threshold. Therefore, the first electrical signal output by the comparator Comp is a default high-level signal. However, when the operating current exceeds the first threshold, the second electrical signal output by the comparator is a low-level signal.

[0100] When the interlock trigger circuit receives the second electrical signal, it needs to lock the H-bridge circuit 20 into a non-operating state. There are various ways to implement this; for example, in one specific embodiment of the present invention, the interlock trigger circuit may specifically include:

[0101] The signal latch module is used to output a first trigger signal in the default state, and when a second electrical signal is received, output a second trigger signal and lock the output of the second trigger signal;

[0102] A first trigger circuit, which is connected to the signal latch module and the first lower bridge arm switch h2 of the first bridge arm in the H-bridge circuit 20 respectively, is used to control the first lower bridge arm switch h2 of the first bridge arm to turn off when a second trigger signal is received.

[0103] The second trigger circuit, which is connected to the signal latch module and the second lower bridge arm switch h4 of the second bridge arm in the H-bridge circuit 20 respectively, is used to control the second lower bridge arm switch h4 of the second bridge arm to turn off when the second trigger signal is received.

[0104] This implementation takes into account that overcurrent usually does not last too long. Specifically, when the interlock trigger circuit receives the second electrical signal, it turns off each switch in the H-bridge circuit 20, and the operating current of the H-bridge circuit 20 will decrease. When it is lower than the first threshold, the electrical signal output by the comparator will become the first electrical signal again. It is understandable that, in order to protect against overcurrent faults and ensure safety, even if the electrical signal output by the comparator switches back from the second electrical signal to the first electrical signal, the interlock trigger circuit should continue to lock the H-bridge circuit 20 in a non-operating state until the fault is resolved by the personnel, at which point the locked state of the H-bridge circuit 20 can be actively released.

[0105] In other words, when the interlock trigger circuit receives the second electrical signal, it needs to lock the H-bridge circuit 20 into a non-operating state. Even if the received electrical signal switches back to the first electrical signal thereafter, the H-bridge circuit 20 should still remain locked into a non-operating state. Therefore, in this embodiment of the interlock trigger circuit, a signal latch module is specifically provided. The signal latch module outputs the first trigger signal in the default state, and when it receives the second electrical signal, it outputs the second trigger signal and locks the output of the second trigger signal. That is, even if the received electrical signal switches back to the first electrical signal, the signal latch module will still output the second trigger signal.

[0106] When the first trigger circuit receives the second trigger signal, it controls the first lower bridge arm switch h2 of the first bridge arm to turn off. When the second trigger circuit receives the second trigger signal, it controls the second lower bridge arm switch h4 of the second bridge arm to turn off. It can be seen that since the lower switches of both bridge arms are turned off, the H-bridge circuit 20 can be locked in a non-working state.

[0107] The signal latch module is a circuit with output signal latching function. Its specific structure can be set and adjusted according to actual needs. For example, in one specific embodiment of the present invention, see [reference needed]. Figure 4 The signal latching module may specifically include: a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a third switch Q3, and a fourth switch Q4.

[0108] The first end of the seventh resistor R7 serves as the input terminal of the signal latch module. The second end of the seventh resistor R7 is connected to the first end of the eighth resistor R8, the control terminal of the third switch Q3, and the first end of the fourth switch Q4. The second end of the fourth switch Q4 is grounded.

[0109] The second terminal of the eighth resistor R8 and the first terminal of the third switch Q3 are both connected to the positive terminal of the first power supply. Figure 4 In this example, the specific voltage is 3.3V. The second terminal of the third switch Q3 is connected to the control terminal of the fourth switch Q4, the first terminal of the ninth resistor R9, and the first terminal of the tenth resistor R10; the second terminal of the ninth resistor R9 is grounded.

[0110] The second end of the tenth resistor R10 is connected to the first end of the eleventh resistor R11, and the connection end serves as the output end of the signal latch module. The second end of the eleventh resistor R11 is grounded.

[0111] Figure 4 In the example, the third switch Q3 is specifically a switch that is turned on when the control terminal is low, and the fourth switch Q4 is a switch that is turned on when the control terminal is high. When the signal latch module receives the first electrical signal, that is, the high-level signal, the third switch Q3 is not turned on. At this time, the output terminal of the signal latch module is low, that is, the signal latch module outputs the first trigger signal in the default state.

[0112] When the signal latch module receives the second electrical signal, i.e., a low-level signal, the third switch Q3 turns on. Because the third switch Q3 is on, the control terminal of the fourth switch Q4 is high, causing the fourth switch Q4 to turn on. After the fourth switch Q4 turns on, the control terminal of the third switch Q3 is grounded. This means that even if the comparator output switches back to the first electrical signal, the control terminal of the third switch Q3 will still be low, locking the third switch Q3 in the on state. When the third switch Q3 is on, the output voltage of the first power supply positive terminal is divided by the tenth resistor R10 and the eleventh resistor R11, causing the signal latch module to output the second trigger signal, i.e., a high-level signal.

[0113] The structures of the first and second trigger circuits can also be set and selected according to actual needs, so that when the second trigger signal output by the signal latch module is received, the H-bridge circuit 20 can be locked in a non-operating state. For example, in a specific embodiment of the present invention, see [reference needed]. Figure 4 The first trigger circuit includes: a twelfth resistor R12 and a fifth switch Q5. The second trigger circuit includes: a thirteenth resistor R13 and a sixth switch Q6.

[0114] The first end of the twelfth resistor R12 serves as the input terminal of the first trigger circuit. The second end of the twelfth resistor R12 is connected to the control terminal of the fifth switch Q5. The second end of the fifth switch Q5 is grounded. The first end of the fifth switch Q5 serves as the output terminal of the first trigger circuit and is connected to the control terminal of the first lower bridge arm switch h2 of the first bridge arm.

[0115] The first end of the thirteenth resistor R13 serves as the input terminal of the second trigger circuit. The second end of the thirteenth resistor R13 is connected to the control terminal of the sixth switch Q6. The second end of the sixth switch Q6 is grounded. The first end of the sixth switch Q6 serves as the output terminal of the first trigger circuit and is connected to the control terminal of the second lower bridge arm switch h4 of the second bridge arm.

[0116] In this embodiment, the first and second trigger circuits have simple structures and high reliability. Figure 4In the example, when the signal latch module outputs a high-level signal, i.e., when the second trigger signal is output, both the fifth switch Q5 and the sixth switch Q6 are turned on. When the fifth switch Q5 is turned on, the control terminal of the first lower bridge arm switch h2 is grounded through the fifth switch Q5, making the control terminal of the first lower bridge arm switch h2 low-level, thus turning off the first lower bridge arm switch h2. Similarly, when the sixth switch Q6 is turned on, the control terminal of the second lower bridge arm switch h4 is grounded through the sixth switch Q6, making the control terminal of the second lower bridge arm switch h4 low-level, thus turning off the second lower bridge arm switch h4. Therefore, it can be seen that the first trigger circuit and the second trigger circuit in this embodiment effectively realize the functional requirements of this application.

[0117] Furthermore, it is understandable that when the fault is repaired, the control system of the sewing machine head oil pump is reset and restarted, the signal latch module can be restored to the default state, and the controller 40 can normally perform the drive control of the H-bridge circuit 20.

[0118] Applying the technical solution provided by the embodiments of this invention, considering that existing solutions can only achieve a one-dimensional control mode of "whether there is oil supply" and that different models and working conditions of sewing machine heads require different amounts of oil, the existing solutions have poor adaptability to different scenarios and are prone to insufficient or excessive oil supply. To address this, the solution of this application includes a human-machine interface module, which allows oil quantity control commands to be sent to the controller according to actual needs. The controller can then determine the duty cycle corresponding to the oil quantity carried in the oil quantity control command according to a preset mapping relationship between duty cycle and oil quantity, and generate a PWM drive signal according to the determined duty cycle. When the H-bridge circuit is driven and controlled according to the PWM drive signal of this duty cycle, the output power of the H-bridge circuit can be effectively controlled, ensuring that the oil quantity of the sewing machine head oil pump meets the oil quantity control command, thus ensuring that the oil quantity meets the current usage requirements of the sewing machine head and preventing insufficient or excessive oil supply.

[0119] In summary, the proposed solution can effectively control the oil pump of the sewing machine head, achieve accurate adjustment of the oil output, and thus prevent insufficient or excessive oil supply.

[0120] This application also discloses a control method for a sewing machine head oil pump, which can be applied to the controller in the control system of the sewing machine head oil pump as described in any of the above embodiments. (See reference...) Figure 5 This includes the following steps:

[0121] Step S501: Receive oil output control command;

[0122] Step S502: Based on the oil output control command, determine the duty cycle corresponding to the oil output control command according to the preset duty cycle and oil output mapping relationship;

[0123] Step S503: Generate a PWM drive signal according to the determined duty cycle, and drive the H-bridge circuit through the PWM drive signal so that the oil output of the sewing machine head oil pump conforms to the oil output control command.

[0124] Corresponding to the above method embodiments, the present invention also provides an electronic device, a computer-readable storage medium, and a computer program product, which can be referred to in conjunction with the above.

[0125] The electronic device may include:

[0126] Memory, used to store computer programs;

[0127] A processor is used to execute computer programs to implement the steps of the control method for the sewing machine head oil pump as described above.

[0128] The computer program product includes a computer program / instruction that, when executed by a processor, implements the steps of the above-described control method for the sewing machine head oil pump.

[0129] The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the control method for the sewing machine head oil pump described above. The computer-readable storage medium 50 referred to herein includes RAM (Random Access Memory), main memory, ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), registers, hard disks, removable disks, or any other form of storage medium known in the art.

[0130] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0132] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A control system for a sewing machine head oil pump, characterized in that, include: Power supply module used for outputting electrical energy; An H-bridge circuit is connected to the power supply module and the sewing machine head oil pump, respectively. Human-machine interface module used to issue fuel quantity control commands; The controller, which is connected to the human-machine interaction module and the H-bridge circuit respectively, is used to determine the duty cycle corresponding to the oil output volume carried in the oil output volume control command according to the preset mapping relationship between duty cycle and oil output volume; generate a PWM drive signal according to the determined duty cycle and drive the H-bridge circuit through the PWM drive signal so that the oil output volume of the sewing machine head oil pump conforms to the oil output volume control command.

2. The control system for the sewing machine head oil pump according to claim 1, characterized in that, Also includes: A first drive circuit is connected to the first bridge arm in the H-bridge circuit and the controller respectively, so that the controller can drive the first bridge arm in the H-bridge circuit through the first drive circuit; and the first drive circuit is a drive circuit with a hardware interlock structure, so as to prevent the first upper bridge arm switch and the first lower bridge arm switch in the first bridge arm from being turned on at the same time through the hardware interlock structure. A second drive circuit is connected to the second bridge arm in the H-bridge circuit and the controller respectively, so that the controller performs drive control of the second bridge arm in the H-bridge circuit through the second drive circuit; Furthermore, the second driving circuit is a driving circuit with a hardware interlock structure, which prevents the second upper bridge arm switch and the second lower bridge arm switch in the second bridge arm from being turned on simultaneously through the hardware interlock structure.

3. The control system for the sewing machine head oil pump according to claim 2, characterized in that, The first driving circuit includes: a first switching transistor, a first resistor, and a second resistor; The first terminal of the first switch is connected to the second terminal of the first resistor and the control terminal of the first lower bridge arm switch in the first bridge arm, respectively. The second terminal of the first switch is grounded, and the control terminal of the first switch is connected to the second terminal of the second resistor. The first terminal of the first resistor is connected to the controller and receives the first drive signal output by the controller; the first terminal of the second resistor is connected to the controller and receives the second drive signal output by the controller. The first driving signal and the second driving signal are complementary PWM driving signals.

4. The control system for the sewing machine head oil pump according to claim 2, characterized in that, The second driving circuit includes: a second switching transistor, a third resistor, and a fourth resistor; The first terminal of the second switch is connected to the second terminal of the third resistor and the control terminal of the second lower bridge arm switch in the second bridge arm, the second terminal of the second switch is grounded, and the control terminal of the second switch is connected to the second terminal of the fourth resistor. The first terminal of the third resistor is connected to the controller and receives the second drive signal output by the controller; the first terminal of the fourth resistor is connected to the controller and receives the first drive signal output by the controller. The first driving signal and the second driving signal are complementary PWM driving signals.

5. The control system for the sewing machine head oil pump according to claim 1, characterized in that, The H-bridge circuit includes: a first upper bridge arm switch, a first lower bridge arm switch, a second upper bridge arm switch, a second lower bridge arm switch, a fifth resistor, and a sixth resistor. The first terminal of the first upper bridge arm switch is connected to the positive terminal of the power supply module, the second terminal of the first upper bridge arm switch is connected to the second terminal of the sixth resistor and the first terminal of the first lower bridge arm switch, and the connection terminal serves as the first output terminal of the H-bridge circuit; the second terminal of the first lower bridge arm switch is grounded. The first end of the second upper bridge arm switch is connected to the positive terminal of the power supply module, the second end of the second upper bridge arm switch is connected to the second end of the fifth resistor and the first end of the second lower bridge arm switch, and the connection end serves as the second output terminal of the H-bridge circuit; the second end of the second lower bridge arm switch is grounded. The control terminal of the first upper bridge arm switch is connected to the first terminal of the fifth resistor, and the control terminal of the second upper bridge arm switch is connected to the first terminal of the sixth resistor; the control terminal of the first lower bridge arm switch is connected to the controller, and the control terminal of the second lower bridge arm switch is connected to the controller.

6. The control system for the sewing machine head oil pump according to any one of claims 1 to 5, characterized in that, Also includes: A current acquisition circuit is used to detect the operating current of the H-bridge circuit; A comparator is used to output a first electrical signal when the operating current does not exceed a first threshold, and to output a second electrical signal when the operating current exceeds the first threshold. An interlock trigger circuit is used to lock the H-bridge circuit in a non-operating state when the second electrical signal is received.

7. The control system for the sewing machine head oil pump according to claim 6, characterized in that, The interlock trigger circuit includes: The signal latching module is used to output a first trigger signal in the default state, and when the second electrical signal is received, output a second trigger signal and lock the output of the second trigger signal; A first trigger circuit, which is connected to the signal latch module and the first lower bridge arm switch of the first bridge arm in the H-bridge circuit respectively, is used to control the first lower bridge arm switch of the first bridge arm to turn off when the second trigger signal is received. A second trigger circuit, which is connected to the signal latch module and the second lower bridge arm switch of the second bridge arm in the H-bridge circuit respectively, is used to control the second lower bridge arm switch of the second bridge arm to turn off when the second trigger signal is received.

8. The control system for the sewing machine head oil pump according to claim 7, characterized in that, The signal latching module includes: a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a third switch, and a fourth switch. The first end of the seventh resistor serves as the input terminal of the signal latch module. The second end of the seventh resistor is connected to the first end of the eighth resistor, the control terminal of the third switch, and the first end of the fourth switch. The second end of the fourth switch is grounded. The second end of the eighth resistor and the first end of the third switch are both connected to the positive terminal of the first power supply. The second end of the third switch is connected to the control terminal of the fourth switch, the first end of the ninth resistor, and the first end of the tenth resistor. The second end of the ninth resistor is grounded. The second end of the tenth resistor is connected to the first end of the eleventh resistor, and the connection end serves as the output end of the signal latching module. The second end of the eleventh resistor is grounded.

9. The control system for the sewing machine head oil pump according to claim 7, characterized in that, The first trigger circuit includes a twelfth resistor and a fifth switching transistor; the second trigger circuit includes a thirteenth resistor and a sixth switching transistor. The first end of the twelfth resistor serves as the input terminal of the first trigger circuit, the second end of the twelfth resistor is connected to the control terminal of the fifth switch, the second end of the fifth switch is grounded, and the first end of the fifth switch serves as the output terminal of the first trigger circuit and is connected to the control terminal of the first lower bridge arm switch of the first bridge arm. The first end of the thirteenth resistor serves as the input terminal of the second trigger circuit, the second end of the thirteenth resistor is connected to the control terminal of the sixth switch, the second end of the sixth switch is grounded, and the first end of the sixth switch serves as the output terminal of the first trigger circuit and is connected to the control terminal of the second lower bridge arm switch of the second bridge arm.

10. A method for controlling an oil pump in a sewing machine head, characterized in that, A controller applied in the control system of the sewing machine head oil pump as described in any one of claims 1 to 9, comprising: Receive oil output control commands; Based on the preset mapping relationship between duty cycle and oil output, determine the duty cycle corresponding to the oil output carried in the oil output control command; A PWM drive signal is generated according to the determined duty cycle, and the H-bridge circuit is driven and controlled by the PWM drive signal so that the oil output of the sewing machine head oil pump conforms to the oil output control command.

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