Presser foot slow descending control method and system, electronic equipment and sewing machine

Abstract

The invention provides a presser foot slow descending control method and system, electronic equipment and a sewing machine. The method comprises the steps of obtaining target data; the target data comprises a target position, a current position and a preset slow descending position of the presser foot; the preset slow descending position is a preset pause position of the presser foot; comparing the target position with the preset slow descent position to obtain a comparison result; if the comparison result shows that slow descending is needed, descending the presser foot from the current position to the target position according to a preset slow descending strategy; and if the comparison result shows that slow descending is not needed, descending the presser foot from the current position to the target position according to a closed-loop control algorithm. The descending speed of the presser foot can be effectively reduced aiming at the electromagnet lifting presser foot, and noise is reduced. Meanwhile, the application range is wide, and the device is suitable for different electromagnet presser foot lifting machine types, such as flat sewing and overlock sewing.

Description

Technical Field

[0001] The present application belongs to the technical field of sewing machines, and relates to a presser foot slow-down control method, and in particular to a presser foot slow-down control method, system, electronic equipment and sewing machine. Background Art

[0002] In order to reduce the labor intensity of workers, sewing machines usually use electromagnets to control the lifting and lowering of the presser foot. At present, when a sewing machine is in use, the combination of electromagnets and presser foot height sensors can be used. The controller measures the presser foot height and controls the current of the electromagnet according to the optimized control algorithm, so that the presser foot can be suspended at any height. However, when a sewing machine uses an electromagnet to lift the presser foot, the presser foot is lowered by the vertical downward force of the compression spring, and a loud impact sound is generated every time the presser foot is lowered. Summary of the invention

[0003] The purpose of the present application is to provide a presser foot slow-down control method, system, electronic equipment and sewing machine, which are used to solve the problem that the existing sewing machine produces a huge impact sound when the presser foot descends.

[0004] In a first aspect, the present application provides a presser foot slow-down control method, which is applied to a sewing machine, the sewing machine comprising a presser foot, an electromagnet assembly and a sensor assembly; the electromagnet assembly comprises a magnet, and the sensor assembly comprises a magnetic detection sensor; the magnetic detection sensor is used to detect an electrical signal that changes linearly when the magnet moves up and down with the presser foot, so that the sewing machine can judge the current position of the presser foot according to the electrical signal; the sewing machine also comprises a detection device for generating a voltage signal according to a user action, so that the sewing machine can obtain the target position of the presser foot according to the voltage signal; the method comprises: obtaining target data; the target data comprises the target position, current position and preset slow-down position of the presser foot; the preset slow-down position is a preset pause position of the presser foot; comparing the target position with the preset slow-down position to obtain a comparison result; if the comparison result indicates that slow-down is required, the presser foot is lowered from the current position to the target position according to the preset slow-down strategy; if the comparison result indicates that slow-down is not required, the presser foot is lowered from the current position to the target position according to a closed-loop control algorithm.

[0005] In an implementation of the first aspect, comparing the target position and the preset slow-descent position to obtain a comparison result includes: if the height of the target position is less than the height of the preset slow-descent position, the comparison result indicates that slow-descent is required; if the height of the target position is greater than or equal to the height of the preset slow-descent position, the comparison result indicates that slow-descent is not required.

[0006] In an implementation of the first aspect, lowering the presser foot from the current position to the target position according to a preset slow-descent strategy includes: setting the preset target position of the presser foot to a first position at the same height as the preset slow-descent position according to the closed-loop control algorithm; when the presser foot slowly descends from the current position to the target position, determining whether the residence time of the presser foot at the first position is greater than or equal to a set time; if the residence time is greater than or equal to the set time, lowering the presser foot from the first position to the target position according to the closed-loop control algorithm; if the residence time is less than the set time, re-setting the preset target position of the presser foot to the first position at the same height as the preset slow-descent position according to the closed-loop control algorithm.

[0007] In an implementation of the first aspect, before comparing the target position and the preset slow-down position to obtain a comparison result, the method further includes: making a judgment based on the target position and the current position to obtain a judgment result; and judging whether the presser foot performs slow-down based on the judgment result.

[0008] In an implementation of the first aspect, judging whether the presser foot needs to be slowly lowered according to the judgment result includes: if the height of the target position is higher than the height of the current position, the judgment result is that the presser foot does not perform a slow descent, and the presser foot is raised from the current position to the target position according to the closed-loop control algorithm.

[0009] In an implementation of the first aspect, judging whether the presser foot needs to be slowly lowered according to the judgment result includes: if the height of the target position is equal to the height of the current position, the judgment result is that the presser foot does not perform a slow descent, and the position of the presser foot is maintained at the current position.

[0010] In an implementation of the first aspect, judging whether the presser foot needs to be slowly lowered according to the judgment result includes: if the height of the target position is lower than the height of the current position, further judging whether the presser foot performs slow lowering according to the target position and the preset slow lowering position.

[0011] In a second aspect, the present application provides a presser foot slow-down control system for controlling a sewing machine, the sewing machine comprising a presser foot, an electromagnet assembly and a sensor assembly; the electromagnet assembly comprises a magnet, and the sensor assembly comprises a magnetic detection sensor; the magnetic detection sensor is used to detect an electrical signal that changes linearly when the magnet moves up and down with the presser foot, so that the sewing machine can judge the current position of the presser foot according to the electrical signal; the sewing machine also comprises a detection device for generating a voltage signal according to a user action, so that the sewing machine can obtain a target position of the presser foot according to the voltage signal; the system comprises: an acquisition module for obtaining target data; the target data comprises a target position, a current position and a preset slow-down position of the presser foot; a comparison module for comparing the target position with the preset slow-down position to obtain a comparison result; a slow-down processing module for lowering the presser foot from the current position to the target position according to a preset slow-down strategy if the comparison result indicates that slow-down is required; and a non-slow-down processing module for lowering the presser foot from the current position to the target position according to a closed-loop control algorithm if the comparison result indicates that slow-down is not required.

[0012] In a third aspect, the present application provides an electronic device, comprising: a memory storing a computer program; and a processor connected to the memory, for executing the presser foot slow descent control method described above when the computer program is called.

[0013] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by an electronic device, implements the presser foot slow-descent control method described above.

[0014] In a fifth aspect, the present application provides a sewing machine, comprising the presser foot slow-descent control system as described above.

[0015] As described above, the presser foot slow-down control method, system, electronic device and sewing machine described in the present application have the following features:

[0016] Beneficial effects:

[0017] The present application compares the target position with the preset slow-down position to obtain a comparison result. If the comparison result indicates that slow-down is required, the presser foot is lowered from the current position to the target position according to the preset slow-down strategy. If the comparison result indicates that slow-down is not required, the presser foot is lowered from the current position to the target position according to a closed-loop control algorithm. This can effectively reduce the presser foot lowering speed and noise for the electromagnet presser foot lifter. At the same time, the application range is wide, and it is suitable for different electromagnet presser foot lifter models, such as flat sewing and overlock sewing.

[0018] The present application adopts a closed-loop control algorithm (PID algorithm) to control the slow descent of the presser foot, and performs closed-loop adjustment of the height through feedback from the sewing machine's head height sensor. This can achieve the technical effect of pausing at a preset slow-descent position during the descent of the presser foot to achieve the slow-descent and reduce noise technical effect, while not affecting the normal descent process of the presser foot at other positions of the preset slow-descent position.

[0019] The present application adopts a closed-loop control algorithm (PID algorithm) to control the presser foot to lower slowly, and performs closed-loop height adjustment through feedback from the head height sensor of the sewing machine. The original height control of the presser foot has a fast response, and the slow-down has little effect on it. At the same time, the existing structure of lifting the presser foot by an electromagnet does not need to be changed, and only a presser foot height sensor needs to be added, which is simple in structure and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shown is a schematic diagram of the hardware structure of a sewing machine based on an electromagnet presser foot lifting mechanism as described in an embodiment of the present application.

[0021] Figure 2 Shown is a flow chart of the presser foot slow-down control method described in an embodiment of the present application.

[0022] Figure 3 Shown is a schematic diagram of the presser foot height control process described in an embodiment of the present application.

[0023] Figure 4 Shown is a schematic diagram of the presser foot slow-down algorithm flow chart described in an embodiment of the present application.

[0024] Figure 5 Shown is a structural schematic diagram of the presser foot slow-descent control system described in an embodiment of the present application.

[0025] Figure 6 Shown is a schematic diagram of the structure of an electronic device described in an embodiment of the present application.

[0026] Component number description

[0027] 1 Electromagnet fixing

[0028] 2 Presser foot lifting solenoid

[0029] 3 Electromagnet core

[0030] 4 Reverse rear lever connector

[0031] 5 Reverse rear lever

[0032] 6 Reverse rear lever fixing shaft

[0033] 7 Tie rod

[0034] 8 Front lever

[0035] 9 Presser foot lifting plate

[0036] 10 Buffer torsion spring

[0037] 11 Torsion spring shaft screw

[0038] 12 Pressure rod guide

[0039] 13 Magnet fixing seat

[0040] 14 Sensor fixing seat

[0041] 15 Presser foot

[0042] 100 Presser foot slow-down control system

[0043] 110 Get Module

[0044] 120 Comparison module

[0045] 130 Slow-down processing module

[0046] 140 Non-slow-down processing module

[0047] 200 Electronic equipment

[0048] 210 Memory

[0049] 220 processors

[0050] S1~Sn Steps DETAILED DESCRIPTION

[0051] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0052] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0053] The following embodiments of the present application provide a presser foot slow-descent control method, system, electronic device and medium, which solve the problem that the existing sewing machine produces a huge impact sound when the presser foot descends.

[0054] like Figure 1 As shown, this embodiment provides a sewing machine with an electromagnet presser foot lifting mechanism, which specifically includes: an electromagnet fixing member (1), a presser foot lifting electromagnet (2), an electromagnet core (3), a reverse rear lever joint (4), a reverse rear lever (5), a reverse rear lever fixing shaft (6), a pull rod (7), a front lever (8), a presser foot lifting plate (9), a buffer torsion spring (10), a torsion spring axial screw (11), a presser rod guide frame (12), a magnet assembly (13), a sensor assembly (14), and a presser foot (15).

[0055] The presser foot lifting electromagnet (2) is connected to the electromagnet fixing part (1) and is reversely fixed to the sewing machine housing by screws. The electromagnet core (3) can freely move up and down in the coil frame of the presser foot lifting electromagnet (2). A threaded hole is processed at the rear end of the electromagnet core (3). The reverse rear lever joint (4) is fixed in the threaded hole and connected to the reverse rear lever (5) by a pin. The reverse rear lever (5) is fixed to the reverse rear lever fixing part (6) by an axial screw and can freely rotate around the axial screw. The connecting rod ( 7) is fixed to a threaded hole processed at one end of the reverse rear lever (5) by a screw, and is connected to the front lever (8) by a screw. The front lever (8) is connected to the presser foot lifting plate (9) by a pin. A threaded hole is processed on the presser foot lifting plate (9), and a torsion spring axial screw (11) is fixed in the threaded hole. A torsion spring (10) is wound around the torsion spring axial screw (11) and one end is pressed on the presser foot lifting plate (9), and the other end is pressed on the pressure rod guide frame (12), so that the presser foot lifting plate (9) and the pressure rod guide frame (12) will not be separated by the electromagnet. The pressure rod guide frame (12) and the presser foot lifting plate (9) are in contact with each other due to the deadweight of the iron core (3) and are kept in a state of separation, so as to prevent the pressure rod guide frame (12) and the presser foot lifting plate (9) from colliding with each other and generating noise due to the up and down movement of the feed dog of the sewing machine during the sewing process. A magnet assembly (13) is fixed on the pressure rod guide frame (12). The magnet assembly (13) includes a magnet and a magnet fixing part. The magnet is arranged in the magnet fixing part and can move up and down with the pressure rod guide frame (12) and the presser foot (15) when it is lifted and lowered. The sensor assembly (14) includes a magnetic detection sensor and a sensor fixing part. The sensor fixing part contains a magnetic detection sensor. The sensor fixing part is fixed to the sewing machine housing by screws and keeps a certain distance from the magnet on the magnet assembly (13). The magnetic detection sensor in the sensor fixing part can detect the magnetic field generated by the magnet. When the magnet moves up and down with the presser foot (15), the magnetic detection sensor in the sensor fixing part can output an electrical signal that changes linearly with the height of the magnet. The sewing machine main control determines the current presser foot height according to the signal. The sewing machine main control is used to control the operation of the sewing machine.

[0056] The technical solutions in the embodiments of the present application will be described in detail below in conjunction with the drawings in the embodiments of the present application.

[0057] like Figure 2As shown, this embodiment provides a presser foot slow-down control method, which is applied to a sewing machine, wherein the sewing machine includes a presser foot (15), a magnet assembly 13 and a sensor assembly 14 (see Figure 1 ); the magnet assembly 13 includes a magnet and a magnet fixing, and the magnet fixing is used to fix the magnet; the sensor assembly 14 includes a magnetic detection sensor and a sensor fixing, and the magnetic detection sensor is arranged in the sensor fixing seat; the magnetic detection sensor is used to detect the electric signal of the linear change when the magnet moves up and down with the presser foot, so that the sewing machine can determine the current position of the presser foot according to the electric signal; the sewing machine also includes a detection device (not shown in the figure) for generating a voltage signal according to the user's action, so that the sewing machine can obtain the target position of the presser foot according to the voltage signal.

[0058] In one embodiment, the presser foot height control principle is: the user can control the presser foot height through a pedal or an electronic kneerest. Generally, there is a detection stroke device inside the pedal or the electronic kneerest, which is composed of a linear Hall and a small magnet. When the pedal or the kneerest moves, the output voltage of the detection stroke device will also change, and the main control samples the voltage signal of the pedal or the kneerest, and converts the voltage signal into the presser foot target height. The real-time height of the presser foot is fed back by the magnetic detection sensor of the machine head, that is, the height sensor, and the presser foot height can be controlled by adjusting the current size in real time through the PID algorithm. The presser foot is lifted when the pedal is stepped back or the kneerest is pressed, and the larger the amplitude of the step back or the kneerest is pressed, the higher the presser foot is lifted. When the pedal or the kneerest is released, the presser foot drops, and the larger the release amplitude is, the more the presser foot drops, and when it is completely released, the presser foot completely falls. When the pedal or the kneerest is released, it is necessary to determine whether the presser foot needs to be slowly lowered, and the slow lowering will only be triggered when the presser foot drops to a lower height. The present application realizes the slow descent control of the presser foot by controlling the magnitude of the electromagnet input current in cooperation with the presser foot height sensor, and adopts the PID algorithm to realize the slow descent by pausing the presser foot when it passes a certain height.

[0059] like Figure 2 As shown, this embodiment provides a presser foot slow-down control method, and the method includes the following steps S1 to S4.

[0060] Step S1, obtaining target data; the target data includes the target position, current position and preset slow-descent position of the presser foot.

[0061] Specifically, when the pedal or the kneerest moves, the output voltage of the detection device on the sewing machine will also change. The main control of the sewing machine samples the voltage signal of the pedal or the electronic kneerest and converts the voltage signal into a target height of the presser foot, that is, the target position of the presser foot. The current position of the presser foot is fed back by the magnetic detection sensor of the sewing machine, that is, the height sensor. The real-time height of the presser foot, that is, the current position of the presser foot, can be controlled by adjusting the current in real time through the PID algorithm. The preset slow-down position is the preset stop position of the presser foot, and the preset slow-down position is determined by the thickness of the cloth being sewn by the sewing machine. If the height of the preset slow-down position is too high, the presser foot will still produce a relatively large impact sound when it descends from the preset slow-down position; if the height of the preset slow-down position is too low, not much cloth can be placed between the presser foot and the table. If the thickness of the cloth exceeds the height of the preset slow-down position, the presser foot will press the cloth first when it descends, and will not reach the preset slow-down position, and will directly impact the cloth, resulting in no time to execute the slow-down, and the slow-down effect will not be achieved. Therefore, the preset slow-down position should be set within a reasonable range. For example, the preset slow-down position is within the range [1.5mm, 2.5mm]. This application takes 2mm as an example for explanation, but this application is not limited to this.

[0062] Step S2: Compare the target position with the preset slow-descent position to obtain a comparison result.

[0063] Specifically, the present application compares the target position and the preset slow-down position through the main control of the sewing machine. If the target position is smaller than the preset slow-down position, it indicates that slow-down is required. Otherwise, slow-down is not required, and a closed-loop control algorithm (such as a PID algorithm) is executed to lower the presser foot from the current position to the target position.

[0064] In an embodiment of the present application, the process of obtaining a comparison result by comparing the target position with the preset slow-descent position includes the following steps S21 to S22.

[0065] Step S21: If the height of the target position is less than the height of the preset slow-descent position, the comparison result indicates that slow-descent is required.

[0066] Step S22: If the height of the target position is greater than or equal to the height of the preset slow descent position, the comparison result indicates that slow descent is not required.

[0067] Step S3: if the comparison result indicates that a slow descent is required, the presser foot is lowered from the current position to the target position according to a preset slow descent strategy.

[0068] Specifically, if the target position is less than the preset slow-down position, it means that slow-down is needed. First, by executing a closed-loop control algorithm (such as a PID algorithm), the preset target position of the presser foot is set to a first position with the same height as the preset slow-down position. For example, the height of the preset slow-down position is 2mm, and the height of the preset target position of the presser foot is set to 2mm (the current position of the presser foot is higher than the target position). It is determined whether the presser foot stays stably in the first position for a set time, such as 1ms. When the presser foot height is stable near the 2mm height for 1ms, it is determined that the presser foot descent speed is reduced to 0 at the 2mm height. Subsequently, a closed-loop control algorithm (such as a PID algorithm) is executed, and the presser foot continues to descend to the target position. For example, if the height of the target position is 1mm, the presser foot will quickly descend to the 1mm height. If the height of the target position is 0mm, the presser foot falls completely and starts to fall at the 2mm height, so that no large impact sound will be generated. If the presser foot height cannot be stabilized at a height of about 2 mm for 1 ms, it means that the presser foot cannot be slowly lowered at the 2 mm position, and a closed-loop control algorithm (such as a PID algorithm) is re-executed to set the preset target position of the presser foot.

[0069] It should be noted that the closed-loop control algorithm is not limited to the PID algorithm, and can also be implemented by other closed-loop algorithms, and this application is not limited to this. At the same time, the height of the preset slow-down position is not limited to 2mm, and the user can set it according to the actual situation, and this application is not limited to this.

[0070] In one embodiment of the present application, lowering the presser foot from the current position to the target position according to a preset slow-down strategy includes the following steps S31 to S34.

[0071] Step S31, setting the preset target position of the presser foot to a first position at the same height as the preset slow-descent position according to the closed-loop control algorithm;

[0072] Step S32: when the presser foot slowly descends from the current position to the target position, it is determined whether the stay time of the presser foot at the first position is greater than or equal to a set time.

[0073] Specifically, the set time is the presser foot dwell time, which can be tens of us or hundreds of us, and the present application is not limited thereto. The setting of the presser foot dwell time is related to the operation speed of the MCU and the sampling frequency of the height sensor. The presser foot dwell time in the present application is described by taking 1ms as an example. As for the presser foot dwell time, as long as it can be determined that the presser foot speed has dropped to 0, in principle, the time is as short as possible, and it can be determined that the presser foot has stopped.

[0074] Step S33: if the dwell time is greater than or equal to the set time, lowering the presser foot from the first position to the target position according to the closed-loop control algorithm;

[0075] Step S34: if the dwell time is less than the set time, re-execute the closed-loop control algorithm to set the preset target position of the presser foot to a first position at the same height as the preset slow-descent position.

[0076] Step S4: if the comparison result indicates that slow descent is not required, the presser foot is lowered from the current position to the target position according to a closed-loop control algorithm.

[0077] Specifically, if the target position is greater than or equal to the preset slow-down position, it means that slow-down is not required, and the closed-loop control algorithm is directly executed to lower the presser foot from the current position to the target position.

[0078] The present application realizes the slow descent control of the presser foot by controlling the magnitude of the electromagnet input current in cooperation with the presser foot height sensor, and adopts the PID algorithm to realize the slow descent by pausing the presser foot when it passes a certain height.

[0079] In an embodiment of the present application, before comparing the target position with the preset slow-descent position to obtain a comparison result, the method further includes the following steps S11 to S12.

[0080] Step S11, performing a judgment according to the target position and the current position to obtain a judgment result;

[0081] Step S12: judging whether the presser foot performs slow lowering according to the judgment result.

[0082] Specifically, to determine whether the presser foot needs to be slowly lowered, it is also necessary to determine the target position and current position of the presser foot. If the target position is higher than the current position, the presser foot needs to be lifted to reach the target position, and it is not necessary to perform slow descent at this time. The present application uses a closed-loop control algorithm (PID algorithm) to lift the presser foot to the target position. If the target position is at the same height as the current position, it is sufficient to keep the height unchanged at this time, and it is not necessary to perform slow descent. If the target position is lower than the current position, it is also necessary to perform step S2 to determine whether the presser foot performs slow descent according to the target position and the preset slow descent position, and perform steps S3 to S4 according to the comparison result in step S2.

[0083] It should be noted that the prerequisite for the above steps S2-S4 is that the target position of the presser foot is lower than the current position.

[0084] In one embodiment of the present application, judging whether the presser foot performs a slow descent according to the judgment result includes step S121A. If the height of the target position is higher than the height of the current position, the judgment result is that the presser foot does not perform a slow descent, and the presser foot is raised from the current position to the target position according to the closed-loop control algorithm.

[0085] In one embodiment of the present application, judging whether the presser foot performs a slow descent according to the judgment result includes step S121B. If the height of the target position is equal to the height of the current position, the judgment result is that the presser foot does not perform a slow descent and the position of the presser foot is maintained at the current position.

[0086] In one embodiment of the present application, judging whether the presser foot performs slow descent according to the judgment result includes step S121C. If the height of the target position is lower than the height of the current position, further judging whether the presser foot performs slow descent according to the target position and the preset slow descent position.

[0087] This application specifically describes the overall process of the presser foot slow-down control method described in this application in an embodiment. Figure 3 As shown, it is a flow chart of the presser foot height control described in the embodiment of the present application, such as Figure 4 As shown, it is shown as Figure 4 The flow chart of the presser foot slow-down algorithm is shown in .

[0088] like Figure 3 As shown, the presser foot height control process includes the following steps S51 to S58.

[0089] Step S51, the user can control the presser foot height through a pedal or an electronic kneerest. The present application collects the voltage value of the pedal or the electronic kneerest through the main control of the sewing machine, and converts the voltage signal into a presser foot target height (the height of the target position of the presser foot).

[0090] Specifically, the pedal and the electronic kneerest are internally provided with a travel detection sensor, such as a linear Hall device containing a magnetic object. At this time, the voltage value of the pedal or the electronic kneerest collected is the Hall output.

[0091] Step S52: determine whether the target height of the presser foot is greater than the actual height (the height of the current position of the presser foot).

[0092] Step S53: If the target height is higher than the actual height, there is no need to perform a slow descent. The present application uses a closed-loop control algorithm (PID algorithm) to raise the presser foot to the target height.

[0093] Step S54, determining whether the target height of the presser foot is equal to the actual height (the height of the current position of the presser foot).

[0094] Step S55: If the target height is the same as the actual height, the height can be kept unchanged and there is no need to perform a slow descent.

[0095] Step S56: If the target height is lower than the actual height, further determine whether the presser foot needs to be lowered. If the target height is lower than the actual height, step S2 needs to be executed to determine whether the presser foot needs to be lowered according to the target position and the preset lowering position.

[0096] Step S57: If the target position is smaller than the preset slow-down position, the comparison result indicates that slow-down is required, and the presser foot is lowered from the current position to the target position according to the preset slow-down strategy (see Figure 4 ).

[0097] Step S58: If the target position is greater than or equal to the preset slow-down position, the comparison result indicates that slow-down is not required, and the presser foot is lowered from the current position to the target position by executing a closed-loop control algorithm (such as a PID algorithm).

[0098] Since the electromagnet's presser foot slow descent requires closed-loop regulation, the closed-loop regulation has the following problems. On the one hand, because the compression of the pressure spring is different, the downward force on the presser foot is different, and the electromagnet current required for slow descent will also be different. At present, the prior art exists to change the compression of the pressure spring by manually rotating the pressure regulating nut on the top of the sewing machine, and the main control cannot recognize the scale of the pressure regulating nut. On the other hand, the electromagnet will heat up after being powered on for a long time, which will lead to a decrease in suction. The greater the heat, the smaller the suction generated by the same current. Therefore, the electromagnet's presser foot slow descent cannot be open-loop controlled and needs to be closed-loop controlled.

[0099] However, considering the hysteresis effect of the electromagnet and the fact that the coil current cannot change suddenly, the closed-loop control dynamic response is slow, and the presser foot height curve is not smooth but in a stepped shape, that is, the speed of the electromagnet cannot be accurately controlled by a closed loop, and it is difficult to achieve a smooth curve in which the lower the height, the slower the speed during the descent. The present application adopts a technical solution in which the presser foot speed is reduced to 0 by a closed-loop algorithm when the presser foot passes a certain height, and then continues to descend. The present application adopts a closed-loop control algorithm (such as a PID algorithm) to perform presser foot slow descent control, and performs closed-loop adjustment of the height through feedback from the head height sensor of the sewing machine.

[0100] It should be noted that the smooth curve in which the lower the height, the slower the speed during the descent means that when the presser foot drops to a very low position, for example, in the range of 0-2mm, the maximum speed at which the presser foot drops is related to the position. The lower the position, the slower the maximum speed at which the presser foot drops. The complete descent process is: the presser foot can drop quickly at the beginning, but it starts to slow down when it drops to a certain height, and the further it drops, the lower the speed. If the target speed controlled by the pedal and knee exceeds this maximum speed, it will descend at the maximum speed. This control method takes into account the response speed and slow descent of the presser foot, which is also the effect that this application hopes to achieve.

[0101] like Figure 4 As shown, the presser foot slow-down algorithm process includes the following steps S61 to S65.

[0102] Step S61. First, the present application determines the height of the target position and the height of the preset slow-descent position through the main control of the sewing machine. The height of the preset slow-descent position is illustrated by taking 2mm as an example. When the target position of the presser foot is adjusted from more than 2mm to less than 2mm, that is, when the height of the target position is less than the height of the preset slow-descent position, it indicates that slow-descent is required.

[0103] Step S62: If the height of the target position is greater than or equal to the height of the preset slow-descent position, it means that there is no need to perform slow-descent, and the presser foot is lowered from the current position to the target position by executing a closed-loop control algorithm (such as a PID algorithm).

[0104] Step S63: By executing a closed-loop control algorithm (such as a PID algorithm), the preset target position of the presser foot is set to 2 mm (the current position of the presser foot is higher than the target position).

[0105] Step S64, judging whether the presser foot height stays stably at 2mm for 1ms. When the presser foot height stays stably at 2mm for 1ms, it is judged that the presser foot descending speed is reduced to 0 at 2mm. If the presser foot height cannot stay stably at 2mm for 1ms, it means that the presser foot cannot be slowly lowered at the 2mm position, and the closed-loop control algorithm (such as PID algorithm) is re-executed to set the preset target position of the presser foot.

[0106] Step S65, then execute the closed-loop control algorithm (such as PID algorithm), and the presser foot continues to drop to the target position. For example, if the height of the target position is 1mm, the presser foot will quickly drop to 1mm. If the height of the target position is 0mm, the presser foot falls completely and starts to fall at 2mm, so no large impact sound will be produced.

[0107] It should be noted that when the target position of the presser foot is adjusted from more than 2mm to less than 2mm, a slow drop will be triggered because it is impossible to predict whether the user will completely put down the presser foot.

[0108] The user may control the presser foot to drop at a relatively fast speed until it completely falls, or may just want to quickly drop the presser foot to a lower height, such as 1mm or 0.5mm, and then maintain this height. If the presser foot target position height is 1mm or 0.5mm, no matter how high the initial height of the presser foot is, no matter how fast the user releases the pedal or kneels, the presser foot will eventually hover at 1mm or 0.5mm under the control of the closed-loop algorithm, and no impact sound will be produced in this case. If the presser foot is controlled to continue to drop to 0 height at a relatively fast speed after passing the 1mm or 0.5mm height, a loud impact sound will be produced.

[0109] The present application adopts PID algorithm to control the slow descent of the presser foot, and performs closed-loop adjustment of the height through feedback from the sewing machine's head height sensor. When the presser foot passes a certain height, the closed-loop algorithm is used to reduce the presser foot speed to 0, and then the presser foot continues to descend. In this way, the electromagnet presser foot lifting speed is effectively reduced, and the noise is reduced.

[0110] The protection scope of the presser foot slow descent control method described in the embodiment of the present application is not limited to the execution order of the steps listed in the present embodiment. All solutions implemented by adding, reducing or replacing steps in the prior art based on the principles of the present application are included in the protection scope of the present application.

[0111] The embodiment of the present application also provides a presser foot slow lowering control system, which can implement the presser foot slow lowering control method described in the present application, but the implementation device of the presser foot slow lowering control method described in the present application includes but is not limited to the structure of the presser foot slow lowering control system listed in the present embodiment. All structural deformations and replacements of the prior art made according to the principles of the present application are included in the protection scope of the present application.

[0112] like Figure 5 As shown, this embodiment provides a presser foot slow-down control system for controlling a sewing machine, the sewing machine comprising a presser foot, an electromagnet assembly and a sensor assembly; the electromagnet assembly comprises a magnet, and the sensor assembly comprises a magnetic detection sensor; the magnetic detection sensor is used to detect an electrical signal that changes linearly when the magnet moves up and down with the presser foot, so that the sewing machine can determine the current position of the presser foot according to the electrical signal; the sewing machine also comprises a detection device for generating a voltage signal according to a user action, so that the sewing machine can obtain the target position of the presser foot according to the voltage signal; the system 100 comprises: an acquisition module 110, a comparison module 120, a slow-down processing module 130 and a non-slow-down processing module 140.

[0113] The acquisition module 110 is used to acquire target data; the target data includes the target position, current position and preset slow-down position of the presser foot;

[0114] The comparison module 120 is used to compare the target position with the preset slow-descent position to obtain a comparison result;

[0115] The slow-down processing module 130 is used to lower the presser foot from the current position to the target position according to a preset slow-down strategy if the comparison result indicates that slow-down is required;

[0116] The non-slow-down processing module 140 is used to lower the presser foot from the current position to the target position according to a closed-loop control algorithm if the comparison result indicates that slow-down is not required.

[0117] It should be noted that the functions or operations of the acquisition module 110, the comparison module 120, the slow-down processing module 130 and the non-slow-down processing module 140 described in the embodiment of the present disclosure correspond one-to-one to the steps in the above-mentioned presser foot slow-down control method, so they will not be repeated here.

[0118] In the several embodiments provided in the present application, it should be understood that the disclosed system, device or method can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of modules / units is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or units can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules or units, which can be electrical, mechanical or other forms.

[0119] The modules / units described as separate components may or may not be physically separated, and the components displayed as modules / units may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules / units may be selected according to actual needs to achieve the purpose of the embodiments of the present application. For example, the functional modules / units in the various embodiments of the present application may be integrated into one processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into one module / unit.

[0120] Those of ordinary skill in the art should further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0121] In one embodiment of the present application, the present application provides a sewing machine, including the presser foot slow-descent control system as described above.

[0122] like Figure 6 As shown, this embodiment provides an electronic device, and the electronic device 200 includes: a memory 210 and a processor 220.

[0123] The memory 210 stores a computer program;

[0124] The processor 220 is connected to the memory 210, and executes the above-mentioned presser foot slow-down control method when calling the computer program. The embodiment of the present application also provides a computer-readable storage medium. It can be understood by a person of ordinary skill in the art that all or part of the steps in the method for implementing the above-mentioned embodiment can be completed by instructing the processor through a program, and the program can be stored in a computer-readable storage medium, and the storage medium is a non-transitory medium, such as a random access memory, a read-only memory, a flash memory, a hard disk, a solid-state hard disk, a magnetic tape, a floppy disk, an optical disc, and any combination thereof. The above-mentioned storage medium can be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrations. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a digital video disc (DVD)), or a semiconductor medium (for example, a solid-state hard disk (SSD)), etc.

[0125] The present application embodiment may also provide a computer program product, the computer program product including one or more computer instructions. When the computer instructions are loaded and executed on a computing device, the process or function described in the embodiment of the present application is generated in whole or in part. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer or data center.

[0126] When the computer program product is executed by a computer, the computer executes the method described in the above method embodiment. The computer program product may be a software installation package, and when the above method is required, the computer program product may be downloaded and executed on a computer.

[0127] In summary, the presser foot slow-down control method, system, electronic device and sewing machine described in the above embodiments of the present application have the following beneficial effects:

[0128] The present application compares the target position with the preset slow-down position to obtain a comparison result. If the comparison result indicates that slow-down is required, the presser foot is lowered from the current position to the target position according to the preset slow-down strategy. If the comparison result indicates that slow-down is not required, the presser foot is lowered from the current position to the target position according to a closed-loop control algorithm. This can effectively reduce the presser foot lowering speed and noise for the electromagnet presser foot lifter. At the same time, the application range is wide, and it is suitable for different electromagnet presser foot lifter models, such as flat sewing and overlock sewing.

[0129] The present application adopts a closed-loop control algorithm (PID algorithm) to control the slow descent of the presser foot, and performs closed-loop adjustment of the height through feedback from the sewing machine's head height sensor. This can achieve the technical effect of pausing at a preset slow-descent position during the descent of the presser foot to achieve the slow-descent and reduce noise technical effect, while not affecting the normal descent process of the presser foot at other positions of the preset slow-descent position.

[0130] The present application adopts a closed-loop control algorithm (PID algorithm) to control the presser foot to lower slowly, and performs closed-loop height adjustment through feedback from the head height sensor of the sewing machine. The original height control of the presser foot has a fast response, and the slow-down has little effect on it. At the same time, the existing structure of lifting the presser foot by an electromagnet does not need to be changed, and only a presser foot height sensor needs to be added, which is simple in structure and low in cost.

[0131] The descriptions of the processes or structures corresponding to the above-mentioned figures have different emphases. For parts that are not described in detail in a certain process or structure, please refer to the relevant descriptions of other processes or structures.

[0132] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A presser foot slow-down control method, characterized in that: The method comprises: Acquire target data; the target data includes a target position, a current position and a preset slow-down position of the presser foot; the preset slow-down position is a preset pause position of the presser foot; Comparing the target position with the preset slow-descent position to obtain a comparison result; If the comparison result indicates that a slow descent is required, the presser foot is lowered from the current position to the target position according to a preset slow descent strategy; If the comparison result indicates that slow descent is not required, the presser foot is lowered from the current position to the target position according to a closed-loop control algorithm.

2. The presser foot slow-down control method according to claim 1, characterized in that: Comparing the target position with the preset slow-descent position to obtain a comparison result includes: If the height of the target position is less than the height of the preset slow-descent position, the comparison result indicates that slow-descent is required; If the height of the target position is greater than or equal to the height of the preset slow-descent position, the comparison result indicates that slow-descent is not required.

3. The presser foot slow-down control method according to claim 1, characterized in that: Lowering the presser foot from the current position to the target position according to a preset slow-down strategy includes: According to the closed-loop control algorithm, the preset target position of the presser foot is set to a first position at the same height as the preset slow-descent position; When the presser foot slowly descends from the current position to the target position, determining whether the presser foot stays at the first position for a time greater than or equal to a set time; If the dwell time is greater than or equal to the set time, the presser foot is lowered from the first position to the target position according to the closed-loop control algorithm; If the dwell time is less than the set time, the preset target position of the presser foot is set to a first position at the same height as the preset slow-descent position according to the closed-loop control algorithm again.

4. The presser foot slow-down control method according to claim 1, characterized in that: Before comparing the target position with the preset slow-descent position to obtain a comparison result, the method further includes: Performing a judgment according to the target position and the current position to obtain a judgment result; It is determined whether the presser foot performs slow descent according to the determination result.

5. The presser foot slow-down control method according to claim 4, characterized in that: Judging whether the presser foot performs slow descent according to the judgment result includes: If the height of the target position is higher than the height of the current position, the judgment result is that the presser foot does not perform a slow descent, and the presser foot is raised from the current position to the target position according to the closed-loop control algorithm.

6. The presser foot slow-down control method according to claim 4, characterized in that: Judging whether the presser foot performs slow descent according to the judgment result includes: If the height of the target position is equal to the height of the current position, the judgment result is that the presser foot does not perform a slow descent, and the position of the presser foot is maintained at the current position.

7. The presser foot slow-down control method according to claim 4, characterized in that: Judging whether the presser foot performs slow descent according to the judgment result includes: If the height of the target position is lower than the height of the current position, it is further determined whether the presser foot performs slow descent according to the target position and the preset slow descent position.

8. A presser foot slow-down control system, characterized in that: The system comprises: An acquisition module is used to acquire target data; the target data includes a target position, a current position and a preset slow-down position of the presser foot; A comparison module, used for comparing the target position with the preset slow-descent position to obtain a comparison result; A slow-down processing module, configured to lower the presser foot from the current position to the target position according to a preset slow-down strategy if the comparison result indicates that slow-down is required; The non-slow-down processing module is used to lower the presser foot from the current position to the target position according to a closed-loop control algorithm if the comparison result indicates that slow-down is not required.

9. An electronic device, characterized in that: The electronic device comprises: a memory storing a computer program; A processor is connected to the memory and executes the presser foot slow-down control method according to any one of claims 1 to 7 when calling the computer program.

10. A sewing machine, characterized in that: It comprises the presser foot slow-down control system as described in claim 8.

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