Zero-waste-yarn bottom starting control method

Abstract

The invention discloses a zero-waste-yarn bottoming control method, which is characterized in that a bottoming lifting plate and a flexible steel wire are driven and controlled by a servo motor to provide a controllable traction force when a fabric cannot be pulled at the initial stage of a roller, so that a zero-waste-yarn bottoming effect is realized; meanwhile, magnetized magnetic steel is embedded in the tail of a motor shaft of the wire feeding motor, a magnetic angle sensing chip of the wire feeding motor driving plate is in coupling connection with the magnetic steel, when the wire feeding motor rotates, the magnetic steel at the tail of the motor shaft synchronously rotates along with the motor shaft, and when the magnetic steel rotates, a magnetic field also rotates along with the motor shaft; the change of the magnetic field is sensed and detected through the magnetic angle sensing chip, and the number of rotation turns and the position of the wire feeding motor are recorded. According to the invention, the control precision is improved, the risk of wire harness breakage is significantly reduced, the installation is simplified, and the overall cost is effectively reduced; meanwhile, a control line and a feedback line of the wire feeding motor are saved, and installation is further simplified.

Description

Technical Field

[0001] This invention belongs to the field of computerized flat knitting machine control technology, specifically relating to a zero-waste yarn raising control method. Background Technology

[0002] In existing technologies, computerized flat knitting machines require the initial knitting of a base section of approximately 6cm to fill the gap between the knitting opening and the rollers, allowing the rollers to hold the fabric in place. Once the rollers hold the fabric, the fabric is stretched controllably, thus achieving the desired knitting effect. This base knitting method results in a section of waste yarn under each piece of fabric. This waste yarn needs to be manually removed piece by piece later, requiring more manpower. The use of waste yarn is a cost that cannot be ignored.

[0003] Some technologies have proposed zero-waste yarn starting solutions, which can effectively avoid the three unavoidable drawbacks of the aforementioned transmission knitting process. They eliminate the need for waste yarn and manual sheet separation, saving costs and improving efficiency. However, they still have the following drawbacks: The stepper motor controls the raising plate lifting mechanism. Since each step of a stepper motor has a fixed travel distance, the movement of the stepper motor when controlling the raising plate to pull the fabric is rather stiff, especially noticeable in finely knitted fabrics (this is not the case for coarsely knitted fabrics). This can result in the raising plate moving too far, pulling the fabric too tightly, or moving too little, resulting in too loose a tension. In such cases, the knitting effect is not ideal. Furthermore, in existing zero-waste yarn raising control methods, the yarn feeding motor is fixed to the raising plate and moves up and down with it. The control method uses one control line and four feedback signal lines for the yarn feeding motor. Both of the two yarn feeding motor encoder lines require flexible wire harnesses, fixed to the raising plate and moving up and down with it. Despite using flexible wire harnesses, improper binding methods often lead to breakage of the feedback wire harnesses. Additionally, the large number of flexible wire harnesses increases control costs.

[0004] Therefore, the applicant hopes to find a technical solution to address the technical problems existing in the above-mentioned zero-waste yarn bottoming solution. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a zero-waste yarn raising control method, which not only improves control accuracy but also significantly reduces the risk of yarn bundle breakage, while simplifying installation and effectively reducing overall costs; at the same time, this application saves control lines and feedback lines for the yarn feeding motor, further simplifying installation.

[0006] The technical solution adopted in this invention is as follows: A zero-waste yarn raising control method employs a servo motor-driven raising lifting plate and a separate yarn feeding motor drive plate installed at the tail of the yarn feeding motor. The servo motor drives the raising lifting plate and flexible steel wire to provide controllable traction force to the fabric when the rollers cannot initially pull it, achieving a zero-waste yarn raising effect. Simultaneously, a magnetized magnet is embedded at the tail of the yarn feeding motor shaft. A magnetic angle sensing chip on the yarn feeding motor drive plate is coupled to this magnet. When the yarn feeding motor rotates, the magnet at the tail of the motor shaft rotates synchronously with the motor shaft. As the magnet rotates, the magnetic field also rotates. The magnetic angle sensing chip detects this change in the magnetic field, recording the number of rotations and position of the yarn feeding motor.

[0007] Preferably, a four-core cable is used to power and communicate with the wire feeding motor drive board, eliminating the need for a flexible drag chain cable to connect the sensors of the wire feeding motor.

[0008] Preferably, the magnetic angle sensing chip is an MA730GQ model magnetic angle sensing chip, which works based on the Hall effect; wherein, when the magnetic angle sensing chip senses a change in the magnetic field, it converts the strength and direction of the magnetic field into a voltage signal and transmits it to the main control chip of the flat knitting machine. The main control chip calculates the current number of rotations and position of the wire feeding motor based on the voltage signal.

[0009] Preferably, the wire feeding motor is a stepper motor with a fixed angle per step, so that the number of pulses per revolution of the wire feeding motor is a fixed value. During the period when the main control chip enables the driver chip of the wire feeding motor, the number of revolutions of the wire feeding motor is calculated based on the number of enable pulses sent by the main control chip to the driver chip of the wire feeding motor. Then, the theoretical number of revolutions of the corresponding wire feeding motor calculated by the main control chip based on the total number of pulses is compared with the actual number of revolutions calculated based on the output signal of the magnetic angle sensing chip, and the comparison is used to determine whether the wire feeding motor has reached the designated position.

[0010] Preferably, the main control chip is an STM32F103C8T6; the drive chip for the wire feeding motor is a DRV8452DDWR.

[0011] Preferably, the MA730GQ magnetic angle sensing chip is provided with pin 2, pin 3 and pin 6 output respectively. These three are used as incremental gain output pins to output the voltage signal used to sense changes in the magnetic field.

[0012] Preferably, the MA730GQ magnetic angle sensing chip also has a pin 5 output; when the output signal of this pin is high, the MA730GQ magnetic angle sensing chip enters the working state.

[0013] Preferably, the MA730GQ magnetic angle sensing chip is also provided with output pins 4, 7, and 12. These three pins serve as the external serial communication interface for SP1, with synchronous clock control and full-duplex communication. They are also connected in real time to the main control chip of the computer flat knitting machine to calculate the magnetic field position and then calculate the rotation angle of the wire feeding motor.

[0014] Preferably, the motor shaft of the wire feeding motor is provided with an embedding groove, and a magnet with a radial magnetic ring is embedded in the embedding groove, which corresponds to the magnetic angle sensing chip.

[0015] Preferably, the drive chip of the wire feeding motor is provided with an enable signal pin, a pulse speed signal pin, and a direction signal; wherein, the enable signal pin is used to receive the enable signal output from the main control chip, and enters normal operation after receiving the enable signal; the pulse speed signal pin is used to receive the PWM pulse output from the main control chip, and is used to control the speed of the wire feeding motor; the direction signal is used to receive the high and low level signals output from the main control chip, and is used to control the forward and reverse direction of the wire feeding motor.

[0016] It should be noted that the structural basis of the application scenario of this application can be directly referred to the applicant's prior application: 202010210937.7. This application does not involve any innovative content related to these basic structures, so it will not be described in detail here.

[0017] This application uses a servo motor instead of a traditional stepper motor to drive the lifting plate, which not only improves control precision but also significantly reduces the risk of wire breakage. It also simplifies installation and effectively reduces overall costs. Especially when making fine knitted fabrics, the servo motor's lifting position is more accurate, and the tension applied to the fabric is better controlled, resulting in a significant improvement in the quality of the fine knitted fabric. Furthermore, this application proposes to install the yarn feeding motor drive board separately at the tail of the yarn feeding motor, which greatly saves on the control and feedback lines previously required for the yarn feeding motor and further simplifies installation. In particular, the position detection method makes position checks more accurate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the MA730GQ magnetic angle sensing chip according to a specific embodiment of this application; Figure 2 This is a schematic diagram of the structure of the DRV8452DDWR driver chip in a specific embodiment of this application. Detailed Implementation

[0019] This invention discloses a zero-waste yarn raising control method, which employs a servo motor to drive a raising lifting plate and a separate yarn feeding motor drive plate installed at the tail of the yarn feeding motor. The servo motor drives the raising lifting plate and flexible steel wire to provide controllable traction force to the fabric when the rollers cannot initially pull it, achieving a zero-waste yarn raising effect. Simultaneously, a magnetized magnet is embedded at the tail of the yarn feeding motor shaft. A magnetic angle sensing chip on the yarn feeding motor drive plate is coupled to this magnet. When the yarn feeding motor rotates, the magnet at the tail of the motor shaft rotates synchronously with the motor shaft. As the magnet rotates, the magnetic field also rotates. The magnetic angle sensing chip detects this change in the magnetic field, recording the number of rotations and position of the yarn feeding motor.

[0020] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0021] Please refer to the above. Figure 1 and Figure 2 As shown, a zero-waste yarn raising control method employs a servo motor to drive a raising lifting plate and a separate yarn feeding motor drive plate installed at the tail of the yarn feeding motor. The servo motor drives the raising lifting plate and flexible steel wire to provide controllable traction force to the fabric when it cannot be pulled up by the rollers in the initial stage, achieving a zero-waste yarn raising effect. Simultaneously, a magnetized magnet is embedded at the tail of the motor shaft of the yarn feeding motor. A magnetic angle sensing chip on the yarn feeding motor drive plate is coupled to this magnet. When the yarn feeding motor rotates, the magnet at the tail of the motor shaft rotates synchronously with the motor shaft. As the magnet rotates, the magnetic field also rotates. The magnetic angle sensing chip detects this change in the magnetic field, recording the number of rotations and position of the yarn feeding motor. Preferably, in this embodiment, the tail of the motor shaft of the yarn feeding motor has an embedded groove, in which a magnet with a radial magnetic ring is embedded, corresponding directly to the magnetic angle sensing chip.

[0022] Preferably, in this embodiment, a four-core cable is used to power and communicate with the wire feeding motor drive board, eliminating the need for a flexible drag chain cable to connect the sensor of the wire feeding motor. Specifically, in this embodiment, the four-core cable can be a 2C*20AWG+1P shielded twisted pair cable.

[0023] Preferably, please refer to Figure 1As shown, in this embodiment, the magnetic angle sensing chip adopts the MA730GQ model magnetic angle sensing chip, which works based on the Hall effect. When the magnetic angle sensing chip senses a change in the magnetic field, it converts the strength and direction of the magnetic field into a voltage signal and transmits it to the main control chip of the flat knitting machine. The main control chip calculates the current number of rotations and position of the wire feeding motor based on the voltage signal. More preferably, in this embodiment, the MA730GQ magnetic angle sensing chip is provided with pin 2 output A, pin 3 output Z and pin 6 output B, which are used as incremental gain output pins to output voltage signals for sensing changes in the magnetic field. In a further preferred embodiment, the MA730GQ magnetic angle sensing chip is also provided with pin 5, CS, for output; when the output signal of this pin is high, the MA730GQ magnetic angle sensing chip enters the working state.

[0024] In a further preferred embodiment, the MA730GQ magnetic angle sensing chip is also provided with output MOSI at pin 4, output MISO at pin 7, and output SCLK at pin 12. These three pins serve as the external serial communication interface for SP1, with synchronous clock control and full-duplex communication; and are connected to the main control chip of the computer flat knitting machine in real time to calculate the magnetic field position, and then calculate the rotation angle of the wire feeding motor.

[0025] Preferably, in this embodiment, the wire feeding motor is a stepper motor with a fixed angle per step, so that the number of pulses per revolution of the wire feeding motor is a fixed value. During the enable period of the main control chip to the drive chip of the wire feeding motor, the number of revolutions of the wire feeding motor is calculated based on the number of enable pulses sent by the main control chip to the drive chip of the wire feeding motor. Then, the theoretical number of revolutions of the corresponding wire feeding motor calculated by the main control chip based on the total number of pulses is compared with the actual number of revolutions calculated based on the output signal of the magnetic angle sensor chip. Based on the comparison, it is determined whether the wire feeding motor has reached the designated position. Furthermore, if the two values ​​are within the allowable free range, it means that the control of the wire feeding motor has not missed any steps or encountered any obstacles, and has reached the designated position normally. The flat knitting machine control system can then perform subsequent control actions.

[0026] Preferably, in this embodiment, the main control chip is an STM32F103C8T6; the drive chip for the wire feeding motor is a DRV8452DDWR.

[0027] Preferably, please refer to Figure 2As shown, in this embodiment, the drive chip of the wire feeding motor is provided with an enable signal pin 41, a pulse speed signal pin 39, and a direction signal 40. The enable signal pin 41 is used to receive the enable signal output from the main control chip and enters normal operation after receiving the enable signal. The pulse speed signal pin 39 is used to receive the PWM pulse output from the main control chip and is used to control the speed of the wire feeding motor. The direction signal 40 is used to receive the high and low level signals output from the main control chip and is used to control the forward and reverse directions of the wire feeding motor.

[0028] This embodiment uses a servo motor instead of a traditional stepper motor to drive the bottom lifting plate, which not only improves control accuracy but also significantly reduces the risk of wire breakage. It also simplifies installation and effectively reduces overall costs. Especially when making fine knitted fabrics, the servo motor's lifting position is more accurate, and the tension applied to the fabric is better controlled, resulting in a significant improvement in the quality of the fine knitted fabric. Furthermore, this embodiment proposes to install the yarn feeding motor drive board separately at the tail of the yarn feeding motor, which greatly saves on the control and feedback lines previously required for the yarn feeding motor, further simplifying installation. In particular, the position detection method makes position change checks more accurate.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A zero-waste yarn raising control method, characterized in that, A servo motor drives the bottom lifting plate and a separate yarn feeding motor drive board installed at the tail of the yarn feeding motor. The servo motor drives the bottom lifting plate and flexible steel wire to provide controllable traction force to the fabric when the rollers cannot pull it up in the initial stage, achieving a zero-waste yarn bottom lifting effect. At the same time, a magnetized magnet is embedded at the tail of the motor shaft of the yarn feeding motor. The magnetic angle sensing chip of the yarn feeding motor drive board is coupled to the magnet. When the yarn feeding motor rotates, the magnet at the tail of the motor shaft rotates synchronously with the motor shaft. When the magnet rotates, the magnetic field also rotates. The magnetic angle sensing chip senses and detects the change in the magnetic field, realizing the recording of the number of rotations and position of the yarn feeding motor.

2. The zero-waste yarn raising control method according to claim 1, characterized in that, A four-core cable is used to power and communicate with the wire feed motor drive board, eliminating the need for a flexible cable chain to connect the wire feed motor's sensors.

3. The zero-waste yarn raising control method according to claim 1, characterized in that, The magnetic angle sensing chip uses the MA730GQ model and operates based on the Hall effect. When the magnetic angle sensing chip senses a change in the magnetic field, it converts the strength and direction of the magnetic field into a voltage signal and transmits it to the main control chip of the flat knitting machine. The main control chip calculates the current number of rotations and position of the wire feeding motor based on the voltage signal.

4. The zero-waste yarn raising control method according to claim 3, characterized in that, The wire feeding motor is a stepper motor with a fixed angle per step, so that the number of pulses per revolution of the wire feeding motor is a fixed value. During the period when the main control chip enables the driver chip of the wire feeding motor, the number of revolutions of the wire feeding motor is calculated based on the number of enable pulses sent by the main control chip to the driver chip of the wire feeding motor. Then, the theoretical number of revolutions of the corresponding wire feeding motor calculated by the main control chip based on the total number of pulses is compared with the actual number of revolutions calculated based on the output signal of the magnetic angle sensor chip. Based on the comparison, it is determined whether the wire feeding motor has reached the designated position.

5. The zero-waste yarn raising control method according to claim 4, characterized in that, The main control chip is an STM32F103C8T6; the driver chip for the wire feeding motor is a DRV8452DDWR.

6. The zero-waste yarn raising control method according to claim 3, characterized in that, The MA730GQ magnetic angle sensing chip is equipped with pin 2 (A), pin 3 (Z), and pin 6 (B) for output. These three pins are used as incremental gain output pins to output voltage signals for sensing changes in the magnetic field.

7. The zero-waste yarn raising control method according to claim 6, characterized in that, The MA730GQ magnetic angle sensing chip also has a pin 5 output (CS); when the output signal of this pin is high, the MA730GQ magnetic angle sensing chip enters the working state.

8. The zero-waste yarn raising control method according to claim 6, characterized in that, The MA730GQ magnetic angle sensing chip is also equipped with output pins 4 (MOSI), 7 (MISO), and 12 (SCLK). These three pins serve as the external serial communication interface for SP1, with synchronous clock control and full-duplex communication. They are also connected in real time to the main control chip of the computer flat knitting machine to calculate the magnetic field position and then calculate the rotation angle of the wire feeding motor.

9. The zero-waste yarn raising control method according to claim 1, characterized in that, The motor shaft of the wire feeding motor is provided with an embedding groove, in which a magnet with a radial magnetic ring is embedded, and the magnet corresponds to the magnetic angle sensing chip.

10. The zero-waste yarn raising control method according to claim 5, characterized in that, The drive chip of the wire feeding motor is provided with an enable signal pin (41), a pulse speed signal pin (39), and a direction signal (40); wherein, the enable signal pin (41) is used to receive the enable signal output from the main control chip, and enters normal operation after receiving the enable signal; the pulse speed signal pin (39) is used to receive the PWM pulse output from the main control chip, and is used to control the speed of the wire feeding motor; the direction signal (40) is used to receive the high and low level signals output from the main control chip, and is used to control the forward and reverse direction of the wire feeding motor.

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