High-speed electronic selvage control system based on DSP (Digital Signal Processor)

Abstract

The invention discloses a high-speed electronic selvage control system based on a DSP, and belongs to the technical field of selvage device control. Which comprises a driving motor installed in the selvedge twister, and is characterized by comprising an application layer and a driving layer, the application layer is connected with the driving layer, the application layer comprises a driving motor which is a linear motor and comprises a human-computer interface, and the output end of the human-computer interface is connected with the input end of a linear motor control module; the output end of the linear motor control module is connected with the input end of the linear motor execution module, the linear motor execution module is connected with the linear motor, and a plurality of keys are further arranged and connected with the input end of the human-computer interface. In the high-speed electronic selvage control system based on the DSP, the linear motor is adopted as a driving motor of the electronic selvage device, and meanwhile, control parameters are automatically adjusted according to position signals fed back by the position feedback device through calculation of feedback signals of the linear motor, so that control is optimal constantly.

Description

Technical Field

[0001] The invention discloses a high-speed electronic selvedge control system based on DSP, belonging to the technical field of selvedge machine control. Background Art

[0002] During the weaving process, when the front end of the weft yarn is about to leave the cloth fell, the weft yarn holder or airflow will release the weft yarn, and the front end of the weft yarn will be in a free state. Due to the tension of the weft yarn, if the weft yarn is not held in time, the weft yarn will rebound to a certain length, causing weft shrinkage on the cloth surface. Therefore, during the weaving process, it is usually necessary to set a leno machine on the loom to hold the front end of the weft yarn that is about to be in a free state.

[0003] In a traditional electronic selvedge machine, a motor is generally used as a power source, and a series of mechanical structures (such as connecting rods) are used to drive the slider in the selvedge mechanism to move up and down, and further drive the selvedge harness connected to the slider to move up and down to realize the selvedge processing work, such as: the technical solution disclosed in the Chinese utility model patent with publication number CN203530574U and patent name "An electronic selvedge machine"; the technical solution disclosed in the Chinese utility model patent with publication number CN205529277U and patent name "Multi-line electronic selvedge machine"; the technical solution disclosed in the Chinese utility model patent with publication number CN208023170U and patent name "An electronic selvedge device".

[0004] In the prior art, the motor used as the power source is generally implemented by a stepper motor. The disadvantage of using a stepper motor as the power source is that there is no feedback during the rotation of the stepper motor, so it is difficult to determine the specific position of the heddle. In addition, when using traditional motors including stepper motors as the power source, a series of intermediate transmission mechanisms need to be set when driving the slider to move up and down, so the structure is relatively complex and the probability of failure is increased. Summary of the invention

[0005] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art and provide a DSP-based high-speed electronic edge twisting control system that uses a linear motor as a driving motor for an electronic edge twisting device, and at the same time calculates the feedback signal of the linear motor and automatically adjusts the control parameters according to the position signal fed back by the position feedback device, so that the control can always achieve the optimal control.

[0006] The technical solution adopted by the present invention to solve its technical problems is: the DSP-based high-speed electronic edge twisting control system includes a driving motor installed in an edge twisting device, which is characterized by: including an application layer and a driving layer, the application layer is connected to the driving layer, wherein the application layer includes a driving motor that is a linear motor, including a human-machine interface, the output end of the human-machine interface is connected to the input end of a linear motor control module, the output end of the linear motor control module is connected to the input end of a linear motor execution module, the linear motor execution module is connected to the linear motor, and a plurality of buttons are also provided, and the buttons are connected to the input end of the human-machine interface.

[0007] Preferably, the human-machine interface receives key input through an analog-to-digital conversion module, the key input includes two states, 0 and 1, and the human-machine interface generates a key code through the key input.

[0008] Preferably, the linear motor control module generates the position parameters of the linear motor through three working modes: IO, CAN or internal enable, wherein the IO signal is input through the GPIO module.

[0009] Preferably, in IO mode, it includes level control and edge control, wherein the level control defines the position corresponding to the high level and the position corresponding to the low level, the high level corresponds to the maximum value of the feedback signal, and the low level corresponds to the minimum value of the feedback signal; the edge control automatically switches the feedback position, and a transformation is performed when the edge signal arrives.

[0010] Preferably, under level control and edge control, jitter elimination is also implemented by a delay method, and the jitter elimination time is 20ms.

[0011] Preferably, the linear motor execution module includes a PID controller, which is used to compare the position value output by the linear motor control module with the feedback value, and then perform PID operation to adjust the duty cycle and direction of the output PWM so that the linear motor reaches the position output in the motor control part program.

[0012] Preferably, an alarm monitoring module is also provided, the output end of which is connected to the input end of the linear motor control module for cutting off the power supply between the output and the motor.

[0013] Preferably, the driver layer includes initializing and updating peripheral register values, and the peripherals include ePWM, eCAN, GPIO, ADC, I2C, and SPI.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In this DSP-based high-speed electronic selvedge control system, a linear motor is used as the driving motor of the electronic selvedge device. At the same time, by calculating the feedback signal of the linear motor, the control parameters are automatically adjusted according to the position signal fed back by the position feedback device, so that the control can always reach the optimal level.

[0015] In this DSP-based high-speed electronic leno control system, the left and right leno times are controlled separately, and different leno times and angles can be set according to the characteristics of the weft yarn, with good real-time performance and high speed.

[0016] In this DSP-based high-speed electronic selvedge control system, multiple control modes coexist and can be switched through parameters, with better compatibility.

[0017] In this DSP-based high-speed electronic selvedge control system, the selvedge positioning control function is provided. It receives control instructions from the host computer and performs positioning through the PID algorithm, making the control more precise.

[0018] In this DSP-based high-speed electronic selvedge control system, the linear motor is controlled through IO and CAN. According to the different control details, the controller is divided into many control modes, and multiple control modes coexist and can be switched through parameters. It can also be adjusted and debugged without the host computer through internal enable, which has better compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the principle block diagram of the high-speed electronic selvedge control system based on DSP.

[0020] Figure 2 This is a schematic diagram of the human-machine interface of the DSP-based high-speed electronic selvedge control system.

[0021] Figure 3 It is the working diagram of the linear motor control module of the high-speed electronic twisting control system based on DSP.

[0022] Figure 4 It is a schematic diagram of the edge control mode of the linear motor control module of the high-speed electronic twisting control system based on DSP.

[0023] Figure 5 This is a schematic diagram of the linear motor control execution work of the DSP-based high-speed electronic selvedge control system. DETAILED DESCRIPTION

[0024] Figures 1 to 5 The best embodiment of the present invention is shown below in conjunction with the attached Figures 1 to 5 The present invention is further described.

[0025] like Figure 1As shown, a DSP-based high-speed electronic hemming control system (hereinafter referred to as this control system) includes an application layer and a driver layer, and the application layer is connected to the driver layer. The driver layer includes initializing and updating peripheral register values. The applied peripherals include ePWM, eCAN, GPIO, ADC, I2C, and SPI. In this DSP-based high-speed electronic hemming control system, the control object is a linear motor. In a specific electronic hemming device, a linear motor is used to replace the stepper motor in a traditional electronic hemming device. The motor shaft of the linear motor is connected to a slider in the hemming mechanism, and drives the slider in the hemming mechanism to move up and down, and further drives the hemming harness connected to the slider to move up and down to realize the hemming processing work. The specific hemming principle belongs to the common knowledge in this field and will not be repeated here.

[0026] The application layer is the functional implementation part of the entire program. In the application layer of this control system, it includes the human-machine interface, buttons, linear motor control module and linear motor execution module. The buttons are connected to the input port of the human-machine interface, the output port of the human-machine interface is connected to the input end of the linear motor control module, and the output end of the linear motor control module is connected to the input end of the linear motor execution module.

[0027] Combination Figure 2 In this control system, four buttons are set. The human-machine interface obtains input commands through four buttons. The input of the button command is collected by the analog-to-digital conversion module (ADC), and there are two states: 0 and 1. In addition, the time of collecting the button is added. It is processed by the human-machine interface and generates a button code. It not only realizes the switch state recognition of the button, but also includes the recognition of the length of the button.

[0028] The display part is used to feedback the execution of commands or the transformation of internal parameters to the user. The display is realized by controlling the shift register through SPI. The program is placed in the interrupt and the refresh frequency is 20Ms. The data types that can be displayed through the human-machine interface include decimal, binary, hexadecimal, and simple characters.

[0029] The key part of the human-machine interface is equivalent to a variable in the program by changing the value of some parameters. These are a bunch of variables with the same function packaged by a structure. Some variables related to program operation are saved in I2C and must be read from I2C every time the power is turned on. Each time a modification is made, it must be written to I2C.

[0030] like Figure 3 As shown, the linear motor control module generates position parameters through IO, CAN or internal enable. These position parameters are the input of the linear motor execution module and enable the linear motor to execute part of the program.

[0031] IO control is to realize the simplest transformation between two positions by identifying the high and low levels of GPIO. It includes: level control and edge control. Level control is to define the position corresponding to the high level and the position corresponding to the low level. The general definition is that the high level corresponds to the maximum value of the feedback signal, and the low level corresponds to the minimum value of the feedback signal.

[0032] Combination Figure 4 , the edge control feedback position signal is automatically switched, and it changes once the edge signal arrives. Therefore, in this control system, multiple positions can be set, and each edge signal changes one.

[0033] Both of the above control methods require software de-jittering programs. If the jitter is not eliminated, it may cause some wrong signals to be executed. The method of eliminating jitter here is to use the delay method. However, the delay cannot be too long. If it is too long, it will affect the response of the entire program. The maximum delay time must be able to eliminate jitter, and it must not be greater than the maximum conversion time of the machine (the maximum value of the encoder changes to the minimum value). In this control system, the de-jittering time used is 20ms. At the same time, in order to avoid interference, the DSP also has a simple filtering function for GPIO, which is to use multiple times and take the most values. If the internal hardware does not have this function. The corresponding function can also be implemented through software. Implement software filtering.

[0034] For the position corresponding to IO, a set of constant arrays can be defined to achieve it. You can also use the variable array to edit the specific position through the host computer.

[0035] The hardware part provides 3 GPIOs to input IO signals, two of which are used to control the left and right edge twisters. There is also a GPIO that can be customized. In the current program, the functions defined are: Pre-start: When this signal is triggered, the motor is only enabled to execute part of the program without inputting position parameters; Enable signal: Only when this signal is triggered, the motor control part of the program will input the position signal and enable the motor execution part of the program.

[0036] In the CAN control mode, compared with IO control, it is more flexible and has stronger anti-interference ability. It can not only be used to generate position signals, but also execute simple commands, such as modifying parameters and communicating with the host computer. This CAN controller uses the eCAN module in TMS320F2802. There is no need to wait for receiving and sending, and the hardware completes it by itself. It does not occupy software resources.

[0037] Using CAN mode to control can reduce the program load of the host computer. In a textile machine, the main control board continuously sends the angle of the machine. A 90-element 1-dimensional array is defined inside the program. The position parameters corresponding to the angle are stored. In other words, 4 degrees correspond to 1 position. The default position parameter is of sin type.

[0038] Another control method is that the human-machine interface directly realizes automatic enabling control by modifying parameters. In this mode, the generation of position parameters is provided internally, and the specific values ​​of position parameters are the values ​​in the simulated IO and CAN modes. That is, the values ​​in the IO and CAN modes are read to obtain the position values. The frequency of position parameter changes is set by the Pn parameter. Through software calculation, the Pn parameter is converted to the frequency of the hemming machine. This mode is mainly used for debugging. In the absence of any signal sent by the host computer, this mode can also be enabled to output position parameters. These position parameters are the input of the motor execution part. And enable the motor execution part of the program.

[0039] At the same time, when generating the position program, timeout monitoring is required. Timeout monitoring is used to cut off the real-time control function of the motor execution part when the host computer does not give a position signal for a long time. When executing timeout monitoring, the motor is not working in the position control mode.

[0040] like Figure 5 As shown in the figure, the linear motor execution module is used to compare the position value output by the linear motor control module with the feedback value, and then perform PID operation to adjust the duty cycle and direction of the output PWM to make the linear motor reach the position output in the motor control part program.

[0041] PID operation is a PID operation that controls according to the proportion (P), integral (I) and differential (D) of the deviation. As shown in the following formula: The above formula is the ideal PID control formula, Kp is the proportional coefficient, Ti is the integral time constant, and Td is the differential time constant. PI is an algorithm with only proportional (P) and integral (I), and the differential loop is removed (i.e. Td=0). Because the feedback value has interference, if the differential loop is added, the noise will be amplified. In actual applications, it is not necessary to use all three operations of PID, and they can be selected according to actual conditions. For example, you can directly use only P's P operation, PI operation with P and I, and PD operation with only PD.

[0042] The PI operation is shown in formula 4.1, where e(t) is the difference input, u(t) is the PI operation output, and e(t) is the input part of the PI operation. It can be seen that even if e(t)=0, u(t) still has an output due to the existence of Ti, so in the design, I in the PI operation only exists for a period of time. This can not only eliminate static errors, but also suppress oscillations.

[0043] The P parameters in this control system are respectively set in Pn104 and Pn105 to set the proportional coefficients of the two motors. These two parameters will adjust themselves during operation to reach the optimal value (Pn504.1 setting).

[0044] The above alarm monitoring module has only one output, which is connected to the input of the linear motor control module to cut off the power supply between the output and the motor. The monitoring range includes overcurrent, encoder disconnection, feedback abnormality, incorrect parameters, etc. It ensures that the motor will not work in an open-loop state or with damaged components.

[0045] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A high-speed electronic selvedge control system based on DSP, comprising a drive motor installed in a selvedge machine, characterized in that: It includes an application layer and a driving layer, the application layer is connected to the driving layer, wherein the application layer includes a driving motor which is a linear motor, and includes a human-machine interface, the output end of the human-machine interface is connected to the input end of the linear motor control module, the output end of the linear motor control module is connected to the input end of the linear motor execution module, the linear motor execution module is connected to the linear motor, and a plurality of buttons are also provided, and the buttons are connected to the input end of the human-machine interface.

2. The high-speed electronic selvedge control system based on DSP according to claim 1, characterized in that: The human-machine interface receives key input through the analog-to-digital conversion module. The key input includes two states, 0 and 1. The human-machine interface generates a key code through the key input.

3. The high-speed electronic selvedge control system based on DSP according to claim 1 is characterized in that: The linear motor control module generates the position parameters of the linear motor through three working modes: IO, CAN or internal enable, where the IO signal is input through the GPIO module.

4. The DSP-based high-speed electronic selvedge control system according to claim 3 is characterized in that: In IO mode, it includes level control and edge control. The level control defines the position corresponding to the high level and the position corresponding to the low level. The high level corresponds to the maximum value of the feedback signal, and the low level corresponds to the minimum value of the feedback signal. The edge control automatically switches the feedback position and performs a transformation when the edge signal arrives.

5. The high-speed electronic selvedge control system based on DSP according to claim 4 is characterized in that: Under level control and edge control, it also includes jitter elimination achieved by delay method, and the jitter elimination time is 20ms.

6. The high-speed electronic selvedge control system based on DSP according to claim 1 is characterized in that: The linear motor execution module includes a PID controller, which is used to compare the position value output by the linear motor control module with the feedback value, and then perform PID calculations to adjust the duty cycle and direction of the output PWM so that the linear motor reaches the position output in the motor control part program.

7. The high-speed electronic selvedge control system based on DSP according to claim 1 is characterized in that: An alarm monitoring module is also provided, the output end of which is connected to the input end of the linear motor control module and is used to cut off the power supply between the output and the motor.

8. The DSP-based high-speed electronic selvedge control system according to claim 1 is characterized in that: The driver layer includes initialization and updating of peripheral register values. The peripherals include ePWM, eCAN, GPIO, ADC, I2C, and SPI.

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