A knitting machine host multi-servo motor synchronous control system and control method

Abstract

A knitting machine host multi-servo motor synchronous control system and control method, belonging to a knitting machine control system. The control panel of the control system is connected to the input end of the PLC, and is used to set the internal parameters of the PLC, control the operation and operation speed of the servo motor; the output end of the PLC is connected to the input end of the first servo driver KQ1 and the second servo driver KQ2, and the output ends of the first servo driver KQ1 and the second servo driver KQ2 are respectively connected to the first servo motor SM1 and the second servo motor SM2, and the PLC controls the operation of the first servo motor SM1 and the second servo motor SM2 through the first servo driver KQ1 and the second servo driver KQ2; the first servo motor SM1 and the second servo motor SM2 are meshed with the host dial gear through the motor transmission gear to drive the knitting machine host to operate. Advantages: The knitting machine motor speed is adjusted to the rated speed for normal operation, and the yarn can be replaced without stopping the machine, which is convenient for knitting operations, and the quality and output of the product are stably improved, and the waste of the product is reduced.

Description

Technical Field

[0001] The invention relates to a braiding machine control system, in particular to a braiding machine host multi-servo motor synchronous control system and a control method. Background Art

[0002] There are more and more types of braiding machines, and the number of spindles has increased from dozens to hundreds, and from small braiding machines to large braiding machines, and the application fields are becoming more and more extensive. In particular, large braiding machines are mostly used in the fields of national defense, marine cables, and carbon fiber.

[0003] At present, large-scale braiding machines have large machine running surfaces and great resistance during operation. If a high-power motor is used for single-point transmission, the transmission point will fail due to excessive force; if a high-power motor with a transmission mechanism is dispersed into multi-point transmission, the structure of the machine will be changed due to the addition of a transmission mechanism, which will make it inconvenient to install the core wire and yarn, affecting the weaving of the product. Some braiding machines use multiple three-phase asynchronous motors for frequency conversion control. The three-phase asynchronous motors are tested and manually debugged at low speed. Since the output torque of the three-phase asynchronous motor is small at low frequency, the braiding machine is difficult to start. If a reducer is added to increase the torque to compensate for the difficulty of starting at low speed, the rated speed of the braiding machine will be limited due to the addition of a reducer, and it cannot run at high speed, affecting the braiding speed and output.

[0004] The servo motor can ensure constant torque at both low and high speeds, meeting the normal startup of the machine.

[0005] Because the knitting machine mainframe uses gear transmission between the various dials, it is inevitable that there are gaps of varying sizes between the transmission gears. Using servo motors as driving power, it is difficult to achieve synchronous operation of multiple servo motors. Some servo motors will be subjected to excessive force and some servo motors will experience regeneration. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a knitting machine host multi-servo motor synchronous control system and control method to solve the problem that the existing large knitting machine host has difficulty running at low speed and multiple servo motors cannot operate synchronously.

[0007] The object of the present invention is achieved in this way. The synchronous control of multiple servo motors of a knitting machine host of the present invention includes a servo motor synchronous control system and a control method based on the servo motor synchronous control system.

[0008] The servo motor synchronous control system includes: a control panel, a PLC and a servo drive device. The control panel is connected to the input end of the PLC to set the internal parameters of the PLC; the output end of the PLC is connected to the servo drive device to control the servo drive device to drive the operation and operation speed of the knitting machine.

[0009] The servo drive device has at least two sets with the same structure, including: a servo drive and a servo motor, wherein the output end of the servo drive is connected to the servo motor to form a set of servo drive devices, and the servo drive drives the servo motor to operate;

[0010] The two sets of servo drive devices include: a first servo driver KQ1, a second servo driver KQ2, a first servo motor SM1 and a second servo motor SM2; the output end of the PLC is connected to the input end of the first servo driver KQ1 and the second servo driver KQ2, and the output ends of the first servo driver KQ1 and the second servo driver KQ2 are respectively connected to the first servo motor SM1 and the second servo motor SM2, and the PLC controls the operation of the first servo motor SM1 and the second servo motor SM2 respectively through the first servo driver KQ1 and the second servo driver KQ2; the first servo motor SM1 and the second servo motor SM2 are meshed with the main machine dial gear through the motor transmission gear to drive the knitting machine main machine to operate.

[0011] The PLC includes input port X0, input port X1, input port X2, input port X3, input port X4, output port Y0 and output port Y2; output port Y6 and output port Y7;

[0012] PLC input port X0 is the start input signal port, which is connected to the external start button SB1 of the knitting machine; PLC input port X1 is the stop input signal port, which is connected to the external stop button SB2 of the knitting machine; PLC input port X2 is the emergency stop signal port, which is connected to the external emergency stop button S1 of the knitting machine; PLC input port X3 is the alarm signal port of the first servo driver KQ1, which is connected to the KQ1 alarm output signal port ALM1, and is used to detect whether the first servo driver KQ1 has an alarm output; PLC input port X4 is the alarm port of the second servo driver KQ2, which is connected to the KQ2 alarm output signal port ALM2, and is used to detect whether the second servo driver KQ2 has an alarm output;

[0013] PLC output port Y0 is a high-speed pulse output port, which is connected to KQ1 pulse input port PP; PLC output port Y0 sends a pulse signal to KQ1 pulse input port PP to control the running speed of the first servo motor SM1; PLC output port Y2 is connected to the direction signal input port NP of the first servo driver KQ1, and PLC output port Y2 outputs a direction signal to KQ1 direction signal input port NP to control the running direction of the first servo motor SM1.

[0014] The first output port MO1 of KQ1 of the first servo driver is connected to the speed input port VLA of KQ2 of the second servo driver. The first output port MO1 of KQ1 outputs the speed signal of the first servo motor SM1, and outputs the real-time value of the speed of the first servo motor SM1 to the speed input port VLA of KQ2 to control the speed and direction of the second servo motor SM2.

[0015] At the same time, the second output port MO2 of the first servo driver KQ1 is connected to the torque input port TC of the second servo driver KQ2, and the second output port MO2 of KQ1 outputs the current value of the torque of the first servo motor SM1 to the torque input port TC of KQ2 to control the operating torque of the second servo motor SM2;

[0016] The second servo driver KQ2 controls the operation of the second servo motor SM2 according to the speed and torque signals received from the first servo driver KQ1.

[0017] A control method based on a servo motor synchronous control system: the first servo driver KQ1 directly sends the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2, and the second servo driver KQ2 controls the operation of the second servo motor SM2 according to the received speed and torque signals.

[0018] The specific steps are as follows:

[0019] Step 1: Check whether the circuit wiring is correct. After the inspection is completed, connect the power supply, power on the machine, and complete the PLC system initialization self-test. After the PLC detects that there is no fault or alarm information in the external electrical appliances;

[0020] Press the external start button SB1 of the knitting machine, the PLC output port Y6 outputs an external enable signal to the first servo driver KQ1 and the second servo driver KQ2, then the PLC pulse output port Y0 outputs a pulse signal to the KQ1 pulse input port PP to control the running speed of the first servo driver KQ1, the PLC output port Y2 outputs a running direction signal to the KQ1 direction signal input port NP, and at the same time the PLC Y7 output port outputs a start signal to the KQ2 start signal port RS1 of the second servo driver, the first servo driver KQ1 and the second servo driver KQ2 run at the same time, the first servo driver KQ1 and the second servo driver KQ2 respectively drive the first servo motor SM1 and the second servo motor SM2 to run synchronously;

[0021] Step 2: Adjust the control panel to speed up or slow down the speed of the first servo motor SM1, and control the speed of the first servo motor SM1 and the second servo motor SM2 to speed up or slow down synchronously; the specific control method is as follows:

[0022] Step 2-1, when adjusting the control panel to speed up the speed of the first servo motor SM1, the PLC will automatically speed up the pulse output frequency of the output port Y0 after internal calculation, and the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will increase, and the speed of the first servo motor SM1 driven by the first servo driver KQ1 will be accelerated. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will increase, and the speed signal received by the speed input port VLA on the second servo driver KQ2 will also increase, and the speed of the second servo motor SM2 driven by the second servo driver KQ2 will be accelerated, thereby achieving synchronous speed-up with the first servo motor SM1.

[0023] Step 2-2, when adjusting the control panel to reduce the speed of the first servo motor SM1; the PLC will automatically reduce the pulse output frequency of the PLC output port Y0 after internal calculation. As the pulse frequency output by the PLC output port Y0 decreases, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will decrease, and the speed of the first servo motor SM1 will decrease. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will decrease, and the speed signal received by the speed input port VLA of the second servo driver KQ2 will decrease. The speed of the second servo motor SM2 controlled by the second servo driver KQ2 will also decrease, thereby achieving synchronous speed reduction with the first servo motor SM1.

[0024] Step 3: The servo driver controls the operation of the servo motor. When the load of the knitting machine changes, the operating torques of the first servo motor SM1 and the second servo motor SM2 will change with the change of the load of the knitting machine, and the control system will reduce the operating torque of the servo motor or increase the operating torque of the servo motor.

[0025] The first servo driver KQ1 detects the real-time torque signal of the first servo motor SM1, and the torque signal output by the second output port MO2 of the first servo driver KQ1 is given to the torque input port TC of the second servo driver KQ2. The second servo driver KQ2 controls the rotation torque of the second servo motor SM2 according to the received torque signal. The specific control method is as follows:

[0026] Step 3-1, when the load of the braiding machine decreases, the operating torque of the first servo motor SM1 will decrease, the torque signal collected by the first servo driver KQ1 will decrease, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also decrease, the torque signal received by the torque input port TC of the second servo driver KQ2 will also decrease, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also decrease;

[0027] Step 3-2, when the load of the braiding machine increases, the operating torque of the first servo motor SM1 increases, the torque signal collected by the first servo driver KQ1 becomes larger, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also increase, the torque signal received by the torque input port TC of KQ2 will also increase, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also increase.

[0028] Beneficial effect: By adopting the above scheme and using a multi-servo motor synchronous control system and a control method, it is possible to send the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2 in real time when the speed and torque of the first servo motor SM1 change, and the second servo driver KQ2 controls the synchronization of the second servo motor SM2 and the first servo motor SM1.

[0029] When the speed of the first servo motor SM1 is reduced in the control panel, the pulse output frequency of the output port Y0 of the PLC is reduced. As the pulse frequency of the output port Y0 of the PLC is reduced, the pulse frequency received by the first servo driver KQ1 is also reduced, and the speed of the first servo motor SM1 controlled by the first servo driver KQ1 is reduced accordingly. The speed signal output by the first output port MO1 of the first servo driver KQ1 is also reduced, and the speed input signal received by the speed input port VLA of the second servo driver KQ2 is also reduced, and the speed of the second servo motor SM2 driven by the second servo driver KQ2 is also reduced;

[0030] When the speed of the first servo motor SM1 is increased in the control panel, the pulse output frequency of the PLC output port Y0 will increase, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will increase, the speed of the first servo motor SM1 driven by the first servo driver KQ1 will increase, the speed signal output by the first output port MO1 of the first servo driver KQ1 will increase, the speed signal received by the speed input port VLA on the second servo driver KQ2 will increase, and the speed of the second servo motor SM2 driven by the second servo driver KQ2 will also increase; when the running direction of the first servo motor SM1 is changed in the control panel, the speed value output on the first output port MO1 of the first servo driver KQ1 will change from a positive value to a negative value, the speed input signal VLA received by the second servo driver KQ2 will be a negative value, and the direction of the second servo motor SM2 driven by the second servo driver KQ2 will change.

[0031] When the operating torque of the first servo motor SM1 decreases, the torque signal collected by the first servo driver KQ1 becomes smaller, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also decrease, the torque signal sent by the first servo driver KQ1 to the second servo driver KQ2 will also become smaller, the torque signal received by the torque input port TC of the second servo driver KQ2 will also become smaller, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also decrease.

[0032] When the operating torque of the first servo motor SM1 increases, the torque signal collected by the first servo driver KQ1 becomes larger, the torque signal output by the second output port MO2 of KQ1 of the first servo driver will also increase, the torque signal received by the torque input port TC of the second servo driver KQ2 will also become larger, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also increase.

[0033] Gear transmission is adopted between the dials of the main engine of the knitting machine. When the knitting machine runs continuously and normally, the gear transmission speed between the dials of the main engine of the knitting machine is constant, each servo motor is evenly stressed and has a stable speed, thus ensuring the servo accuracy of the knitting machine speed driven by the multi-stage servo motor.

[0034] However, during the operation of the braiding machine, it is inevitable that there are gaps of varying sizes between the transmission gears, as well as changes in rotational resistance caused by load changes. It is difficult to achieve synchronous operation of multiple servo motors using multi-stage servo motors as driving power, and some servo motors may be subjected to excessive force, some servo motors may be subjected to insufficient force, and some servo motors may regenerate. A multi-servo motor synchronous control system and control method, the first servo driver KQ1 adopts pulse control, which fully ensures that the speed of the first servo driver KQ1 runs in a very stable state, and the remaining servo motors adopt speed plus torque control, which can not only ensure the stability of the speed of the first servo driver KQ1, but also automatically adjust and make up for the intervals between the transmission gears, automatically balance the force of each servo motor, and ensure uniform force between each servo motor; fully ensure the synchronization accuracy of multiple servo motors driving a braiding machine host at the same time.

[0035] The invention solves the problems that the main machine of the existing large-scale knitting machine is difficult to run at a low speed and multiple servo motors cannot run synchronously, thereby achieving the purpose of the invention.

[0036] Advantages: It can ensure that the motor of the knitting machine runs at a speed as low as 10 rpm, and the yarn can be replaced without stopping the machine, which is convenient for the knitting operator to debug the machine at a low speed and try to knit the product. When the knitting sample is satisfactory, the motor speed of the knitting machine is adjusted to the rated speed for normal operation, which is convenient for the knitting machine user, stabilizes and improves the quality and output of the product, and reduces the waste of trial knitting products. It is easy to operate, reduces the waste of knitting products, and increases the knitting speed of the machine. On a machine running at a low speed, the knitting speed can be easily increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural block diagram of the braiding machine control system of the present invention.

[0038] FIG. 2 is a control flow chart of a knitting machine according to the present invention.

[0039] Figure 3 It is a diagram of the PLC input and output signals of the knitting machine of the present invention.

[0040] Figure 4 This is a control schematic diagram of two servo drivers of the braiding machine of the present invention.

[0041] Figure 5 This is a control schematic diagram of three servo drivers of the braiding machine of the present invention.

[0042] In the figure, SB1, the external start button of the knitting machine; SB2, the external stop button of the knitting machine; S1, the external emergency stop button of the knitting machine; ALM1, KQ1 alarm output signal port; ALM2, KQ2 alarm output signal port; ALM3, KQ3 alarm output signal port;

[0043] PP, KQ1 pulse input port; NP, KQ1 direction signal input port; MO1, KQ1 first output port; VLA, KQ2 speed input port; MO2, KQ1 second output port; TC, KQ2 torque input port; RS1, KQ2 start signal port; VLA1, KQ3 speed input port; TC1, KQ3 torque input port; SON, KQ1 enable port; SON1, KQ2 enable port; SON3, KQ3 enable port; RS2, KQ3 start signal port;

[0044] Q1, the main power switch of the line; Q2, the power switch of the first servo driver KQ1; Q3, the power switch of the second servo driver KQ2; Q4, the power switch of the third servo driver KQ3; KQ1, the first servo driver; KQ2, the second servo driver; KQ3, the third servo driver; SM1, the first servo motor; SM2, the second servo motor; SM3, the third servo motor. DETAILED DESCRIPTION

[0045] Embodiment 1: The synchronous control of multiple servo motors of a knitting machine host of the present invention includes a servo motor synchronous control system and a control method based on the servo motor synchronous control system.

[0046] The servo motor synchronous control system includes: a control panel, a PLC and a servo drive device. The control panel is connected to the input end of the PLC to set the internal parameters of the PLC; the output end of the PLC is connected to the servo drive device to control the servo drive device to drive the operation and operation speed of the knitting machine.

[0047] The servo drive device has at least two sets with the same structure, including: a servo drive and a servo motor, wherein the output end of the servo drive is connected to the servo motor to form a set of servo drive devices, and the servo drive drives the servo motor to operate;

[0048] The two servo drive devices include: a first servo driver KQ1, a second servo driver KQ2, a first servo motor SM1 and a second servo motor SM2;

[0049] The control panel is connected to the input end of the PLC, and is used to set the internal parameters of the PLC and control the operation and operating speed of the servo motor; the output end of the PLC is connected to the input end of the first servo driver KQ1 and the second servo driver KQ2, and the output ends of the first servo driver KQ1 and the second servo driver KQ2 are respectively connected to the first servo motor SM1 and the second servo motor SM2, and the PLC controls the operation of the first servo motor SM1 and the second servo motor SM2 respectively through the first servo driver KQ1 and the second servo driver KQ2; the first servo motor SM1 and the second servo motor SM2 are meshed with the main engine dial gear through the motor transmission gear to drive the knitting machine main engine to operate.

[0050] The PLC includes input port X0, input port X1, input port X2, input port X3, input port X4, output port Y0 and output port Y2; output port Y6 and output port Y7, etc.

[0051] PLC input port X0 is the start input signal port, which is connected to the external start button SB1 of the knitting machine; PLC input port X1 is the stop input signal port, which is connected to the external stop button SB2 of the knitting machine; PLC input port X2 is the emergency stop signal port, which is connected to the external emergency stop button S1 of the knitting machine; PLC input port X3 is the alarm signal port of the first servo driver KQ1, which is connected to the KQ1 alarm output signal port ALM1, and is used to detect whether the first servo driver KQ1 has an alarm output; PLC input port X4 is the alarm port of the second servo driver KQ2, which is connected to the KQ2 alarm output signal port ALM2, and is used to detect whether the second servo driver KQ2 has an alarm output.

[0052] PLC output port Y0 is a high-speed pulse output port, which is connected to KQ1 pulse input port PP; PLC output port Y0 sends a pulse signal to KQ1 pulse input port PP to control the running speed of the first servo motor SM1; PLC output port Y2 is connected to the direction signal input port NP of the first servo driver KQ1, and PLC output port Y2 outputs a direction signal to KQ1 direction signal input port NP to control the running direction of the first servo motor SM1.

[0053] The first output port MO1 of KQ1 of the first servo driver is connected to the speed input port VLA of KQ2 of the second servo driver. The first output port MO1 of KQ1 outputs the speed signal of the first servo motor SM1, and outputs the real-time value of the speed of the first servo motor SM1 to the speed input port VLA of KQ2 to control the speed and direction of the second servo motor SM2.

[0054] At the same time, the second output port MO2 of the first servo driver KQ1 is connected to the torque input port TC of the second servo driver KQ2, and the second output port MO2 of KQ1 outputs the current value of the torque of the first servo motor SM1 to the torque input port TC of KQ2 to control the operating torque of the second servo motor SM2;

[0055] The second servo driver KQ2 controls the operation of the second servo motor SM2 according to the speed and torque signals received from the first servo driver KQ1.

[0056] The PLC is a Mitsubishi PLC, or a PLC from another manufacturer with a high-speed pulse output port.

[0057] The servo driver is a servo driver with two multifunctional output ports and is a commercially available product.

[0058] A control method based on a servo motor synchronous control system: the first servo driver KQ1 directly sends the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2, and the second servo driver KQ2 controls the operation of the second servo motor SM2 according to the received speed and torque signals.

[0059] The specific steps are as follows:

[0060] Step 1: Check whether the circuit wiring is correct. After the inspection is completed, connect the power supply, power on the machine, and complete the PLC system initialization self-test. After the PLC detects that there is no fault or alarm information in the external electrical appliances;

[0061] Press the external start button SB1 of the knitting machine, the PLC output port Y6 outputs an external enable signal to the first servo driver KQ1 and the second servo driver KQ2, then the PLC pulse output port Y0 outputs a pulse signal to the KQ1 pulse input port PP to control the running speed of the first servo driver KQ1, the PLC output port Y2 outputs a running direction signal to the KQ1 direction signal input port NP, and at the same time the PLC Y7 output port outputs a start signal to the KQ2 start signal port RS1 of the second servo driver, the first servo driver KQ1 and the second servo driver KQ2 run at the same time, the first servo driver KQ1 and the second servo driver KQ2 respectively drive the first servo motor SM1 and the second servo motor SM2 to run synchronously;

[0062] Step 2: Adjust the control panel to speed up or slow down the speed of the first servo motor SM1, and control the speed of the first servo motor SM1 and the second servo motor SM2 to speed up or slow down synchronously; the specific control method is as follows:

[0063] Step 2-1, when adjusting the control panel to speed up the speed of the first servo motor SM1, the PLC will automatically speed up the pulse output frequency of the output port Y0 after internal calculation, and the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will increase, and the speed of the first servo motor SM1 driven by the first servo driver KQ1 will be accelerated. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will increase, and the speed signal received by the speed input port VLA on the second servo driver KQ2 will also increase, and the speed of the second servo motor SM2 driven by the second servo driver KQ2 will be accelerated, thereby achieving synchronous speed-up with the first servo motor SM1.

[0064] Step 2-2, when adjusting the control panel to reduce the speed of the first servo motor SM1; the PLC will automatically reduce the pulse output frequency of the PLC output port Y0 after internal calculation. As the pulse frequency output by the PLC output port Y0 decreases, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will decrease, and the speed of the first servo motor SM1 will decrease. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will decrease, and the speed signal received by the speed input port VLA of the second servo driver KQ2 will decrease. The speed of the second servo motor SM2 controlled by the second servo driver KQ2 will also decrease, thereby achieving synchronous speed reduction with the first servo motor SM1.

[0065] Step 3: The servo driver controls the operation of the servo motor. When the load of the knitting machine changes, the operating torques of the first servo motor SM1 and the second servo motor SM2 will change with the change of the load of the knitting machine, and the control system will reduce the operating torque of the servo motor or increase the operating torque of the servo motor.

[0066] The first servo driver KQ1 detects the real-time torque signal of the first servo motor SM1, and the torque signal output by the second output port MO2 of the first servo driver KQ1 is given to the torque input port TC of the second servo driver KQ2. The second servo driver KQ2 controls the rotation torque of the second servo motor SM2 according to the received torque signal. The specific control method is as follows:

[0067] Step 3-1, when the load of the braiding machine decreases, the operating torque of the first servo motor SM1 will decrease, the torque signal collected by the first servo driver KQ1 will decrease, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also decrease, the torque signal received by the torque input port TC of the second servo driver KQ2 will also decrease, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also decrease;

[0068] Step 3-2, when the load of the braiding machine increases, the operating torque of the first servo motor SM1 increases, the torque signal collected by the first servo driver KQ1 becomes larger, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also increase, the torque signal received by the torque input port TC of KQ2 will also increase, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also increase.

[0069] This embodiment discloses a synchronous control system that controls two sets of servo drive devices to drive the knitting machine to operate normally, but is not limited to controlling two sets of servo drive devices to drive the knitting machine to operate normally.

[0070] Embodiment 2: This embodiment discloses a synchronous control system that controls no less than two sets of servo drive devices to drive the normal operation of the knitting machine. When the load of the knitting machine is too heavy and the two sets of servo drive devices cannot meet the normal operation of the machine, the synchronous control system of the present invention can be expanded to use three servo drive devices for synchronous operation, or expanded to use more sets of servo drive devices for synchronous control operation.

[0071] In this embodiment, only one synchronous control system controlling three sets of servo drive devices to drive the knitting machine to operate normally is taken as an example for explanation.

[0072] The first servo driver KQ1 sends the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2 and the third servo driver KQ3 simultaneously. The second servo driver KQ2 and the third servo driver KQ3 respectively control the operation of the second servo motor SM2 and the third servo motor SM3 according to the received speed and torque signals.

[0073] The alarm signal output port ALM3 of the third servo driver KQ3 is connected to the input port X5 of the PLC to receive the alarm output signal of the third servo driver KQ3. The enable port SON2 of the third servo driver KQ3 is connected to the output port Y6 of the PLC to receive the enable signal issued by the PLC, and the operation port RS2 of the third servo driver KQ3 is connected to the output port Y7 of the PLC to receive the operation signal issued by the PLC.

[0074] The speed input port VLA1 of the third servo driver KQ3 and the speed input port VLA of the second servo driver KQ2 are connected in parallel to the first output port MO1 of the first servo driver KQ1 for receiving the speed signal of the first servo driver KQ1. The torque input port TC1 of the third servo driver KQ3 and the torque input port TC of the second servo driver KQ2 are connected in parallel to the second output port MO2 of the first servo driver KQ1 for receiving the torque signal of the first servo driver KQ1.

[0075] A control method based on a servo motor synchronous control system: the first servo driver KQ1 sends the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2 and the third servo driver KQ3 at the same time, and the second servo driver KQ2 and the third servo driver KQ3 respectively control the operation of the second servo motor SM2 and the third servo motor SM3 according to the received speed and torque signals.

[0076] The specific steps are as follows:

[0077] Step 1: Check whether the circuit wiring is correct. After the inspection is completed, connect the power supply, power on the machine, and complete the PLC system initialization self-test. After the PLC detects that there is no fault or alarm information in the external electrical appliances;

[0078] Step 2: Adjust the control panel to speed up or slow down the speed of the first servo motor SM1, and control the speed of the first servo motor SM1, the second servo motor SM2 and the third servo motor SM3 to speed up or slow down synchronously; the specific control method is as follows:

[0079] Step 2-1, when adjusting the control panel to speed up the speed of the first servo motor SM1, the PLC will automatically speed up the pulse output frequency of the output port Y0 after internal calculation, and the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will increase, and the speed of the first servo motor SM1 driven by the first servo driver KQ1 will be accelerated. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will increase, and the speed signals received by the speed input port VLA on the second servo driver KQ2 and the speed input port VLA1 on the third servo driver KQ3 will increase. The speeds of the second servo motor SM2 and the third servo motor SM3 driven by the second servo driver KQ2 and the third servo driver KQ3 will be accelerated at the same time, thereby achieving synchronous speed-up with the first servo motor SM1.

[0080] Step 2-2, when adjusting the control panel to reduce the speed of the first servo motor SM1; the PLC will automatically reduce the pulse output frequency of the PLC output port Y0 after internal calculation. As the pulse frequency output by the PLC output port Y0 decreases, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will decrease, and the speed of the first servo motor SM1 will decrease. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will decrease, and the speed signals received by the speed input port VLA of the second servo driver KQ2 and the speed input port VLA1 of the third servo driver KQ3 will decrease. The speeds of the second servo motor SM2 and the third servo motor SM3 controlled by the second servo driver KQ2 and the third servo driver KQ3 will decrease at the same time, thereby achieving synchronous speed reduction with the first servo motor SM1.

[0081] Step 3: The servo driver controls the operation of the servo motor. When the load of the knitting machine changes, the operating torques of the first servo motor SM1, the second servo motor SM2 and the third servo motor SM3 will change with the change of the load of the knitting machine, and the control system will reduce the operating torque of the servo motor or increase the operating torque of the servo motor.

[0082] The first servo driver KQ1 detects the real-time torque signal of the first servo motor SM1, and the torque signal output by the second output port MO2 of the first servo driver KQ1 is simultaneously given to the torque input port TC of the second servo driver KQ2 and the torque input port TC1 of the third servo driver KQ3. The second servo driver KQ2 and the third servo driver KQ3 control the rotation torque of the second servo motor SM2 and the third servo motor SM3 respectively according to the received torque signal; the specific control method is as follows:

[0083] Step 3-1, when the load of the braiding machine decreases, the operating torque of the first servo motor SM1 will decrease, the torque signal collected by the first servo driver KQ1 will decrease, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also decrease, the torque signals received by the torque input port TC of the second servo driver KQ2 and the torque input port TC1 of the third servo driver KQ3 will decrease at the same time, and the operating torques of the second servo motor SM2 driven by the second servo driver KQ2 and the third servo motor SM3 driven by the third servo driver KQ3 will decrease at the same time;

[0084] Step 3-2, when the load of the braiding machine increases, the operating torque of the first servo motor SM1 increases, the torque signal collected by the first servo driver KQ1 becomes larger, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also increase, the torque signals received by the KQ2 torque input port TC and the KQ3 torque input port TC1 will increase at the same time, and the operating torques of the second servo motor SM2 driven by the second servo driver KQ2 and the third servo motor SM3 driven by the third servo driver KQ3 will increase at the same time.

Claims

1. A control method for a multi-servo motor synchronous control system of a knitting machine host, characterized in that: Control method: The first servo driver KQ1 directly sends the speed and torque signals of the first servo motor SM1 to the second servo driver KQ2, and the second servo driver KQ2 controls the operation of the second servo motor SM2 according to the received speed and torque signals; The specific steps are as follows: Step 1: Check whether the circuit wiring is correct. After the inspection is completed, connect the power supply, power on the machine, and complete the PLC system initialization self-test. After the PLC detects that there is no fault or alarm information in the external electrical appliances; Press the external start button SB1 of the knitting machine, the PLC output port Y6 outputs an external enable signal to the first servo driver KQ1 and the second servo driver KQ2, then the PLC pulse output port Y0 outputs a pulse signal to the KQ1 pulse input port PP to control the running speed of the first servo driver KQ1, the PLC output port Y2 outputs a running direction signal to the KQ1 direction signal input port NP, and at the same time the PLC Y7 output port outputs a start signal to the KQ2 start signal port RS1 of the second servo driver, the first servo driver KQ1 and the second servo driver KQ2 run at the same time, the first servo driver KQ1 and the second servo driver KQ2 respectively drive the first servo motor SM1 and the second servo motor SM2 to run synchronously; Step 2: Adjust the control panel to speed up or slow down the speed of the first servo motor SM1, and control the speeds of the first servo motor SM1 and the second servo motor SM2 to speed up or slow down synchronously; Step 3: The servo driver controls the operation of the servo motor. When the load of the knitting machine changes, the operating torques of the first servo motor SM1 and the second servo motor SM2 will change with the change of the load of the knitting machine, and the control system will reduce the operating torque of the servo motor or increase the operating torque of the servo motor. The first servo driver KQ1 detects the real-time torque signal of the first servo motor SM1, and the torque signal output by the second output port MO2 of the first servo driver KQ1 is given to the torque input port TC of the second servo driver KQ2, and the second servo driver KQ2 controls the rotation torque of the second servo motor SM2 according to the received torque signal; In step 2, the specific control method is as follows: Step 2-1, when adjusting the control panel to speed up the speed of the first servo motor SM1; the PLC will automatically speed up the pulse output frequency of the output port Y0 after internal calculation, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will increase, and the speed of the first servo motor SM1 driven by the first servo driver KQ1 will be accelerated. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will increase, and the speed signal received by the speed input port VLA on the second servo driver KQ2 will also increase, and the speed of the second servo motor SM2 driven by the second servo driver KQ2 will be accelerated, so as to achieve synchronous speed-up with the first servo motor SM1; Step 2-2, when adjusting the control panel to reduce the speed of the first servo motor SM1; the PLC will automatically reduce the pulse output frequency of the PLC output port Y0 after internal calculation. As the pulse frequency output by the PLC output port Y0 decreases, the pulse frequency received by the pulse input port PP of the first servo driver KQ1 will decrease, and the speed of the first servo motor SM1 will decrease. At the same time, the speed signal output by the first output port MO1 of the first servo driver KQ1 will decrease, and the speed signal received by the speed input port VLA of the second servo driver KQ2 will decrease. The speed of the second servo motor SM2 controlled by the second servo driver KQ2 will also decrease, thereby achieving synchronous speed reduction with the first servo motor SM1. In step 3, the specific control method is as follows: Step 3-1, when the load of the braiding machine decreases, the operating torque of the first servo motor SM1 will decrease, the torque signal collected by the first servo driver KQ1 will decrease, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also decrease, the torque signal received by the torque input port TC of the second servo driver KQ2 will also decrease, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also decrease; Step 3-2, when the load of the braiding machine increases, the operating torque of the first servo motor SM1 increases, the torque signal collected by the first servo driver KQ1 becomes larger, the torque signal output by the second output port MO2 of the first servo driver KQ1 will also increase, the torque signal received by the torque input port TC of KQ2 will also increase, and the operating torque of the second servo motor SM2 driven by the second servo driver KQ2 will also increase.

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