A servo control system and control method for a special-shaped plug-in machine

Abstract

The present invention belongs to the field of special-shaped plug-in machine processing, and specifically relates to a servo control system and control method for a special-shaped plug-in machine. The method is divided into two stages. In the first stage, the displacement distance of the plug-in shaft and the pressure value of the processed material are divided into three motion trajectories for calibration; in the second stage, the plug-in shaft is controlled to always be placed in the set position through the real-time pressure adjustment algorithm of the pressure holding section, and the movement changes of the plug-in shaft are controlled in a segmented manner, and the external pressure sensor is closed-loop compensated and controlled. The pressure curve is displayed in real time, and the pressure value is directly collected into the servo controller. The real-time pressure adjustment algorithm integrated in the servo controller converts the pressure value into a position pulse signal in real time to control the rapid movement of the processing axis, and quickly adjusts the movement of the plug-in shaft, thereby avoiding the data communication delay problem caused by first transmitting the pressure detection value to the PC end and then controlling the pressure. The position and torque control changes are quickly switched inside the servo controller to improve the processing efficiency of the special-shaped plug-in machine and reduce the risk of damage to the processed parts.

Description

Technical Field

[0001] The present invention relates to the field of special-shaped plug-in machine processing, and in particular to a servo control system and a control method for a special-shaped plug-in machine. Background Art

[0002] Due to defects in the incoming workpiece, components and PCBs can be damaged during the machining process of special-shaped plug-in machines. Researchers both domestically and internationally have proposed various protection methods, including spring-feedback pressure adjustment on the plug-in axis and controller torque control of the plug-in axis. Generally speaking, existing technologies cannot simultaneously reduce the damage rate and improve machining efficiency. However, as manufacturers' demands for higher yields and greater production capacity continue to increase, meeting user needs through technological means has become an important solution.

[0003] For example, the Chinese patent application number is "201921320256.5" and the application name is "Plug-in Machine Plug-in Pressure Protection Device". The plug-in shaft is installed on the lifting seat and has the characteristics of floating up and down and rotating relative to the lifting seat. A pressure sensor is arranged on the upper end of the plug-in shaft. The pressure sensor feeds back the pressure signal to the control part of the plug-in machine to control the lifting of the lifting seat. When the plug-in encounters an obstacle, the buffer spring of the clamping claw contracts upward, generating spring resistance. The spring resistance is transmitted to the pressure sensor through the plug-in shaft. The pressure sensor feeds back the pressure signal to the PC end of the plug-in machine, and generates a pressure value on the device display. When the lifting seat continues to drive the plug-in shaft to descend, this pressure value gradually increases. When the set threshold is reached, the control part of the plug-in machine controls the lifting seat to stop the lifting seat from descending, thereby protecting the plug-in components and PCB boards and achieving overvoltage protection. It has the following defects:

[0004] (1) The above solution does not control the speed trajectory of the insertion machine's descent. When the machining axis descends at high speed and reaches the contact surface, a large pressure value will be generated. The elastic compression force of the spring will instantly reach its limit, causing damage to the device. Therefore, this solution cannot meet the requirements of high-speed processing.

[0005] (2) The above technical solution uses a spring as a force transmission device, which has elastic deformation and will affect the test accuracy. In addition, the spring will lose its elasticity after multiple compression and stretching, and it needs to be replaced regularly.

[0006] (3) In the above scheme, the pressure detection value is first transmitted to the PC and then the pressure is controlled by the PC, which causes data communication delay. Summary of the Invention

[0007] In response to the problem that the existing technology cannot simultaneously reduce the damage rate of processed parts and improve processing efficiency, the present invention proposes a servo control system and control method for a special-shaped plug-in machine. The method is divided into two stages. In the first stage, the displacement distance of the plug-in shaft and the pressure value of the processed material are divided into three motion trajectories for calibration; in the second stage, the plug-in shaft is controlled to always be placed in the set position through a real-time pressure adjustment algorithm in the pressure holding section. The movement changes of the plug-in shaft are controlled in a segmented manner, closed-loop compensation control is performed by an external pressure sensor, and the pressure curve is displayed in real time. The position and torque control changes are quickly switched inside the servo controller to improve the processing efficiency of the special-shaped plug-in machine and reduce the risk of damage to the processed parts.

[0008] The specific implementation contents of the present invention are as follows:

[0009] A servo control method for a special-shaped plug-in machine is divided into two stages. In the first stage, a vacuum elastic suction nozzle is installed on the plug-in shaft, and the displacement distance of the plug-in shaft and the pressure value of the processed material are divided into three sections for calibration to obtain three motion trajectories. In the second stage, based on the obtained three-segment motion trajectories, a real-time pressure adjustment algorithm of the pressure holding section is used to control the plug-in shaft to move to the target plug-in position.

[0010] In order to better implement the present invention, further, the first stage specifically includes the following steps:

[0011] Step A1: The servo motor receives the plug-in start signal from the servo controller and moves the plug-in shaft downward at the maximum acceleration, the highest speed, and the shortest time to obtain the first motion trajectory;

[0012] Step A2: When the plug-in axis is 2-3 mm away from the target plug-in position, the descending speed is switched to below 10 mm / s to obtain the second motion trajectory;

[0013] Step A3: When the plug-in axis is 0.5 mm away from the target plug-in position, the data of the pressure sensor is cleared to obtain the third motion trajectory.

[0014] In order to better implement the present invention, further, the second stage specifically includes the following steps:

[0015] Step B1: Obtain the pressure value between the processed material and the PCB board collected by the pressure sensor, and output the pressure value to the servo controller through the RS485 interface;

[0016] Step B2: The servo controller uses the real-time pressure adjustment algorithm in the pressure holding stage to convert the pressure value obtained from the pressure sensor into a pulse equivalent δ for position control by the servo controller, and calculates the number of pulses D;

[0017] Step B3: The servo controller controls the plug-in axis to move to the target plug-in position according to the calculated pulse number D.

[0018] The servo control method for a special-shaped insertion machine according to claim 3, wherein step B2 specifically comprises the following steps:

[0019] Step B21: The servo controller receives the first pressure value F1 generated by the contact surface between the workpiece and the PCB, starts timing, reads the current servo motor encoder feedback position X1, and records the position X1 as the initial value;

[0020] Step B22: The servo controller receives the second pressure value F2 of the contact surface between the workpiece and the PCB, stops timing to obtain the detection time t, reads the current servo motor encoder feedback position X2, and calculates the current acceleration a of the servo controller;

[0021] Step B23: Calculate the screw speed v of the screw between the servo motor and the pressure sensor based on the detection time t and acceleration a obtained in step B22;

[0022] Step B24: Calculate the screw horizontal thrust Q based on the pressure value F1 obtained in step B21, the pressure value F2 obtained in step B2, and the screw thread inclination angle;

[0023] Step B25: Calculate the screw torque T based on the screw horizontal thrust Q and the screw diameter d2 obtained in step B24;

[0024] Step B26: Calculate the screw speed n based on the screw torque T and the servo motor pole pair number P obtained in step B25;

[0025] Step B27: Calculate the screw lead S based on the screw speed v and the screw speed n obtained in step B23;

[0026] Step B28: Calculate the pulse equivalent δ based on the screw lead S and the servo motor angular resolution Rm obtained in step B27;

[0027] Step B29: Calculate the pulse number D based on the pulse equivalent δ obtained in step B28, the servo motor encoder feedback position X1 obtained in step B21, and the servo motor encoder feedback position X2 obtained in step B22.

[0028] In order to better implement the present invention, further, step B3 specifically includes the following steps:

[0029] Step B31: The servo controller controls the servo motor to move vertically to the position where the workpiece and the PCB first contact and generate a pressure value F1 according to the pulse number D obtained in step B2, and the servo controller outputs a vacuum release signal;

[0030] Step B32: The servo controller controls the elastic suction nozzle to generate pressure on the pressure sensor and the material being processed according to the vacuum release signal, and outputs a blowing signal;

[0031] Step B33: The servo controller switches the air pressure of the elastic nozzle to blowing according to the blowing signal, controls the plug-in axis to move to the target plug-in position, and outputs a plug-in completion signal.

[0032] In order to better realize the present invention, further, based on the above-mentioned servo control method of the special-shaped plug-in machine, a servo control system of the special-shaped plug-in machine is proposed, which is connected to the processed material and is used to process the PCB board, including a servo controller, a servo motor, a pressure sensor, and a vacuum elastic suction nozzle;

[0033] The servo motor, pressure sensor and vacuum nozzle are connected in sequence to form a plug-in shaft;

[0034] The servo controller is connected to the servo motor and the pressure sensor respectively through cables;

[0035] The servo controller is used to calibrate the displacement distance of the plug-in shaft and the pressure value of the processed material into three motion trajectories, and is used to embed a real-time pressure adjustment algorithm in the pressure holding section to control the plug-in shaft to always be placed in the set position.

[0036] In order to better implement the present invention, further, the servo controller includes a position control module, a speed control module, and a torque control module;

[0037] The position control module is used to receive the plug-in start signal sent by the servo controller, and move the plug-in shaft downward at the maximum acceleration, the highest speed, and the shortest time to obtain the first motion trajectory;

[0038] The speed control module is used to switch the speed to less than 10 mm / s when the plug-in axis is 2-3 mm away from the target plug-in position, thereby obtaining a second motion trajectory;

[0039] The torque control module is used to clear the data received from the pressure sensor when the plug-in axis is 0.5 mm away from the target plug-in position to obtain the third motion trajectory.

[0040] The present invention has the following beneficial effects:

[0041] (1) The present invention increases the vacuum elastic suction nozzle and pressure sensor on the plug-in shaft, detects the pressure value change in real time and feeds it back to the servo controller, adopts segmented control of the plug-in shaft movement change, performs closed-loop compensation control through an external pressure sensor, and displays the pressure curve in real time, thereby improving the processing efficiency of the special-shaped plug-in machine and reducing the risk of damage to the workpiece processed by the special-shaped plug-in machine.

[0042] (2) The present invention divides the descent of the plug-in shaft into three motion trajectories and marks them, that is, it adds a speed trajectory forward control function. During high-speed processing, the servo controller can make a forward planning of the motion trajectory speed based on the position control module before the plug-in shaft descends to the contact surface of the PCB board, thereby avoiding the huge impact force generated at the moment when the plug-in shaft descends at high speed to the contact surface of the PCB board during material processing.

[0043] (3) The present invention sets a vacuum suction nozzle on the plug-in shaft, uses air pressure as a force transmission device, and uses the air pressure itself to be adjusted to a constant value, thereby solving the problem of the elastic deformation of the spring itself when using the spring as a force transmission device, which affects the test accuracy, and reduces the influence of external mechanical errors on the test accuracy.

[0044] (4) The present invention directly collects the pressure value into the servo controller. The real-time pressure adjustment algorithm integrated in the servo controller converts the pressure value into a position pulse signal in real time to control the rapid movement of the processing axis. The self-developed pressure and position control conversion algorithm is used to quickly adjust the movement of the plug-in axis, completely avoiding the data communication delay problem caused by first transmitting the pressure detection value to the PC end and then controlling the pressure through the PC end. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a connection block diagram of the servo control method for the special-shaped plug-in machine proposed by the present invention;

[0046] Figure 2 This is a structural diagram of the servo control method for a special-shaped plug-in machine proposed by the present invention;

[0047] Figure 3 This is a schematic diagram of the screw position structure of the present invention;

[0048] Figure 4 It is a schematic diagram of the processing effect of the present invention;

[0049] Figure 5 This is a schematic diagram of the motion process control of the present invention;

[0050] Among them, 1. Servo controller, 2. Servo motor, 3. Pressure sensor, 4. Vacuum elastic nozzle, 5. Processed material, 6. PCB board, 7. Screw, 8. Cable. DETAILED DESCRIPTION

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technical personnel in this field without making creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0053] Example 1:

[0054] This embodiment proposes a servo control method for a special-shaped plug-in machine, which is divided into two stages. In the first stage, a vacuum elastic suction nozzle 4 is installed on the plug-in shaft, and the displacement distance of the plug-in shaft and the pressure value of the processed material 5 are divided into three sections for calibration to obtain three motion trajectories; in the second stage, based on the obtained three-segment motion trajectories, the pressure holding section real-time adjustment algorithm inside the servo controller 1 is used to control the plug-in shaft to move to the target plug-in position.

[0055] Working principle: This embodiment adds a vacuum elastic suction nozzle 4 and a pressure sensor 3 to the plug-in shaft to detect the pressure value changes in real time and feed them back to the servo controller 1. It adopts a segmented control method to control the movement changes of the plug-in shaft, and uses closed-loop compensation control through the external pressure sensor 3. The pressure curve is displayed in real time, which improves the processing efficiency of the special-shaped plug-in machine and reduces the risk of damage to the processed parts of the special-shaped plug-in machine.

[0056] Example 2:

[0057] This embodiment describes the specific steps of the first stage based on the above embodiment 1.

[0058] Working principle: The first stage specifically includes the following steps:

[0059] Step A1: The servo motor 2 receives the plug-in start signal from the servo controller 1 and moves the plug-in shaft downward at the maximum acceleration, the highest speed, and the shortest time to obtain the first motion trajectory;

[0060] Step A2: When the plug-in axis is 2-3 mm away from the target plug-in position, the servo motor 2 receives the torque limit signal from the servo controller 1 and switches the descending speed to less than 10 mm / s, thereby obtaining the second motion trajectory;

[0061] Step A3: When the plug-in axis is 0.5 mm away from the target plug-in position, the servo motor 2 receives the position control signal from the servo controller 1, clears the data obtained from the pressure sensor 3, and obtains the third motion trajectory.

[0062] The rest of this embodiment is the same as that of the above-mentioned embodiment 1, and therefore will not be described in detail.

[0063] Example 3:

[0064] This embodiment describes the specific steps of the second stage based on any one of the above embodiments 1-2.

[0065] Working Principle: The second stage specifically includes the following steps:

[0066] Step B1: obtaining the pressure value between the workpiece 5 and the contact surface of the PCB board 6 collected by the pressure sensor 3, and outputting the pressure value to the servo controller 1 through the RS485 interface;

[0067] Step B2: The servo controller 1 uses the real-time pressure adjustment algorithm in the pressure holding period to convert the pressure value obtained from the pressure sensor 3 into a pulse equivalent δ for position control by the servo controller 1 and calculate the number of pulses D;

[0068] Step B3: The servo controller 1 controls the plug-in axis to move to the target plug-in position according to the calculated pulse number D.

[0069] The step B2 specifically includes the following steps:

[0070] Step B21: The servo controller 1 receives the first pressure value F1 generated between the workpiece 5 and the contact surface of the PCB board 6, starts timing, reads the current servo motor encoder feedback position X1, and records the position X1 as the initial value;

[0071] Step B22: The servo controller 1 receives the second pressure value F2 generated between the workpiece 5 and the contact surface of the PCB board 6, stops timing to obtain the detection time t, reads the current servo motor encoder feedback position X2, and calculates the current acceleration a of the servo controller 1;

[0072] Step B23: Calculate the screw speed v of the screw 7 between the servo motor 2 and the pressure sensor 3 based on the detection time t and the acceleration a obtained in step B22;

[0073] Step B24: Calculate the screw horizontal thrust Q based on the pressure value F1 obtained in step B21, the pressure value F2 obtained in step B2, and the screw thread inclination angle;

[0074] Step B25: Calculate the screw torque T based on the screw horizontal thrust Q and the screw diameter d2 obtained in step B24;

[0075] Step B26: Calculate the screw speed n based on the screw torque T and the servo motor pole pair number P obtained in step B25;

[0076] Step B27: Calculate the screw lead S based on the screw speed v and the screw speed n obtained in step B23;

[0077] Step B28: Calculate the pulse equivalent δ based on the screw lead S and the servo motor angular resolution Rm obtained in step B27;

[0078] Step B29: Calculate the pulse number D based on the pulse equivalent δ obtained in step B28, the servo motor encoder feedback position X1 obtained in step B21, and the servo motor encoder feedback position X2 obtained in step B22.

[0079] The step B3 specifically includes the following steps:

[0080] Step B31: The servo controller 1 controls the servo motor 2 to move vertically to the position where the workpiece 5 and the PCB 6 first contact and generate a pressure value F1 according to the pulse number D obtained in step B2, and the servo controller 1 outputs a vacuum release signal;

[0081] Step B32: The servo controller 1 controls the vacuum elastic suction nozzle 4 to generate pressure on the pressure sensor 3 and the processed material 5 according to the vacuum release signal, and outputs a blowing signal;

[0082] Step B33: The servo controller 1 switches the air pressure of the vacuum elastic nozzle 4 to blowing according to the blowing signal, controls the plug-in axis to move to the target plug-in position, and outputs a plug-in completion signal.

[0083] The rest of this embodiment is the same as any of the above embodiments 1-2, so it will not be repeated here.

[0084] Example 4:

[0085] This embodiment is based on any one of the above embodiments 1-3. Figure 1 、 Figure 2 As shown, a servo control system for a special-shaped plug-in machine is proposed, which is connected to a workpiece 5 and is used to process a PCB board 6, including a servo controller 1, a servo motor 2, a pressure sensor 3, and a vacuum elastic nozzle 4;

[0086] The servo motor 2, the pressure sensor 3, and the vacuum elastic nozzle 4 are connected in sequence to form a plug-in shaft;

[0087] The servo controller 1 is connected to the servo motor 2 and the pressure sensor 3 respectively through cables 8;

[0088] The servo controller 1 is used to calibrate the displacement distance of the plug-in axis and the pressure value of the processed material 5 into three motion trajectories, and is used to embed a real-time pressure adjustment algorithm in the pressure holding section to control the plug-in axis to move to the target plug-in position.

[0089] Working principle: The servo controller 1 proposed in this embodiment includes a speed control module, a torque control module, and a position control module;

[0090] The speed control module is used to receive the plug-in start signal and move the plug-in shaft downward at the maximum acceleration, the highest speed and the shortest time to obtain the first motion trajectory;

[0091] The torque control module is used to receive the torque limit signal and switch the speed to a decrease of less than 10 mm / s when the plug-in shaft is 2-3 mm away from the target plug-in position, thereby obtaining a second motion trajectory;

[0092] The position control module is used to receive the position control signal, and when the plug-in axis is 0.5 mm away from the target plug-in position, clear the data received from the pressure sensor 3 to obtain the third motion trajectory.

[0093] The rest of this embodiment is the same as any of the above embodiments 1-3, so it will not be repeated here.

[0094] Example 5:

[0095] This embodiment is based on any one of the above embodiments 1-4. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown, a specific embodiment is used to describe in detail the process of improving processing efficiency by the servo control system.

[0096] Working principle: This embodiment proposes a method and device for solving the problem of not damaging electronic components and PCB boards while ensuring that processing efficiency is not affected when processing plug-in electronic components on a special-shaped plug-in machine. The principle is to add a vacuum elastic suction nozzle 4 and a pressure sensing device to the plug-in shaft of the equipment. This embodiment takes the pressure sensor 3 as an example, and detects the pressure value change in real time and feeds it back to the servo controller 1. The position and torque control changes are quickly switched inside the servo controller 1 to improve the processing efficiency of the plug-in machine and reduce the risk of damage to the workpiece; the movement changes of the plug-in shaft are controlled in a segmented manner, and the external pressure sensor 3 is closed-loop compensated for the control, and the pressure curve is displayed in real time.

[0097] Damage to components and PCBs 6 can occur during the machining of special-shaped plug-in machines due to defects in the workpiece material 5. Currently, methods include adding spring feedback pressure adjustment to the plug-in axis and using a controller with torque control. Overall, existing technologies cannot simultaneously reduce the damage rate and improve machining efficiency. However, as manufacturers' demands for higher yields and greater production capacity continue to increase, meeting user needs through technological means has become a crucial solution.

[0098] When the position given quantity, i.e. the pulse signal input, changes arbitrarily, the controlled quantity, i.e. the output quantity, quickly and accurately reproduces the change of the given quantity. This type of servo system is usually called a servo control system for controlling the position; the pressure sensor 3 inputs the analog pressure value into the servo controller 1, and the servo controller 1 converts the analog pressure value into a pulse signal inside the servo controller 1 and then controls the controlled quantity to quickly and accurately reproduce the change of the given quantity.

[0099] Control process description:

[0100] This embodiment divides the control process into two parts. The first part is based on the forward planning of the position pattern motion trajectory speed. The second part is the pressure closed loop real-time adjustment of the plug-in axis position when the component contacts the processing surface.

[0101] The workflow of the forward planning of the position mode motion trajectory speed is as follows:

[0102] The servo controller 1 controls the servo motor 2 to drive the plug-in shaft to move up and down to perform the initial calibration of the plug-in displacement distance and the pressure value that the processed material 5 can withstand, and the calibration displacement is divided into three motion trajectories;

[0103] In the first stage, the plug-in axis moves downward with the maximum acceleration, the highest speed and the shortest time, so that the positioning impact can be completed in advance;

[0104] The second section is opened 2-3 mm before the target plug-in position, and the speed is lowered at a low speed, that is, less than 10 mm / s, and the torque limit mode is automatically switched. The torque limit mode prevents the collision from happening in advance by making the servo controller 1 output a constant torque value in the specified path section;

[0105] The third stage is opened about 0.5mm before the target plug-in position, switching the torque limit mode to the position control mode. After the data of the received pressure sensor 3 is cleared, the pressure closed-loop control is started to prevent the collision pressure peak at the moment of contact at a lower speed.

[0106] The workflow for adjusting the plug-in axis position in real time through a pressure closed loop is as follows:

[0107] Impact force is generated at the moment of contact, and the vacuum elastic suction nozzle 4 generates pressure in both upward and downward directions;

[0108] The air pressure reversal is to transmit the pressure generated on the contact surface between the processed material 5 and the PCB board 6 to the pressure sensor 3 through the air pressure after blowing;

[0109] The pressure sensor 3 on the plug-in shaft obtains the pressure value between the contact surface of the processed material 5 and the PCB board 6, and transmits the pressure value back to the servo controller 1 through the RS485 communication method. The servo controller 1 then uses the real-time pressure adjustment algorithm of the pressure holding period to control the plug-in shaft to place the processed material 5 in the appropriate position. At the same time, an upper limit threshold is set for the pressure value. If it exceeds the upper limit, an alarm will be immediately generated at the back end to prevent the servo controller 1 itself from causing a runaway phenomenon and protect the processed material 5 from damage. This stage is called the pressure holding period.

[0110] Algorithm Description:

[0111] Real-time pressure adjustment algorithm in the pressure holding stage:

[0112] Algorithm principle:

[0113] The pressure value obtained from the pressure sensor 3 is converted into a pulse quantity for position control by the servo controller 1, thereby completing the closed-loop control of the external pressure sensor 3 and the servo controller 1, ensuring that the special-shaped insertion machine is in a pressure-maintaining state after the processed material 5 reaches the contact surface with the PCB board 6.

[0114] Specific steps of the algorithm:

[0115] After the servo controller 1 collects the first pressure value F1 between the material and the contact surface, it starts timing and simultaneously reads the current servo motor encoder feedback position X1 and records it as the initial value; it waits for the second pressure F2. The first and second pressure values ​​are both the pressure values ​​generated by the material and the contact surface, of which the second pressure value is the pressure that the vacuum nozzle continuously blows to the maximum deformation that the material can withstand during the initial calibration.

[0116] When the calibrated pressure value F2 is detected, the timing is stopped to obtain the time t, the current servo motor encoder feedback position X2, and the servo controller records the current acceleration a;

[0117] The above parameters are:

[0118] The relationship between the linear velocity v of the screw and the pressure detection time t and acceleration a is:

[0119] v=a / t

[0120] The relationship between the screw horizontal thrust Q and the detection pressure values ​​F2 and F1:

[0121] Q=(F2-F1)*tanλ

[0122] Where: Q is the horizontal thrust; λ is the inclination angle of the screw thread.

[0123] The relationship between the screw torque T and the horizontal thrust Q:

[0124] T=Q*d2 / 2

[0125] Where: d2 is the screw diameter.

[0126] The relationship between the screw speed n and the screw torque T is:

[0127] n=9549*P / T

[0128] Where: P is the number of motor pole pairs.

[0129] The relationship between the screw lead S and the screw speed n is:

[0130] S=v / n

[0131] The relationship between the pulse equivalent δ and the screw lead S is:

[0132] δ=S / R m

[0133] Where: R m is the motor angle resolution.

[0134] The relationship between the number of pulses D and the pulse equivalent δ is:

[0135] D=(X2-X1)*δ

[0136] After the pulse number D is calculated, this value is applied to the servo motor to control the plug-in axis to achieve the ideal processing state. The pulse number D is input into the servo control system. The servo control system is driven by the received pulses. The servo controller 1 controls the vertical position of the plug-in axis by adjusting it to the pressure F1 position where the material first contacts the PCB board 6, ensuring that the processed material 5 is not damaged.

[0137] like Figure 4The figure shows a schematic diagram of the plug-in axis in the unused state. State A is XY positioning after material removal, state B is Z-axis plug-in, state C is the automatic switching torque limit of the switching position servo, state D is the Z-axis top plate plug-in failure servo output abnormal signal Z-axis lift, state E is XY axis movement and material throwing, state F is the re-material positioning plug-in success, and state G is the Z-axis lift after the material is released. The prior art does not control the speed trajectory of the descending action of the special-shaped plug-in machine. When the plug-in axis descends at high speed and reaches the contact surface, a large pressure value will be generated, and the elastic compression force of the spring will instantly reach the limit, causing damage to the device. Therefore, this solution cannot meet the high-speed processing requirements; this embodiment adds a speed trajectory forward control function. During high-speed processing, the servo controller 1 can perform position mode motion trajectory speed forward planning for the stage before the plug-in axis descends to the contact surface between the PCB board 6, thereby reducing the pressure value generated on the contact surface when the plug-in axis descends at high speed to prevent the plug-in axis from generating a huge impact force when it descends at high speed to the contact surface of the PCB board 6 when the material 5 is being processed;

[0138] like Figure 5 The figure shows a schematic diagram of the motion process control, where pulse A represents the impact force generated at the moment of contact, pulse B represents the upward and downward pressure generated by the elastic suction nozzle after the vacuum is released, and pulse C represents the pressure generated on the sensor and the material after the air pressure is reversed to blow air. In the prior art, springs are used as force transmission devices, which have their own elastic deformation, which can affect test accuracy. Furthermore, springs lose their elasticity after repeated compression and stretching, requiring regular replacement. This embodiment uses a vacuum elastic suction nozzle 4, which uses air pressure as a force transmission device. The air pressure itself can be adjusted to a constant value, thereby reducing the impact of external mechanical errors on test accuracy.

[0139] In existing solutions, pressure detection values ​​are first transmitted to the PC, where pressure is then controlled, resulting in data communication delays. This embodiment directly collects pressure values ​​into the servo controller 1. The servo controller 1 integrates a real-time pressure adjustment algorithm that converts the pressure values ​​into position pulse signals in real time to control the rapid movement of the machining axis. Using a proprietary pressure and position control conversion algorithm, the plug-in axis movement can be rapidly adjusted, completely avoiding data communication delays.

[0140] The rest of this embodiment is the same as any of the above embodiments 1-4, so it will not be repeated here.

[0141] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A servo control method for a special-shaped plug-in machine, characterized in that: The process is divided into two stages. In the first stage, a vacuum elastic nozzle is installed on the plug-in shaft. The displacement distance of the plug-in shaft and the pressure value of the processed material are divided into three sections for calibration to obtain three motion trajectories. In the second stage, based on the three obtained motion trajectories, the pressure holding section real-time adjustment algorithm inside the servo controller is used to control the plug-in shaft to move to the target plug-in position. The second phase includes: Step B1: Obtain the pressure value between the workpiece and the contact surface of the PCB board collected by the pressure sensor, and output the pressure value to the servo controller through the RS485 interface; Step B2: The servo controller uses the real-time pressure adjustment algorithm in the pressure holding stage to convert the pressure value obtained from the pressure sensor into a pulse equivalent δ for position control by the servo controller, and calculates the number of pulses D; Step B3: The servo controller controls the plug-in axis to move to the target plug-in position according to the calculated pulse number D; The step B2 comprises: Step B21: The servo controller receives the first pressure value F1 generated between the workpiece and the contact surface of the PCB, starts timing, reads the position X1 currently fed back by the servo motor encoder, and records the position X1 as the initial value; Step B22: The servo controller receives the second pressure value F2 generated between the workpiece and the contact surface of the PCB, stops timing to obtain the detection time t, reads the current position X2 fed back by the servo motor encoder, and calculates the current acceleration a of the servo controller; Step B23: Calculate the screw speed v of the screw between the servo motor and the pressure sensor based on the detection time t and acceleration a obtained in step B22; Step B24: Calculate the screw horizontal thrust Q based on the pressure value F1 obtained in step B21, the pressure value F2 obtained in step B22, and the screw thread inclination angle; Step B25: Calculate the screw torque T based on the screw horizontal thrust Q and the screw diameter d2 obtained in step B24; Step B26: Calculate the screw speed n based on the screw torque T and the servo motor pole pair number P obtained in step B25; Step B27: Calculate the screw lead S based on the screw speed v and the screw speed n obtained in step B23; Step B28: Calculate the pulse equivalent δ based on the screw lead S and the servo motor angular resolution Rm obtained in step B27; Step B29: Calculate the pulse number D based on the pulse equivalent δ obtained in step B28, the position X1 of the servo motor encoder feedback obtained in step B21, and the position X2 of the servo motor encoder feedback obtained in step B22.

2. A servo control method for a special-shaped insertion machine according to claim 1, characterized in that: The first stage specifically includes the following steps: Step A1: The servo motor (2) receives the plug-in start signal from the servo controller (1), and moves the plug-in shaft downward at the maximum acceleration, the highest speed, and the shortest time to obtain the first motion trajectory; Step A2: When the plug-in axis is 2-3 mm away from the target plug-in position, the servo motor (2) receives the torque limit signal from the servo controller (1) and switches the descending speed to less than 10 mm / s, thereby obtaining the second motion trajectory; Step A3: When the plug-in axis is 0.5 mm away from the target plug-in position, the servo motor (2) receives the position control signal from the servo controller (1), clears the data obtained from the pressure sensor (3), and obtains the third motion trajectory.

3. A servo control method for a special-shaped plug-in machine according to claim 1, characterized in that: The step B3 specifically includes the following steps: Step B31: The servo controller (1) controls the servo motor (2) to move in the vertical direction to a position where the workpiece (5) and the PCB (6) first come into contact with each other and generate a pressure value F1 according to the pulse number D obtained in step B2, and the servo controller (1) outputs a vacuum release signal; Step B32: The servo controller (1) controls the vacuum elastic suction nozzle (4) to generate pressure on the pressure sensor (3) and the processed material (5) according to the vacuum release signal, and outputs a blowing signal; Step B33: The servo controller (1) switches the air pressure of the vacuum elastic suction nozzle (4) to blowing according to the blowing signal, controls the plug-in axis to move to the target plug-in position, and outputs a plug-in completion signal.

4. A servo control system for a special-shaped plug-in machine, used to execute a servo control method for a special-shaped plug-in machine according to any one of claims 1 to 3; connected to a material to be processed (5), used to process a PCB board (6), characterized in that: It includes a servo controller (1), a servo motor (2), a pressure sensor (3), and a vacuum elastic suction nozzle (4); The servo motor (2), the pressure sensor (3), and the vacuum elastic suction nozzle (4) are connected in sequence to form a plug-in shaft; The servo controller (1) is connected to the servo motor (2) and the pressure sensor (3) respectively via cables (8); The servo controller (1) is used to calibrate the displacement distance of the plug-in shaft and the pressure value of the processed material (5) into three sections of motion trajectories, and is used to embed a real-time pressure adjustment algorithm in the pressure holding section to control the plug-in shaft to move to a target plug-in position.

5. A servo control system for a special-shaped insertion machine as claimed in claim 4, characterized in that: The servo controller (1) comprises a speed control module, a torque control module, and a position control module; The speed control module is used to receive the plug-in start signal and move the plug-in shaft downward at the maximum acceleration, the highest speed and the shortest time to obtain the first motion trajectory; The torque control module is used to receive the torque limit signal and switch the speed to a decrease of less than 10 mm / s when the plug-in shaft is 2-3 mm away from the target plug-in position, thereby obtaining a second motion trajectory; The position control module is used to receive the position control signal and clear the data received from the pressure sensor (3) when the plug-in axis is 0.5 mm away from the target plug-in position to obtain the third motion trajectory.

6. A servo control system for a special-shaped insertion machine as claimed in claim 4, characterized in that: The servo motor (2) is provided with a servo motor encoder; The servo motor encoder is used to feedback the current position of the servo motor (2).

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