Glass grinder based on PLC automation control

Abstract

The application discloses a kind of glass grinder based on PLC automation control, including three-axis motion mechanism, PLC controller, man-machine interface, servo drive assembly, grinding executive mechanism and communication unit;The grinding executive mechanism is installed in the output end of three-axis motion mechanism, the three-axis motion mechanism is electrically connected with servo drive assembly, and the servo drive assembly and man-machine interface are connected with PLC controller respectively by communication unit;The PLC controller is used to receive the defect position coordinates, grinding track parameters and grinding process parameters input by man-machine interface, and generates three-axis motion control instruction according to coordinates and parameters, drives servo drive assembly to drive three-axis motion mechanism and grinding executive mechanism, and performs automatic fixed-point grinding on glass cover plate defect position.The application uses PLC full-automatic control, completely replaces manual handheld grinding operation, a person can control multiple equipment simultaneously, significantly reduces labor intensity and labor cost.

Description

Technical Field

[0001] This invention relates to the field of glass grinding machine technology, specifically a glass grinding machine based on PLC automatic control. Background Technology

[0002] Currently, there are two main grinding technologies for glass covers of electronic products: 1. Full grinding solution, which involves grinding the entire glass cover to repair scratches on its surface; 2. Single-point grinding solution, which involves grinding a single point on the glass cover where the scratch is located to repair scratches.

[0003] For single-point grinding, the current mainstream approach is for workers to repeatedly grind the scratched area of ​​the glass cover using a handheld grinding tool until the scratch disappears. This method has the following two drawbacks: 1. The process requires repeated manual grinding over long periods of time, resulting in high labor costs, high work intensity for operators, and monotonous and tedious tasks, which fails to improve the operators' work skills.

[0004] 2. Manual grinding: Because the movements cannot be strictly followed according to the prescribed trajectory, the grinding area is uneven, resulting in inconsistent grinding depths on the glass and ultimately poor glass grinding.

[0005] Therefore, we propose a glass grinding machine based on PLC automatic control. Summary of the Invention

[0006] The purpose of this invention is to provide a glass grinding machine based on PLC automated control to solve the problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a glass grinding machine based on PLC automatic control, comprising a three-axis motion mechanism, a PLC controller, a human-machine interface, a servo drive component, a grinding execution mechanism, and a communication unit; The grinding actuator is installed at the output end of the three-axis motion mechanism. The three-axis motion mechanism is electrically connected to the servo drive component. The servo drive component and the human-machine interface are respectively connected to the PLC controller through a communication unit. The PLC controller is used to receive the defect location coordinates, grinding trajectory parameters, and grinding process parameters input from the human-machine interface, and generate three-axis motion control commands based on the coordinates and parameters to drive the servo drive component to drive the three-axis motion mechanism and the grinding execution mechanism to perform automated fixed-point grinding on the defect location of the glass cover plate.

[0008] Preferably, the three-axis motion mechanism adopts the motion mechanism of a three-axis carving and washing machine, and the grinding execution mechanism adopts a wool grinding head.

[0009] Preferably, the communication unit includes an Ethernet interface and a Modbus communication protocol stack. The human-machine interface and the PLC controller are physically connected via Ethernet, and data interaction of control commands, process parameters, and operating status is realized based on the Modbus protocol.

[0010] Preferably, the servo drive component includes a servo driver and a servo motor. The servo motor is equipped with an encoder, which is used to collect the actual position and speed information of the servo motor in real time and feed it back to the PLC controller. The PLC controller performs closed-loop regulation based on the PID algorithm, corrects the output pulse signal, and realizes the precise positioning and stable speed operation of the grinding actuator.

[0011] Preferably, the PLC controller includes a trajectory planning module, which includes a 5-point circle drawing algorithm unit. The 5-point circle drawing algorithm unit is used to automatically calculate and generate a continuous circular grinding trajectory based on the center coordinates and radius parameters input by the human-machine interface, and to map the trajectory to the PLC coordinate system, thereby driving the grinding actuator to perform cyclic grinding along the circular trajectory.

[0012] Preferably, the human-machine interface is used to input the XYZ three-axis coordinates of the defect location, the grinding speed ratio, and the grinding pressure parameters; to display the servo motor operating status, the real-time values ​​of the three-axis coordinates, the grinding progress, and system fault information; and to store multiple sets of grinding process parameters corresponding to different defect specifications.

[0013] Preferably, the PLC controller further includes a parameter calibration module, which is used to lock the current speed ratio and pressure parameters as the optimal process parameters when the transition between the grinding area and the non-grinding area is smooth and no visible grinding marks are observed from multiple angles.

[0014] A method for controlling a glass grinding machine includes the following steps: S1. Mark the location of scratches on the glass cover plate, control the three-axis motion mechanism through the human-machine interface to move the grinding actuator to the corresponding position of the defect, and record and save the XYZ three-axis coordinates. S2. Input the XYZ three-axis coordinates into the PLC controller and map them to the PLC coordinate system; S3. Input the grinding trajectory parameters and grinding process parameters to the PLC controller through the human-machine interface. The PLC controller generates a continuous grinding path according to the built-in trajectory algorithm. S4 and PLC controllers output high-speed pulse signals to the servo drive components, driving the grinding actuator to perform automated grinding according to the preset trajectory, speed and pressure. S5: The servo motor encoder provides real-time feedback of position and speed information, and the PLC controller performs closed-loop correction to ensure stable grinding trajectory and force. S6. After grinding is completed, the system is reset and waits for the next operation instruction.

[0015] Preferably, in step S3, the grinding trajectory parameters include the center coordinates and radius, and the PLC controller uses a 5-point circle drawing algorithm to generate a circular grinding trajectory; the grinding process parameters include grinding speed and grinding pressure, and the parameters are obtained through experimental calibration. The judgment criteria are: the grinding area has no uneven depth, no visible scratches, and a natural transition with the surrounding glass.

[0016] Preferably, the human-machine interface is connected to the PLC controller via Ethernet, and the Modbus communication protocol is used to complete the instruction issuance, parameter writing and status feedback; the closed-loop correction adopts the PID control algorithm, and the PLC controller compares the deviation between the set position and the actual position, and adjusts the number and frequency of output pulses in real time to eliminate positioning errors.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. It adopts PLC fully automatic control, completely replacing manual hand-held grinding operations. A single person can manage multiple machines at the same time, significantly reducing labor intensity and labor costs, and solving the problems of low efficiency and monotonous operation in traditional manual operation.

[0018] 2. Through servo motors, encoders, and PID closed-loop control, precise positioning of the XYZ axes is achieved; combined with a 5-point circle drawing algorithm, the trajectory is ensured to be uniform and stable, avoiding defects such as uneven grinding depth and rough edges caused by manual operation, and the yield rate is increased from 95% to 99%.

[0019] 3. Process parameters such as grinding trajectory, speed, and pressure can be preset, stored, and repeatedly recalled. The grinding effect of defects of the same specification is highly uniform and is not affected by the operator's technique or experience, making it suitable for batch repair operations.

[0020] 4. Based on the existing standard three-axis engraving and washing machine, the function can be realized by simply replacing the grinding wool head. There is no need to develop a completely new machine. The investment is low and the implementation is quick. It can be compatible with most glass cover plate defect grinding scenarios.

[0021] 5. The human-machine interface communicates with the PLC via Ethernet and Modbus protocols, ensuring stable and reliable data transmission. Parameter settings, coordinate positioning, and start / stop control are all completed visually on the interface, reducing the operational threshold and facilitating on-site use. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the glass grinding machine based on PLC automatic control according to the present invention; Figure 2 This is a block diagram of the control system principle of the grinding machine of the present invention; Figure 3 This is a schematic diagram of the three-axis motion mechanism and grinding execution mechanism of the present invention; Figure 4 This is a schematic diagram of the human-machine interface and PLC communication connection structure of the present invention; Figure 5 This is a schematic diagram of the grinding trajectory structure of the 5-point circle drawing algorithm of the present invention; Figure 6 This is a schematic diagram of the closed-loop control process of the servo motor in this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0024] Please see Figure 1-6 In this embodiment of the invention, a glass grinding machine based on PLC automated control includes a three-axis motion mechanism, a PLC controller, a human-machine interface, a servo drive component, a grinding execution mechanism, and a communication unit. The grinding actuator is installed at the output end of the three-axis motion mechanism. The three-axis motion mechanism is electrically connected to the servo drive component. The servo drive component and the human-machine interface are respectively connected to the PLC controller through a communication unit. The three-axis motion mechanism adopts the motion mechanism of a three-axis carving and washing machine, and the grinding actuator adopts a wool grinding head.

[0025] The PLC controller is used to receive the defect location coordinates, grinding trajectory parameters, and grinding process parameters input from the human-machine interface, and generate three-axis motion control commands based on the coordinates and parameters to drive the servo drive component to drive the three-axis motion mechanism and the grinding execution mechanism to perform automated fixed-point grinding on the defect location of the glass cover plate.

[0026] The communication unit includes an Ethernet interface and a Modbus communication protocol stack. The human-machine interface is physically connected to the PLC controller via Ethernet and realizes data interaction of control commands, process parameters, and operating status based on the Modbus protocol.

[0027] The servo drive component includes a servo driver and a servo motor. The servo motor is equipped with an encoder, which is used to collect the actual position and speed information of the servo motor in real time and feed it back to the PLC controller. The PLC controller performs closed-loop regulation based on the PID algorithm, corrects the output pulse signal, and realizes the precise positioning and stable speed operation of the grinding actuator.

[0028] The PLC controller includes a trajectory planning module, which includes a 5-point circle drawing algorithm unit. The 5-point circle drawing algorithm unit is used to automatically calculate and generate a continuous circular grinding trajectory based on the center coordinates and radius parameters input by the human-machine interface, and map the trajectory to the PLC coordinate system to drive the grinding actuator to grind cyclically along the circular trajectory.

[0029] The human-machine interface is used to input the XYZ three-axis coordinates of the defect location, the grinding speed ratio, and the grinding pressure parameters; to display the servo motor operating status, real-time values ​​of the three-axis coordinates, grinding progress, and system fault information; and to store multiple sets of grinding process parameters corresponding to different defect specifications.

[0030] The PLC controller also includes a parameter calibration module, which is used to lock the current speed ratio and pressure parameters as the optimal process parameters when the transition between the grinding area and the non-grinding area is smooth and no visible grinding marks are observed from multiple angles.

[0031] A method for controlling a glass grinding machine includes the following steps: S1. Mark the location of scratches on the glass cover plate, control the three-axis motion mechanism through the human-machine interface to move the grinding actuator to the corresponding position of the defect, and record and save the XYZ three-axis coordinates. S2. Input the XYZ three-axis coordinates into the PLC controller and map them to the PLC coordinate system; S3. Input the grinding trajectory parameters and grinding process parameters to the PLC controller through the human-machine interface. The PLC controller generates a continuous grinding path according to the built-in trajectory algorithm. S4 and PLC controllers output high-speed pulse signals to the servo drive components, driving the grinding actuator to perform automated grinding according to the preset trajectory, speed and pressure. S5: The servo motor encoder provides real-time feedback of position and speed information, and the PLC controller performs closed-loop correction to ensure stable grinding trajectory and force. S6. After grinding is completed, the system is reset and waits for the next operation instruction.

[0032] Preferably, in step S3, the grinding trajectory parameters include the center coordinates and radius, and the PLC controller uses a 5-point circle drawing algorithm to generate a circular grinding trajectory; the grinding process parameters include grinding speed and grinding pressure, and the parameters are obtained through experimental calibration. The judgment criteria are: the grinding area has no uneven depth, no visible scratches, and a natural transition with the surrounding glass.

[0033] Preferably, the human-machine interface is connected to the PLC controller via Ethernet, and the Modbus communication protocol is used to complete the instruction issuance, parameter writing and status feedback; the closed-loop correction adopts the PID control algorithm, and the PLC controller compares the deviation between the set position and the actual position, and adjusts the number and frequency of output pulses in real time to eliminate positioning errors.

[0034] "Using the human-machine interface and XYZ three-axis control module of the device, the grinding head is moved to the corresponding defect location on the glass": Communication between the HMI screen and the PLC: 1) Establish connection: The HMI screen and PLC are physically connected via Ethernet interface and the parameters are configured according to the Modbus communication protocol so that the two can recognize and communicate with each other.

[0035] 2) Data Interaction: The HMI (Human Machine Screen) packages the operator's input XYZ three-axis movement control commands and parameter settings into data frames according to the communication protocol format and sends them to the PLC. Simultaneously, the PLC also sends data such as the servo motor's operating status and system feedback information to the HMI for display.

[0036] 3) PLC processing of input signals Data decoding: After receiving the data frame sent by the human-machine screen, the PLC decodes it according to the communication protocol and converts it into a recognizable internal signal, such as digital or analog signal.

[0037] Logical judgment and processing: The PLC processes the decoded signals according to the preset logical relationships and control strategies in the program.

[0038] 4) PLC control of servo motors Pulse signal output: The PLC sends pulse signals to the servo driver via a high-speed pulse output interface. The number of pulses determines the motor's rotation angle or displacement, and the pulse frequency determines the motor's speed. A specific number and frequency of pulses control the grinding head to move precisely to a designated position.

[0039] 5) Feedback and closed-loop control Motor status feedback: The servo motor uses an encoder to monitor its actual position, speed, and other information in real time. This feedback information is transmitted to the PLC via the servo driver.

[0040] Closed-loop control adjustment: The PLC compares the received feedback information with the set value, calculates the deviation value, and then adjusts the output signal through a control algorithm (such as PID control) to reduce the deviation, so that the actual operating state of the servo motor is close to or reaches the set value, thereby achieving precise closed-loop control.

[0041] Position the grinding trajectory of the glass cover plate into the PLC coordinate system: The grinding trajectory was designed using the built-in trajectory algorithm function of the PLC.

[0042] Since the grinding method used in this study employs a circular drawing method, the 5-point circular drawing algorithm built into the PLC is utilized.

[0043] First, the operator writes the center and radius parameters into the PLC. Then, the PLC program provides the parameters required for the 5-point circle drawing method, enabling the grinding head to perform circle grinding along a preset trajectory.

[0044] The working principle of this invention is: The operator first marks the scratch / defect location on the glass cover plate, and then manually controls the three-axis motion mechanism through the human-machine interface to move the grinding head to the center point of the defect. The system automatically records the XYZ three-axis coordinates of the location and stores them in the PLC coordinate system to complete the precise positioning of the grinding target point.

[0045] The human-machine interface and the PLC controller communicate via Ethernet physical connection and Modbus protocol. The operator inputs the grinding trajectory parameters (center and radius) and process parameters (grinding speed and pressure) into the interface. The interface packages the instructions and parameters into data frames and sends them to the PLC. The PLC completes the decoding and logic processing.

[0046] The PLC has a built-in 5-point circle drawing algorithm unit that automatically calculates and generates a continuous and stable circular grinding trajectory based on the input center coordinates and radius, and maps the trajectory to a three-axis motion coordinate system to form a motion path that can be directly executed.

[0047] The PLC controls the servo driver through high-speed pulse output. The number of pulses determines the displacement, and the pulse frequency determines the rotation speed. The servo motor drives the three-axis motion mechanism and the wool grinding head to cyclically grind the defect location strictly according to the preset trajectory, speed, and pressure, without the need for manual intervention throughout the process.

[0048] The servo motor has a built-in encoder that collects the actual position and speed of the motor in real time and feeds it back to the PLC. The PLC compares the actual value with the set value and dynamically corrects the output pulse through the PID control algorithm to eliminate positioning deviation and motion error, ensuring uniform grinding trajectory, stable pressure and consistent depth.

[0049] During the grinding process, the PLC's parameter calibration module determines the grinding effect in real time: when the transition between the grinding area and the non-grinding area is smooth and no visible grinding marks are observed from multiple angles, the current speed and pressure are automatically locked as the optimal parameters to ensure consistency in batch operations.

[0050] After the preset number of grinding cycles or time is reached, the system automatically stops grinding, the three-axis motion mechanism resets, and waits for the next set of glass cover plate operation instructions. This allows a single person to operate multiple devices simultaneously for continuous operation.

[0051] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A glass grinding machine based on PLC automated control, characterized in that, It includes a three-axis motion mechanism, a PLC controller, a human-machine interface, servo drive components, a grinding actuator, and a communication unit; The grinding actuator is installed at the output end of the three-axis motion mechanism. The three-axis motion mechanism is electrically connected to the servo drive component. The servo drive component and the human-machine interface are respectively connected to the PLC controller through a communication unit. The PLC controller is used to receive the defect location coordinates, grinding trajectory parameters, and grinding process parameters input from the human-machine interface, and generate three-axis motion control commands based on the coordinates and parameters to drive the servo drive component to drive the three-axis motion mechanism and the grinding execution mechanism to perform automated fixed-point grinding on the defect location of the glass cover plate.

2. The glass grinding machine based on PLC automated control according to claim 1, characterized in that, The three-axis motion mechanism adopts the motion mechanism of a three-axis carving and washing machine, and the grinding execution mechanism adopts a wool grinding head.

3. A glass grinding machine based on PLC automated control according to claim 1, characterized in that, The communication unit includes an Ethernet interface and a Modbus communication protocol stack. The human-machine interface is physically connected to the PLC controller via Ethernet and realizes data interaction of control commands, process parameters, and operating status based on the Modbus protocol.

4. A glass grinding machine based on PLC automated control according to claim 1, characterized in that, The servo drive component includes a servo driver and a servo motor. The servo motor is equipped with an encoder, which is used to collect the actual position and speed information of the servo motor in real time and feed it back to the PLC controller. The PLC controller performs closed-loop regulation based on the PID algorithm, corrects the output pulse signal, and realizes the precise positioning and stable speed operation of the grinding actuator.

5. A glass grinding machine based on PLC automated control according to claim 1, characterized in that, The PLC controller includes a trajectory planning module, which includes a 5-point circle drawing algorithm unit. The 5-point circle drawing algorithm unit is used to automatically calculate and generate a continuous circular grinding trajectory based on the center coordinates and radius parameters input by the human-machine interface, and map the trajectory to the PLC coordinate system to drive the grinding actuator to grind cyclically along the circular trajectory.

6. A glass grinding machine based on PLC automated control according to claim 1, characterized in that, The human-computer interaction interface is used to input the XYZ three-axis coordinates of the defect location, the grinding speed ratio, and the grinding pressure parameters. It is used to display the servo motor running status, real-time values ​​of three-axis coordinates, grinding progress and system fault information; it is also used to store grinding process parameters corresponding to multiple sets of different defect specifications.

7. A glass grinding machine based on PLC automated control according to claim 1, characterized in that, The PLC controller also includes a parameter calibration module, which is used to lock the current speed ratio and pressure parameters as the optimal process parameters when the transition between the grinding area and the non-grinding area is smooth and no visible grinding marks are observed from multiple angles.

8. A control method for a glass grinding machine, used in the PLC-based automated control glass grinding machine as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Mark the location of scratches on the glass cover plate, control the three-axis motion mechanism through the human-machine interface to move the grinding actuator to the corresponding position of the defect, and record and save the XYZ three-axis coordinates. S2. Input the XYZ three-axis coordinates into the PLC controller and map them to the PLC coordinate system; S3. Input the grinding trajectory parameters and grinding process parameters to the PLC controller through the human-machine interface. The PLC controller generates a continuous grinding path according to the built-in trajectory algorithm. S4 and PLC controllers output high-speed pulse signals to the servo drive components, driving the grinding actuator to perform automated grinding according to the preset trajectory, speed and pressure. S5: The servo motor encoder provides real-time feedback of position and speed information, and the PLC controller performs closed-loop correction to ensure stable grinding trajectory and force. S6. After grinding is completed, the system is reset and waits for the next operation instruction.

9. The control method for a glass grinding machine according to claim 8, characterized in that, In S3, the grinding trajectory parameters include the center coordinates and radius. The PLC controller uses a 5-point circle drawing algorithm to generate a circular grinding trajectory. The grinding process parameters include grinding speed and grinding pressure. The parameters are obtained through experimental calibration. The judgment criteria are: the grinding area has no uneven depth, no visible scratches, and a natural transition with the surrounding glass.

10. The control method for a glass grinding machine according to claim 8, characterized in that, The human-machine interface is connected to the PLC controller via Ethernet and uses the Modbus communication protocol to complete command issuance, parameter writing, and status feedback. The closed-loop correction adopts a PID control algorithm. The PLC controller compares the deviation between the set position and the actual position and adjusts the number and frequency of output pulses in real time to eliminate positioning errors.

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