CN117655719A - Intelligent control and visual positioning error compensation system of full-automatic riveter - Google Patents

Abstract

The invention belongs to the field of intelligent control systems, and particularly relates to an intelligent control and visual positioning error compensation system of a full-automatic riveting machine. The device comprises a production and manufacturing execution system, a logic control unit, an industrial bus switch, a drawing identification unit, a three-degree-of-freedom gripper, a visual positioning error compensation unit and a motion control unit. According to the invention, the visual positioning error compensation system is used for calibrating the hole site in real time, the real-time feedback is carried out on the hole site to the motion control system for dynamic error compensation, and meanwhile, the intelligent control system of the full-automatic riveting machine is assembled by applying the intelligent scheduling and path planning algorithm, so that full-automatic riveting of different types of lining plates and studs can be realized.

Description

An intelligent control and visual positioning error compensation system for fully automatic riveting machines

Technical field

The invention belongs to the field of intelligent control systems, specifically an intelligent control and visual positioning error compensation system for a fully automatic riveting machine.

Background technique

At present, in the elevator industry, the process requires riveting of different types of lining plates and studs. Since there are many types of lining plate products, the sizes of the products vary greatly. At the same time, due to the errors of the servo transmission mechanism itself and the different types of plates, The cumulative error generated during laser punching in the previous process causes a large error between the theoretical position and the actual position of each riveting hole. Therefore, the current riveting of lining plates and studs uses the semi-automatic operation of a manual pressure riveting machine. The riveting holes are manually aligned, and then the riveting machine performs the riveting work. At the same time, the traditional control method cannot achieve real-time deviation parameters. Dynamic adjustment cannot achieve automatic calibration of riveting hole positions. When the type of lining plate changes, the adjustment process requires a lot of manpower and material resources, resulting in assembly efficiency and quality not being guaranteed, and labor cost consumption being serious.

Contents of the invention

Based on the above shortcomings, the present invention is an intelligent control and visual positioning error compensation system for a fully automatic riveting machine. The hole position is calibrated in real time through the visual positioning error compensation system and fed back to the motion control system in real time for dynamic error compensation. At the same time, intelligent The production scheduling and path planning algorithm combined with the intelligent control system of the fully automatic riveting machine can realize fully automatic riveting of lining plates and studs.

The technical solutions adopted by the present invention to achieve the above objects are:

An intelligent control and visual positioning error compensation system for a fully automatic riveting machine, including:

The manufacturing execution system is used to store production and manufacturing data, and generate motion control instructions based on the motion control data and send them to the logic control unit;

The logic control unit is used to obtain motion control data based on drawing data and error data, send it to the manufacturing execution system and receive motion control instructions;

Industrial bus switch, used for the logic control unit to interact with the drawing recognition unit, three-degree-of-freedom gripper unit, visual positioning error compensation unit and motion control unit respectively;

The drawing identification unit is used to obtain the drawing data corresponding to the plate by identifying the QR code on the plate;

The three-degree-of-freedom gripper unit is used to control the three-axis gripper to grab the plate to a set position based on motion control instructions when the plate model changes;

The visual positioning error compensation unit is used to obtain the position of the plate in real time through the camera and perform mapping between the camera coordinate system and the machine tool coordinate system through the system calibration method, calculate the error between the actual position of the plate and the reference position, and send the error data to the logic control unit;

Motion control unit is used to control the servo drive according to motion control instructions.

The manufacturing execution system includes an MES system and a product database used to store manufacturing data.

The production data includes production schedules and start and finish times.

The logic control unit is a PLC control system.

The drawing identification unit includes automatic drawing identification software, a drawing database and a code scanning mechanism. The scanning mechanism identifies the QR code on the plate and sends the QR code data to the automatic drawing identification software. The automatic drawing identification software Match the corresponding drawing data in the drawing database.

The visual positioning error compensation unit identifies the deviation value between the actual position of the hole on the plate and the reference position through edge fitting and distortion correction.

An intelligent control and visual positioning error compensation method for a fully automatic riveting machine, including the following steps:

After the plates are placed, the drawing recognition unit identifies the QR code on the plates, queries the drawing database to determine the model of such plates, and then determines the number and location of riveted holes for such plates, and excludes holes that cannot be riveted when riveting such plates. Bit;

The logic control unit allocates riveting tasks based on the minimum beat principle to determine the number and location of riveting holes required for each fully automatic riveting machine station;

The logic control unit plans the sequence of riveting each hole through the optimal path algorithm;

After obtaining the position and sequence of the holes that need to be riveted, the motion control unit controls the three-degree-of-freedom gripper unit to grab the plate and move it to the reference position of the holes in sequence;

The visual positioning error compensation unit identifies and calculates the deviation value between the actual position of the hole and the reference position through visual positioning, and feeds back the deviation XY value to the logic control unit;

The logic control unit controls the three-degree-of-freedom gripper unit to move the plate for error compensation and prepare for riveting.

The holes that cannot be riveted when riveting the plate include:

Due to the mechanical obstruction of the three-degree-of-freedom gripper itself, the riveting machine does not have holes for the riveting space and the holes for setting the space around each lining display according to the process requirements.

The invention has the following beneficial effects and advantages:

1. Full process automation of the system: The invented intelligent control system of the fully automatic riveting machine can realize fully automatic pressure riveting between different types of plates and studs. It can identify the size of the current plate and the holes that need to be riveted through the drawing recognition module. Position and quantity, the intelligent scheduling module can be used to dynamically adjust the riveting sequence in real time, and perform fully automatic intelligent riveting between the lining plate and the stud.

2. The system has advanced algorithms and high reliability: The invented visual positioning error compensation system realizes mapping of multiple coordinate systems through calibration, and uses advanced algorithms such as edge fitting and distortion correction to quickly identify the theoretical position and actual position of each riveting hole. The XY value of the position deviation is fed back to the intelligent control system in real time for rapid dynamic adjustment, the hole position is aligned, and automatic riveting is performed, which improves the efficiency and quality of assembly.

3. The system has good versatility and strong scalability: the control system of the present invention adopts a modular design, has an open architecture, and is flexible in configuration. It can be applied to different industrial bus vision and motion control systems, and the control program and visual positioning error compensation program can be expanded. , portable, and applicable to various hardware structures.

Description of drawings

Figure 1 is an architecture diagram of an intelligent control and visual positioning error compensation system for a fully automatic riveting machine.

Figure 2 is a fully automatic riveting structure diagram of an intelligent control and visual positioning error compensation system for a fully automatic riveting machine.

Figure 3 is a control system flow chart for the specific implementation of the intelligent control and visual positioning error compensation system of a fully automatic riveting machine.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and examples.

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are clearly and completely described below in conjunction with the drawings of the present invention.

The present invention is an intelligent control and visual positioning error compensation system for a fully automatic riveting machine. Refer to Figure 1. It includes a manufacturing execution system 101, a logic control unit 102, an industrial bus switch 103, a drawing recognition unit 104, and three freedom systems. Degree gripper 105, visual positioning error compensation unit 106, motion control unit 107.

As mentioned above, the manufacturing execution system includes the 101MES system, product database, production schedule, start and finish time, etc. The advantage is that the logic control unit 102 can send and receive MES system data through the server in real time.

As mentioned above, the logic control unit 102 includes a PLC CPU control system and control logic for each unit of the entire system. It has the advantages of supporting Profinet bus control, motion control module, adaptive adjustment of motor parameters, rhythm control, fault alarm and other functions.

As mentioned above, the industrial bus switch 103 includes switches that support multiple industrial buses and is responsible for the data exchange function of the entire system.

As mentioned above, the drawing recognition unit 104 includes a set of existing drawing automatic recognition software (supporting Profinet bus communication protocol), a drawing database, and a code scanning mechanism. It can determine the model of the current plate based on the QR code data fed back by the code scanning mechanism in real time. The number and theoretical location of riveting holes required for the plate can be determined by the model.

As mentioned above, the three-degree-of-freedom clamp 105 includes a pneumatic gripper mechanism loaded with three transmission shafts, each equipped with three absolute encoder servo motors (supporting Profinet bus communication protocol). When the plate model changes, the motion control command can Real-time control of the position of the three-axis gripper to grab the plate can ensure that each hole can be moved to the visual lens for photo calibration.

As mentioned above, the visual positioning error compensation unit 106 includes an industrial smart camera, a lens, a vision controller (supporting the Profinet bus communication protocol), and a light source. It realizes mapping of multiple coordinate systems through system calibration and uses advanced algorithms such as edge fitting and distortion correction. It can quickly identify the deviation value between the actual position of the hole and the reference position, guide the motion control system to move quickly, and meet the requirements of accurate automatic riveting. It can provide real-time feedback on the XY axis deviation between the actual position of each hole and the theoretical position. Distortion correction, feature recognition and other algorithms are used in the visual positioning error compensation process, and the visual accuracy can reach ±0.01mm.

As mentioned above, the motion control unit 107 includes a servo driver that supports the industrial bus (supports the Profinet bus communication protocol). Each driver controls the corresponding motor to perform position control, speed control and other control modes. The encoder can feedback the current speed and position in real time. In the logic Write the motion control module in the control unit for programming control.

The complete fully automatic riveting production line involved in the present invention has three identical fully automatic riveting machine stations to complete the riveting of all holes on each lining plate. The distribution of the riveting holes required for each station can achieve balanced production capacity and consistent rhythm. Efficient and flexible production scheduling balances production resources and improves production delivery capabilities.

See Figure 2,

The mechanical structure of the fully automatic riveting station according to the present invention consists of a gripper 201, a machine vision 202, a three-degree-of-freedom slide 203, a transfer platform 204, and a riveting machine 205.

See Figure 3 for specific implementation steps.

Step 1: When the system is ready, the lining board is put online. After the plate is scanned by the automatic code scanning mechanism in the previous process, the PLC controls the manipulator to transport it to the transfer platform 204 based on the QR code information, and the plates are placed according to different plate models. The positions are different, and there are secondary positioning mechanisms in the length and width directions. After placing the plates, the manipulator notifies the logic control unit that the lining material is completed, and at the same time, the PLC sends the QR code information to the drawing recognition unit.

Step 2: After receiving the QR code information of this plate, the drawing recognition unit queries the database to determine the model of this type of plate, and then determines the number and location of riveting holes for this type of plate, and at the same time excludes the hole positions that cannot be riveted when riveting such plates: 1. Since the mechanism of the gripper 201 itself is blocked, the holes without riveting space of the riveting machine will not be riveted, and the riveting will continue at the next station. 2. Calculate the holes in the specific space around each liner display according to the process requirements without riveting. The number and location of the remaining holes need to be riveted.

Step 3: The logic control unit allocates tasks based on the minimum beat principle to achieve balanced production capacity, consistent beats, efficient and flexible production scheduling, balanced production resources, and then determines the absolute coordinates corresponding to the movement of each hole of the three-degree-of-freedom slide table 204 under the visual lens. The XY values and coordinate values are sent to the PLC logic control unit 102 through Profinet.

The minimum beat principle is specifically:

(1) Enter the hole coordinate set;

(2) Determine whether the round hole interferes. If it interferes, proceed to step (3); if it does not interfere, proceed to step (4);

(3) Determine the interference station number of the interference round hole. If all stations are interference stations, then the round hole will not be able to be automatically riveted; if there is a non-interference station for the round hole, add the round hole Go to the nearest work station set;

(4) Determine whether the work station of the round hole set reaches the maximum capacity N. If not, add the round hole to the work station set. If the capacity is reached, proceed to (5);

(5) Add the round hole to the station set closest to the original station and execute (4) again;

Step 4, the path planning system, after confirming the number and location of the holes that need to be riveted at each fully automatic riveting machine station, will use the optimal path algorithm to plan the order of riveting each hole according to the beat requirements, and pass this data through Profinet is sent to the PLC logic control unit 102.

The optimal path algorithm is specifically:

(1) Determine the number M of riveting round holes in a single station, and the distance between two round holes is represented by L _CiCi+1 . Then the loss function of a single station can be expressed as:

In the formula, v represents the moving speed, and t represents the riveting time.

(2) Calculate the loss function of each workstation. The final loss function is expressed as:

L=MAX(L _i )

(3) Traverse N, recalculate the minimum beat principle, and take the calculation result when the loss function is the smallest as the final riveting path.

Step 5, the motion control system, after obtaining the position and sequence of the holes that need to be riveted, the three-degree-of-freedom slide 203 moves to the theoretical position of the holes in sequence, so that the vision camera can take pictures of the holes that currently need to be riveted, and the visual positioning error After the compensation system gives the XY value of the deviation between the actual value and the theoretical value, it can move and calibrate in real time to prepare for the next step of automatic riveting work.

Step 6: Visual positioning error compensation system. After the three-degree-of-freedom sliding table moves to the theoretical position of each hole, it triggers visual photography. The visual positioning travel compensation system uses advanced algorithms such as edge fitting and distortion correction to quickly identify the actual position of the hole. The deviation value between the position and the reference position can quickly feedback the deviation XY value, guiding the three-degree-of-freedom slide table to move the hole and pin, and prepare for the next step of automatic riveting.

Step 7: After the three-degree-of-freedom gripper completes the hole-piercing work, the control system controls the riveting head of the riveting machine to blow the nails, lower the riveting, complete the riveting, and enter the next automatic riveting cycle until required by this station. The riveted holes are all riveted.

Claims (8)

1. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine, which is characterized by: The manufacturing execution system is used to store production and manufacturing data, and generate motion control instructions based on the motion control data and send them to the logic control unit; The logic control unit is used to obtain motion control data based on drawing data and error data, send it to the manufacturing execution system and receive motion control instructions; Industrial bus switch, used for the logic control unit to interact with the drawing recognition unit, three-degree-of-freedom gripper unit, visual positioning error compensation unit and motion control unit respectively; The drawing identification unit is used to obtain the drawing data corresponding to the plate by identifying the QR code on the plate; The three-degree-of-freedom gripper unit is used to control the three-axis gripper to grab the plate to a set position based on motion control instructions when the plate model changes; The visual positioning error compensation unit is used to obtain the position of the plate in real time through the camera and perform mapping between the camera coordinate system and the machine tool coordinate system through the system calibration method, calculate the error between the actual position of the plate and the reference position, and send the error data to the logic control unit; Motion control unit is used to control the servo drive according to motion control instructions. 2. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine according to claim 1, characterized in that the manufacturing execution system includes an MES system and a product database for storing production and manufacturing data. 3. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine according to claim 2, characterized in that the production and manufacturing data include production schedules and start and finish times. 4. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine according to claim 1, characterized in that the logic control unit is a PLC control system. 5. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine according to claim 1, characterized in that the drawing recognition unit includes automatic drawing recognition software, a drawing database and a code scanning mechanism, and the scanning unit The coding mechanism recognizes the QR code on the plate and sends the QR code data to the automatic drawing recognition software. The automatic drawing recognition software matches the corresponding drawing data in the drawing database. 6. An intelligent control and visual positioning error compensation system for a fully automatic riveting machine according to claim 1, characterized in that the visual positioning error compensation unit identifies the holes in the plate through edge fitting and distortion correction methods. Deviation value between actual position and reference position. 7. An intelligent control and visual positioning error compensation method for a fully automatic riveting machine, which is characterized by including the following steps: After the plates are placed, the drawing recognition unit identifies the QR code on the plates, queries the drawing database to determine the model of such plates, and then determines the number and location of riveted holes for such plates, and excludes holes that cannot be riveted when riveting such plates. Bit; The logic control unit allocates riveting tasks based on the minimum beat principle to determine the number and location of riveting holes required for each fully automatic riveting machine station; The logic control unit plans the sequence of riveting each hole through the optimal path algorithm; After obtaining the position and sequence of the holes that need to be riveted, the motion control unit controls the three-degree-of-freedom gripper unit to grab the plate and move it to the reference position of the holes in sequence; The visual positioning error compensation unit identifies and calculates the deviation value between the actual position of the hole and the reference position through visual positioning, and feeds back the deviation XY value to the logic control unit; The logic control unit controls the three-degree-of-freedom gripper unit to move the plate for error compensation and prepare for riveting. 8. A method of intelligent control and visual positioning error compensation for a fully automatic riveting machine according to claim 7, characterized in that the holes that cannot be riveted when riveting the plate include: Due to the mechanical obstruction of the three-degree-of-freedom gripper itself, the riveting machine does not have holes for riveting space and holes for setting the space around each lining display according to process requirements.