ES2843739B2 - ASSEMBLY PROCEDURE BASED ON A COLLABORATIVE ROBOTIC SYSTEM WITH INTERCHANGEABLE APPLICATIONS FOR AUTOMATED DRILLING, COUNTERSUNKING AND RIVETING OPERATIONS - Google Patents

Description

DESCRIPTION

ASSEMBLY PROCEDURE BASED ON A ROBOTIC SYSTEM

COLLABORATIVE WITH INTERCHANGEABLE APPLICATIONS FOR

AUTOMATED DRILLING, COUNTERSUNKING AND

RIVETED

OBJECT OF THE INVENTION

The present invention refers to a collaborative robotics-based system that supports the manufacturing and assembly of complex aeronautical structures.

It includes the analysis of the process and the development of assembly solutions that allow the integration of collaborative robots in production lines to carry out applications for drilling, countersinking, vacuuming and the installation of hi-lok and hi-lite rivets in carbon fiber and metallic structures.

Today the application of robots is very widespread in a wide variety of industrial sectors, especially in large-scale manufacturing plants, where they usually perform a large multitude of tasks such as welding, painting, assembly, 'pick-and-place ', product inspection and quality testing, all with great speed and relative precision. However, the latest advances in robotics technology and the miniaturization of electronic components and processors have ushered in a new era in industrial automation: that of collaborative robots.

Characterized by being light, flexible and easy to install, collaborative robots are specially designed to interact with humans in a shared workspace without the need to install security fences.

They offer a quick return on investment, they do not require specialized technicians for their assembly and start-up, they can be reconfigured to operate at various points in a production line and they allow companies to optimize their productivity. They represent a new era in industrial automation because they allow the introduction of robots in sectors and industrial processes in which, until now, it had not been viable.

Collaborative robots do not compete with traditional industrial robots, they are simply different. Collaborative robotics is a new form of industrial automation that complements the current offering.

As industrial companies increasingly adopt this technology, they benefit from the simplicity and flexibility that cobots offer them. Industries and companies where automation is less prevalent today due to the cost, risk, and low flexibility of traditional robots will benefit the most from collaborative robotics over the next decade.

Currently, the industrial processes of the Aeronautical Sector are still quite far from what Industry 4.0 represents in itself.

The aeronautical industry, due to the high competitiveness of the sector, faces an important need to reduce costs in its production processes.

Despite being a highly technological industry, most aeronautical assemblies are still poorly automated, due to the low production volumes compared to other industries, such as the automobile industry, which conditions the return on investment.

The current difficulties, such as the state of the art of robotic systems, do not allow their direct application in the aeronautical industry because their positioning and assembly precision does not meet the high requirements of this sector.

One of the pillars of the implementation of Industry 4.0 is Process Automation.

Within this automation of production processes there is always the decision between the degree of automation, where a point of conflict is the decision between the implementation of industrial robotics versus collaborative robotics.

In those processes where high-level robotization cannot be profitable due to the type of process, a solution to be developed is the implementation of collaborative robots.

Collaborative robots have to be designed to work safely and interact with operators, this means that they do not require cages and can work alongside the operator.

The present invention solves this problem, presenting technical advantages compared to other existing similar systems, providing a comprehensive solution for specific applications that allow automated operations to be carried out, mainly:

- Automated riveting operations for collaborative robots, by means of an electric head coupled to robot c, which allows to carry out rivet feeding tasks from an automated feeding system, rivet positioning, riveting and digital verification of the operation. This device has a built-in torque sensor to ensure the torque or breakage of the collar, allowing the riveting operation to be consolidated.

- Drilling, countersinking and aspiration operations with very high precision requirements, through the use of templates and calibration systems, as well as specific software integrated into the system that allow the minimization of any errors.

- Communication operations, monitoring / management and man & Robot interface, based on the programming of the following hardware: collaborative robot, operator, peripherals and communication system through HMI for the execution of mechanical operations of drilling, countersinking, aspiration and riveting, starting of an automated equipment management system and communications between the different devices, which allows managing the safety of the operators by means of safety sensors, a system of calibration and configuration of tolerances and precisions by means of artificial vision equipment and interconnection between the hardware elements for the configuration of the manufacturing process.

In summary, this invention includes the development of a new equipment that, through measurement and positioning systems, allows to automate complex operations in the aeronautical sector from portable devices that will manage the operators. This seeks to increase the productivity and flexibility of the production lines, in addition to improving the quality, safety and ergonomics of the operators.

The advantages of this invention are as follows:

- Flexible adjustment to the needs of synchronization of manufacturing processes and integrated logistics.

- Monitoring of the situation and degree of progress in real time.

- Real simulation and continuous improvement of processes.

- Decrease in production times.

- Fully integrated industrial security.

- Assurance of the quality levels required in the aeronautical sector.

For all this, sensors and peripherals are integrated that guarantee the efficiency and robustness of routine assembly operations, preserving the safety and ergonomics of the operator, within the framework of Innovation and Development. Parametric tables and algorithms are established for their location in an optimized way based on the work areas corresponding to each structural element.

The industrial application of this invention is within the implementation and development of precision operations systems that guarantee compliance with the requirements of the aeronautical industry.

BACKGROUND OF THE INVENTION

In the technological and productive context in which we find ourselves, the following needs arise related to robots in the implementation in different sectors:

• They must be even more precise. The current technology of robots produces errors in the positioning of parts, and cannot be used within sectors where very tight tolerances are required.

• They have to be safer and work in collaboration with the operators.

• They must be multifunctional. Collaborative robots must carry out several processes on the same structure to ensure their profitability.

• The lack in the current market of tool heads adapted to robots for production processes.

• They must be adapted to new safe collaborative work spaces, where they will work with people.

They have to recognize their environment, using sensors and cameras, and act according to the circumstances and endow them with a certain intelligence.

Although no invention identical to that described has been found, we present below the documents found that reflect the state of the art related thereto.

Thus, document ES2666834T3 refers to an improved automatic riveting system, of the type used in precision robotic installations for the performance of multiple functions with the same equipment, which consists of a parallel kinematics machine that comprises a set of several single-function heads individually fixed and aligned in parallel to a working flange of the parallel kinematics machine, the latter being in charge of making the appropriate movements of the independent single-function heads to the same working point during the different phases of riveting, these movements of the machine being of parallel kinematics equivalent to the correction of its numerical control to compensate the displacement or offset between the independent monofunction heads. Said improved system only refers to riveting, while the main invention contemplates other operations, such as drilling.

CH101005908A proposes an improved automatic riveting system for an automatic precision device that implements multiple functions in the same device, that the automatic riveting system employs a single-function independent tool head that is fixedly coupled to a machine tool parallel to through a mechanical connection flange. It coincides with its national counterpart, explained above.

CN102083567A describes a multifunction device for automatic riveting by digital control, which is suitable for riveting engagement of metal parts, carbon fiber parts, fiberglass parts or other parts having strict manufacturing tolerances, as in the aerospace industry. The device comprises a machine or robot with a high precision positioning system that moves by digital control and is provided with a head that is applied to the pending piece; wherein the head has a plurality of single function modules, each of the single function modules performs continuous operation at a single point of operation. Positioning system comprises digitally controlled Cartesian machine, gantry, bridge gate, "C" type machine or other machine, parallel kinematic machine or robot, precision articulated robot, or has machines or robots with sufficient precision and repeatability to apply to large structures with tight tolerances. As in the documents cited above, it is a device / system that does not comprise instrumentation dedicated to other activities such as drilling, for example, which are contemplated in the system that is the object of the main invention.

CN105642769A proposes a riveting mechanism with the function of automatically changing the riveting heads. The riveting mechanism comprises a bracket, a first actuator attached to the bracket, a pressure block driven by the first actuator to move up and down, and an automatic switch module attached to the bracket and located below the block. pressure, wherein the switch module comprises an electric servo cylinder attached to the bracket, a plurality of independent guide sleeves, connecting rods, and riveting heads; The guide sleeves are fixed to the movable end of the electric servo cylinder and are driven by the electric servo cylinder to move left and right, the connecting rods are housed in the guide sleeves, and the riveting heads are fixed to the lower parts of connecting rods. Once again, it is a mechanism aimed exclusively at riveting, with automatic head change, and which does not include other functions as does the main invention.

Conclusions: As can be seen from the research carried out, none of the documents found solves the problems posed as the proposed invention does.

DESCRIPTION OF THE INVENTION

The collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations that is the object of the present invention is constituted from a station that comprises the following elements:

Collaborative anthropomorphic six-axis robot with external contact sensors, which guarantee the safety of the operators.

Robot controller characterized by high performance processors and servo amplifiers that manage all the robot axes.

Translation system that allows the collaborative robot to move, thus increasing its reach.

Automatic rivet feeding and positioning system mainly composed of an electromagnetic vibrator system that allows continuous feeding of rivets to the riveting system.

Tool holders. Tool storage system to carry out drilling, countersinking and riveting operations. This system may be equipped with sensors to have greater control of the system.

Applications. Tools of the different assembly processes that are stored in the tool holder. These applications or end-effector, will be arranged to carry out the different operations of drilling, countersinking, positioning the bolt and riveting, thus carrying out the complete assembly process required in structures that require these operations.

TCP (Tooling Control Point) calibration system that calibrates assembly applications electronically. The robot program is corrected automatically by measured variations and ensures that the tool always works in the correct position.

Safety sensors that serve to protect dangerous areas, protection of dangerous points or protection of access to machines and systems. These sensors allow the recognition of the environment, being able to vary the parameters of the system always oriented to the safety of the operators. These can be photoelectric cells, radars, laser scanners, etc.

Electrical cabinet composed of PLC, thermal magnetos and necessary safety modules that allow the power supply, distribution, management and conversion of electrical energy.

Tools. Necessary support structure that allows the positioning of the part to be assembled. This tool has a template with holes to carry out drilling and countersinking operations.

Artificial vision system for verification of the processes carried out by means of contour recognition. It will carry out the drilling, countersinking, bolt positioning and riveting checks.

HMI (Human-Machine Interface) interface that serves as an intermediary between the operations and the robot, which controls the main parameters of the collaborative system.

And in turn, the collaborative robot comprises a head with an automatic exchanger (part A) with the following applications, and elements:

Electric multifunctional head that allows the control of advance, control of revolutions and control of the tightening torque. This head has a controller to facilitate its communications and therefore its versatility. Integrated to the head is an automatic change system (Part A) that allows the application change, thus being able to carry out different operations with the same head.

Multi-component stress sensor that allows the robot to detect the force and torque applied to the end-effector in 6 degrees of freedom.

Two-way solenoid valve that provides pneumatic supply to the Concentric Collet in drilling and countersinking applications.

Drilling and countersinking application by Concentric Collet (part B of the integrated exchanger). Composed by:

Part B, Element that serves as an interface between the drilling or countersinking application and the spindle.

Concentric Collet. The drilling and countersinking operation is carried out by means of an expander bushing that fits into a metal template provided in the tooling for this purpose. This expander bushing is activated and deactivated pneumatically.

Cutting tool clamping system, necessary for drilling and countersinking applications.

Riveting application for hi-lok and hi-lite rivets (part B of the integrated exchanger).

Part B, Element that serves as an interface between the riveting application and the head.

Riveting tool according to the riveting requirements for Hi-lok and Hi-Lite rivets.

All the elements described above are aimed at the manufacture of large complex aeronautical structures, specifically the drilling, countersinking and riveting tasks, which are developed in the following technical stages:

- Reconocimiento de entorno colaborativo para auto parametrización de valores en estación colaborativa.I.

- Recognition of collaborative environment for self-parameterization of values in collaborative station.

- Calibración en cabezal de la interfaz de unión con la aplicación, por medio de sistema de auto calibración TCP (Tooling Control Point).II.

- Calibration in head of the interface of union with the application, by means of the self-calibration system TCP (Tooling Control Point).

III.- Robot return to Zero Position to start the assembly activity governed by the HMI.

Once these general tasks for the station have been carried out, the specific tasks of the two fields of action of the system object of the present invention are detailed, be it drilling / countersinking or riveting:

Drilling or countersinking process

IV ’.- Activate the mounting application tool for drilling or countersinking.

V ’.- Calibrate the Drilling or Countersinking Tool via TCP.

VI ’.- Select drilling or countersinking sequence in HMI.

VII ’.- Activation of automated operation for approach of the application of assembly to jig tooling for embouching of Concentric Collet.

VIII '.- Auto parameterization in approach to template by means of the stress sensor, to insert the Expansion Bushing in template.

IX '.- Expansion of the concentric collet cap by pneumatic activation.

X ’.- Carrying out the drilling or countersinking operation, depending on the feed and cut parameters previously selected in HMI.

XI ’.- Output of the assembly application template for completion of the process.

XII '.- Verification of the operation and status by means of an artificial vision system.

XIII '.- Completion of the complete sequential cycle selected.

XIV ’.- Return robot to Zero Position to start new assembly activity.

Riveting process

IV ’’ .- Activate assembly application tool for riveting application.

V ’’ .- Calibrate the Riveting Tool via TCP

VI '' .- Recognition of the state of the piece to be riveted by means of an artificial vision system.

VII ’’ .- Select drilling or countersink sequence in HMI.

VIM ’’ .- Automatic rivet feeding.

IX ’’ .- Approach and performance of the riveting process.

X ’’ .- Verification of the operation by means of artificial vision.

XI ’’ .- Carrying out the complete sequential cycle selected.

XII ’’ .- Return robot to Zero Position to start new assembly activity.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present description, some drawings are attached that represent a preferred embodiment of the present invention:

Figure 1: General plan view and detail of the automated robotic system for drilling, countersinking and riveting of interchangeable heads object of the present invention.

Figure 2: Detail of the electric multifunctional head of the automated robotic system for drilling, countersinking and riveting of interchangeable heads object of the present invention.

Figure 3: Elevation view of the six-axis anthropomorphic collaborative robot mounted on a linear track translation system.

Figure 4: Elevation view of the six-axis anthropomorphic collaborative Robot mounted on a mobile platform.

Figure 5: Exploded view in detail of the application head for drilling.

Figure 6: Exploded view in detail of the application head for riveting.

Figure 7: Drilling or Countersinking Flow Chart

Figure 8: Riveting flow chart.

The numerical references that appear in said figures correspond to the following constitutive elements of the invention:

1. Collaborative robot

2. Translation system

3. Automatic rivet feeder system

4. Tool holder

5. TCP calibration system

6. Security sensor system for collaborative environments

7. Controller

8. HMI interface

9. Electrical panel

10. Head

11. Automatic heat exchanger

12. Mounting application:

12 ’application for drilling or countersinking

12 ’’ application for riveting

13. Solenoid valve

14. Multi-component stress sensor

15. Artificial vision system

16. Monitor for process control

17. Tooling

DESCRIPTION OF A PREFERRED EMBODIMENT

A preferred embodiment of the automated robotic system for drilling, vacuuming and riveting with a head and different interchangeable applications object of the present invention, with reference to the numerical references, can be based on a work station for drilling and riveting by means of a collaborative robot (1 ) of 15 kg and six axles mounted on a translation system (2) based on a 3-meter linear track to move along the station and access the different points and tools (17) described below, which also It also has an automatic rivet feeder system (3), a tool holder (4), TCP calibration system (5), a safety sensors applied to collaborative environments (6), robot controller (7), HMI interface (8) and electrical panel (9) with their electrical and electronic signal management elements.

In addition, the collaborative robot (1) comprises a head (10) with programmable electronics and an automatic exchanger (11) to couple different assembly applications (12), depending on the work operation to be carried out, either using an application for drilling or countersinking (12 ') by concentric collet, or an application for riveting (12' ') hi-lok or hi-lite, as well as other complementary elements such as a solenoid valve (13), a multi-component stress sensor (14 ), and an artificial vision system (15).

This configuration of the head (10) coupled to the robot allows us to carry out multiple assembly processes. The head has electronics with advance control, speed control and torque control.

The concentric collet is composed of an expander bushing coupled to the mounting application for drilling and countersinking operations (12 "). The concentric collet head is a pneumatically equipped adapter and mechanical feed. A first action of the system allows to retract the chuck from the tip of the concentric collet. A second action of the system allows the expandable mandrel to lock into the drill sleeve. A forward movement of the nose by the mechanism also allows contacting and pushing the workpiece.

The support of a multi-component force sensor (14) coupled to the collaborative robot (1) allows to control the forces in the drilling and countersinking processes. This effort control allows absorbing small deviations that would have occurred greater than one tenth, recalibrating the robot in its final adjustment movement for the correct drilling and countersinking operation.

The artificial vision system (15) is capable of identifying any physical element, so it is useful to check that there is a bolt inserted in the hole or to check that the nut is already installed.

The user / operator also has a monitor for process control (16), which records and stores the system parameters in real time, and an interface HMI (8) of communication between collaborative man & robot that controls the main parameters of the collaborative system. This interface allows the operator to govern the actions carried out by the robot when the process requires it.

For this example, the tool holder (4) has four applications, which are, an application for drilling, an application for countersinking and two applications for riveting, of which one is for riveting with easy access (straight head) and the other for riveting with difficult access (angled head), the number of which can be expanded for greater flexibility in assembly operations.

The collaborative environment is mainly made up of safety sensors (6) that delimit different work areas. An intelligent system programmed, manages the parameters of the station according to the people it detects in different areas. These areas are:

Collaborative Zone. Area that activates all collaborative security systems according to current regulations.

Intermediate Zone. Area in which the parameters are optimized according to the law on the prevention of occupational hazards applied in collaborative robots.

Industrial zone. Zone in which the industrial parameters of the robot are activated, disabling the collaborative sensor.

Claims (1)

1.- Assembly procedure by means of a collaborative robotic system with interchangeable applications for automated operations of drilling, countersinking, aspiration and riveting, characterized by being developed in the following technical stages, the first three being common for any type of operation, and dividing from the fourth depending on whether they are drilling / countersinking or riveting tasks: I.

- Recognition of collaborative environment for self-parameterization of values in collaborative station. II.

- Calibration in head of the interface of union with the application, by means of the self-calibration system TCP (Tooling Control Point). III.

Robot return to Zero Position to start the assembly activity governed by the HMI. Specific to the drilling or countersinking process: IV ’.- Activate the mounting application tool for drilling or countersinking. V ’.- Calibrate the Drilling or Countersinking Tool via TCP. VI ’.- Select drilling or countersink sequence in HMI. VII ’.- Activation of automated operation to approach the assembly application to the jig tooling for the Concentric Collet outlet. VIII '.- Auto parameterization in approach to the template by means of the stress sensor, to insert the Expansion Bushing in the template. IX '.- Expansion of the concentric collet cap by pneumatic activation. X ’.- Carrying out the drilling or countersinking operation, depending on the feed and cut parameters previously selected in HMI. XI '.- Output of the assembly application template for completion of the process. XII '.- Verification of the operation and status by means of an artificial vision system. XIII '.- Completion of the complete sequential cycle selected. XIV ’.- Return robot to Zero Position to start new assembly activity. And specific to the Riveting Process: IV ’’ .- Activate assembly application tool for riveting application. V ’’ .- Calibrate the Riveting Tool via TCP VI ’’ .- Recognition of the state of the piece to be riveted by means of an artificial vision system. VII ’’ .- Select drilling or countersink sequence in HMI. VIII ’’ .- Automatic rivet feeding. IX ’’ .- Approach and performance of the riveting process. X ’’ .- Verification of the operation by means of artificial vision. XI ’’ .- Carrying out the complete sequential cycle selected. XII ’’ .- Return robot to Zero Position to start new assembly activity. 2.- Collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations, used in the development of the technical steps described in claim 1, characterized by comprising a collaborative robot (1) mounted on a translation system (2 ), an automatic rivet feeder system (3), a tool holder (4), a TCP calibration system (5), a system of applied safety sensors for collaborative environments (6), robot controller (7), HMI interface (8), a monitor for process control (16) and electrical panel (9) with its electrical and electronic signal management elements, where said collaborative robot (1) comprises a head (10) with programmable electronics and a automatic heat exchanger (11) to fit an application for drilling or countersinking (12 ') by concentric collet, or an application for riveting (12 '') hi-lok or hi-lite, as well as other complementary elements such as a solenoid valve (13), a multi-component stress sensor (14), and an artificial vision system (15). 3.

- Collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations, according to claim 2, where the tool holder (4) and the head (10) with programmable electronics and an automatic exchanger (11) support four applications (12) which are, one application for drilling, one application for countersinking and two applications for riveting, of which one is for riveting with easy access (straight head) and the other for riveting with difficult access (angled head ). 4. - Collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations, according to claim 2, where the collaborative robot (1) can be fixed in the station, and not mounted on a translation system. 5. - Collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations, according to claims 2 to 4, where a support structure or tooling (17) which allows the positioning of the piece to be assembled has a template with holes for drilling and countersinking operations. 6. - Collaborative robotic system with interchangeable applications for automated drilling, countersinking and riveting operations, according to claims 2 and 3, where the automatic exchanger (11) of the head (10) comprises two parts, one fixed, integrated in it and the other variable according to the type of application (12) to be coupled, which can be independent of the application or be integrated into the application itself (12).