WO2021198877A1

WO2021198877A1 - Method and plant for the control and treatment of vehicle bodies

Info

Publication number: WO2021198877A1
Application number: PCT/IB2021/052577
Authority: WO
Inventors: Frank LEVERING; Daniel RASPONE
Original assignee: Geico Spa
Priority date: 2020-03-30
Filing date: 2021-03-29
Publication date: 2021-10-07

Abstract

A plant (10) for the treatment of vehicle bodies (12) comprises at least one vehicle body treatment station (13) and a system (11) for sequentially transporting bodies inside and outside the station. A control method comprises the steps of: acquiring images of the bodies during their transit in a verification area (17); comparing in an electronic processing unit (19) the images acquired and the sample images contained in an image database (20); emitting a non-compliance signal (21) if the comparison indicates differences exceeding predetermined thresholds.

Description

Title

"Method and plant for the control and treatment of vehicle bodies"

Description

The present invention relates to a method and a system for controlling plants for the treatment of vehicle bodies.

In treatment plants there are generally present various stations in which the objects to be treated are subjected to a specific treatment. For example, in the case of a plant for the treatment of vehicle bodies, there may be stations for the immersion treatment of the bodies in treatment liquids, stations for painting the bodies, verification stations, etc.

It is important that the object to be treated should arrive at the inlet of each station in a suitable condition both for entry into the station and for the treatment to be carried out inside it.

For example, it is important that the objects with movable parts should have these movable parts in the correct position, both in order to prevent impacts with parts of the station and in order to ensure that all the areas of the object are suitably treated.

In the case of motor vehicle bodies, the incorrect position of a bodywork or bodywork parts (such as the bonnet, boot, doors) could potentially damage the bodywork or station. For example, doors which are open too wide could hit against side parts of the station.

Furthermore, incorrect positioning could slow down the treatment process or result in it being ineffective or defective. For example, in the case of a process which involves exposing internal parts of the bodywork to the treatment or painting liquids, a movable part (such as a boot or a door) in an incorrect (even closed) position may prevent or hinder said exposure to the treatment liquids and the paints, in addition to damaging a robot arm which may be used to apply fluids or paints.

Also the existence of movable parts which by mistake have not been temporarily fixed in position could be a cause of problems. For example, treatment stations which involve the rotation or also only the inclination of the object could be damaged by the uncontrolled movement of the movable parts caused by said rotation or inclination. For example, in the case of treatment of bodies by means of immersion in liquid tanks, usually it is envisaged that the bodies are rotated or inclined to varying degrees in the liquid in order to allow the liquid to come into full contact with the surface of the body. If the side doors, bonnet or boot were to freely move during rotation of the body, the body and the station could be damaged or could also prevent only the correct contact between parts of the body and the liquid. Moreover, the sudden displacement of the weight of parts of the body may cause undesirable alterations or an increase in the tension on the structure, with consequent potential future problems or a reduction of the working cycle.

Even if movable parts are not present, any misalignment of the object along the transport system and inside the stations may result in damage. For example, bodywork which is not correctly aligned on the transport system risks colliding with the sides of the travel path or the stations (for example a tank containing the treatment liquid) or also the bodywork could become detached from its support skid, in particular during the inclination and/or overturning operations performed inside a treatment tank. This results not only in damage to the tank and to the bodywork, but also in a prolonged stoppage of production until the bodywork is removed from the tank.

The general object of the present invention is to provide a solution at least to the aforementioned problems, ensuring correct positioning of the objects and of any of its movable parts inside the treatment plants.

In view of this object the idea which has occurred is to provide, according to the invention, a method for controlling a plant intended for the treatment of vehicle bodies and comprising at least one vehicle body treatment station and a system for sequentially transporting bodies inside and outside at least one station, characterized by the steps of: acquiring images of the bodies during their transit in a verification area; comparing in an electronic processing unit the images acquired and the sample images contained in an image database; emitting a non-compliance signal if the comparison indicates differences exceeding predetermined thresholds.

Still according to the principles of the invention the idea which has occurred is to provide a plant for treatment of vehicle bodies, comprising at least one vehicle body treatment station and system for sequentially transporting bodies inside and outside at least one station, characterized in that it comprises in a verification area at least one camera intended to acquire images of the bodies during their transit in the verification area, an electronic processing unit connected to the camera and a sample image database connected to the processing unit, the processing unit being able to compare the images acquired by the camera and sample images contained in the image database so as to emit a non-compliance signal if the comparison indicates differences greater than predetermined thresholds.

In order to illustrate more clearly the innovative principles of the present invention and its advantages compared to the prior art, a possible example of embodiment applying these principles will be described below with the aid of the single attached drawing.

With reference to the Figure, this shows a plant applying the principles of the invention and denoted generally by 10.

The plant 10 comprises a sequential transport line or system 11 which transports motor vehicle bodies 12 between one or more treatment or processing stations of the type known per se. One of these stations is generally indicated by 13. For example, the stations 13 may be known stations for performing surface treatment by means of immersion inside tanks 14 containing a suitable liquid, or stations for carrying out painting, welding or other operations performed by known robotic arms, etc.

The transport system 11 may be for example a known conveyor system which crosses the plant with the bodies 12 which are moved in sequence at a suitable distance from each other. The transport system 12 may also be a known skid conveyor where the bodies are mounted on known skids 16.

An image analysis area 17 is present before one, some or all the processing stations 13. This area 17 may be simply an area where the body passes directed towards a processing station, or may be itself a specially equipped station, as will become clear below.

In this area 17 one or more cameras 18 are positioned so as to suitably record a body 12 in transit such that the images of at least those parts of the body which are to be monitored are acquired. The cameras 18 may be chosen so as to record moving images or also fixed images at predetermined intervals (for example whenever a body enters into the area 17).

The camera(s) 18 is/are connected to an electronic image processing unit 19 known per se (for example a suitably programmed computerized system) which receives the images and compares them with an image database 20 containing sample images of a correctly positioned body 16, namely a body which is correctly aligned on the transport system, and with its movable and/or fixed parts correctly positioned for entry and processing in the following processing station 13. The sample images may for example be obtained during a system set-up step, with recording of bodies 12 which have been manually checked as being correct. Comparison of the images may be performed using systems known per se: for example, the comparison may also be performed by means of a neural network or similar artificial intelligence system suitably provided and trained inside the processing unit 19.

The database may comprise reference measurements for the geometrical boundaries and may include images of correct/incorrect geometrical positions of the bodywork and its movable parts for graphical reference. The database may also record graphical reference data for a given period of time continuously or at given intervals captured by the camera.

The processing unit 19 compares the image of a body passing in the area 17 and compares it with the suitable images and/or information contained in the database 20 in order to check the correspondence thereof within possible predetermined non-compliance ranges. For example, a tolerance for the opening angle of the doors or other movable parts, as well a maximum acceptable tolerance for misalignment of the body on the conveyor, etc., may be provided and identified in the image taken by the camera 18 compared to the corresponding sample image contained in the database 20.

If the correspondence between a real image and a sample image exceeds the predefined tolerance, the processing unit 19 emits a corresponding non- compliance signal 21. The non-compliance signal may command an action to be carried out on the body so as to bring it back within the predetermined thresholds and/or may be an alarm signal.

This non-compliance signal 21 may for example be sent to one or more terminals 22 so that the situation may be viewed by a human operator at any moment and in real time. The terminal may for example receive both the recorded image which activated the non-compliance signal and the sample image which shows how the recorded object should have been correctly arranged. This allows effective human monitoring of the system from one or more selected positions. Moreover, the terminal 22 may also allow the reviewing of recorded events as well as the immediate indication and viewing of notifications/alerts/actions signalled by the system. The terminals 22 may also allow the operator to confirm that the anomalous situation has been corrected after an event indicated by a non-compliance signal 21 has been resolved.

The non-compliance signal 21 may also be sent to a correction station 23 in which the anomalous situation detected may be corrected, if possible. The correction station 23 may be downstream of the area 17 or also coincide with it. The correction station will in any case be arranged so as to receive the body 23 before it reaches a processing station 13 or a section of the plant for which the detected non-compliance would be damaging.

Human staff, who are alerted as to the detected non-compliance, may be for example present in the correction station 23. This alert may be provided for example by means of terminals 22 arranged in the zone 23, or some other known indication system, such as an optical and/or acoustic warning system.

Alternatively, or in addition, automatic systems, for example suitable known robotic arms 24 which correct the anomaly upon command by the unit 19, may also be present in the correction station 23.

For example, if the anomaly signalled is a movable part of the body which is incorrectly opened, closed or positioned at the wrong angle, the human operators or the automatic system 24 may displace the movable part so as to bring it back into the correct position before the body resumes its travel path towards the processing station 13.

If the correction station 23 coincides with an analysis area 17, the processing unit 19 may also perform a check that the correction operation has been successfully completed before the body continues further within the plant.

In the event of an uncorrectable non-compliance being detected in a correction station 23 (for example a body which has become excessively misaligned on the conveyor), the processing unit 19 may also command a deviation of the body from the normal path of the conveyor 11 and direct it along a path 25 towards a further treatment or reject zone 26.

During use of the system 10, the cameras may take photographs at intervals depending on the production or continuous videos for recording the relevant geometric values or the moving parts of each passing body.

The processing unit may compare the geometric values measured or visually observed with the preset acceptable values. If a value is detected as being beyond the limits of the database, the system sends a non- compliance signal in respect of the appropriate action to be undertaken owing to this non-compliance.

The appropriate action may consist of the removal of the body from the transport line or the manual and/or automatic elimination of the anomaly detected.

In the most critical cases (for example misalignment of the body on the conveyor such as to prevent any further movement of the body) the processing unit 19 may also command the stoppage of the plant until the impediment has been removed or repaired.

At this point it is clear how the objects of the invention have been achieved owing to a system which monitors the arrival of the bodies and allows suitable measures to be taken before a body may create problems for the transport system and/or for the processing stations of the plant. With the system described, which allows preliminary automatic observation of the risk and the possibility of preventive action, damage to the bodywork or to its movable parts owing to non-compliant positions is prevented. With the system according to the invention the need to interrupt production in order to remove, for example, a body which has become wedged inside or fallen into an immersion treatment tank, is also avoided, owing to preventive measures offered by the system and preventing a body at risk from entering into the treatment tank.

There is also a significant reduction in the risk of quality problems caused by an incorrect position of the body or its movable parts which could result in defective application of the treatment fluids.

Obviously, the system described may also have areas 17 which coincide with processing stations 13 such that the body may be monitored also during processing in the station, so as to detect automatically any changes which indicate for example undesirable freedom of movement for the bodywork or its parts. In the case where it is observed that the bodywork or a part thereof does not comply with the predefined acceptable operating parameters (for example a movable part moves in an incorrect manner during a bodywork immersion or overturning operation), the processing unit 19 may stop the station 13 in which the body is located and signal the problem so that it may be eliminated before the processing station suffers any damage.

Obviously the description given above of embodiments applying the innovative principles of the present invention is provided by way of example of these innovative principles and must therefore not be regarded as limiting the scope of the rights claimed herein. A practical embodiment of a plant according to the invention may obviously have variations compared to the embodiment described here by way of example. For example, the solution according to the present invention has been found to be particularly useful for use in a painting plant for assisting and reducing the need for observation by human personnel and monitoring of the problems and potential damage which could occur in this plants. However, the solution according to the invention is also suitable for other processing plants such as welding and/or assembly plants.

The limit thresholds for notifications, alerts and automated action may be established specifically in each case and in accordance for example with a specific use of the plant or specific requirements of the user. Based on the exact position of the camera on-site, the user's vision will be optimized to ensure suitable monitoring, also for example with the aid of suitable illumination systems.

Claims

1. Method for controlling a plant (10) intended for the treatment of vehicle bodies (12) and comprising at least one vehicle body treatment station (13) and a system (11 ) for sequentially transporting bodies inside and outside at least one station, characterized by the steps of: acquiring images of the bodies during their transit in a verification area (17); comparing in an electronic processing unit (19) the acquired images and sample images contained in an image database (20); emitting a non-compliance signal (21) if the comparison indicates differences greater than predetermined thresholds.

2. Method according to claim 1 , characterized in that the non-compliance signal (21 ) commands an action to be carried out on the body so as to bring the differences back within the predetermined thresholds.

3. Method according to claim 2, characterized in that the action carried out on the body so as to bring it back within the predetermined thresholds takes place in a correction station (23).

4. Method according to claim 3, characterized in that automatic correction devices (24) are present in the correction station.

5. Method according to claim 1 , characterized in that the non-compliance signal (21) is sent to signalling terminals for signalling the differences of a body to human personnel.

6. Method according to claim 1 , characterized in that the non-compliance signal (21) commands removal of a body from the transport system (11) and/or sending of the body to a repair or reject station (26).

7. Method according to claim 1 , characterized in that said at least one treatment station (13) is a station for immersion treatment of the body in a tank (14) containing treatment liquid and/or a station for performing painting by means of robotic arms (15).

8. Plant (10) for treatment of vehicles bodies (12), comprising at least one vehicle body treatment station (13) and a system (11) for sequentially transporting bodies inside and outside the at least one station, characterized by comprising at least one camera (18) in a verification area (17) intended to acquire images of the bodies during their transit in the verification area (17), an electronic processing unit (19) connected to the camera and a sample image database (22) connected to the processing unit (19), the processing unit being able to compare the images acquired by the camera (17) and sample images contained in the image database (20) so as to emit a non-compliance signal (21 ) if the comparison indicates differences that exceed predetermined thresholds.

9. Plant according to claim 8, characterized in that the non-compliance signal (21 ) is sent to a correction station (23) designed to produce an action on the body so as to bring it back within the predetermined thresholds.

10. Plant according to claim 9, characterized in that automatic correction devices (24), preferably in the form of robotic arms, are present in the correction station.

11 . Plant according to claim 8, characterized in that the non-compliance signal (21 ) is sent to signalling terminals (22) for signalling the differences of a body to human personnel.

12. Plant according to claim 8, characterized in that the non-compliance signal (21 ) commands removal of a body from the transport system (11 ) and/or sending of the body to a repair or reject station (26).

13. Plant according to claim 8, characterized in that said at least one treatment station (13) is a station for immersion treatment of the body in a tank (14) containing treatment liquid and/or a station for performing painting by means of robotic arms (15).