DE102022127300A1 - Tool, system and method for automated positioning of an inflation tool on a tire valve of a rim - Google Patents

Abstract

The invention relates to a system and a tool for the automated positioning of an inflation tool on a tire valve of a rim, comprising an inflation tool and a camera, wherein the tool has a defined spatial relationship between the optical axis of a lens of the camera and an axis of action of the inflation tool. The invention further relates to a method for the automated positioning of an inflation tool on a tire valve of a rim along a longitudinal axis of the tire valve using a tool according to the invention.

Description

The invention relates to a tool, a system and a method for the automated positioning of an inflation tool on a tire valve of a rim.

When handling car tires at the dealer or in the workshop, semi-automatic tools are used for various work steps, some of which still require manual assistance from staff. One example is the inflation tool, which controls the inflation process itself - the controlled introduction of air into the cavity between the tire and the rim - but which requires the manual positioning of the valve attachment. For the production of large quantities, the positioning of such a valve attachment is programmed into the movement sequence of a robot arm according to the state of the art and does not require individual recognition. Here, too, there is the problem that the rotational orientation of the valve is usually not known. The state of the art here is a so-called pump bell that is placed over the gap between the rim and the tire and which brings the tire to the desired air pressure under high pressure. However, such a system is extremely costly.

In the context of a dealer or workshop, the automatic placement of the valve attachment is technically demanding because frequently changing models are to be operated with one device. Not only the position of the valve must be recognized, but also its orientation so that the valve attachment can be automatically placed at the correct angle. According to the state of the art, this step is carried out by hand in workshops.

The manual insertion of the inflation tool into the tire valve is also a monotonous task and must be accomplished even if there is a possible shortage of personnel.

The US 5 392 122 A describes a method for accurately determining the dimensions of surfaces of an object, in particular during machining of the object. Also disclosed are machine tools, turning and milling machines which contain the necessary components to carry out the said measurements without the use of additional equipment.

In the US 4 561 776 A an electro-optical sensor is removably mounted on a conventional machine tool, for example at a location where a tool is normally mounted, to detect the condition of a workpiece. The signals received by the sensor probe can be transmitted to a control point either by radio telemetry or via electrical and/or fiber optic lines operatively connected to the sensor probe. Alternatively, robot-assisted positioning of the probes is disclosed.

The US 2008 119 962 A1 discloses an improved vehicle tire changing system for servicing a vehicle wheel assembly consisting of a tire and a rim configured with one or more imaging sensors to accurately measure distances, dimensions, and characteristics of features associated with a vehicle wheel assembly during a tire mounting, tire demounting, or tire mounting change process.

Finally, the EP1995083A1 a method and a device for determining geometric dimensions of a motor vehicle wheel (rim/tire assembly) by contactless scanning, wherein the wheel is fastened to wheel receiving means of a tire mounting machine, that at least one light beam is emitted onto the wheel or at least a part of the wheel, wherein the light beam reflected at the impact surface is detected, and wherein the directions of the emitted and reflected light beams are evaluated to determine the shape and/or position of the respective impact surface on the wheel.

The invention is based on the object of enabling an automatic, orthogonal alignment (perpendicular to the attachment surface) of the inflation tool above the valve of a motor vehicle tire, without having to previously program the geometry or type of tire model or other information about the tire or rim.

The object is achieved in terms of the device by the features of independent patent claims 1 and 4 and in terms of the method by the features of independent patent claim 5. Further expedient embodiments of the invention are the subject of the dependent patent claims.

To solve this problem, a tool for the automated positioning of an inflation tool on a tire valve of a rim is proposed, wherein the tool has an inflation tool and a camera and wherein the tool has a defined spatial relationship between the optical axis of a lens of the camera and an axis of action of the inflation tool.

The defined spatial relationship between the two named axes is unchangeable and is known to a tool controller.

In a preferred embodiment, the camera and the inflation tool and thus the axis of action of the inflation tool and the optical axis of the lens of the camera are arranged in opposite directions to each other, so that with a rotation at an angle of 180° and optionally an additional linear movement of the tool, the same spatial orientation can be established between the camera and a filling adapter of the inflation tool that is to be placed on the valve.

It can be provided that the axis of action of the tool and the optical axis of the lens are identical or offset and arranged parallel.

Other spatial relationships between the camera and the inflation tool are also conceivable.

A tire valve according to the invention has a valve body and a nut. To position the inflation tool on the tire valve, the inflation tool is aligned along a longitudinal axis of a tire valve of a rim, wherein the longitudinal axis runs through the center of the valve body.

It can be provided that the inflation tool has a sleeve, a filling adapter movably arranged inside the sleeve and a sensor arranged inside the sleeve which detects the contact between the filling adapter and a tire valve.

The sensor can in particular be an inductive proximity sensor (micro switch). The contact force can be defined via an adjustable end stop before a contact disk connected to the filling adapter or formed on the filling adapter is moved within the switching distance of the inductive proximity sensor. The proximity sensor feeds its signal into the robot controller or into a central PLC in order to stop the movement of the robot arm upon contact. When the signal is fed into the robot controller, safety-relevant information, i.e. the intended collision, can be processed directly and the robot can be stopped more quickly without incurring cycle time and transmission time of the PLC and between the robot and the PLC as reaction time.

Furthermore, it can be provided that the filling process is started, since the filling adapter and valve have a tight and defined contact.

The object is further achieved by a system for the automated positioning of an inflation tool on a tire valve of a rim, comprising a movable robot arm, a wheel attachment and a robot end effector which is designed as a tool according to the invention.

It can be provided that the wheel attachment is mounted so that it can rotate. This can advantageously save working space.

If the wheel mount is not rotatable, it is intended that the robot end effector can move around the wheel mount.

Advantageously, the system according to the invention also has at least one control unit for controlling the tool. This can be integrated into the control of the robot arm or integrated separately via a programmable logic controller (PLC).

The robot end effector is designed to be moved by the robot arm to the action point of a rim attached to the wheel attachment.

1. a. Positionierung einer mit einem Roboterarm verbundenen Kamera über der Felge mittels einer Steuereinheit bis sich die Lage des Reifenventils im Raum und die optische Achse eines Objektivs der Kamera in einer Ebene befinden, wobei die Steuereinheit Bilddaten der Kamera empfängt;
2. b. Ausrichtung der Kamera durch die Steuereinheit auf Grundlage der von der Kamera übermittelten Bilddaten derart, dass sich die optische Achse des Objektivs der Kamera in einer Linie mit dem Ventileinsatz des Ventilkörpers befindet;
3. c. Ausrichtung des Aufpumpwerkzeuges durch die Steuereinheit auf Grundlage der ermittelten Position und Orientierung der Kamera derart, dass eine Wirkverbindung zwischen dem Reifenventil und dem Aufpumpwerkzeug herstellbar ist; und
4. d. Herstellung einer Wirkverbindung zwischen dem Reifenventil und dem Aufpumpwerkzeug.

The object is further achieved by a method for the automated positioning of an inflation tool on a tire valve of a rim along a longitudinal axis of the tire valve with a tool according to the invention, the tire valve comprising a valve body and a nut, wherein the longitudinal axis runs through the center of the valve body, wherein the valve body has a threaded sleeve and a valve insert arranged inside the threaded sleeve, comprising the steps

1. a. Positioning a camera connected to a robot arm over the rim by means of a control unit until the position of the tire valve in space and the optical axis of a lens of the camera are in one plane, whereby the control unit receives image data from the camera;
2. b. Alignment of the camera by the control unit on the basis of the image data transmitted by the camera such that the optical axis of the camera lens is in line with the valve insert of the valve body;
3. c. Alignment of the inflation tool by the control unit based on the determined position and orientation of the camera such that that an operative connection can be established between the tyre valve and the inflation tool; and
4. d. Establishment of an operative connection between the tire valve and the inflation tool.

It can be provided that the valve insert is detected by means of a neural network in order to position the camera above the rim. The control unit receives image data from the camera and automatically detects the valve insert, in particular the valve tappet, using the neural network.

To position the camera, it can also be provided that the rim and the camera are moved towards each other until the distance between the valve insert and the optical axis of the camera lens is minimal. In embodiments in which the rim is rotatably mounted, this can be done by rotating the rim. The camera is moved to a defined position in which, for a defined number of product variants of rims, the valve becomes visible after a maximum rotation of the positioning table of 345°. The rotatably mounted rim is positioned by detecting the valve insert in the camera image so that the valve is optimally positioned within the radius of movement of the robot arm. Rims with a diameter of 14 inches to 23 inches are preferably processed using the method according to the invention.

In a next step of the method according to the invention, the camera is aligned in such a way that the optical axis of the camera lens is in line with the valve insert of the valve body. In other words, the optical axis of the camera lens is aligned at right angles to the attachment surface. An inflation tool in the same position can be moved from this position to the valve attachment or valve in a later step.

In particular, the robot arm moves radially around the detected valve insert and the images captured by the camera are permanently transmitted to the control unit.

The orientation of the camera is also determined using automatic image recognition via the neural network, more precisely using U-net from the grayscale image transmitted by the camera. The images transmitted by the camera are continuously analyzed while the camera is moving.

To align the optical axis of the camera lens in line with the valve insert, the camera is preferably moved in a circular path around the valve insert until the position of the valve insert and the optical axis of the lens coincide.

In particular, the valve insert and/or the outer edge of the threaded sleeve of the valve body and/or the upper edge of the tire valve nut and/or the side edges of the nut are detected by means of a neural network. It is also conceivable that other prominent optical landmarks than those mentioned are detected, for example those that were installed in advance for the purpose of detection.

When the characteristics of the valve are detected, positioning is carried out based on the setpoints generated from the time the characteristics are detected.

Preferably, a center point is determined from the image coordinates of the outer edge of the threaded sleeve of the valve body and/or the upper edge of the tire valve nut and/or the side edges of the nut and the center point(s) are compared with the position of the valve insert. The distance calculation is carried out continuously, preferably at least 60 times per second. The robot is moved freely and the optical system or the control unit calculates continuously. The optical system or the control unit indicates the direction of movement for the robot or causes the robot to stop when the target position is reached.

The position of the valve insert is defined by the center of the valve insert.

It can be provided that the movement of the camera is interrupted as soon as the distance of one or more of the determined center points to the position of the valve insert is minimal. Alternatively, it can be provided that the movement of the camera is interrupted as soon as the sum of the distances of several of the determined center points to the position of the valve insert is minimal.

It can also be provided that the camera is moved by the control unit back to the movement path on which the distance of one or more of the determined center points to the position of the valve insert or the sum of the distances of several of the determined center points to the position of the valve insert was minimal.

To align the inflation tool, the determined position and orientation of the robot arm is used by the control unit to align the inflation tool with the same position and orientation. The inflation tool is aligned by the same or another robot arm.

It can be provided that an operative connection between the tire valve and the inflation tool is established by a defined movement of the robot arm connected to the camera.

The defined movement can be a rotation, for example a 180° rotation and a subsequent linear movement of the robot arm.

Preferably, the linear movement of the robot arm is interrupted as soon as a sensor in the inflation tool registers the connection between the inflation tool and the tire valve. To do this, the contact force can be defined using an adjustable end stop before a contact disk connected to the filling adapter or formed on the filling adapter is moved within the switching distance of the sensor, in particular the inductive proximity sensor. The sensor feeds its signal into a central PLC to stop the movement of the robot arm upon contact.

Furthermore, it can be provided that the filling process is started, since the filling adapter and valve have a tight and defined contact.

Tire valves on which an inflation tool with the tool according to the invention and/or the system according to the invention and/or the method according to the invention can be positioned can be, for example, standard Schrader valves and/or TPMS valves (tire pressure monitoring system valves) and/or rubber valves.

The tool, system and method according to the invention provides an automated, cost-effective solution for positioning an inflation tool on a tire valve of a rim while maintaining consistent quality. The possibility of automation also enables personnel savings.

• 1: eine Seitansicht eines erfindungsgemäßen Systems;
• 2: eine weitere schematische Ansicht eines erfindungsgemäßen Systems;
• 3: eine Detailansicht eines Aufpumpwerkzeuges eines erfindungsgemäßen Werkzeuges im Längsschnitt
• 4a: Beispielhafte Momentaufnahme der Kamera eines erfindungsgemäßen Werkzeuges während der Durchführung des erfindungsgemäßen Verfahrens (Blick auf das Reifenventil einer Felge schräg); und
• 4b: Beispielhafte Momentaufnahme der Kamera eines erfindungsgemäßen Werkzeuges während der Durchführung des erfindungsgemäßen Verfahrens (Blick auf das Reifenventil einer Felge orthogonal).

The invention is explained in more detail below using embodiments and associated drawings.

• 1 : a side view of a system according to the invention;
• 2 : another schematic view of a system according to the invention;
• 3 : a detailed view of an inflation tool of a tool according to the invention in longitudinal section
• 4a : Example snapshot of the camera of a tool according to the invention during the implementation of the method according to the invention (oblique view of the tire valve of a rim); and
• 4b : Example snapshot of the camera of a tool according to the invention during the implementation of the method according to the invention (orthogonal view of the tire valve of a rim).

1 and 2 show views of a system according to the invention, wherein 1 a side view and 2 illustrate a further view. The system according to the invention has a tool 1 according to the invention, a robot arm 7 connected to it and a wheel attachment 8. An inflation tool 2 and a camera 3 are arranged on the tool 1. The inflation tool 2 has an axis of action A _A , while a lens of the camera 3 has an optical axis A _K.

The axis of action A _A of the inflation tool 2 and the optical axis A _K of the lens of the camera 3 have a defined and unchanging spatial relationship to one another. In the embodiment shown, the two axes are arranged parallel to one another and offset. In the embodiment shown, the camera 3 and the inflation tool 2 point in opposite directions.

The control unit for controlling the tool 1 is integrated into the control of the robot arm 7 or separately via a programmable logic controller (PLC).

In 2 Also visible are the rim F and the tire valve V, on which the inflation tool 2 can be positioned by means of the illustrated system according to the invention.

3 shows a detailed view of an inflation tool 2 of a tool 1 according to the invention in longitudinal section.

The inflation tool 2 has a sleeve 4, a filling adapter 5 movably arranged inside the sleeve 4 and a sensor 6 arranged inside the sleeve 4, which detects the contact between the filling adapter 5 and a tire valve (in 3 not shown) is detected.

The sensor 6 can in particular be an inductive proximity sensor (microswitch). The contact force is defined via an adjustable end stop 9 before a contact disk 10 connected to the filling adapter 5 or formed on the filling adapter 5 is moved within the switching distance of the inductive proximity sensor 6. The proximity sensor 6 feeds its signal into the robot control in order to stop the movement of the robot arm when it comes into contact with the tire valve.

Also in 3 The axis of action A _A of the inflation tool 2 is visible.

4a and 4b show exemplary snapshots of the camera of a tool according to the invention during the implementation of the method according to the invention, wherein in 4a a camera image, i.e. a view of the tire valve V of a rim F, is shown at a moment in which the camera has not yet reached its target position, i.e. in which the optical axis A _K of the lens is not yet orthogonal to the longitudinal axis of the valve V running through the center point of the valve insert V12. 4b a camera image, i.e. a view of the tire valve V at the moment when the optical axis A _K of the lens is aligned orthogonally to the longitudinal axis of the valve V passing through the center point of the valve insert V12.

In the 4a and 4b it can be seen that the tire valve V has a valve body V1 and a nut V2, wherein the valve body V1 in turn has a threaded sleeve V11 and a valve insert V12 arranged inside the threaded sleeve V11. Distinctive optical points of the nut V2, which can be used to carry out the method according to the invention, are the upper edge V21 of the nut V2 and the side edges V22 of the nut V2.

After the camera 3 has been positioned above the rim F in a first step when carrying out the method according to the invention in such a way that the position of the tire valve V in space and the optical axis A _K of the lens of the camera are in one plane, in a second step the camera 3 is aligned by the control unit in such a way that the optical axis A _K of the lens of the camera 3 is in line with the valve insert V12 of the valve body V1.

For this purpose, the valve insert V12 and/or the outer edge of the threaded sleeve V11 of the valve body V1 and/or the upper edge V21 of the nut V2 of the tire valve V and/or the side edges V22 of the nut V2 are detected by means of a neural network.

A center point is determined from the image coordinates of the outer edge of the threaded sleeve V11 of the valve body V1 and/or the upper edge V21 of the nut V2 of the tire valve V and/or the side edges V22 of the nut V2 and the center point(s) are compared with the position of the valve insert V12. The distance is calculated continuously, preferably at least 60 times per second. The optical system or the control unit indicates the direction of movement for the robot or causes the robot to stop when the target position is reached. The target position is reached when the distance of one or more of the determined center points to the valve body V11 is minimal.

Due to the design, the center point of the upper edge V21 of the nut V2 and the center point of the side edges V22 of the nut V2 are usually almost on top of each other.

The position of the valve insert is defined by the center of the valve insert.

At the 4b In the snapshot shown, the target position has been reached because all determined center points lie one above the other, i.e. they have a minimum distance to each other and in particular to the valve insert V12.

List of reference symbols

1

Tool

2

Inflation tool

3

camera

4

Sleeve

5

Filling adapter

6

sensor

7

Robot arm

8th

Wheel attachment

9

adjustable end stop

10

Contact disc

A.A.

Axis of action of the inflation tool

AC

optical axis of the camera lens

F

rim

V

Tire valve

V1

Valve body

V11

Threaded sleeve

V12

Valve insert

V2

Mother

V21

Upper edge of the nut

V22

Side edges of the nut

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 5392122 A [0005]
• US 4561776 A [0006]
• US 2008119962 A1 [0007]
• EP1995083A1 [0008]

Claims (13)

Tool (1) for the automated positioning of an inflation tool (2) on a tire valve (V) of a rim (F), comprising an inflation tool (2) and a camera (3), wherein the tool (1) has a defined spatial relationship between the optical axis (A _K ) of a lens of the camera (3) and an axis of action (A _A ) of the inflation tool (2). Tool after Claim 1 , wherein the axis of action (A _A ) of the inflation tool (2) is aligned in the opposite direction to the optical axis (A _K ) of the lens of the camera (3). Tool after Claim 1 or 2 , wherein the inflation tool (2) has a sleeve (4), a filling adapter (5) movably arranged inside the sleeve (4) and a sensor (6) arranged inside the sleeve (4) which detects the contact between the filling adapter (5) and a tire valve (V). System for the automated positioning of an inflation tool (2) on a tire valve (V) of a rim (F), comprising a movable robot arm (7), a wheel attachment (8) and a robot end effector which serves as a tool (1) according to one of the Claims 1 until 3 is trained. Method for the automated positioning of an inflation tool (2) on a tire valve (V) of a rim (F) along a longitudinal axis of the tire valve (V) with a tool (1) according to one of the Claims 1 until 3 , the tire valve (V) having a valve body (V1) and a nut (V2), the longitudinal axis running through the center of the valve body (V1), the valve body (V1) having a threaded sleeve (V11) and a valve insert (V12) arranged inside the threaded sleeve (V11), comprising the steps of a. positioning a camera (3) connected to a robot arm (7) above the rim (F) by means of a control unit until the position of the tire valve (V) in space and the optical axis (A _K ) of a lens of the camera (3) are in one plane, the control unit receiving image data from the camera (3); b. aligning the camera (3) by the control unit on the basis of the image data transmitted by the camera (3) such that the optical axis (A _K ) of the lens of the camera (3) is in line with the valve insert (V12) of the valve body (V1); c. Alignment of the inflation tool (2) by the control unit on the basis of the determined position and orientation of the camera (3) such that an operative connection can be established between the tire valve (V) and the inflation tool (2); and d. Establishing an operative connection between the tire valve (V) and the inflation tool (2). Procedure according to Claim 5 , in which the valve insert (V12) is detected by means of a neural network in order to position the camera (3) above the rim (F). Procedure according to Claim 6 , in which the rim (F) and the camera (3) are moved towards each other until the distance between the valve insert (V12) and the optical axis (A _K ) of the lens of the camera (3) is minimal. Method according to one of the Claims 5 until 7 , in which, in order to align the optical axis (A _K ) of the lens of the camera (3) in line with the valve insert (V12), the camera (3) is moved on a circular path around the valve insert (V12) until the position of the valve insert (V12) and the optical axis (A _K ) of the lens coincide. Procedure according to Claim 8 , in which the valve insert (V12) and/or the outer edge of the threaded sleeve (V11) of the valve body (V1) and/or the upper edge (V21) of the nut (V2) of the tire valve (V) and/or the side edges (V22) of the nut (V2) are detected by means of a neural network. Procedure according to Claim 9 , in which a center point is determined from the image coordinates of the outer edge of the threaded sleeve (V11) of the valve body (V1) and/or the upper edge (V21) of the nut (V2) of the tire valve (V) and/or the side edges (V22) of the nut (V2) and the center point(s) are compared with the position of the valve insert (V12). Procedure according to Claim 10 , in which the movement of the camera (3) is interrupted as soon as the distance of one or more of the determined center points to the position of the valve insert (V12) is minimal. Method according to one of the Claims 5 until 11 , in which an operative connection between the tire valve (V) and the inflation tool (2) is established by a defined movement of the robot arm (7) connected to the camera (3). Procedure according to Claim 12 , in which the defined movement of the robot arm (7) is interrupted as soon as the connection between the pump and the pump tool (2) and tire valve (V).

Images