DE102015220614A1 - Method for checking existing features on a component - Google Patents

Abstract

The present invention relates to a method for testing at least two features of a component by means of a multi-axis manipulator. The axes of the manipulator are provided with force and / or torque sensors. The method comprises performing a fixing movement, which is suitable for holding the at least two features of the component. Furthermore, the method comprises a control of the manipulator for a movement of the manipulator, wherein the movement for applying forces to the at least two features of the component is suitable. Based on detected forces and / or moments acting on the axes of the manipulator, properties of the at least two features of the component are determined.

Description

1. Technical area

The present invention relates to a method for testing at least two features of a component by means of a multi-axis manipulator, as well as a corresponding system for testing a component.

2. Technical background

Robots are freely programmable, program-controlled handling devices. The actual robot mechanics is often referred to as a manipulator. This can consist of a number of movable, chained together links or axes, wherein the movement of the individual axes can be effected by a targeted control of corresponding drives, thus enabling a desired movement of the manipulator.

Robots can be used, for example, in assembly or manufacturing processes, for example to move or edit components by means of an end effector. Such a component may for example be a display, which is provided on both sides with a protective film. In an automated assembly and / or manufacturing process, it may be necessary to check the presence of the films before a certain processing step. This is usually done by means of external sensors, which detects whether the films are present, and can give feedback to a corresponding control of the manipulator.

It is an object of the present invention to provide a method by which properties of features of a component can be effectively tested.

These and other objects, which will become apparent from the following description, are achieved by a method of inspecting a component according to claim 1 and a system for inspecting a component according to claim 14.

3. Content of the invention

The present invention relates to a method for testing at least two features of a component by means of a multi-axis manipulator. In particular, properties of the features of the component can be determined or checked, such as the presence of certain features, such as certain objects on a component. For example, the presence of two pins that are to extend from a component can be tested. The component can be formed in one piece, or consist of several individual components.

The method for testing at least two features of a component comprises performing a fixing movement, which is suitable for holding the at least two features of the component. For this purpose, the manipulator can be controlled by a controller accordingly. In this case, for example, attempts can be made to hold two objects of the component, regardless of whether they are present or not. The fixing movement may be a previously defined movement with respect to the features to be tested, which is performed program-controlled. For example, the fixing movement can be performed by the manipulator. In general, the fixing movement can be configured as desired, provided that it is suitable for holding features of a component. Thus, the fixing movement may include gripping, clamping, threading, etc. Holding the component need not involve a firm fixation. Particularly preferably, the method comprises testing (exactly) two features of a component.

Furthermore, the method comprises a control of the manipulator for a movement of the manipulator, wherein the movement for applying forces to the at least two features of the component is suitable. This can preferably be done by means of a corresponding control. For this purpose, the individual drives of the manipulator can be controlled in order to bring about a desired movement of the manipulator and in particular of a tool center point of the manipulator. An actual movement of the manipulator does not have to take place: If, for example, due to the fixing movement a contact between the manipulator, component and the environment has been produced, by driving the manipulator, a force can be applied to the at least two held features of the component, wherein a movement of the tool center however, the manipulator fails.

Furthermore, the method comprises detecting forces and / or moments acting on the axes of the manipulator. For this purpose, a corresponding means or measuring means for detecting these acting on the axes of the manipulator forces and / or moments can be provided. For example, motor currents or drive currents of the manipulator can be read out and analyzed here in order to obtain measurement data on the forces and / or moments acting. The means may in particular include force and / or moment sensors. Preferably, this detection takes place during the activation of the manipulator. In particular, forces can be monitored which result from the activation of the manipulator. It can In particular, the direction of the resulting forces and / or moments are detected.

Furthermore, the method comprises determining properties of the at least two features of the component based on the detected forces and / or moments. This can preferably be done by means of a corresponding control. A feature of a feature may include, for example, the presence of a feature or an object of the component. It can be checked, for example, whether films are present on a display, whether holes have a desired size and / or are present, whether adhesive bonds have a desired elasticity, an undesired edge has been successfully removed, etc.

Thus, it can be efficiently checked by means of a manipulator whether, for example, two objects of a component are present or correctly arranged or not. This is done essentially by monitoring forces and / or moments acting on the axes of the manipulator. Further sensors, as provided on or in the manipulator means or measuring means for detecting the forces and / or moments, is not necessary.

Preferably, the axes of the manipulator are provided with force and / or torque sensors. The detection of forces acting on the axes of the manipulator forces and / or moments is preferably carried out by means of these force and / or torque sensors. The sensors may be based on strain gauges located on the axes of the manipulator, such as an articulated arm robot. Strain gauges allow a particularly precise detection of the forces acting. During a load, corresponding measured values for forces and moments or torques can be derived based on detected strains or compressions. Preferably, all axes of the manipulator are provided with such force and / or torque sensors. These sensors also allow effective control and monitoring of the manipulator. For example, the manipulator can be controlled in a force-controlled mode, such as in particular a compliance mode, and particularly preferably by means of a force, impedance, an admittance, a position or a torque control. The compliance mode may allow the manipulator or the corresponding controller to perceive the environment of the manipulator and to respond to environmental influences.

In the case of a compliance or impedance regulation, the connection between force and position can be regulated during object contact. The compliance can describe in particular how the manipulator reacts to occurring contact forces, or how this is counteracted. The impedance or admittance can represent a quantitative measure of the compliance control.

According to the selected control, the position control may be made taking into consideration a contact force change, or the contact force control may be controlled based on the position change. The actuators of the manipulator can be controlled based on desired forces by the force or torque control. For this purpose, an adjustment can be made with actually occurring actual forces or actual torques and according to the control difference between desired and actual forces or torques, the control takes place. Likewise, a force, impedance, admittance or position based on this control principle can be used to achieve the most accurate target values.

Preferably, determining properties of the at least two features of the component comprises comparing the detected forces and / or moments with a predetermined expectation value. The predetermined expectation value may be, for example, an expected force resulting from the application of forces to the at least two features of the component when the at least two features of the component are held due to the fixing movement. If this expected force now fails, since the at least two features of the component are not kept, for example, it can be determined that the at least two features of the component are not present.

The manipulation of the manipulator preferably takes place for a movement of a manipulator and in particular for a movement of the tool center point of the manipulator along a first spatial direction. For example, the manipulator is controlled such that the tool center point is to move along a vertical coordinate axis. Furthermore, the manipulator is preferably operated in a force-controlled mode, in particular a soft-switched module, so that movements of the manipulator and in particular movements of the tool center point of the manipulator can be caused to passively orthogonal to the first spatial direction. By soft switching of the manipulator, the tool center point, for example, move freely in a horizontal plane when corresponding forces act on it. Particularly preferably, a force component acts orthogonal to the first spatial direction on the manipulator and in particular on the tool center of the manipulator, along which the movement is to take place, if not all of the at least two features of the component are held as a result of the fixing movement.

For example, the manipulator may be controlled to apply force to the component in a vertical spatial direction while at the same time being operated in the soft-switched mode such that horizontal movements of the component are yieldingly carried by the manipulator. In an exemplary example, one of two features of the component to be tested may be present, but a second one may not, and the manipulator may only hold the existing feature due to the fixing movement. Since the second feature is missing and not held, this can result in a torque which causes a rotation of the component. This rotation has a component in the horizontal plane, and thus can be carried by the manipulator since it is operated in the soft-switched mode. Based on the resulting sensed forces and / or moments acting on the axes of the manipulator, it can then be determined that one feature is present but a second is absent.

Preferably, determining characteristics of the at least two features of the component comprises determining whether the component has been moved as a result of driving the manipulator. In particular, it is preferably determined whether the component has been moved, tilted or rotated. This can be done by evaluating the detected forces and / or moments, and allow a conclusion on the characteristics of the features of the component. For example, a displacement of the component may result if all or none of the features of the component to be tested are present, depending on the configuration. A tilting can z. B. result, if two but not all of three features to be tested are present, the three features to be tested preferably not consecutively exist or should be present. A rotation can z. B. result, if only one of at least two features to be tested is present. Thus, depending on the application, specific criteria for testing features of a component can be created individually. In general, a turning or tilting about a rotational or tilting axis can take place. This axis may be defined by one or more of the existing features to be tested.

In particular, preferably, the component does not move as a result of the activation of the manipulator when the at least two features of the component are held as a result of the fixing movement. Then, a presence of the at least two features of the component can be determined.

In particular, the component preferably moves as a result of the activation of the manipulator, if not all of the at least two features of the component are held as a result of the fixing movement. In this case, the component can move due to the activation of the manipulator, if none of the at least two features of the component is held as a result of the fixing movement. Thereby, the absence of one of the at least two features can be determined. Furthermore, the component may rotate as a result of the activation of the manipulator, if one but not all of the at least two features of the component are held as a result of the fixing movement. Thereby, a presence of the one feature of the component can be determined, which is held as a result of the fixing movement. In particular, the component may tilt as a result of the activation of the manipulator when two but not all of at least two or at least three features of the component are held as a result of the fixing movement.

Preferably, the fixing movement is performed by means of a fixing device. The fixing device may be provided on the manipulator and preferably be an end effector or a part of an end effector of the manipulator. Alternatively, the fixing device may be externally provided and preferably suitable for releasably holding the at least two features of the component. In this case, the externally provided fixing device can achieve a frictional connection to the component by holding a feature of the component. The externally provided fixing device, for example, be firmly connected to the environment. Thus, depending on the nature of the component this can be checked efficiently.

The manipulation of the manipulator for movement of the manipulator preferably takes place such that a predefined limit force is not exceeded when applying forces to the at least two features of the component. A limitation of a tensile force, for example, can protect the component from damage.

Furthermore, the present invention relates to a system for testing a component, and in particular for testing at least two features of a component. The system comprises a multi-axis manipulator whose axes are provided with a means for detecting forces and / or moments and in particular force and / or moment sensors. The means need not necessarily be arranged directly spatially on the axes, although this is preferred. Further, the system includes a controller configured to perform one of the methods described above. Preferably, the system is free of external sensors for testing for the presence of features of the component.

Furthermore, the present invention relates to the use of the above-described method or the system for testing described above Presence of at least two features of a component.

4th embodiments

In the following, the present invention will be described in detail with reference to the accompanying drawings. The same parts are designated by the same reference numerals. It shows:

1 a system for testing a component according to an embodiment;

2 the system of 1 according to a further embodiment;

3 an external fixing device according to an embodiment;

4 a system for testing a component according to an embodiment; and

5 the system of 4 according to a further embodiment.

In the 1 schematically is a system for testing a component 30 shown. The component comprises a carrier 31 which is a first and second object 32 . 33 supports. The system includes a multi-axis manipulator 10 and an external fixing device 20 , On the multi-axis manipulator 10 Force-moment sensors are provided which are on the axes or joints of the manipulator 10 detect acting forces and torques.

In the illustrated embodiment is to be checked automatically and without the use of additional, externally provided sensors, whether the features or objects 32 and 33 of the component 30 exist or not. Furthermore, preference is given to a lack of one of the features or objects 32 . 33 to determine which of the objects 32 . 33 is missing or available. The following is the first step of a successful test with reference to 1 and subsequently the expiration of a non-successful audit with reference to 2 described.

At the beginning of the exam will be the carrier 31 of the component 30 by means of an end effector 11 of the manipulator 10 resorted. Then the component becomes 30 to the fixing device 20 emotional. Preferably, for this purpose, the dimensions of the component 30 and in particular the expected position of the objects 32 . 33 known or provided in a corresponding control. The fixing device 20 then performs a fixing movement, which for holding the objects 32 . 33 of the component 30 suitable is. In the illustrated embodiment, both are objects 32 . 33 present, so that the fixing device has these features 32 . 33 stops as a result of the fixing movement.

Now the manipulator 10 switched soft, allowing movements of the end effector 11 in the x-direction can be caused by external influences. The manipulator 10 regulates its drives based on detected forces and moments such that the end effector 11 a force acting in the x direction follows. In particular, the manipulator 10 thereby being switched for rotation of the end effector about the y direction, which is orthogonal to the x and z directions. Subsequently, the manipulator 10 for a movement of the end effector 11 controlled in z-direction. This ultimately forces on the two characteristics 32 . 33 of the component 30 Applied as these continue from the fixator 20 being held. Because both features 32 . 33 are present and held, there is no movement of the end effector 11 , This can be determined by monitoring the force-moment sensors. Thus, as a result, it is determined that both objects 32 . 33 of the component 30 available.

For example, if none of the objects 32 . 33 would exist, could be the end effector 11 or a manipulator flange due to the activation of the manipulator 10 proceed unhindered in z-direction. From such a linear movement of the end effector 11 and the resulting readings of force-moment sensors could then be determined as the result that none of the objects 32 . 33 on the component 30 is available.

In the 2 is a similar situation as in 1 shown. However, here, in comparison to the 1 on the component 30 the first object 32 , As a result of the fixing movement, which of the fixing device 20 is performed, thus only the second object 33 held by the fixing device. If now the manipulator 10 is driven, for a movement of the end effector 11 along the z-direction, with the manipulator 10 Furthermore, as described above, for a movement along the x-direction or a rotation about the y-axis is switched soft, can by means of the force-moment sensors on the manipulator 10 a corresponding resultant torque can be detected. Due to this torque can thus be determined that the object 32 is missing and only the object 33 is available.

Likewise, with reference to 1 , z. For example, check whether there are connections between the objects 32 . 33 and the carrier 31 of the component 30 have a desired elasticity. This can be done by the wearer 31 by means of the end effector 11 and then the manipulator be driven such that a force on the component 30 acts in z-direction. If there is a different elasticity of these connections, this results in a corresponding torque, which on the axes of the manipulator 10 can be detected.

In the 3 is a fixing device 20 which, for example, the fixing device 20 of the 1 and 2 can be. The fixing device 20 consists of a fixed bracket 21 and a fixed fixing element 22 which is attached to the fixed bracket 21 is appropriate. Furthermore, the fixing device comprises 20 a drive element 23 , which by means of a movement device, in particular a linear axis, an upper movable fixing element 24 with two attached pins 25 . 26 move, in particular can move linearly. Between the pins 25 . 26 and the fixed fixing element 22 objects can be kept.

Furthermore, in the 3 a component 30 represented, for example, a display 31 can be with it applied protective films. Lugs extend 32 . 33 the protective film from the display 31 path.

In the illustrated embodiment, automatically the presence of these films or tabs 32 . 33 being checked. The films or tabs 32 . 33 are features of the component to be tested, ie the display 31 , This is the display 31 to the fixing device 20 introduced. Subsequently, by means of the drive 23 the fixing pins 25 . 26 so relative to the fixed fixing element 22 moved that in between the tabs of the slides 32 . 33 , as shown, are trapped (if any). Subsequently, by means of a manipulator, the display can be tried 31 to remove from the device. Because the tabs of the slides 32 . 33 however, from the fixer 20 held substantially no movement takes place, preferably no movement of the component 30 , If none of the film tabs 32 . 33 would be present, a parallel displacement of the component could be performed and detected by means of the manipulator. For example, if only one foil flap 32 would be present, the display would 31 around the fixing point of the film tab 32 rotate when using a center of the component 30 Attempting manipulator would try this from the fixer 20 to remove in z-direction. For this purpose, the manipulator is in a soft-switching mode, so that a rotation of the display is carried in the x-direction.

• 1. Wenn eine Verschiebung des Manipulatorflansches bzw. des Bauteils 30 stattfindet, oder eine erwartete Gegenkraft ausbleibt, ist keines der Objekte 32, 33 vorhanden.
• 2. Wenn eine Rotation des Manipulatorflansches oder ein Moment in Richtung der Fixiereinrichtung 20 gemessen wird, ist lediglich eines der Objekte 32, 33 vorhanden. Die Richtung des Moments zeigt dabei an, welches der Objekte 32, 33 vorhanden ist.
• 3. Wenn der Manipulator 10 annähernd in derselben Position verbleibt, oder eine Kraft bzw. ein Moment in Richtung der Fixiereinrichtung 20 auftritt, sind beide Objekte 32, 33 vorhanden.

Based on the detected forces / moments during the activation of the manipulator 10 can be measured for a movement of the component in the z-direction, the following scenarios can be distinguished as a result of an evaluation:

• 1. If a displacement of the manipulator flange or the component 30 takes place, or an expected counterforce is missing, is none of the objects 32 . 33 available.
• 2. If a rotation of the manipulator flange or a moment in the direction of the fixing device 20 is measured is only one of the objects 32 . 33 available. The direction of the moment indicates which of the objects 32 . 33 is available.
• 3. If the manipulator 10 remains approximately in the same position, or a force or a moment in the direction of the fixing device 20 occurs, both are objects 32 . 33 available.

In the 4 another embodiment of the present invention is shown. The representation is analogous to the 2 and 3 but no external fixing device is provided here. It should again be checked automatically, if the objects 32 . 33 of the component 30 available.

A mass part 31 of the component 30 lies on the floor, or a table, a workbench, a work platform, etc. A manipulator 10 gets to the component 30 introduced. Preferably, the dimensions of the component are also here 30 and in particular the expected position of the objects 32 . 33 known or provided in a corresponding control. Subsequently, by the manipulator 10 performed a fixing movement, wherein attempts are made by means of two holding devices 12 . 13 the objects 32 . 33 to grab or hold. The holding devices 12 . 13 can be active or passive, and for example, active as a gripper or passively as hooks or pins exist o. Ä.

Subsequently, a movement of the manipulator flange 14 performed in the z-direction, so that a force F _{1, Z} on the manipulator flange 14 acts. This results in forces, each on the objects 32 . 33 of the component 30 act (F _{2, Z} , F _{3, Z} ). By monitoring the on the axes of the manipulator 10 acting forces and / or moments can be found that no forces or moments act in the x direction. Thus it can be determined - according to the forces acting in the z-direction - whether none or both of the features 32 . 33 available.

In the 5 is a similar situation as in the 4 shown. However, here, in comparison to the presentation is missing 4 , the second feature 33 of the component 30 , If now the manipulator 10 is controlled such that the manipulator flange 14 to move in the z-direction, only a force F _{2, Z} acts on the component 30 or on the object 32 , Because the gripper 13 no feature engages results in a torque which, for example, by the illustrated force F _{1, X} on the manipulator flange 14 results. Likewise, also corresponding torques on the other axes of the manipulator 10 Act. Because of these torques it can be determined that only the object 32 but not the object 33 on the component 30 is available.

Regarding the 4 and 5 the skilled person understands that the length of the illustrated force arrows is only schematic and should not represent exact proportions.

LIST OF REFERENCE NUMBERS

10

manipulator

11

end effector

12, 13

holders

14

Manipulatorflansch

20

external fixing device

21

fixed bracket

22

fixed fixing element

23

driving element

24

movable fixing element

25, 26

pins

30

component

31

Carrier, display

32, 33

Feature, object, foil flap

Claims (16)

Method for testing at least two features ( 32 . 33 ) of a component ( 30 ) by means of a multi-axis manipulator ( 10 ), the method comprising: a) performing a fixing movement, which is for holding the at least two features ( 32 . 33 ) of the component ( 30 ) suitable is; b) activating the manipulator for a movement of the manipulator ( 10 ), wherein the movement for applying forces to the at least two features ( 32 . 33 ) of the component ( 30 ) suitable is; c) detecting on the axes of the manipulator ( 10 ) acting forces and / or moments; and d) determining properties of the at least two features ( 32 . 33 ) of the component ( 30 ), based on the detected forces and / or moments. The method of claim 1, wherein determining characteristics comprises comparing the detected forces and / or moments with a predetermined expectation value. Method according to claim 1 or 2, wherein the driving of the manipulator ( 10 ) for a movement of the manipulator ( 10 ) and in particular for a movement of a tool center point of the manipulator ( 10 ) along a first spatial direction, and the manipulator ( 10 ) is operated in a force-controlled mode, in particular a soft-switched mode, so that movements of the manipulator ( 10 ) and in particular movements of the tool center of the manipulator ( 10 ) can be caused to passively orthogonal to the first spatial direction. Method according to claim 3, wherein a force component orthogonal to the first spatial direction on the manipulator ( 10 ) and in particular to the tool center of the manipulator ( 10 ), if not all of the at least two features ( 32 . 33 ) of the component ( 30 ) are held as a result of the fixing movement. Method according to one of claims 1 to 4, wherein the determining of properties comprises determining whether the component ( 30 ) due to the activation of the manipulator ( 10 ), and in particular determining whether the component ( 30 ) was moved, tilted or rotated. Method according to one of claims 1 to 5, wherein the component ( 30 ) due to the activation of the manipulator ( 10 ) is not moved when the at least two features ( 32 . 33 ) of the component ( 30 ) are held as a result of the fixing movement, and preferably a presence of the at least two features ( 32 . 33 ) of the component ( 30 ) is determined. Method according to one of claims 1 to 6, wherein the component ( 30 ) due to the activation of the manipulator ( 10 ), if not all of the at least two features ( 32 . 33 ) of the component ( 30 ) are held as a result of the fixing movement. Method according to claim 7, wherein the component ( 30 ) due to the activation of the manipulator ( 10 ), if none of the at least two characteristics ( 32 . 33 ) of the component ( 30 ) is held as a result of the fixing movement, and preferably a presence of none of the at least two features ( 32 . 33 ) is determined. Method according to claim 7, wherein the component ( 30 ) due to the activation of the manipulator ( 10 ) rotates and / or tilts when one but not all of the at least two features ( 32 . 33 ) of the component ( 30 ) are held as a result of the fixing movement, and preferably a presence of the one feature ( 32 . 33 ) of the component ( 30 ), which is held as a result of the fixing movement. Method according to one of claims 1 to 9, wherein the fixing movement by means of a fixing device ( 11 . 20 ) is carried out. The method of claim 10, wherein the fixing device on the manipulator ( 10 ) and preferably an end effector ( 11 ) or a part of an end effector of the manipulator ( 10 ) is and/ or wherein the fixing device ( 20 ) is provided externally and preferably for detachably holding the at least two features ( 32 . 33 ) of the component ( 30 ) suitable is. Method according to one of the preceding claims, wherein the driving of the manipulator ( 10 ) for a movement of the manipulator ( 10 ) such that a predefined limiting force when applying forces to the at least two features ( 32 . 33 ) of the component ( 30 ) is not exceeded. Method according to one of the preceding claims, wherein the axes of the multi-axis manipulator ( 10 ) are provided with force and / or torque sensors. System for testing at least two characteristics ( 32 . 33 ) of a component ( 30 ), comprising a multi-axis manipulator ( 10 ) whose axes are provided with a means for detecting forces and / or moments and in particular force and / or moment sensors, and a controller which is adapted to perform a method according to any one of claims 1-13. The system of claim 14, wherein the system is free of external sensors to check for presence of features ( 32 . 33 ) of the component ( 30 ). Use of a method according to one of claims 1 to 13 or a system according to one of claims 14 or 15 for checking for the presence of at least two features ( 32 . 33 ) of a component ( 30 ).

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