DE102019204606A1 - Method for operating a sensor for generating surface measurement data of a workpiece and arrangement with such a sensor - Google Patents

Abstract

The invention relates to a method for operating a sensor (1) which is designed to generate surface measurement data of a workpiece (5), in particular for the purpose of determining the coordinates of a surface of the workpiece (5), with the following method steps: a) receiving a Position signal from the controller (3), the position signal from the controller (3) of the sensor (1) signaling that the sensor (1) is at an intended position for the generation of a set of surface measurement data, b ) wireless transmission of a data generation trigger signal from the controller (3) to the sensor (1), c) generation of the set of surface measurement data by the sensor (1) triggered by the data generation trigger signal, d) storage of the set of surface measurement data by the sensor (1) in a data memory of the sensor (1) and wireless transmission of a confirmation signal from the sensor (1) to the controller (3), with the confirmation signal it is signaled that the sensor (1) has generated the set of surface measurement data, the set of surface measurement data or a part of the set of surface measurement data being read from the data memory of the sensor (1) and being transferred from the sensor (1) to one of the sensor ( 1) remote facility is sent.

Description

The invention relates to a method for operating a sensor which is designed to generate surface measurement data of a workpiece, in particular for the purpose of determining the coordinates of a surface of the workpiece. The invention also relates to an arrangement for generating surface measurement data of a workpiece, in particular for the purpose of determining the coordinates of a surface of the workpiece, the arrangement having a sensor for generating the surface measurement data and a control of the sensor.

Various types of sensors for detecting workpiece surfaces and generating corresponding surface measurement data are known in particular from coordinate metrology. Coordinates of the surface of the workpiece can be obtained from the primary surface measurement data through a later evaluation of the data. While in classic coordinate metrology, surface points of the workpiece are touched with tactile sensors so that contact is made between the sensor and the surface, various types of non-contact sensors are also used that generate measurement data without contact with the surface of the workpiece. Examples of non-contact sensors are capacitive sensors, inductive sensors, magnetic sensors and optical sensors. While with tactile sensors e.g. the coordinates of the contact point between the sensor and the surface of the workpiece can be determined directly by a position measuring system of the coordinate measuring machine, non-contact sensors generate measurement data of a primary measurement signal such as an electrical capacitance, an electrical inductance, a magnetic field strength, a distance to the surface and / or image data which coordinates of the workpiece surface can be determined indirectly by evaluating the surface measurement data. It is also common to take the position of the sensor into account while generating the surface measurement data. In this application, the term “position of the sensor” is also understood to mean the orientation. This is based on the idea that, in general, the relative position of sensor and workpiece surface and the alignment must be taken into account if the coordinates are to be determined from the surface measurement data. In special cases, the position can be subject to boundary conditions (such as an unchangeable alignment of the sensor) so that not all six degrees of freedom of the movement of the sensor relative to the workpiece have to be explicitly taken into account.

A determination of the coordinates of a surface of the workpiece can also be used when relative shape features such as a gap width or a flush are determined from the surface measurement data. For example, the gap width is a statement about the coordinates at opposite edges of a gap and can be understood directly as a coordinate in a coordinate system whose origin is at an edge of the gap.

In more general terms, however, the invention relates as an alternative or in addition to the determination of coordinates from the surface measurement data to the determination of features of the surface from the surface measurement data. Features (e.g. also referred to as “features” in body inline measurement technology) and in particular shape features are, for example, characteristic surface areas such as holes, bolts, recesses and undercuts. In particular, their position can be determined from the surface measurement data. When evaluating the surface measurement data with regard to features, a distinction can be made between discrete features, for example their position in a coordinate system (such as the coordinate system of the workpiece), and relative features such as the relationship between different features or parts of features. Examples of corresponding determinations from the surface measurement data are the mentioned gap width, but also the parallelism of surface areas or the roundness.

Furthermore, as an alternative or in addition, it can also be determined from the surface measurement data whether the surface meets specifications, in particular quality specifications. For example, scratches can be determined and it can be determined whether the surface or a surface area has a predetermined color.

A special field of application of the invention is in-line body measurement technology, in which bodies, in particular of vehicles, are measured in-line, that is, during the process of manufacturing the body or body parts, or at least the measurement data are recorded.

The invention relates in particular to sensors measuring in a contactless manner and especially to optical sensors.

The optical sensors include, for example, hand-operated and machine-operated sensors, ie the position of the optical sensor relative to the workpiece can be changed and set manually and / or by means of a machine. With optical sensors there are also different principles for recording surface measurement data. For example, in line scanners, electromagnetic radiation is projected onto the workpiece surface in the area of at least one line and an image of the reflected Radiation recorded. Alternatively, in particular, predefined patterns of electromagnetic radiation of a different type than merely consisting of lines can be projected onto the workpiece surface. In all cases, the projection can optionally be changed over time. Furthermore, alternatively or additionally, irradiation of the workpiece surface by the sensor can be dispensed with or the sensor or at least one associated irradiation device irradiate the workpiece surface in a different way than in the form of a pattern, i.e. at a given point in time surface areas of the workpiece surface oriented in the same direction become homogeneous, for example irradiated. In all cases, the electromagnetic radiation used to irradiate the workpiece surface can be in the visible wavelength range and / or outside the visible wavelength range. The type of irradiation and the detection device of the optical sensor are matched to one another.

If the optical sensor records at least one image of the surface of the workpiece, it can in particular be a one-dimensional image, a two-dimensional image or (e.g. when using the method of measuring the transit time of electromagnetic radiation) a three-dimensional image. It is also possible to record a plurality of images simultaneously and / or successively by the sensor and to determine coordinates of the workpiece surface from this plurality of images. Technical practice is e.g. the use of the stereo principle, which makes it possible to determine three-dimensional coordinates of the workpiece surface from two images recorded from different angles. The principle of triangulation is similar with a directed arrangement of irradiation and image recording device.

The above description of the measuring principles of non-contact and, in particular, optical sensors is not to be understood as conclusive, i.e. in connection with the invention can, for. B. other non-contact sensors can be used. However, the invention relates in particular to the use of optical sensors that generate surface measurement data of a workpiece surface, with the surface measurement data not being partially or completely evaluated by the sensor itself. The surface measurement data are therefore to be transmitted from the sensor to another location and in particular to another device (such as a data memory). The sensor can for example have a housing in which all devices of the sensor are arranged.

DE 10 2010 018 979 A1 describes a method for determining the 3D coordinates of the surface of an object. Object data is generated by a hand-held scanner, for example, and transmitted wirelessly to a controller. The wireless transmission can take place by radio waves or by optical transmission, such as infrared radiation. The publication mentions that errors in the transmission of the object data can be automatically recognized and rectified. In this way, it can be prevented that object data not or not correctly recorded or transmitted, for example due to interference signals from the environment, has to be recorded again with a corresponding additional effort and corresponding additional costs. There are also cases in which measurements cannot be repeated because the device under test or the measuring device are no longer available. Errors can in particular be eliminated by retransmitting data or data packets that were not transmitted or not transmitted correctly.

It is also off DE 10 2015 204 473 A1 a device for contactless three-dimensional measurement of components is known. In particular in the context of the measurement of body shells of vehicles in a production line, it is described that an optical sensor is moved with a manipulator, in particular an industrial robot. The optical sensor is arranged on a sensor base of the manipulator and has an electronic image recording element and at least one light source. An evaluation unit for measurement data recorded by the optical sensor is provided on the sensor base. The evaluation unit can considerably reduce the amount of data to be transmitted away from the sensor base. In this context, it is also described that the device can be designed to be fail-safe in that the evaluation unit has a memory for measurement results. A transmitter for wireless transmission of data from the evaluation unit to a receiver can be provided on the sensor base. Furthermore, a docking station can be provided, wherein data can be transmitted after the sensor base has been docked and an energy store can be charged on the sensor base.

While DE 10 2010 018 979 A1 it enables errors in the transmission of the object data to be corrected in that data or data packets that have not been transmitted or not transmitted correctly are transmitted again. The present invention is based on the object of reliably designing a sequence when operating a sensor.

It is proposed to use or provide a control of the sensor which is arranged remotely from the sensor. This means in particular that the control is not moved, or at least not moved in the same way as the sensor, when the sensor is brought into an intended position for the generation of a set of surface measurement data of a workpiece.

Furthermore, there is a signal connection between the controller and the sensor, which is configured at least partially and / or at least temporarily for wireless transmission of a signal from the controller to the sensor and for the wireless transmission of a signal from the sensor to the controller. Temporary means that it may temporarily also be possible that at least one signal is not transmitted wirelessly between the controller and the sensor. For example, the sensor can be temporarily docked to a docking station and, in this state, a non-wireless signal transmission between the controller and the sensor can take place. If, on the other hand, the sensor is in a measuring position in which it detects a workpiece and generates corresponding surface measurement data, then a wireless signal transmission takes place between the control and the sensor. Wireless means that there is no continuous signal line connection between the sensor and the controller. A signal line is not only understood to mean an electrical line, but also any other type of signal line, such as a fiber optic cable for the transmission of optical signals. The term “wireless” can therefore also be used instead of “wireless”. Wireless or wireless does not mean, however, that above all also within the sensor, within an arrangement with the sensor and with at least one device permanently connected to the sensor, within the controller and within an arrangement with the controller and at least one relative to the controller immovable device no line sections are used for local transmission of signals. The wireless signal transmission is particularly advantageous in an industrial manufacturing environment. It does not restrict the movement of the sensor by a continuous signal line connection and damage to a signal line connection in particularly endangered areas can be avoided by dispensing with signal line connections in the endangered areas. Signal line connections, in particular on a robot arm to the end of which the sensor is attached, are also exposed to loads and can be damaged. There is therefore in particular a wireless transmission of signals between an arrangement with the sensor and at least one device permanently connected to the sensor on the one hand and an arrangement with the controller and at least one device immovable relative to the controller or the controller itself on the other.

The local distribution of the sensor and control has the advantage that, particularly in body inline measuring technology, the sensor can be attached in suitable measuring positions without the control. In particular, the sensor forms a smaller and more compact structural unit than in combination with its controller. In addition, the sensor alone can be designed in such a way that it consumes less energy than the combination of controller and sensor. The energy supply of the sensor can therefore be designed so that it has to provide less energy.

It is also proposed that the control signal to the sensor that the sensor is generating surface measurement data of a workpiece. Such a data generation trigger signal, which is transmitted from the controller to the sensor, can trigger the generation of the surface measurement data directly or indirectly. In the case of immediate triggering, the generation of the surface measurement data begins immediately upon receipt and due to the reception of the data generation trigger signal by the sensor. In the case of indirect triggering, the signal can be processed by the sensor and, in particular due to a logic implemented in the sensor, there is also the possibility that the sensor does not start generating the surface measurement data or does not start immediately. E.g. the sensor can first check whether at least one further prerequisite for starting the generation of the surface measurement data is met. Alternatively or additionally, the sensor can check or take into account whether or that an error is present, e.g. a functional error of an irradiation device of the sensor with which the surface of a workpiece to be detected is to be irradiated.

Another possibility of an error relates to the operating state of a data memory of the sensor, which will be discussed in more detail below. If the storage of the surface measurement data to be generated in a data memory of the sensor would not be possible without having to delete or overwrite other already stored data, the sensor can optionally determine this and e.g. send a corresponding status signal.

As a rule, however, the reception of the data generation trigger signal transmitted wirelessly from the controller to the sensor results in the sensor starting to generate the surface measurement data. As the sensor receives the trigger signal, it does not have to check whether it is in the correct position to generate the surface measurement data. This can be left to sensor-external devices, such as the control in particular. The sensor therefore has a correspondingly reduced functionality, which in turn reduces its energy requirement. In particular, if, as is preferred, in the measuring position of the sensor, any line connection between the movable sensor and a stationary base is dispensed with, it is advantageous if the energy requirement of the sensor is low.

The sensor can therefore be combined with a local energy store which is movable together with the sensor and which is not connected to the stationary base via an electrical line. The energy store supplies the sensor with electrical energy for the acquisition of the surface measurement data, for the execution of the logic optionally implemented in the sensor and for the signal processing by the sensor, in particular the processing of received signals and the sending of signals. A sensor-external transmitting and receiving module is preferably combined with the sensor, which is moved along with the sensor. This module is used to receive and send signals that are output by the sensor or are intended for reception by the sensor. This can in particular be a radio module, for example according to the Bluetooth standard, a WLAN module or a module according to another radio standard such as 4G or 5G. The transmitter / receiver module can draw energy for its operation from the same energy store as the sensor. Alternatively, the module can have a different energy supply than the sensor. Furthermore, instead of a single module for receiving and transmitting signals, separate devices can alternatively be provided for the purposes mentioned.

It is further proposed that the sensor store the surface measurement data generated on the basis of a detection of a workpiece in a data memory of the sensor and wirelessly transmit a confirmation signal to the controller when a set of surface measurement data has been generated. As a result, the sensor signals to the controller that at least part of the detection of the workpiece has been completed. In particular, the control can determine from this that the detection of the workpiece in the current position of the sensor has been completed and can initiate and / or trigger a movement of the sensor at another location. E.g. the sensor can then be brought into a different intended position for detection of the same workpiece or a different workpiece, or the sensor can be brought into a service position in which other functions are carried out, e.g. the charging of the mentioned energy store, which is moved along with the sensor, and / or a data transmission of the surface measurement data generated by the sensor. This means that the surface measurement data do not necessarily have to be sent wirelessly from the sensor to a device remote from the sensor, even if wireless transmission of the surface measurement data generated by the sensor is preferred.

The position of the sensor at the beginning of a time interval of the generation of surface measurement data does not have to coincide with the position at the end of the time interval, even if there are numerous situations in which a fixed position of the sensor during the time interval of generation of surface measurement data is advantageous and the invention is carried out accordingly. A set of surface measurement data is generated in this time interval. The term “set of surface measurement data” is used repeatedly in the following. If the position at the end of the time interval does not match that at the beginning, a workpiece is scanned, for example. This includes that part of the sensor is in a fixed position during the time interval and only another part of the sensor is moving. For example, optics of the sensor for capturing image data can move while an irradiation device of the sensor for irradiating the surface of the workpiece to be captured is at rest. Conversely, an irradiation device of the sensor can continuously irradiate different areas of the surface of the workpiece to be detected and an image detection device of the sensor can rest during this and thus always detect the same area of the workpiece.

1. a) Empfangen eines Positions-Signals durch eine Steuerung des Sensors, wobei durch das Positions-Signal der Steuerung des Sensors signalisiert wird, dass sich der Sensor an der beabsichtigten Position für die Erzeugung eines Satzes von Oberflächenmessdaten befindet,
2. b) drahtloses Übertragen eines Datenerzeugungs-Auslösesignals von der Steuerung zu dem Sensor,
3. c) Erzeugen des Satzes von Oberflächenmessdaten durch den Sensor ausgelöst durch das Datenerzeugungs-Auslösesignal,
4. d) Speichern des Satzes von Oberflächenmessdaten durch den Sensor in einem Datenspeicher des Sensors und drahtloses Übertragen eines Bestätigungs-Signals von dem Sensor zu der Steuerung, wobei durch das Bestätigungs-Signal signalisiert wird, dass der Sensor den Satz von Oberflächenmessdaten erzeugt hat,

wobei der Satz von Oberflächenmessdaten oder ein Teil des Satzes von Oberflächenmessdaten aus dem Datenspeicher des Sensors ausgelesen und von dem Sensor zu einer von dem Sensor entfernten Einrichtung gesendet wird.In particular, the following is proposed: a method for operating a sensor which is designed to generate surface measurement data of a workpiece, in particular for the purpose of determining the coordinates of a surface of the workpiece, with the following method steps:

1. a) receiving a position signal by a controller of the sensor, the position signal signaling the controller of the sensor that the sensor is at the intended position for the generation of a set of surface measurement data,
2. b) wireless transmission of a data generation trigger signal from the controller to the sensor,
3. c) generating the set of surface measurement data by the sensor triggered by the data generation trigger signal,
4. d) the sensor stores the set of surface measurement data in a data memory of the sensor and wireless transmission of a confirmation signal from the sensor to the controller, the confirmation signal signaling that the sensor has generated the set of surface measurement data,

wherein the set of surface measurement data or a part of the set of surface measurement data is read out from the data memory of the sensor and sent from the sensor to a device remote from the sensor.

1. a) durch die Steuerung ein Positions-Signal zu empfangen, wobei durch das Positions-Signal der Steuerung des Sensors signalisiert wird, dass sich der Sensor an einer beabsichtigten Position für die Erzeugung eines Satzes von Oberflächenmessdaten befindet,
2. b) ein Datenerzeugungs-Auslösesignals drahtlos von der Steuerung zu dem Sensor zu übertragen,
3. c) ausgelöst durch das Datenerzeugungs-Auslösesignal durch den Sensor den Satz von Oberflächenmessdaten zu erzeugen,
4. d) den Satz von Oberflächenmessdaten durch den Sensor in einem Datenspeicher des Sensors zu speichern und ein Bestätigungs-Signals von dem Sensor drahtlos zu der Steuerung zu übertragen, wobei durch das Bestätigungs-Signal signalisiert wird, dass der Sensor den Satz von Oberflächenmessdaten erzeugt hat,

wobei der Sensor ausgestaltet ist, den Satz von Oberflächenmessdaten oder ein Teil des Satzes von Oberflächenmessdaten aus dem Datenspeicher des Sensors auszulesen und von dem Sensor zu einer von dem Sensor entfernten Einrichtung zu senden.Furthermore, it is proposed: An arrangement for generating surface measurement data of a workpiece, in particular for the purpose of determining the coordinates of a surface of the workpiece, the arrangement having a sensor for generating the surface measurement data and a control of the sensor arranged remotely from the sensor, and the arrangement being configured:

1. a) to receive a position signal by the controller, the position signal signaling the controller of the sensor that the sensor is at an intended position for the generation of a set of surface measurement data,
2. b) wirelessly transmit a data generation trigger signal from the controller to the sensor,
3. c) to generate the set of surface measurement data triggered by the data generation trigger signal by the sensor,
4. d) to store the set of surface measurement data by the sensor in a data memory of the sensor and to transmit a confirmation signal wirelessly from the sensor to the controller, the confirmation signal being used to signal that the sensor has generated the set of surface measurement data,

wherein the sensor is designed to read the set of surface measurement data or a part of the set of surface measurement data from the data memory of the sensor and to send it from the sensor to a device remote from the sensor.

In particular, the arrangement can be designed to carry out steps a) to d) of the above-mentioned method. Furthermore, the arrangement can be configured to carry out the method in one of the specific configurations that are described in this description.

• Ausgeben eines Positionierungs-Signals von der Steuerung des Sensors zu einer Positionierungseinrichtung, um den Sensor in die beabsichtigte Position für die Erzeugung eines Satzes von Oberflächenmessdaten zu bringen.

For example, the sensor can be moved by a person. If, on the other hand, the movement of the sensor is carried out controlled by a machine, it is preferred that the following step is carried out before step a):

• Outputting a positioning signal from the controller of the sensor to a positioning device in order to bring the sensor into the intended position for the generation of a set of surface measurement data.

It corresponds to this that the arrangement is designed to output a positioning signal from the control of the sensor to a positioning device in order to bring the sensor into the intended position for the generation of the set of surface measurement data. While the positioning signal generally causes the positioning to move the sensor, the position signal signals that the sensor is at an intended position for the generation of a set of surface measurement data.

The position signal can optionally be used to indicate the position at which the sensor is located. This includes the possibility of signaling in which direction the sensor is oriented.

The sensor can e.g. be attached to an arm of a robot and the positioning signal can then be output to a motion controller of the robot. The robot can optionally be part of the arrangement.

The advantage of the output of the positioning signal from the control of the sensor is that the control can carry out the positioning and, after receiving the confirmation signal from the sensor, can optionally continue to control the movement of the sensor.

In general, the positioning device does not have to be part of the arrangement. In specific refinements of the arrangement, however, the positioning device is part of the arrangement. E.g. the positioning device may be part of a robot (e.g. an articulated arm robot) to which the sensor is attached. However, other positioning devices with other movement mechanisms are also possible. One example is a coordinate measuring machine in portal design or gantry design. In the case of a robot, it can also be a freely moving robot that does not have a stationary base. An example of a free-moving robot is a self-driving vehicle.

The position signal can e.g. B. merely have the information that the sensor is at an intended position for the generation of a set of surface measurement data. Therefore, if the sensor is operated by hand, for example, the operator who moves the sensor can actuate an actuating device of the sensor and thus initiate the transmission of the position signal to the controller. In the case of the machine-guided sensor, the transmission of the position signal to the controller can also be triggered by an operator. In all these cases the position signal can be transmitted from the sensor or another device to the controller. For example, a control panel with an actuating element can be provided for the operator, the actuation of which triggers the transmission of the position signal. In the case of the machine-guided sensor, however, it is preferred that the position signal is generated automatically when a device of the machine determines that the sensor is in the intended position or is about to be.

In particular, if the sensor is machine-operated, the position signal can already be transmitted to the controller when the sensor is still shortly before the intended measurement position. This takes into account, in particular, that the controller still needs time to receive and process the position signal and that the controller also needs time for the transmission and processing of the data generation trigger signal.

In particular, steps a) to d) can be carried out repeatedly for different intended positions. In this case, the controller can release, control and / or trigger the movement of the sensor to the next intended position, in particular after receiving the confirmation signal from the sensor. E.g. when released, a user or a movement device is signaled to move the sensor that the movement can now be carried out. When controlling the movement, the control of the sensor can also control the movement of the sensor e.g. control by activating a movement device or transmitting information to a movement controller. When it is triggered, unlike when it is released, it not only signals that the movement can now take place, but that the movement is triggered immediately.

The repetition of steps a) to d) does not exclude that between one execution of the steps and the next execution of the steps other actions are carried out and / or functions are carried out, such as the above-mentioned charging of an energy storage device of the sensor and / or the Transmission of surface measurement data from the sensor to the device remote from the sensor. This device can be a device that is separate from the controller and optionally also independent of the controller. Alternatively, it can be a device that is connected to the controller. E.g. The device can have a data memory of the controller and the controller can also control the evaluation of the surface measurement data, so that the coordinates of the surface of the workpiece are determined from the surface measurement data.

In particular, the set of surface measurement data or the part of the set of surface measurement data can be transmitted via a wireless transmission link from the sensor to the device remote from the sensor during a movement of the sensor to a subsequent intended position for the generation of a further set of surface measurement data. The arrangement can be designed accordingly. This has the advantage that it saves time. At the same time, the surface measurement data generated in the previous execution of steps a) to d) are stored in the data memory of the sensor and thus saved. Furthermore, the movement of the sensor into the following intended position is preferably only released, triggered and / or controlled by the controller when the confirmation signal has been transmitted from the sensor to the controller. In contrast, the wireless transmission of the data from the sensor to the remote device can already be started and optionally also completed while the sensor is still in the position in which the set of surface measurement data is or has been generated or in which the surface measurement data is generated continues or has ended.

Alternatively, the wireless transmission of the surface measurement data can begin as soon as part of the set of surface measurement data has been generated. However, there are situations, particularly in an industrial production environment, in which the surface measurement data cannot be transmitted or cannot be transmitted at the same data rate as they are generated. E.g. Radio data transmissions in an industrial manufacturing environment can be disrupted, for example by processes such as welding. It is also possible for the sensor to be in a position from which transmission of the data is hindered or prevented. E.g. For example, the sensor can be placed in areas between surfaces of the workpiece or behind the workpiece from which wireless transmission to the remote device is not possible.

As mentioned, the sensor can be an optical sensor. In one embodiment of the method and the arrangement, an optical sensor generates at least one image of the workpiece in step c), the image data of which is the set of surface measurement data or a part of the set of surface measurement data. The image is in particular a digital image. Pixels of the image can in particular be elements of a one-dimensional line image or, aligned in lines and columns, form a two-dimensional image matrix. The possibility has already been mentioned that transit time information of the measurement radiation and thus depth information can also be used. In this case, such runtime information can be assigned to an image pixel, for example. Optionally, the sensor can generate not only one image but, for example, a plurality of images simultaneously, for example in the case of a stereo image recording. In all cases, the time when an image or an image pixel was taken can also be recorded.

In one embodiment, the controller can transmit, in particular wirelessly, a value of an image generation parameter to the sensor before the sensor generates the set of surface measurement data that is triggered by the data generation trigger signal. The sensor then generates the set of surface measurement data according to the value of the imaging parameter. The image generation parameter can in particular be the parameter of a camera. The imaging parameter can therefore e.g. B. specify the length of the time interval over which a sensor element, such as a matrix element of a matrix of photodiodes, is irradiated with electromagnetic radiation emanating from the workpiece to be detected. This period is also known as the integration time for cameras. Another example of an image generation parameter is an amplification factor, also referred to as “gain”, with which electrical signals from the sensor elements of the camera are amplified. Yet another example is the shutter of a shutter optics of the camera. By transmitting a parameter value from the controller to the sensor for at least one image generation parameter, the camera can control the image generation. The sensor therefore does not have to determine image generation parameters itself (for example by evaluating a recorded image or based on information about the workpiece to be recorded) and image generation parameters adapted to the specific situation of the acquisition and / or the measurement task can also be set.

As an alternative or in addition, the controller can transmit a control signal for setting an irradiation device of the sensor to the sensor before the sensor generates the set of surface measurement data, which is triggered by the data generation trigger signal. The sensor then irradiates the workpiece while generating the at least one image in accordance with the setting of the irradiation device predetermined by the control signal. The irradiation device can also be a plurality of irradiation units, each of the irradiation units being adjustable independently or in connection with the other or the other of the irradiation units. The control signal preferably contains the information required for setting all existing irradiation units. At the beginning, examples for the irradiation of the workpiece to be detected were described. The setting of the irradiation device therefore leads to e.g. for setting at least one projected pattern, the intensity of the irradiation, the wavelength of the irradiation and / or the dimensions and / or position of the irradiated area. The irradiation duration can also be adjusted in this way. The setting of the irradiation device by means of a control signal transmitted by the controller has the advantage that the sensor itself does not have to have the functionality of selecting a setting adapted to the specific detection situation.

In particular, the sensor can be designed to determine that data already stored in the data memory of the sensor make up such a large proportion of the storage capacity of the data memory, i.e. a correspondingly large portion of the memory shows that the remaining storage capacity of the data memory is no longer sufficient for storing a subsequent and / or already performed acquisition of generated surface measurement data. These already stored data in the data memory of the sensor are data that have not yet been sent from the sensor to the device remote from the sensor or for which the sensor does not have the information that the data is from the remote device were received. In the first case, i.e. if the data have not yet been sent, the sensor can e.g. by an additional identification of this data. In a first embodiment the data can be deleted from the data memory as soon as they have been sent to the device remote from the sensor. Even without marking the data in the data memory as not sent, the data volume free for storing data in the data memory can therefore be used to determine whether new data to be stored can be completely stored.

However, deleting the stored data immediately after it has been sent has the disadvantage that the data cannot be sent again in the event of a disrupted or faulty transmission. It is therefore preferred that data stored in the data memory be marked so that the sensor can determine whether the data has been received from the remote device. E.g. A receipt confirmation signal can be sent to the sensor from the remote device for a transmitted data volume or data sub-volume. If it is determined from the receipt confirmation signal or upon receipt of the receipt confirmation signal from the sensor that the data volume or partial data volume has been received, the data in the data memory of the sensor can be deleted or the corresponding memory area can be marked so that it is overwritten with other data can be.

In particular, each of a plurality of images can be assigned a unique identifier. This makes it possible to uniquely identify each image using its identifier. The picture- Identifiers can then be used to determine which images have already been transmitted and / or received from the sensor to the remote device. In particular, the sensor generates the identifier or at least assigns the identifier to the respective image. In one embodiment, the identifier can be transmitted to the remote device and the remote device confirms to the sensor on the basis of the identifier that the image (ie the complete image data) has been received.

In general, the sensor can therefore determine, with regard to data still stored in the data memory of the sensor, whether the data may be deleted or overwritten because they have already been successfully transferred to the remote device. The fact that the data stored in the data memory has not yet been sent can therefore be carried out on the basis of an identification of the data or the storage area of this data or - in another embodiment - it can be concluded indirectly from the fact that the data is still in the data memory are stored. The fact that data still stored in the data memory can be deleted or overwritten can - in yet another embodiment - be concluded from the fact that at least one acknowledgment signal was received back from the remote device.

If the sensor determines that new data to be stored in the data memory cannot be saved or not completely saved because no correspondingly large free memory area is available, the sensor can send a corresponding status signal. As an alternative or in addition, a status signal can be sent by the sensor when sufficient storage volume is available for storing new data to be stored in the data in the data memory. E.g. the controller can therefore conclude from the absence of the status signal that there is no longer a sufficient data volume available.

The status signal can in particular be sent wirelessly. The receiver of the status signal is in particular the controller. Alternatively, the status signal can be sent to the remote device. The facility can then inform the controller.

In one embodiment of the method and the arrangement, the controller reacts to the receipt or the absence of the status signal, i. it reacts to the information that there is not a sufficiently large area of the data memory of the sensor available for storage during a subsequent and / or performed acquisition of generated surface measurement data. The reaction consists in particular in the fact that a planned operating sequence of the operation of the sensor is modified and / or interrupted and / or that the controller outputs a warning signal. The warning signal can in particular be output to the remote device. There are therefore various options for reacting to the information received. At least one of these possibilities is preferably implemented. The operating sequence can in particular be modified in such a way that a measurement of the workpiece is also carried out with the generation of a smaller amount of data, it being possible in particular to adhere to a modified measurement plan for the measurement of the workpiece. Alternatively or additionally, the controller can interrupt the operation of the sensor and e.g. wait to see whether further data are successfully sent from the sensor to the remote device so that a larger proportion of the available data volume of this data memory is available again for storage. From the warning signal, in particular with regard to the evaluation of the total surface measurement data transmitted to the remote device, the information can be taken that and optionally which desired measurement data have not or not yet been transmitted. This makes it possible, in particular, to change the evaluation of the measurement data transmitted as a whole.

• 1 schematisch einen Gelenkarmroboter, an dessen freiem Ende ein optischer Sensor befestigt ist, wobei sich der Sensor in einer Position zur Erfassung eines Werkstücks befindet,
• 2 ein Blockdiagramm, das schematisch Einrichtungen des Sensors, mit dem Sensor kombinierte Einrichtungen und Einrichtungen der Steuerung des Sensors zeigt, und
• 3 ein Flussdiagramm zur Darstellung von Verfahrensschritten bei der Erzeugung, Übertragung und Auswertung von Oberflächenmessdaten eines Werkstücks.

Embodiments of the invention will now be described with reference to the accompanying drawings. The individual figures in the drawing show:

• 1 schematically an articulated arm robot, at the free end of which an optical sensor is attached, the sensor being in a position for detecting a workpiece,
• 2 a block diagram schematically showing devices of the sensor, devices combined with the sensor and devices for controlling the sensor, and
• 3 a flowchart showing method steps in the generation, transmission and evaluation of surface measurement data of a workpiece.

The in 1 shown sensor 1 is an optical sensor that is attached to a free end of an articulated arm robot 7th is attached. The articulated arm robot 7th is on a stationary base 8th arranged. In the special embodiment it has five arm sections 9a to 9e on, each in pairs via a joint 10a to 10d are connected to each other and thus form a link chain. Further is the sensor 1 about another joint 10e with the arm section 9e connected, which is located at the free end of the articulated arm.

1 also shows schematically a workpiece 5 which is, for example, a body part for a Vehicle can act. In the upper right 1 is schematically a controller 3 of the sensor 1 shown, the signals to the sensor via a radio link, not shown 1 can transmit and signals from the sensor 1 can receive.

The articulated arm robot 7th has a motion control 11 on, via a signal connection (not shown) (in particular a line connection) with the controller 3 of the sensor 1 connected so that signals between the motion controller 11 and the control of the sensor 1 can be exchanged. In particular, the controller 3 Positioning signals to the motion controller 11 transmitted, which causes this to control a movement of the articulated arm accordingly. Not shown in 1 are corresponding actuators that control the movements of the arm sections 9b to 9e and the sensor 1 cause around the axes of rotation of the joints.

Unlike the schematic in 1 is shown, the controller can 3 as well as the motion control 11 in a stationary location, such as on the floor or near the floor or supported on the floor.

At the in 1 The arrangement shown is merely a special embodiment. A plurality of optical sensors can be provided instead of the optical sensor, or at least one other sensor, for example a contactless measuring sensor, can be provided instead of the optical sensor. Furthermore, instead of the articulated arm robot, another movement device can be provided which moves the at least one contactless measuring sensor. Furthermore, a different type of workpiece or a plurality of workpieces can be measured. In particular, a plurality of partial areas of the surface of the workpiece can be measured from at least one workpiece. For this purpose, the at least one sensor is moved by the movement device into different positions relative to the workpiece. In the position and / or starting from the position during the execution of a movement of the sensor, the workpiece is then detected, with at least one set of surface measurement data being generated in each case. The set or sets of surface measurement data can then be evaluated, for example, by the control of the sensor or by another device, and coordinates of the surface of the work piece (s) can be determined from the surface measurement data. The evaluation can in particular be carried out by a computer or a computer network.

This in 2 The block diagram shown shows a sensor on the right 21st , the e.g. in 1 shown sensor 1 is. The sensor 21st has, as is shown schematically by blocks, an irradiation device 22nd for uniform irradiation of the area of a measurement object to be detected, a pattern projection device 23 for the projection of radiation patterns onto an area of the workpiece to be detected, another device 24 , a sensor-internal energy supply device 25th to supply the electrical equipment of the sensor 21st with energy and a camera 26th to record the workpiece and generate corresponding surface measurement data. In the further establishment 24 For example, it can be a device that establishes a connection between the camera 26th and at least one of the facilities 22nd , 23 manufactures. In this way, for example, the irradiation of the measurement object with the recording of the respective image by the camera 26th be coordinated. In particular, in this way the irradiation can only take place during the image acquisition or a sequence of different irradiation patterns can be projected during the image acquisition. It concerns the establishment 24 therefore, for example, a corresponding control or control connection. Alternatively or in addition, it can be the case with the further device 24 a device for processing the energy supply for at least one of the devices 22nd , 23 act, for example to generate the required electrical supply voltage from the energy supply device 25th provided supply voltage.

At the camera 26th In particular, it can be a digital camera that generates two-dimensional images. The image data then represent the surface measurement data. For example, if one or more patterns are projected onto the imaged surface area of the workpiece during the recording of a camera image, the information can be obtained from the generally occurring change in the appearance of the projected pattern or patterns in the at least one recorded image can be determined over the course of the imaged surface area in the viewing direction of the camera, ie corresponding coordinates of the surface can be determined at least in the viewing direction of the camera. Other methods for determining the surface coordinates from the surface measurement data from sensors measuring in a contactless manner are known and are therefore not described in greater detail here. The irradiation facility 22nd serves for a more uniform irradiation of the surface area of the workpiece to be recorded by the camera. For example, surface areas are also irradiated in this way and reflected radiation from these surface areas can be detected by the camera, on which radiation or radiation with a low radiation flux density is not incident due to the pattern projection.

As part of the sensor 21st is also an image data memory 30th provided the one with the camera 26th connected is. The image data memory could be different from what is shown 30th directly - without using the camera 26th to communicate - with an interface or device of the sensor 21st for sending image data from the sensor 21st be connected. The image data store 30th can therefore be part of the camera 26th be or be a separate store.

2 also shows to the left of the sensor 21st in an area framed by a dashed line, three further devices that are not part of the sensor 21st are, however, fixed to the sensor during the detection of one or more workpieces 21st can be coupled. In particular, these devices in the embodiment of 1 on the same carrier at the free end of the articulated arm 7th or be arranged on the same carrier of another movement device as the sensor 1 .

The facilities are an energy storage device 27 for supplying electrical energy to the energy supply device 25th of the sensor 21st , a charger 28 to the energy storage 27 to charge on occasion, and a radio module 29 for the wireless transmission and reception of signals and optionally also for the transmission of data that the sensor 21st generated. The energy storage 27 is in particular then by means of the charging device 28 rechargeable when the combination of the sensor 21st and other facilities 27 and 28 has been moved to a service facility. For example, the service facility transmits electrical energy to the energy store 27 by converting electrical energy into magnetic field energy and from the charging device 28 the field energy is converted back into electrical energy by means of induction. In an alternative embodiment, the charging device 28 be connected to a charging connection of the service facility via electrical contacts. The service facility for charging the energy storage 27 is left in 2 and with the reference number 31 designated. Below the service facility 31 is a radio module 33 shown with the radio module 29 can communicate, ie signals to the radio module 29 send and signals and optionally data from the radio module 29 can receive. Like the rectangular frame around the service facility 31 and the radio module 33 indicates, these two devices can be arranged in a common technical unit. Alternatively, the service facility 31 and the radio module 33 be arranged separately and independently of one another.

Based on 3 an exemplary embodiment of a method sequence will now be described, for example in relation to the in 1 arrangement shown, which, for example, the in 2 Has illustrated facilities.

In step S1 starts the process with the output of a positioning signal from the controller 3 of the sensor 21st to a motion control 11 the movement device, which is able to do so, the sensor 21st to move. For the sake of simplicity and clarity, instead of a general movement device, the in 1 illustrated articulated arm 7th spoken. However, this does not restrict the exemplary embodiment to the movement by means of an articulated arm. Instead, another movement device can be used to move the sensor or a plurality of sensors. The control transmits the positioning signal 3 of the sensor 21st or the corresponding control of another embodiment sufficient information to the motion control 11 or the corresponding other motion control of another embodiment that allows motion control 11 allowed the sensor 21st to an intended position for the detection of a workpiece and therefore for the generation of a set of surface measurement data. In the next step S2 the articulated arm guides 7th this movement is controlled by the movement controller 11 out. In the next step S3 signals the motion control 11 by transmitting a position signal from the controller 3 that the intended position by the sensor 21st was achieved.

In the next step S4 transfers control 1 a data generation trigger signal via the radio module 33 to the radio module 29 from which it is to the sensor 21st is forwarded. The transmission takes place between the radio modules 33 , 39 wirelessly as a radio signal and the signal is transmitted from the radio module 29 to the sensor 21st via an electrical line connection and alternatively via an optical signal line connection. Not in 2 shown is a control logic that is part of the sensor 21st is available. Such a control logic can be implemented, for example, by a software-program-controlled computer or by an application-specific integrated circuit (ASIC). The control logic receives the data generation trigger signal and controls in the following step S5 the necessary facilities, such as the irradiation facility 22nd and the pattern projection device 23 , so that the area of the workpiece to be detected is irradiated. Optionally, the control logic of the sensor receives 21st in step S4 in addition to the data generation trigger signal, a control signal for setting the irradiation device 22nd and / or the pattern projection device 23 also for at least one imaging parameter of the camera 26th the associated value (e.g. duration of the exposure time interval and gain factor).

In the following step S6 the control logic controls the camera 26th so that at least one camera image is recorded from the surface area of the workpiece to be recorded. A corresponding set of surface measurement data (in the exemplary embodiment at least one camera image from the camera 26th ) generated. In the following step S7 or continuously during the step S6 the image data of the at least one camera image are read out and stored in an image data memory 30th the camera 26th saved. Unless the step S7 does not exist, follows the step S6 the step S8 . Otherwise, as in 3 shown, the step follows S8 on step S7 . In step S8 is controlled by the control logic or the camera 26th of the sensor 21st a confirmation signal is generated and via the module 29 to the module 33 and from this in turn to the controller 3 transfer. The confirmation signal signals that the sensor has generated the set of surface measurement data.

In one step S8 next step S9 the transmission of the data of the set of surface measurement data just stored is started. Alternatively, the data transmission from the sensor 21st already during the step S6 and / or the step S7 started and at least partially carried out during this time. Alternatively, the data transfer can also be started later. The data transfer takes place to one of the sensor 21st remote device, e.g. the controller 3 or to a data memory of the controller 3 . Furthermore, the remote device can be one of the controller 3 be an independent computer or an independent computer network. If the data transfer already occurred during one of the steps S7 to S9 begins, the data transmission takes place preferably wirelessly between the radio modules 29 , 33 instead of. Alternatively, the data of the set of surface measurement data just recorded can be used later, for example when the sensor 21st or the devices permanently connected to it are docked at a docking station and are transmitted there via electrical contacts.

In one step S7 or step S8 next step S10 provides the control logic 21st determines whether the data store 30th still sufficient without being in the data store 30th saved measurement data will be lost. For example, the control logic determines whether it is still in the data memory 30th stored data have already been sent to the device remote from the sensor or whether the data stored therein have not yet been received by the remote device. In step S10 can the sensor 21st and thus the control logic alternatively or additionally receive a signal from the device remote from the sensor which contains information about whether data and / or which data have already been received by the device. Data already received can be taken from the data memory 30th can be deleted or this data can be overwritten when storing another set of surface measurement data. On step S10 can be a step S11 in which the control logic of the sensor 21st a status signal via the radio modules according to a result of the determination 29 , 33 to the controller 3 transmits. The control can use the status signal 3 determine whether the sensor 21st is also able to generate and save measurement data according to a measurement plan. The controller can then 3 in one step S11 next step S12 or in the absence of a status signal, modify and / or interrupt a planned operating sequence of the operation of the sensor and / or output a warning signal.

After one of the steps S10 to S12 (this case is in 3 not shown) or after one of the steps S7 and S8 can start the procedure again with step S1 be repeated, however, the control 3 outputs another positioning signal. Alternatively, the procedure can begin with step S4 , ie, starting with the transmission of the data generation trigger signal, can be repeated so that the sensor generates a new set of surface measurement data without being moved to a different intended position. Optionally, however, other information for setting the at least one irradiation device of the sensor can be transmitted to the sensor and / or at least another value of an image generation parameter can be transmitted to the sensor.

List of reference symbols

1

sensor

3

control

5

workpiece

7th

Articulated arm robots

8th

Base

9

Arm section

10

joint

11

Motion control

21st

sensor

22nd

Irradiation facility

23

Pattern projection device

24

Setting up the sensor

25th

Energy supply device

26th

camera

27

Energy storage

28

Charging device

29

Radio module

30th

Image data storage

31

Service facility for charging the energy storage

33

Radio module

QUOTES INCLUDED IN THE DESCRIPTION

This list of the 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 assumes no liability for any errors or omissions.

Patent literature cited

• DE 102010018979 A1 [0011, 0013]
• DE 102015204473 A1 [0012]

Claims (12)

A method for operating a sensor (1) which is designed to generate surface measurement data of a workpiece (5), in particular for the purpose of determining the coordinates of a surface of the workpiece (5), with the following method steps: a) Receiving a position signal by a controller (3) of the sensor (1), the position signal of the controller (3) signaling that the sensor (1) is at an intended position for the generation of a set of Surface measurement data is located, b) wireless transmission of a data generation trigger signal from the controller (3) to the sensor (1), c) generation of the set of surface measurement data by the sensor (1) triggered by the data generation trigger signal, d) Storing the set of surface measurement data by the sensor (1) in a data memory (30) of the sensor (1) and wirelessly transmitting a confirmation signal from the sensor (1) to the controller (3), with the confirmation signal it is signaled that the sensor (1) has generated the set of surface measurement data, wherein the set of surface measurement data or a part of the set of surface measurement data is read out from the data memory (30) of the sensor (1) and from the sensor (1) to one of the sensor (1) remote device is sent. Procedure according to Claim 1 , wherein steps a) to d) according to Claim 1 performed repeatedly for different intended positions. Procedure according to Claim 2 wherein the set of surface measurement data or the part of the set of surface measurement data during a movement of the sensor (1) to a subsequent intended position for the generation of a further set of surface measurement data via a wireless transmission link from the sensor (1) to that of the sensor ( 1) remote facility is sent. Method according to one of the Claims 1 to 3 , wherein the sensor (1) is an optical sensor (1) which in step c) according to Claim 1 at least one image of the workpiece (5) is generated as the set of surface measurement data or as part of the set of surface measurement data. Procedure according to Claim 4 , wherein the controller (3) before step c) according to Claim 1 a value of an imaging parameter to the sensor (1) and the sensor (1) transmits the set of surface measurement data in step c) according to Claim 1 generated according to the value of the imaging parameter. Procedure according to Claim 4 or 5 , wherein the controller (3) before step c) according to Claim 1 a control signal for setting an irradiation device (22, 23) of the sensor (1) transmits to the sensor (1) and wherein the sensor (1) in step c) according to Claim 1 irradiates the workpiece (5) during the generation of the at least one image in accordance with the setting of the irradiation device (22, 23) predetermined by the control signal. Method according to one of the Claims 1 to 6th , wherein the sensor (1) determines that data already stored in the data memory (30) of the sensor (1) which have not yet been sent to the device removed from the sensor (1) or to which the sensor (1) has not has the information that the data has been received by the remote device, have such a large proportion of the storage capacity of the data memory (30) that the remaining storage capacity of the data memory (30) is no longer suitable for storage in a subsequent and / or already carried out acquisition of generated surface measurement data is sufficient, and wherein the sensor (1) sends out a status signal according to this determination. Procedure according to Claim 7 wherein the controller (3) modifies and / or interrupts a planned operational sequence of the operation of the sensor (1) after receiving the status signal and / or the controller (3) outputs a warning signal, in particular to the remote device. Arrangement for generating surface measurement data of a workpiece (5), in particular for the purpose of determining the coordinates of a surface of the workpiece (5), the arrangement having a sensor (1) for generating the surface measurement data and a controller (3) remote from the sensor (1) of the sensor (1) and wherein the arrangement is configured: a) to receive a position signal by the controller (3), the position signal of the controller (3) of the sensor (1) signaling that the Sensor (1) is at an intended position for the generation of a set of surface measurement data, b) wirelessly transmit a data generation trigger signal from the controller (3) to the sensor (1), c) triggered by the data generation trigger signal from the sensor (1) to generate the set of surface measurement data, d) to store the set of surface measurement data by the sensor (1) in a data memory of the sensor (1) and to send a confirmation signal from to transmit the sensor (1) wirelessly to the controller (3), with the confirmation signal being signaled that the sensor (1) has generated the set of surface measurement data, the sensor (1) being designed to use the set of Read out surface measurement data or a part of the set of surface measurement data from the data memory of the sensor (1) and send it from the sensor (1) to a device remote from the sensor (1). Arrangement according to Claim 9 or 10 wherein the sensor (1) is an optical sensor (1) which, triggered by the data generation trigger signal, generates at least one image of the workpiece (5) as the set of surface measurement data or as part of the set of surface measurement data. Arrangement according to Claim 10 , wherein the controller (3) is designed to transmit a value of an image generation parameter to the sensor (1), and the sensor (1) is designed to generate the set of surface measurement data corresponding to the value of the image generation parameter. Arrangement according to Claim 10 or 11 , wherein the controller (3) is designed to transmit a control signal for setting an irradiation device (22, 23) of the sensor (1) to the sensor (1), and wherein the sensor (1) is designed to hold the workpiece (5) to irradiate during the generation of the at least one image in accordance with the setting of the irradiation device (22, 23) predetermined by the control signal.

Images