DE102014117277B4 - carrier system - Google Patents

Abstract

Carrier system (1), comprising at least: - a position-stabilized component (2); - An imaging sensor (2a, 2b), which is adapted to continuously image signals of an environmental region of the carrier system (1) to detect; A position sensor (3); - Stabilizing means (5) for continuously stabilizing the position and / or orientation of the component (2) and the imaging sensor (2a, 2b) or at least its line of sight (LOS) in response to measurement signals (m_s) of the position sensor (3); and - image processing means (6) which are adapted to automatically determine an existing drift of the position sensor (3) from the image signals (v_s) detected by the imaging sensor (2a, 2b), wherein - the carrier system (1) is adapted thereto to automatically at least approximately correct and / or compensate the existing drift of the position sensor (3) determined by the image processing means (6) by the stabilization means (5).

Description

The invention relates to a carrier system, a method for determining a drift of a position sensor and a method for the continuous stabilization of the position and / or the orientation of a component.

Components, such as vision systems in or on moving supports, especially vehicles, ships, aircraft, buoys, masts, etc., should be stabilized with respect to their position and / or orientation, especially in the case of systems with small fields of view. If such a position stabilization is lacking, observation during the movement of the carrier or the base is not or only with difficulty possible or the visual range can be adversely affected. It is known to arrange such components in carrier systems which are provided with position sensors, in particular inertially measuring position sensors, preferably rotational position sensors (eg gyroscope sensors / mechanical gyro sensors) or yaw rate sensors (eg gyrometers), which monitor the movement of the line of sight (Line -Of-Sight / LOS). In this case, a downstream stabilization controller in conjunction with corresponding actuators for axis rotation (eg motors or the like) can compensate for the rotational movement such that, independently of the proper movements of the reference surface, ie. H. the attachment point of the vision system or the component or the carrier system to the carrier, the line of sight remains constant. Such carrier systems can be designed as part of the carrier or, z. B. by means of a suitable fastening device (mounting flange or the like) mounted on the carrier or connected to this.

There are position sensors, in particular rotational position sensors or yaw rate sensors of various technologies known. These include, for example, mechanical inertial gyros, fiber optic gyroscopes (FOG), laser gyros, or advanced micro-electro-mechanical systems (MEMS) gyroscopes / gyros.

However, such sensors show a - albeit small - self-drift. This self-drift depends on various characteristic, individual and dynamic factors. The used gyroscope technology, component scattering, temperatures or aging also play a role.

Due to this intrinsic drift, a line of sight of a vision system which is stabilized by means of a rotational position sensor or yaw rate sensor does not remain constant over a longer period, but gradually moves away from the original orientation.

In order to keep a set observation position constant, this drift should be prevented or eliminated. Systems known from practice compensate for drift by allowing the user to manually, e.g. B. separately for each axis, adjusts a correction. This procedure significantly reduces the drift. However, the drift of the position sensors also contains a component which varies, for example, as a function of the temperature, so that no constant success can be achieved over a longer period of time by means of the manually set drift compensation. The user must disadvantageously intervene again and compensate for the drift manually again. Since in particular rotational position sensors or yaw rate sensors are inertial measuring sensors, the earth rotation also has an influence on the drift. This influence is latitude-dependent and, with respect to the elevation angle, also dependent on the azimuthal line of sight. For example, the influence of the earth's rotation on the elevation axis reverses at an azimuthal rotation of 180 °. Thus, azimuthal rotation requires rebalancing the elevation drift.

An automatic drift compensation, in which the rotary drift is detected when a carrier system is at a standstill, is likewise already known. For this purpose, however, a standstill of the platform reference surface or the support (eg in the form of a land / sea / aircraft, a mast, a buoy, etc.) is mandatory. Likewise, in an automatic drift compensation, an external high-quality reference gyroscope system, such as a navigation system, be required.

In most cases, a standstill of the carrier or the carrier system at least during operation can not be achieved, since this may conflict with land or aircraft a given mission goal. On a maritime carrier, such as a boat, a ship or a buoy, a complete standstill of the carrier system is virtually impossible due to the generally prevailing sea state. For high masts resting the carrier platform due to the wind is also not always possible. Previous methods with support data of a navigation platform fail in part due to the insufficient performance of the navigation platform used. Higher-quality navigation platforms are often out of the question for cost reasons. In addition, after an azimuthal rotation, the drift is again detuned by the latitude-dependent influence of the Earth's rotation.

In optronic vision systems, replacement of gyro stabilization with digital image stabilization is impractical because it results in lower stabilization quality and reduced ranges, which is not the case in most systems is acceptable. In addition, the dynamic range (due to the amplitude of the noise) is smaller in this case. Moreover, when using digital image stabilization and mechanically coupled vision or action systems, the system is not suitable for direction finding and target applications. By processing the images also adds a time delay of the displayed image, which is often intolerable.

The publication "Visual Gyroscope: Integration of Visual Information with Gyroscope for Attitude Measurement of Mobile Platform" by Deokhwa Hong et al., Published at the IEEE International Conference on Control, Automation and Systems 2008 (ICCAS), deals with a method of sensor fusion position sensors and imaging sensors for use in a remote-controlled robot. The fusion of the data is used for the electrical calibration of the position sensor during runtime.

The US 8,749,648 B1 relates to a method and / or an architecture for digital video coding, in particular with regard to the compensation of camera movements.

The US 8 151 640 B1 relates generally to on-chip navigation systems, and more particularly to robust navigation systems based on MEMS technology, wherein sensor errors are correctable due to changes in environmental conditions.

The GB 2 481 027 A relates to an image processing apparatus and method, for example for processing image data generated by imaging devices that move during recording.

The US Pat. No. 5,995,141 describes an image pickup device that is capable of outputting digital image data in particular, wherein means for detecting the movement of the device are provided.

The US 2014/0 320 661 A1 refers to an indoor recording system. It is envisaged that with a handheld device equipped with a camera, videos will be made of rooms whose frames will be provided with spatial indices, and doors will also be marked and room-to-room transitions recorded through the doors.

Finally, the concerns US 2012/0 229 385 A1 Handheld devices with integrated gyroscopes. More particularly, it relates to methods for mitigating gyroscope drift errors and hand shakes in such devices.

Proceeding from this, the present invention has the object to provide a support system of the type mentioned, which avoids the disadvantages of the prior art, in particular in which the drift of an existing position sensor in the dynamic operation of the carrier system can be determined safely and possibly compensated.

• – eine lagestabilisierte Komponente;
• – einen bildgebenden Sensor, welcher dazu eingerichtet ist, fortlaufend Bildsignale eines Umgebungsbereichs des Trägersystems zu erfassen;
• – einen, insbesondere inertialen Lagesensor;
• – Stabilisierungsmittel zur fortlaufenden Stabilisierung der Lage und/oder der Ausrichtung der Komponente und des bildgebenden Sensors oder zumindest dessen Sichtlinie in Abhängigkeit von Messsignalen des Lagesensors; und
• – Bildverarbeitungsmittel, welche dazu eingerichtet sind, automatisch eine vorhandene Drift des Lagesensors aus den von dem bildgebenden Sensor erfassten Bildsignalen zu bestimmen, wobei
• – das Trägersystem dazu eingerichtet ist, automatisch die von den Bildverarbeitungsmitteln bestimmte vorhandene Drift des Lagesensors durch die Stabilisierungsmittel, wenigstens annähernd oder vollständig auszuregeln und/oder zu kompensieren.

According to the invention, this object is achieved by a carrier system, comprising at least:

• A position stabilized component;
• An imaging sensor configured to continuously acquire image signals of a surrounding area of the carrier system;
• - One, in particular inertial position sensor;
• - stabilizing means for continuously stabilizing the position and / or the orientation of the component and the imaging sensor or at least the line of sight in response to measurement signals of the position sensor; and
• - Image processing means which are adapted to automatically determine an existing drift of the position sensor from the image signals detected by the imaging sensor, wherein
• - The support system is adapted to automatically compensate for the determined by the image processing means existing drift of the position sensor by the stabilizing means, at least approximately or completely and / or compensate.

The measures according to the invention make it possible to realize automatic drift compensation or drift compensation during operation or during travel or movement of the carrier system or the associated carrier (eg a vehicle). This is preferable to a drift compensation at standstill of the carrier system, as this significantly improves the general use. A standstill of the platform reference surface or the carrier is thus advantageously not required. The drift compensation can take place in dynamic operation, that is to say with movement of the platform reference surface (eg vehicle movement). The drift compensation can automatically control the latitude-dependent influence of the Earth's rotation on the drift in case of a rotation. There is no external high-quality reference gyroscope system, such as a navigation system or the like required. Thus, a dynamic compensation of the drift of a stabilized platform based on scene data is created. The scene data is taken from the imaging sensor whose line of sight is inertially stabilized by the stabilizing system. The imaging sensor may be a visual sensor (camera), a thermal sensor (thermal imaging device or the like), a radar sensor (radar scene) or another passive or active imaging sensor in the electromagnetic spectrum. By The automatic drift compensation according to the invention can generally be used for gyroscopes whose drift property has a low stability, without leaving the considered area gradually. This can save considerable costs.

• – die lagestabilisierte Komponente wenigstens einen bildgebenden Sensor oder ein Element, welches die Sichtlinie des wenigstens einen bildgebenden Sensors stabilisiert, aufweist, wobei
• – eine Drift des Lagesensors fortlaufend bestimmt wird, indem der wenigstens eine bildgebende Sensor oder zumindest dessen Sichtlinie in Abhängigkeit von den Messsignalen des Lagesensors bezüglich der Lage und/oder der Ausrichtung stabilisiert wird, wobei in Bildsignalen des wenigstens einen bildgebenden Sensors wenigstens eine globale Bewegung der von dem wenigstens einen bildgebenden Sensor aufgenommenen Szene innerhalb eines vorgebbaren zeitlichen Abstands erfasst wird, aus welcher die Drift des Lagesensors bestimmt wird, wonach
• – bei Vorhandensein der Drift des Lagesensors diese unter Verwendung der Stabilisierungsmittel wenigstens annähernd ausgeregelt und/oder kompensiert wird.

Claim 13 discloses a method for the continuous stabilization of the position and / or the alignment of a component by means of stabilizing means, based on measuring signals obtained by a position sensor, wherein:

• The position-stabilized component comprises at least one imaging sensor or element which stabilizes the line of sight of the at least one imaging sensor, wherein
• A drift of the position sensor is continuously determined by stabilizing the at least one imaging sensor or at least its line of sight as a function of the measurement signals of the position sensor with respect to the position and / or orientation, wherein in image signals of the at least one imaging sensor at least one global movement of detected by the at least one imaging sensor scene within a predetermined time interval, from which the drift of the position sensor is determined, after which
• - In the presence of the drift of the position sensor, it is at least approximately corrected and / or compensated using the stabilizing means.

• – wenigstens ein bildgebender Sensor oder zumindest dessen Sichtlinie in Abhängigkeit von Messsignalen des Lagesensors bezüglich der Lage und/oder der Ausrichtung stabilisiert wird, und wobei
• – in Bildsignalen des wenigstens einen bildgebenden Sensors wenigstens eine globale Bewegung der von dem wenigstens einen bildgebenden Sensor aufgenommenen Szene innerhalb eines vorgebbaren zeitlichen Abstands erfasst wird, aus welcher die Drift des Lagesensors bestimmt wird.

Furthermore, a method may be provided, in particular for the continuous automatic determination of a drift of a position sensor, in particular in dynamic operation, wherein:

• - At least one imaging sensor or at least its line of sight in response to measurement signals of the position sensor with respect to the position and / or orientation is stabilized, and wherein
• In image signals of the at least one imaging sensor, at least one global movement of the scene recorded by the at least one imaging sensor is detected within a predefinable time interval, from which the drift of the position sensor is determined.

It is also possible to provide a method for, in particular, continuous automatic stabilization of the position and / or orientation of a component, in particular during dynamic operation, by means of stabilization means based on measurement signals obtained by a position sensor, wherein a drift of the position sensor is determined by the method according to the invention a drift of a position sensor is determined continuously, and then in the presence of the drift of the position sensor, this is at least approximately or completely compensated and / or compensated, in particular using the stabilizing means.

The method according to the invention for the continuous stabilization of the position of a component can advantageously also be used as an optional accessory or add-on for new installations, but also for retrofitting existing installations.

It is advantageous if the image processing means are adapted to determine the existing drift of the position sensor and / or in dependence on a global movement of the scene recorded by the image sensor, in particular within a predefinable or variable time interval.

The scene data of the imaging sensor can thus be analyzed with image processing on scene movements. Based on the image content, a global movement is detected for a long time, which is then used for automatic drift compensation. The time interval can be fixed or variable determined.

The carrier system can be set up to convert the global movement of the scene taken by the imaging sensor into an angular movement of the imaging sensor.

The global motion determined from the scene can be converted to an angular movement of the camera by means of the field of view resolution.

A drift control unit may be present in the carrier system which is set up to form a drift compensation signal from the global movement of the scene recorded by the imaging sensor or from the angular movement of the imaging sensor.

The determined global movement of the scene or the angular movement of the camera can be fed to a drift control unit which forms a compensation value with which the drift of the position sensor can be eliminated.

The carrier system may be configured to at least approximately or completely compensate for and / or compensate for the drift of the position sensor contained in the measurement signals of the position sensor by means of the drift compensation signal of the drift controller, in particular before the measurement signals of the position sensor are supplied to the stabilizing means.

To allow sufficient calming of the component or the line of sight of the component reach, the self-drift contained in the output signal of the position sensor can be compensated before the stabilization controller.

The drift control unit may be configured to track the drift compensation signal, in particular with a large time constant.

The drift controller can thus control the scene movement to zero by tracking the drift compensation signal, in particular with a large time constant. The stabilizing means can compensate for movements of the carrier system that change rapidly over time, while the drift controller merely adjusts the drift movements, which change with time delay.

Advantageously, the image processing means may be arranged to determine at least one static area in an image acquired by the imaging sensor for determining the global movement of the scene captured by the image sensor, which is subsequently tracked by means of object tracking or object tracking.

Here, a detected static area in the scene can be passed to an object tracking. Methods for object tracking are well known in the art. This object tracking can then track the position of a manually defined or previously recognized and automatically learned static area in the scene and pass the detected position changes, preferably temporally low-pass filtered, to the drift control unit for compensation. Thus, the global motion and thus the existing drift of the position sensor can be determined by simple means.

The image processing means may be arranged to determine at least two images acquired by the imaging sensor at a time interval, in particular from 0.01 second to 1 hour, preferably from 1 second to 60 seconds, for determining the global movement of the scene taken by the imaging sensor use or compare.

The computation of the global movement or the global drift can be approximately with one in the EP 1 441 316 A2 disclosed methods for determining a sensor own movement done. In the present case, a more distant consideration can be used. For this purpose, at least two images of the imaging sensor can be used at a time interval of 0.01 second to 1 hour, preferably from 1 second to 60 seconds. The at least two images can then be low-pass filtered and converted into the frequency domain by means of a fast Fourier transformation (FFT). There they can be folded, which corresponds to a correlation in the position space and the result can be transformed back into the space by means of a reverse FFT. In the resulting result image, the results of all correlations are given as gray values. The position of the brightest gray value in the result image accordingly corresponds to the displacement of the second image with respect to the first image of the imaging sensor and thus the drift of the stabilization system or of the position sensor in the period between the two images. The global movement of the scene picked up by the imaging sensor or the drift vector can be converted into an angular movement of the imaging sensor or into an angle value on the basis of the current field of view and supplied to the drift controller and thus corrected.

• – wenigstens zwei von dem bildgebenden Sensor erfasste Bilder in einem zeitlichen Abstand, insbesondere von 0,01 Sekunden bis 1 Stunde, vorzugsweise von 1 Sekunde bis 60 Sekunden, verwendet und/oder miteinander verglichen werden; und/oder
• – wenigstens ein statischer Bereich in einem von dem bildgebenden Sensor erfassten Bild bestimmt werden, welcher anschließend mittels einer Objektverfolgung verfolgt wird. Es stehen daher zwei alternative Vorgehensweisen zur Verfügung, die auch miteinander kombinierbar sind.

Thus, to determine the global motion of the scene captured by the imaging sensor:

• At least two images acquired by the imaging sensor are used and / or compared with one another at a time interval, in particular from 0.01 second to 1 hour, preferably from 1 second to 60 seconds; and or
• - At least one static area are determined in an image captured by the imaging sensor, which is subsequently tracked by means of an object tracking. There are therefore two alternative approaches available, which can also be combined with each other.

From the global motion of the scene taken by the imaging sensor or from the angular motion of the imaging sensor, a drift compensation signal may be formed. The drift of the position sensor contained in the measurement signals of the position sensor can be at least approximately or completely compensated and / or compensated by means of the drift compensation signal before the measurement signals of the position sensor are supplied to the stabilizing means. The drift compensation signal can be tracked, in particular with a large time constant.

It is very advantageous if the determined global movement of the scene recorded by the imaging sensor, in particular using a difference image, is checked for plausibility.

Extreme movements in the scene may cause miscalculations of the displacement vector. It is therefore advantageous to detect such miscalculations and then not to stabilize or compensate for the drift use. This can be z. B. by means of a locally tolerant subtraction in a so-called Neuner neighborhood of both images with a detection threshold under consideration of the determined displacement vector. In digital image processing, a neighborhood means a small, defined image region around a pixel, each pixel of an image having four, horizontal and vertical, neighbors characterized by having one pixel edge in common with the pixel. Furthermore, each pixel of an image also has four diagonal neighbors, which share only one corner with the pixel. Sonach can z. B. from a foursome neighborhood or a neighborhood of eight be spoken. The Neuner neighborhood used in the present case is a figure-of-eight neighborhood that has been extended by the middle or central pixel. Pixels arranged at vertices or edges of an image may correspondingly have fewer neighbors. If calculated correctly and with little movement, there are hardly any marks in a difference image created in this way. If a large part of the difference image is marked as a difference, the calculation has failed and the result should not be used, and a new calculation should be made. In local areas with differences, a movement took place in the scene. From an adjustable limit, z. For example, between about 5% and about 50% of the proportion of this local motion in the image, either this calculation can no longer be used or the calculation must be done again masking out these areas. Since the drift compensation takes place at longer intervals and thus is far from subject to video real-time requirements, such iterative or repeated calculations can easily be carried out in the event of errors.

• – Antriebsmittel, um eine, insbesondere definierte Bewegung der lagestabilisierten Komponente durchzuführen; und
• – eine Stabilisierungsreglereinheit, welche mit den Antriebsmitteln und dem Lagesensor kommunikationsverbunden ist, welche die Messsignale des Lagesensors als Eingangssignale erhält und welche dazu eingerichtet ist, um eine in den Messsignalen des Lagesensors vorhandene inertiale Drehbewegung zu Null zu regeln, indem sie die Antriebsmittel derart ansteuert, dass die lagestabilisierte Komponente und insbesondere der Lagesensor nachgeführt werden.

In one embodiment of the invention, the stabilizing agents may comprise:

• - Drive means to perform a, in particular defined movement of the position-stabilized component; and
• A stabilization control unit, which is connected in communication with the drive means and the position sensor, which receives the measurement signals of the position sensor as input signals and which is adapted to control an inertial rotational movement present in the measurement signals of the position sensor to zero, by controlling the drive means in such a way, that the position-stabilized component and in particular the position sensor are tracked.

By this measure, the movement of the carrier system is compensated and the component or its line of sight stabilized.

The, in particular, inertial position sensor can be embodied as a rotational position sensor (eg gyroscope sensor, mechanical gyro or the like) or as a rotation rate sensor (eg gyrometer or the like). There are position sensors of any or different technologies, eg. Mechanical inertial gyros, fiber optic gyroscopes, laser gyros or advanced MEMS gyroscopes / gyros.

The position-stabilized component may comprise the at least one imaging sensor or an element that stabilizes the line of sight of the imaging sensor.

The position stabilized component may be an optronic vision system.

During a manual adjustment of the optronic vision system (change of line of sight / LOS), the drift control unit or the drift compensation can be stopped to prevent mismatching. After completing the straightening process, the newly selected line of sight and the scene to be captured are used as reference.

Advantageous embodiments and developments of the invention will become apparent from the dependent claims. The following is an exemplary embodiment of the invention described in principle with reference to the drawing.

Show it:

1 a schematic representation of the active principle of a carrier system according to the invention;

2 a schematic representation to illustrate a global image movement or a drift in an image;

3 a schematic representation illustrating a small local moving area; and

4 a schematic representation of a carrier system according to the invention.

In the figures, functionally identical elements are provided with the same reference numerals.

In 1 is the principle of action of the automatic drift compensation according to the invention illustrated by an axis. In the process, a global movement over a longer time is detected on the basis of the image content, and this movement is used as additional compensation. 1 shows a carrier system 1 , which by means of a fastening device 10a (eg, a mounting flange or the like) a, in particular mobile carrier 10b (For example, a vehicle) is arranged. In other embodiments, not shown, the carrier system 1 also be part of a, in particular mobile carrier or a particular mobile base. The carrier system 1 has as a position-stabilized component an optronic vision system 2 with a camera (eg in the visual field) as an imaging sensor 2a which is adapted to continuously image signals of a surrounding area of the carrier system 1 capture. In other embodiments, the imaging sensor may also be designed as a thermal imaging device. Furthermore, the optronic vision system 2 also have several, in particular different imaging sensors. A line of sight LOS of the imaging sensor 2a is in 1 indicated by a dashed arrow. The carrier system 1 also has a rotation rate sensor 3 trained position sensor on. In further embodiments, another position sensor, for. B. a rotary position sensor are used. In the present embodiment, the optronic vision system 2 with the imaging sensor 2a and the rotation rate sensor 3 on a stabilized platform 4 arranged. In further embodiments, not shown, could with the necessary changes to a stabilized platform 4 or the like can be dispensed with. In this case, the carrier system could serve for stabilization. The rotation rate sensor 3 can, as in 1 indicated, have a drift or a self-drift. The carrier system 1 further includes stabilizing agents 5 for the continuous stabilization of the position of the optronic vision system 2 and the imaging sensor 2a or at least its line of sight LOS as a function of measuring signals m_s of the rotation rate sensor 3 (in rad / s), which can have an inertial rotation rate, in particular with a drift. The carrier system 1 further comprises image processing means 6 , which are adapted to automatically an existing drift of the rotation rate sensor 3 from the of the imaging sensor 2a recorded and to the image processing means 6 to determine the transmitted image signals v_s. The carrier system 1 is set to automatically the image processing means 6 certain existing drift of the rotation rate sensor 3 through the stabilizers 5 at least approximately or completely correct and / or compensate.

The stabilizers 5 comprise drive means designed as a motor, preferably an electric motor 5a to move the stabilized platform 4 or the position-stabilized component or the optronic vision system 2 and a stabilizer control unit 5b , which with the drive means 5a and the rotation rate sensor 3 is communicatively connected, which the measurement signals m_s the rotation rate sensor 3 receives as input signals, and which is adapted to one in the measurement signals m_s the rotation rate sensor 3 to regulate existing inertial rotational motion to zero by using the drive means 5a in such a way that the optronic vision system 2 and the rotation rate sensor 3 or the stabilized platform 4 on which the optronic vision system 2 and the rotation rate sensor 3 are arranged, is tracked.

The image processing means 6 received as input signal from the imaging sensor 2a captured image signals v_s. The image processing means 6 are adapted to the existing drift of the rotation rate sensor 3 from or in response to a global motion of the imaging sensor 2a determined scene within a predeterminable or variable time interval. The image processing means 6 provide as output a signal indicating the global motion of the imaging sensor 2a recorded scene (in pixels / s) and which in the 1 is provided with the reference b_s. The carrier system 1 is configured to detect the detected global motion b_s of the imaging sensor 2a recorded scene, preferably by means of a field of view resolution A, in an angular movement of the imaging sensor 2a to convert (in rad / s). The angular movement of the imaging sensor 2a characterizing signal is in 1 is provided with the reference symbol w_s and is a drift control unit 7 again supplied as an input signal. The drift controller unit 7 is adapted to from the signal b_s of the global motion of the imaging sensor 2a recorded scene and / or from the signal w_s the angular movement of the imaging sensor 2a to form a drift compensation signal d_s (in rad / s).

How out 1 can be seen, the drive means 5a the stabilized platform 4 or the optronic vision system 2 and the rotation rate sensor 3 stabilize in an indicated by the double arrow P1 adjustment direction or axis. However, the principle can equally be used for two- and three-axis stabilization. By tracking the optronic vision system 2 becomes the line of sight LOS of the optronic vision system 2 or the imaging sensor 2a stabilized.

The in the measurement signals m_s of the rotation rate sensor 3 included drift of the rotation rate sensor 3 is determined by means of the drift compensation signal d_s of the drift control unit 7 adjusted and / or compensated before the measurement signals m_s the rotation rate sensor 3 the stabilizing agents 5 be supplied. For this purpose, the drift compensation signal d_s is suitably applied to the measurement signals m_s of the rotation rate sensor 3 after which these drift-adjusted measuring signals mb_s of the rotation rate sensor 3 the stabilization controller unit 5b the stabilizer 5 be supplied as an input signal. The drift-adjusted measuring signals mb_s of the rotation rate sensor 3 are thus the drift of the rotation rate sensor 3 adjusted. The drift controller unit 7 is adapted to track the drift compensation signal d_s, in particular with a large time constant.

In 2 For example, a global image movement or a drift vector in an image captured by an imaging sensor is illustrated by arrows P2. In contrast, in 3 a small locally moving area L indicated in a differential image.

The image processing means 6 may be configured to determine the global motion b_s of the imaging sensor 2a recorded scene at least two of the imaging sensor 2a captured images at a time interval, in particular from 0.01 seconds to 1 hour, preferably from 1 second to 60 seconds to use.

The calculation of the global motion or the global drift can be done with a in the EP 1 441 316 A2 described method for determining a sensor own movement done. In the present case, a more distant consideration can be used. For this purpose, at least two images of the imaging sensor 2a be used at a time interval of 0.01 second to 1 hour, preferably from 1 second to 60 seconds. The at least two images can then be low-pass filtered and converted into the frequency domain by means of a fast Fourier transformation (FFT). There they can be folded, which corresponds to a correlation in the position space and the result can be transformed back into the space by means of a reverse FFT. In the resulting result image, the results of all correlations are given as gray values. The position of the brightest gray level in the result image accordingly corresponds to the displacement of the second image with respect to the first image of the imaging sensor 2a and thus the drift of the stabilization system or the yaw rate sensor 3 in the period between the two shots (see 2 ).

The determined global motion b_s of the imaging sensor 2a recorded scene can be checked for plausibility, in particular using a difference image.

Extreme movements in the scene may cause miscalculations of the drift vector. It is therefore advantageous to detect such miscalculations and not to use for stabilization or to compensate for the drift. This can be z. B. by means of a locally tolerant subtraction in a so-called Neuner neighborhood of both images with a detection threshold taking into account the determined drift vector. If calculated correctly and with little movement, there are hardly any marks in a difference image created in this way. If a large part of the difference image is marked as a difference, the calculation has failed and the result should therefore not be used, whereby a new calculation should take place. In local areas with differences, a movement took place in the scene (see 3 ). From an adjustable limit, z. For example, between about 5% and about 50% of the proportion of this local motion in the image, either this calculation can no longer be used or the calculation must be done again masking out these areas. Since the drift compensation takes place at longer intervals and thus is far from subject to video real-time requirements, such iterative or repeated calculations can easily be carried out in the event of errors.

Alternatively or additionally, the image processing means 6 be configured to determine the global motion b_s of the imaging sensor 2a recorded scene at least one static area in one of the imaging sensor 2a captured image, which is subsequently tracked by means of an object tracking.

In this case, a recognized static area in the scene can be followed by an object tracking (tracking) of the image processing means 6 be handed over. Methods for object tracking are well known in the art. This object tracking can then track the position of a previously recognized and automatically taught-in static area in the scene and pass on the position changes detected thereby, preferably with low-pass filtering in terms of time, to the drift control unit for compensation. In this way, the global motion and thus the existing drift of the rotation rate sensor 3 be determined by simple means.

• – der bildgebende Sensor 2a oder zumindest dessen Sichtlinie LOS in Abhängigkeit von den Messsignalen m_s des Drehratensensors 3 bezüglich der Lage und/oder der Ausrichtung stabilisiert wird, und wobei
• – in den Bildsignalen v_s des bildgebenden Sensors 2a wenigstens eine globale Bewegung b_s der von dem bildgebenden Sensor 2a aufgenommenen Szene innerhalb eines vorgebbaren zeitlichen Abstands erfasst wird, aus welcher die Drift des Drehratensensors 3 bestimmt wird.

Thus, a method for determining the drift of the rotation rate sensor 3 indicated, wherein:

• - the imaging sensor 2a or at least its line of sight LOS in dependence on the measurement signals m_s of the rotation rate sensor 3 is stabilized with respect to the position and / or orientation, and wherein
• In the image signals v_s of the imaging sensor 2a at least one global movement b_s that of the imaging sensor 2a recorded scene within a predetermined time interval, from which the drift of the rotation rate sensor 3 is determined.

Furthermore, a method for continuously stabilizing the position and / or the orientation of the optronic vision system 2 by means of the stabilizing agent 5 based on the rotation rate sensor 3 received measurement signals m_s provided, wherein the drift of the rotation rate sensor 3 by means of the above-mentioned method for determining the drift of the rotation rate sensor 3 is continuously determined, and then in the presence of drift, these, in particular using the stabilizing agent 5 , at least approximately or completely compensated and / or compensated.

4 shows an embodiment of a movable carrier system according to the invention 1 with an optronic vision system stabilized in two axes EL (elevation) and AZ (azimuth), designed as a sensor head 2 , The fastening device designed as a fastening flange 10a connects the optronic vision system 2 or the carrier system 1 with the carrier 10b , An adjustability of the optronic vision system 2 as a position-stabilized component with respect to the axes EL and AZ is indicated by double arrows P3a and P4a. This can be indicated by double arrows P3b and P4b movements of the carrier 10b with respect to the axes EL and AZ are compensated by the position stabilization accordingly. Translational directions are symbolized by the double arrows P5. The optronic vision system 2 has an imaging sensor designed as a camera 2a and another imaging device configured as a thermal imaging device 2 B on. A rotation rate sensor 3 , which supplies measurement signals in both axes EL, AZ, is in the optronic vision system 2 integrated (indicated by dashed lines). Furthermore, first drive means 5a.1 for adjusting the optronic vision system 2 along the axis EL and second drive means 5a.2 for adjusting the optronic vision system 2 provided along the axis AZ. Of course, the optronic vision system 2 or the carrier system 1 according to 4 also the components 5b . 6 and 7 have (indicated by dashed lines). In principle, both imaging sensors can be used to determine the drift 2a and 2 B be used both individually and in combination.

LIST OF REFERENCE NUMBERS

1

carrier system

2

optronic vision system

2a, 2b

Imaging sensors

3

Yaw rate sensor

4

stabilized platform

5

stabilizer

5a, 5a.1, 5a.2

drive means

5b

Stabilization regulator unit

6

Image processing means

7

Drift regulator unit

10a

fastening device

10b

carrier

COME ON

Line-of-Sight / line of sight

A

Sehfeldauflösung

L

locally moved area

EL

Axis elevation

AZ

Axis azimuth

m_s

Measuring signals of the position sensor

mb_s

drift-adjusted measuring signals of the position sensor

V_S

Image signals of the imaging sensor

B_s

Signal regarding the global movement of the scene

w_s

Signal relating to the angular movement of the imaging sensor

d_s

Drift compensation signal

P1, P2, P3a, P3b, P4a, P4b, P5

 Arrows / double arrows

Claims (21)

Carrier system ( 1 ), comprising at least: - a position-stabilized component ( 2 ); An imaging sensor ( 2a . 2 B ), which is arranged to continuously display image signals of a surrounding area of the carrier system ( 1 ) capture; A position sensor ( 3 ); Stabilizing agent ( 5 ) for continuously stabilizing the position and / or orientation of the component ( 2 ) and the imaging sensor ( 2a . 2 B ) or at least its line of sight (LOS) as a function of measuring signals (m_s) of the position sensor ( 3 ); and image processing means ( 6 ), which are adapted to automatically detect an existing drift of the position sensor ( 3 ) from the imaging sensor ( 2a . 2 B ) detected image signals (v_s), wherein - the carrier system ( 1 ) is arranged to automatically read the image processing means ( 6 ) certain existing drift of the position sensor ( 3 ) by the stabilizing agents ( 5 ) at least approximately correct and / or compensate. Carrier system ( 1 ) according to claim 1, wherein the image processing means ( 6 ) are adapted to the existing drift of the position sensor ( 3 ) from a global movement (b_s) of the imaging sensor ( 2a . 2 B ) within a predefinable or variable time interval. Carrier system ( 1 ) according to claim 2, which is adapted to control the global movement (b_s) of the imaging sensor ( 2a . 2 B ) recorded scene in an angular movement (w_s) of the imaging sensor ( 2a . 2 B ) to convert. Carrier system ( 1 ) according to claim 2 or 3, wherein a drift control unit ( 7 ), which is adapted from the global motion (b_s) of the imaging sensor ( 2a . 2 B ) or from the angular movement (w_s) of the imaging sensor ( 2a . 2 B ) to form a drift compensation signal (d_s). Carrier system ( 1 ) according to claim 4, which is set up in the measuring signals (m_s) of the position sensor ( 3 ) contained drift of the position sensor ( 3 ) by means of the drift compensation signal (d_s) of the drift control unit ( 7 ) and / or compensate before the measuring signals (m_s) of the position sensor ( 3 ) the stabilizing agents ( 5 ). Carrier system ( 1 ) according to claim 4 or 5, wherein the drift control unit ( 7 ) is adapted to track the drift compensation signal (d_s), in particular with a large time constant. Carrier system ( 1 ) according to one of claims 2 to 6, wherein the image processing means ( 6 ) are arranged to determine the global movement (b_s) of the imaging sensor ( 2a . 2 B ) recorded at least one static area in one of the imaging sensor ( 2a . 2 B ), which is subsequently tracked by means of object tracking. Carrier system ( 1 ) according to one of claims 2 to 7, wherein the image processing means ( 6 ) are arranged to determine the global movement (b_s) of the imaging sensor ( 2a . 2 B ) recorded scene at least two of the imaging sensor ( 2a . 2 B ) to be used at a time interval, in particular from 0.01 seconds to 1 hour, preferably from 1 second to 60 seconds. Carrier system ( 1 ) according to any one of claims 1 to 8, wherein the stabilizing agents ( 5 ) comprise: - drive means ( 5a . 5a.1 . 5a.2 ) to detect a movement of the position-stabilized component ( 2 ) perform; and a stabilization control unit ( 5b ), which with the drive means ( 5a . 5a.1 . 5a.2 ) and the position sensor ( 3 ) which is connected to the measurement signals (m_s) of the position sensor ( 3 receives as inputs and which is adapted to one in the measurement signals (m_s) of the position sensor ( 3 ) existing inertial rotational movement to zero by the drive means ( 5a . 5a.1 . 5a.2 ) such that the position-stabilized component ( 2 ) and the position sensor ( 3 ) are tracked. Carrier system ( 1 ) according to one of claims 1 to 9, wherein the position sensor as a rotational position sensor or yaw rate sensor ( 3 ) is executed. Carrier system ( 1 ) according to one of claims 1 to 10, wherein the position-stabilized component ( 2 ) the imaging sensor ( 2a . 2 B ) or an element which the line of sight of the imaging sensor ( 2a . 2 B ) stabilized. Carrier system ( 1 ) according to one of claims 1 to 11, wherein the position-stabilized component is an optronic vision system ( 2 ). Method for the continuous stabilization of the position and / or the orientation of a component ( 2 ) by means of stabilizing agents ( 5 ) based on a position sensor ( 3 ) received measurement signals (m_s), wherein: - the position-stabilized component ( 2 ) at least one imaging sensor ( 2a . 2 B ) or an element which the line of sight (LOS) of the at least one imaging sensor ( 2a . 2 B ), wherein - a drift of the position sensor ( 3 ) is continuously determined by the at least one imaging sensor ( 2a . 2 B ) or at least its line of sight (LOS) as a function of the measuring signals (m_s) of the position sensor ( 3 ) is stabilized with respect to the position and / or the orientation, wherein in image signals (v_s) of the at least one imaging sensor ( 2a . 2 B ) at least one global movement (b_s) of the at least one imaging sensor ( 2a ) recorded scene within a predetermined time interval, from which the drift of the position sensor ( 3 ), after which - in the presence of the drift of the position sensor ( 3 ) using the stabilizing agent ( 5 ) is at least approximately corrected and / or compensated. The method of claim 13, wherein the global motion (b_s) of the imaging sensor ( 2a . 2 B ) recorded scene in an angular movement (w_s) of the imaging sensor ( 2a . 2 B ) is converted. Method according to Claim 13 or 14, in which the global motion (b_s) is determined by the image generated by the imaging sensor (b_s). 2a . 2 B ): at least two of the imaging sensor ( 2a . 2 B ) are used at a time interval, in particular from 0.01 second to 1 hour, preferably from 1 second to 60 seconds; and or At least one static region in one of the imaging sensors ( 2a . 2 B ), which is subsequently tracked by means of object tracking. Method according to claim 13, 14 or 15, wherein the determined global movement (b_s) is determined by the imaging sensor ( 2a . 2 B ) recorded scene, in particular using a difference image, is checked for plausibility. Method according to one of claims 13 to 16, wherein the global motion (b_s) of the imaging sensor ( 2a . 2 B ) or from the angular movement (w_s) of the imaging sensor ( 2a . 2 B ) a drift compensation signal (d_s) is formed. A method according to claim 17, wherein in the measuring signals (m_s) of the position sensor ( 3 ) contained drift of the position sensor ( 3 ) is compensated and / or compensated by means of the drift compensation signal (d_s) before the measurement signals (m_s) of the position sensor ( 3 ) the stabilizing agents ( 5 ).  The method of claim 17 or 18, wherein the drift compensation signal (d_s), in particular with a large time constant, tracked. Method according to one of claims 13 to 19, wherein as a position sensor, a rotational position sensor or a rotation rate sensor ( 3 ) is used. Method according to one of claims 13 to 20, wherein as a position-stabilized component an optronic vision system ( 2 ) is used.

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