Test setup and method for stimulating an infrared camera-based environment detection system

Abstract

Test arrangement (1) for stimulating an infrared camera-based environment detection system for test purposes, comprising a holding device (2a) in which an infrared camera (2) can be fixed as a test object, an infrared light source (4), a computer-controlled imaging device (3), and wherein the infrared light source, the imaging device and the recording device are arranged such that an optical path leads from the light source through the computer-controlled imaging device to the test object.

Description

[0001] The invention relates to a test bench for stimulating an environment detection system operating with infrared cameras, as well as a method for stimulating an infrared camera-based environment detection system.

[0002] Vehicles with advanced driver assistance systems (ADAS), e.g., for autonomous and semi-autonomous driving, can use various sensors to detect the environment, such as cameras, radar sensors, ultrasonic sensors, and / or lidar sensors. A camera can be configured, for example, as a near-infrared camera.

[0003] One variant of driver assistance systems specializes in driver monitoring, also known as "driver monitoring systems." High-resolution infrared cameras optimized for the near-infrared range are increasingly being used for this purpose. Driver monitoring systems are safety-critical systems and, as such, require thorough evaluation to best prevent malfunctions during use. This evaluation of the sensor technology is preferably carried out before a vehicle is tested on the road. Road tests are expensive, complex, and risky.

[0004] Within the framework of hardware-in-the-loop testing, it has become established practice to integrate the ECU under test into a simulated context as untouched as possible, i.e., to operate it in a closed control loop with real-time environmental and vehicle simulation. For active environmental sensors such as radar or lidar sensors, target simulators are used. These capture the scanning signal from the sensor under test and return a simulated or manipulated echo signal. For passive sensors such as cameras, so-called camera boxes are known for this purpose. These can play simulated scenes to stimulate the sensor. The advantage here is that the real sensor is used as a whole, and no interfaces need to be opened or test bench modes activated.

[0005] If such a target simulator is not available, the sensor data can be simulated at the electrical signal level and fed into the sensor's signal processing chain behind the actual sensor front end. The disadvantage of this approach is that the entire processing chain cannot be tested.

[0006] While solutions are known for cameras in the visible range, stimulation at the optical level is not possible for cameras in the infrared or near-infrared range, as devices for generating high-resolution near-infrared images are currently unknown. The object of the invention is to further develop the state of the art.

[0007] Against this background, a novel test arrangement and a method for stimulating an infrared camera-based environment detection system according to claims 1 and 9 are proposed.

[0008] The test setup comprises a holding device in which an infrared camera can be fixed as the test object, an infrared light source, and a computer-controlled imaging device. The infrared light source, the imaging device, and the recording device are arranged such that an optical path leads from the light source through the computer-controlled imaging device to the test object. This allows the light source to be used in a targeted manner and the emitted light to be channeled to stimulate the test object. Additional imaging elements such as polarizers, lenses, collimators, or similar devices can be provided between the light source and the imaging device, or between the imaging device and the test object. The imaging device is computer-controlled.

[0009] In embodiments, the computer-controlled imaging device is provided by a computer-controlled matrix with matrix elements. At least one matrix element can be controlled such that the optical path through the matrix element is optionally transparent or blocked. Several rows and columns of matrix elements can be provided, which are arranged such that they are illuminated by the light source, and the light can fall onto the test object in the transparent state. This makes it particularly easy to create a device that enables a complex light pattern for testing the infrared camera.

[0010] Against this background, it is advantageous that each matrix element can be activated individually and independently of other matrix elements, so that these activated matrix elements emit light, which is received by the test object. This occurs independently of the actual light source, which could be, for example, an array of infrared LEDs or infrared laser LEDs. Each of the matrix elements then emits exactly one light beam.

[0011] In a further embodiment, the matrix elements have at least a first state in which the optical path is transparent or continuous, and a second state in which the optical path is blocked or not continuous. For this purpose, the matrix elements have darkening elements for mechanical blocking, which are optionally located inside or outside the optical path.

[0012] In a further embodiment, it is provided that the matrix elements have polarization filters which, by rotating the polarization direction, have an optionally permeable or blocking effect and thus enable selective blocking.

[0013] In a further embodiment, the matrix elements comprise mirror elements. These can be selectively adjusted either so that the light from the light source is reflected onto the test object, thus making the optical path transparent, or so that the light from the light source is reflected into a light trap. The latter option blocks the optical path. The mirror elements can be designed, for example, as micromirrors, also known as "digital micromirror devices," or generally as MEMS (micro electromechanical system) mirrors.

[0014] In one variant of the test setup, the infrared light source is provided by an infrared laser. This emits a substantially focused, i.e., approximately parallelized laser beam. Furthermore, the imaging device is provided by a laser deflection device, which selectively images the laser beam onto the infrared camera using a raster method, or blocks it. The laser deflection can be implemented as a galvanometer scanner or using MEMS systems.

[0015] In one embodiment, a computer is installed in the test setup. The computer is configured to transmit control signals to the imaging device or the computer-controlled matrix according to the specifications of a control program executable on the computer in order to selectively activate or deactivate matrix elements. The control signals are transmitted via an operative connection, which is in particular a data interface. The operative connection exists between the computer or the control device and the imaging device or the computer-controlled matrix.

[0016] In a further embodiment, this computer or a second computer executes an environmental simulation from the perspective of the test object, which calculates virtual environmental objects in the field of view of the test object. The computer executing the environmental simulation is also configured to send control signals to the matrix based on the virtual environmental objects, or to issue instructions to the first computer to send control signals to the matrix. This can also be done by a programmable control device. The computer or the programmable control device is configured to activate selected matrix elements according to a control program stored on the computer or the control device so that they become permeable.

[0017] For this purpose, the computer or control device has a data memory.

[0018] The test arrangement according to the invention is thus configured to display one or more virtual environmental objects and provide them for stimulating the infrared camera. A connection can be established between the computer executing the environmental simulation and the test object. In addition to the environmental simulation, a simulation of a test vehicle, the test driver, and the driving dynamics of the test vehicle can also be performed. Using the aforementioned connection, the control loop can be closed, allowing stimulation to occur within the framework of a closed-loop simulation. The reaction of the test object can be recorded, for example, in the form of sensor data and control signals, and used for the next simulation step.

[0019] The invention further relates to a method for stimulating an infrared camera-based environment detection system. The following method steps are provided: arranging a holding device and fixing an infrared camera as a test object in the holding device; arranging an infrared light source and a computer-controlled matrix with matrix elements such that an optical path is selectively permeable or blocked when the matrix elements are controlled; and further providing for arranging the infrared light source, the matrix, and the recording device such that the optical path leads from the light source through at least one matrix element of the computer-controlled matrix to the test object.

[0020] The invention is explained in more detail below with reference to the accompanying figures. The figures and their description show exemplary embodiments of the invention. The figures are schematic and do not allow any conclusions to be drawn about the geometric dimensions of the components or their distances from one another.

[0021] The figures show Fig. 1 A schematic view of an embodiment of the test arrangement according to the invention Fig. 2 A schematic view of a further embodiment of the test arrangement according to the invention Fig. 3 A schematic view of a further embodiment of the test arrangement according to the invention Fig. 4 A schematic view of possible design of the computer-controlled matrix Fig. 5 A schematic view of another possible embodiment of the computer-controlled matrix

[0022] In the Fig. Figure 1 shows an infrared camera arranged as test object 2 in the test setup 1 according to the invention. The test object 2 is not intended to be part of the test setup. This illustration was chosen solely to illustrate the overall system during test operation. To position the test object 2, the test setup 1 further comprises a holding device 2a. This can be designed in a variety of ways, with the exact configuration being adapted to the design of the selected test object 2. In the simplest case, the holding device 2a is a simple plate on which the test object 2 rests. The test setup 1 further comprises an infrared light source 4 and an imaging device 3. The above-mentioned line of sight is achieved when an optical path 6 leads from the infrared light source 4 through the imaging device 3 to the test object 2.The holding device 2a and the other components of the test arrangement 1, imaging device 3 and infrared light source 4, are arranged in such a way that a line of sight exists between the detector of the test object 2 (not shown here) and the imaging device and the light source 4. The imaging device 3 is computer-controlled so that it is at least partially intentionally transparent and partially intentionally opaque to the light from the light source 4.

[0023] In the Fig. Figure 2 shows another embodiment of the test arrangement according to the invention. In addition to the components already shown, this arrangement also includes a computer 5, which has an operative connection 3-5 with the imaging device 3. In the simplest case, the computer 5 is a control device, and the signal connection 3-5 is a data interface. Control signals can be sent to the imaging device via the latter, which control the proportion of the imaging device 3 that should be transparent and the proportion that should be opaque.

[0024] The test arrangement according to the invention also makes it possible to perform a stimulation of the test object in a closed circuit. This embodiment is shown in Fig. 3. Here, there is a further signal connection 2-5 between computer 5 and test object 2. Computer 5 can be designed to simulate the environment of the test object. For this purpose, for example, the environment of a vehicle can be modeled with environmental objects, or a driver who is to be observed by the test object - i.e., an infrared camera. The vehicle in which the test object is normally installed and the driving dynamics can also be modeled. The environmental objects specified by the environmental simulation are now to be observed and recognized by the test object. For this purpose, the simulated situation can be displayed on the imaging device, with the individual pixels being controlled according to the environmental objects specified by the simulation. This makes it possible to check whether the test object shows the expected reaction. For example, automatic braking can occur.The test object's reaction can be sent back to computer 5 via signal connection 2-5 and influence the execution of the simulation. However, it is also possible that no closed loop exists and the test object's reaction is simply logged or read, for example.

[0025] In Fig. Figure 4 shows a possible embodiment of the imaging device 3 according to the invention. In this example, it can be designed as a computer-controlled matrix 3'. A matrix of matrix elements 3'a can be provided, which can be individually controlled and, upon control, can assume the transparent or non-transparent states. Furthermore, it is provided that illumination with an infrared light source 4 is arranged behind the matrix, which illumination here is provided by individual light sources 4a distributed over an area that approximately corresponds to the area of ​​the matrix.

[0026] This is one possible example. Another example is conceivable and is shown in Fig. 5. Here, the matrix 3 is illuminated from the front. The light source 4 can be a laser or a laser LED 4b or even an IR diode 4a (not shown here). It can be provided to collimate or focus the light source using lenses. The matrix elements 3a here are provided by reflective elements such as micromirrors. These can be controlled individually and assume at least two alignment positions. It is advantageous to select one of the positions so that the light from the light source is reflected towards the test object. Another should be selected so that the light is not reflected towards the test object, for example into a light trap. List of reference symbols 1 test setup 2 test object 2a Holding device 3 Imaging device 3' Computer-controlled matrix 3'a Matrix elements 3-5 Signal connection 2-5 Signal connection 4 Infrared light source 4a Infrared diode 4b Infrared laser source 5 computers 6 Optical path

Claims

[1] Test arrangement (1) for stimulating an infrared camera-based environment detection system for test purposes, comprising a holding device (2a) in which an infrared camera (2) can be fixed as a test object, an infrared light source (4), a computer-controlled imaging device (3), and wherein the infrared light source, the imaging device and the recording device are arranged such that an optical path leads from the light source through the computer-controlled imaging device to the test object. [2] Test arrangement (1) according to claim 1, wherein the computer-controlled imaging device is provided by a computer-controlled matrix (3') with matrix elements (3a), wherein at least one matrix element (3a) can be controlled such that the optical path (6) is selectively transparent or blocked by the matrix element. [3] Test arrangement according to claim 2, wherein the matrix elements (3a) have at least a first state in which the optical path is transparent and a second state in which the optical path is blocked, and wherein the matrix elements have, for this purpose, darkening elements for mechanical blocking, which are optionally located in or outside the optical path. [4] Test arrangement according to claim 2, wherein the matrix elements (3a) have at least a first state in which the optical path is transparent and a second state in which the optical path is blocked, and wherein the matrix elements have for this purpose polarization filters which have a selectively transparent or blocking effect by rotating the polarization direction. [5] Test arrangement according to claim 2, wherein the matrix elements (3a) have at least a first state in which the optical path is transparent and a second state in which the optical path is blocked, and wherein the matrix elements have for this purpose mirror elements which selectively cause the continuity of the optical path or a blockage of the optical path deflection into a light trap. [6] Test arrangement according to claim 1, wherein the infrared light source is provided by an infrared laser which emits a substantially collimated laser beam, and the imaging device is provided by a laser deflection which selectively images or blocks the laser beam in a raster process onto the infrared camera. [7] Test arrangement according to one of the preceding claims, which further comprises a computer (5), wherein the computer is arranged to send control signals to the computer-controlled matrix according to the specifications of a control program executable on the computer in order to selectively activate or deactivate matrix elements. [8] Test arrangement according to claim 7, wherein the computer or a second computer executes an environmental simulation from the point of view of the test object, which calculates virtual environmental objects in the field of view of the test object, and is further configured to send control signals to the matrix based on the virtual environmental objects, or to output instructions to the first computer to send control signals to the matrix. [9] Method for stimulating an infrared camera-based environment detection system, the method comprising the following steps: arranging a holding device (2a), and fixing an infrared camera (2) as a test object in the holding device, further arranging an infrared light source (4), a computer-controlled matrix (3) with matrix elements (3a), so that an optical path (6) is optionally permeable or blocked when the matrix elements (3a) are controlled, and further providing for arranging the infrared light source, the matrix and the recording device such that the optical path from the light source leads through at least one matrix element of the computer-controlled matrix to the test object.

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