Optical detection device for monitoring a surveillance area with inspection for functional safety - Patent Application 20070122997

Abstract

A method for controlling an optical detection device (12), a detection device (12) and a vehicle (10) having at least one detection device (12) is described. In the method, at least one light emitting element (40) is activated to transmit at least one optical signal (42). At least one reflected optical signal (60) is received using at least two receiving areas of at least one receiver (52). At least one receiving variable (54) is determined using the at least one received optical signal (42). Functional safety of the detection device (12) is at least intermittently tested. The duration of the transmission of each of the optical signals (42) is limited to a specified transmission time interval. To achieve eye safety of the detection device (12), at least one measurement receiving area is generated using at least one measurement receiving area to characterize the amount of light captured during a measurement time interval. At least one test receiving area is generated using at least one test receiving area to characterize the amount of light captured during a test time interval. The test time interval is greater than the measurement time interval and the test time interval is greater than the transmission time interval. If the test receive quantity characterizes an amount of light that is greater than the amount of light characterized by the measured receive quantity beyond a predetermined tolerance, a fault condition is generated.

Description

[Technical Field]

[0001] The present invention relates to a method for operating an optical detection device arranged to monitor at least a monitoring area, the method comprising: at least one light-emitting element is activated to transmit at least one optical signal; At least one reflected optical signal is received using at least two receiving areas of at least one receiver; determining at least one received variable using the at least one received optical signal; The functional safety of the detection device is checked at least intermittently; Regarding the method.

[0002] The present invention also provides an optical detection device for monitoring at least one monitoring area, comprising: having at least one light emitting element for transmitting an optical signal; having at least two receiving areas for receiving reflected optical signals; at least one means for determining a reception variable from the received optical signal; at least one means for controlling the optical detection device and for processing received variables; having at least one means for checking the functional safety of the detection device, It relates to optical detection devices.

[0003] Furthermore, the present invention provides a vehicle having at least one detection device for monitoring at least one monitoring area, wherein the at least one detection device comprises: at least one light emitting element for transmitting an optical signal; at least two receiving areas for receiving reflected optical signals; at least one means for determining a reception variable from the received optical signal; at least one means for controlling the optical detection device and for processing received variables; At least one means for checking the functional safety of the detection device; The present invention relates to a vehicle having a [Background technology]

[0004] A method for calibrating an optical scanning system is known from DE 102017223618 A1. This method begins with a step in which an optical transmitting unit transmits a laser beam, which is transmitted to a rear region of a housing during a dark phase. In other words, the optical scanning system emits light toward a rear or rear region of the housing that is opaque to the optical beam. In a subsequent step, the laser beam is redirected using a reflector unit arranged in the rear region of the housing. This means that the reflector unit redirects the laser beam so that it is immediately received or captured by an optical receiving unit, i.e., without interacting with objects from the surroundings outside the housing. In a subsequent step, the laser beam redirected or deflected by the reflector unit is received by a receiving unit. In a subsequent step, the orientation of the laser beam is determined, and in a subsequent step, a detector unit of the optical receiving unit is calibrated based on the orientation of the laser beam. As an alternative or in addition to the step in which the detector unit is calibrated, a step can include determining the laser power based on the redirected laser beam. Optionally, separate steps following the step in which the orientation of the laser line is determined may include determining eye safety based on the redirected laser line and monitoring individual laser diodes based on the redirected laser line or functional safety of the optical scanning system.

[0005] The present invention is based on the object of designing a method, a detection device and a vehicle of the above type, with improved functional safety of the detection device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Patent Application Publication No. 102017223618 Summary of the Invention

[0007] The present invention provides the duration of each transmission of the optical signal is limited to a specified transmission time interval to achieve eye safety of the detection device; The eye safety of the detection device by configuring at least one of the receiving areas as a measurement receiving area and at least one of the receiving areas as a test receiving area; by generating at least one measurement reception variable characterizing an amount of light captured using at least one measurement reception area during at least one measurement time interval; by generating at least one test reception variable characterizing an amount of light captured using at least one test reception area during at least one test time interval; at least one test time interval is longer than at least one measurement time interval, and at least one test time interval is longer than the transmission time interval; A fault condition is generated if at least one test receiving variable characterizes an amount of light that is greater outside the specified tolerance variables than the amount of light characterized using at least one measured receiving variable. In this respect, this object of the present method is achieved.

[0008] According to the present invention, eye safety for the detection device is achieved by limiting the transmission of the optical signal. For this purpose, the duration of the transmission of the optical signal is limited to a specified transmission time interval in each case. For optical signals transmitted for the duration of the transmission time interval, the longer the transmission time interval, the greater the amount of light transmitted. Eye safety for the detection device is achieved by limiting the amount of light transmitted for the transmission time interval. The transmission time interval is specified in particular based on the type of optical signal transmitted to ensure eye safety.

[0009] Eye safety of a detection device within the meaning of the present invention is a function and / or property of the detection device that ensures that in particular legally prescribed eye safety limits are observed when operating the detection device. Eye safety is the functional safety of the detection device.

[0010] Advantageously, limiting the duration of the transmission of the optical signal using at least one safety means can be performed in particular by software and / or hardware.

[0011] Advantageously, at least one transmission time interval can be specified such that the transmission of the optical signal is significantly below the eye safety limit, thereby ensuring that the eye safety limit is safely observed.

[0012] The receiving area of ​​the at least one receiver is used to receive reflected optical signals, which may be called echo signals, and convert them into received variables. Advantageously, the receiving area can be used to receive optical signals from at least one monitored area, in particular reflected by objects. The received variables can be used to determine information about the monitored area, in particular object information such as the distance, speed and / or direction of the object relative to the detection device.

[0013] Furthermore, at least one reception variable can be obtained as a basis for testing the eye safety of the detection device. This can include using a reception variable derived from an echo signal coming from at least one monitoring area. Alternatively or additionally, a reception variable from an optical signal reflected within the detection device can be used.

[0014] In particular, a malfunction of at least one safety means may lead to the optical signal still being transmitted after the transmission time interval has expired, which may compromise eye safety.

[0015] To test the eye safety of the detection device, in particular the function of at least one safety measure, the reflected optical signal is received using at least two receiving areas, i.e., at least one measurement receiving area and at least one test receiving area, and converted into a respective reception variable. The reflected optical signal is captured using the at least one measurement receiving area for the duration of at least one measurement time interval. At least one test receiving area is used to capture the optical signal for the duration of at least one test time interval.

[0016] The at least one test time interval is longer than the transmission time interval, and in this manner, the at least one test receiving area can be used to capture optical signals transmitted using the at least one light emitting element beyond the end of the at least one measurement time interval.

[0017] The at least one test time interval is longer than the at least one measurement time interval and the transmission time interval, such that the at least one test receiving area can be used to receive and convert optical signals for a longer period of time than the at least one measurement receiving area.

[0018] In this way, the at least one measurement receiving area and the at least one measurement time interval can be used to characterize a target state for the light emission based on the assumption that the eye safety, in particular the safety means, is functional, and the at least one test receiving area and the at least one test time interval can be used to characterize an actual state for the light emission for the eye safety, in particular for the at least one safety means.

[0019] If the amount of light characterized using the at least one test receiving variable is greater than the amount of light characterized using the at least one measured receiving variable by a specified tolerance limit, i.e., if the actual state of light emission deviates from the target state by a tolerance limit, it is concluded that the at least one test receiving region continues to capture echo signals derived from the optical signal transmitted using the at least one light-emitting element during the period between the end of the at least one measurement time interval and the end of the at least one test time interval. From this, it is concluded that there is an error in the limit of transmission of the optical signal. A fault condition is then generated to prevent the eye safety of the detection device from being compromised.

[0020] A tolerance limit for the comparison of the test and measurement reception variables can be advantageously specified, particularly at the end of the production line. The tolerance limit can advantageously be zero.

[0021] The measurement receiving areas and the test receiving areas can advantageously be receiving areas of the same type: in order to test the eye safety, in particular the functioning of the at least one safety means, some of the receiving areas can be configured as measurement receiving areas and other examples of the receiving areas can be configured as test receiving areas.

[0022] Advantageously, the at least one light emitting element can be used to transmit an optical signal, in particular in the form of a pulsed laser signal, which can be generated simply and precisely.

[0023] Advantageously, the detection device can operate according to the signal time-of-flight method, in particular the signal pulse time-of-flight method. Detection devices operating according to the signal pulse time-of-flight method can be designed and referred to as time-of-flight (TOF) systems, light detection and ranging (LiDAR) systems, laser detection and ranging (LaDAR) systems, etc.

[0024] Advantageously, the detection device can be designed as a scanning system. In this context, the monitored area can be sampled, i.e., scanned, using the optical signal. For this purpose, the propagation direction of the optical signal can be changed, in particular rotated, over the monitored area. This can involve using at least one signal deflection device, in particular a scanning device, a deflection mirror device, or the like. Alternatively, the detection device can be designed as a so-called flash system, in particular a flash LiDAR. A suitably diffused optical signal can simultaneously illuminate a relatively large portion of the monitored area or the entire monitored area.

[0025] Advantageously, the detection device can be designed as a laser-based distance measuring system. The laser-based distance measuring system can include a laser, in particular a diode laser, as a signal source. The laser can be used to transmit, in particular, a pulsed laser signal. The laser can be used to emit an optical signal in a wavelength range visible or invisible to the human eye. The receiver of the detection device can therefore comprise or consist of a sensor, in particular a point sensor, a line sensor, and / or an area sensor, in particular an (avalanche) photodiode, a photodiode line, a CCD sensor, an active pixel sensor, in particular a CMOS sensor, etc., designed for the wavelength of the transmitted optical signal. Advantageously, the laser-based distance measuring system can be designed as a laser scanner. The laser scanner can be used to scan the monitoring area, in particular with a pulsed laser signal, in particular a laser beam.

[0026] The present invention can be advantageously used in vehicles, particularly automobiles. The present invention can be advantageously used in land vehicles, particularly passenger cars, trucks, buses, motorcycles, etc., aircraft, particularly drones, and / or ships. The present invention can also be used in vehicles that can operate autonomously or at least semi-autonomously. However, the present invention is not limited to vehicles. The present invention can also be used in stationary motion, robotics, and / or machinery, particularly construction or transport machinery such as cranes, excavators, etc.

[0027] The detection device may advantageously be connected to or be part of at least one electronic control device of the vehicle or machine, in particular a driver assistance system and / or a chassis control system and / or a driver information device and / or a parking assistance system and / or a gesture recognition system, etc. In this way, at least some of the functions of the vehicle or machine can be performed autonomously or semi-autonomously.

[0028] The detection device can be used to detect stationary or moving objects, in particular vehicles, people, animals, plants, obstacles, road irregularities, in particular potholes or rocks, road boundaries, traffic signs, open spaces, in particular parking spaces, rainfall, etc., and / or movements and / or gestures.

[0029] In one advantageous configuration of the method, at least one measurement time interval and / or at least one test time interval and / or transmission time interval may be implemented to at least partially overlap in time; and / or at least one measurement time interval and / or at least one test time interval and / or transmission time interval can start simultaneously. In this way, the same optical signal can be at least intermittently received using at least one measurement receiving area and at least one test receiving area. This allows the respective determined reception variables to be compared with each other more effectively. Furthermore, the measurement reception variable and the test reception variable can be determined simultaneously in a time-saving manner.

[0030] By starting the time intervals at the same time, gaps can be avoided, which allows for a more effective comparison of the measured and test received variables.

[0031] Alternatively or additionally, the at least one measurement time interval and the at least one test time interval may start consecutively without overlapping, so that the determination of the measurement reception variable and the determination of the test reception variable may be performed consecutively.

[0032] In a further advantageous configuration of the method, determining at least one test reception variable and at least one measurement reception variable of spatially adjacent reception regions; and / or determining a measurement reception variable for each of at least two spatially adjacent measurement reception areas; and / or a test reception variable for each of at least two spatially adjacent test reception areas can be determined, in this way the same optical signal can be received using the receiving areas involved, which makes it possible to further improve the comparability of the determined reception variables.

[0033] Advantageously, the measurement reception variables of at least two spatially adjacent measurement reception areas can be determined. Alternatively or additionally, the test reception variables of at least two spatially adjacent test reception areas can be determined. In this way, a spatial resolution can be further obtained when capturing the optical signal. This makes it possible to determine, in particular, the direction from which the optical signal comes. Advantageously, the plurality of measurement reception areas and / or the plurality of test reception areas can be arranged in a matrix and / or rows.

[0034] In a further advantageous configuration of the method, At least one measurement time interval may be specified as having approximately the same length as the transmission time interval; And / or the at least one measurement time interval can be specified as not having a length longer than the at least one transmission time interval. In this way, the target state with respect to the light emission can be characterized more accurately using the at least one measurement receiving area, based on the assumption that the eye safety is functional, in particular that the at least one safety means is functional.

[0035] Advantageously, at least one measurement time interval can be specified as having a length not longer than at least one transmission time interval, in this way at least one measurement receiving area can be used during at least one measurement time interval to capture a maximum amount of light transmitted during the transmission time interval using at least one light emitting element when the eye safety is activated, in particular when the safety means is activated.

[0036] In a further advantageous configuration of the method, At least one eye safety test is performed during normal operation of the detection device; and / or at least one eye safety test is performed outside of normal operation of the detection device.

[0037] When checking eye safety during normal operation, the safety stops may be checked more frequently.

[0038] When testing eye safety outside of normal operation, all receiving areas may be used as measurement receiving areas instead during normal operation.

[0039] Advantageously, the eye safety check can be performed after the detection device is switched on, in this way malfunctions can be detected before normal operation begins.

[0040] In a further advantageous configuration of the method, at least one light emitting element can be used to transmit a modulated light signal, in this way information about at least one monitored area, in particular the distance, speed and / or direction of detected objects in the monitored area, can be determined more effectively, in particular more easily and / or more accurately.

[0041] Advantageously, the modulated optical signal can be transmitted in the form of light pulses. In this way, the detection device can operate in particular according to the time-of-flight method. Alternatively or additionally, the modulated optical signal can be transmitted as a continuous wave signal.

[0042] Advantageously, the at least one photoelectric element can be activated to transmit an optical signal, in particular by an electrical trigger signal, which can be generated using suitable means of the detection device, in particular the control device and / or the driver device.

[0043] In a further advantageous embodiment of the method, at least the stopping of at least one photoelectric element, at least one error signal, at least one visual, audible and / or tactile output signal, etc. may be generated as a fault condition.

[0044] By deactivating at least one photoelectric element, it is possible to ensure further transmission of the optical signal.

[0045] The error signal can be used to output information about an erroneous state of the detection device, in particular about the eye safety of the detection device. The error signal can in particular be processed automatically.

[0046] A visual, audible and / or tactile output signal may be used to directly notify a user of the detection device and / or maintenance personnel for the detection device of the presence of a fault.

[0047] Furthermore, the present invention provides the detection device has at least one safety means for limiting the duration of transmission of the optical signal to a specified transmission time interval to achieve eye safety, and at least one inspection device for the at least one safety means; The inspection device means for configuring at least one receiving area as a measurement receiving area for the purpose of generating, from at least one received optical signal, at least one measurement receiving variable characterizing an amount of light that can be captured using the at least one measurement receiving area in at least one measurement time interval; means for configuring at least one receiving area as a test receiving area for the purpose of generating, from at least one received optical signal, at least one test receiving variable characterizing an amount of light that can be captured using the at least one test receiving area during at least one test time interval; means for evaluating at least some of the received variables; means for generating at least one fault condition if at least one test receiving variable characterizes an amount of light that is greater than an amount of light characterized using at least one measured receiving variable outside the tolerance variables; have In this respect, the object of the detection device is achieved.

[0048] According to the present invention, the detection device has at least one inspection device for inspecting at least one safety means for limiting the transmission of the optical signal. The inspection device can be used to inspect whether the at least one safety means is functioning properly. The function of the at least one safety means is to limit the duration of the transmission of the optical signal. In this way, eye safety can be achieved using the at least one safety means. Therefore, the eye safety of the detection device can be inspected using the at least one inspection device.

[0049] The at least one inspection device can be used to determine if the at least one safety means does not stop transmitting the optical signal after a specified transmission time interval due to a malfunction. In this case, a fault condition can be generated using the means of the inspection device. The fault condition can include appropriate measures. In particular, at least one light-emitting element can be deactivated. Alternatively or additionally, at least one error signal and / or at least one visual, audible and / or tactile output signal can be generated.

[0050] In one advantageous embodiment, The at least one measurement receiving area and the at least one test receiving area may be formed from the same type of receiving area; And / or the at least one measurement receiving area and / or the at least one test receiving area may be separately configurable to record the receiving variables at different time intervals.

[0051] At least one measurement receiving area and / or at least one test receiving area may be formed from the same type of receiving area, and thus the receiving area of ​​at least one receiver can be configured as either a measurement receiving area or a test receiving area.

[0052] Alternatively or additionally, the at least one measurement receiving area and / or the at least one test receiving area may be separately operable to record the received variables at different time intervals. In this way, the measurement receiving area and the test receiving area can be activated for different time intervals.

[0053] In a further advantageous embodiment, The at least one receiver may have multiple point sensors, at least one line sensor, and / or at least one area sensor used to generate a respective reception area.

[0054] A point sensor is used to implement a specific reception area. The use of multiple point sensors makes it possible to create multiple reception areas. The point sensor may be, in particular, a photodiode.

[0055] In the case of a line sensor, multiple receiving areas are arranged in a row. Line sensors can be made more compact and / or easier to read than single point sensors arranged adjacent to each other. Line sensors can advantageously be realized as rows of diode linear arrays or area sensors, in particular CCD sensors, active pixel sensors, etc.

[0056] In the case of an area sensor, a plurality of receiving areas is arranged two-dimensionally, in particular in the form of a matrix, which can advantageously be realized as a CCD sensor, an active pixel sensor, or the like.

[0057] Additionally, line and area sensors can also be used for spatially resolved measurements.

[0058] Furthermore, the present invention provides the detection device has at least one safety means for limiting the duration of transmission of the optical signal to a specified transmission time interval to achieve eye safety, and at least one inspection device for the at least one safety means; The inspection equipment means for configuring at least one receiving area as a measurement receiving area for the purpose of generating, from at least one received optical signal, at least one measurement receiving variable characterizing an amount of light that can be captured using the at least one measurement receiving area in at least one measurement time interval; means for configuring at least one receiving area as a test receiving area for the purpose of generating, from at least one received optical signal, at least one test receiving variable characterizing an amount of light that can be captured using the at least one test receiving area during at least one test time interval; means for evaluating at least some of the received variables; means for generating at least one fault condition if at least one test receiving variable characterizes an amount of light that is greater than an amount of light characterized using at least one measured receiving variable outside the tolerance variables; have In this respect, the main purpose of this vehicle is achieved.

[0059] According to the invention, the vehicle comprises at least one detection device that complies with eye safety limits and that can be used to monitor at least one monitoring area outside the vehicle and / or inside the vehicle, in particular for objects.

[0060] In an advantageous embodiment, the vehicle may have at least one driver assistance system that may be used to operate the vehicle autonomously or semi-autonomously.

[0061] Advantageously, the at least one detection device can be functionally connected to at least one driver assistance system, so that information about the monitoring area, in particular object information determined using the at least one detection device, can be used in the at least one driver assistance system for controlling the autonomous or semi-autonomous operation of the vehicle.

[0062] Furthermore, the features and advantages indicated in relation to the method according to the invention, the detection device according to the invention and the vehicle according to the invention, as well as their respective advantageous configurations, apply in a corresponding manner to one another and vice versa. The individual features and advantages can naturally be combined with one another, resulting in further advantageous effects that exceed the sum of the individual effects.

[0063] Further advantages, features and details of the present invention will become apparent from the following description in which exemplary embodiments of the present invention are described in more detail with reference to the drawings. Those skilled in the art will also conveniently consider individually the features disclosed in combination in the drawings, the description and the claims and combine them to form further meaningful combinations. [Brief explanation of the drawings]

[0064] [Figure 1] FIG. 1 shows a front view of a vehicle having a driver assistance system and a LiDAR system for detecting objects in the direction of travel ahead of the vehicle. [Figure 2] 2 shows a functional diagram of a vehicle having the driver assistance system and LiDAR system of FIG. 1. [Figure 3] FIG. 3 shows a plan view of a detail from a receiver of the LiDAR system of FIGS. 1 and 2 having multiple receiving areas arranged in two dimensions. [Figure 4] From top to bottom, the time characteristics of the trigger input signal, the trigger output signal, the measurement integral signal for activating the measurement receiving area of ​​the receiver in FIG. 3, and the test integral signal for activating the test receiving area of ​​the receiver for controlling the laser of the LiDAR system in FIGS. 1 and 2 are shown, and the safety means of the LiDAR system is used to terminate the transmission of the laser signal using the laser after the transmission time interval. [Figure 5] Along the columns containing the receiver areas of Figure 3, a strength / receive area graph of the receive variable is shown, generated from the laser echo signal integrated over the integration time of the respective receive area, the receive areas are alternately activated as measurement receive area and test receive area using the respective integrated signal, and a safety means of the LiDAR system is used to terminate the transmission of the laser signal using the laser after the transmission time interval. [Figure 6] From top to bottom, the same time characteristics as in Figure 4 are shown, but the transmission of the transmission signal using the laser is not terminated after the transmission time interval. [Figure 7]Figure 5 shows the intensity / reception area graph of the reception variable, as well as the transmission of the transmission signal using the laser, which has not been terminated after the transmission time interval. DETAILED DESCRIPTION OF THE INVENTION

[0065] In the drawings, identical elements are labeled with identical reference numerals.

[0066] FIG. 1 shows a front view of a vehicle 10, for example in the form of a passenger car.

[0067] The vehicle 10 has an optical detection device, for example in the form of a LiDAR system 12. The LiDAR system 12 is designed as a laser scanner. For example, the LiDAR system 12 can be a near-field laser scanner (NFL). Figure 2 shows a functional diagram of the vehicle 10 having the LiDAR system 12.

[0068] As an example, the LiDAR system 12 is positioned on the front fender of the vehicle 10. The LiDAR system 12 can be used to monitor a surveillance area 14 in a direction of travel 16 ahead of the vehicle 10 for objects 18. The LiDAR system 12 can also be positioned at other points on the vehicle 10 and oriented in different directions. The LiDAR system 12 can also be positioned on the vehicle 10 for interior surveillance. The LiDAR system 12 can be used to determine object information, such as the distance, direction, and speed of the object 18 relative to the vehicle 10 or the LiDAR system 12, respectively, or corresponding characteristic variables.

[0069] The object 18 can be a stationary or moving object, such as another vehicle, a person, an animal, a plant, an obstacle, a road irregularity such as a pothole or a rock, a road boundary, a traffic sign, an open space such as a parking space, rain, etc. Human gestures can also be detected using the LiDAR system 12.

[0070] The LiDAR system 12 is connected to a driver assistance system 20 of the vehicle 10. The driver assistance system 20 can be used to operate the vehicle 10 autonomously or semi-autonomously.

[0071] The LiDAR system 12 comprises, for example, a sensor unit 22, for example in the form of an NFL sensor, and a control unit 24. The sensor unit 22 is connected to the control unit 24 via an interface 26, for example a low-voltage differential signaling (LVDS) interface, for example FPD-Link III. To generate the interface 26, the sensor unit 22 comprises a serializer 28 and the control unit 24 comprises a deserializer 30.

[0072] The sensor unit 22 includes a transmitting device 32 , a receiving device 34 , a driver and safety device 36 , and a serializer 28 .

[0073] The control unit 24 comprises a control and evaluation device 38 and a deserializer 30 .

[0074] The interface 26 can be used to transfer data from the receiving device 34 to the control and evaluation device 38. Furthermore, the interface 26 has a return channel. The return channel can be, for example, an I 2 It can be used by the control and evaluation device 38 to communicate with the receiving device 34 using the C protocol.

[0075] The transmitting device 32 has, for example, a laser 40, such as a diode laser, as a signal source. The laser 40 can be used, for example, to transmit a pulsed laser signal 42. The transmitting device 32 can optionally have at least one optical system, such as at least one optical lens, that can be used to influence, for example, diffuse and / or focus, the generated laser signal 42, as needed. The LiDAR system 12 can be designed as a scanning LiDAR system or a flash LiDAR system.

[0076] Additionally, the transmitting device 32 may optionally include a signal deflection device that can be used to direct the laser signal 42 into the monitored area 14. The signal deflection device may be changeable, for example rotatable. In this manner, the propagation direction of the laser signal 42 may be steered and the monitored area 14 may be sampled or scanned.

[0077] The transmitting device 32 is connected to the driver and safety device 36 via a control connection 44. The control connection 44 can be used to activate the laser 40 with a trigger output signal 46 from the driver and safety device 36 to transmit a laser signal 42. Figure 4 shows an example of details from the trigger output signal 46 over time.

[0078] The driver and safety device 36 is connected to the receiving device 34 via a signal connection 48. The signal connection 48 can be used to send a trigger input signal 50 from the receiving device 34 to the driver and safety device 36. Figure 4 shows an example of details from the trigger input signal 50 over time.

[0079] The driver and safety device 36 has a disconnectable connection between the signal connection 48 and the control connection 44 that can be used to transfer trigger input signals 50 from the signal connection 48 to the control connection 44 and send them to the sending device 32 as trigger output signals 46.

[0080] The driver and safety device 36 has a safety means 47 that can be used to interrupt the connection between the signal connection 48 and the control connection 44. The safety means 47 can be used, for example, to limit the transmission of the laser signal 42 to a specified transmission time interval TS. The transmission time interval TS is specified such that the transmitted light signal 42 is below eye safety limits. Thus, eye safety can be achieved when operating the LiDAR system 12.

[0081] The receiving device 34 comprises a receiver 52 and electronic components for controlling the receiver 52 and generating a receiving variable 54. The receiver 52 and the electronic components can be realized, for example, as an image sensor as a "system on chip", a so-called imager. Furthermore, the receiving device 34 comprises signal generating means which can be used to generate a trigger input signal 50.

[0082] The receiver 52 is realized as an area sensor, for example in the form of a CCD array. Alternatively, an active pixel sensor, a linear array of multiple photodiodes, etc. may be provided. Details from the receiver 52 are shown in plan view in Figure 3. The receiver 52 has multiple receiving areas 56 arranged adjacent to one another in multiple rows 58. The receiving areas 56 may also be referred to as "pixels."

[0083] The receiving region 56 can be used to convert optical signals, such as echo signals 60 from the laser signal 42 reflected by objects 18 in the monitored region 14, into corresponding electrical receive signals. The receive signals can be used to generate receive variables 54. The receive variables 54 can be used to characterize the receive echo signals 60, such as their amount of light or light energy.

[0084] The receive areas 56 may be activated for different time intervals TE during which their respective receive variables 54 may be generated from the incoming echo signals 60. The time intervals TE may also be referred to as "integration times." By way of example, receive areas 56 located in the same row 58 may be activated for the same time intervals TE.

[0085] The receiving device 34 may optionally have at its optical input side an echo signal deflection device and / or an optical system, for example an optical lens, that can be used to direct the echo signal 60 to the receiver 52 .

[0086] The receiving device 34 is connected to a control and evaluation device 38 by an interface 26 that includes a serializer 28 and a deserializer 30 .

[0087] The control and evaluation device 38 can be used to process the received variables 54 generated using the receiving device 34. For example, the control and evaluation device 38 can be used to obtain the received variables 54 and determine therefrom object variables, such as distance variables, direction variables and / or speed variables that characterize the distance, direction and / or speed of the detected object 18 relative to the LiDAR system 12 or relative to the vehicle 10.

[0088] Furthermore, the control and evaluation device 38 may be, for example, 2 The C protocol can be used to configure the receiver 52. For example, the receive area 56 can be activated with an appropriate integrating signal 64 for each time interval TE. The integrating signal 64 can be, for example, a square wave pulse having the length of the applicable time interval TE. The rising edge of the square wave pulse of the integrating signal 64 can be used to initiate each time interval TE and activate the applicable receive area 56 to capture the echo signal 60 for the duration of the square wave pulse.

[0089] Furthermore, the control and evaluation device 38 can be used to configure the driver and safety device 36. For example, the length of the transmission time interval TS, during which the laser 40 is used to transmit the laser signal 42, can be specified. Furthermore, the control and evaluation device 38 can be used to start the transmission time interval TS. The transmission time interval TS and the time interval TE of the reception area 56 can be started in a coordinated manner, for example, simultaneously.

[0090] Furthermore, the control and evaluation device 38 comprises a safety stop test means 62 which can be used to test the function of the safety means 47 of the driver and safety device 36 and to prevent further transmission of the laser signal 42 if a malfunction is detected.

[0091] For this purpose, the safety stop test means 62 is configured to provide a test time interval TE T Test integral signal 64 for activation during T Some of the receiving areas 56 are test receiving areas 56 T 47. Another example of the receiving area 56 is the measuring time interval TE M 64 for measuring integral signal for activation during M By measuring the receiving area 56 M It can be operated as.

[0092] Measurement time interval TE M is, for example, slightly shorter than the transmission time interval TS. The test time interval is the measurement time interval TE M and longer than the transmission time interval TS. T is specified so that the LiDAR system 12 operates below the eye safety limit.

[0093] Furthermore, the safety stop test means 62 is connected to the test receiving area 56 T Test receiving variables determined during inspection by 54 T A, measuring receiving area 56 M Measurement receiving variables determined by 54 M can be used to compare with test receiving variables 54 T However, the measurement receiving variable 54 M If the amount of light in the received echo signal 60 is greater than the amount of light in the received echo signal 60 characterized using the fault condition control means 63 of the safety stop testing means 62, a fault condition can be generated using the fault condition control means 63. For example, the fault condition control means 63 can be used to interrupt the connection between the signal connection 48 and the control connection 44 of the driver and safety device 36 as a fault condition.

[0094] The functions and components of the control and evaluation device 38 and the driver and safety devices 36 may be implemented centrally or locally. Some of the functions and components of the control and evaluation device 38 and the driver and safety devices 36 may also be integrated into the sending device 32 and / or the receiving device 34. The control and evaluation device 38, the driver and safety devices 36, and the driver assistance system 20 may also be partially combined. The functions of the control and evaluation device 38 and the driver and safety devices 36 are implemented by software and hardware.

[0095] A method for operating the LiDAR system 12 is described in more detail below: first, normal operation for monitoring the monitoring area 14, and then a test mode for testing the driver and safety means 47 of the safety device 36.

[0096] During normal operation, the control and evaluation device 38 is used to configure the receiving device 34 and initiate measurements. M and the same measurement integral signal 64 specified by the control and evaluation device 38 as M Measurement receiving area 56 M is the same measurement time interval TE for receiving the echo signal 60. M is activated over a period of time.

[0097] The receiving device 34 receives the measurement time interval TE M , the driver and safety device 36 transmits the trigger input signal 50 to the transmitting device 32 as a trigger output signal 46 via the control connection 44. In response to the trigger output signal 46, the laser 40 transmits the trigger input signal 50 to the transmitting device 32 over the measurement time interval TE M is used to transmit a pulsed laser signal 42 into the monitored area 14 for a duration of .times. ...

[0098] Measurement integral signal 64 M, the driver and safety device 36 is further used to start a specified transmission time interval TS. After the transmission time interval TS has elapsed, the safety means 47 is used to interrupt the connection between the signal connection 48 and the control connection 44, so that no further trigger output signals 46 are sent to the transmitting device 32. Thus, the transmission of the laser signal 42 is terminated. This allows, for example, the measurement integral signal 64 M When transmitting, the eye safety limit is prevented from being exceeded in the event of a malfunction.

[0099] The transmitted laser signal 42 is reflected back towards the LiDAR system 12, for example, by objects 18 within the monitored area 14. The measurement time interval TE M During this time, the reflected laser signal 42 is received as an echo signal 60 using a measurement receiving area 56, and the respective receiving variable 54 M is generated.

[0100] Received variable 54 M is transmitted to the control and evaluation device 38, which is located within the reception area 56 of the receiver 52. M 5 shows, as an example, a section of the amplitude image 66 along a column perpendicular to the rows 58 of the receiver 52.

[0101] Furthermore, the control and evaluation device 38 can be used to determine the received variables 54 M and from there, object variables, e.g., the reception area 56 for or respectively the LiDAR system 12 are obtained. M Distance, direction and / or velocity variables characterizing the distance, direction and / or velocity of the detected object 18 relative to the target object 18 may be determined.

[0102] The determined object variables are transmitted to a driver assistance system 20. The driver assistance system 20 is used to operate the vehicle 10 autonomously or semi-autonomously using the object variables.

[0103] In a test mode for testing the safety means 47 using the safety stop test means 62, the control and evaluation device 38 is used to configure the receiving device 34 as required and to start measurements. M and some of the receiving areas 56 are configured as test receiving areas 56 T For example, the row 58 including the receiving area 56 is configured as the measurement receiving area 56 M and test receiving area 56 T The measurement receiving area 56 is configured as M is the same measurement integral signal 64 specified by the control and evaluation device 38. M Measurement receiving area 56 M is the same measurement time interval TE for receiving the echo signal 60. M The test reception area 56 T is the same test integral signal 64 specified by the control and evaluation device 38. T Test reception area 56 T is the same test time interval TE T The echo signal 60 is ready to be received over the measurement time interval TE M is the test time interval TE T Starts at the same time.

[0104] The receiving device 34 receives the measurement time interval TE M , the laser 40 transmits a trigger input signal 50 to the driver and safety device 36 for a duration of TE. The driver and safety device 36 forwards the trigger input signal 50 to the transmitting device 32 as a trigger output signal 46. In response to the trigger output signal 46, the laser 40 transmits a trigger input signal 50 to the transmitting device 32 for a duration of TE. M is used to transmit a pulsed laser signal 42 into the monitored area 14 for a duration of .times. ...

[0105] Measurement integral signal 64 M When the time t begins, the driver and safety device 36 is further used to start a specified transmission time interval TS.

[0106] If the driver and safety device 36 is functioning correctly, the connection between the signal connection 48 and the control connection 44 is interrupted after the transmission time interval TS has elapsed, as in normal operation, so that the trigger output signal 46 is no longer transmitted to the transmitting device 32. Thus, the transmission of the laser signal 42 is terminated. The signal characteristics for this situation are shown in FIG.

[0107] Illuminated measurement receiving area 56 M is the measurement time interval TE M During this time, the laser signal 42 reflected by the object 18 in the monitored area 14 towards the LiDAR system 12 is received as an echo signal 60, and the respective measured received variable 54 M Furthermore, the echo signal 60 is generated during the test time interval TE T Illuminated test reception area 56 T Each test is received using the received variables 54 T is generated.

[0108] Measurement receiving variables 54 M and test reception variables 54 T is transmitted to the control and evaluation device 38, which receives the measurement signal from the measurement receiving area 56 of the receiver 52. M and test receiving area 56 T 5 shows, as an example, a section of the amplitude image 66 along a column perpendicular to the rows 58 of the receiver 52, during which the driver and safety devices 36 are functioning properly.

[0109] As shown in Figure 4, the transmission time interval TS is M Therefore, the trigger output signal 46 is slightly longer than the measurement time interval TE M , is used to activate the laser 40 for a further period of the trigger output signal 46 to transmit the laser signal 42 after the end of the measurement time interval TE. M It is not active outside the measurement reception area 56M However, the later portion of the echo signal 60 is not received within the test time interval TE T Test reception area 56 T As a result, the test reception area 56 T The measurement receiving area is 56 M 42. Therefore, the applicable measurement reception area 56 M 54, which characterizes the amount of light received using a measurement reception variable M 5, each adjacent test reception area 56 T Each test received variable 54 T The adjacent measurement receiving area 56 M Measurement of receiving variables 54 M and test receiving area 56 T Test receiving variables 54 T The intensity difference between adjacent test receiving variables 54 is within a specified tolerance limit, for example. T and measuring receiving variables 54 M are compared to each other. Because the intensity difference is within acceptable limits, no fault condition is generated using the safety shutdown test means 62.

[0110] If the driver and safety device 36 or the safety means 47 is not functioning properly, it may happen that the connection between the signal connection 48 and the control connection 44 is not interrupted after the transmission time interval TS has elapsed. Therefore, the trigger output signal 46 is still sent to the transmitting device 32. The transmission of the optical signal 42 continues after the transmission time interval TS has elapsed. The signal characteristics of this situation are shown in Figure 6. If the optical signal 42 is transmitted for a relatively long time, eye safety may be threatened.

[0111] As in fault-free operation, the laser signal 42 reflected by the object 18 in the monitored area 14 towards the LiDAR system 12 is measured over a measurement time interval TE M Between each measurement receiving area 56 M and a corresponding measured received variable 54M Furthermore, the echo signal 60 is generated during the test time interval TE T Between each test receiving area 56 T and the corresponding test reception variable 54 T is generated.

[0112] Measured receiving variables 54 as well as fault-free operation of the driver and safety devices 36 M and test reception variables 54 T are transmitted to the control and evaluation device 38. The control and evaluation device 38 is used to determine an amplitude image 66 that characterizes the intensity characteristics of the echo signals 60 along the receiving area 56 of the receiver 52. Figure 7, like Figure 5, shows a section of the amplitude image 66 along a column perpendicular to the rows 58 of the receiver 52, in this case where the driver and safety devices 36 are not functioning correctly.

[0113] 6, a malfunction means that the trigger output signal 46 continues after the end of the transmission time interval TS, and the laser 40 is still activated to transmit the laser signal 42. M After the end of the measurement, the trailing part of the echo signal 60 of the continued laser signal 42 is received in the measurement receiving area 56. M However, the later portion of the echo signal 60 is not received within the test time interval TE T Until the end of the test reception area 56 T As a result, the test reception area 56 T The measurement receiving area is 56 M The measurement receiving area 56 is exposed to the laser signal 42 for a much longer period of time than the measurement receiving area 56. M Measurement of receiving variables 54 M 7, compared to fault-free operation as shown in FIG. 5, for each adjacent test reception area 56 T Test receiving variables 54 T is significantly smaller than

[0114] Adjacent test receiving variables 54 T and measuring receiving variables 54 Mare compared with each other. M Measurement of receiving variables 54 M and test receiving area 56 T Test receiving variables 54 T Since the magnitude difference between is outside specified tolerance limits, a malfunction of the safety means 47 is assumed. The safety stop test means 62 is used to generate a fault condition in the form of an interruption to the connection between the control connection 44 and the signal connection 48 of the driver and safety device 36.

Claims

1. 1. A method for operating an optical detection device (12) arranged to monitor at least one monitoring area (14), comprising the steps of: At least one light emitting element (40) is activated to transmit at least one optical signal (42); At least one reflected optical signal (60) is received using at least two receiving areas (56) of at least one receiver (52); determining at least one received variable (54) using the at least one received optical signal (42); A method in which the functional safety of the optical detection device (12) is checked at least intermittently, the duration of the transmission of each of the optical signals (42) is limited to a specified transmission time interval (TS) to achieve eye safety of the optical detection device (12); The eye-safety of the optical detection device (12) is At least one of the receiving areas (56) is a measurement receiving area (56) Ｍ ), and at least one of the receiving areas (56) is configured as a test receiving area (56) Ｔ ) and At least one measurement time interval (TE Ｍ ) at least one measurement receiving area (56) Ｍ ) and at least one measured reception variable (54) characterizing the amount of captured light using Ｍ ), At least one test time interval (TE Ｔ At least one test receiving area (56) Ｔ at least one test reception variable (54) characterizing the amount of captured light using Ｔ ), The at least one test time interval (TE Ｔ ) is the at least one measurement time interval (TE Ｍ ) and the at least one test time interval (TE Ｔ ) is longer than the transmission time interval (TS), At least one test receiving variable (54 Ｔ ) is connected to said at least one measured received variable (54 Ｍ a fault condition is generated if the amount of light characterized using a threshold is greater than the amount of light characterized using a threshold outside a specified tolerance variable.

2. At least one measurement time interval (TE Ｍ ) and / or at least one test time interval (TE Ｔ ) and / or transmission time intervals (TS) are realized to at least partially overlap in time, and / or at least one measurement time interval (TE Ｍ ) and / or at least one test time interval (TE Ｔ ) and / or transmission time intervals (TS) start at the same time 2. The method of claim 1.

3. At least one test reception variable (54) in a spatially adjacent reception area (56) Ｔ ) and at least one measured receiving variable (54 Ｍ ) is determined, and / or at least two spatially adjacent measurement receiving areas (56 Ｍ ) each measured receiving variable (54 Ｍ ) is determined, and / or at least two spatially adjacent test receiving areas (56 Ｔ ) each test receiving variable (54 Ｔ ) is determined 2. The method of claim 1.

4. The at least one measurement time interval (TE Ｍ ) is designated as having approximately the same length as the transmission time interval (TS), and / or the at least one measurement time interval (TE Ｍ ) is specified as having a length not greater than at least one transmission time interval (TS) 2. The method of claim 1.

5. at least one eye-safety test is performed during normal operation of the optical detection device (12); and / or at least one eye-safety test is performed outside of normal operation of the optical detection device (12).

2. The method of claim 1.

6. 2. The method of claim 1, wherein at least one light emitting element (40) is used to transmit a modulated optical signal (42).

7. The generated fault condition is Deactivation of at least one photoelectric element; at least one error signal, or at least one visual, auditory and / or tactile output signal; 2. The method of claim 1, wherein the method is at least one of:

8. An optical detection device (12) for monitoring at least one monitoring area (14), comprising: having at least one light emitting element (40) for transmitting an optical signal (42); having at least two receiving areas (56) for receiving the reflected optical signal (42); at least one means (52) for determining a received variable (54) from the received optical signal (42); at least one means (38) for controlling said optical detection device (12) and for processing received variables (54); at least one means (62, 63) for checking the functional safety of the optical detection device (12), In the optical detection device (12), the optical detection device (12) has at least one safety means (36, 47) for limiting the duration of the transmission of the optical signal (42) to a specified transmission time interval (TS) in order to achieve eye safety, and at least one inspection device (38, 62, 63) for the at least one safety means (36, 47), The inspection device (38, 62, 63) At least one measurement time interval (TE) is determined from at least one received optical signal (42). Ｍ ) at least one measurement receiving area (56) Ｍ at least one measured reception variable (54) characterizing the amount of light that can be captured using the Ｍ At least one receiving area (56) is measured to generate a receiving area (56). Ｍ ) and means for configuring the At least one test time interval (TE) is detected from at least one received optical signal (42). Ｔ At least one test receiving area (56) Ｔ at least one test reception variable (54) characterizing the amount of light that can be captured using the Ｔ At least one receiving area (56) is set as a test receiving area (56) for the purpose of generating a Ｔ ) and means for configuring the means for evaluating at least some of said received variables (54); At least one test receiving variable (54 Ｔ ) at least one measured receiving variable (54 Ｍ means for generating at least one fault condition when the amount of light characterized using the threshold is outside the tolerance variable and is greater than the amount of light characterized using the threshold; An optical detection device (12), characterized in that it comprises:

9. At least one measurement receiving area (56 Ｍ ) and at least one test receiving area (56 Ｔ ) are formed from reception areas (56) of the same type, and / or at least one measurement receiving area (56 Ｍ ) and / or at least one test receiving area (56 Ｔ ) at different time intervals (TE Ｍ , T.E. Ｔ ) can be separately configured to record received variables (54) 9. The optical detection device according to claim 8, characterized in that it comprises:

10. 10. The optical detection device according to claim 8 or 9, characterized in that at least one receiver (52) comprises a plurality of point sensors, at least one line sensor and / or at least one area sensor used to generate a respective reception area (56).

11. A vehicle (10) having at least one optical detection device (12) for monitoring at least one monitoring area (14), said at least one optical detection device (12) comprising: at least one light emitting element (40) for transmitting an optical signal (42); at least two receiving areas (56) for receiving the reflected optical signal (42); at least one means (52) for determining a received variable (54) from the received optical signal (42); at least one means (38) for controlling said optical detection device (12) and for processing received variables (54); at least one means (62, 63) for checking the functional safety of said optical detection device (12); A vehicle (10) having the optical detection device (12) has at least one safety means (36, 47) for limiting the duration of the transmission of the optical signal (42) to a specified transmission time interval (TS) in order to achieve eye safety, and at least one inspection device (38, 62, 63) for the at least one safety means (36, 47), The inspection device (38, 62, 63) At least one measurement time interval (TE) is determined from at least one received optical signal (42). Ｍ ) at least one measurement receiving area (56) Ｍ at least one measured reception variable (54) characterizing the amount of light that can be captured using the Ｍ At least one receiving area (56) is measured to generate a receiving area (56). Ｍ ) and means for configuring the At least one test time interval (TE) is detected from at least one received optical signal (42). Ｔ At least one test receiving area (56) Ｔ at least one test reception variable (54) characterizing the amount of light that can be captured using the Ｔ At least one receiving area (56) is set as a test receiving area (56) for the purpose of generating a Ｔ ) and means for configuring the means for evaluating at least some of said received variables (54); At least one test receiving variable (54 Ｔ ) at least one measured receiving variable (54 Ｍ means for generating at least one fault condition when the amount of light characterized using the threshold is greater than the amount of light characterized using the threshold. A vehicle (10) comprising:

12. 12. Vehicle according to claim 11, characterized in that the vehicle (10) comprises at least one driver assistance system (20).

Images