Security system and procedures with a security system

Abstract

Security system (1) for locating a person (2) and / or an object (8) in a monitored area, comprising a control and evaluation unit (3), comprising at least one radio tracking system (4) for determining the position of the person (2) and / or the object (8) in the monitored area, comprising at least one spatially resolving sensor (7) for determining the presence of the person (2) and / or the object (8) in a protective field of the spatially resolving sensor (7), where the protective field is located within the monitoring area, wherein the radio tracking system (4) comprises arranged radio stations (5), wherein at least one radio transponder (6) is arranged on the person (2) and / or the object (8), wherein the radio tracking system (4) can be used to determine the position data of the person (2) and / or the object (8), wherein the position data from the radio stations (5) of the radio tracking system (4) can be transmitted to the control and evaluation unit (3), and status information about the protective field can be determined by means of the spatially resolving sensor (7), where status information about the protective field can be transmitted from the position-resolving sensor (7) to the control and evaluation unit (3), characterized in that the control and evaluation unit (3) is designed to evaluate the position data of the radio tracking system (4) and the status information of the location-resolving sensor (7) and and if a person (2) and / or an object (8) is detected by the radio tracking system (4) in the monitoring area, the control and evaluation unit (3) is designed to put the location-resolving sensor (7) into operation with a non-reduced security level, and if no person (2) and / or object (8) is detected by the radio tracking system (4) in the monitoring area, the control and evaluation unit (3) is designed to put the location-resolving sensor (7) into operation with a reduced security level, whereby the switching between the different security levels is carried out by switching operating modes.

Description

[0001] The present invention relates to a security system for locating a person according to the preamble of claim 1 and a method for locating a person according to the preamble of claim 14.

[0002] Safety systems used in safety technology must operate with particular reliability and intrinsically safety and therefore meet high safety requirements, for example the EN13849 standard for machinery safety and the EN61496 device standard for electro-sensitive protective devices (ESPE).

[0003] In an industrial plant, a required safety level is almost always defined only once for a machine. This definition is made during the machine's development or later, when safety technology is subsequently added. Validation, i.e., the acceptance of safety and the safety level, also occurs only once, namely during commissioning. This is rigid and inflexible.

[0004] To date, safety sensors have usually been developed and approved for one or two specified safety levels. For example, a light curtain is certified for Type 2 and Type 4, while a laser scanner is certified for Type 3 (Types 2 to 4, for example, according to IEC / EN 61496-2). The manufacturer specifies the safety level of each sensor.

[0005] The higher the safety level for which the sensor is to be approved, the higher the requirements are regarding diagnostic coverage, redundancies, documentation during the development process, and the developers' competencies regarding functional safety.

[0006] In this context, ISO EN 13849-1 was developed, which defines performance levels similarly to safety levels. ISO EN 13849-1 takes the Machinery Directive into account and considers safety functions both qualitatively and quantitatively.

[0007] For example, the minimum reflectivity of objects that an optical safety sensor must be able to detect within its monitoring range also depends on the safety level. The higher the safety level, the lower the minimum reflectivity of the objects that must be reliably detected. This means that the certification-relevant tests on an optoelectronic sensor that is intended to meet PL d are carried out using test specimens that have a different reflectivity than a sensor with PL b.

[0008] DE10 2019 131 833 A1 discloses a method for verifying the setting of specified safety functions of a field device in process and automation technology. This involves defining a safety level required at the measuring point and / or the field device, whereby the specified safety level defines the target setting of the specified safety functions of the field device. Typically, there are several safety levels, each of which defines a target setting of the specified safety functions. The safety levels are valid for all field devices. After configuring the field device, a suitable safety level for the field device and / or measuring point can be selected and verified and adjusted using the method.

[0009] Safety sensors are usually operated at the highest available safety level. This means that the safety sensors usually restrict operational processes much more than the current hazard situation would require. The required safety level is determined based on the statistically worst case scenario. This means that it is sufficient for the assumption that the worst case scenario could occur at some point in the product life cycle, possibly weighted by its probability of occurrence.

[0010] DE 20 2020 107 300 U1 discloses a security system for locating at least one person or at least one object in a surveillance area, comprising at least one control and evaluation unit, at least one radio location system, and at least one spatially resolving sensor for determining the position of the person or object, wherein the radio location system has arranged radio stations, wherein at least one radio transponder is arranged on the person or object, wherein position data of the person or object can be determined by means of the radio location system, wherein the position data can be transmitted from the radio stations of the radio location system to the control and evaluation unit, and at least presence data of the person or object can be determined by means of the spatially resolving sensor, wherein the surveillance area has several sectors and several passage areas between the sectors,At least one spatially resolving sensor is assigned to each passage area, wherein the control and evaluation unit is designed to cyclically compare the position data of the radio location system and the presence data of the spatially resolving sensor in each passage area and to cyclically generate status information for the sector.

[0011] DE 10 2019 114 854 A1 discloses a device for the energy-efficient execution of a safety function on a technical system, comprising a protective device for detecting a triggering event of the safety function and a processing unit for executing a safety-related response of the safety function depending on the detection by the protective device. Furthermore, the device can be selectively operated in a first and a second operating mode. In the first operating mode, the protective device and / or the processing unit are configured to detect the triggering event and / or execute the safety-related response according to a first quality factor, and in the second operating mode according to a second quality factor. The second quality factor is lower than the first quality factor, and in the second operating mode, the protective device and / or the processing unit can be operated at reduced power to save energy.

[0012] DE 10 2020 114 488 B3 discloses an optoelectronic safety sensor for protecting a machine. It comprises a light receiver for optically detecting object data and a control and evaluation unit configured to use the object data to determine whether a safety-critical object is detected in the environment of the machine and, if so, to trigger a safety-related reaction. The control and evaluation unit is further configured to adapt the sensitivity of a criterion for determining whether a safety-critical object is detected depending on previously and / or simultaneously detected objects.

[0013] DE 43 40 756 A1 discloses a laser distance determination device according to the pulse transit time method with a pulsed laser which sends controlled light pulses into a measuring area, a photoreceiving arrangement which receives the light pulses reflected by an object located in the measuring area, and an evaluation circuit which, taking into account the speed of light, determines a distance signal characteristic of the distance of the object from the pulsed laser from the time between the emission and reception of a light pulse, wherein a light deflection device is arranged between the measuring area and the pulsed laser, which deflects the successive light pulses into the measuring area at increasingly changing angles and simultaneously outputs an angular position signal representative of its current angular position to the evaluation circuit.and that the evaluation circuit determines the location of the object within the measuring range from the distance signal and the angular position signal, wherein the distance angle range is preferably greater than 90° and in particular less than 270° and preferably approximately 180° and expediently the pulsed light beams define a preferably horizontal scanning plane.

[0014] DE 10 2021 101 180 A1 discloses a method with a security system and security system for locating at least one mobile object, with at least one control and evaluation unit, with at least one radio location system, wherein the radio location system has at least three arranged radio stations, wherein at least one radio transponder is arranged on the object, wherein position data of the radio transponder and thus position data of the object can be determined by means of the radio location system, wherein the position data can be transmitted from the radio station of the radio location system to the control and evaluation unit, wherein the control and evaluation unit is designed to cyclically record the position data of the radio transponder, wherein a first checking unit is provided, wherein the first checking unit is connected to the control and evaluation unit, wherein the control and evaluation unit is checked by the first checking unit.

[0015] One object of the invention is to provide a safety system with a safety sensor, wherein the safety sensor can have different safety levels. The aim is to increase productivity in an industrial plant. At the same time, the safety level required at the current time should not be undercut.

[0016] The object is achieved according to claim 1 by a security system for locating a person and / or an object in a surveillance area, with a control and evaluation unit, with at least one radio location system for determining the position of the person and / or the object in the surveillance area, with at least one spatially resolving sensor for determining the presence of the person and / or the object in a protective field of the spatially resolving sensor, wherein the protective field is arranged within the surveillance area, wherein the radio location system has arranged radio stations, wherein at least one radio transponder is arranged on the person and / or the object, wherein position data of the person and / or the object can be determined by means of the radio location system, wherein the position data can be transmitted from the radio stations of the radio location system to the control and evaluation unit,and status information about the protective field can be determined by means of the spatially resolving sensor, wherein status information about the protective field can be transmitted from the spatially resolving sensor to the control and evaluation unit, wherein the control and evaluation unit is designed to evaluate the position data of the radio location system and the status information of the spatially resolving sensor, and if a person and / or an object is detected by the radio location system in the monitoring area, the control and evaluation unit is designed to put the spatially resolving sensor into operation with a non-reduced safety level, and if no person and / or object is detected by the radio location system in the monitoring area, the control and evaluation unit is designed to put the spatially resolving sensor into operation with a reduced safety level.

[0017] The object is further achieved according to claim 14 with a method with a security system for locating a person and / or an object in a surveillance area, with a control and evaluation unit, with at least one radio location system for determining the position of the person and / or the object in the surveillance area, with at least one spatially resolving sensor for determining the presence of the person and / or the object in a protective field of the spatially resolving sensor, wherein the protective field is arranged within the surveillance area, wherein the radio location system has arranged radio stations, wherein at least one radio transponder is arranged on the person and / or the object, wherein position data of the person and / or the object are determined by means of the radio location system, wherein the position data are transmitted from the radio stations of the radio location system to the control and evaluation unit,and status information on the protective field is determined by means of the spatially resolving sensor, wherein status information on the protective field is transmitted from the spatially resolving sensor to the control and evaluation unit, wherein the control and evaluation unit evaluates the position data of the radio location system and the status information of the spatially resolving sensor, and if a person and / or an object is detected by the radio location system in the monitoring area, the control and evaluation unit sets the spatially resolving sensor to operation with a non-reduced safety level, and if no person and / or object is detected by the radio location system in the monitoring area, the control and evaluation unit sets the spatially resolving sensor to operation with a reduced safety level.

[0018] The inventive solution assumes that, in addition to the locally mounted location-resolving sensors or safety sensors, a radio tracking system or secure localization system is installed in a production facility or logistics center. This system determines the positions of the people, objects, or mobile machines present with an accuracy of approximately one meter or more. For this purpose, all people, objects, and / or mobile machines, for example, are equipped with at least one radio transponder.

[0019] If, according to the invention, the security level of the sensor is temporarily reduced locally, then productivity is increased.

[0020] The term "functionally safe" is to be understood in the sense of the aforementioned or comparable standards; that is, measures have been taken to control errors up to a specified safety level. The safety system can therefore be designed to be intrinsically safe. The safety system and / or at least the safe sensor also generate non-safe data, such as raw data, point clouds, or the like. "Not safe" is the opposite of "safe," referring to non-safe devices, transmission paths, evaluations, and the like, and therefore the aforementioned fail-safe requirements are not met.

[0021] A safety level or performance level (PL value) is determined according to IEC / EN 13849. The PL value is classified from a (low contribution to risk reduction) to e (high contribution to risk reduction). In contrast to the technical requirements of the EN 954-1 standard, the ISO 13849 standard allows for several ways to achieve a required PL value. The user can therefore combine suitable measures that best meet their requirements. Technical constraints or cost considerations may play a role here. Predefined safety structures must still be used.

[0022] IEC / EN 13849-1 takes the Machinery Directive into account and considers safety functions both qualitatively and quantitatively. To classify different levels of safety-related performance, it defines five performance levels (PL a, b, c, d, e), which represent average probability values ​​of a dangerous failure per hour. EN ISO 13849-1 specifies an iterative process for the design and validation of safety-related parts of control systems (SRP / CS).

[0023] To ensure safe operation, machine or system controls must meet certain requirements. Four key parameters play a particularly important role in the evaluation of electrical or electronic safety systems: The architecture and structure of the system is a characteristic of the safety system. Safety systems can be single-channel, dual-channel, or multi-channel. While single-channel systems typically respond to errors with failure, dual- or multi-channel systems can check each other and detect potential errors. The metric for the architecture is the HFT value (Hardware Fault Tolerance). If the HFT value is 0, there is no hardware fault tolerance, and any error can lead to failure. For example, dual-channel systems are better than single-channel systems.

[0024] Diagnostic coverage is a key metric of a safety system. Both single-channel and dual-channel (or even multi-channel) structures can fail. However, if the structure's functionality is tested regularly, a failure or defect can be detected. Diagnostic coverage (DC) indicates the probability of revealing errors through testing. Safety systems must be tested to verify their continued functionality. Diagnostic coverage depends on the quality of the test.

[0025] A failure rate is a characteristic of a safety system. If the failure rate is low, there is little need to fear defects. For example, if the failure rate for a sensor is zero, theoretically it will never fail and it will always display the correct sensor result. Since this does not correspond to practice, another device or test is required. The lower the failure rate of safety units, the less there is to fear that a failure will lead to the failure of the safety function. The failure rate indicates the number of failures per unit of time. Typically, a scale of 1 failure in 10 9 Hours were chosen (this is an extremely small unit, since only one failure in about 100,000 years corresponds to this; this value is also called 1 fit, failure in time).

[0026] A common-cause failure is a characteristic of a safety system. This refers to factors that affect multiple systems simultaneously. Thus, a single cause has a fatal effect on all devices. Even if systems have two or more channels, are even tested, and rarely fail, a single negative influence can affect or even shut down all systems. In electronics, for example, extreme voltage levels are known to render several units unusable at once. These common-cause failures (CCFs) must be avoided at all times.

[0027] The secure radio tracking system determines and tracks the location of all people or objects within the surveillance area. For example, it causes spatially resolving sensors located in the immediate vicinity of people or objects to adopt a higher security level. For example, spatially resolving sensors located outside the immediate vicinity of people or objects are forced to adopt a lower security level.

[0028] For example, the signals for changing the security level are sent by the secure radio positioning system from the control and evaluation unit to the position-resolving sensors. For example, the position-resolving sensor has a secure input or a secure input interface.

[0029] The radio stations are used for radio-based communication and runtime measurement with the mobile radio transponders and for forwarding communication and runtime measurement values ​​to the control and evaluation unit or the RTLS server.

[0030] The control and evaluation unit or a central RTLS server receives the measured signal propagation times and uses them to determine the position values ​​of the existing radio transponders.

[0031] The radio transponders are located by measuring the propagation times of radio signals that are exchanged cyclically between the radio transponders and several fixed radio stations. This works very well when the signals are transmitted with sufficient signal strength and along a straight or direct propagation path.

[0032] The signals from a radio transponder are received by several stationary radio stations or anchor stations, and a transit time measurement, e.g., "time of arrival" (TOA) or "time difference of arrival" (TDOA), creates the basis for positioning. The calculation or estimation of a radio transponder's position is then performed by the control and evaluation unit, for example, a central RTLS (Real-Time Location System) server, which is connected to all radio stations or anchor stations via a wireless or wired data connection. This positioning mode is called RTLS (Real-Time Location System) mode.

[0033] The spatially resolving sensor can, for example, be arranged in a fixed location. However, it is also possible, for the spatially resolving sensor to be arranged in a mobile, i.e., mobile, manner. For example, the spatially resolving sensor is arranged on a vehicle, in particular on an autonomous vehicle. The radio transponders are also arranged in a fixed or mobile manner. For example, the spatially resolving sensor is designed to monitor at least the entire area of ​​a protected field or protected area.

[0034] The spatially resolving sensor for at least the area-wide monitoring of a protected area is a distance measurement sensor. The distance sensor provides distance values ​​in at least two-dimensional space. The sensor outputs measured values ​​with distance and angle information. For example, the distance is determined using the time-of-flight method or triangulation method.

[0035] For example, the spatially resolving sensor is an optoelectronic sensor.

[0036] In an optoelectronic sensor, such as a time-of-flight sensor, the light emitted by a light transmitter, which is then remitted by the person or object, is received by a light receiver. The light's time of flight from the moment of transmission to the moment of reception by the person or object is evaluated, allowing the distance to the person or object to be determined. This involves locating, for example, the determination of distance and angle.

[0037] Switching between the different safety levels can be achieved by switching the operating mode. When switching the operating mode from a calculation with, for example, high remission to low remission, an autonomous vehicle might brake abruptly until it is slow enough for the shorter protective field. This problem can be solved by switching early enough so that the autonomous vehicle has enough time to brake slowly.

[0038] The sensor's security level can also be downgraded to the point where no security level is present. The sensor is then no longer part of the safety system or architecture. However, the sensor can still be used, for example, to prevent collisions between objects.

[0039] During normal operation, the control and evaluation unit sends a signal to the local, spatially resolving sensor when it should switch to the lower safety level. For example, a type of operating mode switch using a 1-out-of-2 input, in the simplest case, a 1-out-of-2 input on the spatially resolving sensor.

[0040] Alternatively, the local spatially resolving sensor could receive a digital signal that causes the spatially resolving sensor to switch to the low security level for a specified time.

[0041] The security level will not be reduced in the following cases, for example: If communication between the radio transponder and radio stations is faulty or the radio location system cannot provide reliable data.

[0042] If it cannot be ensured that all persons or objects in the vicinity of a machine are wearing a radio transponder, such as a truck driver delivering material to be unloaded by autonomous vehicles. For example, there is a fault in a lock designed to ensure that only persons with a valid radio transponder are in the monitored area.

[0043] In the case of a planned close human-machine interaction. For example, a person is near a machine, but the machine should not be stopped. In this case, for example, the spatially resolving sensor should have a better response time and / or better spatial resolution than the radio location system. For example, a light curtain can detect the intrusion of a human finger, while the radio location system can only detect the position of the person's body.

[0044] In these cases, for example, the control and evaluation unit sends a signal to the spatially resolving sensors in order to operate them at the highest available safety level.

[0045] The security level is reduced, for example, in the following cases: Communication between the radio transponder and the radio station works well enough to ensure the response time required for the current situation. And the radio tracking system provides reliable data indicating, for example, that a program sequence of the radio tracking system is not significantly disrupted.

[0046] All persons wear a radio transponder. There is no person without a radio transponder. It can be ensured that all persons or moving objects in the vicinity of a machine or within the monitoring area wear a functioning radio transponder. There may also be persons and / or objects in the monitoring area who do not themselves wear a radio transponder, but whose position is known from other sources, for example, because a person is operating a forklift truck equipped with a functioning radio transponder, which is therefore automatically assigned to the person operating the forklift truck. If collisions between autonomous vehicles and static or stationary objects are also to be prevented, then all static objects must also be entered, for example, in a map of the radio positioning system.

[0047] For example, the safety of people who do not carry a radio transponder can be guaranteed because they do not have access to the surveillance area, for example because an access area with an access gate is provided to which only people with a radio transponder are allowed access.

[0048] In a further development of the invention, during operation with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out ambient light tests with a lower quality due to lower requirements with regard to ambient light resistance.

[0049] With a reduced safety level, for example, some requirements regarding ambient light resistance may be omitted. For example, ambient light tests may be omitted or at least performed, but these do not necessarily result in an error message or a reduction in sensor functionality. For example, only a warning message is issued indicating that ambient light may have been detected. This results in higher productivity because there is less downtime.

[0050] In a further development of the invention, during operation with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed such that, if contamination of a front screen of the spatially resolving sensor is detected, only a warning is issued by the control and evaluation unit, but switching outputs of the spatially resolving sensor remain active.

[0051] For example, a threshold for the contamination warning is shifted. This results in the sensor remaining in proper normal operation longer. Ideally, the windshield is cleaned before the spatially resolving sensor has to switch its switching outputs because the received light intensity is lower than a permitted comparison threshold. This results in fewer failures due to a dirty windshield, for example. This is particularly advantageous if the spatially resolving sensor is operated in a dusty environment (e.g., in a wood processing plant). This results in increased productivity.

[0052] In a further development of the invention, during operation with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer error control measures.

[0053] With a reduced safety level, fewer errors need to be addressed. Therefore, fewer errors need to be accumulated in a failure mode and effect analysis (FMEA). This allows for a lower diagnostic coverage. As a result, self-tests of the spatially resolving sensor need to be performed less frequently, or sometimes even eliminated during ongoing operation. This results in fewer false alarms and thus higher productivity.

[0054] In a further development of the invention, during operation with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer or no more multiple evaluations.

[0055] With a reduced safety level, for example, multiple evaluations are no longer necessary or fewer multiple evaluations are acceptable. This leads to a shorter response time, which, for example, enables a higher maximum travel speed, which in turn leads to higher productivity.

[0056] A reduced safety level requires lower MTTFd (mean time to dangerous failure) requirements. For example, a performance level PL d requires a high level, namely 30 years ≤ MTTFD ≤ 100 years. For example, a performance level PL b requires a medium level, namely 10 years ≤ MTTFD ≤ 30 years.

[0057] The information transmission from the radio location system or the control and evaluation unit to the local position-resolving safety sensors can be carried out in various ways.

[0058] For example, via cable or line, usually with a translation to a suitable safe interface such as Ethernet, IO-Link Safety or a 1-out-of-N signal.

[0059] For example, the information can be transmitted wirelessly directly to the local, location-resolving security sensor, for example via Bluetooth, Bluetooth low Energy, etc.

[0060] For example, the information can be transmitted via the radio transponder on the object and then from there via cable or wirelessly to the location-resolving sensor.

[0061] In a further development of the invention, a first checking unit is provided, wherein the first checking unit is connected to the control and evaluation unit, wherein the control and evaluation unit is checked by the first checking unit.

[0062] The first verification unit or a secure RTLS watchdog controller monitors the control and evaluation unit, whereby the first verification unit, for example, checks the plausibility of the determined position data, sends switching signals for a security status of the individual radio transponders or, for example, initiates verification unit reset signals to the radio transponders depending on the situation.

[0063] The first verification unit and the control and evaluation unit thus form at least a single-channel system with testing according to ISO 13849 or, optionally, a dual-channel system. The first verification unit provides the necessary diagnostic mechanisms, as required, for example, by the relevant safety standards.

[0064] The first verification unit, or an RTLS watchdog controller, monitors and diagnoses the safety system and the control and evaluation unit and executes the safety system's safety functions. The first verification unit uses the control and evaluation unit, for example, as a communication relay. Specifically, the first verification unit monitors, for example, correct communication between the radio transponders, the radio stations, and the control and evaluation unit, checks the timing behavior of all components, and performs consistency checks on the acquired data. If necessary, the first verification unit also uses a function block executed in the control and evaluation unit or the RTLS server.

[0065] The first verification unit, or the RTLS watchdog controller, uses position data or verified position data from the RTLS system and, for example, information about hazardous locations, details of the operating environment, etc., provided in advance via configuration, to assess local hazards. In the simplest case, this is done by determining the distances between people and hazardous locations and initiating risk-reducing measures if a safety limit is exceeded. Risk reduction is based, for example, on the verification unit sending the radio transponders a safe shutdown or switching signal, which they then transmit to a connected machine, for example, or, in the case of a radio transponder attached to a person, a warning signal or instructions to the person.

[0066] For example, a large number of radio transponders are provided, for example on all mobile machines and persons and, if necessary, also on stationary machines.

[0067] Radio transponders can perform additional tasks and therefore differ from conventional radio transponders or tags. In addition to supporting the RTLS system's tracking function, they also perform the following functions: Radio-based determination of one's own position, for example inverse radio location based on flashing signals from various radio stations.

[0068] Alternatively, the radio transponder can measure the propagation time of the radio station signals and send feedback of the propagation time differences to the first verification unit or the RTLS watchdog controller, after which the calculated radio transponder positions can optionally be checked for plausibility.

[0069] Furthermore, for example, position, status and diagnostic information is transmitted to the control and evaluation unit and to the first verification unit.

[0070] In order to perform these functions, the radio transponders, for example, have bidirectional communication with the first verification unit.

[0071] The first verification unit checks the plausibility of the determined position data and, if errors or implausible measured values ​​are detected, sends signals to switch a security status of the radio transponder in question.

[0072] The RTLS system, which uses the radio positioning system to determine the position data of the radio transponder and thus the position data of the objects, uses radio positioning to determine the positions of all radio transponders in a fixed time frame. The RTLS system operates with bidirectional communication between the radio transponders and the radio stations. This is because the radio transponders can also determine their own positions and transmit the location results to the control and evaluation unit using a radio return channel, for example, a UWB return channel. This provides the control and evaluation unit or the RTLS server with two independently determined pieces of position information for comparison: first, the position information determined by the radio stations, and second, the position information determined by the radio transponders.Alternatively, the radio transponders can measure the propagation times of the signals transmitted by the radio stations, and only the determined propagation times are reported back to the control and evaluation unit for plausibility checks. This is sufficient for verifying the position determination. Additionally, bidirectional communication can be used to forward diagnostic information or other status information determined locally on the transponders to the first verification unit or the watchdog controller.

[0073] In a further development of the invention, the radio location system is an ultra-wideband radio location system, wherein the frequency used is in the range from 3.1 GHz to 10.6 GHz, wherein the transmission energy per radio station is a maximum of 0.5 mW.

[0074] An absolute bandwidth of an ultra-wideband radiolocation system is at least 500 MHz or a relative bandwidth is at least 20% of the central frequency.

[0075] The range of such a radio location system is, for example, 0 to 50 m. The short duration of the radio pulses is used for location.

[0076] The radio location system therefore only transmits radio waves with low energy.

[0077] In addition to the UWB positioning system mentioned above, another radio technology could also be used for positioning.

[0078] The connection between the positioning and communication functions in the UWB system could also be split into two separate systems. For example, the UWB system is planned to handle only positioning, while an additional Wi-Fi network is used for data transmission.

[0079] In a further development of the invention, the spatially resolving sensor is an ultrasonic sensor or a radar sensor.

[0080] An ultrasonic sensor emits ultrasound and evaluates the reflected sound waves, i.e., the echo signals. Frequencies starting at 16 kHz are used. Detection ranges from a few centimeters to many meters can be achieved.

[0081] A radar sensor is a sensor that emits a so-called primary signal as a focused electromagnetic wave, receives echoes reflected from people or objects as a secondary signal, and evaluates them according to various criteria. This involves positioning, for example, determining distance and angle.

[0082] Position information, or the position itself, can be obtained from the received waves reflected by the person or object. As already mentioned, the angle or direction to the object and the distance to the person or object can be determined from the time difference between the transmission and reception of the signal. Furthermore, the relative movement between the transmitter and the person or object can also be determined, for example, by simply taking multiple measurements at intervals. The concatenation of individual measurements provides the distance traveled and the absolute speed of the object. With sufficient resolution of the radar sensor, the contours of the person or object can be detected.

[0083] For example, due to the antenna design, radiation from the radar sensor is largely focused in one direction. The antenna's radiation pattern then has a so-called lobe shape.

[0084] The wavelength of radar lies in the short-wave to microwave range of radio waves. A pulse radar sensor transmits pulses with a typical duration in the low microsecond range and then waits for echoes. The pulse propagation time is the time between the transmission and reception of the echo. This is used to determine distance.

[0085] Instead of adjusting the antenna(s), the scanning beam direction of a pulse radar sensor can also be controlled electronically using phased antenna arrays. This allows multiple objects to be targeted in rapid succession and tracked virtually simultaneously.

[0086] The radar sensor operates at a power of approximately 10 mW, for example. This power is so low that it poses no health risks. The radar frequency approved for this application, for example, is in the range of 76-77 GHz, corresponding to a wavelength of approximately 4 mm.

[0087] In a further development of the invention, the spatially resolving sensor is designed for at least spatial monitoring of a monitoring area.

[0088] In a further development of the invention, the optoelectronic sensor is a laser scanner, a safety laser scanner, a 3D camera, a stereo camera or a time-of-flight camera.

[0089] For position detection, the spatially resolving sensor, laser scanner, safety laser scanner, 3D camera, stereo camera, or time-of-flight camera monitors a two-dimensional or three-dimensional protective field or a measurement data contour. This can also be synonymously referred to as a monitoring field.

[0090] For example, if a solid state laser scanner is downgraded from performance level type d to performance level type c or performance level type b, then a higher minimum remission from the objects can be assumed in the safety calculation.

[0091] This means that the objects to be detected need not be assumed to be as black as they appear. For example, a test rod during acceptance. More light reaches the receiver because the object reflects and scatters more light. This results in higher received energy at the same distance, or the same amount of received energy at a greater distance.

[0092] This results in a greater safe range and thus a larger protective field. This gives an autonomous vehicle, for example, a wider field of vision, enabling a higher maximum driving speed and thus greater productivity.

[0093] A 3D camera, for example, also monitors a protected area using a large number of recorded distance values. A 3D camera has the advantage of being able to monitor a volume-like protected area.

[0094] A stereo camera, for example, also monitors a protected area or protected field using a large number of recorded distance values. The distance values ​​are determined based on the two cameras of the stereo camera, which are mounted at a base distance from each other. A stereo camera also has the advantage of being able to monitor a volume-like protected area.

[0095] A time-of-flight camera determines distance values ​​based on the measured time of light, which is determined by an image sensor. A time-of-flight camera also has the advantage of being able to monitor a volumetric or spatial protected area.

[0096] In a further development of the invention, a control and evaluation unit of the spatially resolving sensor is designed to carry out an evaluation on the basis of a higher minimum remission of the object when operating with a reduced safety level.

[0097] A higher minimum remission from the objects can be assumed. This results in a higher safe maximum range of the sensor. This allows for a larger protective field. For example, an autonomous vehicle can be realized with a larger protective field. This allows the autonomous vehicle to drive faster, which in turn leads to higher productivity.

[0098] The received energy depends quadratically on the distance to the object. In the case of reflected light, the light path is "doubled," as the light is radiated from the transmitter to the object and then back to the receiver. Remission can also be referred to as "detectable remission" or, colloquially, as reflectivity.

[0099] In a further development of the invention, the spatially resolving sensor is a light grid. A light grid preferably has a light grid transmitter in a first housing and a light grid receiver in a second housing. A protective field is formed between the light grid transmitter and the light grid receiver.

[0100] In a further development of the invention, a control and evaluation unit of the light grid is designed to carry out an evaluation on the basis of a larger opening angle of light receivers of the light grid during operation with a reduced safety level.

[0101] For a light curtain, larger opening angles are permitted at a reduced safety level. For example, a light curtain can open + / - 5° at a distance of 3 m between the transmitter and receiver, compared to + / - 2.5° at a higher safety level.

[0102] During operation with a larger opening angle, the light curtain is less susceptible to vibrations.

[0103] For example, with a reduced security level, a higher transmission power is also possible, since fewer errors have to be assumed to comply with the maximum opening angle.

[0104] The invention will be explained below with reference to further advantages and features, using exemplary embodiments, with reference to the accompanying drawings. The figures of the drawing show: Fig. 1 a security system.

[0105] Fig.1 shows a security system (1) for locating a person (2) and / or an object (8) in a surveillance area (10), with a control and evaluation unit (3), with at least one radio location system (4) for determining the position of the person (2) and / or the object (8) in the surveillance area (10), with at least one spatially resolving sensor (7) for determining the presence of the person (2) and / or the object (8) in a protective field (11) of the spatially resolving sensor (7), wherein the protective field (11) is arranged within the surveillance area (10), wherein the radio location system (4) has arranged radio stations (5), wherein at least one radio transponder (6) is arranged on the person (2) and / or the object (8), wherein position data of the person (2) and / or the object (8) can be determined by means of the radio location system (4), wherein the position data are received from the radio stations (5) of the radio location system (4) to the control and evaluation unit (3),and by means of the spatially resolving sensor (7) status information about the protective field (11) can be determined, wherein status information about the protective field (11) can be transmitted from the spatially resolving sensor (7) to the control and evaluation unit (3), wherein the control and evaluation unit (3) is designed to evaluate the position data of the radio location system (4) and the status information of the spatially resolving sensor (7) and if a person (2) and / or an object (8) are detected by the radio location system (4) in the monitoring area (10), the control and evaluation unit (3) is designed to put the spatially resolving sensor (7) into operation with a non-reduced security level, and if no person (2) and / or no object (8) are detected by the radio location system (4) in the monitoring area (10), the control and evaluation unit (3) is designed to put the spatially resolving sensor (7) into operation with a reduced security level.,

[0106] The solution assumes that, in addition to the locally mounted position-resolving sensors (7) or safety sensors, a radio location system (4) or secure localization system is installed in a production facility or logistics center. This system determines the positions of the people (2), objects (8), or mobile machines present with an accuracy of approximately one meter or more. For this purpose, all people (2), objects (8), and / or mobile machines, for example, are equipped with at least one radio transponder (6).

[0107] If the safety level of the sensor (7) is temporarily reduced, productivity is increased.

[0108] The secure radio location system (4) determines and tracks the location of all persons (2) or objects (8) in the surveillance area (10). For example, it causes the spatially resolving sensors (7) located in the immediate vicinity of persons (2) or objects (8) to adopt a higher security level. For example, spatially resolving sensors (7) not located in the immediate vicinity of persons (2) or objects (8) are caused to adopt a lower security level.

[0109] The signals for changing the security level are sent, for example, by the secure radio positioning system (4) from the control and evaluation unit (3) to the spatially resolving sensors (7). For example, the spatially resolving sensor (7) has a secure input or a secure input interface.

[0110] The spatially resolving sensor (7) can, for example, be arranged in a stationary manner. However, it is also provided, for example, that the spatially resolving sensor (7) is arranged in a mobile, i.e., mobile manner. For example, the spatially resolving sensor (7) is arranged on a vehicle, in particular on an autonomous vehicle. The radio transponders are, for example, also arranged in a stationary or mobile manner. For example, the spatially resolving sensor (7) is designed for at least the area-wide monitoring of a protective field (11) or protected area.

[0111] The spatially resolving sensor (7) for at least area-wide monitoring of a protected area is, for example, a distance measurement sensor. The distance sensor provides distance values ​​in at least two-dimensional space. The sensor (7) outputs measured values ​​with distance and angle information. For example, the distance is determined using a time-of-flight method or triangulation method.

[0112] For example, the spatially resolving sensor (7) is an optoelectronic sensor.

[0113] In an optoelectronic sensor, such as a time-of-flight sensor, the light emitted by a light transmitter, which is remitted by the person (2) or the object (8), is received by a light receiver, and the light's time of flight from the emission to the reception by the person (2) or the object (8) is evaluated, allowing the distance to the person (2) or the object (8) to be determined. This involves locating, namely, for example, the determination of distance and angle.

[0114] Downgrading or reducing the security level of the local sensor (7) can affect the following aspects: A higher minimum remission from the objects (8) can be assumed. This results in a higher safe maximum range of the sensor (7). This allows for a larger protective field (11). For example, an autonomous vehicle can be realized with a larger protective field (11). This allows the autonomous vehicle to drive faster, which in turn leads to higher productivity.

[0115] The different security levels can be switched by switching the operating mode.

[0116] When using a light grid as a sensor (7), larger opening angles are permitted at a reduced safety level. For example, with a light grid, + / - 5° at a distance of 3 m between transmitter and receiver is permitted, compared to + / - 2.5° at a higher safety level. For example, with a reduced safety level, a higher transmission power is also possible, since fewer errors must be assumed to maintain the maximum opening angle.

[0117] During normal operation, the control and evaluation unit (3) sends a signal to the local spatially resolving sensor (7) when it should switch to the lower safety level.

[0118] Alternatively, the local spatially resolving sensor (7) could receive a digital signal that causes the spatially resolving sensor (7) to switch to the low security level for a predetermined time.

[0119] The information transmission from the radio location system (4) or the control and evaluation unit (3) to the local position-resolving safety sensors (7) can be transmitted in various ways.

[0120] For example, via cable or line, usually with a translation to a suitable safe interface such as Ethernet, IO-Link Safety or a 1-out-of-N signal.

[0121] For example, the information can be transmitted wirelessly directly to the local, spatially resolving security sensor (7), for example via Bluetooth, Bluetooth low Energy, etc.

[0122] For example, the information can be transmitted via the radio transponder (6) on the object (8) and then from there via cable or wirelessly to the location-resolving sensor (7).

[0123] Optionally, a first checking unit is provided, wherein the first checking unit is connected to the control and evaluation unit (3), wherein the control and evaluation unit (3) is checked by the first checking unit.

[0124] The first verification unit or a secure RTLS watchdog controller monitors the control and evaluation unit (3), wherein the first verification unit, for example, checks the plausibility of the determined position data, sends switching signals for a security status of the individual radio transponders (6) or, for example, initiates verification unit reset signals to the radio transponders (6) depending on the situation.

[0125] The first verification unit and the control and evaluation unit (3) thus form at least a single-channel system with testing according to ISO 13849 or, optionally, a dual-channel system. The first verification unit provides the necessary diagnostic mechanisms, as required, for example, by the relevant safety standards. Reference symbol: 1 security system 2 people 3 Control and evaluation unit 4 Radio location system 5 radio stations 6 radio transponders 7 spatially resolving sensor 8 Object 9 first review unit 10 Surveillance area 11 Protective field

Claims

[1] Security system (1) for locating a person (2) and / or an object (8) in a surveillance area, with a control and evaluation unit (3), with at least one radio location system (4) for determining the position of the person (2) and / or the object (8) in the surveillance area, with at least one spatially resolving sensor (7) for determining the presence of the person (2) and / or the object (8) in a protective field of the spatially resolving sensor (7), wherein the protective field is arranged within the monitoring area, wherein the radio location system (4) has arranged radio stations (5), wherein at least one radio transponder (6) is arranged on the person (2) and / or the object (8), wherein position data of the person (2) and / or the object (8) can be determined by means of the radio location system (4), wherein the position data can be transmitted from the radio stations (5) of the radio location system (4) to the control and evaluation unit (3), and status information on the protective field can be determined by means of the spatially resolving sensor (7), wherein status information on the protective field can be transmitted from the spatially resolving sensor (7) to the control and evaluation unit (3), characterized by that the control and evaluation unit (3) is designed to evaluate the position data of the radio location system (4) and the status information of the position-resolving sensor (7) and and if a person (2) and / or an object (8) are detected by the radio location system (4) in the monitoring area, the control and evaluation unit (3) is designed to put the spatially resolving sensor (7) into operation with a non-reduced security level, and if no person (2) and / or no object (8) are detected by the radio location system (4) in the monitoring area, the control and evaluation unit (3) is designed to put the spatially resolving sensor (7) into operation with a reduced security level, wherein the switching between the different security levels takes place by switching the operating mode. [2] Security system (1) according to claim 1, characterized by that when operating with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out ambient light tests with a lower quality due to lower requirements regarding ambient light resistance. [3] Security system (1) according to one of the preceding claims, characterized bythat during operation with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed so that if contamination of a front screen of the spatially resolving sensor is detected, only a warning is issued by the control and evaluation unit, but switching outputs of the spatially resolving sensor remain active. [4] Security system (1) according to one of the preceding claims, characterized by that when operating with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer error control measures. [5] Security system (1) according to one of the preceding claims, characterized by that when operating with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer or no more multiple evaluations. [6] Security system (1) according to one of the preceding claims, characterized by that a first checking unit (9) is provided, wherein the first checking unit (9) is connected to the control and evaluation unit (3), wherein the control and evaluation unit (3) is checked by the first checking unit (9). [7] Security system (1) according to one of the preceding claims, characterized by that the radio location system (4) is an ultra-wideband radio location system, the frequency used being in the range from 3.1 GHz to 10.6 GHz, the transmission energy per radio station (5) being a maximum of 0.5 mW. [8] Security system (1) according to one of the preceding claims, characterized by that the spatially resolving sensor (7) is an ultrasonic sensor or a radar sensor. [9] Security system (1) according to one of the preceding claims, characterized by that the spatially resolving sensor (7) is designed for at least spatial monitoring of a monitoring area [10] Security system (1) according to claim 1, characterized by that the spatially resolving sensor is a laser scanner (14), a safety laser scanner, a 3D camera, a stereo camera or a time-of-flight camera. [11] Security system (1) according to one of the preceding claims, characterized by that a control and evaluation unit of the spatially resolving sensor is designed to carry out an evaluation on the basis of a higher minimum remission of the object when operating with a reduced safety level. [12] Security system (1) according to claim 1, characterized by that the spatially resolving sensor is a light grid. [13] Security system (1) according to claim 12, characterized by that a control and evaluation unit of the light grid is designed to carry out an evaluation on the basis of a larger opening angle of light receivers of the light grid when operating with a reduced safety level. [14] Method with a security system (1) for locating a person (2) and / or an object (8) in a surveillance area, with a control and evaluation unit (3), with at least one radio location system (4) for determining the position of the person (2) and / or the object (8) in the surveillance area, with at least one spatially resolving sensor (7) for determining the presence of the person (2) and / or the object (8) in a protective field of the spatially resolving sensor (7), wherein the protective field is arranged within the surveillance area, wherein the radio location system (4) has arranged radio stations (5), wherein at least one radio transponder (6) is arranged on the person (2) and / or the object (8), wherein position data of the person (2) and / or the object (8) are determined by means of the radio location system (4), wherein the position data are transmitted from the radio stations (5) of the radio location system (4) to the control and evaluation unit (3), and status information on the protective field is determined by means of the spatially resolving sensor (7), wherein status information on the protective field is transmitted from the spatially resolving sensor (7) to the control and evaluation unit (3), characterized by that the control and evaluation unit (3) evaluates the position data of the radio location system (4) and the status information of the position-resolving sensor (7) and and if a person (2) and / or an object (8) is detected by the radio location system (4) in the monitoring area, the control and evaluation unit (3) sets the spatially resolving sensor (7) to operation with a non-reduced security level, and if no person (2) and / or no object (8) is detected by the radio location system (4) in the monitoring area, the control and evaluation unit (3) puts the spatially resolving sensor (7) into operation with a reduced security level, wherein the switching between the different security levels takes place by switching the operating mode.

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