DE202022106398U1 - Security system with a security system - Google Patents

Abstract

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 of the object (8) in the monitoring 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), the protective field being arranged within the monitoring area, wherein the radio location system (4) has arranged radio stations (5), at least one radio transponder (6) being 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 about the protective field can be determined by means of the spatially resolving sensor (7),
wherein status information about the protective field can be transmitted from the spatially 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 location system (4) and the status information of the spatially 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 set the spatially resolving sensor (7) to operation with a non-reduced security level offset,
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) is designed to switch the spatially resolving sensor (7) into operation with a reduced security level offset.

Description

The present invention relates to a security system for locating a person according to the preamble of claim 1.

Safety systems used in safety technology must work particularly reliably and intrinsically safe and therefore meet high safety requirements, for example the EN13849 standard for machine safety and the EN61496 device standard for non-contact protective devices (BWS).

In an industrial plant, a required safety level is almost exclusively set once for a machine. The determination is made while the machine is being developed or afterwards if it is subsequently equipped with safety technology. The validation, i.e. the acceptance of the security and the security level, only takes place once, namely during commissioning. This is rigid and inflexible.

Up to now, safety sensors have usually been developed and approved for one or two specified safety levels. For example, a light grid is certified for type 2 and type 4, a laser scanner for type 3 (type 2 to 4, for example, according to IEC/EN 61496-2). The manufacturer specifies which safety level the respective sensor has.

The higher the security level to which you want to approve the sensor, the higher the requirements are for diagnostic coverage, redundancies, documentation during the development process, and developer competencies with regard to functional safety.

In this environment, ISO EN 13849-1 was coined, which defines the performance level similarly to the safety level. ISO EN 13849-1 takes the Machinery Directive into account and considers safety functions both qualitatively and quantitatively.

For example, the minimum reflectivity of objects that an optical security sensor must be able to detect within its surveillance area also depends on the security level. The higher the security level, the lower the minimum reflectivity of the objects that must be safely detected. This means that the certification-relevant tests on an optoelectronic sensor that is supposed to meet PL d are carried out with test specimens that have a different reflectivity than a sensor with PL b.

The DE102019131833A1 discloses a method for checking the setting of specified safety functions of a field device in process and automation technology. This includes determining a security level required at the measuring point and/or on the field device, whereby the specified security level defines the target setting of the specified security functions of the field device. As a rule, there are several security levels, each of which defines a target setting for the specified security functions. The security levels are valid for all field devices. After configuring the field device, a security level that matches the field device and/or the measuring point can be selected and checked and adjusted using the method

Safety sensors are usually operated with the highest safety level available. This means that the safety sensors usually restrict operational processes much more than the current dangerous situation would require. The design of the required security level is based on the statistically worst case. This means that it is sufficient for the assumption if the worst case can occur at some point in the product cycle, if necessary weighted by its probability of occurrence.

One object of the invention is to provide a security system with a security sensor, wherein the security sensor can have different security levels. Productivity should be increased in an industrial plant. At the same time, the security level required at the current time should not be fallen below.

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, the protective field being arranged within the monitoring area, the radio location system having arranged radio stations, at least one radio transponder being arranged on the person and / or the object, by means of The radio positioning system can be used to determine position data of the person and/or the object, the position data being able to be transmitted from the radio stations of the radio positioning system to the control and evaluation unit, and status information about the protective field can be determined by means of the spatially resolving sensor, whereby status information for protection can be determined field can be transmitted from the spatially resolving sensor to the control and evaluation unit, the control and evaluation unit being designed to evaluate the position data of the radio positioning system and the status information of the spatially resolving sensor and when a person and/or an object is detected by the radio positioning system in the monitoring area the control and evaluation unit is designed to put the spatially resolving sensor into operation with a non-reduced security level, and if no person and/or no 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 in to move to an operation with a reduced security level.

The solution according to the invention assumes that in a production plant or a logistics center, in addition to the locally installed spatially resolving sensors or safety sensors, a radio location system or secure localization system is also installed that the positions of the people present, objects or mobile machines with an accuracy of around a meter or more precisely. For this purpose, all people, objects and/or, for example, mobile machines are provided with at least one radio transponder.

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

The term "functionally safe" is to be understood in the sense of the mentioned or comparable standards, i.e. measures have been taken to control errors up to a specified safety level. The security system can therefore be designed to be intrinsically safe. The security system and/or at least the secure sensor also generate non-secure data, such as raw data, point clouds or the like. Not safe is the opposite term too safe, for non-safe devices, transmission paths, evaluations and the like and the above-mentioned requirements for error safety are therefore not met.

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 several ways to achieve a required PL value. The user can therefore combine suitable measures that come closest to his ideas. Technical constraints or cost aspects can play a role here. Specified safety structures must still be used.

IEC/EN 13849-1 takes the Machinery Directive into account and considers safety functions both qualitatively and quantitatively. To classify different safety-related performance levels, 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 a control system (SRP/CS, safety-related parts of control systems).

• Eine Architektur und Struktur des Systems ist eine Kenngröße des Sicherheitssystems. Sicherheitssysteme können einkanalig, zweikanalig oder mehrkanalig aufgebaut sein. Während einkanalige Systeme in der Regel auf Fehler mit einem Versagen reagieren, so können zwei- oder mehrkanalige Systeme sich gegenseitig prüfen und eventuelle Fehler erkennen. Die Messgröße für die Architektur ist der HFT-Wert (aus dem Englischen: Hardware Fault Tolerance). Wenn der HFT-Wert 0 ist, so liegt keine Hardwarefehlertoleranz vor und ein beliebiger Fehler kann zum Versagen führen. Eine Zweikanaligkeit ist beispielsweise besser als eine Einkanaligkeit.

In order for the controls of machines or systems to work safely, they must meet certain requirements. There are four key parameters that 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 usually react to errors with failure, dual- or multi-channel systems can check each other and detect any errors. The measurement 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 is better than single-channel.

A diagnostic coverage level is a parameter of the safety system. Both single-channel and dual-channel (or even multi-channel) structures can fail.

However, if the function of the structure is tested regularly, a failure or defect can be detected. The degree of diagnostic coverage (DC) indicates the probability with which the errors will be revealed by a test. Security systems must be tested to prove whether they still work. The degree of diagnostic coverage depends on the quality of the test.

A failure rate is a parameter of the 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 show the correct sensor result. Since this does not correspond to the practical situation, 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. A scale of 1 failure in 10 ⁹ hours is usually chosen (this is an extremely small unit, since only one failure in around 100,000 years corresponds to this; this value is also referred to as 1 fit, failure in time).

A common cause failure is a characteristic of the safety system. This refers to factors that affect several systems at the same time. This means that a single cause has a fatal effect on all devices. Even if systems have two or more channels, these are even tested and rarely fail, a single negative influence can affect all systems or even switch them off. In electronics, for example, extreme voltage levels are known to render several units unusable at once. These common cause failures (CCF) must always be avoided.

The secure radio location system determines and tracks the whereabouts of all people or objects in the surveillance area. For example, it causes the spatially resolving sensors that are in the immediate vicinity of people or objects to adopt a higher level of security. For example, spatially resolving sensors that are not in the immediate vicinity of people or objects are prompted to adopt a lower security level.

The signals for changing the security level are, for example, sent by the secure radio location system from the control and evaluation unit to the spatially resolving sensors. For example, the spatially resolving sensor has a secure input or a secure input interface.

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

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

The radio transponders are located by measuring the transit time of radio signals, which are exchanged cyclically between the radio transponders and several fixed radio stations. This works very well if the signals are transmitted with sufficient signal strength and on straight or direct propagation paths.

The signals of a radio transponder are received by several fixed radio stations or anchor stations and the basis for positioning is created using a transit time measurement, e.g. Time of Arrival (TOA) or Time Difference of Arrival (TDOA). The calculation or estimation of the position of a radio transponder is then carried out on the control and evaluation unit, for example a central RTLS server (Real-Time Location System server), which is connected to all radio stations or anchor stations via a wireless or wired data connection. This mode of positioning is called RTLS mode (Real-Time Location System mode).

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

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

For example, the spatially resolving sensor is an optoelectronic sensor.

With an optoelectronic sensor, for example a time-of-flight sensor, the light emitted by a light transmitter, which is remitted by the person or object, is received by a light receiver and the light time of flight from emission to reception by the person or object is evaluated, thereby increasing the distance the person or object can be determined. This involves positioning, namely the determination of distance and angle, for example.

The different security levels can be switched over by switching the operating mode. When switching operating modes from the calculation with, for example, high remission to low remission, an autonomous vehicle would possibly brake abruptly until it is slow enough for the shorter protective field. This problem can be solved by switching over so early that the autonomous vehicle has enough time to brake slowly.

The security level of the sensor can also be downgraded to such an extent that there is no longer a security level. The sensor is then no longer part of the security system or security architecture. However, the sensor can still be used to avoid collisions between objects, for example.

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

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 predetermined time.

• Falls eine Kommunikation zwischen Funktransponder und Funkstationen fehlerhaft ist oder das Funkortungssystem keine zuverlässigen Daten liefern kann.

For example, the security level is not reduced in the following cases:

• If communication between the radio transponder and radio stations is faulty or the radio location system cannot provide reliable data.

If it cannot be ensured that all people or objects that are near a machine have a radio transponder. For example, a truck driver delivering material to be unloaded by autonomous vehicles. For example, there is an error in a lock that is supposed to ensure that only people with a valid radio transponder are in the surveillance area.

When close person-machine interaction is planned. For example, a person is near a machine and the machine should not be stopped. Here, for example, it is provided that the spatially resolving sensor has a better response time and/or a better spatial resolution than the radio location system. For example, a light curtain can detect an intrusion of a human finger, while the radio positioning system can only detect the position of the person's body.

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 security level.

• Eine Kommunikation zwischen Funktransponder und Funkstation funktioniert ausreichend gut, um die für die aktuelle Situation notwendige Ansprechzeit zu gewährleisten. Und das Funkortungssystem liefert zuverlässige Daten, wonach beispielsweise ein Programm-Ablauf des Funkortungssystems nicht maßgeblich gestört ist.

For example, the security level is reduced in the following cases:

• Communication between the radio transponder and the radio station works sufficiently well to ensure the response time necessary for the current situation. And the radio location system provides reliable data, according to which, for example, a program sequence of the radio location system is not significantly disrupted.

All people wear a radio transponder. There is no person without a radio transponder. It can be ensured that all people or moving objects that are near a machine or within the monitoring area have a functioning radio transponder. There may also be people and/or objects in the surveillance area who do not have a radio transponder themselves, but whose position is otherwise known, for example because a person is operating a forklift that is equipped with a functioning radio transponder, which is therefore also automatically activated Person assigned to the forklift. If collisions between autonomous vehicles and static or stationary objects are also to be prevented, then all static objects must also be entered on a map of the radio location system, for example.

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

In a further development of the invention, when operating with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out external light tests with a lower quality due to lower requirements with regard to external light resistance.

With a reduced safety level, for example, some requirements regarding resistance to external light may be omitted. For example, extraneous light tests can be omitted or at least carried out, but these do not necessarily lead to an error message or do not necessarily lead to a reduction in sensor function. For example, only a warning message is issued that extraneous light may have been detected. This results in higher productivity because there is less downtime.

In a further development of the invention, when operating with a reduced security level, a control and evaluation unit of the spatially resolving sensor is designed. If contamination of a windshield 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 are active remain.

For example, a threshold for the pollution warning is moved, for example. This means that the sensor remains in proper normal operation for longer. Ideally, for example, 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 means, for example, fewer breakdowns due to a dirty windshield. This is particularly interesting if the spatially resolving sensor is operated in a dusty environment (e.g. in a wood processing facility). This results in higher productivity.

In a further development of the invention, 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.

With a reduced security level, fewer errors need to be managed. This means that fewer errors need to be accumulated in an error mode effect analysis (FMEA for short). This allows for a lower level of diagnostic coverage. As a result, self-tests from the spatially resolving sensor need to be carried out less frequently or sometimes no longer need to be carried out during ongoing operation. This results in fewer false alarms and therefore higher productivity. In a further development of the invention, when operating with a reduced security level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer or no more multiple evaluations.

With a reduced security 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.

With a reduced security level, lower requirements are placed on an MTTFd (= “mean time to dangerous failure”). 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.

The information transmission from the radio location system or the control and evaluation unit to the local spatially resolved security sensors can be transmitted in various ways.

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

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

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

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.

The first checking unit or a secure RTLS watchdog controller monitors the control and evaluation unit, with the first checking unit, for example, checking the plausibility of the specific position data, sending switching signals for a security status of the individual radio transponders or, for example, initiating checking unit reset signals to the radio transponders depending on the situation.

The first checking unit and the control and evaluation unit thus form at least a single-channel system with testing according to ISO 13849 or optionally a two-channel system. The first verification unit provides the necessary diagnostic mechanisms, such as those required by the relevant safety standards.

The first checking unit or an RTLS watchdog controller is used to monitor and diagnose the security system and the control and evaluation unit and carries out security functions of the security system. The first checking unit uses the control and evaluation unit, for example as a communication relay. Specifically monitors the first verification For example, the unit ensures correct communication between the radio transponders, the radio stations and the control and evaluation unit, checks the time behavior of all components and carries out consistency checks on the data determined. If necessary, the first checking unit also uses a function block for this purpose, which is executed in the control and evaluation unit or the RTLS server.

The first checking unit or the RTLS watchdog controller uses position data or checked position data from the RTLS system and, for example, information about danger spots, details of the operating environment, etc. provided in advance via configuration, in order to assess the local threats. In the simplest case, this is done by determining the distances between people and danger areas and taking risk-reducing measures if they fall below a safety limit. A risk reduction is based, for example, on the fact that the checking unit sends the radio transponders a safe switch-off or switching signal, which they pass on, for example, to a connected machine or, in the case of a radio transponder on a person, pass on a warning signal or instructions for action to the person.

For example, a large number of radio transponders are provided, for example on all mobile machines and people and possibly also on stationary machines.

• Funkbasierte Bestimmung der eigenen Position, beispielsweise eine inverse Funkortung auf Basis von Blink-Signalen der verschiedenen Funkstationen.

The radio transponders can have additional tasks and therefore differ from conventional radio transponders or tags. In addition to supporting the location function of the RTLS system, the following functions are also added:

• Radio-based determination of one's own position, for example inverse radio positioning based on flashing signals from various radio stations.

Alternatively, a transit time measurement of the radio station signals can be carried out by the radio transponder and the transit time differences can be reported back to the first checking unit or the RTLS watchdog controller, after which the calculated radio transponder positions can optionally be checked for plausibility.

Furthermore, for example, position, status and diagnostic information is transmitted to the control and evaluation unit and to the first checking unit.

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

The first checking 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.

The RTLS system, according to which position data of the radio transponder and thus position data of the objects can be determined using the radio positioning system, uses radio positioning to determine the positions of all radio transponders in a fixed time grid. The RTLS system works with bidirectional communication between the radio transponders and the radio stations. The reason for this is that the radio transponders can also determine their position themselves and use a radio return channel, for example a UWB return channel, to transmit the result of the location to the control and evaluation unit. This means that two independently determined position pieces of information are available for comparison in the control and evaluation unit or in the RTLS server. Namely, firstly, the position information determined by the radio stations and secondly, the position information determined by the radio transponders. Alternatively, the radio transponders can be used to carry out transit time measurements of the signals emitted by the radio stations and only the determined transit times can be reported back to the control and evaluation unit for plausibility checks. This is sufficient to check the plausibility of the position determination. In addition, bidirectional communication can be used to pass on diagnostic information or other status information that was determined locally on the transponders to the first checking unit or the watchdog controller.

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

For an ultra-wideband radiolocation system, an absolute bandwidth is at least 500 MHz or a relative bandwidth is at least 20% of the central frequency.

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.

The radio location system therefore only emits radio waves with low energy.

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

The connection of the location and communication function in the UWB system could also be divided into two separate systems. For example, it is planned that the UWB system only takes care of the location and an additional WLAN network is used for data transmission.

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

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

A radar sensor is a sensor that emits a so-called primary signal as a bundled electromagnetic wave, receives the echoes reflected from people or objects as a secondary signal and evaluates them according to various criteria. This involves positioning, namely the determination of distance and angle, for example.

Position information or the position can be obtained from the received waves reflected from 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 sending and receiving the signal. Furthermore, the relative movement between the transmitter and the person or object can also be determined, for example by a simple multiple measurement at intervals of time. The sequence of individual measurements provides the distance and the absolute speed of the object. If the radar sensor has the appropriate resolution, the contours of the person or object can be recognized.

For example, radiation from the radar sensor is largely focused in one direction due to the antenna design. The radiation characteristic of the antenna then has a so-called club shape.

The wavelength of the radar is in the range of radio waves in the short to microwave range. A pulse radar sensor sends pulses with a typical duration in the low microsecond range and then waits for echoes. The transit time of the pulse is the time between sending and receiving the echo. It is used to determine distance.

A direction of the scanning beam of a pulse radar sensor can also be effected electronically by phase-controlled antenna arrays instead of by aligning the antenna or antennas. This means that several objects can be targeted quickly and tracked virtually simultaneously.

The radar sensor works with a power of, for example, approx. 10 mW. This performance is so low that there are no health effects. The radar frequency approved for this application is, for example, in the range of 76-77 GHz, corresponding to a wavelength of approximately 4 mm.

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

To detect the position, the spatially resolving sensor, the laser scanner, the safety laser scanner, the 3D camera, the stereo camera or the time-of-flight camera monitors a two-dimensional or three-dimensional protective field or a measurement data contour. This can also be synonymous with a monitoring field.

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

This means that the objects to be detected must be assumed to be less black. For example, a test rod during acceptance. More light reaches the receiver because the object reflects and scatters more light. There is therefore a higher reception energy at the same distance, or the same amount of reception energy at a greater distance.

This results in a higher safe range and therefore a larger protective field. This means, for example, that an autonomous vehicle has a wider field of vision, which enables a higher maximum driving speed and therefore higher productivity.

For example, a 3D camera also monitors a protected area using a large number of recorded distance values. A 3D camera has the advantage that a volume-like protected area can be monitored.

A stereo camera, for example, also monitors a protective area or a protective 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 basic distance from each other. A stereo camera also has the advantage that a volume-like protected area can be monitored.

Using a time-of-flight camera, distance values are determined based on the measured time-of-light, which are determined by an image sensor. A time-of-flight camera also has the advantage that a volume-like or spatial protection area can be monitored.

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

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

A received energy depends squarely on the distance to the object. With reflected light, the light path is “double” because the light is radiated from the transmitter to the object and then back to the receiver. Remission can also be referred to as “detectable degree of remission” or colloquially as reflectivity.

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.

In a further development of the invention, a control and evaluation unit of the light grid is designed to carry out an evaluation based on a larger opening angle of light receivers of the light grid when operating with a reduced safety level.

With a light grid, 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 compared to +/- 2.5° at a higher safety level.

When operating with a larger opening angle, the light curtain is less susceptible to vibrations.

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.

• 1 ein Sicherheitssystem.

The invention is explained below with regard to further advantages and features with reference to the accompanying drawing using exemplary embodiments. The figure of the drawing show in:

• 1 a security system.

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 monitoring 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 monitoring area (10), the radio location system (4) having arranged radio stations (5), with at least one radio transponder (6) on the person (2) and/or the object (8). ) is arranged, wherein position data of the person (2) and / or the object (8) can be determined by means of the radio location system (4), the position data from the radio stations (5) of the radio location system (4) to the control and evaluation unit (3 ) can be transmitted, and status information about the protective field (11) can be determined by means of the spatially resolving sensor (7), whereby status information about the protective field (11) can be transmitted from the spatially resolving sensor (7) to the control and evaluation unit (3), 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) from the radio location system (4) in the surveillance area (10 are determined the control and evaluation unit (3) is designed to have spatial resolution to put the sensor (7) into 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 (10), the control and evaluation unit (3) is designed to put the spatially resolving sensor (7) into operation with a reduced security level.

The solution assumes that in a production plant or a logistics center, in addition to the locally installed spatially resolving sensors (7) or safety sensors, a radio location system (4) or secure localization system is also installed so that the positions of the people present (2), objects ( 8) or by mobile machines with an accuracy of around one meter or more precisely. For this purpose, all people (2), objects (8) and/or mobile machines, for example, are provided with at least one radio transponder (6).

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

The secure radio location system (4) determines and tracks the whereabouts of all people (2) or objects (8) in the surveillance area (10). For example, it causes the spatially resolving sensors (7), which are in the immediate vicinity of people (2) or objects (8), to adopt a higher security level. For example, spatially resolving sensors (7) that are not in the immediate vicinity of people (2) or objects (8) are prompted to adopt a lower security level.

The signals for changing the security level are sent, for example, by the secure radio location 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.

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 to be movable, i.e. mobile. 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 movable manner. For example, the spatially resolving sensor (7) is designed to monitor at least an area of a protective field (11) or protected area.

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

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

In an optoelectronic sensor, for example a light transit time 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 transit time from emission to reception by the person (2) or the object (8) is evaluated, whereby the distance to the person (2) or the object (8) can be determined. This involves positioning, namely the determination of distance and angle, for example.

• Es darf eine höhere minimale Remission von den Objekten (8) angenommen werden. Daraus folgt eine höhere sichere maximale Reichweite des Sensors (7). Damit ist ein größeres Schutzfeld (11) realisierbar. Beispielsweise kann ein autonomes Fahrzeug damit mit einem größeren Schutzfeld (11) realisiert werden. Dadurch kann das autonome Fahrzeug schneller fahren, was wiederum zu einer höheren Produktivität führt.

Downgrading or reducing the security level of the local sensor (7) can have an impact on 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 a larger protective field (11) to be realized. 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.

The different security levels can be switched over by switching the operating mode.

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

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 security level.

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

The information transmission from the radio location system (4) or the control and evaluation unit (3) to the local spatially resolved security sensors (7) can be transmitted in various ways.

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

For example, the information can be transmitted wirelessly directly to the local location-resolving security sensor (7), for example via Bluetooth, Bluetooth low energy, etc.

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

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

The first checking unit or a secure RTLS watchdog controller monitors the control and evaluation unit (3), the first checking unit, for example, checking the plausibility of the specific position data, sending switching signals for a security status of the individual radio transponders (6) or, for example, depending on the situation, checking unit - Reset signals to the radio transponder (6) are initiated.

The first checking 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 two-channel system. The first verification unit provides the necessary diagnostic mechanisms, such as those required by the relevant safety standards.

Reference symbol:

1

security system

2

person

3

Control and evaluation unit

4

Radio location system

5

radio stations

6

Radio transponder

7

spatially resolving sensor

8th

object

9

first verification unit

10

Monitoring area

11

Protective field

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102019131833 A1 [0008]

Claims (13)

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 of the object (8) in the monitoring 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), the protective field being arranged within the monitoring area, wherein the radio location system (4) has arranged radio stations (5), at least one radio transponder (6) being arranged on the person (2) and/or the object (8), wherein position data of the person (2) is obtained by means of the radio location system (4). and/or the object (8) can be determined, 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 about the protective field can be determined by means of the spatially resolving sensor (7). , wherein status information about the protective field can be transmitted from the spatially resolving sensor (7) to the control and evaluation unit (3), characterized in that the control and evaluation unit (3) is designed to receive the position data of the radio location system (4) and the status information of the to evaluate 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, the control and evaluation unit (3) is designed to incorporate the spatially resolving sensor (7). to set an 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 use the spatially resolving sensor ( 7) to move to an operation with a reduced security level. Security system (1). Claim 1 , characterized in that when operating with a reduced safety level, a control and evaluation unit of the spatially resolving sensor is designed to carry out external light tests with a lower quality due to lower requirements with regard to external light resistance. Security system (1) according to one of the preceding claims, characterized in that when operating with a reduced security level, a control and evaluation unit of the spatially resolving sensor is designed, if contamination of a windshield of the spatially resolving sensor is detected, only a warning from the control and The evaluation unit will output, but the switching outputs of the spatially resolving sensor remain active. Security system (1) according to one of the preceding claims, characterized in that when operating with a reduced security level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer error control measures. Security system (1) according to one of the preceding claims, characterized in that when operating with a reduced security level, a control and evaluation unit of the spatially resolving sensor is designed to carry out fewer or no more multiple evaluations. Security system (1) according to one of the preceding claims, characterized in that a first checking unit (9) is provided, the first checking unit (9) being connected to the control and evaluation unit (3), the control and evaluation unit (3 ) is checked by the first checking unit (9). Security system (1) according to one of the preceding claims, characterized in 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 ) is a maximum of 0.5 mW. Security system (1) according to one of the preceding claims, characterized in that the spatially resolving sensor (7) is an ultrasonic sensor or a radar sensor. Security system (1) according to one of the preceding claims, characterized in that the spatially resolving sensor (7) is designed for at least spatial monitoring of a monitoring area Security system (1). Claim 1 , characterized in that the spatially resolving sensor is a laser scanner (14), a security laser scanner, a 3D camera, a stereo camera or a time-of-flight camera. Security system (1) according to one of the preceding claims, characterized in 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 security level. Security system (1). Claim 1 , characterized in that the spatially resolving sensor is a light grid. Security system (1). Claim 12 , characterized in that a control and evaluation unit of the light grid is designed to carry out an evaluation based on a larger opening angle of light receivers of the light grid when operating with a reduced safety level.

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