Safety system and method using a safety system

Abstract

A method using a safety system for localizing at least one object, having at least one control and evaluation unit, having at least one radio location system, wherein the radio location system has at least three arranged radio stations, wherein at least one mobile device having at least one radio transponder is arranged at the object, wherein position data of the radio transponder and thus position data of the objects can be determined by means of the radio location system, wherein the radio transponder has an identification, wherein a respective radio transponder is associated with at least either a person or a mobile object, wherein the control and evaluation unit is configured to distinguish the persons and mobile objects, and wherein a spatially expanded protected volume is formed around the radio transponder.

Claims

1. A safety system for localizing at least one object, the safety system comprising at least one control and evaluation unit, and at least one radio location system, wherein the radio location system has at least three arranged radio stations; wherein at least one mobile device having at least one radio transponder is arranged at the object; wherein position data of the radio transponder and thus position data of the objects 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; and/or the position data can be transmitted from the radio transponder to the control and evaluation unit wherein the control and evaluation unit is configured to cyclically detect the position data of the radio transponder, with the objects being persons or mobile objects, with the radio transponders having identification, with a respective radio transponder being associated with at least either one person or one mobile object, with the control and evaluation unit being configured to distinguish the persons and mobile objects, and with a spatially expanded protected volume being formed around the radio transponder.

2. The safety system in accordance with claim 1, wherein a size and/or a shape of the protected volume is configurable via a configuration device, with a wireless communication link being present between the configuration device and the radio transponder and/or one of the radio stations.

3. The safety system in accordance with claim 1, wherein a shape of the protected volume is rectangular, parallelepiped-shaped, cylindrical, spherical, or oval, or cruciform.

4. The safety system in accordance with claim 1, wherein at least two radio transponders are provided, with the radio transponders each having protected volumes of different sizes.

5. The safety system in accordance with claim 1, wherein the radio transponder has at least one acceleration sensor; and wherein a size and/or a shape of the protected volume can be set in dependence on sensor data of the acceleration sensor.

6. The safety system in accordance with claim 1, wherein the radio transponders can be visually distinguished.

7. The safety system in accordance with claim 1, wherein the size and/or shape of the protected volume of the radio transponder is dependent on the position data of the same radio transponder.

8. The safety system in accordance with claim 1, wherein the size and/or shape of the protected volume of the radio transponder is dependent on the position data of a different adjacent radio transponder.

9. The safety system in accordance with claim 1, wherein the size and/or the shape of the protected volume is changed for a limited time and the previously activated size and/or shape is reestablished after an elapse of the time.

10. The safety system in accordance with claim 1, wherein the safety system has at least one machine arranged as stationary and having a hazard site of the machine, with the position of the hazard site arranged as stationary being known to the control and evaluation unit, and with the machine being able to be influenced in dependence on the position data of the radio transponder.

11. The safety system in accordance with claim 1, wherein the mobile device has a visual display unit and/or an acoustic signal unit and/or a haptic signal unit or is at least wirelessly connected to such a one.

12. The safety system in accordance with claim 1, wherein the control and evaluation unit is configured to respectively determine a position of the radio transponders at different points in time and to determine a speed, an acceleration, a direction of movement and/or at least one path or a trajectory of the radio transponders from it.

13. The safety system in accordance with claim 1, wherein the safety system has a map or a map model; and wherein a navigation of the movable machine takes place in the map or in the map model.

14. The safety system in accordance with claim 1, wherein the mobile device has at least two radio transponders, with the two radio transponders being arranged spaced apart from one another and with the control and evaluation unit being configured to cyclically compare the position data of the radio transponders and to form cyclically checked position data of the objects.

15. The safety system in accordance with claim 1, wherein sequence steps and/or process steps of the machine or plant are read by the control and evaluation unit.

16. The safety system in accordance with claim 1, wherein at least one job planning for the plant and/or target coordinates of the mobile objects are read by the control and evaluation unit.

17. The safety system in accordance with claim 1, wherein the safety system has a database, with the database having data on the dwell probability of the objects and a time and/or space frequency distribution of the objects.

18. The safety system in accordance with claim 1, wherein a degree of productivity of the plant, of the machine, and/or of the objects is detected by means of the control and evaluation unit.

19. The safety system in accordance with claim 1, wherein warnings are output to the persons by means of at least one display unit.

20. The safety system in accordance with claim 1, wherein the control and evaluation unit is configured to control and thus to influence the machine and/or the mobile vehicle.

21. The safety system in accordance with claim 1, wherein plausibility values are formed on the basis of the detected signal strengths of the radio signals of the radio transponders and from the comparison of the position data of the radio transponders.

22. The safety system in accordance with claim 1, wherein the spacings between the radio transponders are known to the control and evaluation unit and are stored in a memory of the control and evaluation unit.

23. The safety system In accordance with claim 1, wherein at least three radio transponders are arranged, with the control and evaluation unit being configured to form orientation data of the object from the position data of the radio transponders

24. The safety system in accordance with claim 1, wherein the radio transponders each have at least one time measurement unit, with the radio stations likewise respectively having at least one time measuring unit, with the radio stations being configured to read and/or describe the times of the time measurement units of the radio transponders and with the radio stations being configured to synchronize the times of the time measurement units of the radio transponders and/or with the radio stations being configured to compare the times of the time measurement units of the radio transponders with the times of the time measurement units of the radio stations.

25. The safety system in accordance with claim 1, wherein the safety system has optical sensors, radar sensors, RFID sensors, and/or ultrasound sensors for localizing and detecting the objects.

26. The safety system in accordance with claim 1, wherein the radio location system is an ultra wideband radio location system, with the frequency used being in the range from 3.1 GHz to 10.6 GHz, with the transmission energy per radio station amounting to a maximum of 0.5 mW.

27. The safety system in accordance with claim 1, wherein a change of the safety function of the safety system takes place on the basis of the checked position data by means of the control and evaluation unit.

28. The safety system in accordance with claim 1, wherein position data checked by means of the control and evaluation unit controller are checked for agreement with stored position data of a safe point of interest.

29. A method using a safety system for localizing at least one object, the safety system having at least one control and evaluation unit, and having at least one radio location system, wherein the radio location system has at least three arranged radio stations; wherein at least one mobile device having at least one radio transponder is arranged at the object; wherein position data of the radio transponder and thus position data of the objects are determined by means of the radio location system; wherein the position data are transmitted from the radio station of the radio location system to the control and evaluation unit, and/or wherein the position data are transmitted from the radio transponder to the control and evaluation unit, wherein the control and evaluation unit is configured to cyclically detect the position data of the radio transponder, with the objects being persons or mobile objects, with the radio transponders having an identification, with a respective radio transponder being associated with at least either one person or one mobile object, with the control and evaluation unit being configured to distinguish the persons and mobile objects, and with a spatially expanded protected volume being formed around the radio transponder.

Description

[0166] The invention will also be explained in the following with respect to further advantages and features with reference to the enclosed drawing and to embodiments. The Figures of the drawing show in:

[0167] FIGS. 1 to 3 and FIGS. 7 and 8 respectively, a safety system for localizing at least two objects;

[0168] FIGS. 4 to 6 respectively, a plurality of radio transponders on an object.

[0169] In the following Figures, identical parts are provided with identical reference numerals.

[0170] FIG. 1 shows a safety system 1 for localizing at least one object 2, having at least one control and evaluation unit 3, having at least one radio location system 4, wherein the radio location system 4 has at least three arranged radio stations 5, wherein at least one mobile device 19 having at least one radio transponder 6 is arranged at the object 2, wherein position data of the radio transponder 6 and thus position data of the objects 2 can be determined by means of the radio location system 4, wherein the position data can be transmitted from the radio station 5 of the radio location system 4 to the control and evaluation unit 3, and/or the position data can be transmitted from the radio transponder 6 to the control and evaluation unit 3, wherein the control and evaluation unit 3 is configured to cyclically detect the position data of the radio transponder 6, wherein the objects 2 are persons 9 or mobile objects 7, wherein the radio transponder 6 has identification, wherein a respective radio transponder 6 is associated with either a person 9 or a mobile object 7, wherein the control and evaluation unit 3 is configured to distinguish the persons 9 and mobile objects 7, and wherein a spatially expanded protected volume 20 is formed around the radio transponder 6.

[0171] The terms protected volume 20 and protected zone 20 are used as synonymous terms in the following.

[0172] The objects 2 are protected over the spatially expanded protected volume 20. If the object 2 comes too close to a hazard site, this is reported to the object 2, for example visually, and the object 2 can move away from the hazard site again.

[0173] In the case of persons 9 as objects 2, the person 9 can approach the hazard site on foot, for example, up to a permitted minimum distance. As soon as the person 9 approaches the minimum distance, the person 9 is visually warned, for example. Provision can simultaneously also be made that the hazard site 9 reacts to the approach of the person 9 and reduces the degree of a possible hazard.

[0174] In the case of mobile objects 7 that are, for example, autonomously driving vehicles, the mobile object 7 can, for example. approach the hazard site while driving, for example, up to a permitted minimum distance. As soon as the mobile object 7 has approached the minimum distance, the mobile object 7 is warned, for example, by means of a command from the control and evaluation unit 3.

[0175] Provision can simultaneously also be made that the hazard site reacts to the approach of the mobile object 7 and reduces the degree of a possible hazard. A plurality of mobile objects 7 can also mutually react, for example by evasive maneuvers and/or braking maneuvers.

[0176] A securing is possible over larger zones by the safety system 1, that is, for example, of a large number of work stations, of a large number of robots, or, for example, even of whole production facilities, since not only a local presence or approach of persons 9 is detected, but rather a position of a large number of persons 9 and mobile objects 7 or mobile machines active in an environment or zone can be detected and can be continuously tracked.

[0177] The localization of the radio transponders 6 takes place by time of flight measurements of radio signals that are cyclically exchanged between the radio transponders 6 and a plurality of fixed position radio stations 5. This triangulation works very well when the signals are transmitted at a sufficient signal strength and on a straight or direct propagation path.

[0178] The movable or mobile object 7 can, for example, be a mobile vehicle 8, a guideless vehicle, a driverless vehicle or autonomous vehicle, an automated guided vehicle, a mobile robot, an industrial mobile robot, or a robot having movable robot arms. The mobile object 7 thus has a drive and can be moved in different directions.

[0179] The person 9 can, for example, be an operator or a service engineer. The radio transponders 6 are arranged on the clothing or on the equipment of the person 8, for example. It can here, for example, be a vest to which the radio transponders 6 are firmly fixed. The radio transponders 6 are arranged, for example, on the shoulders and in the chest and back areas. The radio transponders 6 can, however, also be arranged at different locations on the person 0. Two radio transponders 6 are, for example, arranged on the shoulders of a vest of a person 9.

[0180] FIG. 2 shows two zones A and B that are connected to one another via a passage and that are connected to one another by means of boundaries or walls 11.

[0181] In accordance with FIG. 2, a securing is possible over larger zones A and B, that is, for example, of a large number of work stations, of a large number of robots, or, for example, of whole production facilities, since not only a local presence or approach of persons 9 is detected, but rather a position of a large number of persons 9 and mobile machines 8 active in an environment or zone A, B can be detected and can be continuously tracked. A plurality of radio stations 5 are provided for this purpose, for example.

[0182] In accordance with FIG. 2, the size and shape of the protected volume 20 is configurable via a configuration device, with a wireless communication link being present between the configuration device and the mobile device or the radio transponder 6.

[0183] The size and shape of the protected volume 20 can thus be individually adapted. The required safety standards naturally have to be observed here. The configuration device can be a PC, a portable device, a tablet computer, a smartphone, or similar.

[0184] The wireless communication link can be near field communication, abbreviated to NFC.

[0185] The wireless communication link can, however, also be a radio link in accordance with the Bluetooth standard or in accordance with the Bluetooth low energy standard, abbreviated to BLE.

[0186] In accordance with FIG. 2, the shape of the protected volume 20 is approximately rectangular, parallelepiped-shaped, or oval. Other shapes can, however, also be provided for the protected volume 20.

[0187] In accordance with FIG. 2 at least two radio transponders 6 are provided, with the radio transponders 6 having protected volumes 20 of different sizes.

[0188] A plurality of radio transponders 6 are thereby provided from which a user only has to select the suitable one.

[0189] A time-consuming reprogramming and technical safety acceptance of protected zones by a trained safety engineer is thereby not necessary.

[0190] The person 9 can simply increase the safety for critical work by a larger protected zone 20.

[0191] In accordance with FIG. 2, the mobile device having the radio transponder 6 has at least one acceleration sensor and the size of the protected volume 20 can be set in dependence on sensor data of the acceleration sensor. The acceleration sensor is, for example, evaluated directly on the mobile device having the radio transponder 6 or is evaluated by the control and evaluation unit 3.

[0192] It is thereby possible, for example, that the radio transponder 6 is configurable or settable by a simple shaking by hand. The size and/or shape of the protected volume 20 can thus be set by a simple shake, for example. Such a configuration can also be time limited, for example. So that the original protected volume 20 is automatically activated again after a specific time.

[0193] It is furthermore also possible to act on a hazard site of a machine 14 via an acceleration movement of the mobile device or of the radio transponder 6. It is, for example, possible due to the movement of the radio transponder 6 to slow down or to stop a hazardous movement of a machine 14, for example. A machine 14 can, for example, also be put into a setting mode via the movement of the radio transponder 6.

[0194] To ensure a minimum amount of safety, the protected volume 20 can, for example, not be completely shut down by the counter measure or be cut down to a radius of ZERO. It is, however, always possible to increase the protected volume 20.

[0195] The radio transponders 6 can be visually distinguished in accordance with FIG. 2. Different radio transponders 6 having differently preset protected volumes 20, for example, have different colors, different markings, and/or different symbols. A person 9 who selects the radio transponders 6 for himself, for another person 9, or for the application on a mobile object 7 can thereby determine which radio transponder 6 has which protected volume 20 or which protected volumes 20.

[0196] Red radio transponders, for example, have large protected volumes 20; yellow radio transponders have medium-sized protected volumes 20; and blue radio transponders 6 or green radio transponders 6 have a smaller or a customary normally sized protected volume 20. The radio transponders 6 can be intuitively distinguished via such a color marking.

[0197] The shape of the protected volume 20 can, for example, be recognized in the symbol on the radio transponder so that the suitable radio transponder 6 and thus the suitable protected volume 20 is selected with reference to the symbol.

[0198] In accordance with FIG. 2, the size of the protected volume 20 of the radio transponder 6 is dependent on the position data of the same radio transponder 6.

[0199] The protected zone 20 is, for example, dependent on the vertical location of the radio transponder 6. A height over a floor is, for example, determined directly via the radio location. For example, the height can also be checked via an air pressure sensor integrated in the radio transponder 6 or the accuracy of the height input can be improved.

[0200] The control and evaluation unit 3, for example, compares a measured position or height of the person 9 with an environmental map of the factory facility. The control and evaluation unit 3 can determine the height at which the person 9 is located on the basis, for example, of existing 3D data of the environmental map. The same applies to an object 2 or a mobile object 7, for example an autonomous vehicle, that moves through a factory facility, in particular through a multistory factory facility.

[0201] The protected zone 20 can, for example, be made bigger or smaller when the person 9 is outside a predetermined work zone. E.g. when the person 9 who bears the radio transponder is on a ladder or on a lifting cart or, in another case, works on the ground or even lies flat on the ground.

[0202] A change of the protected zones 20 can thus, for example, be carried out in dependence on a detected height location.

[0203] In accordance with FIG. 2, the size of the protected volume of the radio transponder 6 is dependent on the position data of a different radio transponder 6.

[0204] The protected zone 20 is changed, for example, when two radio transponders 6 fall below a specific minimum spacing for a specific time period. For example, when a person 9 approaches a mobile object 7 or when, for example, two mobile objects 7 move toward one another.

[0205] The control and evaluation unit 3 can, for example, control a path calculation for mobile vehicles 8, with traveled independent individual routes, for example, being combined into convoy groups to provide space for persons 9.

[0206] In accordance with FIG. 2, the size and/or the shape of the protected volume 20 is changed for a limited time and the previously activated size and/or shape is reestablished after an elapse of the time.

[0207] In accordance with FIG. 2, the safety system 1 has at least one machine 14 arranged as stationary and having a hazard site of the machine 14, with the position of the hazard site arranged as stationary being known to the control and evaluation unit 3, with the machine 14 being able to be influenced in dependence on position data of the radio transponder 6.

[0208] The protected zone 20 can, for example, be changed when a person approaches a machine 14 or works on a machine 14, for example.

[0209] In accordance with FIG. 2, the mobile device has a visual display unit and/or an acoustic signal unit and/or a haptic signal unit or is at least wirelessly connected to such a one.

[0210] It can, for example, be displayed via a display on the mobile device having the radio transponder 6 how large the set protected volume 20 is and also, for example, further properties, for example the set duration of the protected zone 20. In the simplest case, display LEDs are arranged on the mobile device or the radio transponder 6 that change their color when the protected zone 20 is changed to indicate the changed protected zone. 20

[0211] The data on the protected zone 20 can also be displayed graphically on an external display of a machine control, for example, or on a mobile device such as a smartphone that receives the data from the radio transponder 6 via the control and evaluation unit 3.

[0212] In accordance with FIG. 7, the control and evaluation unit 3 is configured to respectively determine a position of the radio transponders 6 at different points in time and to determine a speed, an acceleration, a direction of movement and/or a path 12 or a trajectory 12 of the radio transponders 6 from it.

[0213] The speeds and directions of movement of all the persons 9 and mobile objects 7 are preferably taken into account.

[0214] The position information serves for the calculation of probable movement sequences or trajectories 12 of all the objects 2, that is the persons 9 or mobile objects 7.

[0215] A family of movement sequences is determined for each person 9 and for each mobile object 7 with the aid of position information and is provided with a degree of probability, for example. The degree of probability is here estimated, for example, on the basis of the distance covered and/or on the direction of movement. Short direct paths are thus, for example, more probable than long indirect paths. The degree of probability can furthermore be estimated on the basis of a known history of routes of the objects 2. Paths that were used often in the past, for example, are thus more probable than new routes. The degree of probability can furthermore be estimated on the basis of known problems. A disturbed possible route will thus more probably be avoided than a non-disturbed route.

[0216] The most probable path 12, route, or trajectory 12 is selected from a family of possible trajectories 12 and the probabilities associated with them for every person 9 and for every mobile object 7 or for every vehicle.

[0217] In accordance with FIG. 7, the safety system has a map or a map model and a navigation of the movable objects takes place in the map or map model.

[0218] The map model here can also have information on interfering influences such as blocks or congestion information.

[0219] In this respect, the comparison with accessible routes in a floor plan can also serve for the check. For this purpose that region is marked as part of the configuration of the localization system in which mobile machines 7 and persons 9 can dwell at all, in particular walkable or travelable routes. A localization outside these zones will thus signal a systematic measurement error. The degree of plausibility is reduced by the determined inconsistency.

[0220] Additional information can also be made usable here by considering preceding values. The correction of inconsistent position values can therefore take place in the direction of the last valid measurement or in accordance with a trajectory estimate.

[0221] A comparison of radio locations that were determined with the aid of independent or different subsets of the available radio stations 5 or anchor points is furthermore possible

[0222] In accordance with FIG. 2, the mobile device has at least two radio transponders 6, with the two radio transponders 6 being arranged spaced apart from one another and with the control and evaluation unit 3 being configured to cyclically compare the position data of the radio transponders 6 and to form cyclically checked position data of the objects 2.

[0223] In accordance with FIG. 2, position data usable in a technical safety manner are provided. This means that the position data of all persons 9 and objects 7 thus acquired can be used as the basis for a comprehensive, forward-looking, and productivity optimizing securing concept.

[0224] The position information of a large number or of all of the mobile objects 7 or mobile participants is available in real time in an industrial work environment due to the safety system 1.

[0225] Since at least two respective radio transponders 6 are arranged at the respective object 2, errors in the localization information can be avoided since namely the localization information is always available from at least two independent radio transponders 6. The localization and the formed position signal is thus usable in the sense of functional safety. It is thus possible to discover and avoid erroneous localizations and to improve the quality of the spatial information.

[0226] The localization information, position information, or position data present are thus checked with respect to their reliability. A degree of reliability required for the further use can furthermore be associated with the position data.

[0227] The previously customary strategy in accordance with the prior art, according to which a machine 14 is shut down or slowed down on the presence of a person 9 in the hazardous zone, can admittedly also be provided here, but it is also possible to avoid a shutting down or a direct slowing down since more information on the total situation and positions of the objects 2 is present.

[0228] The positions are therefore determined by means of radio location for at least two radio transponders 6 in a spaced apart arrangement and they are compared with the expectation of a known spaced apart arrangement.

[0229] In accordance with FIG. 2, sequence steps and/or process steps of the machine 14 or plant are read by the control and evaluation unit 3.

[0230] Sequence steps and/or process steps planned for the future are thereby known to the control and evaluation unit 3 and can be used for a forward-looking response and thus for a forward-looking influencing of the machine 14 and/or of the mobile objects 7.

[0231] The protected zone 20 can, for example, be reorganized with reference to sequence steps or process steps of a process control. When the mobile object 7 or the person 9 has collected transported goods, the mobile object 7 is given a larger protected zone 20 when the transported goods project beyond the mobile object 7, for example an autonomous vehicle. The information on the collection can e.g. take place by NFC, an inductive proximity sensor, a barcode on the transported goods to the control and evaluation unit 3 via the mobile object 7.

[0232] In accordance with FIG. 2, at least one job planning for the plant and target coordinates of the mobile vehicles 8 are read by the control and evaluation unit 3.

[0233] Sequence steps and/or process steps planned for the future are thereby known to the control and evaluation unit 3 on the basis of the job planning and the target coordinates of the mobile objects 7 or mobile vehicles 8 and can be used for a forward-looking response and thus for a forward-looking influencing of the machine 14 and/or of the mobile objects 7.

[0234] In accordance with FIG. 7, the safety system 1 has a database, with the database having data on the dwell probability of the objects 2 and a time and/or space frequency distribution of the objects 2.

[0235] Statistical information that was derived from the observation of past routines can thereby be generated and evaluated.

[0236] For example, frequently traveled routes and less frequently traveled routes of the mobile objects 7 are known to the control and evaluation unit 3, whereby a possible risk for persons 9 can be estimated better and with a higher probability. A possible risk to persons 9 can be estimated better and with a higher probability due to the known dwell probabilities since, for example, mobile objects or mobile objects 7 or mobile vehicles 8 can travel at higher speeds at points with a small dwell possibility of persons 9 than in zones in which persons 9 will dwell with a high probability.

[0237] In accordance with FIG. 7, a degree of productivity of the plant, of the machine 14, and/or of the objects 2 is detected by means of the control and evaluation unit 3.

[0238] In accordance with FIG. 3, warnings are output to the persons by means of at least one display unit 18.

[0239] An improved system state is achieved by warnings or instructions by means of the display unit 18.

[0240] It can thus be dynamically displayed, for example, for a zone by means of a display unit 18 whether a presence of persons 9 in this zone A, B is allowed or not. Routes recommended for persons 9 can furthermore be displayed or a warning against non-recommended routes can be indicated by means of the display unit 18, for example.

[0241] In accordance with FIG. 3, the control and evaluation unit 3 is configured to control and thus to influence the machine 14 and/or the mobile vehicle 8.

[0242] The effectiveness of the different effects and their influence on productivity differ here and are used for a prioritization of the measures. It must, for example, be anticipated that a warning to a person 9 or the instruction to take an alternative route is ignored by persons 9. On a directly impending risk, use is therefore made of the very much more reliable controls of the machines 14, e.g. a slowing down of the machine 14 or an emergency stop of the machine 14.

[0243] An evaluation is here made at every point in time from the observation of the time development of the safety system 1 whether the safety system 1 is optimized and whether the constraints according to which a risk can be tolerated are observed. This evaluation enters as feedback into the selection of the control measures.

[0244] The following possibilities are provided for the influencing, for example: [0245] an emergency stop of a machine 14 or of a mobile object 7 or vehicle; [0246] a slowing down of a machine 14 or of a mobile object 7 or vehicle; [0247] a change of a path plan of a person or of a mobile object or vehicle [0248] a change of an order of individual process steps of an automation routine; [0249] warnings to a person 9; [0250] instructions to a person 9, e.g. indications of an alternative travel path.

[0251] In accordance with FIG. 3, plausibility values are formed on the basis of the detected signal strengths of the radio signals of the radio transponders 6 and from the comparison of the position data of the radio transponders 6.

[0252] The position information of a large number or of all of the mobile objects 7 or mobile participants is thus available in real time in an industrial work environment.

[0253] In accordance with FIG. 3, the spacings between the radio transponders 6 are known to the control and evaluation unit 3 and are stored in a memory 10 of the control and evaluation unit 3.

[0254] In accordance with FIG. 3, at least three radio transponders 6 are arranged, with the control and evaluation unit 3 being configured to form orientation data of the object 2 from the position data of the radio transponders 6.

[0255] Two radio transponders 6 are, for example, arranged on the shoulders of a vest of a person 9. A further radio transponder 6 is, for example, arranged on a helmet of the person 9.

[0256] In accordance with FIG. 4 at least four, in accordance with FIG. 5 at least six, or in accordance with FIG. 6 at least eight radio transponders 6 are arranged on the object, with two respective radio transponders 6 each lying on a straight line, with the straight lines each being perpendicular to one another.

[0257] Radio transponders 6 are thereby respectively arranged in pairs, with the respective pairs each having a different orientation. An orientation from every direction is thereby unique. Furthermore, a radio transponder 6 can also be arranged at the point of intersection of the straight lines so that a single radio transponder 6 forms a center or a central position point that can be used as a reference position.

[0258] In accordance with FIG. 3, the radio transponders 6 each have at least one time measurement unit, with the radio stations 5 likewise respectively having at least one time measuring unit, with the radio stations 5 being configured to read and describe the times of the time measurement units of the radio transponders 6 and with the radio stations 5 being configured to synchronize the times of the time measurement units of the radio transponders 6 and to compare the times of the time measurement units of the radio transponders 6 with the times of the time measurement units of the radio stations 5.

[0259] In accordance with FIG. 8, the safety system 1 has optical sensors 13, radar sensors, RFID sensors, and/or ultrasound sensors for the localization and detection of the objects 2.

[0260] The position data or position information can be compared with safe or unsafe position data or position information that were/was detected at spots at specific locations in the operating environment with the aid of optical sensors 13, radar sensors, RFID sensors and/or ultrasound sensors.

[0261] The plausibility of a position value is therefore the greater, the better the agreement between the optical position determination and the radio location and the less ambiguous the association between the optical position determination and the radio location is also possible.

[0262] In accordance with FIG. 2, the radio location system 4 is an ultrawide band radio location system, with the frequency used being in the range from 3.1 GHz to 10.6 GHz, with the transmission energy amounting to a maximum of 0.5 mW per radio station.

[0263] A plurality of radio stations 5, for example more than three, are preferably arranged that monitor at least some of the movement zone of the person 9 or object 2.

[0264] In accordance with FIG. 2, a change of the safety function of the safety system 1 takes place on the basis of the checked position data by means of the control and evaluation unit 3.

[0265] A change of the safety function of the safety function of the safety system 1 takes place on the basis of position data by means of the control and evaluation unit 3.

[0266] If a predetermined position has been recognized that is stored, for example, the control and evaluation unit 3 can switch over to a different protective measure or safety function. The switching over of the protective measure can comprise, for example, a switching over of measured data contours, a switching over of protected zones 20, a size or shape matching of measured data contours or protected zones 20, and/or a switching over of the properties of a protected zone 20.

[0267] In accordance with FIG. 2, position data checked by means of the control and evaluation unit 3 are checked for agreement with stored position data of a safe point of interest.

[0268] A check of the radio location can optionally additionally be carried out at specific monitoring points that, for example, deliver both optically determined position information and position information detected by radio location in the sense that a check is made as to whether a radio location has taken place at all for a detected object 2. Such a confirmation can reveal the safety critical error cases of a missing or non-functioning tag and can satisfy the demands on a cyclic test in the sensor of the standard ISO 13849-1.

[0269] The comparison with independent position data can also take place at known interaction points. For example, by actuation of a switch or on a monitored passage through a door. At this moment, the position of the person 9 is very precisely known and can be used for a validation of the position data or of the position information. A corresponding process is also possible with autonomous vehicles. The position is very accurately known on docking at a charge station or on the arrival at transfer stations and can be used for checking the radio location and technical safety error control.

REFERENCE NUMERALS

[0270] 1 safety system [0271] 2 object [0272] 3 control and evaluation unit [0273] 4 radio location system [0274] 5 radio stations [0275] 6 radio transponder [0276] 7 mobile objects [0277] 8 mobile vehicles [0278] 9 person [0279] 10 memory [0280] 11 wall/boundary [0281] 12 path/trajectory [0282] 13 optical sensor [0283] 14 machine [0284] 18 display unit [0285] 19 mobile device [0286] 20 protected volume/protected zone [0287] A zone [0288] B zone