Safety system and method for localizing a person or object in a monitored zone using a safety system

Abstract

A method of localizing a person or object in a monitored zone using a safety system, having a movable machine, having a control and evaluation unit, having at least one radio location system, and having at least one spatially resolving sensor for the position determination of the person or object, wherein the radio location system has arranged radio stations, wherein at least one radio transponder is arranged at the person or object, wherein position data of the person or object can be determined by means of the radio location system, and wherein the position data are transmitted from the radio stations of the radio location system to the control and evaluation unit and position data of the person or object are determined by means of the spatially resolving sensor, wherein the control and evaluation unit compares the position data of the radio location system and the position data of the spatially resolving sensor and forms tested position data on an agreement.

Claims

1. A safety system for localizing at least one person or at least one object in a monitored zone, the safety system comprising: at least one movable machine, a control and evaluation unit, at least one radio location system, and at least one spatially resolving sensor for the position determination of the person or object, wherein the radio location system has arranged radio stations; wherein at least one radio transponder is arranged at the person or object; wherein position data of the person or of 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 position data of the person or of the object can be determined by means of the spatially resolving sensor, and wherein the control and evaluation unit is configured to compare the position data of the radio location system and the position data of the sensor and to form checked position data on an agreement.

2. The safety system in accordance with claim 1, wherein the control and evaluation unit is configured to compare the position data of the radio location system and the position data of the sensor and, on agreement, to permit the person or the object having the radio transponder in a protected field of the spatially resolving sensor and not to output any object determination signal, whereby the movable machine is in an active state.

3. The safety system in accordance with claim 1, wherein the spatially resolving sensor and the radio stations are arranged as stationary or are arranged as mobile at a movable machine.

4. The safety system in accordance with claim 1, wherein checked position data are formed on the basis of the position data of the radio location system and the position data of the sensor, with the control and evaluation unit being configured to compare the checked position data with reference data and on an agreement a change of the safety function of the safety system taking place by means of the control and evaluation unit, with the actuator being operated in a non-dangerous operating mode.

5. The safety system in accordance with claim 1, wherein the control and evaluation unit is configured to set a changed safety function on the basis of the checked position data of the control and evaluation unit, with a movement of the movable machine being changed or influenced by the control and evaluation unit in dependence on the distance of the person from the movable machine.

6. The safety system in accordance with claim 1, wherein the radio location system 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.

7. The safety system in accordance with claim 1, wherein the spatially resolving sensor is an optoelectronic sensor, an ultrasonic sensor, or a radio sensor.

8. The safety system in accordance with claim 1, wherein the spatially resolving sensor is configured for an at least areal monitoring of a monitored zone.

9. The safety system in accordance with claim 1, wherein the spatially resolving sensor is configured for an least spatial monitoring of a monitored zone.

10. The safety system in accordance with claim 1, wherein the optoelectronic sensor is one of a laser scanner, a safety laser scanner, a 3D camera, a stereo camera, and a time of flight camera.

11. A method of localizing a person or object in a monitored zone using a safety system, the safety system comprising at least one movable machine, a control and evaluation unit, at least one radio location system, and at least one spatially resolving sensor for the position determination of the person or object, wherein the radio location system has arranged radio stations; wherein at least one radio transponder is arranged at the person or object; wherein position data of the person or of 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 position data of the of the person or of the object are determined by means of the spatially resolving sensor, characterized in that the control and evaluation unit compares the position data of the radio location system and the position data of the sensor and forms checked position data on an agreement.

Description

[0077] 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:

[0078] FIGS. 1 and 2 respectively, a safety system in a schematic representation;

[0079] FIG. 3 a safety system in a block diagram

[0080] In the following Figures, identical parts are provided with identical reference numerals.

[0081] FIG. 1 shows a safety system 1 for localizing a person 2 or object 8 in a monitored zone having a movable machine 11, having a control and evaluation unit 3, having at least one radio location system 4, and having at least one spatially resolving sensor 7 for the position determination of the person 2 or object 8, wherein the radio location system 4 has arranged radio stations 5, wherein at least one radio transponder 6 is arranged at the person 2 or object 8, wherein position data of the person 2 or object 8 can be determined by means of the radio location system 4, and 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 position data of the person 2 or object 8 can be determined by means of the spatially resolving sensor 7, and the control and evaluation unit 3 is configured to compare the position data of the radio location system 4 and the position data of the spatially resolving sensor 7 and to form checked position data on an agreement.

[0082] Optionally, in accordance with FIG. 2, the control and evaluation unit 3 is configured to compare the position data of the radio location system 4 and the position data of the spatially resolving sensor 7 and, on agreement, to permit the person 2 or the object 8 having the radio transponder 6 in a protected field 13 of the spatially resolving sensor 7 and not to output any object determination signal, whereby the movable machine 11 is in an active state.

[0083] FIG. 3 shows a block structure with the different signals. In accordance with FIG. 3, a classical safety function having a presence detection by the spatially resolving sensor 7 and a safety directed shutdown 16 is complemented by a safe position determination. The laser scanner 10 in accordance with FIG. 3 and FIG. 2 monitors a two-dimensional monitored zone or a measured data contour 14 for the position detection. It can synonymously be a monitored field. The classical safety function by the spatially resolving sensor 7 here serves as a fallback function that steps in if the safe positioning fails. If, however, the position of an object or person was able to be detected with the required safety engineering reliability in the protected field 13, the classical safety function is muted by means of a muting signal 15 and a machine control 12 can optionally make use of safe or checked position data 17 of the object 8 or person 2 for the situation based safeguarding of the movable machine 11.

[0084] In accordance with FIG. 1, the spatially resolving sensor 7 that is used in a stationary manner to safeguard the movable machine 11 or the actuator, additionally provides measured data to enable a positioning of the person 2 or object 8 in the protected field 13. In this way, on the presence of the position data of the radio location system 4 and the position data of the spatially resolving sensor, 7 a validation of the position of the person 2 or object 8 is made possible and thus accessible to a safety engineering use of the position information.

[0085] In addition to this redundant and diverse sensor structure, the error case must also be checked for the safety engineering usability that the position data of the radio location system 4 or the position data of the spatially resolving sensor 7 do not agree with the position data of the radio location system 4.

[0086] In accordance with FIG. 1, a validation dependent bridging or muting of the safety function of the primary safety function, that is the protected field monitoring by the spatially resolving sensor 7 is therefore provided, according to which on an agreement of the position data of the spatially resolving sensor 7 and of the radio location system 4, the person 2 or object 8 having the radio transponder is to be permitted in a protected field of the spatially resolving sensor and no object detection signal is to be output, whereby the movable machine 11 or the actuator is in an active state.

[0087] It is decisive in this process that the primary safety function remains muted for so long as the validation of the position data of the radio location system 4 and the position data of the spatially resolving sensor 7 is successful.

[0088] The validation of the two independent position data or pieces of position information is carried out by the control and evaluation unit 3. The control and evaluation unit 3 is optionally a functionally safe control and evaluation unit 3. The control and evaluation unit 3 has means for error localization, for example. These means are, for example, means for testing, for example a redundant and/or diverse structure having two channels for a mutual check of the determined results and the position data.

[0089] In accordance with FIG. 1, the spatially resolving sensor 7 and the radio stations 5 are arranged as stationary. It is thus a stationary application, wherein the movable machine 11 is, for example, a robot, a handling machine, or the like. The movable machine 11 can also be a processing machine, for example a press or a punching machine, that can likewise be in direct interaction with a person 2 or object 8.

[0090] In accordance with an embodiment, not shown, the spatially resolving sensor and the radio stations are arranged as mobile at a movable machine. It is thus a mobile application, wherein the movable machine is, for example, a vehicle, in particular a driverless vehicle, or the like. The vehicle can likewise be in direct interaction with a person or object.

[0091] In accordance with FIG. 1, checked position data are formed on the basis of the position data of the radio location system 4 and the position data of the spatially resolving sensor 7, with the control and evaluation unit 3 being configured to compare the checked position data with reference data and on an agreement a change of the safety function of the safety system 1 taking place by means of the control and evaluation unit, with the movable machine 11 or the actuator being operated in a non-dangerous operating mode.

[0092] In accordance with FIG. 1, a safe collaboration between the movable machine 11 or the actuator and the person 2 can be implemented. Depending on the position, speed, direction of movement, and/or the distance of the person 2, the movable machine 11 or the actuator is braked, stopped, diverted, and/or accelerated again.

[0093] The movable machine 11 is in particular operated in a non-dangerous operating mode when the person 2 or object 8 is located in a dangerous zone of the movable machine 11.

[0094] Safety critical error cases such as the loss of the radio signal, e.g. because no radio transponder 6 is present, because an energy supply of the radio transponder 6 has failed, or because, for example, the radio transponder 6 is screened, or an erroneous localization of the person 2 or object 8 by the spatially resolving sensor 7, or the defective processing of position data by the control and evaluation unit, 3 result in a safety directed shutting down by the primary safety function, namely by the control and evaluation unit 3, if no valid position data from the spatially resolving sensor 7 are present.

[0095] In accordance with FIG. 2, the radio location system 4 is optionally 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.

[0096] At a minimum only one single radio transponder 6 has to be arranged at the person 2 or object 8, said radio transponder 6 being detected by at least three radio stations 5 arranged as stationary, with the spacing of the radio stations 5 being known.

[0097] 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 2 or object 8.

[0098] At least two or more radio transponders 6 can also be arranged at the person 2 or object 8. The position of the person 2 or object 8 can thereby be identified more exactly and the alignment of the person 2 or object 8 in the stationary state can also be detected when the arrangement of the radio transponders 6 at the person 2 or object 8 is known.

[0099] In accordance with FIG. 1, the spatially resolving sensor 7 is an optoelectronic sensor, an ultrasound sensor, or a radar sensor.

[0100] With a time of flight sensor as the optoelectronic sensor, the light that is transmitted by a light transmitter and that is remitted by the person 2 or object 8 is received by a light receiver and the time of flight from the transmission up to the reception by the person or object 8 is evaluated, whereby the distance from the person 2 or object 8 can be determined.

[0101] The spatially resolving sensor 7 can, however, also be an ultrasound sensor or a radar sensor.

[0102] In accordance with FIG. 1, the spatially resolving sensor 7 is configured for the at least areal monitoring of a monitored zone.

[0103] The spatially resolving sensor 7 for the at least areal monitoring of a monitored zone is a sensor for distance measurement. The distance sensor delivers distance values in at least two-dimensional space. In so doing, the spatially resolving sensor 7 outputs measured values with distance indications and angle indications. For example, the distance is determined by means of time of flight methods or triangulation methods.

[0104] In accordance with an embodiment that is not shown, the spatially resolving sensor is configured for the at least spatial monitoring of a monitored zone.

[0105] In accordance with FIG. 1, the optoelectronic sensor can be a laser scanner 10 or a safety laser scanner.

[0106] In accordance with an embodiment that is not shown, the spatially resolving sensor is a 3D camera, a stereo camera, or a time of flight camera.

REFERENCE NUMERALS

[0107] 1 safety system [0108] 2 person [0109] 3 control and evaluation unit [0110] 4 radio location system [0111] 5 radio stations [0112] 6 radio transponder [0113] 7 spatially resolving sensor [0114] 8 object [0115] 10 laser scanner [0116] 11 movable machine [0117] 12 machine control [0118] 13 protected field [0119] 14 measured contour [0120] 15 muting signal [0121] 16 safety directed shutdown [0122] 17 safe or checked position data