Method and apparatus for detection, transmission and processing of safety-related signals

• US 6,711,713 B1
• Filed: 05/03/2000
• Issued: 03/23/2004
• Est. Priority Date: 05/03/1999
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Rumpler, Gerhard, Kahle-Nobis, Gerhard, Meier, Christof
• Primary Examiner(s): Baker, Stephen M.
• Application Number:
  US09/564,596
• Time in Patent Office: 1,420 Days
• Field of Search: 714/819, 714/820, 714/821, 700/21
• US Class Current: 714/820
• CPC Class Codes: G05B 19/406 characterised by monitoring or safety G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/33192 Radio link, wireless
• CPC Class Codes: G05B 2219/33235 Redundant communication channels, processors and signal processing hardware
• CPC Class Codes: G05B 2219/50198 Emergency stop
• CPC Class Codes: G08B 29/16 Security signalling or alarm systems, e.g. redundant systems
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability

Abstract

The use of radio technology for transmission of EMERGENCY-OFF, START-, STOP- and process and confirmation signals from industrial processing machines, such as numerically controlled machine tools and robots, by radio is described. There is no need for any additional safety measures for the START and process signals by means of a confirmation signal, provided the control functions satisfy appropriate safety requirements. To this end, safety-relevant signals are physically detected on at least two channels at the transmitter end, the detected data are logically transmitted by at least two channels using a safety technique by radio to a receiver end, and the received data are likewise physically processed and monitored on at least two channels at the receiver end. In addition to the safety-related signal data, additional protection data are produced for monitoring purposes and are used at the receiver end for monitoring by checking the plausibility of a redundant value for data protection and by cross-comparison of the evaluation results, etc.

Claims

1. A method for detection, transmission and processing of safety-related signals using at least one detection unit, a transmission path and a signal processor, comprising:

detecting safety-relevant signals on at least two physical channels at a transmitter end, the safety-relevant signals including signal data, the safety-relevant signal including redundant signals;

transmitting the detected signal data by radio on at least two logical channels to a receiver end using a safety technique;

processing and monitoring the received signal data on at least two physical channels at the receiver end;

producing the redundant signals using at least duplicated electromechanical or electronic input elements; and

producing additional protection data by each detection unit from the signal data for monitoring purposes, the protection data allowing monitoring for at least one of;

i) incorrect transmitters or incorrect receivers, ii) adulteration of the safety-relevant data, iii) loss of data, and iv) repetition of data.

2. The method according to claim 1, wherein the transmitting step includes transmitting the signal data using a digital technique, the digital technique including

cyclically detecting the signal data and the protection data,

forming a data packet from the signal data and the protection data of the at least two physical channels at the transmitter end, the data packet including an added redundant value for data protection, and

transmitting the data packet by radio to the receiver end.

3. The method according to claim 2, further comprising:

providing at the transmitter a counter value;

incrementing or decrementing the counter value for each data packet to be transmitted;

for each data packet, forming the data protection using the signal data, the protection data and the counter value.

4. The method according to claim 2, further comprising:

at the transmitter, separating each data packet into an implicit data element and an explicit data element, the implicit data element including data known at the receiver end; and

transmitting only the explicit data element of each data packet by radio in order to minimize a volume of data to be transmitted; and

at the receiver end, reconstructing the data packet from the known data and the received explicit element.

5. The method according to claim 2, further comprising:

setting up a safe radio data link with the receiver registering with the transmitter, including

uniquely defining communication addresses for the transmitter and the receiver end for each of the at least two channels,

providing a radio link between the transmitter and the receiver end,

transmitting the communication address to the receiver in the form of a data packet, and

terminating the registration process if one of;

i) a predetermined time window is exceeded, ii) any loss or repetition of data occurs, iii) a cross-comparison leads to detection of a fault or error, and iv) the redundant value for data protection (CRC) is identified as not being plausible.

6. The method according to claim 2, for each received data packet, the receiver end performs the steps of:

separating the signal data and protection data from each of the at least two channels at the transmitter end for each of the at least two channels at the receiver end;

performing a plausibility check of the redundant value for data protection for form evaluation results;

comparing the evaluation results in each respective one of the at least two channels at the receiver end; and

if the evaluation is correct, passing the signal data and protection data for the respective channel to an associated signal processor for processing of the safety-relevant data and for monitoring purposes.

7. The method according to claim 6, further comprising:

at the receiver end and in each of the at least two channels at the receiver end, monitoring the received signal data and protection data for at least one of;

i) incorrect transmitters or incorrect receivers, ii) adulteration of the safety-relevant data, iii) loss of data, iv) repetition of data, v) interruption of transmission.

8. A method for detection, transmission and processing of safety-related signals using at least one detection unit, a transmission path and a signal processor, comprising:

detecting safety-relevant signals on at least two physical channels at a transmitter end, the safety-relevant signals including signal data;

transmitting the detected signal data by radio on at least two logical channels to a receiver end using a safety technique;

processing and monitoring the received signal data on at least two physical channels at the receiver end; and

in each of the at least two physical channels at the transmitter, monitoring serviceability of emergency-off or stop-input units and associated operation of the detection units by a positive dynamic activation arrangement.

9. A method for detection, transmission and processing of safety-related signals using at least one detection unit, a transmission path and a signal processor, comprising:

detecting safety-relevant signals on at least two physical channels at a transmitter end, the safety-relevant signals including signal data;

transmitting the detected signal data by radio on at least two logical channels to a receiver end using a safety technique; and

processing and monitoring the received signal data on at least two physical channels at the receiver end

wherein the safety-relevant signals include at least one of;

i) emergency-off signals, ii) emergency-stop signals, iii) signals which initiate movement, and iv) confirmation signals, the safety relevant signals being provided for control purposes in industrial automation.

10. An apparatus for detection, transmission and processing of safety-related signals, comprising:

at least one detection arrangement with at least two physical channels, the at least one detection arrangement being disposed at a transmitter end;

a radio transmission path having at least two logical channels, the radio path using a safe technology, the radio transmission path including a radio module at the transmitter end and a radio module at a receiver end;

a signal processor arrangement disposed at the receiver end, the signal processor arrangement having at least two physical channels; and

duplicated electromechanical, electrical or electronic input element for producing redundant signals;

wherein the detection arrangement produces additional protection data from the redundant signals for monitoring purposes, the additional protection data allowing monitoring for at least one of;

i) incorrect transmitters or incorrect receivers, ii) adulteration of the safety-relevant data in the safety-related signals, iii) loss of data, and iv) repetition of data.

11. The apparatus according to claim 10, wherein the radio transmission is carried out using a digital technique, and wherein the detection arrangement cyclically detects the safety-relevant data and the protection data, and wherein the apparatus further comprises:

a transmission module forming a data packet from the safety-relevant data and the protection data of the at least two physical channels at the transmitter end, a redundant value being added to the data packet for data protection (CRC), the data packet being transmitted to the receiver end via the radio transmission path.

12. The apparatus according to claim 11, wherein the transmitter end provides a counter value which is incremented or decremented for each data packet to be transmitted, the redundant value for data protection being formed from the safety-relevant data, the protection data and the counter value.

13. The apparatus according to claim 11, the receiver end includes at least two receiver modules, the at least two receiver modules separating the safety-relevant data and the protection data, checking the plausibility of the redundant value for data protection to form evaluation results, comparing the evaluation results in each of the at least two physical channels at the receiver end, and, if the evaluation results are correct, passing the received signal data and the protection data for each of the at least two physical channels at the receiver end to an associated signal processor of the associated signal processor arrangement for processing of the safety-relevant data and for monitoring purposes.

14. The apparatus according to claim 13, wherein

the transmission module is configured to separate each data packet into an implicit data element and an explicit data element, the implicit data element including data known at the receiver end, only the explicit element of the data packet being transmitted by radio to minimize a volume of data to be transmitted, at least one of the receiver modules reconstructing the data packet from the known data and the received explicit element.

15. The apparatus according to claim 13, further comprising:

a monitor arrangement provided at the receiver end, the monitor arrangement monitoring the received safety-relevant data and the protection data in each of the at least two physical channels for at least one of;

i) incorrect transmitters or incorrect receivers, ii) adulteration of the safety-relevant data, iii) loss of data, iv) repetition of data, and v) interruption of transmission.

16. The apparatus according to claim 15, wherein the at least two receiver modules include the monitor arrangement.

17. An apparatus for detection, transmission and processing of safety-related signals, comprising:

at least one detection arrangement with at least two physical channels, the at least one detection arrangement being disposed at a transmitter end;

a radio transmission path having at least two logical channels, the radio path using a safe technology, the radio transmission path including a radio module at the transmitter end and a radio module at a receiver end;

a signal processor arrangement disposed at the receiver end, the signal processor arrangement having at least two physical channels; and

a positive dynamic activation arrangement monitoring, in each of the at least two channels in the transmitter end, a serviceability of emergency-off or stop-input units and an associated operation of the detection units.

18. An industrial processing system, comprising:

an arrangement for detection, transmission and Processing of safety-related signals, the arrangement comprising;

at least one detection arrangement with at least two physical channels, the at least one detection, arrangement being disposed at a transmitter end,

a radio transmission path having at least two logical channels, the radio path using a safe technology, the radio transmission path including a radio module at the transmitter end and a radio module at a receiver end, and

a signal processor arrangement disposed at the receiver end, the signal processor arrangement having at least two physical channels; and

a numerically controlled machine tool controlled as a function of the safety-related signals.

19. An industrial processing system, comprising:

an arrangement for detection, transmission and processing of safety-related signals, the arrangement comprising;

at least one detection arrangement with at least two physical channels, the at least one detection, arrangement being disposed at a transmitter end,

a radio transmission path having at least two logical channels, the radio path using a safe technology, the radio transmission path including a radio module at the transmitter end and a radio module at a receiver end, and

a signal processor arrangement disposed at the receiver end, the signal processor arrangement having at least two physical channels; and

a robot controlled as a function of the safety-related signals.