JP5118563B2 - Safety device and method of transmitting security data - Google Patents

Description

  According to a first aspect, the invention relates to a safety device for a device to be protected according to the preamble of claim 1.

  In another aspect, the present invention relates to a security data communication method according to claim 8.

  A general safety device that is particularly suitable for an automatic storage shelf system has first a stationary device with a detector for receiving data. A portable device is also provided, and the portable device is disposed in the device to be protected and has an operation unit that controls the device to be protected to a safe state. In order to operate the operating unit based on the security data, the operating unit is operatively connected to the detecting unit.

  In a general method, security data is received by a stationary detection unit, and security data is transmitted to a portable operation unit mounted on a device to be protected. The operation unit is activated based on the transmitted security data. When the operation unit is specific security data, the device to be protected is controlled to a safe state by the operation unit.

In industry, especially in storage and transport technology, there is often a desire to remotely control a vehicle from a fixed point. This remote control is performed with the assistance of a data radio facility or using a data write barrier. In order to be able to stop such a vehicle when a dangerous state occurs, a facility as described above is provided with a safety device having the following components.
A stationary detector that can be configured as an emergency switch or a security light barrier.
An operating unit that is connected to the vehicle and stops or restores the driving of the vehicle when the detection unit of the safety device is operated;
-A trailing cable that connects a stationary safety device to a portable safety device.

  The state of the detection unit of the safety device is transmitted to the operation unit via the trailing cable, and the operation unit stops or restores the driving of the vehicle depending on the state.

  The use of trailing cables is an expensive technical solution that is prone to failure.

  EP 14533334 A2 and DE 199 20 299 A1 relate to methods and devices for detecting, transmitting and processing signals relating to safety.

  DE102005048386A1 relates to a wireless control device for work equipment.

EP 1453334 German Patent Application No. 19920299 German Patent Application No. 102005048386

  The object of the present invention is to provide a safety device and a method of transmitting security data, which device and method can be handled in an uncomplicated manner, especially in an industrial environment. This solution must also be reliable and inexpensive to operate.

  In a first aspect of the invention, the above object is achieved by a safety device having the features of claim 1.

  In yet another aspect of the invention, the above object is achieved by a method having the features of claim 8.

  Advantageous developments of the invention are described in the dependent claims.

  A safety device of the type described above is also developed progressively as follows. The stationary device has a transmitter that wirelessly transmits security data, and the portable device has a receiver that wirelessly receives security data. In addition, an error prevention encoder connected to the transmitter and the detection unit is provided to encode the transmitted security data, and an error prevention decoder connected to the receiver and the operation unit is provided to receive the received security data. Decrypt the data.

  A method of the type described above is further developed progressively as follows. The security data is transmitted from the detection unit to the operation unit in a wireless manner, and the security data is encoded by an error prevention encoder before the transmission, and is decoded by the error prevention decoder after the transmission.

  The basic concept of the present invention is that instead of using a trailing cable that is complicated to handle and sensitive to disturbances in a safety device that transmits security data, e.g. A wireless connection for transmitting data is constructed and used. This provides a great advantage during actual operation. The above-described solution according to the present invention requires very little maintenance costs and can be realized with low costs.

  It is still another basic concept of the present invention to encode and transmit security data using an error prevention method. In such a system, necessary transmission security can be guaranteed.

  The present invention has the important advantage that as a result of wireless communication, the structure is significantly simplified and the safety is not compromised.

  Another advantage is that, for the purpose of radio transmission, in principle, components that are already known or that are assumed to already exist can be used.

  The advantages of the present invention are particularly prominent when the portable device is configured to be mounted on at least one of a vehicle, an elevating mechanism, and another transport mechanism in an automatic storage shelf system. .

  The detection unit can include a random switching element and a measurement element. For example, the detection unit may include at least one of an emergency stop switch, a light barrier, an optical probe or an optical key switch, a proximity switch, and other sensors.

  In a particularly preferred embodiment of the present invention, the error prevention encoder associates a serial data string with each state of the detector. This data string can be transmitted to the error prevention decoder using a transmitter and a receiver. The error prevention decoder compares the received serial data string with the preset data string stored in the decoder, and the operation unit is driven according to the comparison result. By comparing the received data string with different preset information, the decoder can set different states of the detector of the safety device. As a result, safe coding can be realized without requiring a large amount of cost for the apparatus.

  From a method point of view, this can be achieved in a non-complicated manner, for example by organizing the data sequence in bytes. Controlling the operating part to a safe state, or a quicker switch-off reaction can be realized, for example, by receiving a specific byte, for example a zero byte, that controls the operating part of the safety device.

  In a simple variant of the safety device according to the invention, the error prevention decoder comprises a comparator and a data memory, depending on the purpose described above.

  In the task of discovering the absence of switching information, the decoder can be assigned a time interval, which is the period during which the decoder should have received any information. If no information is present within this period, the decoder controls the operating part of the safety device to a safe state.

  As a result, the operation safety of the device to be monitored is controlled by controlling the operation unit to a safe state when the decoder has a time measurement device and a data string is not received within a predetermined time interval. Further improvement.

  In principle, the transmitter and the receiver may be independent and separate components. However, it is preferable to utilize existing facilities. For example, both the transmitter and receiver may each be part of a data write barrier or data radio facility. Such a modification is particularly preferred because, for example, in the case of an automatic storage shelf system, a data write barrier or a data radio facility often already exists.

  In order to be able to more easily sort the data of the detector of the safety device and the other data to be transmitted, the security data is appropriately transmitted on a transmission medium in a separate channel. Therefore, if both the transmitter and the receiver are configured to support multi-channel data transmission, the functionality of the apparatus of the present invention can be further improved. In order to improve the safety of the method and apparatus of the present invention, for example, in order to clearly distinguish emergency switch-off data from other data transmitted, emergency switch-off data is frequency shifted keying modulation ( FSK) is transmitted on a separate data channel.

  As a result of the comparison described above, the decoder can also detect signal corruption. If signal corruption is found, the decoder may decide to control the operating part of the safety device to a safe state. The feature of this modification is that safety is particularly high.

  In a complex industrial environment, there are so many failures and disturbances that you do not want the monitored device to be set to a safe state for each possible minor failure Is often required. Such a situation will result in excessive damage and downtime.

  In general, the maximum allowable error rate or damage rate can be defined, within which the decoder will tolerate transmission errors, and if the range is exceeded, the decoder will put the operating part of the safety device in a safe state. Control. In a particularly preferred variant of the method according to the invention, the error prevention decoder identifies the error rate when comparing the received data sequence with the stored preset data sequence, and the decoder is allowed. Save the error rate limit value. The operating unit is controlled to a safe state if the above-mentioned limit value is exceeded with respect to the allowable error rate. This safe state may in particular be a dangerous movement stop.

  Further advantages and features of the invention can be inferred from the attached drawings.

  In the embodiment of the safety device 20 of the present invention shown in FIG. 1, the emergency switch 1 and the activation recovery key switch 2 together form a detection unit, which is connected to the error prevention encoder 4.

  The error prevention decoder 4 generates the serial signal 5 by associating the states of the emergency switch 1 and the activation recovery key switch 2 to which the characteristics are given by the signals 30 and 32 with the serial bit string.

  The error prevention encoder 4 is connected to a data write barrier transmitter 6, which receives the serial signal 5. Since the detection unit of the error prevention encoder 4 and the transmitter 6 are stationary, that is, substantially fixed, they constitute a stationary device of the safety device 20 of the present invention.

  The data write barrier transmitter 6 transmits the serial signal 5 together with other data (not shown) by the frequency shift keying modulation method, and sends it to the data write barrier receiver 8 connected to the decoder 10. Since the receiver 8 and the decoder 10 are mounted on a device to be monitored, such as a storage rack collection vehicle, they constitute a portable device of the safety device 20 of the present invention.

  The receiver 8 of the data write barrier transmits the received serial signal 5 to the error prevention decoder 10. This error prevention decoder is connected to the operating part of the safety device 20, which in the illustrated embodiment comprises power relays 11, 12 that can restore or stop the device 13.

  In order to be able to more easily distinguish emergency switch data from other data being transmitted, it is appropriate to transmit emergency switch data in a light beam having a separate data channel. In the case of FSK modulation, such a data channel can be generated by selecting a second carrier frequency along with the carrier frequency of the main channel. Therefore, for example, the carrier frequency of the main channel can be set to 10 MHz, and the carrier frequency of the auxiliary channel can be set to 100 kHz.

The encoder 4 associates the following bit strings organized in byte units with the states of the detection units 1 and 2 of the safety device.
[Table 1]
Emergency switch 1 Startup / recovery key switch Bit string ON OFF 7Fh 1Ah 43h 2Ch
ON ON FFh AAh C3h BCh
OFF Random 00h, 00h, 00h, 00h

If the emergency switch 1 is not operated, the first byte FFh or 7Fh encodes the start of the sequence so that the decoder 10 can synchronize the decoder 10 itself with the encoder 4. In the example, a maximum error rate of 10% is set. That is, the three bits may be wrong. The response of decoder 10 to inaccurate sequences is shown in the table below.
[Table 2]
Receive sequence error rate Decoder response 7Eh 18h 43h 3Ch 2/32 = 6.2% None 7Eh 18h 40h 2Ch 4/32 = 125% Safe state

  In an operation that achieves a certain disturbance tolerance accuracy, the error rate evaluation within a limited range is tolerant of breakage, but the safety device is comprehensive for more significant breakage of the serial signal. It is something to protect.

  If the emergency switch 1 is operated, the decoder 10 receives only zero. Even if it is a single zero, it instructs the decoder 10 that the power relays 11, 12 are turned off and the device 13 needs to be stopped. In this embodiment, the decoder must receive bit strings periodically at 50 millisecond intervals. In order to find the lack of signal information, a maximum delay of 70 milliseconds is set in the decoder. When the beam of the data write barrier is interrupted, the decoder cannot receive the bit string, and after a maximum of 70 milliseconds, the decoder controls the operating part of the safety device to a safe state.

It is a mimetic diagram showing an embodiment of a safety device concerning the present invention.

Explanation of symbols

  1 emergency switch, 2 start-up recovery switch, 4 error prevention encoder, 5 serial signal, 6 transmitter, 8 receiver, 10 error prevention decoder, 11, 12 power relay, 13 device, 20 safety device.

Claims (11)

A device that sends data to a protected device,
  a) a stationary device (1, 2, 4, 6) having a transmitter (6) for wireless transmission of data as part of a data write barrier;
  b) A portable device (8, 10, 11, 12, 13) mounted on the device to be protected and having a receiver (8) that wirelessly receives the data as another part of the data write barrier. When,
  c) The stationary device (1, 2, 4, 6) includes a detection unit (1, 2) that receives security data,
  d) The portable device (8, 10, 11, 12, 13) has an operation unit (11, 12, 13) for controlling the device to be protected to a safe state, and the security data The operating parts (11, 12, 13) operating on the basis are operatively associated with the detecting parts (1, 2),
  e) the transmitter (6) and the receiver (8) are designed for wireless transmission and reception of the security data;
  f) An error prevention encoder (4) for encoding the security data to be transmitted is provided connected to the transmitter (6) and the detector (1, 2),
  g) an error prevention decoder (10) for decoding the received security data is provided connected to the receiver (8) and the operating unit;
  h) The transmitter (6) and the receiver (8) transmit the security data through another channel by distinguishing the security data from other data to be transmitted, and are configured to support multi-channel data transmission. A device characterized by that. The portable device (8,10,11,12,13), especially in an automatic storage rack system, a vehicle, a lifting mechanism, configured to be mounted on at least one of the other transport mechanism characterized Rukoto, equipment according to claim 1. The detection unit (1, 2) has at least one of an emergency switch, a light barrier, an optical key switch, a proximity switch, and other sensors. equipment of. The error prevention decoder equipment according to any one of claims 1 to 3, characterized in that a comparator and a data memory. Said decoder (10), have a time measurement device, if not received any data columns within the prescribed time interval, according to claim 1, wherein the controller controls the operation unit in a safe state equipment according to any one of. A data transmission method using the apparatus according to claim 1,
  a) Data is transmitted wirelessly using a transmitter (6) which is part of the stationary device (1, 2, 4, 6),
  b) The data is received wirelessly by a receiver (8) which is a part of a portable device (8, 10, 11, 12, 13) mounted on a device to be protected, and the transmitter ( 6) and the receiver (8) become part of the data write barrier;
  c) Security data is recorded by the detection unit (1, 2) of the stationary device (1, 2, 4, 6),
  d) The security data is transmitted to the operation unit (11, 12, 13) of the portable device (8, 10, 11, 12, 13), and the operation unit is driven based on the transmitted security data. And if it is specific security data, the device to be protected is controlled to a safe state,
  e) using the transmitter (6) and the receiver (8) of the data write barrier, the security data is transmitted in a wireless manner;
  f) Using the error prevention encoder (4) connected to the transmitter (6) and the detector (1, 2), the security data to be transmitted is encoded before transmission,
  g) using the error prevention decoder (10) connected to the receiver (8) and the operating unit, after transmission, the received security data is decoded;
  h) The data transmission method, wherein the security data is transmitted through a different channel so as to be distinguished from other transmission target data. The error prevention encoder (4) associates the serial data string (5) with the states of the detection units (1, 2),
The error prevention decoder (10) compares the received serial data string (5) with a preset data string stored in the decoder (10),
7. Method according to claim 6 , characterized in that the operating part (11, 12, 13) is activated based on the result of the comparison. 8. Method according to claim 7 , characterized in that the operating part (11, 12, 13) is controlled to a safe state when a signal error is detected. When comparing the received data sequence with the stored preset data sequence, the error prevention decoder sets an error rate,
The decoder (10) stores a limit value of an allowable error rate, and if the limit value is exceeded, the operating unit (11, 12, 13) is in a safe state, in particular a danger. 9. A method according to claim 7 or 8 , characterized in that the method is controlled to a safe state that includes a stoppage of active movement. The data string is organized in bytes,
10. Method according to any one of claims 6 to 9 , characterized in that the control of the operating part (11, 12, 13) to a safe state is performed by a specific byte, in particular a zero byte. . In order to clearly distinguish data relating to emergency switch-off from other data transmitted, the emergency switch-off data is transmitted on a separate data channel by frequency shift keying (FSK) modulation. The method according to any one of claims 6 to 10 .

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