Detection of trailing cables for surface mining equipment
On industrial sites, especially sites which utilize remotely operated or autonomous mobile equipment, there is a significant risk that the mobile equipment may inadvertently contact trailing or buried cables. Traditional cable detection systems are unable to detect three-phase AC power trailing cables. Disclosed embodiments eliminate or reduce the risk of inadvertently contacting such cables. In particular, a signal may be injected into the pilot wire of each cable by a transmitter. A receiver on the mobile equipment may detect this signal on the pilot wire within a cable, and initiate an alert in response to detecting a signal.
1 . A cable detection system comprising:
one or more antennas, installed on a mobile equipment, wherein each of the one or more antennas is configured to detect a signal within a frequency range; and
a receiver configured to, under a condition where any of the one or more antennas detect the signal,
demodulate the detected signal into a data stream,
determine whether or not the data stream matches a reference, and
under a condition where the determining determines that the data stream matches the reference, initiate an alert,
wherein the determining whether or not the data stream matches the reference includes:
attempting to detect a preamble in the data stream,
under a condition where not detecting the preamble in the data stream, determining that the data stream does not match the reference, and
under a condition where detecting the preamble in the data stream, extracting a data frame from the data stream based on the preamble, and determining whether or not the data stream matches the reference by determining whether or not the data frame matches the reference.
2 . The cable detection system of claim 1 , wherein the determining whether or not the data frame matches the reference includes:
extracting an identifier from a payload of the data frame;
comparing the identifier to the reference;
under a condition where the identifier matches the reference, determining that the data frame matches the reference; and
under a condition where the identifier does not match the reference, determining that the data frame does not match the reference.
3 . The cable detection system of claim 1 , wherein the frequency range is between 90 and 110 kilohertz.
4 . The cable detection system of claim 1 , wherein the detected signal is demodulated based on on-off keying (OOK) modulation.
5 . The cable detection system of claim 1 , wherein each of the one or more antennas comprises at least one loop antenna.
6 . A system comprising:
one or more of a cable detection system of claim 1 ; and
one or more transmitters that are each configured to transmit the signal along a pilot wire of at least one cable.
7 . The system of claim 6 ,
wherein the one or more transmitters are a plurality of transmitters, and
wherein each of the plurality of transmitters is configured to transmit the signal at a timing that is synchronized with each of the other plurality of transmitters.
8 . The system of claim 7 , wherein each of the plurality of transmitters is configured to determine the timing according to a Global Positioning System (GPS)-disciplined clock.
9 . The system of claim 7 , wherein each of the plurality of transmitters is configured to modulate the signal using on-off keying (OOK) modulation.
10 . The system of claim 7 ,
wherein each of the plurality of transmitters is configured to inject a stream of data frames, including said data frame that is extracted, into the signal, and
wherein each of the data frames comprises an identifier.
11 . The system of claim 10 , wherein the identifier in the data frames in the streams injected by all of the plurality of transmitters is identical.
12 . A mobile equipment comprising a cable detection system of claim 1 .
13 . The mobile equipment of claim 12 , wherein the alert comprises interlocking a work implement, such that the work implement is unable to move.
14 . The mobile equipment of claim 12 , further comprising one or more ground-engaging members, wherein at least one of the one or more antennas is located in front of at least one of the one or more ground-engaging members.
15 . The mobile equipment of claim 12 , wherein the mobile equipment comprises a trailing cable that supplies electrical power to the mobile equipment.
16 . The mobile equipment of claim 15 , wherein the mobile equipment comprises a cable reel to hold the trailing cable, and wherein each of the one or more antennas is shielded from the cable reel.
17 . The mobile equipment of claim 15 , wherein the trailing cable comprises a pilot wire on which the signal is transmitted.
18 . A cable detection system comprising:
one or more antennas installed on a mobile equipment, wherein each of the one or more antennas is configured to detect a signal; and
a receiver including:
a demodulator configured to demodulate the detected signal into a data stream, and
a microprocessor configured to
attempt to detect a preamble in the data stream,
when not detecting the preamble in the data stream,
determine that the data stream does not match a reference,
when detecting the preamble in the data stream, extract a data frame from the data stream based on the preamble,
extract an identifier from the data frame,
compare the identifier to a reference identifier,
when the identifier matches the reference identifier,
determine that the data stream matches the reference, and
when the identifier does not match the reference identifier,
determine that the data stream does not match the reference, and
when determining that the data stream matches the reference, initiate an alert.
19 . A system comprising:
one or more cable detection systems; and
a plurality of transmitters each configured to transmit a signal along a pilot wire of at least one cable at a timing that is synchronized with each of the other transmitters of the plurality of transmitters,
wherein each of the one or more cable detection systems includes:
one or more antennas, installed on a mobile equipment, wherein each of the one or more antennas is configured to detect the signal within a frequency range; and
a receiver configured to, under a condition where any of the one or more antennas detect the signal,
demodulate the detected signal into a data stream,
determine whether or not the data stream matches a reference, and
under a condition where the determining determines that the data stream matches the reference, initiate an alert.
20 . The system of claim 19 ,
wherein the determining whether or not the data stream matches the reference includes:
extracting an identifier from a payload of a data frame of the data stream,
comparing the identifier to the reference,
under a condition where the identifier matches the reference, determining that the data stream matches the reference, and
under a condition where the identifier does not match the reference, determining that the data stream does not match the reference.