Sensor systems and methods for monitoring environmental variables of a rail-bound vehicle
Sensor systems and methods for measuring environmental parameters associated with a rail-bound vehicle having a plurality of carriages are disclosed. In an embodiment, the sensor system includes a plurality of sensors arranged in a separate carriage of the rail-bound vehicle at a defined distance from a reference point within the rail-bound vehicle. The sensor system further includes a control unit configured to receive measurement signals and time-shift the received measurement signals based on the defined distance and a velocity of the rail-bound vehicle to determine whether an event measured by the plurality of sensors is present at the same point in time in two or more signals of a modified (time-shifted) set of signals.
1 . A sensor system comprising:
a rail-bound vehicle having a plurality of carriages;
a plurality of sensors comprising a plurality of accelerometers, each accelerometer being arranged in a separate carriage of said rail-bound vehicle at a defined distance from a reference point within said rail-bound vehicle, and each accelerometer being configured to generate a vibration measurement signal based on detection of a vibration of an associated carriage, the vibration measurement signal being related to accelerations along a substantially vertical axis;
a velocity measurement device configured to determine a velocity of said rail-bound vehicle;
a control unit configured to:
receive the vibration measurement signal from each of said plurality of accelerometers;
time-shifting the received vibration measurement signals based on said velocity of the rail-bound vehicle and said defined distance between the accelerometers and said reference point by obtaining a quotient of said defined distance over the velocity of the rail-bound vehicle in order to form a modified set of vibration signals, such that a vibration measurement made by each accelerometer at the same geographical location appears to have occurred simultaneously;
determine whether an event measured by said plurality of accelerometers is present at the same point in time in at least two signals of said modified set of vibration signals-; and
determine, based on the determination of such an event, the presence of a damaged section of the railway track.
2 . The sensor system according to claim 1 , wherein said plurality of sensors further comprises a plurality of acoustic sensors, each acoustic sensor being arranged separate carriage of said rail-bound vehicle at a defined distance from the reference point within said rail-bound vehicle, and each acoustic sensor being configured to generate a sound detection signal based on sound measurements in an associated carriage;
wherein said control unit is further configured to:
receive the sound detection signal from each of said plurality of acoustic sensors;
time-shifting the received sound detection signals based on said velocity of the rail-bound vehicle and said defined distance between the acoustic sensors and said reference point in order to form a modified set of sound detection signals, such that a measurement made by each acoustic sensor at the same geographical location appears to have occurred simultaneously; and
determine whether an event measured by said plurality of acoustic sensors is present at the same point in time in at least two signals of said modified set of sound detection signals.
3 . The sensor system according to claim 1 , wherein said plurality of sensors further comprises a plurality of light sensors, each light sensor being arranged separate carriage of said rail-bound vehicle at a defined distance from the reference point within said rail-bound vehicle, and each light sensor being configured to generate a light detection signal based on light measurements in an associated carriage;
wherein said control unit is further configured to:
receive the light detection signal from each of said plurality of light sensors;
time-shifting the received light detection signals based on said velocity of the rail-bound vehicle and said defined distance between the light sensors and said reference point in order to form a modified set of light detection signals, such that a measurement made by each light sensor at the same geographical location appears to have occurred simultaneously; and
determine whether an event measured by said plurality of light sensors is present at the same point in time in at least two signals of said modified set of light detection signals.
4 . The sensor system according to claim 3 , further comprising:
a geolocation system arranged in said rail-bound vehicle for determining a geographical position of said rail-bound vehicle; and
wherein said control unit is configured to receive said geographical position from said geolocation system and determine a geographical location of said determined event based on said received geographical position.
5 . The sensor system according to claim 4 , wherein said control unit is configured to correlate said modified set of light detection signals with said determined geographical position in order to add redundancy to measurements performed by said geolocation system.
6 . The sensor system according to claim 3 , further comprising:
a lighting device arranged in each carriage which comprises a light sensor, each lighting device being operatively connected to said control unit; and
wherein said control unit is further configured to:
control each lighting device based on said modified set of light detection signals.
7 . The sensor system according to claim 1 , wherein said plurality of sensors further comprises a plurality of air pressure sensors, each air pressure sensor being arranged separate carriage of said rail-bound vehicle at a defined distance from the reference point within said rail-bound vehicle, and each air pressure sensor being configured to generate an air pressure detection signal based on air pressure measurements in an associated carriage;
wherein said control unit is further configured to:
receive the air pressure detection signal from each of said plurality of air pressure sensors;
time-shifting the received air pressure detection signals based on said velocity of the rail-bound vehicle and said defined distance between the air pressure sensors and said reference point in order to form a modified set of air pressure detection signals, such that a measurement made by each air pressure sensor at the same geographical location appears to have occurred simultaneously; and
determine whether an event measured by said plurality of air pressure sensors is present at the same point in time in at least two signals of said modified set of air pressure detection signals.
8 . The sensor system according to claim 7 , further comprising:
a geolocation system arranged in said rail-bound vehicle for determining a geographical position of said rail-bound vehicle; and
wherein said control unit is configured to receive said geographical position from said geolocation system and determine a geographical location of said determined event based on said received geographical position.
9 . The sensor system according to claim 8 , wherein said control unit is further configured to correlate said modified set of air pressure detection signals with said determined geographical position in order to add redundancy to measurements performed by said geolocation system.
10 . The sensor system according to claim 7 , further comprising:
a lighting device arranged in each carriage which comprises a light sensor and/or an air pressure sensor, each lighting device being operatively connected to said control unit; and
wherein said control unit is further configured to:
control each lighting device based on said modified set of air pressure detection signals.
11 . The sensor system according to claim 3 , wherein said plurality of sensors further comprises a plurality of air pressure sensors, each air pressure sensor being arranged separate carriage of said rail-bound vehicle at a defined distance from the reference point within said rail-bound vehicle, and each air pressure sensor being configured to generate an air pressure detection signal based on air pressure measurements in an associated carriage;
wherein said control unit is further configured to:
receive the air pressure detection signal from each of said plurality of air pressure sensors;
time-shift the received air pressure detection signals based on said velocity of the rail-bound vehicle and said defined distance between the air pressure sensors and said reference point in order to form a modified set of air pressure detection signals, such that a measurement made by each air pressure sensor at the same geographical location appears to have occurred simultaneously; and
determine whether an event measured by said plurality of air pressure sensors is present at the same point in time in at least two signals of said modified set of air pressure detection signals.
12 . The sensor system according to claim 11 , further comprising:
a lighting device arranged in each carriage which comprises a light sensor, each lighting device being operatively connected to said control unit; and
wherein said control unit is further configured to:
control each lighting device based on said modified set of light detection signals and/or said modified set of air pressure detection signals.
13 . The sensor system according to claim 2 , wherein the control unit is further arranged to use the events determined from the modified set of sound detection signals to filter the events determined from the modified set of vibration signals.
14 . The sensor system according to claim 1 , wherein each accelerometer is arranged in the same or similar position in each carriage, thereby providing the same structural surroundings for the accelerometers.
15 . The sensor system according to claim 1 , wherein the control unit is further configured to compare the modified set of vibration signals to previously acquired modified sets of vibration signals, acquired at the same location, and to determine a trend for the newly modified sets of vibration signals in relation to the previously acquired modified set of vibration signals.
16 . A sensor system comprising:
a rail-bound vehicle having a plurality of carriages;
a plurality of sensors comprising a plurality of accelerometers and a plurality of acoustic sensors, all accelerometers and all acoustic sensors, respectively, being arranged in separate carriages of said rail-bound vehicle at defined distances from a reference point within said rail-bound vehicle, each accelerometer being configured to generate a vibration measurement signal based on detection of a vibration of an associated carriage and each acoustic sensor being configured to generate a sound detection signal based on sound measurements in an associated carriage;
a velocity measurement device configured to determine a velocity of said rail-bound vehicle;
a control unit configured to:
receive the vibration measurement signal from each of said plurality of accelerometers and the sound detection signal from each of said plurality of acoustic sensors;
time-shifting the received vibration measurement signals and the received sound detection signals based on said velocity of the rail-bound vehicle and said defined distance between the accelerometers an acoustic sensors and said reference point respectively by obtaining a quotient of said defined distances over the velocity of the rail-bound vehicle in order to form modified sets of vibration signals and sound detection signals, such that a vibration measurement made by each accelerometer and a sound measurement made by each acoustic sensors at the same geographical locations appears to have occurred simultaneously; and
determine whether an event measured by said plurality of accelerometers is present at the same point in time in at least two signals of said modified set of vibration signals and an event measured by said plurality of acoustic sensors is present at the same point in time in at least two signals of said modified set of sound detection signals-; and
determine, based on the determination of such an event, the presence of a damaged section of the railway track.
17 . The sensor system according to claim 16 , wherein the control unit is further arranged to use the events determined from the modified set of sound detection signals to filter the events determined from the modified set of vibration signals.