Monitoring system for railway vehicle

A monitoring system for a railway vehicle, comprising:

• a detector that detects at least two of a pressure A1 of a first air spring, a pressure A2 of a second air spring, a pressure A3 of a third air spring, and a pressure A4 of a fourth air spring of the railway vehicle during running, the first air spring being disposed on a right front side in a running direction of the railway vehicle between a vehicle body and a railroad truck, the second air spring being disposed on a left front side in the running direction of the railway vehicle between the vehicle body and the railroad truck, the third air spring being disposed on a right rear side in the running direction of the railway vehicle between the vehicle body and the railroad truck, and the fourth air spring being disposed on a left rear side in the running direction of the railway vehicle between the vehicle body and the railroad truck;
• and
• a determiner that determines abnormality in a device that supports the vehicle body, based on the pressures detected by the detector,
• the determiner determining that abnormality has occurred when an integral value of a diagonal imbalance P obtained from an one of formulae (3) to (8) below at a certain mileage or elapsed time of the railway vehicle is equal to or greater than a certain value:
• P=A1−A2 (3)
• P=A3−A4 (4)
• P=A2+A3 (5)
• P=A1+A4 (6)
• P=A1−A3 (7)
• P=A2−A4 (8).

A monitoring system for a railway vehicle, comprising:

• a detector that detects at least one of a pressure A1 of a first air spring, a pressure A2 of a second air spring, a pressure A3 of a third air spring, and a pressure A4 of a fourth air spring of the railway vehicle during running, the first air spring being disposed on a right front side in a running direction of the railway vehicle between a vehicle body and a railroad truck, the second air spring being disposed on a left front side in the running direction of the railway vehicle between the vehicle body and the railroad truck, the third air spring being disposed on a right rear side in the running direction of the railway vehicle between the vehicle body and the railroad truck, and the fourth air spring being disposed on a left rear side in the running direction of the railway vehicle between the vehicle body and the railroad truck;
• and
• a determiner that determines abnormality in a device that supports the vehicle body, based on the pressure detected by the detector,
• the determiner determining that abnormality has occurred when an integral value of a diagonal imbalance P obtained from an one of formulae (9) to (12) below at a certain mileage or elapsed time of the railway vehicle is equal to or greater than a certain value:
• P=A1 (9)
• P=A2 (10)
• P=A3 (11)
• P=A4 (12).