Slip/skid discrimination device, brake control system, and slip/skid discrimination method
A slip-and-skid determining device includes an axle speed decider, a reference axle speed decider, and a determiner. The axle speed decider decides, for each of a plurality of axles, an axle speed changeable based on a rotational speed of a wheel. The reference axle speed decider decides, based on the axle speed and a physical quantity changeable during travel of a railway vehicle, a reference axle speed in the vehicle. The determiner determines, based on comparison between the axle speed and the reference axle speed, whether any slip or skid of the wheel occurs.
1 . A slip-and-skid determining device provided for each of one or more vehicles included in a railway vehicle, comprising:
axle speed deciding circuitry configured to decide, for each of a plurality of axles in a vehicle of the one or more vehicles, an axle speed changeable in accordance with a rotational speed of a wheel attached to each of the plurality of axles in the vehicle;
reference axle speed deciding circuitry configured to decide, based on the axle speeds of the plurality of axles in the vehicle and a physical quantity changeable during travel of the railway vehicle, a reference axle speed in the vehicle; and
determining circuitry configured to determine, based on comparison between the axle speed of one of the plurality of axles and the reference axle speed, whether any slip or skid of the wheel of the one of the plurality of axles occurs.
2 . The slip-and-skid determining device according to claim 1 , wherein
the one or more vehicles is a plurality of the vehicles, and
the reference axle speed deciding circuitry decides the reference axle speed based on the axle speeds of the plurality of axles in the vehicle and axle speeds of a plurality of axles in another vehicle of the plurality of vehicles.
3 . The slip-and-skid determining device according to claim 2 , wherein
the reference axle speed deciding circuitry selects, as the reference axle speed, a maximum value of speeds that are the axle speeds of the plurality of axles in the vehicle and the axle speeds of the plurality of axles in the another vehicle, and
the determining circuitry determines, based on comparison between the axle speed of the one of the plurality of axles and the reference axle speed, whether any skid of the wheel of the one of the plurality of axles occurs.
4 . The slip-and-skid determining device according to claim 2 , wherein
the reference axle speed deciding circuitry selects, as the reference axle speed, a minimum value of the axle speeds of the plurality of axles in the vehicle and the axle speeds of the plurality of axles in the another vehicle, and
the determining circuitry determines, based on comparison between the axle speed of the one of the plurality of axles and the reference axle speed, whether any slip of the wheel of the one of the plurality of axles occurs.
5 . The slip-and-skid determining device according to claim 1 , wherein
the reference axle speed deciding circuitry decides the reference axle speed based on the axle speeds of the plurality of axles in the vehicle and a speed of the railway vehicle.
6 . The slip-and-skid determining device according to claim 5 , wherein
the reference axle speed deciding circuitry selects, as the reference axle speed, a maximum value of speeds that are the axle speeds of the plurality of axles in the vehicle and the speed of the railway vehicle, and
the determining circuitry determines, based on comparison between the axle speed of one of the plurality of axles and the reference axle speed, whether any skid of the wheel of the one of the plurality of axles occurs.
7 . The slip-and-skid determining device according to claim 5 , wherein
the reference axle speed deciding circuitry selects, as the reference axle speed, a minimum value of the axle speeds of the plurality of axles in the vehicle and the speed of the railway vehicle, and
the determining circuitry determines, based on comparison between the axle speed of one of the plurality of axles and the reference axle speed, whether any slip of the wheel of the one of the plurality of axles occurs.
8 . The slip-and-skid determining device according to claim 1 , wherein
the reference axle speed deciding circuitry decides the reference axle speed that maintains a rate of change in the reference axle speed within a target range.
9 . The slip-and-skid determining device according to claim 8 , wherein
the reference axle speed deciding circuitry decides the reference axle speed that maintains the rate of change in the reference axle speed within the target range defined based on an acceleration of the railway vehicle.
10 . The slip-and-skid determining device according to claim 1 , further comprising:
axle acceleration deciding circuitry configured to decide an axle acceleration based on the axle speeds,
wherein the determining circuitry determines, based on comparison between the axle speed speeds and the reference axle speed or comparison between the axle acceleration and an acceleration of the railway vehicle, whether any slip or skid of the vehicle occurs.
11 . The slip-and-skid determining device according to claim 1 , wherein
the axle speed deciding circuitry decides, based on the rotational speed of the wheel attached to each of the plurality of axles, the axle speeds each corresponding to a circumferential speed of the wheel.
12 . A brake control system, comprising:
a brake control device configured to control, in accordance with a braking command indicating a target deceleration being a target value for a deceleration of the railway vehicle, a mechanical brake device provided for each of a plurality of wheels in a vehicle of one or more vehicles included in a railway vehicle, the mechanical brake device being configured to decelerate braking command the vehicle by pressing a frictional member against a rotor rotating during travel of the railway vehicle based on pressure of a fluid supplied; and
the slip-and-skid determining device according to claim 1 , wherein the brake control device includes
target brake force deciding circuitry configured to acquire the braking command and decide a target brake force being a brake force to achieve the target deceleration,
target pressure deciding circuitry configured to decide, based on the target brake force, a target pressure being a target value for the pressure of the fluid to be supplied to the mechanical brake device,
an output valve configured to compress the fluid supplied from a fluid source in accordance with the target pressure and supply the compressed fluid to the mechanical brake device, and
re-adhesion controlling circuitry configured to reduce, when a determination result is received from the slip-and-skid determining device and the determining circuitry in the slip-and-skid determining device determines that a skid of at least one wheel of the plurality of wheels occurs, the brake force generated by the mechanical brake device corresponding to the at least one wheel for which the occurrence of skid is determined by the determining circuitry.
13 . A slip-and-skid determining method performed by a slip-and-skid determining device provided for each of one or more vehicles included in a railway vehicle, comprising:
deciding, for each of a plurality of axles in a vehicle of the one or more vehicles, an axle speed changeable in accordance with a rotational speed of a wheel attached to each of the plurality of axles in the vehicle;
deciding a reference axle speed in the vehicle based on the axle speeds of the plurality of axles in the vehicle and a physical quantity changeable during travel of the railway vehicle; and
determining, based on comparison between the axle speed of one of the plurality of axles and the reference axle speed, whether any slip or skid of the wheel of the one of the plurality of axles occurs.