BRAKE ABNORMALITY DETERMINATION DEVICE, BRAKE STATE STORAGE DEVICE, ABNORMALITY DETERMINATION METHOD, ABNORMALITY DETERMINATION PROGRAM, AND BRAKE CONTROL DEVICE

A control device for an air brake device (50) includes an instruction value obtaining unit (86) that obtains an instruction value (A) of an air pressure supplied to an air brake device (50) when braking a railway vehicle (10). The control device further includes a cylinder pressure value obtaining unit (87) that obtains a brake cylinder pressure value (B) calculated from the instruction value (A) through a deceleration feedback control. The control device further includes a determination unit (83) that determines whether there is an abnormality of the air brake device (50) based on a brake efficiency (C) indicating a ration between the instruction value (A) and the brake cylinder pressure value (B).