Abstract: A parking brake system for a rail vehicle (100) contains a brake actuator (120) for receiving a parking-brake command (cmdP) and producing an electric brake-force signal (BF). A brake unit (200) contains first and second pressing members (211, 212) and a rotatable member (110) being mechanically linked to a wheel (105) of the rail vehicle (100). When receiving the electric brake-force signal (BF), the brake unit (200) causes the first and second pressing members (211, 212) to apply a braking force to the rotatable member (110) to keep the wheel (105) immobile. A gear assembly (220) in the brake unit (200) operates mechanically on the first and second pressing members (211; 212). In response to the electric brake-force signal (BF), an electric motor (230) acts on the gear assembly (220) to cause the first and second pressing members (211; 212) to attain a specified position interrelationship. An acceleration sensor (125) registers movements of the rail vehicle (100).

Abstract: A rail vehicle (100) obtains a basic parameter (?) reflecting an initial value of a friction coefficient (?e) relating to a rail segment (310) in a railway network (300) and validates the basic parameter (?) through a procedure involving: measuring individual rotational speeds (?1, ?2, ?3, ?4) of the axels to which the wheels (151, 152, 153, 154) of the rail vehicle (100) are connected while applying a gradually increasing brake force (BF) to a specific one of said axles; determining, while applying the gradually increasing brake force (BF), an absolute difference between the rotational speed (?2) of the specific one of said axles and an average rotational speed of said axles except the specific one of said axles; and in response to the absolute difference exceeding a threshold value deriving a parameter (?m) reflecting a measured value of the friction coefficient (?e); checking whether the measured value of the friction coefficient (?e) lies within an acceptance interval from the basic parameter (?); and if

Abstract: In a rail vehicle (100) a control unit (140) controls a set of brake/traction units (101, 161; 102, 162; 103, 163; 104, 164) by control signals (B1, A1; B2, A2; B3, A3; B4, A4) to apply a respective brake/traction force to a respective wheel axle (131, 132, 133, 134 to cause retardation/acceleration of the rail vehicle (100). The control unit (140) obtains a first wheel speed signal (?1) indicating a rotational speed of at least one first wheel (121), and obtains a second wheel speed signal (?a) indicating an average rotational speed of at least one second wheel (122, 123, 124). The control unit (140) produces a first control signal (BF; A1) to the first brake/traction unit (101, 161) such that this unit applies a gradually increasing brake/traction force to the first wheel axle (131) until an absolute difference (|?1??a|) between the first and second wheel speed signals (?1; ?a) exceeds a threshold value.

Abstract: A braking system for a rail vehicle (100) has a brake actuator (120) that receives a brake command (cmdB) and produces an electric brake-force signal (BF) commanding a brake action. A brake unit (200) receives the electric brake-force signal (BF) and causes an electric motor (230) to act on a gear assembly causing first and second pressing members (211) to move towards or away from a rotatable member (110) mechanically linked to at least one wheel (105) of the rail vehicle (100) to execute the brake action with respect to the rotatable member (110). If a deicing criterion (DI) is fulfilled, the brake actuator (120) is configured to produce the electric brake-force signal (BF) in such a way that the brake action involves moving the first and second pressing members (211; 212) away from the rotatable member (110) so as to remove any ice and/or snow on the brake unit (200).