Method for retarder control and control apparatus for the same

A method for filling a hydrodynamic retarder having a rotor, a stator, and a working chamber disposed between the rotor and the stator, wherein the working chamber is filled from a reservoir that feeds to a valve into the retarder and the reservoir is pressurizable with an air pressure Pv for feeding operating fluid into the retarder at a control pressure Py, the method comprising:

• switching the retarder on;
• during passage of a first time period T1, delivering an overshoot control pressure Py(O) which is above a rated pressure PyRated established in the retarder for a rated braking torque which is to be set;
• during a second time period following the first time period, reducing the overshoot control pressure Py(O) to the rated pressure PyRated;
• setting the overshoot control pressure and the duration of the time periods T1 and T2 as a function of at least one of the following variables for insuring rapid switching on the retarder with reduced delay of the braking effect, the variables being at least one selected from the group consisting of:
• reservoir air pressure Py, retarder oil temperature, retarder rotational speed or vehicle velocity, vehicle lateral acceleration, ABS signal, axle load, brake-pause interval, operating fluid level, outside temperature, speed of the actuating element, acceleration of the set point value settings;
• wherein as the variable of the retarder oil temperature rises, the variables of the overshoot control pressure and the time periods are decreased.