Method and device for measuring a parameter relevant to the journey of a rail vehicle

A measurement facility for a rail vehicle for measuring a parameter that is relevant to a journey of the rail vehicle by producing a parameter measurement value, the measurement facility comprising:

• a control facility configured to form the parameter measurement value that describes a frictional engagement between a rotational part and a rail traveled on by the rotational part, and to determine the parameter measurement value using a control loop, the control facility being configured to:
• ascertain a vehicle-side torque acting on the rotational part on a vehicle side, producing a vehicle-side torque value;
• calculate, by way of a calculation module and using the vehicle-side torque value and a frictional engagement torque value which describes a frictional engagement torque acting on the rotational part on the rail side, a rotational acceleration of the rotational part and thereby an expected rotational speed of the rotational part, producing a rotational estimated value;
• measure an actual rotational speed of the rotational part, producing a rotational measurement value;
• supply a difference between the rotational estimated value and the rotational measurement value to a control facility which outputs a controller output value at an output side, the controller output value being an initial estimated value that corresponds to a coefficient of adhesion between the rotational part and a rail or an initial estimated value that is at least proportional to the coefficient of adhesion between the rotational part and the rail;
• recalculate the frictional engagement torque value with the controller output value, the recalculated frictional engagement torque value being coupled back into the calculation module to close the control loop;
• consider the controller output value of the control facility and/or the recalculated frictional engagement torque value be the parameter measurement value to be measured;
• and
• provide the parameter measurement value to a vehicle control facility of the rail vehicle, the vehicle control facility configured to adjust at least one driving and/or braking parameter during the journey as a function of the provided parameter measurement value.