Abstract: A method for checking the operability of a secondary-air system of an internal combustion engine includes measuring a first pressure between a first secondary-air pump and a first master secondary-air valve as well as a second master secondary-air valve, measuring a second pressure between a second secondary-air pump and a first slave secondary-air valve and a second slave secondary-air valve, controlling the first master secondary-air valve and the first slave secondary-air valve together, and controlling the second master secondary-air valve and the second slave secondary-air valve together. A secondary-air system includes a first control and a second control, wherein a first master secondary-air valve and a first slave secondary-air valve are controllable together by the first control and wherein a second master secondary-air valve and a second slave secondary-air valve are controllable together by the second control.

Abstract: A method for checking the operability of a secondary-air system of an internal combustion engine includes measuring a first pressure between a first secondary-air pump and a first master secondary-air valve as well as a second master secondary-air valve, measuring a second pressure between a second secondary-air pump and a first slave secondary-air valve and a second slave secondary-air valve, controlling the first master secondary-air valve and the first slave secondary-air valve together, and controlling the second master secondary-air valve and the second slave secondary-air valve together. A secondary-air system includes a first control and a second control, wherein a first master secondary-air valve and a first slave secondary-air valve are controllable together by the first control and wherein a second master secondary-air valve and a second slave secondary-air valve are controllable together by the second control.

Abstract: An engine apparatus is provided for a flying object, the engine apparatus including a combustion chamber having a throat region and a nozzle region, the nozzle region having a nozzle wall, wherein the nozzle region expands from the throat region towards an exit end relative to a combustion chamber axis, wherein the nozzle region has associated therewith a skirt having a skirt wall, the skirt being positioned downstream relative to the exit end and surrounding the exit end of the nozzle region, and wherein the skirt wall is at an acute angle away from the combustion chamber axis with respect to the nozzle wall, at least at the exit end of the nozzle region.

Abstract: A flying object is provided with an engine comprising a combustion chamber with a combustion space and a nozzle with a nozzle space following the combustion chamber, the transition between combustion chamber and nozzle lying in a plane in which a cross-section of the combustion space converges, in which thrust control in terms of magnitude and/or thrust vector can be carried out in a simple manner, it is provided that a centre body adapted to have combustion products flowing around it is at least partially arranged in the nozzle space, outside of the combustion space, and at least three jet vanes are arranged at the centre body.

Abstract: An engine apparatus is provided for a flying object, the engine apparatus including a combustion chamber having a throat region and a nozzle region, the nozzle region having a nozzle wall, wherein the nozzle region expands from the throat region towards an exit end relative to a combustion chamber axis, wherein the nozzle region has associated therewith a skirt having a skirt wall, the skirt being positioned downstream relative to the exit end and surrounding the exit end of the nozzle region, and wherein the skirt wall is at an acute angle away from the combustion chamber axis with respect to the nozzle wall, at least at the exit end of the nozzle region.

Abstract: In order to provide a flying object with an engine comprising a combustion chamber with a combustion space and a nozzle with a nozzle space following the combustion chamber, the transition between combustion chamber and nozzle lying in a plane in which a cross-section of the combustion space converges, in which thrust control in terms of magnitude and/or thrust vector can be carried out in a simple manner, it is provided that a centre body adapted to have combustion products flowing around it is at least partially arranged in the nozzle space, outside of the combustion space, and at least three jet vanes are arranged at the centre body.

Abstract: A method providing a rolling mill with compensation for changes occurring in rolling parameters that result from changes occurring in mill speed. The rolling parameters are under control of actuators that are connected to receive control reference voltages from electrical controllers. The method includes the step of generating a compensation function that describes the actuator movement required to maintain a rolling parameter at a desired level as a function of mill speed. This compensation function is used during mill speed changes to calculate a compensation value change for each actuator, a change that is required to maintain the parameter at the desired level. The compensation value change is added to a current level of the compensation value to provide a new, updated compensation value. The updated value is converted to a voltage for control of the actuator, and the voltage is added to the reference voltage of an associated electrical controller to provide a total voltage reference for the actuator.

Abstract: A method of rolling material in a rolling mill in which the material is directed from an unwind coil of the material to the mill and/or to a rewind coil of the material from the mill, the material being under tension as it is directed to and from the mill. The directing process has at least one cyclic disturbance which ordinarily causes cyclic changes in the tension of the material and in the thickness of the material exiting the mill. The method includes measuring changes in tension and/or thickness, and providing time domain samples of such changes during revolutions of the unwind or rewind coil. The samples are then processed by characterizing them as frequency, magnitude and phase-angle components of the changes using a function that transforms the time domain of the samples into the frequency domain. These components are then emloyed in an update algorithm to provide a current estimate of the cyclic disturbances.