The present disclosure relates to an apparatus for the position determination of a cylinder piston located in a cylinder liner, said apparatus comprising: a port for coupling an electrical signal into or out of the interior of the cylinder liner, wherein a signal coupled into the interior of the cylinder liner interacts with the cylinder piston. The present disclosure is characterized by a unit for determining the position of the cylinder piston which is connected to the port and which is configured to determine the position of the cylinder piston in the cylinder liner with the aid of a vectorial measurement of a signal decoupled from the cylinder liner.

The invention relates to a distance-measuring device for determining a distance between a reflection body in a conducting structure and a coupling region for electromagnetic waves, which region is provided on an end section of the conducting structure, said measuring device comprising a transmitting and receiving device, and a conduction junction (1) provided on the coupling region, for coupling the transmitting and receiving device to the conducting structure containing a medium, in order to couple an electromagnetic wave into the conducting structure, and to decouple the electromagnetic wave, reflected on the reflection body, from the conducting structure. Said measuring device also comprises an evaluation device for determining the distance between the coupling region and the reflection body from the complex reflection coefficient between the coupled electromagnetic wave and the decoupled electromagnetic wave. The invention also relates to the corresponding method.

The invention relates to a distance-measuring device for determining a distance between a reflection body in a conducting structure and a coupling region for electromagnetic waves, which region is provided on an end section of the conducting structure, said measuring device comprising a transmitting and receiving device, and a conduction junction (1) provided on the coupling region, for coupling the transmitting and receiving device to the conducting structure containing a medium, in order to couple an electromagnetic wave into the conducting structure, and to decouple the electromagnetic wave, reflected on the reflection body, from the conducting structure. Said measuring device also comprises an evaluation device for determining the distance between the coupling region and the reflection body from the complex reflection coefficient between the coupled electromagnetic wave and the decoupled electromagnetic wave. The invention also relates to the corresponding method.

A waveguide-coupling device (14) for a hydraulic cylinder (10) has an outer conductor element (22) to which a microwave signal can be supplied, an inner conductor element (24) for coupling a waveguide mode into a liquid-filled inner chamber (16) of the hydraulic cylinder (10) and a dielectric insulating element (22) arranged between the inner conductor element (24) and the outer conductor element (20), wherein the inner conductor element (24) and the dielectric insulating element (22) as well as the dielectric insulating element (22) and the outer conducting element (20) are each connected to each other in a liquid-tight manner.

A distance measuring apparatus and method for calculating a distance in a conducting structure are provided. One distance measuring apparatus provides for calculating a distance between a reflection body in a conducting structure and an injection point provided on an end section of the conducting structure for electromagnetic waves is provided. The distance measuring apparatus includes a transmitting and receiving device with a conduction cross-over provided at the injection point for the coaxially-inductive coupling of the transmitting and receiving device to the conducting structure in order to inject an electromagnetic wave into the conducting structure and to decouple the electromagnetic wave reflected on the reflection body from the conducting structure. The distance measuring apparatus also includes an analysis device for calculating a distance between the injection point and the reflection body from the phase difference between the injected electromagnetic wave and the decoupled electromagnetic wave.

The present disclosure relates to an apparatus for the position determination of a cylinder piston located in a cylinder liner, said apparatus comprising: a port for coupling an electrical signal into or out of the interior of the cylinder liner, wherein a signal coupled into the interior of the cylinder liner interacts with the cylinder piston. The present disclosure is characterized by a unit for determining the position of the cylinder piston which is connected to the port and which is configured to determine the position of the cylinder piston in the cylinder liner with the aid of a vectorial measurement of a signal decoupled from the cylinder liner.

The invention relates to a piston-cylinder unit. The piston-cylinder unit has a piston motion sensor which is arranged in a transverse hole of a cylinder head having a longitudinal axis. According to the invention, the piston motion sensor is detachably connected to a housing plug through a sensor cable. The housing plug is L-shaped. One leg of the housing plug extends in the transverse hole of the cylinder head, while another leg extends lying externally from the cylinder head. The invention enables the operation of the piston-cylinder unit with housing plugs of different types.

The piston-cylinder unit according to the invention finds, for example, use for a work machine, construction machine, agricultural machine, maritime machine, wheel loader, excavator, dumper, crane, forklift or lifting platform.

A hydraulic cylinder assembly includes a cylinder body, a piston configured to slide within an interior of the cylinder body, and a cylinder head coupled to the cylinder body. The cylinder head includes a cavity, and a bore that extends between the cavity and the interior of the cylinder body. The hydraulic cylinder assembly includes a radar sensing unit disposed within the cavity. The radar sensing unit includes a radar signal emitter and a radar signal detector oriented respectively to emit and detect radar signals through the bore into the interior of the cylinder body. The hydraulic cylinder assembly includes a dielectric lens between the radar sensing unit and the interior of the cylinder body, the dielectric lens having a convex side facing the radar sensing unit and a planar side opposite the convex side facing the interior of the cylinder body.

A method, system and non-transitory machine-readable storage devices for calibrating a radar sensor used in a hydraulic cylinder includes calculating a position-dependent noise estimate. The calibration also includes setting a position-dependent threshold amplitude for piston position detection based on the calculated position-dependent noise estimate. A piston is determined to be detected at a particular position if a reflected signal received at the radar sensor exceeds the position-dependent threshold amplitude at the particular position. The calibration further includes calibrating radar measurements acquired by the radar sensor to correct for a multi-path position error.