Abstract: An industrial truck comprises a lift frame having a load part for carrying a load and a hydraulic system including at least one hydraulic cylinder having a piston rod disposed within a cylindrical housing, and a hydraulic power unit. At least one sensor is configured to determine at least one of: (i) an actual speed of the piston rod of the at least one hydraulic cylinder, and (ii) an actual acceleration of the piston rod of the at least one hydraulic cylinder. Furthermore, a control unit is configured to: (i) receive at least one of a target speed of the piston rod and a target acceleration of the piston rod, (ii) determine at least one of a speed control deviation value from the target speed, and an acceleration control deviation value from the target acceleration, and, (iii) regulate at least one of the actual speed of the piston rod based on the actual speed control deviation value and the actual acceleration of the piston rod based on the actual acceleration control deviation value.

Abstract: A fluid cylinder including a piston rod that is guided in a cylinder casing and on which a marking is provided with equidistantly arranged marks. An optical sensor unit is directed toward the marking. The optical sensor includes two or more equidistantly arranged optoelectronic sensor elements, which are configured to generate a binary output signal. The axial spacing between the optoelectronic sensor elements and the marks is such that each binary output signal includes a predetermined phase shift relative to the chronologically following output signal. The marking has at least one reference mark for which an output signal exists in all of the optoelectronic sensor elements. The optical sensor unit includes an error detection that converts the binary output signals from the optoelectronic sensor elements into a Gray code.