A hydraulic actuator has a lower cylinder comprising a lower cylinder extension area and a lower cylinder retraction area, an upper cylinder comprising an upper cylinder extension area and an upper cylinder retraction area, and an actuator shaft. The actuator shaft has a lower cylinder piston disposed in the lower cylinder, an upper cylinder piston disposed in the upper cylinder, a lower shaft connecting the lower cylinder piston to the upper cylinder piston, and an upper shaft extending from the upper cylinder piston and at least partially externally from the upper cylinder. At least one of fluid flow of the lower cylinder matches fluid flow of the upper cylinder and (1) an internal diameter of the lower cylinder is not equal to the an internal diameter of the upper cylinder and (2) a diameter of the lower shaft is not equal to a diameter of the upper shaft.

This disclosure includes manipulating apparatuses and related methods. Some manipulating apparatuses include an actuator having a semi-rigid first segment, a semi-rigid second segment, and one or more flexible cells disposed between the first segment and the second segment, where the actuator is configured to be coupled to a fluid source such that the fluid source can communicate fluid to vary internal pressures of the one or more cells, and where each cell is configured such that adjustments of an internal pressure of the cell causes angular displacement of the second segment relative to the first segment.

This disclosure includes manipulating apparatuses and related methods. Some manipulating apparatuses include an actuator having a semi-rigid first segment, a semi-rigid second segment, and one or more flexible cells disposed between the first segment and the second segment, where the actuator is configured to be coupled to a fluid source such that the fluid source can communicate fluid to vary internal pressures of the one or more cells, and where each cell is configured such that adjustments of an internal pressure of the cell causes angular displacement of the second segment relative to the first segment.

A multi-redundancy electromechanical servo system for regulating a liquid rocket engine, comprising a triple-redundancy servo controller (1), a double-redundancy servo driver (2), double-winding electromechanical actuators (4, 5), a triple-redundancy position sensor (6), a thrust regulator (8) and a mixed ratio regulator (9). Engine thrust, a mixed ratio regulation instruction and a feedback signal of the triple-redundancy position sensor are inputted to the triple-redundancy servo controller, and the triple-redundancy servo controller outputs thrust and mixed ratio regulation PWM wave control signals to the double-redundancy servo driver. The double-redundancy servo driver outputs a three-phase variable-frequency variable-amplitude sine wave current to drive the double-winding electromechanical actuators to drive the thrust regulator and the mixed ratio regulator to move, thus achieving engine thrust and mixed ratio regulation. The present servo system has a simple system and excellent control characteristics, has the ability to control a two-degree fault operation and drive a one-degree fault operation, and significantly improves the reliability and usage maintainability of the thrust and mixed ratio regulation of the liquid rocket engine. Also disclosed is a method for implementing the foregoing multi-redundancy electromechanical servo system.

A multi-redundancy electromechanical servo system for regulating a liquid rocket engine, comprising a triple-redundancy servo controller (1), a double-redundancy servo driver (2), double-winding electromechanical actuators (4, 5), a triple-redundancy position sensor (6), a thrust regulator (8) and a mixed ratio regulator (9). Engine thrust, a mixed ratio regulation instruction and a feedback signal of the triple-redundancy position sensor are inputted to the triple-redundancy servo controller, and the triple-redundancy servo controller outputs thrust and mixed ratio regulation PWM wave control signals to the double-redundancy servo driver. The double-redundancy servo driver outputs a three-phase variable-frequency variable-amplitude sine wave current to drive the double-winding electromechanical actuators to drive the thrust regulator and the mixed ratio regulator to move, thus achieving engine thrust and mixed ratio regulation. The present servo system has a simple system and excellent control characteristics, has the ability to control a two-degree fault operation and drive a one-degree fault operation, and significantly improves the reliability and usage maintainability of the thrust and mixed ratio regulation of the liquid rocket engine. Also disclosed is a method for implementing the foregoing multi-redundancy electromechanical servo system.

A stability and command augmentation system for controlling an aircraft, comprising: a first member moveable by a pilot input device to a first position defining a first input; a second member moveable to a second position associated with a second input; and an adder device configured to add the first and second inputs and supply an output signal defining a command for an element to be controlled of the aircraft; the stability and command augmentation system comprises: a casing, a first and a second piston integrally movable with one another inside the casing and operatively connected to the second member; and control means configured to exert a first force on the first piston and a second force on the second piston; the second force is independent of the first force.

A stability and command augmentation system for controlling an aircraft, comprising: a first member moveable by a pilot input device to a first position defining a first input; a second member moveable to a second position associated with a second input; and an adder device configured to add the first and second inputs and supply an output signal defining a command for an element to be controlled of the aircraft; the stability and command augmentation system comprises: a casing, a first and a second piston integrally movable with one another inside the casing and operatively connected to the second member; and control means configured to exert a first force on the first piston and a second force on the second piston; the second force is independent of the first force.

A hydraulic system for a working machine includes a feeding pump; and a plurality of variable displacement hydraulic machines being connected in parallel to the feeding pump; At least one of the variable displacement hydraulic machines being is adapted to drive a ground engagement element of the working machine, and at least one of the variable displacement hydraulic machines is adapted to drive a vibrator for vibrating a ground engagement element of the working machine.

A hydraulic system for a working machine includes a feeding pump; and a plurality of variable displacement hydraulic machines being connected in parallel to the feeding pump; At least one of the variable displacement hydraulic machines being is adapted to drive a ground engagement element of the working machine, and at least one of the variable displacement hydraulic machines is adapted to drive a vibrator for vibrating a ground engagement element of the working machine.

A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body.