In general, techniques are described regarding a rotary servo for actuators. A servo assembly includes a cylindrical outer sleeve including ports, a cylindrical outer spool annularly disposed within the cylindrical outer sleeve, a stepper motor mechanically coupled to the cylindrical outer spool, and an actuator mechanically coupled to compressor variable geometry that controls compression provided by a compressor. The cylindrical outer spool includes channels configured to provide fluidic interconnection between the ports and a cylindrical inner spool, where the cylindrical inner spool is annularly disposed within the cylindrical outer spool, and the cylindrical inner spool includes grooves configured to provide fluidic interconnection through the channels of the cylindrical outer sleeve. The stepper motor is configured to rotate the cylindrical outer spool within the cylindrical outer sleeve to deliver a fluid to and thereby actuate the actuator to control the compressor variable geometry.

The invention relates to a method for generating a control variable trajectory for an actuator so as to influence an input variable of a system, wherein a set point is supplied to the output variable of the system of a trajectory planning procedure, which from the set point generates a trajectory of constrained input values for a filter integrator chain and a trajectory of flat desired states, wherein the trajectory of constrained input values and the trajectory of flat desired states are supplied to a flatness-based feedforward control procedure that generates therefrom the control variable trajectory for the actuator, wherein in the trajectory planning procedure so as to generate the trajectory of constrained input values at least one constraint is applied in dependence upon the trajectory of flat desired states.

A hydraulic actuator includes a hydraulic cylinder; a piston within the hydraulic cylinder and movable in response to movement of hydraulic fluid in a hydraulic circuit coupled to the hydraulic cylinder; a synchronisation connection for receiving an input from a simultaneous transmission line; and a valve for controlling the flow of hydraulic fluid in the hydraulic circuit. The valve is a rotary valve comprising: a first valve section arranged to rotate in either a first rotational direction or a second rotational direction in response to input from the simultaneous transmission line in order to open a hydraulic flow path to the cylinder and urge the piston to move along the hydraulic cylinder in a corresponding first linear direction or second linear direction; and a second valve section arranged to rotate in either the first or second rotational direction.

A hydraulic actuator includes a hydraulic cylinder; a piston within the hydraulic cylinder and movable in response to movement of hydraulic fluid in a hydraulic circuit coupled to the hydraulic cylinder; a synchronisation connection for receiving an input from a simultaneous transmission line; and a valve for controlling the flow of hydraulic fluid in the hydraulic circuit. The valve is a rotary valve comprising: a first valve section arranged to rotate in either a first rotational direction or a second rotational direction in response to input from the simultaneous transmission line in order to open a hydraulic flow path to the cylinder and urge the piston to move along the hydraulic cylinder in a corresponding first linear direction or second linear direction; and a second valve section arranged to rotate in either the first or second rotational direction.

An actuator includes a housing and a piston including an axis. The piston and housing are configured to move relative to each other along the axis. The housing comprises at least one chamber for holding a fluid, the piston being positioned partially within the chamber. A seal configured to isolate the fluid in the chamber is positioned between the piston and the housing. The seal includes a seal body and an energiser. At least one pressure relief conduit is located between the energiser and the chamber. The pressure relief conduit configured to relieve fluid pressure built up in a region between the energiser and the chamber.

When a fluid is supplied to a first pressure-boosting chamber and/or a second pressure-boosting chamber of a pressure booster, either a first electromagnetic valve unit supplies a fluid discharged from a first pressurizing chamber to a second pressurizing chamber, or a second electromagnetic valve unit supplies a fluid discharged from a third pressurizing chamber to a fourth pressurizing chamber.

The invention relates to a method for generating a control variable trajectory for an actuator so as to influence an input variable of a system, wherein a set point is supplied to the output variable of the system of a trajectory planning procedure, which from the set point generates a trajectory of constrained input values for a filter integrator chain and a trajectory of flat desired states, wherein the trajectory of constrained input values and the trajectory of flat desired states are supplied to a flatness-based feedforward control procedure that generates therefrom the control variable trajectory for the actuator, wherein in the trajectory planning procedure so as to generate the trajectory of constrained input values at least one constraint is applied in dependence upon the trajectory of flat desired states.

An actuating system comprising a hydraulic actuator provided with a cylindrical cavity containing a piston configured to slide within the cylindrical cavity and a rod. The piston separates the cylindrical cavity into a first actuating chamber and a second actuating chamber. A first servo valve comprises a sheath including a first slider configured to slide within a cavity of the sheath on the basis of command signals from a command system. The cavity of the sheath comprises a first command chamber and a second command chamber on either side of the first slider. The first actuating chamber is fluidically connected to the first command chamber, and the second actuating chamber is fluidically connected to the second command chamber.

A rotary actuator includes a central housing; an output shaft that extends through the central housing; a vane that is mechanically coupled to the output shaft and divides the central housing into a first chamber and a second chamber; and a flow control mechanism that is moveable within the central housing and including a high pressure port and a low pressure port for communicating hydraulic fluid into and from the first and second chambers. The flow control mechanism is moveable to position the high pressure port and low pressure port relative to the first chamber and the second chamber for communication of the hydraulic fluid, thereby generating a pressure differential across the chambers. The vane rotates within the central housing in response to the pressure differential, and rotation of the vane drives the output shaft. A motor is configured to receive control signals to drive the movement of the flow control mechanism.

A rotary actuator includes a central housing; an output shaft that extends through the central housing; a vane that is mechanically coupled to the output shaft and divides the central housing into a first chamber and a second chamber; and a flow control mechanism that is moveable within the central housing and including a high pressure port and a low pressure port for communicating hydraulic fluid into and from the first and second chambers. The flow control mechanism is moveable to position the high pressure port and low pressure port relative to the first chamber and the second chamber for communication of the hydraulic fluid, thereby generating a pressure differential across the chambers. The vane rotates within the central housing in response to the pressure differential, and rotation of the vane drives the output shaft. A motor is configured to receive control signals to drive the movement of the flow control mechanism.