An example robot includes a hydraulic actuator cylinder controlling motion of a member of the robot. The hydraulic actuator cylinder comprises a piston, a first chamber, and a second chamber. A valve system controls hydraulic fluid flow between a hydraulic supply line of pressurized hydraulic fluid, the first and second chambers, and a return line. A controller may provide a first signal to the valve system so as to begin moving the piston based on a trajectory comprising moving in a forward direction, stopping, and moving in a reverse direction. The controller may provide a second signal to the valve system so as to cause the piston to override the trajectory as it moves in the forward direction and stop at a given position, and then provide a third signal to the valve system so as to resume moving the piston in the reverse direction based on the trajectory.

A fluidic actuator including an angled bottom plate having a cap and first and second plate arms on opposing sides of and extending from the cap. The fluidic actuator further includes a top plate coupled about the cap of the angled bottom plate and a rotatable coupling of the angled bottom plate and top plate.

A hydraulic system for controlling a hydraulic circuit of a working machine is disclosed. The hydraulic system can include a first hydraulic cylinder assembly, a second hydraulic cylinder assembly, a third hydraulic cylinder assembly and a valve. When coupled to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, the third hydraulic cylinder assembly can be configured to control a flow of a hydraulic fluid between the first hydraulic cylinder assembly and the second hydraulic cylinder assembly to limit an extent of travel of the first piston and an extent of travel of the second piston.

A milling machine may have a frame, a milling drum attached to the frame, and ground engaging tracks that support the frame and propel the milling machine in a forward or rearward direction. The milling machine may have height adjustable actuators connecting the frame to the tracks. Each actuator may have a cylinder attached to the frame, a piston slidably disposed within the cylinder, and a rod connected at a first end to the piston and connected to a track at a second end. The milling machine may have a tank storing hydraulic fluid and a fluid conduit connecting the tank to the cylinder. The milling machine may have a control valve selectively controlling a flow rate of the hydraulic fluid in the fluid conduit. The milling machine may also have a controller that determines a height of the frame relative to the ground surface based on the flow rate.

A solar tracker system having one or more solar trackers that each include one or more panels and one or more actuators coupled to the one or more panels, the one or more actuators having a first and second vessel; and an electronic control unit configured to inflate the first vessel with fluid from a fluid source and configured to separately inflate the second vessel with fluid from the fluid source. The electronic control unit is configured to determine that a stow event is present based on a first set of environmental data obtained from an environmental sensor that indicates environmental conditions pose a threat to the one or more solar trackers, and in response to determining that the stow event is present, actuate the one or more panels toward a stow configuration target angle by at least inflating the first or second vessels with fluid from the fluid source.

A fluidic actuation system for controlling rotation of one or more panels, having a first valve circuit configured to be fluidically coupled to a first vessel and a fluid source, having a first and second valve; and a second valve circuit configured to be fluidically coupled to a second vessel and the fluid source, having a third and fourth valve. The first valve is configured to control a supply of fluid from the fluid source to the first vessel; the second valve is configured to release fluid from the first vessel; the third valve is configured to control a supply of the fluid from the fluid source to the second vessel; and the fourth valve is configured to release the fluid from the second vessel. Introduction or release of fluid from one or both the first and second vessels is configured to cause rotation of the one or more panels.

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 servo valve unit capable of precisely controlling the position of a pneumatic cylinder that does not require a servo amplifier and a small sized and/or high durability servo valve unit are disclosed. The servo valve unit comprises a unit body having a first end portion and a second end portion, a first valve portion, a second valve portion, a first seal member that opens and closes the first valve portion, a second seal member that opens and closes the second valve portion, a first drive mechanism that drives the first seal member by a first electric pulse, a second seal member that drives the second seal member by a second electric pulse, a supply flow path that extends between the first end and the first valve, an exhaust flow path that extends between the second end and the second valve, a common flow path connected to the supply flow path and the exhaust flow path via the first valve portion and the second valve portion, and a drive flow path connected to the pneumatic actuator. The first drive mechanism and the second drive mechanism are arranged in a drive mechanism arrangement portion located between the first end portion and the second end portion. The drive air flow path can branch from a branch portion located between the drive mechanism arrangement portion and the first end portion and extends to the first end portion. Alternatively drive air flow path can branch from the common flow path from a branch portion located between the drive mechanism arrangement portion and the second end portion and extends to the second end portion.

A control loop for a double-acting pneumatic actuator is configured to generate two control signals, one for each of the two pneumatic chambers for the purpose of controlling the actuator position in view of operating constraints on the chamber pressures or the stiffness of the actuator. A numerical indicator of the stiffness may be computed in a variety of ways, for example, as the average of the two chamber pressures. In one embodiment a numerical indicator of stiffness is treated as an output of the system along with the position of the actuator. A multi-input multi-output control loop with position and pressure feedback may be used to simultaneously control the position and the stiffness of the actuator.

A operator supporting electrohydraulic drive and control system based on, position sensors (8) (9), a electronic control unite ECU (2), a recovery, storing and re-use system for energy, and with actuator (3) (4) and the drive control valve (6) (7) bolted together in one (3+6) (4+7) unite and with the valve (6) (7) independently of the ECU (2) is controlling effective use of pump capacity and recovery of energy and with control of speed for low speeds, or prevented speed by valves (6) (7) or pump (10) (10a) (11) (11a) displacement and for higher speed with control of deplacement of pumps and motors and with valves (6) (7) at the same time controlled to be fully open.