Photo Gallery: Proportional Control
The pictures are of various projects
on which hydraulic proportional control were used to control
either pressure, flow or position.
In a hydraulic
system various outputs can be controlled using proportional valves, these valves
control either pressure, flow or direction.
- Control of pressure gives control of force, thrust with a cylinder or torque with
- Control of flow gives control
of speed, linear speed with a cylinder or RPM with a motor.
of direction gives control of position, linear position of a cylinder or rotational
position of a motor.
Hydraulic control can be
performed in one of three ways, open loop, partial closed loop and full closed
- Open loop, the electronic command signal
cannot be affected by the resultant movement of the actuator. This is usually
used for pressure or flow control when inaccuracies are acceptable.
Closed Loop, the electronic command signal can be affected by the resultant movement
of the actuator but only by the intervention of the machine operator (Man in the
Loop). This is often used to provide smoothness of operation and position control
in material handling machinery using joysticks.
Closed Loop, the electronic command signal is affected by feedback devices attached
to the actuator. This is used to give accurate control of pressure or flow and
is used for accurate position control.
be seen in the pictures we can provide systems that use all of these types of
control and can design systems using unusual types of control, radio, ultrasonic
and even laser.
Click image for close-up