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 a motor.

• Control of flow gives control of speed, linear speed with a cylinder or RPM with a motor.

• Control 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 loop.

• 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.

• Partial 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.

• Full 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.

As can 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