pneumatic_tutorials

Introduction:

This video is a demonstration of the Pneumatic Sequencing Tutorials by Kevin Clague. The goal of these tutorials is to familiarize students with sequencing pneumatic switches using a constant airflow as an input. There are six circuits in total. Each circuit will be presented with a brief theory of operation, a picture of the provided design, the Boolean Algebra associated with the circuit, a graphical representation, and finally a visual demonstration of the circuit functioning.

Notation:

Unless otherwise noted, the cylinders will be labeled left to right alphabetically. The node at the base of the pneumatic cylinder will be notated with an “x” and the node at the top with a “c.” In the algebraic expressions, when a cylinder, such as cylinder A, is contracted, it will be labeled “~A” read as “not A.” When the cylinder is expanded it will not have the “~.”

Circuit 1:

Theory Of Operation: Circuit one uses two pistons and two switches to create a follower circuit. The output of piston B directly mimics the output of piston A. This creates a simple four step sequencer.

Boolean Algebra:

Ax = ~B

Ac = B

Bx = A

Bc = ~A

Video Demonstration

Circuit 2:

Theory Of Operation: Circuit two uses the same two pistons and switches from circuit one, and adds a third piston C to be synchronized with piston B. Piston C however, expands and contracts at a slightly faster rate than piston B, due to piston C not having the load of the switch.

Boolean Algebra: Ax = ~B

Ac = B

Bx = A

Bc = ~A

Cx = A

Cc = ~A

Video Demonstration

Circuit 3:

Theory Of Operation: Circuit three builds on the concept on synchronizing two pistons from circuit two. This time, two switches are attached to piston C. When these two switches are integrated into the design, piston C now waits until piston B begins is expansion or contraction to do the same. Now the two pistons are synchronized. Two ports on switches C1 and C2 are plugged to prevent air pressure from escaping.

Boolean Algebra:

Ax = ~B & ~C

Ac = B & C

Bx = A

Bc = ~A

Cx = A

Cc = ~A

Video Demonstration

Circuit 4:

Theory Of Operation: Circuit four uses the same pistons and switches as circuit three, only this time the hoses and therefore the algebra is switched. The hoses are rearranged to invert piston C and thus making it perform the opposite motions of piston B.

Boolean Algebra:

Ax = ~BC

Ac = B~C

Bx = A

Bc = ~A

Cx = ~A

Cc = A

Video Demonstration

Circuit 5:

Theory Of Operation: In circuit five instead of synchronizing piston C with piston B, piston C is used to expand upon the sequencing idea from circuit one. Now all three pistons are placed in series with each other, and only expand or contract after the piston before. This creates a six step sequencer.

Boolean Algebra: Ax = ~C

Ac = C

Bx = A

Bc = ~A

Cx = B

Cc = ~B

Video Demonstration

Circuit 6:

Theory Of Operation: By adding another switch to piston C we can create the same outputs from circuit five, however, each output now has a decreased period. Instead of a six step sequencer we have built a five step sequencer that still has the outputs of each piston following the piston before it.

Boolean Algebra: Ax = ~B~C

Ac = B

Bx = A

Bc = ~AC

Cx = B

Cc = ~B

Video Demonstration

Circuit 7:

Theory Of Operation: Circuit seven was created with the idea of building a four legged walker with two pairs of legs that make the same motions. The legs that are raised must come down before the other two move up in order to keep the walker from falling over.

Boolean Algebra: Ax = C

Ac = B~C

Bx = ~C

Bc = AC

Cx = ~A

Cc = ~B

Video Demonstration

Circuit 8:

Theory Of Operation: When circuit screen was initially implemented, the creator found that the walker would fall to the ground due to gravity when A was depressurized. To solve this problem, a pressurized copy of both pistons A and B were added to support the load.\\Note: In this circuit, the two pistons in the top row will be labeled as A’ and B’ in order to associate them with their non-pressurized counterparts

Boolean Algebra: A’x = C

A’c = B~C

Ax = A’

Ac = ~A’

B’x = ~C

B’c = AC

Bx = B’

Bc = ~B’

Cx = ~A

Cc = ~B

Video Demonstration