Motion-Law: Constant-Velocity

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Motion-Law: Constant-Velocity

Constant-Velocity Cam-Law, Motion-Law

This is a Polynomial motion type

See also : Constant-Velocity: Two Positions.

Motion-Description

The Velocity is Constant for the period of the segment-width.  

Motion-Values

You CAN control the:

Start-Position

The Start-Position usually flows from the End-Position of the Previous-Segment.

Start-Velocity

The Start-Velocity usually flows from the End-Velocity of the Previous-Segment

You CANNOT control the:

End-Position

The End-Position is a calculated from the Start-Position, Start-Velocity, and Segment-Width

End-Velocity

The End-Velocity is equal to its Start-Velocity

End-Acceleration

End-Jerk

Example

Velocity Continuity

1.Use the Motion-Law Selector to change a motion-law of a segment to a Constant-Velocity.

2.Click above or below the segment in the motion-graphs.

The Constant-Velocity segment is now the Selected-Segment.

3.Open the Blend-Point Editor

MT-BPE-CB-DoFlow

1.Set the Match Control Button to Flow / Match - see image Red-14-3

The Velocity at the Start of the Selected-Segment is now forced to be equal to the Velocity at the End of the Previous-Segment.

The Start Velocity becomes read-only.

2.Edit the End VelocityRed-14-1b

See that the Start-VelocityRed-14-2 is always equal to the End-Velocity.
Blend-Point Editor: Velocity Equal at Blend-Point.

Blend-Point Editor: Velocity Equal at Blend-Point.
Smooth Flow of Velocity at Blend-Point Equal Gradients of Position Graph at Blend-Point

Smooth Flow of Velocity at Blend-Point
Equal Gradients of Position Graph at Blend-Point

Example continued...

VELOCITY DIS-CONTINUITY

Definition of dis-continuity: the motion-value of the motion-derivative changes instantly, with a step. A Dis-continuity is also called a Step-Change.

A discontinuity in Velocity is not recommended, of course.

A discontinuity in Velocity is also infinite acceleration - mechanically impossible.

A discontinuity puts a kink in the Position graph.

An example of a Velocity Dis-Continuity.

1.Use the Motion-Law Selector to change a motion-law of a segment to a Constant-Velocity.

2.Click above or below the segment in the motion-graphs.

The Constant-Velocity segment is now the Selected-Segment.

3.Open the Blend-Point Editor

MT-BPE-CB-DoNotFlow

4.Set the Match Control-Button to Do Not MatchRed-14-3

5.Enter a Start-VelocityRed-14-1b value that is not equal to the End-VelocityRed-14-2 value.
Blend-Point Editor: Velocities at Blend-Point are not Equal

Blend-Point Editor: Velocities at Blend-Point are not Equal
Step in Velocity Graph, & Kink(corner) in Position Graph. Step in gradient at Blend-Point in Position-Graph.

Step in Velocity Graph, & Kink(corner) in Position Graph.
Step in gradient at Blend-Point in Position-Graph.