A Traditional Motion-Law. Its name is often reduced to Mod-Sine.

A motion with continuous Velocity and Acceleration, from start to end. The Jerk is finite at its start and end.

Start Position -

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

End Position

Start Velocity and End Velocity

Start Acceleration and End Acceleration

Start Jerk and End Jerk

None

Start-Range

End- Range

0 ≤ Start-Range < End-Range ≤ 1

Velocity Coefficient :

Acceleration Coefficient :

Jerk Coefficient :

Jerk at Crossover :

The Modified Sinusoid motion-law has finite jerk throughout the segment.

It has an relatively low peak velocity, but a relatively high value of the nominal acceleration.

Dynamic Performance

This Motion-Law is a good general purpose type particularly in applications where the period ratio is between 5 and 10, particularly if the input drive is flexible or it has backlash. It performs well with respect to residual vibration after the segment is complete.

Pressure Angle Considerations

This one of the Traditional Motion-Laws that produce a relatively small pressure angle, and so a small cam for a given lift and pre-prescribed maximum pressure angle.

Drive Torques

The nominal drive torque characteristics and the actual torque values are low even for low values of Period Ratio are good for this motion-law. The low peak values and the smooth variation of drive torque during the motion-law further emphasize the suitability of this motion-law where the input drive is flexible or has backlash.

The Acceleration function is a series of Sinusoid functions.

•a ¼ Sine wave function, starting from zero acceleration, for 12.5% of the Segment-Width.

•a ½ Cosine function, for 75% the Segment-Width

•a ¼ Sine wave function, returning to zero acceleration, for 12.5% of the Segment-Width.