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About Motor

The motor represents the external source of power to animate a mechanism in Sketcher.

Three types of profiles are available to specify a motor:

This page discusses:

Constant Speed
Distance
Oscillating

See Also

Experiencing Motion Study of Mechanisms

The motor is attached to a mechanism's command, and this one defines the motor type.

The motor can be either linear (for translation-based commands), or angular (for rotation-based commands).
The motor specifies either a relative displacement or a velocity.
The maximum force for linear-type motors, or the maximum torque for angular-type motors can be specified. This value is taken into account by the dynamic solver.

You can attach a motor to each command of the mechanism.

Constant Speed

The constant speed profile establishes a constant speed motion, linear or angular, starting from a null speed.

The following parameters and formulae are used:


Symbol	Description
$t$	Time
$\dot{q}$	Velocity
$q = \dot{q} t$	Position

Distance

The distance profile establishes a relative displacement, linear or angular, following a cubic profile during a specified time.

The following parameters and formulae are used:


Symbol	Description
$t_{0}$	Starting time
$t_{1}$	Displacement time
$t$	Time
$q_{0}$	Amplitude
$\dot{q} = \frac{{- 6 q}_{0} {(t - t_{0})}^{2}}{{(t_{1} - t_{0})}^{3}} + \frac{{6 q}_{0} (t - t_{0})}{{(t_{1} - t_{0})}^{2}}$	Velocity
$q = \frac{{- 2 q}_{0} {(t - t_{0})}^{3}}{{(t_{1} - t_{0})}^{3}} + \frac{{3 q}_{0} {(t - t_{0})}^{2}}{{(t_{1} - t_{0})}^{2}}$	Position

Oscillating

The oscillating profile establishes a repetitive variation, linear or angular, according to an amplitude and a frequency.

The following parameters and formulae are used:


Symbol	Description
$t$	Time
$f$	Frequency
$φ$	Phase shift
$A$	Amplitude
$\dot{q} = A π \sin (2 π f t - φ)$	Velocity
$q = \frac{A}{2} (\sin (2 π f t - \frac{π}{2} - φ) + 1)$	Position