Simulated Motor Path Generator¶
Contents
rcp.npath¶
Path generator objects for simulating low-level motion control.
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class
rcp.npath.
NPath
(N=4)[source]¶ Representation of a set of winch path generators. This keeps the physical calculations separate from the graphics. This reimplements the functionality of Path.h and Path.cpp in the StepperWinch Arduino sketch. The model is based on a second-order simple harmonic oscillator. The model is vectorized using numpy to calculate multiple models simultaneously. It uses single-precision floating point to better simulate the Arduino model.
The command API should be kept compatible with the winch interface class which transmits commands over a serial port to an Arduino-based winch.
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increment_reference
(axis, offset)[source]¶ Add a signed offset to one or more reference positions. This has the effect of applying a triangular impulse; the reference trajectory will make a step, then ramp back to the target vector.
The units are dimensionless ‘steps’. If using a microstepping driver, these may be less than a physical motor step.
- Parameters
axis – either a integer axis number or list of axis numbers
offset – either a integer step offset or list of step offsets
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increment_target
(axis, offset)[source]¶ Add a signed offset to one or more target positions. The units are dimensionless ‘steps’. If using a microstepping driver, these may be less than a physical motor step.
- Parameters
axis – either a integer axis number or list of axis numbers
offset – either a integer step offset or list of step offsets
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set_freq_damping
(axis, freq, damping)[source]¶ Set the second order model resonance parameters for one or more path generators. Note that the same parameters are applied to all specified axes, unlike the target setting functions.
- Parameters
axis – either a integer axis number or list of axis numbers
freq – scalar specifying the frequency in Hz
damping – scalar specifying the damping ratio, e.g. 1.0 at critical damping.
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set_speed
(axis, speed)[source]¶ Set the ramp speed of one or more targets in units/sec. If a speed value is less than or equal to zero, it is treated as unlimited, and the reference position will move in steps instead of ramps.
- Parameters
axis – either a integer axis number or list of axis numbers
speed – either a ramp speed or list of ramp speeds
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