ExponentialProfileMeterVolts

class wpimath.trajectory.ExponentialProfileMeterVolts(constraints: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.Constraints)

Bases: pybind11_object

A Exponential-shaped velocity profile.

While this class can be used for a profiled movement from start to finish, the intended usage is to filter a reference’s dynamics based on ExponentialProfile velocity constraints. To compute the reference obeying this constraint, do the following.

Initialization: @code{.cpp} ExponentialProfile::Constraints constraints{kMaxV, kV, kA}; State previousProfiledReference = {initialReference, 0_mps};

Run on update: @code{.cpp} previousProfiledReference = profile.Calculate(timeSincePreviousUpdate, previousProfiledReference, unprofiledReference);

where unprofiledReference is free to change between calls. Note that when the unprofiled reference is within the constraints, Calculate() returns the unprofiled reference unchanged.

Otherwise, a timer can be started to provide monotonic values for Calculate() and to determine when the profile has completed via IsFinished().

Constructs a ExponentialProfile.

Parameters:: constraints – The constraints on the profile, like maximum input.

class Constraints

Bases: pybind11_object

Profile constraints.

property A → wpimath.units.units_per_second: The State-Space 1x1 system matrix.

property B → wpimath.units.meters_per_second_squared_per_volt: The State-Space 1x1 input matrix.

static fromCharacteristics(maxInput: wpimath.units.volts, kV: wpimath.units.volt_seconds_per_meter, kA: wpimath.units.volt_seconds_squared_per_meter) → wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.Constraints

static fromStateSpace(maxInput: wpimath.units.volts, a: wpimath.units.units_per_second, b: wpimath.units.meters_per_second_squared_per_volt) → wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.Constraints

property maxInput → wpimath.units.volts: Maximum unsigned input voltage.

maxVelocity() → wpimath.units.meters_per_second

Computes the max achievable velocity for an Exponential Profile.

Returns:: The seady-state velocity achieved by this profile.

class ProfileTiming

Bases: pybind11_object

Profile timing.

property inflectionTime → wpimath.units.seconds: Profile inflection time.

isFinished(t: wpimath.units.seconds) → bool

Decides if the profile is finished by time t.

Parameters:: t – The time since the beginning of the profile.
Returns:: if the profile is finished at time t.

property totalTime → wpimath.units.seconds: Total profile time.

class State(arg0: wpimath.units.meters, arg1: wpimath.units.meters_per_second)

Bases: pybind11_object

Profile state.

property position → wpimath.units.meters: The position at this state.

property velocity → wpimath.units.meters_per_second: The velocity at this state.

calculate(t: wpimath.units.seconds, current: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State, goal: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State) → wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State

Calculates the position and velocity for the profile at a time t where the current state is at time t = 0.

Parameters:

t – How long to advance from the current state toward the desired state.
current – The current state.
goal – The desired state when the profile is complete.

Returns:

The position and velocity of the profile at time t.

calculateInflectionPoint(current: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State, goal: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State) → wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State

Calculates the point after which the fastest way to reach the goal state is to apply input in the opposite direction.

Parameters:

current – The current state.
goal – The desired state when the profile is complete.

Returns:

The position and velocity of the profile at the inflection point.

calculateProfileTiming(current: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State, goal: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State) → wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.ProfileTiming

Calculates the time it will take for this profile to reach the inflection point, and the time it will take for this profile to reach the goal state.

Parameters:

current – The current state.
goal – The desired state when the profile is complete.

Returns:

The timing information for this profile.

timeLeftUntil(current: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State, goal: wpimath._controls._controls.trajectory.ExponentialProfileMeterVolts.State) → wpimath.units.seconds

Calculates the time it will take for this profile to reach the goal state.

Parameters:

current – The current state.
goal – The desired state when the profile is complete.

Returns:

The total duration of this profile.