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Adds PIDSubsystem and TrapezoidProfileSubsystem to Commands2. robotpy#28
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NewtonCrosby committed Dec 6, 2023
1 parent 9854bb2 commit b645b6b
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4 changes: 4 additions & 0 deletions commands2/__init__.py
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from .parallelracegroup import ParallelRaceGroup
from .perpetualcommand import PerpetualCommand
from .pidcommand import PIDCommand
from .pidsubsystem import PIDSubsystem
from .printcommand import PrintCommand
from .proxycommand import ProxyCommand
from .proxyschedulecommand import ProxyScheduleCommand
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from .startendcommand import StartEndCommand
from .subsystem import Subsystem
from .timedcommandrobot import TimedCommandRobot
from .trapezoidprofilesubsystem import TrapezoidProfileSubsystem
from .waitcommand import WaitCommand
from .waituntilcommand import WaitUntilCommand
from .wrappercommand import WrapperCommand
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"ParallelRaceGroup",
"PerpetualCommand",
"PIDCommand",
"PIDSubsystem",
"PrintCommand",
"ProxyCommand",
"ProxyScheduleCommand",
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"StartEndCommand",
"Subsystem",
"TimedCommandRobot",
"TrapezoidProfileSubsystem",
"WaitCommand",
"WaitUntilCommand",
"WrapperCommand",
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91 changes: 91 additions & 0 deletions commands2/pidsubsystem.py
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# Copyright (c) FIRST and other WPILib contributors.
# Open Source Software; you can modify and/or share it under the terms of
# the WPILib BSD license file in the root directory of this project.
from __future__ import annotations

from wpimath.controller import PIDController
from .subsystem import Subsystem


class PIDSubsystem(Subsystem):
def __init__(self, controller: PIDController, initial_position: float = 0.0):
"""
Creates a new PIDSubsystem.
:param controller: The PIDController to use.
:param initial_position: The initial setpoint of the subsystem.
"""
self.m_controller: PIDController = controller
self.setSetpoint(initial_position)
self.addChild("PID Controller", self.m_controller)
self.m_enabled = False

def periodic(self):
"""
Executes the PID control logic during each periodic update.
This method is called synchronously from the subsystem's periodic() method.
"""
if self.m_enabled:
self.useOutput(
self.m_controller.calculate(self.getMeasurement()), self.getSetpoint()
)

def getController(self) -> PIDController:
"""
Returns the PIDController used by the subsystem.
:return: The PIDController.
"""
return self.m_controller

def setSetpoint(self, setpoint: float):
"""
Sets the setpoint for the subsystem.
:param setpoint: The setpoint for the subsystem.
"""
self.m_controller.setSetpoint(setpoint)

def getSetpoint(self) -> float:
"""
Returns the current setpoint of the subsystem.
:return: The current setpoint.
"""
return self.m_controller.getSetpoint()

def useOutput(self, output: float, setpoint: float):
"""
Uses the output from the PIDController.
:param output: The output of the PIDController.
:param setpoint: The setpoint of the PIDController (for feedforward).
"""
raise NotImplementedError("Subclasses must implement this method")

def getMeasurement(self) -> float:
"""
Returns the measurement of the process variable used by the PIDController.
:return: The measurement of the process variable.
"""
raise NotImplementedError("Subclasses must implement this method")

def enable(self):
"""Enables the PID control. Resets the controller."""
self.m_enabled = True
self.m_controller.reset()

def disable(self):
"""Disables the PID control. Sets output to zero."""
self.m_enabled = False
self.useOutput(0, 0)

def isEnabled(self) -> bool:
"""
Returns whether the controller is enabled.
:return: Whether the controller is enabled.
"""
return self.m_enabled
73 changes: 73 additions & 0 deletions commands2/trapezoidprofilesubsystem.py
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# Copyright (c) FIRST and other WPILib contributors.
# Open Source Software; you can modify and/or share it under the terms of
# the WPILib BSD license file in the root directory of this project.
from __future__ import annotations

from .subsystem import Subsystem
from wpimath.trajectory import TrapezoidProfile

class TrapezoidProfileSubsystem(Subsystem):
"""A subsystem that generates and runs trapezoidal motion profiles automatically. The user specifies
how to use the current state of the motion profile by overriding the `useState` method.
This class is provided by the NewCommands VendorDep
"""
def __init__(
self, constraints: TrapezoidProfile.Constraints,
initial_position: float,
period: float = 0.02
):
"""
Creates a new TrapezoidProfileSubsystem.
:param constraints: The constraints (maximum velocity and acceleration) for the profiles.
:param initial_position: The initial position of the controlled mechanism when the subsystem is constructed.
:param period: The period of the main robot loop, in seconds.
"""
self.profile = TrapezoidProfile(constraints)
self.state = TrapezoidProfile.State(initial_position, 0)
self.setGoal(initial_position)
self.period = period
self.enabled = True

def periodic(self):
"""
Executes the TrapezoidProfileSubsystem logic during each periodic update.
This method is called synchronously from the subsystem's periodic() method.
"""
self.state = self.profile.calculate(self.period, self.goal, self.state)
if self.enabled:
self.useState(self.state)

def setGoal(self, goal: TrapezoidProfile.State):
"""
Sets the goal state for the subsystem.
:param goal: The goal state for the subsystem's motion profile.
"""
self.goal = goal

def setGoal(self, goal: float):
"""
Sets the goal state for the subsystem. Goal velocity assumed to be zero.
:param goal: The goal position for the subsystem's motion profile.
"""
self.setGoal(TrapezoidProfile.State(goal, 0))

def enable(self):
"""Enable the TrapezoidProfileSubsystem's output."""
self.enabled = True

def disable(self):
"""Disable the TrapezoidProfileSubsystem's output."""
self.enabled = False

def useState(self, state: TrapezoidProfile.State):
"""
Users should override this to consume the current state of the motion profile.
:param state: The current state of the motion profile.
"""
raise NotImplementedError("Subclasses must implement this method")

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