onepi.utils.drive_pid.DrivePid Class Reference

Public Member Functions
	__init__ (self, pid_params=PidParams(), robot_params=RobotParams(), update_period_ms=100)
	move (self, left_speed_mmps, right_speed_mmps)
	stop (self)

Protected Member Functions
	_initialise (self)
	_compute_left_speed (self)
	_compute_right_speed (self)
	_update_speeds (self)

Protected Attributes
	_cut = ControlUtils(robot_params)
	_left_pid
	_right_pid
	_update_period_ms = update_period_ms
	_pid_timer

Static Protected Attributes
int	_left_speed = 0
int	_right_speed = 0
int	_previous_left_speed = 0
int	_previous_right_speed = 0
int	_counter = 0
int	_left_encoder = 0
int	_right_encoder = 0
	_one = BnrOneAPlus(0, 0)
bool	_initialised = False

Detailed Description

This class provides PID control for a differential drive robot.

Constructor & Destructor Documentation

__init__()

onepi.utils.drive_pid.DrivePid.__init__	(		self,
			pid_params = PidParams(),
			robot_params = RobotParams(),
			update_period_ms = 100 )

initialises the class with kp, ki, kd,
max speed (mm/s) and update period (ms)

Member Function Documentation

_compute_left_speed()

onepi.utils.drive_pid.DrivePid._compute_left_speed ( self )

protected

computes left speed

_compute_right_speed()

onepi.utils.drive_pid.DrivePid._compute_right_speed ( self )

protected

computes right speed

_initialise()

onepi.utils.drive_pid.DrivePid._initialise ( self )

protected

resets the system to be ready to start (again)

_update_speeds()

onepi.utils.drive_pid.DrivePid._update_speeds ( self )

protected

update wheel speeds by running the pid controller and sets the wheel
speeds of the robot

move()

onepi.utils.drive_pid.DrivePid.move	(		self,
			left_speed_mmps,
			right_speed_mmps )

Makes the robot move at the desired wheel speeds in mm/s

stop()

onepi.utils.drive_pid.DrivePid.stop

(

self

)

Stops the robot and stops the corresponding timer
used by the controller

Member Data Documentation

_left_pid

onepi.utils.drive_pid.DrivePid._left_pid

protected

Initial value:

=  PidController(
            pid_params, -robot_params.max_speed_mmps, robot_params.max_speed_mmps
        )

_pid_timer

onepi.utils.drive_pid.DrivePid._pid_timer

protected

Initial value:

=  SimpleTimer(
            increment=self._update_period_ms / 1000.0, function=self._update_speeds
        )

_right_pid

onepi.utils.drive_pid.DrivePid._right_pid

protected

Initial value:

=  PidController(
            pid_params, -robot_params.max_speed_mmps, robot_params.max_speed_mmps
        )

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The documentation for this class was generated from the following file:

• onepi/utils/drive_pid.py