wpid::Mechanism Class Reference

A Mechanism class that uses PID to control a motor group. Contains functions for moving to a relative or absolute angle both synchronously and asynchronously. More...

#include <Mechanism.h>

Public Member Functions
	Mechanism (vex::motor_group motors, float gear_ratio, std::string mech_id)
	Construct a new Mechanism object.
	Mechanism (vex::motor_group motors, float gear_ratio)
void	spin (int velocity)
	Spins the motor group at the specified velocity. Negative values will spin the motors backwards.
void	stop ()
	stops the motors using the default brake mode.
void	waitUntilSettled ()
	Waits for the mechanism to finish motion.
void	moveRelative (float position, float max_speed)
	Move the mechanism to a relative angle.
void	moveRelativeAsync (float position, float max_speed)
	Move the mechanism to a relative angle asynchronously.
void	moveAbsolute (float position, float max_speed)
	Move the mechanism to an absolute angle.
void	moveAbsoluteAsync (float position, float max_speed)
	Move the mechanism to an absolute angle asynchronously.
float	getPosition (vex::rotationUnits units)
	Get the position of the first motor in the group with the specified units.
void	resetPosition ()
	Resets the encoders in the group to 0.
void	setBrakeType (vex::brakeType type)
	Sets the brake type of the chassis.
void	setPID (PID pid)
	Set a PID object to the mechanism.
void	setOffset (float offset)
	Set the offset of the mechanism to add or subtract a constant angle.
void	setMaxAcceleration (float max_accel)
	Set the max acceleration of the mechanism. Every time the PID loop executes, it increments the speed of the mechanism by this value until the mechanism reaches it's maximum speed. Increase the value if the robot is ramping too slow, or decrease if it causes too much jerk.
void	setBounds (float lower_bound, float upper_bound)
	Set the bounds of the mechanism, such that it is unable to spin past these points. This check is only done during driver control and does not affect PID motion.

Detailed Description

A Mechanism class that uses PID to control a motor group. Contains functions for moving to a relative or absolute angle both synchronously and asynchronously.

Constructor & Destructor Documentation

Mechanism()

wpid::Mechanism::Mechanism	(	vex::motor_group	motors,
		float	gear_ratio,
		std::string	mech_id
	)

Construct a new Mechanism object.

Parameters

motors	the motors used on the mechanism
gear_ratio	the external gear ratio
mech_id	a string identifier for the mechanism to use during logging

Member Function Documentation

getPosition()

float Mechanism::getPosition

(

vex::rotationUnits

units

)

Get the position of the first motor in the group with the specified units.

Parameters

units

the rotation units to return

Returns

float the position of the motor

moveAbsolute()

void Mechanism::moveAbsolute	(	float	position,
		float	max_speed
	)

Move the mechanism to an absolute angle.

Parameters

position	the absolute angle to move to in degrees
max_speed	the max speed of the motors in velocityUnits::pct

moveAbsoluteAsync()

void Mechanism::moveAbsoluteAsync	(	float	position,
		float	max_speed
	)

Move the mechanism to an absolute angle asynchronously.

Parameters

position	the absolute angle to move to in degrees
max_speed	the max speed of the motors in velocityUnits::pct

moveRelative()

void Mechanism::moveRelative	(	float	position,
		float	max_speed
	)

Move the mechanism to a relative angle.

Parameters

position	the relative angle to move to in degrees
max_speed	the max speed of the motors in velocityUnits::pct

moveRelativeAsync()

void Mechanism::moveRelativeAsync	(	float	position,
		float	max_speed
	)

Move the mechanism to a relative angle asynchronously.

Parameters

position	the relative angle to move to in degrees
max_speed	the max speed of the motors in velocityUnits::pct

setBounds()

void Mechanism::setBounds	(	float	lower_bound,
		float	upper_bound
	)

Set the bounds of the mechanism, such that it is unable to spin past these points. This check is only done during driver control and does not affect PID motion.

Parameters

lower_bound	the lowest encoder value the mechanism may move to in degrees
upper_bound	the highest encoder value the mechanism may move to in degrees

setBrakeType()

void Mechanism::setBrakeType

(

vex::brakeType

type

)

Sets the brake type of the chassis.

Parameters

type	The brake type can be set to coast, brake, or hold

setMaxAcceleration()

void Mechanism::setMaxAcceleration

(

float

max_accel

)

Set the max acceleration of the mechanism. Every time the PID loop executes, it increments the speed of the mechanism by this value until the mechanism reaches it's maximum speed. Increase the value if the robot is ramping too slow, or decrease if it causes too much jerk.

Parameters

max_accel

a value to increment to ramp the speed up in velocityUnits::pct

setOffset()

void Mechanism::setOffset

(

float

offset

)

Set the offset of the mechanism to add or subtract a constant angle.

Parameters

offset

the offset in degrees

setPID()

void Mechanism::setPID

(

PID

pid

)

Set a PID object to the mechanism.

Parameters

PID	a PID object

spin()

void Mechanism::spin

(

int

velocity

)

Spins the motor group at the specified velocity. Negative values will spin the motors backwards.

Parameters

velocity

the velocity of the mechanism in velocityUnits::pct

---

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

• include/WPID/Mechanism/Mechanism.h
• src/WPID/Mechanism/Mechanism.cpp