edu.nau.cs.scu
Class Servo

java.lang.Object
  edu.nau.cs.scu.Servo

public class Servo
extends java.lang.Object

This class represents a single axis of rotation for the gimbal. It contains all the position information and analysis necessary for the servo, along with information about soft and hard stops, the enabled/disabled status of the servo, and methods for inducing motion.

Author:

Bernard Jzexoia Avery

Constructor Summary

Servo()
This default constructor will load in default starting values for the servo.

Servo(double posHardStop, double negHardStop)
This constructor will initialize the servo with starting positions for positive and negative hard stops.

Method Summary

void	disable() Disable the servo.
void	enable() Enable the servo.
boolean	enabledStatus() This method will return the current enabled/disabled status of the servo.
double	getNegativeSoftStop() This method returns the negative soft stop of the servo.
double	getPosition() Return the current angle of the servo, based on a calculation based on the rate of motion, the position at the last move command, and the desired "goalAngle" if in position mode.
double	getPositiveSoftStop() This method returns the positive soft stop of the servo.
double	lowerBound() This method will return the limit of motion in the negative direction currently imposed on this servo.
void	setNegativeSoftStop(double s) Set the value of the negative soft stop, measured in radians.
void	setPosition(double a) This method will act as the "Position Mode" command would.
void	setPositiveSoftStop(double s) Set the value of the positive soft stop, measured in radians
void	setRate(double a) This command will simulate "Rate Mode" for one axis of rotation.
void	stop() This method will stop the servo in its tracks.
double	upperBound() This method will return the limit of motion in the positive direction currently imposed on this servo.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Servo

public Servo()

This default constructor will load in default starting values for the servo. It is not recommended to use this constructor, it is recommended to use Servo(double posSoftStop, double negSoftStop) instead.

Servo

public Servo(double posHardStop,
             double negHardStop)

This constructor will initialize the servo with starting positions for positive and negative hard stops. The positive and negative soft stops will be set equal to the hard stops when the servo is initialized.

Parameters:

posHardStop - The desired positive hard stop for this axis

negHardStop -

Method Detail

getPositiveSoftStop

public double getPositiveSoftStop()

This method returns the positive soft stop of the servo. this is distinct from getUpperBound in that getUpperBound will return either a hard stop OR a soft stop, depending on which one imposes the stricter limitation on movement.

Returns:

the positive soft stop for this axis of rotation.

getNegativeSoftStop

public double getNegativeSoftStop()

This method returns the negative soft stop of the servo. this is distinct from getLowerBound in that getLowerBound will return either a hard stop OR a soft stop, depending on which one imposes the stricter limitation on movement.

Returns:

the negative soft stop for this axis of rotation.

stop

public void stop()

This method will stop the servo in its tracks. This is called when the servo hits a stop or is disabled.

upperBound

public double upperBound()

This method will return the limit of motion in the positive direction currently imposed on this servo. This may be a hard or a soft stop depending on whether the positive soft stop has been set within the physical range of motion or outside of that range.

Returns:

The largest positive angle the servo can move to.

lowerBound

public double lowerBound()

This method will return the limit of motion in the negative direction currently imposed on this servo. This may be a hard or a soft stop depending on whether the positive soft stop has been set within the physical range of motion or outside of that range.

Returns:

The largest negative angle the servo can move to.

setPosition

public void setPosition(double a)

This method will act as the "Position Mode" command would. It will cause the servo to move at its default rate from its current angle to a desired new angle, then stop. If setPosition is issued with an angle greater than the current upperBound() or lower than the current lowerBound(), the servo will move to its closest bound instead.

Parameters:

a - The angle which the servo is being ordered to move to.

setRate

public void setRate(double a)

This command will simulate "Rate Mode" for one axis of rotation. When this method is called, the servo will begin moving at the specified rate.

Parameters:

a - The signed rate you wish the servo to move at.

getPosition

public double getPosition()

Return the current angle of the servo, based on a calculation based on the rate of motion, the position at the last move command, and the desired "goalAngle" if in position mode. This method will also account for hard and soft stops. This method will update the position before returning it, and so should be called by the program at least 50 times per second for accurate results. This method is called by getStatus() in PMCentralInterface so there is no need to individually call both methods.

Returns:

The current angle of the servo in radians.

setPositiveSoftStop

public void setPositiveSoftStop(double s)

Set the value of the positive soft stop, measured in radians

Parameters:

s - The new value for the positive soft stop, in radians.

setNegativeSoftStop

public void setNegativeSoftStop(double s)

Set the value of the negative soft stop, measured in radians.

Parameters:

s - The new value for the negative soft stop, in radians.

enable

public void enable()

Enable the servo. If the servo is disabled, no motion will be possible. Calling this method will allow future motion to take place as usual. Note that it will NOT restore any motion that was previously canceled by disable().

disable

public void disable()

Disable the servo. If the servo is disabled, no motion will be possible. Calling this method will stop the servo in its tracks at its current exact position. Once this method has been called, no further motion will be possible until enable() is called to cancel out this effect.

enabledStatus

public boolean enabledStatus()

This method will return the current enabled/disabled status of the servo.

Returns:

True if the servo is enabled, false if it is disabled.