lejos.robotics.LinearActuator Maven / Gradle / Ivy
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package lejos.robotics;
/**
* Interface that defines the minimal implementation for a Linear Actuator device. Linear Actuator classes should provide
* non-blocking extend/retract actions through the move() and moveTo() methods.
* Stall detection must be provided to avoid motor damage due to running against the end stops, etc.
*
* Motor regulation is not specified in this interface as it may be difficult to determine the accurate length per time
* (ie. mm/sec) rate due to encoder tick granularity of the linear actuator. It is up to the implementor to decide if the
* move() and moveTo() methods should produce regulated movement.
*
* @see lejos.hardware.device.LnrActrFirgelliNXT
* @author Kirk P. Thompson
*/
public interface LinearActuator extends Encoder {
/**
* Set the power level 0%-100% to be applied to the actuator motor where 0% is no movement and 100% is full speed.
* @param power new motor power 0-100%
*/
public void setPower(int power);
/**
* Returns the current actuator motor power setting.
* @return current power 0-100%
*/
public int getPower();
/** The actuator should retract (negative distance value) or extend (positive distance value)
* in encoder ticks distance. The distance is specified to be relative to the actuator shaft position
* at the time of calling this method. The absolute unit per encoder tick is device-dependent and should be specified in the
* implementation documentation.
*
* Stall detection needs to be implemented to stop the actuator in the event of an actuator motor stall condition.
*
* If immediateReturn is true, this method should not block and return immediately. The actuator stops when the
* stroke distance is met or a stall is detected.
* @param distance The distance to move the actuator shaft
* @param immediateReturn true returns immediately, false waits for the action to complete (or a stall)
*/
public void move(int distance, boolean immediateReturn);
/** The actuator should move to absolute position in encoder ticks. The position of the actuator
* shaft on startup should be zero. The position of the actuator shaft should be set to zero when
* resetTachoCount() is called.
* @param position The absolute shaft position in encoder ticks.
* @param immediateReturn true returns immediately, false waits for the action to complete (or a stall)
*/
public void moveTo(int position, boolean immediateReturn);
/**Return true if the actuator is in motion due to a move() or moveTo() order.
* @return true if the actuator is in motion. false otherwise.
*/
public boolean isMoving();
/**
* Returns true if a move() or moveTo() order ended due to a stalled motor. This should
* behave like a latch where the
* reset of the stall status is done on a new move() or moveTo() order.
* @return true if actuator motor stalled during an move() or moveTo() order.
* false otherwise.
*/
public boolean isStalled();
/**
* Cause the actuator to stop immediately and resist any further motion. Cancel any move() or
* moveTo()orders in progress.
*/
public void stop();
/**Returns the absolute tachometer (encoder) position of the actuator shaft. The zero position of the actuator shaft is where
* resetTachoCount() was last called or the position of the shaft when instantiated.
*
* @return tachometer count in encoder ticks.
*/
public int getTachoCount();
/**Reset the tachometer (encoder) count to zero at the current actuator position.
*/
public void resetTachoCount();
}