Motion and Mobility

In this section you can find all of Misty's API calls for motion and mobility.

MoveArm

Moves one or both of Misty's arms up and down.

Example Code

misty.move_arm("left", 50, 100)

When moving Misty's arms, it's helpful to understand their orientation.

• At 0 degrees, Misty's arms point straight forward along her X axis, parallel to the ground.

• At +90 degrees, Misty's arms point straight down towards the ground.

• At +/- 180 degrees, Misty's arms would face straight back, pointing toward her backpack; however, Misty's arms are not currently configured to move to this position.

• At -90/+270 degrees, Misty's arms would point straight up towards her head, perpendicular to the ground; however, the upward movement of Misty's arm movement is currently limited to -29 degrees.

Parameters

misty.move_arm(self, arm : str = None, position : float = None, velocity : float = None, duration : float = None, units : str = None)

• Arm (string) - The arm to move. You must use either left, right, or both.

• Position (double) - The new position to move the arm to. Use the Units parameter to determine whether to use position, degrees, or radians. Defaults to degrees.

• Velocity (double) - Optional. A value of 0 to 100, specifying the speed with which the arm should move. Defaults to null.

• Units (string) - Optional. A string value of degrees, radians, or position that determines which unit to use in moving Misty's arms.

MoveArms

Moves one or both of Misty's arms. You can control both arms simultaneously or one at a time.

Example Code

misty.move_arms(40, 40, 100, 100)

When moving Misty's arms, it's helpful to understand their orientation.

• At 0 degrees, Misty's arms point straight forward along her X axis, parallel to the ground.

• At +90 degrees, Misty's arms point straight down towards the ground.

• At +/- 180 degrees, Misty's arms would face straight back, pointing toward her backpack; however, Misty's arms are not currently configured to move to this position.

• At -90/+270 degrees, Misty's arms would point straight up towards her head, perpendicular to the ground; however, the upward movement of Misty's arm movement is currently limited to -29 degrees.

Parameters

misty.move_arms(self, leftArmPosition : float = None, rightArmPosition : float = None, leftArmVelocity : float = None, rightArmVelocity : float = None, duration : float = None, units : str = None)

• LeftArmPosition (double) - Optional. The new position of Misty's left arm. Use the Units parameter to determine whether to use position, degrees, or radians. Defaults to degrees.

• RightArmPosition (double) - Optional. The new position of Misty's right arm. Use the Units parameter to determine whether to use position, degrees, or radians. Defaults to degrees.

• LeftArmVelocity (double) - Optional. A value of 0 to 100 specifying the speed with which the left arm should move. Defaults to null.

• RightArmVelocity (double) - Optional. A value of 0 to 100, specifying the speed with which the right arm should move. Defaults to null.

• Units (string) - Optional. A string value of degrees, radians, or position that determines which unit to use in moving Misty's arms.

MoveHead

Moves Misty's head to a new position along its pitch, roll, and yaw axes.

Example Code

misty.move_head(-10, 30 ,0 ,100)

For the value ranges (by unit) for each direction of head movement, see the table below:

Dimension	Degrees	Position	Radians
pitch	-40 (up) to 26 (down)	-5 (up) to 5 (down)	-0.1662 (up) to 0.6094 (down)
roll	-40 (left) to 40 (right)	-5 (left) to 5 (right)	-0.75 (left) to 0.75 (right)
yaw	-81 (right) to 81 (left)	-5 (right) to 5 (left)	-1.57 (right) to 1.57 (left)

Parameters

misty.move_head(self, pitch : float = None, roll : float = None, yaw : float = None, velocity : float = None, duration : float = None, units : str = None)

• Pitch (double) - Value that determines the up or down position of Misty's head movement.

• Roll (double) - Value that determines the tilt ("ear" to "shoulder") of Misty's head.

• Yaw (double) - Number that determines the left to right turn position of Misty's head.

• Velocity (double) - Optional. The percentage of max velocity that indicates how quickly Misty should move her head. Value range: 0 to 100. Defaults to 10.

• Duration (double) - Optional. Time (in seconds) Misty takes to move her head from its current position to its new position.

• Units (string) - Optional. A string value of degrees, radians, or position that determines which unit to use in moving Misty's head. Defaults to degrees.

Drive

Drives Misty forward or backward at a specific speed until cancelled.

Example Code

misty.drive(60,60)

When using the Drive command, it helps to understand how linear velocity (speed in a straight line) and angular velocity (speed and direction of rotation) work together:

• Linear velocity (-100) and angular velocity (0) = driving straight backward at full speed.

• Linear velocity (100) and angular velocity (0) = driving straight forward at full speed.

• Linear velocity (0) and angular velocity (-100) = rotating clockwise at full speed.

• Linear velocity (0) and angular velocity (100) = rotating counter-clockwise at full speed.

• Linear velocity (non-zero) and angular velocity (non-zero) = Misty drives in a curve.

Parameters

misty.drive(self, linearVelocity : float = None, angularVelocity : float = None)

• LinearVelocity (double) - A percent value that sets the speed for Misty when she drives in a straight line. Default value range is from -100 (full speed backward) to 100 (full speed forward).

• AngularVelocity (double) - A percent value that sets the speed and direction of Misty's rotation. Default value range is from -100 (full speed rotation clockwise) to 100 (full speed rotation counter-clockwise). Note: For best results when using angular velocity, we encourage you to experiment with using small positive and negative values to observe the effect on Misty's movement.

DriveArc

Drives Misty in an arc. Misty continues driving until her current heading matches the desired absolute heading passed into this command.

Example Code

misty.drive_arc(0, 1, 4000, "false")

To get Misty's current heading, use the value for yaw from the IMU named object. To calculate Misty's velocity, use: ((desired_heading - current_heading) * (π/180) * radius) / (timeMs/1000).

Parameters

misty.drive_arc(self, heading : float = None, radius : float = None, timeMs : float = None, reverse : bool = None)

• Heading (double) - The absolute heading Misty should obtain when the arc is complete. To set the absolute heading, use either: 0 - 360, where 0 is straight ahead, 90 is directly to the left, 180 is straight behind, and 270 is directly to the right, or: -180 to 180, where 0 is straight ahead, 90 is directly to the left, 180 and -180 are straight behind, and -90 is directly to the right.

• Radius (double) - The radius (in meters) of the arc.

• TimeMs (double) - The duration (in milliseconds) that Misty drives.

• Reverse (boolean) - Optional. If true, Misty drives in reverse. Default is false.

DriveHeading

Drives Misty forward or backward in a straight line. While driving, Misty continuously adjusts her current heading to maintain the desired absolute heading.

Example Code

misty.drive_heading(0, 10, 4000, "false")

For a smooth driving experience, Misty's current heading should be within two degrees of the desired absolute heading before she executes the DriveHeading command. Variations of greater than two degrees result in large correction velocities. You can use the DriveArc command to face Misty in the direction of the heading you want her to maintain. Then, use the DriveHeading command to drive Misty forward or backward in a straight line. To calculate Misty's velocity, use distance / (timeMs/1000).

Parameters

misty.drive_heading(self, heading : float = None, distance : float = None, timeMs : float = None, reverse : bool = None)

• Heading (double) - The absolute heading Misty should maintain. To set the absolute heading, use either: 0 - 360, where 0 is straight ahead, 90 is directly to the left, 180 is straight behind, and 270 is directly to the right, or: -180 to 180, where 0 is straight ahead, 90 is directly to the left, 180 and -180 are straight behind, and -90 is directly to the right.

• Distance (double) - The distance (in meters) that Misty should drive.

• TimeMs (double) - The duration (in milliseconds) that Misty should drive.

• Reverse (boolean) - If true, Misty drives in reverse. Default is false.

DriveTime

Drives Misty forward or backward at a set speed, with a given rotation, for a specified amount of time.

Example code

misty.drive_time(40,40,1000,30)

When using the DriveTime command, it helps to understand how linear velocity (speed in a straight line) and angular velocity (speed and direction of rotation) work together:

• Linear velocity (-100) and angular velocity (0) = driving straight backward at full speed.

• Linear velocity (100) and angular velocity (0) = driving straight forward at full speed.

• Linear velocity (0) and angular velocity (-100) = rotating clockwise at full speed.

• Linear velocity (0) and angular velocity (100) = rotating counter-clockwise at full speed.

• Linear velocity (non-zero) and angular velocity (non-zero) = Misty drives in a curve.

Parameters

misty.drive_time(self, linearVelocity : float = None, angularVelocity : float = None, timeMs : int = None, degree : float = None)

• LinearVelocity (double) - A percent value that sets the speed for Misty when she drives in a straight line. Default value range is from -100 (full speed backward) to 100 (full speed forward).

• AngularVelocity (double) - A percent value that sets the speed and direction of Misty's rotation. Default value range is from -100 (full speed rotation clockwise) to 100 (full speed rotation counter-clockwise). Note: For best results when using angular velocity, we encourage you to experiment with using small positive and negative values to observe the effect on Misty's movement.

• TimeMs (integer) - A value in milliseconds that specifies the duration of movement. Misty will not drive if you pass in a value of less than 100 for this parameter.

• Degree (double) - (optional) The number of degrees to turn. Note: Supplying a Degree value recalculates linear velocity.

DriveTrack

Drives Misty left, right, forward, or backward, depending on the track speeds specified for the individual tracks.

Example Code

misty.drive_track(30,70)

Parameters

misty.drive_track(self, leftTrackSpeed : float = None, rightTrackSpeed : float = None)

• LeftTrackSpeed (double) - A value for the speed of the left track, range: -100 (full speed backward) to 100 (full speed forward).

• RightTrackSpeed (double) - A value for the speed of the right track, range: -100 (full speed backward) to 100 (full speed forward).

Halt

Stops all motor controllers, including drive motor, head/neck, and arm.

Example code

misty.halt()

Parameters

misty.halt(self, motorMask : int = None) 

motorMask (int): A bitmask representing the motors to be halted. Each bit in the mask corresponds to a specific motor or group of motors. The exact definition of each bit depends on Misty's hardware and firmware configuration.

Stop

Stops Misty's movement.

Example Code

misty.stop()

Important! Under most circumstances, it is best to avoid calling the Stop command with a Hold value of true. Holding Misty's position can strain Misty's drive motors. Stopping Misty's driving without holding her position should suffice under most circumstances and can prolong the life of your robot's drive motors.

Parameters

misty.stop(self, hold : bool = None)

• Hold (boolean) - Optional. Defaults to false. If true, Misty's drive motors remain engaged after Misty stops moving and attempt to hold the robot in its current position. This can be useful when Misty needs to stop moving while she's on an incline; sending a Stop command with a Hold value of true keeps the motors engaged, so that Misty does not roll down the slope. It is generally recommended to ignore the Hold parameter. Stopping Misty's driving without holding her position should suffice under most circumstances and can prolong the life of your robot's drive motors.

DriveToLocation (Misty II Pro)

Drives to a designated waypoint.

Important! Make sure to use StartTracking before using this command to have Misty start tracking her location, and use StopTracking to have her stop tracking her location after she arrives at the specified location.

Example Code

misty.drive_to_location("destination":"10:25")

Parameters

misty.drive_to_location(self, destination : GridCell = None)

• Destination (string) - A colon-separated integer pair that represents the X and Y coordinates of the destination. Note: GetMap obtains the occupancy grid for the most recent map Misty has generated. Use this grid to determine the X and Y coordinates of the destination. The X coordinate of a given cell is the index of the array for the cell. The Y coordinate of a cell is the index of that cell within its array

FollowPath (Misty II Pro)

Drives Misty on a path defined by coordinates you specify. Note that Misty must have a map and be actively tracking before starting to follow a path. Misty will not be able to successfully follow a path if unmapped obstacles are in her way.

Example Code

misty.follow_path(4:3,8:8,10:15)

Important! Make sure to use StartTracking before using this command to have Misty start tracking her location, and use StopTracking to have her stop tracking her location after she arrives at the specified location

Parameters

misty.follow_path(self, path : str = None, velocity : float = None, fullSpinDuration : float = None, waypointAccuracy : float = None, rotateThreshold : float = None)

• Path (string) - A string of comma-separated X:Y coordinates representing waypoints on a path for Misty to track through her currently active map. Each waypoint is a colon-separated integer pair representing the X and Y coordinates of a location on Misty's currently active map. Use GetMap to obtain the occupancy grid for Misty's current map, and use this grid to determine the X and Y coordinates of the destination.

• Velocity (double) - Optional. A fraction of Misty's max velocity. Determines how fast Misty moves when driving straight while following a path. Expects a decimal value greater than 0 and less than 1. Defaults to 0.5 (50% of max velocity) if not specified.

• FullSpinDuration (double) - Optional. Number of seconds it takes for Misty to complete a full spin (360 degrees) while following a path. Determines how fast Misty pivots or spins when changing direction. Defaults to 15 if not specified.

• WaypointAccuracy (double) - Optional. How close (in meters) the robot gets to a waypoint before considering itself to have reached that waypoint. Defaults to 0.1 if not specified.

• RotateThreshold (double) - Optional. The angle (in degrees) Misty's path following algorithm uses to determine when Misty should pivot toward a waypoint instead of continuing to drive straight. When following a path, Misty drives straight toward her next waypoint until the bearing between the waypoint and her current heading is greater than RotateThreshold degrees. When the bearing reaches this threshold, Misty pivots in the direction of the waypoint until the bearing is lower than RotateThreshold. When Misty reaches a waypoint, she spins to face the next waypoint and drives straight. As she approaches the waypoint, any error in the original spin causes the bearing angle to grow, causing Misty to stop and turn toward the waypoint; thus, Misty may stop and pivot multiple times between one waypoint and the next. Defaults to 10 if not specified.