Rethink Robotics Sawyer, Оригинальное руководство пользователя, Страница: 115 / 220

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Intera 5.3
Force Sensing and Selective Arm Stiffness
When it rotates the wheel, Sawyer will absorb some of the impact in the environment and perform
the task.
How to Access and Modify Force Data in Intera Studio
To display current force information, select the Shared Data button from the Task Bar. The live force
data is located under Robot Data.
Current forces on the arm are displayed in translation (force.x, y, and z) and rotation (torque. x, y,
and z). The user may select the desired units of measure in Settings. In this example, the units are
Newtons (N).
Compliance, Impedance Mode, Force Mode
To better understand the concept of impedance, think of a virtual spring connecting the
commanded and actual position. During a move involving contact, the actual position is pulled
along by the commanded position by the virtual spring connecting the two. When the actual
position equals the commanded position the force produced by the virtual spring is close to zero.
But as the distance increases between the two positions, the force increases in proportion to the
stiffness of the spring and the distance. When performing a move involving contact using
impedance mode, this force corresponds to the force that the active-endpoint will impart to a
surface into which it comes in contact.
In Impedance Mode, the arm moves to the position you set. You define compliance by specifying
how stiff the robot should be along which axes. The lower the level of stiffness (impedance), the