Resonance detection and resolution

A method for controlling a following error in a robotic system that moves a tool at a velocity along a predefined path defined by an inputted set of vertices, the following error being controlled to be less than a tolerable error allowance, the method comprising:

• assigning a vertex velocity to each vertex, the vertex velocity being selected so that the resultant following error when the tool negotiates the vertex at its assigned vertex velocity is less than the tolerable error allowance;
• identifying a subset of resonant vertices from the inputted set of vertices, the resonant vertices each having a neighboring vertex for which the resultant following error when the tool negotiates both the vertex and its neighboring vertex at the assigned vertex velocities might exceed the tolerable error allowance;
• and
• assigning a reduced vertex velocity to each vertex in the subset of resonant vertices, the reduced vertex velocity being selected so that the resultant following error when the tool negotiates both the vertex and its neighboring vertex at the reduced vertex velocities is less than the tolerable error allowance.

A method for detecting and resolving resonance in a robotic system that moves a tool a velocity along a predefined path defined by an inputted set of vertices, each of the vertices having a vertex velocity associated with it, the method comprising:

• identifying a subset of suspect vertices from the inputted set of vertices;
• identifying a subset of resonant vertices from the subset of suspect vertices;
• adjusting vertex velocities that both exceed the low-limit velocity and are associated with identified resonant vertices;
• identifying pairs of resonant vertices from the subset of resonant vertices for which a tool travel time between the pair of resonant vertices is less than a resonance window period when the velocity of the tool is controlled according to a nonresonant velocity profile;
• reclassifying as resonant vertices those vertices in the inputted set of vertices that lie between the identified pairs of resonant vertices;
• and
• controlling movement of the tool according to a resonant velocity profile when traveling between the identified pairs of resonant vertices.

A method for controlling movement of a tool in a robotic system that moves the tool at a velocity along a path defined by an inputted set of vertices, the method comprising:

• assigning a vertex velocity for each of the inputted vertices;
• identifying a subset of resonant vertices from the inputted set of vertices;
• reducing the vertex velocity associated with each identified resonant vertex having an associated vertex velocity that exceeds a predefined low-limit velocity;
• and
• controlling movement of the tool based upon the reduced vertex velocities associated with each vertex in the inputted set of vertices.