Tension control in actuation of multi-joint medical instruments

A method for controlling an instrument system, the instrument system comprising:

• a plurality of actuators,
• an instrument comprising:
• a plurality of joints, and
• a plurality of transmission systems configured to couple the plurality of joints with the plurality of actuators, wherein a first joint of the plurality of joints is distal to a second joint of the plurality of joints, wherein a first transmission system of the plurality of transmission systems passes through the second joint to couple to the first joint, and wherein a second transmission system of the plurality of transmission systems couples to the second joint;
• and
• the method, executing on a control system programmed to control the instrument system, comprising:
• determining a first tension to be applied by the first transmission system;
• determining a first estimate of an interaction response that results at the second joint from applying the first tension by the first transmission system,
• after the determining of the first estimate, determining a second tension to be applied by the second transmission system based on a first set of parameters, the first set of parameters comprising the first estimate, and
• commanding the plurality of actuators such that the first transmission system applies the first tension and the second transmission system applies the second tension.

A non-transitory machine-readable medium comprising a plurality of machine-readable instructions that, when executed by one or more processors associated with an instrument system comprising a plurality of actuators and an instrument, causes the one or more processors to perform a method comprising:

• determining a first tension to be applied by a first transmission system of a plurality of transmission systems of the instrument, wherein the plurality of transmission systems is configured to couple a plurality of joints of the instrument with the plurality of actuators, wherein a first joint of the plurality of joints is distal to a second joint of the plurality of joints, wherein the first transmission system passes through the second joint to couple to the first joint, and wherein a second transmission system of the plurality of transmission systems couples to the second joint;
• determining a first estimate of an interaction response that results at the second joint from applying the first tension by the first transmission system;
• after the determining of the first estimate, determining a second tension to be applied by the second transmission system based on a first set of parameters, the first set of parameters comprising the first estimate;
• and
• commanding the plurality of actuators such that the first transmission system applies the first tension and the second transmission system applies the second tension.