Force measurement and force generation in redundant robot manipulators

A method of operating a robot manipulator having a plurality of links interconnected by joints with at least partially redundant degrees of freedom with respect to each other, such that at least a subset of the links of the robot manipulator is movable in a null space without changing a position and/or orientation of a distal end of the robot manipulator, the method comprising:

• detecting, using an operating unit, an input from a user with respect to at least one selected direction of a force and/or a torque at the distal end of the robot manipulator, and transmitting the input as detected;
• receiving, using a control unit, the input from the operating unit;
• determining, using the control unit, components of a transpose of a Jacobian matrix associated with a respective selected direction for a predetermined position and/or orientation of the distal end of the robot manipulator in the null space such that a first metric based on the components satisfies one of a following criteria:
• unequal to zero, greater than a specified limit, or a maximum;
• and
• controlling, using the control unit, the robot manipulator to move the subset of the links in the null space so as to assume a pose according to the components of the transpose of the Jacobian matrix as determined.