Continuum robot and control method for continuum robot, and recording medium

A continuum robot comprising:

• a plurality of bendable portions which are provided in series in a lengthwise direction and each of which is bendable;
• at least one processor that executes instructions to:
• cause the plurality of bendable portions to perform forward movement or backward movement in the lengthwise direction, and
• cause each of the bendable portions in the plurality of bendable portions to bend to change an attitude of the bendable portion;
• and
• at least one memory configured to store the attitude with regard to each of the bendable portions in the plurality of bendable portions,
• wherein the at least one processor is further configured to perform, when the forward movement or the backward movement is caused, in a case where a first attitude that is an attitude of at least one bendable portion in the plurality of bendable portions deviates to a predetermined extent or more from a second attitude that is an attitude of the at least one bendable portion which is stored in the at least one memory, switching or continuous transition from first control for changing the attitude into a specified attitude to second control for changing the attitude following an external force, and
• wherein the at least one processor further applies, as a condition for reversion from the second control to the first control, a situation where the forward movement of positions of the plurality of bendable portions is performed by a predetermined distance or the backward movement of positions of the plurality of bendable portions is performed by a predetermined distance since the switching or continuous transition from the first control to the second control.

A control method for a continuum robot including a plurality of bendable portions which are provided in series in a lengthwise direction and each of which is bendable, at least one processor that executes instructions to (1) cause the plurality of bendable portions to perform forward movement or backward movement in the lengthwise direction, and (2) cause each of the bendable portions in the plurality of bendable portions to bend to change an attitude of the bendable portion, and at least one memory configured to store the attitude with regard to each of the bendable portions in the plurality of bendable portions, the control method comprising:

• performing, when the forward movement or the backward movement is detected, in a case where a first attitude that is an attitude of at least one bendable portion in the plurality of bendable portions deviates to a predetermined extent or more from a second attitude that is an attitude of the at least one bendable portion which is stored in the at least one memory, switching or continuous transition from first control for changing the attitude into a specified attitude to second control for changing the attitude following an external force, and then
• performing switching or continuous transition from the second control to the first control, when (1) the backward movement of positions of the plurality of bendable portions is performed since the switching or continuous transition from the first control to the second control and (2) a situation where a deviation between the first attitude and the second attitude is equal to or lower than a threshold in a bendable portion positioned on a most proximal side out of at least one bendable portion in which the second control is executed is met.