Variable-rigidity device, control device, and method for controlling actuator

Patent metadata

Field	Value
Publication number	US-12108932-B2
Application number	US-202117408935-A
Country	US
Kind code	B2
Filing date	Aug 23, 2021
Priority date	Feb 27, 2019
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

Abstract

A variable-rigidity device includes a tubular member including a plurality of high-rigidity portions and low-rigidity portions arranged along a longitudinal axis, a core member arranged on an inner side of the tubular member and including a plurality of high-rigidity core portions and low-rigidity core portions; and an actuator configured to relatively move the core member with respect to the tubular member, in which the actuator is configured to cause a first force to repeatedly fluctuate with a passage of time, the first force causing the core member to relatively move with respect to the tubular member in an axial direction along the longitudinal axis.

First claim

What is claimed is:

1. A variable-rigidity device comprising:
a tubular member including a plurality of first tube parts and second tube parts arranged along a longitudinal axis, a rigidity of the first tube parts being higher than a rigidity of the second tube parts;
a core member arranged on an inner side of the tubular member and including a plurality of first core parts and second core parts, a rigidity of the first core parts being higher than a rigidity of the second core parts;
an actuator configured to relatively move the core member with respect to the tubular member; and
a controller configured to control the relative movement by the actuator;
wherein the controller is configured to cause a first force to repeatedly fluctuate with a passage of time, the first force causing the core member to relatively move with respect to the tubular member in an axial direction along the longitudinal axis.

2. The variable-rigidity device according to claim 1 , wherein a direction in which the first force is applied is caused to fluctuate with the passage of time.

3. The variable-rigidity device according to claim 1 , wherein the controller is configured to cause a second force to repeatedly fluctuate with the passage of time, the second force causing the core member to relatively move with respect to the tubular member in a rotation direction about the longitudinal axis.

4. The variable-rigidity device according to claim 3 , wherein the rotation direction is repeatedly reversed with the passage of time.

5. The variable-rigidity device according to claim 3 , wherein the controller is configured to control the actuator:
to move the core member at a predetermined constant speed with respect to the passage of time when relatively moving the core member with respect to the tubular member in the axial direction along the longitudinal axis, and
to cause the second force to repeatedly fluctuate with the passage of time when the controller detects that a load of the actuator is greater than a threshold during execution of the operation.

6. The variable-rigidity device according to claim 1 , wherein the controller is configured to control the actuator:
to move the core member at a predetermined constant speed with respect to the passage of time when relatively moving the core member with respect to the tubular member in the axial direction along the longitudinal axis, and
to cause the first force to repeatedly fluctuate with the passage of time when the controller detects that a load of the actuator is greater than a threshold during execution of the operation.

7. A control device comprising a processor including at least one piece of hardware, wherein the processor is configured to, when driving an actuator configured to relatively move a core member with respect to a tubular member in a direction of a longitudinal axis, the core member being arranged on an inner side of the tubular member and including a plurality of first core parts and second core parts, a rigidity of the first core parts being higher than a rigidity of the second core parts, the tubular member including a plurality of first tube parts and second tube parts arranged along the longitudinal axis, a rigidity of the first tube parts being higher than a rigidity of the second tube parts, cause a first force to repeatedly fluctuate with a passage of time, the first force causing the core member to relatively move with respect to the tubular member in an axial direction along the longitudinal axis.

8. The control device according to claim 7 , wherein a direction in which the first force is applied is caused to fluctuate with the passage of time.

9. The control device according to claim 7 , wherein the processor is configured to cause a second force to repeatedly fluctuate with h passage of time, the second force causing the core member to relatively move with respect to the tubular member in a rotation direction about the longitudinal axis.

10. The control device according to claim 9 , wherein the rotation direction is repeatedly reversed with the passage of time.

11. A method for controlling an actuator, comprising:
detecting a load of h actuator when driving the actuator, the actuator being configured to relatively move a core member with respect to a tubular member in a direction of a longitudinal axis, the core member being arranged on an inner side of the tubular member and including a plurality of first core parts and second core parts, a rigidity of the first core parts being higher than a rigidity of the second core parts, the tubular member including a plurality of first tube parts and second tube parts arranged along the longitudinal axis, a rigidity of the first tube arts being higher than a rigidity of the second tube parts;
when the load is greater than a predetermined threshold, causing a first force to repeatedly fluctuate with a passage of time, the first force causing the core member to relatively move with respect to the tubular member in an axial direction along the longitudinal axis; and
when the load is not greater than the predetermined threshold, moving the core member at a predetermined constant speed with respect to the passage of time.

Assignees

• Olympus Corp

Inventors

• Kugo Tomoyuki
• Takahashi Takeshi
• KITANAKA Tomohiro

Classifications

• A61B1/0055

  Constructional details of insertion parts, e.g. vertebral elements · CPC title

• A61B1/0051

  with controlled bending of insertion part · CPC title

• A61B1/00006

  of control signals · CPC title

• F16C1/12

  Arrangements for transmitting movement to or from the flexible member · CPC title

• F16C1/20

  Construction of flexible members moved to and fro in the sheathing · CPC title