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EP-4305279-B1 - ACTIVE REELING AND STEERING CONTROL OF AN EVERSION/VINE ROBOT

EP4305279B1EP 4305279 B1EP4305279 B1EP 4305279B1EP-4305279-B1

Inventors

  • HAGGERTY, DAVID
  • HAWKES, Elliot

Dates

Publication Date
20260506
Application Date
20220308

Claims (15)

  1. A soft vine robot, comprising: a main body (130) configured as a tube inverted back inside itself to define a pressure channel, such that when the channel is pressurized, the main body everts, and inverted material of the main body everts and passes out of a tip at a distal end of the main body; a reeling mechanism controlled by a reeling motor (120), the reeling mechanism being within the tube and being configured to actively feed the inverted material to provide or assist eversion and to actively retract extended material of the main body back; and control and communications electronics to control the reeling motor.
  2. The soft vine robot of claim 1, wherein the reeling mechanism comprises storage configured to store the inverted material.
  3. The soft vine robot of any previous claim, comprising a controlled pressure source to pressurize the pressure channel.
  4. The soft vine robot of any previous claim, wherein the reeling mechanism cylindrical proximal housing for the control and communications electronics.
  5. The soft vine robot of claim 4, wherein the reeling mechanism comprise a set of rollers driving by the reeling motor, the rollers being engaged with inverted body passing between the rollers.
  6. The soft vine robot of claim 5, comprising central opening at a distal end of the reeling mechanism that receives the inverted body into the rollers.
  7. The soft vine robot of any previous claim, wherein the reeling mechanism comprises a steering mechanism with a bending axis controlled by a steering motor.
  8. The soft vine robot of claim 7, wherein the reeling mechanism comprises a proximal base frame that extends from the cylindrical proximal electronics housing.
  9. The soft vine robot of claim 8, wherein the reeling mechanism comprises a distal motor support frame pivotally connected to the proximal base frame via an axis pin, and wherein the steering motor and reeling motor are mounted on the base frame.
  10. The soft vine robot of claim 9, wherein the distal motor support frame comprises a reeling spool driven by the reeling motor around which the inverted body spools.
  11. The soft vine robot of claim 10, comprising spacing around the reeling spool to accommodate the body when it is fully inverted and stored on the reeling spool.
  12. The soft vine robot of any of claims 9-11, comprising a distal cylindrical tip at the end of the distal motor support frame, the distal cylindrical tip comprising a central opening to receive inverted material onto the reeling spool.
  13. The soft vine robot of any previous claim comprising a plurality of steering and/or reeling mechanisms and/or a camera at a distal tip of the robot.
  14. A method for controlling eversion and inversion of a soft vine robot according to any of the previous claims, the method comprising: pressuring a channel of a main body (130) configured as a tube inverted back inside itself; actively supplying eversion or inversion forces to the main body via rollers (326) or a spool (124) activated by a reeling motor (120) contained within the channel; and balancing channel pressure and eversion or inversion forces with a pressure controller and the reeling motor, and optionally steering the main body about a pivot structure within the main body with a steering motor (118) within the main body.
  15. The method of claim 14, comprising extend the tip of the main body vie everting the main body from force supplied by the rollers or the spool with low pressure i.e., pressure insufficient to itself cause extension/eversion.

Description

FIELD A filed of the invention is everting robots, also referred to as vine robots. BACKGROUND Vine robots are formed of soft materials and evert in response to fluid pressure. Specifically, a vine robot extends from its tip by everting or unfurling new material, driven by internal body pressure. See, e.g. Hawkes et al., US Patent 2019217908. Vine robots typically store new body material in a reel at their base, which material is unreeled as the robot is extended and everts in response to fluid pressure passing it through the core of the robot to the tip. Made of a thin-walled membrane inverted inside itself, these robots "grow" when inflated, passing new material through the body to emerge at the tip to achieve extension. Their bodies do not move relative to their surroundings. Some vine robots achieve active steering by selectively lengthening or shortening one side of the body being extended. While this approach to steering and material storage lends itself to a fully soft device, it has three key limitations: (i) internal friction of material passing through the core of the robot limits its length in tortuous paths, (ii) body buckling as the robot's body material is re-spooled at the base can prevent retraction, and (iii) constant curvature steering limits the robot's poses and object approach angles in a given workspace. Several designs have been proposed to overcome the constant curvature steering limits. One design is based upon tendon actuation coupled with pneumatic shape locking. S. Wang, R. Zhang, D. A. Haggerty, N. D. Naclerio, and E. W. Hawkes, "A dexterous tip-extending robot with variable-length shape-locking," in 2020 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2020, pp. 9035-9041. Another design used discrete, reversible body stiffness modulation. B. H. Do, V. Banashek, and A. M. Okamura, "Dynamically reconfigurable discrete distributed stiffness for inflated beam robots," in 2020 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2020, pp. 9050-9056. An additional design used mechanical interlocks. W. Hawkes, L. H. Blumenschein, J. D. Greer, and A. M. Okamura, "A soft robot that navigates its environment through growth," Science Robotics, vol. 2, no. 8, p. eaan3028, 2017. Another used active and programmable heat sealing. Y. Satake, A. Takanishi, and H. Ishii, "Novel growing robot with inflatable structure and heat-welding rotation mechanism," IEEE/ASME Transactions on Mechatronics, vol. 25, no. 4, pp. 1869-1877, 2020. These designs fail to provide flexible active control of growth direction and/or materially alter the nature of vine robot growth. SUMMARY OF THE INVENTION A preferred embodiment provides a soft vine robot. The robot includes a main body configured as a tube inverted back inside itself to define a pressure channel, such that when the channel is pressurized, the main body everts, and inverted material of the main body everts and passes out of a tip at a distal end of the main body. A reeling mechanism is controlled by a reeling motor, the reeling mechanism being within the tube and being configured to actively feed the inverted material to provide or assist eversion and to actively retract extended material of the main body back. Control and communications electronics control the reeling motor. In a preferred embodiment, the reeling mechanism includes a steering mechanism with a bending axis controlled by a steering motor. A method for controlling eversion and inversion of a soft vine robot includes pressuring a channel of a main body configured as a tube inverted back inside itself. The method includes actively supplying eversion or inversion forces to the main body via rollers or a spool activated by a reeling motor contained within the channel. Channel pressure and eversion or inversion forces are balanced with a pressure controller and the reeling motor. In a preferred embodiment, the main body is steerd by pending a pivot structure within the main body with a steering motor within the main body. BRIEF DESCRIPTION OF THE DRAWINGS FIGs. 1A-1C illustrate a preferred steering and reeling device and soft vine robot;FIGs. 2A-2G illustrate operation of the FIGs. 1A-1C robot;FIG. 3 illustrates a preferred vine robot with multiple steering and reeling devices;FIG. 4 illustrates a preferred active reeling device and soft vine robot;FIG. 5 illustrates a preferred soft vine robot with an active reeling device and a camera; andFIG. 6 is data comparing a present active reeling device robot to a conventional base reeling soft vine robot in terms of required pressures to grow as a function of path angle of growth. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments provide a vine robotic device with point deformation through a bending motor on the device that provides for steering and reeling. Instead of reeling from the base like prior vine robots, a preferred vine robot can reel from the tip using an onboard reeling motor. An a