Source-linked AI summary
SPROUT: The Open-Source Soft Growing Robot for Search and Rescue
Antonio Alvarez Valdivia, Ciera McFarland, Robert Reeve, Ankush Dhawan, Chad Council, Megan Richardson, Margaret McGuinness, Nathaniel Hanson
TL;DR
Surface-based approaches and existing rescue robots have difficulty reaching victims through tortuous voids, while many vine robots are not suited to disaster-field conditions. SPROUT pairs open-source hardware with a modular ROS 2 stack and field-oriented design. At USAR training sites, it demonstrated growth and traversal tasks, including passage through a 3.81 cm opening.
Problem
Surface-based acoustics and telescoping cameras are inadequate for tortuous paths to victims, while existing rescue robots struggle in complex environments and have seen limited deployments.
Source: §I · p. 1Method
SPROUT combines open-source ruggedized vine-robot hardware, a modular ROS 2 teleoperation and data-acquisition stack, and a vine-body design for field use.
Source: §I · pp. 1–2Results
3.81 cm was the smallest hole diameter SPROUT successfully transited, approximately 50% smaller than the required diameter, during demonstrations that also included growth over rubble and steering through entry paths.
Source: §III · p. 4Takeaways & Limitations
SPROUT’s pneumatic and electrical architecture supports operation without hardwired electrical sources or air compressors, which the authors describe as impractical or unrealistic in the field.
Source: §V · p. 5
Abstract
from arXiv · showhide
Soft robotic systems have long been theorized as ideal candidates for use in search and rescue operations; however, there have been significant barriers to entry in graduating soft robotic systems from the laboratory to the field. To address this gap in replicable, reliable soft robot systems, we present the designs for SPROUT, the Soft Pathfinding Robotic Observation Unit. The system has matured over years of interaction with professional urban search and rescue communities, with the goal of operating in dusty, wet, and isolated conditions. This manuscript contains supplementary material, including code, parts manifests, CAD assemblies, and build instructions to allow the broader robotics research community to build their own SPROUT systems. The modular hardware and ROS 2-based software stack support task-specific payloads and control functions, allowing SPROUT to be adapted for applications beyond search and rescue, including infrastructure inspection and archaeology. Here, we demonstrate SPROUT performing a variety of challenging inspection and traversal tasks in collapsed structure training sites used by first responders. The main project page is available online at https://sprout-mitll.github.io/sprout/.
I. INTRODUCTION
SPROUT addresses the difficulty of reaching victims through tortuous voids and the limited field deployment of existing robots in complex, unstructured environments. It presents an open-source vine robot developed with USAR teams, alongside hardware, software, and vine-body design contributions for field use.
I. INTRODUCTION
- Current surface-based acoustics and telescoping cameras are inadequate for tortuous paths between a surface entry point and a victim’s location.Responders must rapidly assess structural collapses to triage where trapped victims may be located.Source: §I · p. 1
- Existing rescue robots, from tracked vehicles to snake-like designs, struggle in complex, unstructured environments and have seen limited deployments.The paper identifies proprietary designs, dependence on external infrastructure, and fragility as barriers for existing vine robots in disaster regions.Source: §I · p. 1
- Vine robots navigate confined spaces by eversion, with compressed air driving tip extension and steering in a flexible fabric body.Their pressurized textile bodies can deform while carrying tools at the tip; prior applications include in-pipe navigation, archaeology, and USAR training.Source: §I · p. 1
- SPROUT is an easily assembled, portable, encapsulated vine robot engineered with USAR teams and validated in austere environments.The system reflects several years of study and iterative design improvements.Source: §I · p. 1
- The contributions include open-source ruggedized vine-base and compute-platform designs, a modular ROS 2 teleoperation and data-acquisition stack, and a process for high-pressure, high-curvature vine bodies.These contributions are presented to address challenges to soft robotics in disaster response.Source: §I · pp. 1–2
II. DESIGN OF SPROUT
SPROUT integrates pneumatic, mechanical, electrical, and computational systems to grow and steer the vine robot.
II. DESIGN OF SPROUT
- SPROUT links pneumatic, mechanical, electrical, and computational systems to support vine growth and steering.The system interconnection is shown in Fig. 2, and a full CAD assembly is shown in Fig. 3.Source: §II · p. 2
- The system architecture connects pneumatic and electromechanical components for portable teleoperation.Pneumatic power can come from an air compressor or portable air tank, and multiple controller models can teleoperate the robot.Source: §II · p. 2
- A full CAD assembly documents the interconnected system components.The architecture is illustrated in Fig. 2 and the assembly in Fig. 3.Source: §II · p. 2
A. Vine Base
The SPROUT vine base retains the open-source base’s deployment and retraction principle while adding changes intended to improve assembly, reliability, safety, and portability.
A. Vine Base
- The base deploys the vine by pressurizing its chamber while a motorized spool unwinds a retraction tendon, and retracts it by winding the tendon back in.Its main components are a cylindrical pressure chamber, spool, tendon, outlet tube, and acrylic side plates.Source: A. Vine Base · p. 2
- The redesigned reel core uses threaded inserts to fasten the acrylic plates and a concave groove to guide the tendon toward the spool center.The groove reduces the tendon’s tendency to accumulate near the spool edges.Source: A. Vine Base · p. 2
- 12.7 mm acrylic retaining plates, secured with threaded rods, allow higher-pressure operation without risk of the Quik caps separating.Shoulder strap and carrying handles facilitate transport of the assembled system.Source: A. Vine Base · p. 2
- The supplementary CAD package includes the complete modified vine-base assembly for reproduction alongside the original Vine Robots construction instructions.The base retains the original geometry and operating principle while incorporating modifications for assembly, reliability, safety, and portability.Source: A. Vine Base · p. 2
B. Compute Box
SPROUT combines a portable, weatherproof compute enclosure with a ROS 2 stack designed for quick setup, teleoperation, and extensibility.
B. Compute Box
- The weatherproof compute box consolidates computing, power distribution, embedded control, and pneumatic hardware in an enclosure installed on the vine base.Its removable electronics plate carries the compute, motor-drive, power-distribution, and electropneumatic hardware; an interface plate supports peripherals, display, and emergency-stop button.Source: B. Compute Box · p. 2, Figure 3 · p. 3
- An external 18-V battery powers the compute box, with DC-DC converters supplying auxiliary and compute voltage rails and independently fused power branches isolating subsystem faults.The supplementary materials provide component specifications, wiring diagrams, connector pinouts, enclosure preparation, and assembly procedures.Source: B. Compute Box · p. 2
C. Software Stack
- A Jetson Orin Nano handles higher-level computation and joystick processing, while an Arduino Uno interfaces with the reel motor driver and electronic pressure regulators.The devices communicate over serial, and the custom Arduino shield exposes additional analog and digital pins for sensors and low-level hardware.Source: C. Software Stack · p. 2
- The ROS 2 Humble stack launches from power-on and organizes software as nodes publishing standard ROS 2 and custom vine-hardware messages.The custom Arduino shield supports additional sensors and low-level hardware, including the joystick demonstrated in.Source: C. Software Stack · p. 2
D. Pneumatic Power
SPROUT primarily uses SCBA air tanks for pneumatic power, with an air compressor as an alternative.
D. Pneumatic Power
- A 15.3 MPa SCBA tank is regulated to 207 kPa for the base pressure regulator, providing one hour of continuous operation before a tank swap.The backpack-mounted tank is routinely carried by first responders; quick-disconnect hoses allow switching to an air compressor if needed.Source: D. Pneumatic Power · p. 3
E. Control Paradigms
A single joystick teleoperates steering, growth and retraction speed, and main-body pressure. SPROUT offers two controller options, with other ROS 2 peripherals also integrable.
E. Control Paradigms
- Three circumferential series pouch motors shorten when pressurized, curving the vine body toward the actuated side.Joystick motion adjusts pressure supplied to the motors to steer in a plane perpendicular to the everted body.Source: E. Control Paradigms · p. 3, Figure 4 · p. 3
- The joystick controls growth and retraction speed and pressure within the main vine body.Standard ROS 2 messages allow other control peripherals to be integrated.Source: E. Control Paradigms · p. 3
- SPROUT supports a PlayStation 5 controller or a Wired Tactical controller, which is preferred for its IP66 rating against dust and moisture.The PlayStation 5 controller is the cost-effective alternative.Source: E. Control Paradigms · p. 3
F. Vine Construction
SPROUT’s integrated-pouch vine body combines its main chamber and steering actuators in one fabricated structure. This design reduces material and packed volume while balancing growth and steering performance.
F. Vine Construction
- The integrated-pouch body combines the main chamber and three longitudinal steering actuators, forming a 7.62 cm tube that achieved a 137 kPa burst pressure.The TPU-coated fabric is folded, heat-sealed, and shaped with longitudinal body seals and transverse actuator-pouch seals.Source: F. Vine Construction · p. 3
- Compared with exterior pouches, the integrated design uses less fabric and reduces collapsed-body volume, allowing a longer robot to fit in the base.Integrated-pouch robots require pouch pressure to exceed main-chamber pressure before appreciable steering, but can reach greater maximum curvature than exterior-pouch robots at higher pressure ratios.Source: F. Vine Construction · p. 3
- The rubble-pile figure depicts growth through a 3.81 cm steel-plate hole, about half the nominal 7.62 cm body diameter.Its panels also show traversal through rebar and entry into voids and cluttered openings.Source: Figure 5 · p. 4
- The fabrication procedure for the integrated-pouch body is included in the supplementary documentation.The figure also depicts traversal through rebar, cluttered entry, and void spaces.Source: F. Vine Construction · p. 4, Figure 5 · p. 4
III. DEMONSTRATION
Field trials at an engineered collapsed-structure training site tested SPROUT’s growth, steering, aperture passage, and durability. The 4 m body traversed varied rubble and small openings, with only a minor puncture after five hours.
III. DEMONSTRATION
- At 10.3 kPa chamber pressure, SPROUT grew at 0.11 m/s and traversed flat, inclined, and complex rubble surfaces.Trials also tested vertical growth into voids and steering through large and jagged, nonlinear openings.Source: §III · p. 4
- SPROUT grew up a pile and entered a 6.4 cm hole used by USAR crews for manual void inspection.The hole permits inspection with search cameras.Source: §III · p. 4
- The smallest successfully transited steel-plate hole was 3.81 cm in diameter, approximately 50% smaller than the required diameter.The tests also deployed the robot across organic material, broken concrete, steel rebar, and sheet metal.Source: §III · p. 4
- After five hours on abrasive and sharp surfaces, the vine body had only a minor puncture and could be replaced to continue exploration.The trials were conducted at a Massachusetts Task Force 1 engineered collapsed-structure training site with a 4 m body.Source: §III · p. 4
IV. SYSTEM EXTENSIBILITY
SPROUT supports multiple vine-body configurations and can be adapted with additional hardware and sensing options.
IV. SYSTEM EXTENSIBILITY
- Both integrated- and exterior-pouch vine bodies interface with the base through the main pressure line and three independently controlled pouch motor lines.The platform is not restricted to the integrated-pouch body used here.Source: §IV · p. 4
- Removable electronics plates, internal space, and existing power and communication interfaces accommodate additional sensing, actuation, or control hardware.Source: §IV · p. 5
- SPROUT supports tip-mounted sensors and distributed sensing nodes along the vine body.Source: §IV · p. 5
V. CONCLUSION
SPROUT is an open-source, open-hardware vine robot designed for field use, with a weatherproof compute box and independent pneumatic and electrical operation. The supplementary materials include documentation, CAD, electronics, and software files for building and configuring the system.
V. CONCLUSION
- SPROUT combines a weatherproof compute box with pneumatic and electrical architecture for operation without hardwired electrical sources or air compressors.Its ROS 2-based software stack supports data logging and novel control paradigms.Source: §V · p. 5
- The authors anticipate SPROUT will serve as a springboard for advances in soft robotics in dirty and dangerous conditions.Source: §V · p. 5
SUPPLEMENTARY INFORMATION
- The supplementary materials provide step-by-step build instructions, photos, a bill of materials, CAD models, Arduino shield design files, and software bootstrap scripts.Source: SUPPLEMENTARY INFORMATION · p. 5