Bench Bot v3 Concept Design

Owned by Mark Funderburk
Last updated: May 30, 2024
4 min read

Document Update in Progress

BenchBot v3 is a clean sheet design and will not specifically inherit any design aspects of previous versions.

Project Goals

  • Build a robust and capable robotic system for carrying the image acquisition payload in its execution of the image repository project.

  • Work well in all expected semi-field conditions.

  • Exceed the performance of previous versions of BenchBot.

    • Throughput

    • Reliability

    • Autonomy

  • Be capable of fully automatic operation without an operator on site.

  • Be robust enough to withstand direct exposure to the elements for multiple seasons with reasonable maintenance.

  • Be straightforward to assemble on site with available resources.

    • Field configurable to various site sizes.

    • Not require significant specialized trades on site.

  • Support future payloads in addition to the image acquisition system.

Working Assumptions

  • BenchBot and the Image acquisition system will be treated as separate but connected systems / projects. BenchBot Tool Interface - BenchBot - Confluence (atlassian.net)

  • The system will be based on the Amiga robot from farm-ng.

    • This will save considerable development and manufacturing time by essentially providing a fully electrically / mechanically functional Y axis.

  • PSA (@Mark Funderburk ) will design the gantry structure and X Z motion hardware.

  • BenchBot V3 will use the standard Amiga (as of 2023) hardware + the Brain / navigation kit.

  • There will be a motion controller programmed by PSA between the “Brain” and the motors for real time control of the X and Z axis and will provide an API to the higher level system.

  • PSA software development will be beyond the API level and contained withing the scope of the payload project.

Project Requirements

These requirements are derived from evaluating the performance needs of the Image Acquisition System (IAS) + other applications the BenchBot hardware may be utilized for in the future. However, the IAS is currently the primary payload of the BB and thus the requirements here will be designed to meet the minimum needs of the Image Repository project with additional applications considered where it will not interfere with IAS needs.

The value of many of these requirements is derived from existing semi-field scenarios to be sure we can make the most of the space and resources available.

Summary

Description

Allowable Limits

Status

Summary

Description

Allowable Limits

Status

Axis of Movement

Shall provide 3 integrated axis of movement X, Y, Z.
Y axis movement will be accomplished by the Amiga robot via powered wheels in contact with the operating surface.
X & Z Shall be accomplished with a gantry system.

True

Draft

Tool Head

Shall provide standard electrical & mechanical interface for mounting a toolhead (such as a camera or actuator).

True

Draft

Tool Head Positioning Range

Shall be capable of positioning the tool head anywhere in an operating envelope defined by X, Y, Z dimensions offset by minimum or maximum height from the operating surface.

True

Draft

Tool Head Position Accuracy

Shall be capable of positioning the toolhead in the operating envelope to this degree of accuracy.

+/- 1cm > PA

Draft

Wheel Track Position Accuracy

Shall be capable of positioning the wheel track in the operating envelope to this degree of accuracy.

+/- 10cm > PA

Draft

Tool Head Mass Light

Shall be capable of supporting a tool head of at least this mass in all operating areas.

10kg < M

Draft

Tool Head Mass Heavy

Shall be capable of supporting a tool head of at least this mass in all operating areas.

50kg < M

Draft

Assembly

Shall not require significant specialized labor to assemble onsite.

True

Draft

Gantry Width Configurability

Gantry width shall be field configurable to a specified range without major design changes.

True

Draft

Max Configurable Gantry Width

Gantry shall be configurable and fully functional / structurally sound to at least this width.

W_max >=9m

Draft

Min Configurable Gantry Width

Gantry shall be configurable and fully functional / structurally sound to as little as this width.

W_min <=2m

Draft

Max Configurable Tool Height

Gantry shall be configurable and fully functional / structurally sound to at least this height.

H_max >=3m

Draft

Min Configurable Tool Height

Gantry shall be configurable and fully functional / structurally sound to as little as this height.

H_min <=1.5m

Draft

Z Axis Travel Min

Z axis shall have at least this range of travel

Zt_min <= .5m

Draft

Run Time (Power)

System shall contain sufficient battery capacity or have power tether to ensure all operations can be completed in a single session.

True

Draft

Usage Example

 

Example use case with 20ft wide gantry pictured