Difference between revisions of "DIY: Percevarence grass cutter"

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== Introduction ==
== Introduction ==
Make a mower that resembles Percevarence: Six wheels with rocker-boogie suspension.


Designed for slow motion (10 cm/s).
Designed for slow motion (10 cm/s).


== Theory ==
== Theory ==
=== Naming conventions ===
* 4WD or 4x4: Four wheel drive.
* AWD: All wheed drive
* 6x4: three axles, two of which provide torque to two axle ends each.
* 6WD or 6x6. H-drive.
https://en.wikipedia.org/wiki/Steering; see eg Ackermann steering.
[https://en.wikipedia.org/wiki/Differential_steering Differential steering]. Turning radius. [https://en.wikipedia.org/wiki/Differential_wheeled_robot Differential wheeled robots]. Kinematics of differential drive robots. https://rossum.sourceforge.net/papers/DiffSteer/DiffSteer.html
https://thef1clan.com/2020/09/21/vehicle-dynamics-the-kinematic-bicycle-model/
The kinematics of mobile robots is clearly described in Robotics.SE article https://robotics.stackexchange.com/questions/8911/how-to-find-kinematics-of-differential-drive-caster-robot
Mathworks www site contains a good and simple reference for mobile robot kinematics equations, see https://www.mathworks.com/help/robotics/ug/mobile-robot-kinematics-equations.html
Skid steer dynamics is considered in the following paper https://www.joydeepb.com/Publications/icra2019_skid_steer.pdf
A detailed description of six wheeled robots made using Arduino on Instructables https://www.instructables.com/Remote-Controlled-6WD-All-Terrain-Robot/


=== Rocker-bogie ===
=== Rocker-bogie ===
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==== Differential gearbox ====  
==== Differential gearbox ====  


====Differential bar ====
====Differential bar (linkage) ====




http://alicesastroinfo.com/2012/07/mars-rover-rocker-bogie-differential/
http://alicesastroinfo.com/2012/07/mars-rover-rocker-bogie-differential/


=== "Dynamic Rocker-Boogie" ===


=== Dynamic Rocker-Boogie ===
=== Stress and tension (different parameters) ===
 
Approximate the stress and forces on the different parts of the rocker--boogie joints.
 
=== Wheel motors ===
 
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2510209.m570.l1313&_nkw=1500W+threaded+rear+&_sacat=0
 
https://zjmy-lu.en.made-in-china.com/
 
https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=10inch+300W+36V+Brushless+Motor+&selectedTab=product_en and https://www.alibaba.com/product-detail/DC-brushless-10-Inch-single-shaft_1600164251056.html?spm=a2700.galleryofferlist.normal_offer.d_image.a61d69d3yQtzhj&s=p
 
https://duckduckgo.com/?q=wheel+with+1.5kW+brushless+motor&t=ffab&iax=images&ia=images&iai=https%3A%2F%2Fsc02.alicdn.com%2Fkf%2FHTB1cHvvajzuK1RjSspeq6ziHVXay%2F233713178%2FHTB1cHvvajzuK1RjSspeq6ziHVXay.jpg
 
No axle motors.
 
Wattage. 500W?


== References ==
== References ==
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=rocker+bogie+mechanism+working+principle&btnG= First three (3) pages 2022.05.13.


https://studylib.net/doc/25318418/irjet-design-and-fabrication-of-rocker-bogie-mechanism-us...
https://studylib.net/doc/25318418/irjet-design-and-fabrication-of-rocker-bogie-mechanism-us...
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Design Optimization of a Mars Rover’s Rocker-Bogie Mechanism using Genetic Algorithms. Franziska Ullrich, Ali Haydar Gokto ¨ gan, Salah Sukkarieh
Design Optimization of a Mars Rover’s Rocker-Bogie Mechanism using Genetic Algorithms. Franziska Ullrich, Ali Haydar Gokto ¨ gan, Salah Sukkarieh


https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=rocker+bogie+mechanism+working+principle&btnG=
ANALYSIS AND SIMULATION OF A ROCKER-BOGIE EXPLORATION ROVER
Hervé Hacot, Steven Dubowsky, Philippe Bidaud2. https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.33.9327&rep=rep1&type=pdf
 
Instrumented Rocker-Bogie Chassis Design and Net Traction Estimation. Timothy P. Setterfield. https://curve.carleton.ca/system/files/etd/e6ba9694-33ac-4a8d-8db1-ac548cce2220/etd_pdf/f176d20fd9fd9de537fea2656f5a39da/setterfield-instrumentedrockerbogiechassisdesignandnet.pdf
 
 
 
 
 


<youtube>E_6e71BJOzM</youtube>
<youtube>E_6e71BJOzM</youtube>
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<youtube>bP7p5Bd2d50</youtube>
<youtube>bP7p5Bd2d50</youtube>
<youtube>2FbW_kVYcl0</youtube>
https://duckduckgo.com/?q=wheel+motor+for+dixie+chopper+mower&t=ffab&iax=images&ia=images&iar=images&iai=https%3A%2F%2Fqspowerequipment.com%2Fproduct%2F2021-dixie-chopper-blackhawk-hp-2660kwe%2FThumb-2.jpg&pn=1

Latest revision as of 12:48, 4 November 2022

Introduction

Make a mower that resembles Percevarence: Six wheels with rocker-boogie suspension.

Designed for slow motion (10 cm/s).

Theory

Naming conventions

  • 4WD or 4x4: Four wheel drive.
  • AWD: All wheed drive
  • 6x4: three axles, two of which provide torque to two axle ends each.
  • 6WD or 6x6. H-drive.

https://en.wikipedia.org/wiki/Steering; see eg Ackermann steering.

Differential steering. Turning radius. Differential wheeled robots. Kinematics of differential drive robots. https://rossum.sourceforge.net/papers/DiffSteer/DiffSteer.html

https://thef1clan.com/2020/09/21/vehicle-dynamics-the-kinematic-bicycle-model/

The kinematics of mobile robots is clearly described in Robotics.SE article https://robotics.stackexchange.com/questions/8911/how-to-find-kinematics-of-differential-drive-caster-robot

Mathworks www site contains a good and simple reference for mobile robot kinematics equations, see https://www.mathworks.com/help/robotics/ug/mobile-robot-kinematics-equations.html

Skid steer dynamics is considered in the following paper https://www.joydeepb.com/Publications/icra2019_skid_steer.pdf

A detailed description of six wheeled robots made using Arduino on Instructables https://www.instructables.com/Remote-Controlled-6WD-All-Terrain-Robot/

Rocker-bogie

https://en.wikipedia.org/wiki/Rocker-bogie

The tension, forces on the single joint?

Differential Joint

The two rockers connect to each other and to the body through a differential. It keeps the body level. When one rocker goes up, the other rocker goes down, and the body angle is halfway between the angles of the two rockers.

Differential gearbox

"Dynamic Rocker-Boogie"

Stress and tension (different parameters)

Approximate the stress and forces on the different parts of the rocker--boogie joints.