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Ten Nifty Linkage Designs - Core77
(Adrian retweeted this.)
"Very cool videos of linkages. I particularly like the corner cabinet pull-out shelves at the top.”
linkages  kitchen  cabinets  shelves  via:adrian  2017 
july 2017 by handcoding
[1308.4007] Cross Ratios of Quadrilateral Linkages
We discuss the cross-ratio map of planar quadrilateral linkages, also in the case when one of the links is telescopic. Most of our results are valid for a planar quadrilateral linkage with generic lengths of the sides. In particular, we describe the image of cross-ratio map for quadrilateral linkage and planar robot 3-arm.
linkages  kinematics  geometry  dynamical-systems  classification  nudge-targets  consider:feature-discovery 
april 2015 by Vaguery
[1301.7190] A Domain Specific Language for kinematic models and fast implementations of robot dynamics algorithms
Rigid body dynamics algorithms play a crucial role in several components of a robot controller and simulations. Real time constraints in high frequency control loops and time requirements of specific applications demand these functions to be very efficient. Despite the availability of established algorithms, their efficient implementation for a specific robot still is a tedious and error-prone task. However, these components are simply necessary to get high performance controllers.

To achieve efficient yet well maintainable implementations of dynamics algorithms we propose to use a domain specific language to describe the kinematics/dynamics model of a robot. Since the algorithms are parameterized on this model, executable code tailored for a specific robot can be generated, thanks to the facilities available for \dsls. This approach allows the users to deal only with the high level description of their robot and relieves them from problematic hand-crafted development; resources and efforts can then be focused on open research questions.

Preliminary results about the generation of efficient code for inverse dynamics will be presented as a proof of concept of this approach.
representation  DSL  nudge-targets  kinematics  linkages 
april 2013 by Vaguery
Beginner’s guide to ball and socket armatures
Describes making a simple ball-and-socket armature
diy  linkages  armatures 
march 2013 by vosper
Economist Ricardo Hausmann Says U.S. Should Reinvent Manufacturing
January 4, 2013 | MIT Technology Review | By Antonio Regalado.

[ less keen on setting up entire industries at home and instead try to insert themselves into global supply chains. Sometimes this means changing, not just exploiting, their comparative advantage.]

Using complexity theory and trade data, Hausmann looks at what a country is good at making and predicts what types of more valuable items it could produce next.

That sounds plain enough, but the results of Hausmann’s analyses are often surprising. A country with a competitive garment industry might want to move into electronics assembly—both need an industrial zone with quality electrical power and good logistics. A country that exports flowers may find it has the expertise in cold-storage logistics necessary to spark an export boom in fresh produce.
economists  manufacturers  reinvention  competitiveness_of_nations  industrial_zones  competitive_advantage  economies_of_scope  linkages  policymaking  kaleidoscopic  comparative_advantage  supply_chains  value_chains  capabilities  cold_storage 
march 2013 by jerryking
MAKE | Math Monday: Linkages – Four Bars, One Freedom
Math Monday: Linkages – Four Bars, One Freedom, August 06, 2012 at 02:00PM, from MAKE
ifttt  googlereader  MAKE  Math  Monday:  Linkages    Four  Bars  One  Freedom  August  06  2012  at  02:00PM 
august 2012 by designmakecreate
[1205.6213] What nonlinear unimode metamaterials can one get using rigid bars and pivots?
"A complete characterization is given of the possible macroscopic deformations of periodic nonlinear affine unimode metamaterials constructed from bars and pivots. The materials are affine in the sense that their macroscopic deformations are only affine deformations. Unimode means that macroscopically the material can only deform along a one dimensional trajectory in the six dimensional space of invariants describing the deformation (excluding translations and rotations). We show by explicit construction that any continuous trajectory is realizable to an arbitrarily high degree of approximation provided at all points along the trajectory the geometry does not collapse to a lower dimensional one. In particular, we present two and three dimensional dilational materials having an arbitrarily large flexibility window. These are perfect auxetic materials for which a dilation is the only easy mode of deformation."
metamaterials  engineering-design  emergent-design  linkages  nudge-targets 
august 2012 by Vaguery
MAKE | Math Monday: Linkages – An introduction
Math Monday: Linkages – An introduction, July 30, 2012 at 02:01PM, from MAKE
ifttt  googlereader  MAKE  Math  Monday:  Linkages    An  introduction  July  30  2012  at  02:01PM 
august 2012 by designmakecreate
Introduction to the Case Method
(1) Define the central problem. (Problems vs. symptoms, sequence, linkages)
(2) Formulate the alternatives. (3 or 4 are usually sufficient. Include maintenance of the status quo).
(3) Analyze the alternatives. (Uncover the nature, proportion, function, and underlying relationships among a set of variables). Lay out assumptions. Review assumptions to see how dependent conclusions are on the assumptions made. Contingency plans in the case that assumptions don't hold. Opposing arguments addressed? Pros/cons of each alternative.
(4) Recommend a solution. (Make it clear cut. Avoid qualifications)
(5) Specify a plan of action. (Potential reactions)
(6) Prepare contingency plans.
case_studies  business_schools  symptoms  howto  frameworks  problem_framing  problem_solving  linkages  marketing_math  critical_thinking  action_plans  contingency_planning  alternatives  assumptions  argumentation  sequencing 
july 2012 by jerryking

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