tharp

Tharp is an inverse kinematics solver and robot manager designed to work with Johnny-Five. It makes the hard things easy. Check out this video highlighting Tharp's performance.

Installation

npm install tharp

Documentation

Tharp documentation can be found in the wiki.

Example

// This is a simple excerpt, illustrating the configuration// of robot with two legsvarfive=require("johnny-five"),tharp=require("tharp");varboard=newfive.Board().on("ready",function(){/* === Begin robot configuration === */// Tharp.Chain() wraps our actuators and adds properties// that define the kinematic system. The "chainType" property defines// the joint/link configuration.varleftLeg=newtharp.Chain({constructor: five.Servos,chainType: "ZYY",origin: [4.25,0.15,2.875],links: [2.6,7.6125,10.4],actuators: [{pin:40,offset: 24,startAt: 0,range: [0,90]},{pin:39,offset: 87,startAt: 78,range: [-80,78]},{pin:38,offset: 165,invert: true,startAt: -140,range: [-160,-10]}]});varrightLeg=newtharp.Chain({constructor: five.Servos,chainType: "ZYY",origin: [-4.25,0.15,2.875],links: [2.6,7.6125,10.4],actuators: [{pin:27,offset: -31,startAt: 180,range: [90,180]},{pin:26,offset: -77,startAt: 102,range: [110,260]},{pin:25,offset: -176,invert: true,startAt: 320,range: [180,340]}]});// Robot() wraps our chains, gives us a place to orient the// robot chassis and ensures that all chains can be rendered// before rendering the entire robot movementvarrobot=newtharp.Robot({chains: [rightLeg,leftLeg]});/* === End robot configuration === */// Now we can orient the chassisrobot.orientation({pitch: 0.1,roll: -0.08,yaw: -0.13});robot.offset([1,-1,-0.2]);// And position our end effectorsrightLegChain.solve({position: [8.25,2.5,-5.0]});leftLegChain.solve({position: [-8.25,-2.25,-5.0]});// Move everythingrobot.render();});

Breaking Changes

• 1.0.0 Swapped Y and Z axes to better match best practices. Renamed "CoxaY-FemurZ-TibiaZ" chain type to "ZYY".
• 2.0.0 Changes segments to an array since part names are arbitrary. One person's "coxa" is another person's "hip" and then another person's "shoulder".
• 3.0.0 Changes segments to links to reflect the proper name.