Simulation Construction Set

Simulation Construction Set

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›Implementing Closed-Chain Mechanisms Using External Force Points

Getting Started

  • Quick Start
  • Requirements
  • Using IHMC Open Robotics Software .jar releases with Maven/Gradle
  • Building .jars
  • Depending Directly on the Source

Using the SCS GUI

  • Running a simulation
  • Changing the Camera Settings
  • SCS Variables
  • Graphing Variables
  • Simulation Replay
  • Data Buffer
  • Exporting Data
  • Export Snapshots and Video of the 3D View

Creating a New Simulation

  • Summary
  • Create a New Project
  • SimplePendulumSimulation.java
  • SimplePendulumRobot.java
  • Run the simulation

Adding Control to a Simulation

  • Summary
  • Adding control to a simulation
  • Run the simulation

Creating Links

  • Summary
  • Creating Links
  • Run the Simulation

Creating Robot with Multiple Joints

  • Summary
  • Create a New Package
  • Mobile Simulation
  • Initial Variables in MobileRobot Class
  • MobileRobot Class Description

Ground Contact Modeling

  • Summary
  • Create a New Package
  • Create a New Class FallingBrickSimulation
  • Create a New Class FallingBrickRobot
  • Create a New Class WavyGroundProfile
  • Description and Analysis

Implementing Closed-Chain Mechanisms Using External Force Points

  • Summary
  • Implementing Closed-Chain Mechanisms
  • FlyballGovernorSimulation Class
  • FlyballGovernorRobot Class
  • FlyballGovernorSimpleClosedLoopConstraintController Class
  • FlyballGovernorCommonControlParameters Class
  • Description and Analysis

Implementing Closed-Chain Mechanisms

Currently, the Simulation Construction Set only allows for systems which have a tree structure of Joints and Links. However, Closed-Chain Mechanisms, like 4 bar linkages for example, can be implemented using ExternalForcePoints. Two ExternalForcePoints can be placed at two different points on the system which are constrained to stay together. A "glue" force can then be computed based on the error in position between the two points. That glue force can then be applied to the ExternalForcePoints in equal and opposite directions. In this tutorial, you'll see how to construct a Flyball Governor simulation, like the one shown in Figure 8. Since this is a closed-loop mechanism, we use ExternalForcePoints to hold the cross links to the rotating blue cylinder.

Figure 8

Create a new package called flyballGovernor

The package should be located within your us.ihmc.exampleSimulations package.

← SummaryFlyballGovernorSimulation Class →
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