Available sample controllers

In this page you will find a list of all available sample controllers provided with the framework, along with a brief description of how to run them and what to expect. More complex controllers will be further detailed in their own tutorial page.

Posture

The Posture controller (see online demonstration) is the simplest controller in the framework. It adds the following tasks and constraints to the QP solver.

Tasks

• mc_tasks::PostureTask: Make each of the robot’s DoF target a given joint position. By default this controller will target the current robot encoder values when available, or the default stance for that robot otherwise (mc_rbdyn::RobotModule::stance()). Joints can be moved through the joint sliders in the GUI (Tasks -> posture_jvrc1 -> Target).

Constraints

• mc_solver::ContactConstraint: A controller must always have a contact constraint, but it can have an empty set of contacts.
• mc_solver::KinematicsConstraint: Joint limits constraint.
• mc_solver::CollisionsConstraint: Self-collision avoidance constraint.
• mc_solver::CompoundJointConstraint: Handle joint limits for compound joints (joints whose limits depend on the value of another joint).

Supported robots All robots supported by the framework. Note that for custom robots, all you need to do is define a default set of collision pairs and limits for the CompoundJointConstraint if appropriate (see the tutorial on integrating a new robot).

Running To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite interface.

MainRobot: JVRC1
Enabled: Posture

CoM

The CoM sample controller (see online demonstration) has similar tasks and constraints as the Posture controller above.

Tasks

• mc_tasks::PostureTask: A posture task with low-weight to provide a default target for all joints.
• mc_tasks::CoMTask: Task controlling the robot’s CoM. By default this controller targets the current task position. You can move this target using the interactive markers in the GUI (rviz).

Constraints

• mc_solver::ContactConstraint: Adds contacts between the left/right foot and the ground environment.
• mc_solver::DynamicsConstraint: In addition to the joint limits constraint provided by the mc_solver::KinematicsConstraint this constraint enables computation of the joint torques and friction cones.
• mc_solver::CollisionsConstraint: Self-collision avoidance constraint.
• mc_solver::CompoundJointConstraint: Handle joint limits for compound joints (joints whose limits depend on the value of another joint).

Supported robots All biped robots supported by the framework. Note that for custom robots, all you need to do is define a LeftFoot and RightFoot surface in your robot description.

Running To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite interface.

MainRobot: JVRC1
Enabled: CoM

EndEffector

The EndEffector controller (see online demonstration) has the same tasks and constraints as the CoM controller above. In addition to controlling the CoM position, it adds an mc_tasks::EndEffectorTask to control the position and orientation of the robot’s hand end-effector.

Supported robots All biped robots supported by the framework. Note that for custom robots, all you need to do is define a LeftFoot and RightFoot surfaces and an r_wrist body in your robot.

Running To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite interface.

MainRobot: JVRC1
Enabled: EndEffector

Text

The Text sample controller demonstrate the use of mc_tasks::MetaTaskLoader and mc_solver::ConstraintSetLoader to respectively load tasks and constraints from their YAML configuration.

Running To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite interface.

MainRobot: JVRC1
Enabled: Text

The default configuration for this controller is similar to the EndEffector controller. You can try writing your own configuration in ~/.config/mc_rtc/controllers/Text.yaml. For example, the following configuration re-creates the CoM controller and moves the CoM above the LeftFoot surface:

Text:
  constraints:
  - type: dynamics
  - type: contact
  - type: collision
  - type: compoundJoint
  tasks:
  - type: com
    weight: 1000
    above: [LeftFoot]
  contacts:
  - r1Surface: LeftFoot
    r2Surface: AllGround
    isFixed: false
  - r1Surface: RightFoot
    r2Surface: AllGround
    isFixed: false

Admittance

The Admittance sample controller demonstrates the use of the mc_tasks::force::AdmittanceTask though a simple FSM making the JVRC1 robot push a wall with a desired force.

Detailed description: see the Admittance Sample Controller tutorial

Supported robots: JVRC1.

Prerequisites: Please make sure that the hand force sensors have been calibrated beforehand using the ForceSensorCalibration controller.

Running

To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite dynamic simulation (e.g Choreonoid…).

See also

For a similar but more advanced example, see the ExternalForces sample.

MainRobot: JVRC1
Enabled: AdmittanceSample

Impedance

The Impedance sample controller demonstrates the use of the mc_tasks::force::ImpedanceTask to simulataneously perform position and force control of the robot’s end-effector.

Supported robots: JVRC1Fixed.

Prerequisites: Please make sure that the hand force sensors have been calibrated beforehand using the ForceSensorCalibration controller.

Running

To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite dynamic simulation (e.g Choreonoid…). In choreonoid you can apply external forces by clicking on the moving hand and dragging it. It will follow you to some extent and return to it’s expected position along the trajectory when you relase the force. Note that you may add additional mc_tasks::force::ImpedanceTask to the free end-effectors throught the GUI (Global -> Add Tasks -> ImpedanceTask).

MainRobot: JVRC1Fixed
Enabled: Impedance

LIPMStabilizer

The LIPMStabilizer sample controller demonstrates the use of the mc_tasks::StabilizerTask and its corresponding convenience FSM state mc_state::StabilizerStandingState though a simple quasi-static FSM making the robot stand and step while keeping balance.

Detailed description: see the LIPM Stabilizer tutorial

Supported robots: All biped robots supported by the framework.

Running

To run this controller, simply put in your mc_rtc configuration, and run the controller using your favorite dynamic simulation (e.g Choreonoid…).

MainRobot: JVRC1
Enabled: LIPMStabilizer

ExternalForces

The ExternalForces sample controller demonstrates a biped robot exerting specified external forces with mc_tasks::lipm_stabilizer::StabilizerTask and mc_tasks::force::ImpedanceTask though a simple FSM making the JVRC1 robot push a wall with desired forces.

Supported robots: JVRC1.

Prerequisites: Please make sure that the hand force sensors have been calibrated beforehand using the ForceSensorCalibration controller.

Running

To run the sample, you need a dynamic simulator in order to simulate the force sensors. This tutorial is intended to be used with mc_openrtm and Choreonoid, and the provided simulation file sim_mc_wall.cnoid. If you use another simulator, you will need to adapt the instructions, and create a scene with a wall 55cm away from the robot.

Put in your mc_rtc configuration, and run the controller with Choreonoid. The robot reaches both hands to the wall and applies the specified external forces of the sine wave to the wall with leaning forward.

MainRobot: JVRC1
Enabled: ExternalForces