Stack Overflow
Stack Overflow

Questions tagged [drake]

Drake is an open-source toolbox for planning, control, and analysis of nonlinear systems, developed in C++ with bindings available in Python.

Drake is an open-source toolbox for planning, control, and analysis of nonlinear systems, developed in C++ with bindings available in Python.

Resources

692 questions
3
votes
1 answer

Building and Using pydrake from source

I am simply trying to build and use pydrake from source. I have seen the Jupyter notebooks on how to use pydrake and they are helpful, but I would like to do this from source on my machine. I am unable to find instructions anywhere on how to build…
cmoses
  • 196
  • 1
  • 2
  • 16
3
votes
1 answer

With MultibodyPlant, why do I get `SolveQuadraticForTheSmallestPositiveRoot(): condition 'Delta > 0' failed`?

(This is from a Drake Slack conversation.) I'm playing with an "exploding IIWA" demo to prototype some workflows with MultibodyPlant and SceneGraph. Basically, I'm just adding a robot arm that has articulation (revolute joints between multiple…
Eric Cousineau
  • 1,944
  • 14
  • 23
3
votes
2 answers

Saving videos with meshcat?

What is the standard way of saving videos using MeshcatVisualizer? I know the following works for wrappers of PyPlotVisualizer: visualizer.start_recording() simulator.AdvanceTo(T) ani = visualizer.get_recording_as_animation() But the two relevant…
Joao Loula
  • 91
  • 4
3
votes
1 answer

Finding Contact Jacobian by mirroring internal function CalcNormalAndTangentContactJacobians()

I'm trying to find contact Jacobian defined as M(q) q_ddot + C(q, q_dot) = G(q) + B(q) u + J'(q) lambda. I tried to mirror the function CalcNormalAndTangentContactJacobians() as in multibody_plant.cclink but the values are not adding up. Here is…
zliu
  • 143
  • 6
3
votes
1 answer

What does "The following environment does not have an entry for the variable" mean in the context of a FiniteHorizonLinearQuadraticRegulator

Background I am running direct colocation and feeding the result into FiniteHorizonLinearQuadraticRegulator to stabilize the trajectory, but I havee run into an error when constructing the FHLQR. I am trying to understand what the following…
Eric Boehlke
  • 31
  • 2
3
votes
3 answers

How to implement joint limits for discrete multibodyplant simulation

I'm implementing a two-link acrobot simulation using pydrake and would like to enforce joint limits to prevent the lower link from colliding with the upper link. I've added the joint limits to the URDF and am parsing this URDF to generate an acrobot…
popcornelves
  • 31
  • 2
2
votes
1 answer

Get cost of initial guess and set cost description

I understand how to check the constraint satisfaction at initial guess, and how to set a description for constraint. This is using .evaluator().set_description( and prog.CheckSatisfiedAtInitialGuess. But how do we do these things for costs? The…
HoliInn
  • 169
  • 6
2
votes
1 answer

Improve the speed of SNOPT solver for MPC trajectory optimization

I am using pydrake SNOPT to solve a trajectory optimization problem for multi-step walking with linear inverted pendulum model. The 2-step trajectory takes 0.6s to solve. A speed-up is needed for real-time MPC. I have tried several ways to improve…
Zion
  • 21
  • 3
2
votes
1 answer

Applying force to planar joint

I'm trying to make a ball roll on a plane, so I created a planar joint between the ball and the plane. When I create a transmission to apply a force for this joint, I get the error: SystemExit: Failure at…
Ben Kang
  • 21
  • 3
2
votes
1 answer

Type error in getting context from rootContext

I am trying to include my URDF file with a robot that has contact tags activated, and I intend to use DirectCollocation to generate an optimal trajectory for my robot. First I tried creating the plant using MultibodyPlant(), then created the…
Grama Shourie
  • 47
  • 5
2
votes
1 answer

Unable to use underlay ros2 installation with drake-ros as an external in a Bazel Workspace

Using ros2_local_repository following the ros-humble installation (the debian way) yields errors the following CMAKE errors - --- captured stderr --- CMake Warning at…
adeeb10abbas
  • 37
  • 5
2
votes
0 answers

PyDrake NLOpt Method Selection

NLOpt has many different methods implemented as detailed here. I was wondering which one is used by default, and whether I could specify one of them in particular using the SolverOptions interface in pydrake. I've tried, for example, solver =…
robodobo
  • 23
  • 1
  • 3
2
votes
0 answers

Linear solve warning when simulating deformable object

We are using the deformable_torus example in examples/multibody/deformable_torus modified to use the stanford bunny tetmesh (which we created using TetWild) where the bunny falls from some small hight. The simulation runs fine until the bunny hits…
Sunny Duan
  • 21
  • 1
2
votes
1 answer

Drake - Equations of motion for a walking robot size mismatch

I'm trying to calculate the equations of motion for a walking robot to constrain its motion in a mathematical program. M(q) q_ddot + C(q, q_dot) = G(q) + B(q) u + J'(q) lambda We're basing our implementation on this pre-existing manipulator equation…
Remi Makinwa
  • 33
  • 4
2
votes
1 answer

DiagramBuilder: Cannot operate on ports of System plant until it has been registered using AddSystem

I have an issue working with DiagramBuilder and ManipulationStation classes. It appears to me, that c++ API and the python bindings work differently in my case. C++ API behaves as expected, while the python bindings result in the runtime…
Dmitri K
  • 331
  • 1
  • 12
1 2
3
…
46 47