Hi,
I’m having an issue with the follow_target task for a robot that I imported. Basically the robot consists of a Franka Robot on top of a rotating link. I generated the urdf that results to be imported correctly in simulation and then the robot_description.yaml file. In the description file I specified the links related to the rotating stage to be fixed, and created collision meshes as well for my end_effector, which is different from the standard panda grippers in simulation. Attached you can find a copy of these files:
api_version: 1.0
Defines the generalized coordinates. Each generalized coordinate is assumed
to have an entry in the URDF, except when otherwise specified below under
cspace_urdf_bridge
cspace:
- panda_joint1
- panda_joint2
- panda_joint3
- panda_joint4
- panda_joint5
- panda_joint6
- panda_joint7
default_q: [
# Original version
# 0.00, 0.00, 0.00, -1.57, 0.00, 1.50, 0.75
# New config
0.00, 0.00, 0.00, -1.57, 0.00, 1.50, 0.75
]
acceleration_limits: [15.0, 7.5, 10.0, 12.5, 15.0, 20.0, 20.0]
jerk_limits: [7500.0, 3750.0, 5000.0, 6250.0, 7500.0, 10000.0, 10000.0]
Most dimensions of the cspace have a direct corresponding element
in the URDF. This list of rules defines how unspecified coordinates
should be extracted.
cspace_to_urdf_rules:
- {name: Joint_XX, rule: fixed, value: 0.0}
- {name: Joint_YY, rule: fixed, value: 0.0}
collision_spheres:
- panda_link0:
- “center”: [0.0, 0.0, 0.05]
“radius”: 0.045
- panda_link1:
- “center”: [0.0, -0.08, 0.0]
“radius”: 0.06
- “center”: [0.0, -0.03, 0.0]
“radius”: 0.06
- “center”: [0.0, 0.0, -0.12]
“radius”: 0.06
- “center”: [0.0, 0.0, -0.17]
“radius”: 0.06
- panda_link2:
- “center”: [0.0, 0.0, 0.03]
“radius”: 0.06
- “center”: [0.0, 0.0, 0.08]
“radius”: 0.06
- “center”: [0.0, -0.12, 0.0]
“radius”: 0.06
- “center”: [0.0, -0.17, 0.0]
“radius”: 0.06
- panda_link3:
- “center”: [0.0, 0.0, -0.06]
“radius”: 0.05
- “center”: [0.0, 0.0, -0.1]
“radius”: 0.06
- “center”: [0.08, 0.06, 0.0]
“radius”: 0.055
- “center”: [0.08, 0.02, 0.0]
“radius”: 0.055
- panda_link4:
- “center”: [0.0, 0.0, 0.02]
“radius”: 0.055
- “center”: [0.0, 0.0, 0.06]
“radius”: 0.055
- “center”: [-0.08, 0.095, 0.0]
“radius”: 0.06
- “center”: [-0.08, 0.06, 0.0]
“radius”: 0.055
- panda_link5:
- “center”: [0.0, 0.055, 0.0]
“radius”: 0.06
- “center”: [0.0, 0.075, 0.0]
“radius”: 0.06
- “center”: [0.0, 0.000, -0.22]
“radius”: 0.06
- “center”: [0.0, 0.05, -0.18]
“radius”: 0.05
- “center”: [0.01, 0.08, -0.14]
“radius”: 0.025
- “center”: [0.01, 0.085, -0.11]
“radius”: 0.025
- “center”: [0.01, 0.09, -0.08]
“radius”: 0.025
- “center”: [0.01, 0.095, -0.05]
“radius”: 0.025
- “center”: [-0.01, 0.08, -0.14]
“radius”: 0.025
- “center”: [-0.01, 0.085, -0.11]
“radius”: 0.025
- “center”: [-0.01, 0.09, -0.08]
“radius”: 0.025
- “center”: [-0.01, 0.095, -0.05]
“radius”: 0.025
- panda_link6:
- “center”: [0.0, 0.0, 0.0]
“radius”: 0.06
- “center”: [0.08, 0.03, 0.0]
“radius”: 0.06
- “center”: [0.08, -0.01, 0.0]
“radius”: 0.06
- end_effector:
- “center”: [-0.003, -0.004, 0.101]
“radius”: 0.05
- “center”: [0.012, -0.034, 0.263]
“radius”: 0.031
- “center”: [-0.001, -0.006, 0.126]
“radius”: 0.031
- “center”: [-0.025, 0.001, 0.009]
“radius”: 0.03
- “center”: [-0.002, -0.041, 0.145]
“radius”: 0.029
- “center”: [-0.002, -0.036, 0.216]
“radius”: 0.026
- “center”: [0.008, 0.001, 0.096]
“radius”: 0.029
- “center”: [-0.023, -0.019, 0.102]
“radius”: 0.028
- “center”: [0.003, 0.012, 0.098]
“radius”: 0.026
- “center”: [0.014, -0.012, 0.084]
“radius”: 0.028
- “center”: [-0.003, -0.037, 0.188]
“radius”: 0.027
- “center”: [0.007, -0.034, 0.296]
“radius”: 0.021
- “center”: [0.0, -0.021, 0.125]
“radius”: 0.038
rotating_panda.txt (9.7 KB)
Now, in order to accomplish the target following, I modified the FollowTarget(tasks.FollowTarget) class returning Articulation(prim_path = self._franka_prim_path, name = self._franka_robot_name) instead of Franka(…), adding to the stage the usd of the robot, in the position self._franka_prim_path.
Then, I modified the rpmflow_controller, replacing “self.rmp_flow_config = mg.interface_config_loader.load_supported_motion_policy_config(“Franka”, “RMPflow”) / self._rmp_flow = mg.lula.motion_policies.RmpFlow(**self.rmp_flow_config)” with
mg_extension_path = get_extension_path_from_name(“omni.isaac.motion_generation”)
kinematics_config_dir = os.path.join(mg_extension_path, “motion_policy_configs”)
rotating_franka_description_path = kinematics_config_dir + “/franka/rmpflow/rotating_franka.yaml”,
urdf_rotating_franka_path = kinematics_config_dir + “/franka/rotating_panda.urdf”
rotating_franka_end_effector_name = “end_effector”
self.rmp_flow = mg.lula.motion_policies.RmpFlow(self, robot_description_path = rotating_franka_description_path, urdf_path = urdf_rotating_franka_path, end_effector_frame_name = rotating_franka_end_effector_name )
Still got no luck, resulting in the following error: await self.setup_post_load()
File “/home/robot/.local/share/ov/pkg/isaac_sim-2022.2.1/exts/omni.isaac.examples/omni/isaac/examples/follow_target/follow_target.py”, line 53, in setup_post_load
self._controller = RMPFlowController(name=“target_follower_controller”, robot_articulation=my_franka)
File “/home/robot/.local/share/ov/pkg/isaac_sim-2022.2.1/exts/omni.isaac.franka/omni/isaac/franka/controllers/rmpflow_controller.py”, line 30, in init
self.rmp_flow = mg.lula.motion_policies.RmpFlow(self, robot_description_path = rotating_franka_description_path, urdf_path = urdf_rotating_franka_path, end_effector_frame_name = rotating_franka_end_effector_name )
TypeError: init() got multiple values for argument ‘robot_description_path’
Robot and target load correctly on the screen, and the robot moves when the target moves, but incorrectly. Is there anything I missed in the integration of my robot in the follow target task?