目录

1. 导入模型

1.1 从过去保存的stage导入

1.2 使用代码导入单个Franka机器人

1.3 使用代码导入多个Franka机器人

​编辑

2. 控制单个Franka机械臂

2.1 位置控制

2.2 单自由度位置控制

2.2 速度控制

2.3 单自由度速度控制

2.4 力矩控制

3. 信息获取

3.1 获取单个Franka状态

3.2 获取物体状态

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API链接：

Dynamic Control [omni.isaac.dynamic_control] — isaac_sim 2022.2.1-beta.29 documentation

使用示例：

Dynamic Control — Omniverse Robotics documentation

1. 导入模型

1.1 从过去保存的stage导入

这一节中，各操作使用Sim内置的Python Script运行调试。

从文件系统可以看到，已经有一个stage1.usd保存在EnvFrank里，直接拖到界面中。

在Dynamic Control — Omniverse Robotics documentation给出了基本的读取，控制关节操作。但是，其对应的操作是默认Franka机器人在World下。控制stage1中的Franka机器人，需要修改引用为：

articulation = dc.get_articulation("/World/stage1/Franka")

注意运行前需要启动环境仿真。

测试代码为：

from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 print(dc)
 articulation = dc.get_articulation("/World/stage1/Franka")dc.wake_up_articulation(articulation)
 joint_angles = [np.random.rand(9) * 2 - 1]
 dc.set_articulation_dof_position_targets(articulation, joint_angles)
 

 该代码给Franka的9个自由度进行了随机的一次运动。

1.2 使用代码导入单个Franka机器人

首先清除界面，File->New 或者 New From Stage Template。（或者重启Sim，不然可能会加载不出ground plane）

参考示例 standalone_examplesapiomni.isaac.coreadd_frankas.py

from omni.isaac.core import World
 from omni.isaac.core.robots import Robot
 from omni.isaac.core.utils.stage import add_reference_to_stage
 from omni.isaac.core.utils.nucleus import get_assets_root_pathmy_world = World(stage_units_in_meters=1.0)
 my_world.scene.add_default_ground_plane()assets_root_path = get_assets_root_path()
 asset_path = assets_root_path + "/Isaac/Robots/Franka/franka_alt_fingers.usd"
 add_reference_to_stage(usd_path=asset_path, prim_path="/World/Franka_1")articulated_system_1 = my_world.scene.add(Robot(prim_path="/World/Franka_1", name="my_franka_1"))

 运行结果：

1.3 使用代码导入多个Franka机器人

参考示例：standalone_examplesapiomni.isaac.clonerclone_ants.py 

注意，如果在Sim内运行示例代码时ants掉落，可能default ground plane没有加载，建议重启Sim。

将Ant替换为Franka后的代码：

import numpy as np
 import omni
 from omni.isaac.core import World
 from omni.isaac.core.articulations import ArticulationView
 from omni.isaac.core.utils.stage import add_reference_to_stage, get_stage_units
 from omni.isaac.core.utils.nucleus import get_assets_root_path
 from omni.isaac.cloner import GridClonermy_world = World(stage_units_in_meters=1.0)
 my_world.scene.add_ground_plane()assets_root_path = get_assets_root_path()
 # create initial robot
 asset_path = assets_root_path + "/Isaac/Robots/Franka/franka_alt_fingers.usd"
 add_reference_to_stage(usd_path=asset_path, prim_path="/World/Franka/Franka_0")# create GridCloner instance
 cloner = GridCloner(spacing=2)# generate paths for clones
 target_paths = cloner.generate_paths("/World/Franka/Franka",8)# clone
 position_offsets = np.array([[0, 0, 0]] * 8)
 cloner.clone(source_prim_path="/World/Franka/Franka_0",prim_paths=target_paths,position_offsets=position_offsets,replicate_physics=True,base_env_path="/World/Franka",
 )# create ArticulationView
 ants = ArticulationView(prim_paths_expr="/World/Franka/.*/torso", name="Franka_view")
 my_world.scene.add(ants)my_world.reset()
 for i in range(1000):print(ants.get_world_poses())my_world.step()

运行结果：

其中prim_paths_expr="/World/Franka/.*/torso"的错误暂时没管，不清楚影响。

2. 控制单个Franka机械臂

Dynamic Control — Omniverse Robotics documentation

2.1 位置控制

导入和控制指令在Sim中运行时，Script中的指令会被Franka的初始化覆盖，所以在这里使用另一种调试。

（1）将Python Script模式修改 Option->Clear after excute，代码在运行后会自动清除。

（2）输入并运行代码，导入Franka机器人。

from omni.isaac.core import World
 from omni.isaac.core.robots import Robot
 from omni.isaac.core.utils.stage import add_reference_to_stage
 from omni.isaac.core.utils.nucleus import get_assets_root_pathmy_world = World(stage_units_in_meters=1.0)
 my_world.scene.add_default_ground_plane()assets_root_path = get_assets_root_path()
 asset_path = assets_root_path + "/Isaac/Robots/Franka/franka_alt_fingers.usd"
 add_reference_to_stage(usd_path=asset_path, prim_path="/World/Franka_1")articulated_system_1 = my_world.scene.add(Robot(prim_path="/World/Franka_1", name="my_franka_1"))

（3） 启动仿真

（4）输入并运行控制代码

from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 articulation = dc.get_articulation("/World/Franka_1")dc.wake_up_articulation(articulation)
 joint_angles = [np.random.rand(9) * 2 - 1]
 dc.set_articulation_dof_position_targets(articulation, joint_angles)

 运行结果：

2.2 单自由度位置控制

接下来的控制调试都可以在（2）导入Franka机器人 的基础上继续。

from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 articulation = dc.get_articulation("/World/Franka_1")
 dc.wake_up_articulation(articulation)
 dof_ptr = dc.find_articulation_dof(articulation, "panda_joint2")
 dc.set_dof_position_target(dof_ptr, -1.5)

2.2 速度控制

from pxr import UsdPhysics
 stage = omni.usd.get_context().get_stage()
 for prim in stage.TraverseAll():prim_type = prim.GetTypeName()if prim_type in ["PhysicsRevoluteJoint" , "PhysicsPrismaticJoint"]:if prim_type == "PhysicsRevoluteJoint":drive = UsdPhysics.DriveAPI.Get(prim, "angular")else:drive = UsdPhysics.DriveAPI.Get(prim, "linear")drive.GetStiffnessAttr().Set(0)
 from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 #Note: getting the articulation has to happen after changing the drive stiffness
 articulation = dc.get_articulation("/World/Franka_1")
 dc.wake_up_articulation(articulation)
 joint_vels = [-np.random.rand(9)*10]
 dc.set_articulation_dof_velocity_targets(articulation, joint_vels)

2.3 单自由度速度控制

from pxr import UsdPhysics
 stage = omni.usd.get_context().get_stage()
 panda_joint2_drive = UsdPhysics.DriveAPI.Get(stage.GetPrimAtPath("/Franka/panda_link1/panda_joint2"), "angular")
 panda_joint2_drive.GetStiffnessAttr().Set(0)
 from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 #Note: getting the articulation has to happen after changing the drive stiffness
 articulation = dc.get_articulation("/World/Franka_1")
 dc.wake_up_articulation(articulation)
 dof_ptr = dc.find_articulation_dof(articulation, "panda_joint2")
 dc.set_dof_velocity_target(dof_ptr, 0.2)

2.4 力矩控制

from omni.isaac.dynamic_control import _dynamic_control
 import numpy as np
 dc = _dynamic_control.acquire_dynamic_control_interface()
 articulation = dc.get_articulation("/World/Franka_1")
 dc.wake_up_articulation(articulation)
 joint_efforts = [-np.random.rand(9) * 1000]
 dc.set_articulation_dof_efforts(articulation, joint_efforts)

3. 信息获取

3.1 获取单个Franka状态

from omni.isaac.dynamic_control import _dynamic_control
 dc = _dynamic_control.acquire_dynamic_control_interface()art = dc.get_articulation("/World/Franka_1")# Get information about the structure of the articulation
 num_joints = dc.get_articulation_joint_count(art)
 num_dofs = dc.get_articulation_dof_count(art)
 num_bodies = dc.get_articulation_body_count(art)
 print(num_joints)
 print(num_dofs)
 print(num_bodies)# Print the state of each degree of freedom in the articulation
 dof_states = dc.get_articulation_dof_states(art, _dynamic_control.STATE_ALL)
 print(dof_states)# print position for the degree of freedom
 print(dof_state.pos)# Get state for a specific degree of freedom
 dof_ptr = dc.find_articulation_dof(art, "panda_joint2")
 dof_state = dc.get_dof_state(dof_ptr, _dynamic_control.STATE_ALL)
 print(dof_state)
 print(dof_ptr)

其中，可以在Stage中查看到panda_joint2的具体位置。

3.2 获取物体状态

在这里，可以直接创建一个Cube对象，放置在World中。

我直接调用了自己的环境。

Core [omni.isaac.core] — isaac_sim 2022.2.1-beta.29 documentation

from omni.isaac.core import World
 world = World()world = World(stage_units_in_meters=1.0)
 world.scene.add_default_ground_plane()from omni.isaac.core.objects import DynamicCuboid
 import numpy as npCube = world.scene.add(DynamicCuboid(prim_path = "/World/Cube",name = "my_cube",position = np.array([0,0,1]),scale = np.array([1,1,1]),color = np.array([1,1,1])))world.reset()position, oritentation = Cube.get_world_pose()
 linear_velocity = Cube.get_linear_velocity()
 angular_velocity = Cube.get_angular_velocity()print("Position is:", position)
 print("Orientation is:", oritentation)
 print("Linear velocity is:", linear_velocity)
 print("Angular velocity is:", angular_velocity)