Contact Sensor Reading Problem: can not get the right data from contact sensor

Omniverse Isaac Sim
1

Hey everyone:

I’m trying to acquire the contact sensor data from Isaac sim.
First I add the sensor in isaac sim gui as the following:

1685007957767
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Then I write the code in my task.py
The followings are my code:

from omni.isaac.sensor import _sensor
...
self._cs = _sensor.acquire_contact_sensor_interface()
...
sensor_data = self._cs.get_sensor_readings("/World/final6_only_hand/__6_2/__6_2/Contact_Sensor")

and the output is:
[]
and I also tried the function: get_contact_sensor_raw_data but not work.
So how can I get the data from the contact sensor?

Thanks in advance!

3

can anyone help me?

4

Can you try following steps?

  1. Make sure that contact sensor is set up correctly in the scene. Make sure its position, orientation, and other settings.Contact Sensor — Omniverse Robotics documentation

  2. Ensure sensor path in your code matches the exact hierarchy of the contact sensor in your scene. You can do so by inspecting the scene hierarchy in Isaac Sim.

  3. Update the simulation steps if needed. Sometimes, sensor data may not be available immediately due to simulation steps being too low.

  4. Run the simulation and check the output of sensor_data. If the contact sensor is set up correctly and simulation is running then you should see the sensor readings in the sensor_data variable.

from omni.isaac.sensor import _sensor

# Acquire the contact sensor interface
contact_sensor_interface = _sensor.acquire_contact_sensor_interface()

# Define the sensor path
sensor_path = "/World/final6_only_hand/__6_2/__6_2/Contact_Sensor"

# Run the simulation (make sure to start the simulation before trying to get sensor readings)

# Get sensor readings
sensor_data = contact_sensor_interface.get_sensor_readings(sensor_path)

# Print sensor data
print("Sensor Data:", sensor_data)

Make sure to start the simulation before trying to get sensor readings. Let us know if you still see the issues.

5

Can you post a screenshot of your stage window filtered by Rigid Body, and filtered by Collision API?
I want to check if the scene setup is correct.

6

Did you solve the problem? I got the same problem when building up scene from my urdf and add cube with contact sensor but sensor doesn’t detect any contact

7

Did you add a contact reporter to cube?
When I tried to the contact sensor tutorial, I could not get contact sensor data by missing a contact reporter.
Please refer to below topic.

8

HI, I followed the contact sensor tutorials and I found my cube with sensor come with a contact reporter after I loaded the scene:
image
and I can’t add another contact reporter manually.
However, I did have the same problem:

image
image2319×17 3.32 KB

here are what I got with cs_raw_data = self._contact_sensor_interface.get_contact_sensor_raw_data(self.sensor_prim) print(str(cs_raw_data)) value = self.sensor.get_current_frame() print(value):

image
image1015×185 26.9 KB

9

I couldn’t reproduce it with only your information, so I will give a simple example.

import os
from omni.isaac.kit import SimulationApp

simulation_app = SimulationApp({"headless": False})

import omni
from omni.isaac.core import World
from omni.isaac.core.objects import DynamicCuboid
from pxr import UsdGeom, PhysxSchema
from omni.isaac.sensor import ContactSensor
import numpy as np

stage_handle = omni.usd.get_context().get_stage()

my_world = World(stage_units_in_meters=1.0)
my_world.scene.add_default_ground_plane()

cube = my_world.scene.add(DynamicCuboid(prim_path="/World/random_cube", name="fancy_cube", position=np.array([4, 2, 0.5]), scale=np.array([0.515, 0.515, 0.515]), color=np.array([4, 2, 1.0])))

contact_report_api = PhysxSchema.PhysxContactReportAPI.Apply(stage_handle.GetPrimAtPath("/World/random_cube"))
contact_report_api.CreateThresholdAttr(0.0)

sensor = ContactSensor(
            prim_path="/World/random_cube/Contact_Sensor",
            name="Contact_Sensor",
            frequency=60,
            translation=np.array([0, 0, 0]),
            min_threshold=0,
            max_threshold=10000000,
            radius=1
        )

while simulation_app.is_running():
    my_world.step(render=True)
    if my_world.is_playing():
        value = sensor.get_current_frame()
        print(value)
simulation_app.close()
11

Thanks a lot for your help, and I missed the application of PhysxContactReportAPI in my code. After applying the api, the contact force can be detected.