Contact Sensor Extension [omni.isaac.contact_sensor]

The Contact Sensor Extension provides a set of utilities to read Contact data, and set up simulated load sensors.

Basic Usage

Setting Up a Sensor

First, aquire the sensor interface:

from omni.isaac.contact_sensor import _contact_sensor
_cs = _contact_sensor.acquire_contact_sensor_interface()

Then, Create a SensorProperties object, and set the values according to the sensor specifications:

props = _contact_sensor.SensorProperties()
props.radius = 12 # cover the body tip
props.minThreshold = 0
props.maxThreshold = 1000000000000
props.sensorPeriod = 1 / 100.0
props.position = carb.Float3(40, 0, 0) # Offset sensor 40cm in X direction from rigid body center

Finally, add it to the desired rigid body using its prim path:

sensor_handle = _cs.add_sensor_on_body("/path/to/rigid_body", props)

To collect the readings, call the interface get_sensor_sim_reading. the result will be the accumulated readings since last time the sensor was read. Each reading is timestamped, and contains a boolean flag to tell if the sensor is triggered.

readings = _cs.get_sensor_readings(sensor_handle)

Acquiring Extension Interface

_contact_sensor.acquire_contact_sensor_interface(plugin_name: str = None, library_path: str = None) → omni::isaac::contact_sensor::ContactSensorInterface

Acquire Contact Sensor interface. This is the base object that all of the Contact Sensor functions are defined on

_contact_sensor.release_contact_sensor_interface(arg0: omni::isaac::contact_sensor::ContactSensorInterface) → None

Release Contact Sensor interface. Generally this does not need to be called, the Contact Sensor interface is released on extension shutdown

Contact Sensor API

Input Types

class SensorProperties

Sensor Properties

property maxThreshold

Maximum force that the sensor can register. Forces above this value will be clamped. (float)

property minThreshold

Minimum force that the sensor can read. Forces below this value will not trigger a reading. (float)

property position

Position relative to the parent body where the sensor is placed. (carb.Float3)

property radius

Sensor radius. Negative values indicate it’s a full body sensor. (float)

property sensorPeriod

Sensor reading period in seconds. zero means sync with simulation timestep (float)

Output Types

class SensorReading

Sensor Reading

property inContact

boolean that flags if the sensor registers a contact. (bool)

property time

timestamp of the reading, in seconds . (float)

property value

sensor force reading value. (float)

class CsRawData

Contact Raw Data

property body0

Body 0 name handle, (int)

property body1

Body 1 name handle, (int)

property dt

timestep during this contact report, (float)

property impulse

impulse, global coordinates , (carb.Float3)

property normal

normal, global coordinates , (carb.Float3)

property position

position, global coordinates, (carb.Float3)

property time

simulation timestamp, (float)

Interface Methods

class ContactSensorInterface

add_sensor_on_body(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: str, arg1: omni.isaac.contact_sensor._contact_sensor.SensorProperties) → int

Parameters

arg0 (SensorProperties) – the sensor properties

Returns

The sensor handle

Return type

int

decode_body_name(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: int) → str

Decodes the body name pointers from the contact raw data into a string :param arg0: body name handle :type arg0: int

Returns

The body name.

Return type

str

get_body_contact_raw_data(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: str) → object

Parameters

arg0 (str) – USD Path to body as string

Returns

The list of contact raw data that contains the specified body.

Return type

numpy.array

get_num_sensors_on_body(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: str) → int

Gets the number of sensors that were attached to the given body. :param arg0: USD Path to body as string :type arg0: str

Returns

The number of sensors attached to body.

Return type

int

get_sensor_readings(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: int) → object

Gets the list of sensor readings for the given sensor. Clears the reading buffer once values are acquired. :param arg0: the sensor handle :type arg0: int

Returns

The list of readings for the sensor ready on the buffer.

Return type

numpy.array

get_sensor_readings_size(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: int) → int

Gets the number of readings ready on the buffer :param arg0: the sensor handle :type arg0: int

Returns

Number of readings ready on the buffer.

Return type

int

get_sensor_sim_reading(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: int) → omni.isaac.contact_sensor._contact_sensor.SensorReading

Parameters

arg0 (int) – the sensor handle

Returns

The reading for the current simulation time.

Return type

numpy.array

get_sensors_on_body(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: str) → object

Gets the list of sensor handles attached to a given body. :param arg0: USD Path to body as string :type arg0: str

Returns

The list of sensor handles on a body.

Return type

numpy.array

remove_sensor(self: omni.isaac.contact_sensor._contact_sensor.ContactSensorInterface, arg0: int) → bool

Parameters

arg0 (int) – the sensor handle

Returns

True if succesful, False otherwise.

Return type

boolean