Hardware components

The PR2 hardware interface provides a C++ abstraction layer for the PR2 hardware that is controlled over the etherCAT link that runs through the robot. Most users should not have to deal directly with this interface. If you are only interested in controlling the robot joints, you should directly interact with pr2_mechanism_model. Only very advanced users that need direct access to the hardware should be using the PR2 hardware interface.

• Hardware Interface: The HardwareInterface class provides access to the PR2 hardware components that are controlled via EtherCAT. These components include:

  • Actuators: the PR2 robot contains 32 actuators, and each actuator consists of a motor and an encoder.

  • Pressure sensors: the fingertips of the PR2 have pressure sensors that provide an array of force measurements.

  • Accelerometers: the PR2 grippers contain 3 axis accelerometers. Instruction on communicating with these sensors in real-time can be found here.

  • Digital out: The PR2's motor controller boards have one or more digital I/O pins. The digital I/Os can be used to control a variety of hardware such as a calibration LED or a camera trigger.

  • Projector: the PR2 head has a texture projector mounted on its head. The texture helps the stereo cameras to see objects that naturally have no texture.

  • AnalogIn: Some EtherCAT devices such as Beckhoff EL3064 represent inputs as array of analog values.