REAL Environment

The REAL environment is a standard gym environment.
It includes a 7DoF kuka arm with a 2Dof gripper, a table with 3 objects on it and a camera looking at the table from the top.
The gripper has four touch sensors on the inner part of its links.

Action

The actionattribute of env.step must be a vector of 9 joint positions in radiants. The first 7 joints have a range between -Pi/2 and +Pi/2. The two gripper joints have a range between 0 and +Pi/2. They are also coupled so that the second joint will be at most twice the angle of the first one.

index joint name 0 lbr_iiwa_joint_1 1 lbr_iiwa_joint_2 2 lbr_iiwa_joint_3 3 lbr_iiwa_joint_4 4 lbr_iiwa_joint_5 5 lbr_iiwa_joint_6 6 lbr_iiwa_joint_7 7 base_to_finger0_joint 8 finger0_to_finger1_joint

Observation

The observation object returned byenv.step is a dictionary:

• observation["joint_positions"] is a vector containing the current angles of the 9 joints
• observation["touch_sensors"] is a vector containing the current touch intensity at the four touch sensors (see figure below)
• observation["retina"] is a 240x320x3 array with the current top camera image
• observation["goal"] is a 240x320x3 array with the target top camera image (all zeros except for the extrinsic phase, see below)

Additional observations are available if the "Easy" environment is activated:

• observation["object_positions"] is a dictionary with object names as keys and the x, y, z position of the objects as values.
• observation["mask"] is a 240x320x3 array corresponding to the segmented image of the retina (each pixel has a value corresponding to an object id)
• observation["goal_object_positions"] same as object positions, but referred to the goal image.
• observation["goal_mask"] same as the mask, but referred to the goal image.

For each sensor, intensity is defined as the maximum force that was exerted on it at the current timestep.

Reward

The reward value returned byenv.step is always put to 0.

Done

The done value returned byenv.step is set to True only when the intrinsic phase or an extrinsic trial is concluded.