8 IR-based Time of Flight sensors (used for obstacle avoidance) - three on the front, one on back, and 4 edge/downward
10 bump sensors (used to stop in case of a sudden obstacle) - three tied in parallel on the front corners and two tied in parallel on each rear corner
4 cliff sensors (used to avoid falling down stairs or off tables) - two on the front and two on the back
6 capacitive touch sensors (to detect human interaction) - in the head and chin
Occipital Structure Core depth sensor (2 IR cameras, 1 fisheye camera, 1 IMU)
4K camera (to handle remote video streaming, picture capture and object/face/people detection and recognition)
2 IMU sensors (3-axis gyroscope, 3-axis accelerometer) - one in the Occipital sensor and 1 on the robot itself and a 3x far-field microphone array.