Designed from the ground up.
Throughout the three years of research and testing, we've developed PROTO1 to be a cost-efficient humanoid robot. PROTO1 is completely constructed from 3D printed pieces, allowing us to rapidly prototype and implement our designs. By coupling this with the use of readily available hardware and electronics, we're able to keep costs low while maintaining exceptional strength and control.
The hand is controlled with a total of 6 servo motors: one micro servo for the opposable thumb and 5 standard servos controlling the fingers and wrist located in the upper forearm. Each servo motor is connected to its corresponding finger through a thin cable which runs through the hand acting as a tendon to pull the fingers closed. Through precise control of the servos, the hand is able to vary how far and with what pressure the fingers close, this allows it to perfectly contour around most objects and hold them firmly. On the back of the hand there’s flexible nylon paracord running up one side of the fingers and looped back where it’s tied off. This perpetually holds the fingers in the open position until the servos pull the wire connected to the fingers to close the hand.
The elbow is controlled using a large high-torque servo motor in the lower bicep. Because the elbow rotates roughly 110°, we geared down the elbow from the 180° turn of the servo giving it a ~1:1.6 gear ratio and ~100kg.cm of torque through a small timing belt. By having this, the elbow is able to move freely forward and backward while handling both positive and negative loads of around 5lbs. The elbow has had multiple iterations struggling to maintain both strength and weight restrictions, but after many failures and shortcomings, our current design employs a strong, fast, and robust system.
The shoulder design is built on two large geared motors acting as a gimbal for the arm to pivot on and one large high torque servo in the bicep controlling the medial/lateral shoulder motion. The abduction/adduction and flexion/extension movements are controlled with two servos which are connected to the torso and maintain all the degrees of freedom that a human arm has. All shoulder control surfaces also have the ability to handle both positive and negative loads similar to the elbow.
The torso of PROTO1 consists of an assembled chest and articulating head. 14 separately printed panels make up the chest and 6 pieces fit together to form the head which pivots on two small servo motors. In the head, there is space for a wide range of sensors and microcontrollers depending on the application. From components ranging from infrared detectors to object recognition sensors, PROTO1 is suited to interpret many different situations.