Malte Ahlers, a student of neurobiology in Germany, has built a humanoid robot torso called Adam (Advanced Dual Arm Manipulator), or A1 for short. Although the project is still somewhat early in development, the hardware side of things has been in the works for around two years already.
Unlike many personal projects that opt for hobby servos from Robotis (or another company), Adam’s arms have five degrees of freedom actuated by robolink joints from Igus, a German robotics company.
The robolink joints have both pivot and rotation – ideal for building robot arms – but they use external cables for their rotation (much like a pulley: one for clockwise and another for counter-clockwise rotation). The resulting bundle of cables had to be routed to planetary gear motors inside the torso, and he had to build a motor controller to read out the position encoders in the joints in order to drive the motors with position control. As a proof of concept, he has posted a video showing one of the shoulders moving. He’ll have to pack many more motors into Adam’s torso to get the other arm moving.
It strikes me as an awful lot of work when compared with standard hobby robot servos! Especially now that companies are offering powerful servos with the kind of torque required to move such large arms. In contrast, an extra degree of freedom in the wrists (and two in the neck) are actuated by more straightforward stepper motors.
For the hands, he went with FESTO’s flexible FinGrippers which use a simple yet surprisingly effective design. FESTO is a German company famous for its biologically-inspired robots, and the FinGrippers are no exception. Using just one motor, three fingers pinch together in unison and will naturally conform to roundish objects of varying size. Finally, Adam’s head (sitting on a 2 DOF neck) has a Microsoft Kinect sensor and two Logitech QuickCam Pro 9000 cameras. A speaker provides for speech synthesis, and an LCD panel features animated “lips”.
For now Adam remains an impressive work-in-progress, but we hope to see more from Malte in the future.
Video (speech demonstration):
Video (human tracking):