  This paper describes the hardware, software framework, and experimental
testing of SURENA IV humanoid robotics platform. SURENA IV has 43 degrees of
freedom (DoFs), including seven DoFs for each arm, six DoFs for each hand, and
six DoFs for each leg, with a height of 170 cm and a mass of 68 kg and
morphological and mass properties similar to an average adult human. SURENA IV
aims to realize a cost-effective and anthropomorphic humanoid robot for
real-world scenarios. In this way, we demonstrate a locomotion framework based
on a novel and inexpensive predictive foot sensor that enables walking with 7cm
foot position error because of accumulative error of links and connections'
deflection(that has been manufactured by the tools which are available in the
Universities). Thanks to this sensor, the robot can walk on unknown obstacles
without any force feedback, by online adaptation of foot height and
orientation. Moreover, the arm and hand of the robot have been designed to
grasp the objects with different stiffness and geometries that enable the robot
to do drilling, visual servoing of a moving object, and writing his name on the
white-board.
