DarwinOP (Dynamic Anthropomorphic Robot With Intelligence-Open Platform) is an open source (software/hardware) humanoid manufactured by Robotis in collaboration with Virginia Tech, Purdue University, and the University of Pennsylvania.

The DarwinOP used a total of 20x DOF, actuated with Dynamixel MX-28T servo's. Subsequent to the success of the original DarwinOP, the DarwinOP2 was released. Both versions utilise the Dynamixel MX-28T servo's, have 20x DOF, weigh 2.9kg & stand at 454.5mm tall.

DarwinOP has competed & took first place in the kids-size (400-600mm restriction) league of Robocup three consecutive years running (2011, 2012 & 2013).

The Open-Source nature & documentation of various studies on the DarwinOP platform allow for extensive research into its morphology, mechanical design and dynamic control methods. It is hoped that at least. Theres potentially many valuable insights to be gathered within this information which could be adapted & ported to a larger bipedal design.

Possibly the most familiar, and perhaps most popular humanoids in the hobby humanoid circuit is the Kondo KHR-3HV. The KHR-3HV's popularity grew exponentially after a series of YouTube videos began surfacing, posted by a mysterious 'Dr Guero' figure. One video showed the KHR-3HV walking casually across a wooden floor in the most humanlike fashion, another shows the KHR-3HV cycling around on a tailor made tiny bicycle, yet another video appeared of KHR-3HV walking across a tightrope, and many other videos of the KHR-3HV performing incredible feats have appeared since. It is for these displays of astonishing abilities of balance the KHR-3HV platform should be put under the microscope.

An Open Source (software & hardware) 3d printable, 84cm tall, 3.5kg humanoid. Possibly one of the most interesting aspects of this project (to date) & highly worth exploring is why any bipedal video material has always been 'aides' in some respect or another. It is important to also explore the many impediments to achieving bipedal locomotion in order to achieve success the success of 'unaided' bipedal locomotion.

Continuing on from the previous success of the CHARLI-L, Dennis Hong lead the development of the CHARLI-2. One of the more noteable mechanical design differences was the loss of the Four-bar linkage/stretched-spring-configuration, the adoption of simple 1:3 pinion-gear about major DOF's of the legs, the reduction of overall weight & the considerable improvements in both walking speed & gait. Again, CHARLI-2 has many experiment, test & resulting analysis documented containing a wealth of information free to study.

Discussions around motor controller boards (DIY/Off-The-Shelf) options, most suitable Communication Protocols, types of Sensors (Position, speed, current, temp). Ultimately deciding upon criteria of Actuators sensing/control specs & parameters to meet essential requirements.

Discussion of Key specifications, ratio required to achieve speed & torque, (keeping size, weight & affordability in mind). Types of gear-drives, benefits & shortcomings of each type. Overcoming cost prohibitive options. Investigating material properties wherever fabrication may be possible.