ManoPla is a striking new mechatronic hand for gestural communication between a humanoid robot and the humans with whom it interacts.
ManoPla has been conceived and developed by the team of Miguel Hernando, Carlos Morillo, Alberto Brunete and Diego Guffanti. The first three are from the Center for Automaticity and Robotics (CAR), a joint research center of the Polytechnic University of Madrid (UPM) and the Superior Council for Scientific Research (CSIC), in Spain. Guffanti is from the UTE University of Santo Domingo de los Tsáchilas in Ecuador.
ManoPla’s design is natural, self-contained and low-weight, and to this end, imaginative and original solutions have been adopted in its development. ManoPla will allow guide or assistance robots to transmit, in a more natural way, emphasis, feelings and emotions, thus enriching human-robot communication.
In social robotics, a friendly and natural interaction with the human being is particularly sought. In a conversation with another person, gestural communication can be just as rich and even more emphatic than verbal communication. For this reason, in the last decade, there are many developments and investigations that focus on this interactive capacity of the robot. For example, at the UPM’s Higher Technical School of Engineering and Industrial Design (ETSIDI) they have developed a humanoid social robot Hidalgo and, for him, it was decided to design a robotic hand that was as similar to the human hand in terms of mobility.
The result of this line of research is ManoPla, whose current functional prototype has 17 controllable joints plus 4 passive ones. The four joints of the fingers are actuated by means of three motors (following the model proposed by the humanoid astronaut Robonaut). The thumb, due to its uniqueness, controls the four joints with which it has been modeled. In addition, the palm can warp, managing to emulate in an exceptional way the human morphology and its movements naturally. Given that ManoPla is completely self-contained (both for the actuation systems and for the control, and that it has its own microcontroller to regulate all the movements and measure and serve the information), the most relevant physical problem that has arisen is the limitation of the space.
3D visualization of ManoPla. (Image: Carlos Morillo)
The use of mechatronic design methods that share the three fields covered: mechanics, electronics and programming, has made it possible to develop the final fully functional prototype. In this design everything is used. This means, for example, that the electronic board is structural, and even has all the possible sensors integrated, adapting the mechanics of the fingers and the sensors to make this possible. In addition, specific solutions have been developed to achieve elastic actuations with optical joint transducers of novel and specific configuration and design.
All these solutions make the hand a meticulous engineering project with its own identity, which has constantly sought alternative solutions to problems that are difficult to solve. The software design has been studied in detail to achieve absolute control in the robotic hand. Thanks to the low-level programming of the microcontroller, it has been possible to optimize the execution cycles and the processing frequencies of each of the elements have been controlled. Finally, it should be noted that the external appearance of the hand is not merely decorative either. Each of the pieces of both the fingers and the palm is part of some internal mechanism, so the final appearance is totally linked by functionality. In total, ManoPla weighs only 250 grams, integrates 17 motors and 17 sensors, and has 22 joints, with their respective power electronics and control system. The only thing that it does not integrate is a battery since it is considered that it will always have to be supported by a robotic arm through which the necessary energy for its operation reaches it.
The impact, mobility and grip tests carried out have aroused interest in the field of social robotics, so that part of their development has been published in the International Journal of Social Robotics, a particularly prestigious journal in this field of robotics. robotics.
The researchers involved in the development of ManoPla expose the technical details of this in the academic journal International Journal of Social Robotics, under the title “Mechatronic Design of a Self-Contained Dexterous Robotic Hand for Gestural Communication”. (Source: UPM)