© All rights reserved - Iman Hemmatian Last Update : March. 25, 2011 Sharif University of Technology Home Publications Invention Awards & memberships Research interest Accomplishement Work exp. & cv Gallery Contact Home Publications Invention Awards & memberships Research interest Accomplishments Work exp. & cv Gallery Contact Sharif University of Technology Nonlinear Power Transmission Joint with Adjustment Capability  (Patent No. 64414; Iranian Patent Office, Iran)  Isometric View By the necessity of more accurate and efficient robotic systems in technology, the drive  systems for robot manipulators became important. The problems associated with  traditional transmission methods like gearboxes, such as friction, backlash and  compliance, and the development of electric motors for robotic applications, led to a new  design approach called direct-drive (DD) transmission. In this method the shaft of the  motor is directly coupled to the joint of the manipulator. The problem associated to this  kind of transmission is that the weight of the motors attached to robot joints reduces the  payload. So existence of an intermediate element that provides relocation becomes  important, leading to a design, named direct transmission (DT). This transmission method  has higher performance than DD, however, because dynamic complexities – like coupling  and non-linearity – are directly reflected on the motor shaft, one cannot use common  single-input single-output (SISO) control techniques to control the robot. This problem  can be resolved using more advanced control methods like model-based or computed  torque control. Another way is to redesign the manipulator to reduce dynamic complexity.  We proposed non-linear drive transmission which has the advantages of DT and  reduction ratio properties of gearboxes. It has very little friction, backlash, and  compliance compared to the traditional methods, while providing actuator relocation,  directness of DD, and a varying reduction ratio. The Nonlinear Power Transmission Joint  with Adjustment Capability, shown in Fig. It has all the advantages mentioned for DT  mechanisms. Isometric View