Development of high performance servo drive/anti drive mechanism for backlash removal
Keywords: 1 Degree of freedom Platform, Backlash Removal, System Modelling. Abstract: In electromechanical drives, there is always a backlash between any pair of gears. Because of this, it is almost impossible to realize a high accuracy and high performance drive. However such drives are crucial in today’s modern electromechanical systems. A high performance drive/anti-drive servo mechanism is developed to eliminate the effect of backlash. The concept utilizes redundant unidirectional drives to assure positive coupling of gear meshes at all times. Based on this concept, a methodology for enumeration of admissible redundant-drive backlash free mechanism has been established. The angular displacement is achieved as a difference of two torques. These torques can be controlled by a high performance control system. A controller model will be designed to move a single degree of freedom platform up to a desired span with a payload.
Development of a 2 degrees of freedom tracking system: design and fabrication of platform
This paper reports the design and fabrication of an innovative 2-DOF robotic platform for precision pointing and image-based tracking applications. Conventionally, such platforms have very simple structures but have various associated limitations. One such problem is the generally imbalanced structure due to the placement of the elevation actuator on moving base. This design causes a lot of problems when platform is operated at high angular velocities. This paper, however, proposes a new design that is balanced in structure and very light due to placement of both actuators in the stationary base, hence finding its applications in high speed tracking problems. This thing in return has caused coupling between the two degrees of freedom. However, it is a kinematics problem and can be resolved easily in the control algorithm.
Multilayer high density flex technology
The industrial trend of shrinking microelectronic devices while increasing the density of interconnections places great demands on the substrates upon which these devices are packaged. Multilayer flex circuits will provide the interconnection densities needed to meet these demands in a wide range of packaging and interconnection technologies. This paper discusses the development of ultra-high density flexible circuits. Processes and materials to fabricate fine line pitches from 12.5 /spl mu/m to 40 /spl mu/m are examined. Various microvia structures, through hole and blind via, are demonstrated. A test vehicle was designed and built for BGA packages to illustrate the density capability. A four-layer structure is demonstrated by using Z-connection to connect two layer pairs. Electrical, mechanical, and reliability test results are presented to show the selection of flex substrate material, Z-connection methodology and fabrication processes. A cost comparison of high-density flex to alternative substrates is discussed to identify potential.