<p> This thesis builds on a recently developed Failure Recovery Synthesis (FRS) technique for robotic manipulators, which is mounted on a movable platform to achieve an originally specified task after an arm joint failure. The FRS locks in place the failed arm joint and determines a new position for the base of the arm and a new grasping location for the end-effector. </p><p> This work aims towards improving the trajectory planning technique of the FRS in order to generate optimal reaching motions in case of an arm joint failure. Aiming towards improving the robotic trajectory planning technique in the FRS, the work adopts previous results from experimental observations on human elbow constrained reaching movements. The assumption that the end-effector of an elbow locked anthropomorphic robotic manipulator is in contact with a specific surface during the entire movement allows us to describe the contact conditions by using higher order kinematic constraints such as velocities, accelerations, and jerks. By adopting contact specifications at initial and final task locations, kinematic synthesis and path planning techniques enable us to generate an entire end-effector trajectory connecting the two locations. </p><p> The proposed method was validated by comparing its outcome to an actual human elbow-constrained reaching motion profile. The results show a smooth trajectory that closely follows the human hand path.</p><p>

<p> Compliance in legged robotics has recently become favored over rigid leg members. The energy cost associated with rigid legged walking is high, and speeds are typically decreased with terrain changes. The use of compliant legs can provide stable walking while enabling higher maximum speeds. </p><p> Inspired by biological principals in insectoid locomotion, a physical model for energy efficient limb design was explored. A compliant leg structure was designed and replaced the rigid leg members of an insectoid robot. Velocity and ground reaction force data was gathered for both rigid and compliant lower leg members at various stiffness values for ideal and complex terrain. </p><p> Furthermore, a command was designed to maximize walking speeds. Design parameters of stiffness, command duration, and command spacing are selected. The designed command, combining the optimal value of the design parameters, produced an increased stance departure velocity value and can be implemented in insectoid robots with compliant legs.</p>

<p> Path planning is a common research topic and has applications in various fields and industries, such as AI, industrial automation, and mobile robotics. When applied to mobile systems, path planning algorithms are required to plan safe and feasible paths for a system from an initial state to a desired final state. While most path planning algorithms have been designed for rigid systems, little work has focused on path planning algorithms for flexible systems. Motion planning for flexible systems has typically involved sequential methods that plan trajectories for a system, then apply vibration control techniques for trajectory tracking. This thesis proposes new algorithms that concurrently plan a path for a flexible system while limiting the induced vibration. </p><p>

No description available.

No description available.

No description available.

<p>Developing a smart home environment for the assistive living requires great efforts. The key element of the smart environment is the ubiquitous voice user interface with several additional capabilities such as the recognition of several gestures, which can be a new feature of voice controlled devices. There are many identification technologies used in current intelligent guard systems. Relative to other techniques, the voice recognition technology is generally regarded as one of the convenient and safe recognition techniques. The assistive device project has incorporated the technology of voice recognition to perform the GSM calling. Arduino UNO is the microprocessor used to create an interface between the voice module and the GSM module SIM900. Platform was developed using inexpensive hardware and software elements available on the market People with disabilities showed high robustness for assistive device. Sample voice commands were stored in the temporary memory for the ATMEGA 328P when field tests with several sets of voice commands was done. The GSM module SIM900 could easily connect to the local cellular network carriers. Hence voice recognized emergency calling can be the future of biomedical field. </p>

<p> Current adhesives and gripping mechanisms used in many robotics applications function on very specific surface types or at defined attachment locations. A controllable, i.e. ON-OFF, adhesive mechanism that can operate on a wide range of surfaces would be very advantageous. Such a device would have applications ranging from robotic gripping and climbing to satellite docking and inspection/service missions. The main goal of the research presented here was to create such an attachment mechanism through the use of a new hybrid adhesive technology. The newly developed adhesive technology is a hybridization of electrostatic and micro-structured dry adhesion. The result provides enhanced robustness and utility, particularly on rough surfaces. There were challenges not only in the integration of these two adhesive elements but also with its application in a complete gripping mechanism.</p><p> Electrostatic and directional dry adhesives were both individually investigated. The electrode geometry for an electrostatic adhesive was optimized for maximum adhesion force using finite element analysis software. Optimization results were then verified through experimental testing. New manufacturing techniques were also developed for electrostatic adhesives that utilized a metalized mesh embedded in a silicone polymer and Kapton film based construction, greatly improving adhesion. The micro-structured dry adhesive used was provided by Dr. Aaron Parness, from the NASA Jet Propulsion Lab (JPL), and consists of an array of vertical stalks with an angled front face, referred to as micro-wedges. The hybrid electrostatic dry adhesive (EDA) was created by fabricating the electrostatic adhesive directly on top of a dry adhesive mold. This process created an array of dry adhesive micro-wedges directly on the surface of the electrostatic adhesive. In operation the electrostatic adhesive provides a normal force which serves to pull the dry adhesive into the surface substrate. With greater surface contact more of the dry adhesive is able to engage, bring the electrostatic adhesive even closer to the surface and increasing its effectiveness. Therefore, the combination of these two technologies creates a positive feedback cycle whose whole is often greater than the sum of its parts.</p><p> An interface mechanism is needed to transmit applied loads from a rigid structure to the flexible adhesive while still maintaining its conformability. This is especially important for strong adhesion on rough surfaces, such as tile and drywall. Different concepts such as a structured fibrillar hierarchy and a fluid-filled backing pouch have been explored. Additionally, finite element analysis was used to evaluate different fribrillar shapes and geometries for the structured hierarchy. The goal was to equalize the load distribution across the adhesive while still maintaining surface compliance. A gripper mechanism was also created which used a servo for actuation and three rigid tiles with a directional dry adhesive. It was tested on a perching Micro Air Vehicle (MAV) as well as in the RoboDome facility at NASA's Jet Propulsion lab to simulate a satellite docking/capture maneuver.</p>

<p>This dissertation explores bicycle dynamics through an extension of the Whipple bicycle model and validation of the model equations equations of motion through the implementation of a robotic bicycle. An extended Whipple bicycle model is presented which makes uses of a unique set of physical parameters based on cylindrical gyrostats. The nonlinear equations of motion for this model are derived, linearized, and validated against a set of benchmark model parameters. A general formulation for the linearization of a system with configuration and velocity constraints is presented, and is demonstrated on an idealized rolling disk. The method of linearization is directly applicable to the equations of motion which result from the application of Kane's method. The linearization procedure is used to formulate the linear state space equations of motion for the bicycle model, which are then used as the plant model to design the robotic bicycle control system. The mechanical, electrical, and software aspects of the robotic bicycle are presented, along with representative results from a set of experiments.

<p> Mobile robots are un-manned systems and must be able to overcome the obstacles they face without human intervention. In this research we have proposed a novel retractable mechanism which converts a linear hydraulic motion into expansion of six claws at each wheel. In order to control the expansion, optimal control theory was applied and a constrained optimization problem was defined using different Simulink toolboxes and applied to the mechanism modeled in SimHydraulics/SimMechanics. The main benefit of performing both hydraulic and mechanical system simulation and also control design in the same environment is to eliminate mathematical approximation of the model and using existing Simulink simulation tools for simulation and control. Systems were modeled and controller optimization was performed. Simulation results are illustrated at the end, which show the method's versatility and reliability for controlling the mechanism operation.</p>