This paper presents a comparison between two implementations of the elliptic curve cryptography (ECC) algorithm based on El-Gamal. Each implementation uses different cryptographic libraries: MIRACL and RELIC. The application of this algorithm meets the common needs of most critical embedded systems, focusing on unmanned aerial and ground vehicles (UAVs and UGVs) and addressing the particularities of each scenario, such as limitations of computing resources and energy supply. One of the challenges is to study and evaluate the impact of the use of each library via a performance evaluation based on statistical techniques. The results have presented the best solution and the influences of each algorithm on response times for each experiment, varying the sizes of keys used by the algorithms.
One alternative to overcome the presence of singularities within Parallel Manipulators’ workspace is kinematic redundancy. This design alternative can be realized by adding an extra active joint to a kinematic chain. Due to this addition, the IKM presents an infinite number of solutions requiring a redundancy resolution scheme. Moreover, Parallel Manipulators’ control may require complex strategies due to their coupled and complex dynamic and kinematic relations. In this work, a model-free, a joint space computed torque, and a hybrid joint-task-space computed torque control strategies are experimentally compared for a kinematically redundant parallel manipulator. The latter is a novel strategy that requires the measurement of the end-effector’s pose, which is performed by an eye-to-hand limited frame rate camera. The impact of up to three kinematic redundancy levels is also experimentally evaluated using prepositioning and ongoing positioning redundancy resolution schemes. The data are assessed by evaluating a prescribed trajectory executed using a planar kinematically redundant parallel manipulator. These results indicate that kinematic redundancy can not only be used as an alternative design for reducing the presence of singular regions, as claimed in the literature, but also be used along with model-based control strategies for improving dynamic performance and accuracy of parallel manipulators.
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