Indirect-Neural-Approximation-Based Fault-Tolerant Integrated Attitude and Position Control of Spacecraft Proximity Operations.

In this paper, a neural adaptive fault-tolerant control scheme is proposed for the integrated attitude and position control of spacecraft proximity operations in the presence of unknown parameters, disturbances, and actuator faults. The proposed controller is made up of a relative attitude control law and a relative position control law. Both the relative attitude control law and relative position control law are designed by adopting the neural networks (NNs) to approximate the upper bound of the lumped unknowns. Benefiting from the indirect neural approximation, the proposed controller does not need any model information for feedback. In addition, only two adaptive parameters are required for the indirect neural approximation, and the online calculation burden of the proposed controller is therefore significantly reduced. Lyapunov analysis shows that the overall closed-loop system is ultimately uniformly bounded. The proposed controller can ensure the relative attitude, angular velocity, position, and velocity stabilize into the small neighborhoods around the origin. Lastly, the effectiveness and superior performance of the proposed control scheme are confirmed by a simulated example.

Management of Knee Flexion Contracture in a Child With 3MC Syndrome Using Taylor Spatial Frame.

3MC syndrome is a rare genetic disorder inherited through an autosomal recessive inheritance pattern caused by mutations in one of three genes: COLEC11, COLEC10, and MASP1. High-arched brows, ptosis, blepharophimosis, hypertelorism, cleft lip, cleft palate, developmental delay, hearing loss, abdominal wall defect, and urogenital and skeletal abnormalities are all characteristics. In previous reports, involvement of knee flexion contracture was not known to be one of the 3MC syndrome symptoms. The prevalence of 3MC syndrome is still unknown, and there have only been a few reports. We report the case of a four-year-old female with 3MC syndrome who was diagnosed with a confirmed mutation in the COLEC11 gene. We describe a method for decreasing knee flexion contracture in a reported patient that makes use of the Taylor spatial frame (TSF). Accepted results were observed because the patient has full extension, which must be maintained by the brace. According to our findings, the TSF was the safest, most accurate, stable fixator, and most efficient solution for treating knee flexion contracture, resulting in high patient and family satisfaction.