Unpower aerocraft augmented state feedback tracking guaranteed cost control

Aimed at designing the unpower aerocraft attitude control system in a simple and practical way, the guaranteed cost control is adopted. To eliminate the steady-error, a novel tracking control approach--augmented state feedback tracking guaranteed cost control is proposed. Firstly, the unpower aerocraft is modeled as a linear system with norm bounded parameter uncertain, then the linear matrix inequality based state feedback guaranteed cost control law is combined with the augmented state feedback tracking control from a new point of view. The sufficient condition of the existence of the augmented state feedback tracking guaranteed cost control is derived and converted to the feasible problem of the linear matrix inequality. Finally, the proposed approach is applied to a specified unpower aerocraft. The six dimensions of freedom simulation results show that the proposed approach is effective and feasible.

Unpowered Scooter-Related Injuries among Adolescents and Adults in the United States 2007-2017

United States Consumer Product Safety Commission (CPSC) reported a 700% increase in Emergency Department (ED) visits for injuries attributed to unpowered scooter use from January through October 2000. Our objective is to investigate injuries associated with the use of unpowered scooters among adolescents from the age of >9 years to 20 years in the National Electronic Injury Surveillance Study (NEISS) data set from 2007-2017. We analyzed unpowered scooter-related injuries in the NEISS data set using variables: SCOOTER, INJURED, AFTER, OFF, AT and IN;the product code for injuries related to unpowered scooters is 1329, and age ≥9 years and 9 - 19 - <99 years. Distribution by race: White 39.65%, Not Specified (NS) 38.94%, Black/African American 13.98% and Others (Asian, American Indians, Alaskan natives, Native Hawaiians, and Pacific Islanders) 7.43%. Body parts injured: head 16.19%, followed by face 8.49%, finger 8.30%, lower trunk 8.30%, ankle 5.60%, upper trunk 5.35%, internal injuries 0.99% and others 14.28%. Most of the injuries were mild: Treated and Discharged 89.80%, Hospitalized 7.68%, and Death in ED 0.05%. The locations of injuries were: Occurred at Home 43.47%, UNK 29.78%, Sports 12.63%, Public 6.49%, School 5.35%, and Street 2.22%. Injury trend: a rise until 2010, a decline until 2015 and, then a sharp rise through 2017. Injuries from the use of unpowered scooters are a rising threat that should be given attention. Outcome: Most of the injuries 69.80% were mild treated and discharged, 7.68% were hospitalized, while death in ED was 0.05%. Whereas: Transfer to referral hospital was about the same as in adults. Although most of these injuries were minor, head injuries could lead to more serious problems, and severe injuries could be life-threatening.

Designing Unpowered Shoulder Complex Exoskeleton via Contralateral Drive for Self-rehabilitation of Post-stroke Hemiparesis

Rehabilitation using exoskeleton robots can effectively remediate dysfunction and restore post-stroke survivors’ physical ability. However, low kinematic compatibility and poor self-participation of post-stroke patients in rehabilitation restrict the outcomes of exoskeleton-based therapy. The study presents an Unpowered Shoulder Complex Exoskeleton (USCE), consisting of Shoulder Girdle Mechanism (SGM), Ball-and-Socket Joint Mechanism (BSM), Gravity Compensating Mechanism (GCM) and Adjustable Alignment Design (AAD), to achieve self-rehabilitation of shoulder via energy transfer from the healthy upper limb to the affected counterpart of post-stroke hemiplegic patients. The SGM and AAD are designed to improve the kinematic compatibility by compensating for displacements of the glenohumeral joint with the adaptable size of USCE for different wearers. The BSM and GCM can transfer the body movement and energy from the healthy half of the body to the affected side without external energy input and enhance the self-participation with sick posture correction. The experimental results show that the USCE can provide high kinematic compatibility with 90.9% movement similarity between human and exoskeleton. Meanwhile, the motion ability of a post-stroke patient’s affected limb can be increased through energy transfer. It is expected that USCE can improve outcomes of home-based self-rehabilitation.

Sliding mode control based guidance law with impact angle constraint

The terminal guidance problem for an unpowered lifting reentry vehicle against a sta- tionary target is considered. In addition to attacking the target with high accuracy, the vehicle is also expected to achieve a desired impact angle. In this paper, a sliding mode control （SMC）-based guidance law is developed to satisfy the terminal angle constraint. Firstly, a specific sliding mode function is designed, and the terminal requirements can be achieved by enforcing both the sliding mode function and its derivative to zero at the end of the flight. Then, a backstepping approach is used to ensure the finite-time reaching phase of the sliding mode and the analytic expression of the control effort can be obtained. The trajectories generated by this method only depend on the initial and terminal conditions of the terminal phase and the instantaneous states of the vehicle. In order to test the performance of the proposed guidance law in practical application, numerical simulations are carried out by taking all the aerodynamic parameters into consideration. The effec- tiveness of the proposed guidance law is verified by the simulation results in various scenarios.