Force Command Research Articles

Gerenciamento de Recursos da Tripulação - Fator de Prevenção de Acidentes

The article "Crew Management: Accident Prevention Factor" discusses the evolution of Crew Resource Management (CRM) in aviation, emphasizing its relevance in reducing air accidents. Since the 1980s, CRM has been implemented to enhance communication and collaboration among crew members, aiming to minimize human error, which is a major factor in accidents. The text discusses the different generations of CRM, from the first, focused on the cockpit, to the fourth, which encompasses the entire crew and external resources. Despite the initiatives of the Air Force Command, such as courses and training, there are still challenges in standardizing and adopting CRM across all air units. The article concludes that including CRM in the training curriculum for aviators is essential to disseminate this doctrine and reduce the occurrence of human errors.

Control allocation optimization for an over-actuated tandem tiltwing eVTOL aircraft considering aerodynamic interactions

This paper describes control allocation strategies for a tandem tiltwing electric vertical take-off and landing (eVTOL) aircraft with distributed propulsion. The control mappings are constructed as local surrogate models that relate the control effectors to the aircraft's aeropropulsive forces and moments across the full flight envelope, including interactional aerodynamics effects. Control allocation optimization problems are formulated based on force and moment commands for specific flight conditions. Specifically, a nonlinear programming formulation based on nonlinear control mapping is proposed for control allocation optimization, and the problem is solved using a sparse nonlinear optimizer. The solutions obtained from different formulations such as the minimization of force and moment residuals and the minimization of control effort are investigated. Furthermore, these solutions are compared with the solutions obtained using linear control mapping-based formulations. Results presented for the cases of forward flight, low speed flight & hover, and flight in the transition corridor suggest that considering aerodynamic interactions while formulating and solving the control allocation problem is necessary for higher levels of accuracy compared to linear approaches. One-propeller-out scenarios and moment and force generation cases are also investigated. Finally, control allocation for steady and accelerated operation in the transition corridor is discussed. The contribution of the methods and results in the paper is a nonlinear control allocation methodology for the entire flight envelope of an over-actuated tandem tiltwing eVTOL aircraft.

Geometric optimal filtering for an articulated n‐trailer vehicle with unknown parameters

AbstractIn this article, we consider the equations of motion for an articulated ‐trailer vehicle with different masses and inertias in the presence of force and torque commands. We design a second‐order optimal filter to estimate the pose of the first vehicle and of the trailers exploiting the Lie group structure and the nonholonomic and hooking constraints. We consider the filtering problem from three different perspectives: in the first masses and inertias are time‐varying and perfectively known, in the second they are known only in the first part of the maneuver, but they are not updated over time. In the last case masses and inertias are considered within the state vector and therefore estimated by the filter. Depending on the needs in real‐life applications (e.g., whether the masses and inertias remain fixed or change during the maneuver and are unknown), the best‐performing filter can be used. The sensing system consists of a GPS‐like configuration (global positioning system) obtained by using an antenna attached to the leading car.

Hronika Velikoj Pobedy (1941–1945) 22 iyunya 1941 g.

“Voprosy Istorii” history journal presents documents within our Chronicle of the Great Victory (19411945). The current issue contains documents related to the situation on the Southwestern Front on June 22,1941. This is the operational summary No. 01 on the situation at 22:00. It was signed by the Chief of Staff of the Southwestern Front, Lieutenant General M.A. Purkaev and the head of the operational department of the Southwestern Front, Major General I.Kh. Bagramyan. The second document is an operational summary of the Air Force Headquarters on the situation in the area of responsibility of the Air Force Command. It was signed by the Chief of Staff of the Front Air Force, Colonel N.A. Tygrebert and the head of the operational department of the Front Air Force Headquarters, Major S.A. Vladimirov. The documents are contained in Central Archive of the Ministry of Defense of the Russian Federation.

NEW APPROACH TO MILITARY PILOT EDUCATION AND TRAINING IN THE NEW SECURITY ENVIRONMENT

Military pilot education, including flight training, is a long, expensive, and complex process. The main goal is to produce as many skilled professionals as possible ready to perform flight tasks on the front-line aircraft and push them to their workload limits with complete control. To achieve this goal, it is necessary to select and educate young people with the aptitude and abilities to perform the most demanding military flight tasks. The creation of a model for the education and training of military pilots depends on the requirements of the Czech Air Force Command and the teaching capacities of the University of Defence and the Aviation Training Centre in Pardubice. Rearmament of the Czech Air Force and the required number of pilots requires a change in the new military pilot training model. This contribution describes a new approach to Czech Air Force pilot education and training in the current security conditions in the world.

80 Years since the Repatriation of British and American Prisoners from Romania

As Romania joined the Allied Powers (23 August 1944), the fate of American and British prisoners became uncertain, as they were in danger of either being captured by German troops or falling into the hands of the Red Army. As the archive documents show, at that time, there were 1,262 prisoners (1,123 American and 39 British) in Romania, interned in camp no. 13 Bucharest (Pedagogical School on “Sfânta Ecaterina” Street and “Regina Elisabeta” Military Hospital) and camp no. 14 Timișu de Jos1. In the rescue operation, with the support of the Romanian authorities, Lieutenant Colonel James Gunn was transported by a plane, piloted by Captain Constantin Bâzu Cantacuzino, in Bari, Italy, where the 15th Air Force Command was located. All American and British prisoners in Romania were transported to Italy during Operation Reunion, organised by the 15th Air Force, on 31 August, 1 September, and 3 September 1944.

80 de ani de la repatrierea prizonierilor americani și britanici din România

As Romania joined the Allied Powers (23 August 1944), the fate of American and British prisoners became uncertain, as they were in danger of either being captured by German troops or falling into the hands of the Red Army. As the archive documents show, at that time, there were 1,262 prisoners (1,123 American and 39 British) in Romania, interned in camp no. 13 Bucharest (Pedagogical School on “Sfânta Ecaterina” Street and “Regina Elisabeta” Military Hospital) and camp no. 14 Timișu de Jos1. In the rescue operation, with the support of the Romanian authorities, Lieutenant Colonel James Gunn was transported by a plane, piloted by Captain Constantin Bâzu Cantacuzino, in Bari, Italy, where the 15th Air Force Command was located. All American and British prisoners in Romania were transported to Italy during Operation Reunion, organised by the 15th Air Force, on 31 August, 1 September, and 3 September 1944.

Vision-based adaptive LT sliding mode admittance control for collaborative robots with actuator saturation

Abstract In this paper, we propose a novel vision-based adaptive leakage-type (LT) sliding mode admittance control for actuator-constrained collaborative robots to realize the synchronous control of the precise path following and compliant interaction force. Firstly, we develop a vision-admittance-based model to couple the visual feedback and force sensing in the image feature space so that a reference image feature trajectory can be obtained concerning the contact force command and predefined trajectory. Secondly, considering the system uncertainty, external disturbance, and torque constraints of collaborative robots in reality, we propose an adaptive sliding mode controller in the image feature space to perform precise trajectory tracking. This controller employs a leakage-type (LT) adaptive control law to reduce the side effects of system uncertainties without knowing the upper bound of system uncertainties. Moreover, an auxiliary dynamic is considered in this controller to overcome the joint torque constraints. Finally, we prove the convergence of the tracking error with the Lyapunov stability analysis and operate various semi-physical simulations compared to the conventional adaptive sliding mode and parallel vision/force controller to demonstrate the efficacy of the proposed controller. The simulation results show that compared with the controller mentioned above, the path following accuracy and interaction force control precision of the proposed controller increased by 50% and achieved faster convergence.

Investigation of Legendre polynomials expanded adaptive controller with inverse compensation for high frequency tracking of electro-hydraulic force systems

Accurate force tracking of an electro-hydraulic force system (EHFS) is of great significance in various industrial applications. As the EHFS is inevitably confronted with hydraulic nonlinearities, dynamic variations and uncertain disturbances, the real-time force tracking performance is generally unsatisfactory, especially for high frequency command force signals. For reducing the force tracking error with relatively high frequency inputs, a Legendre polynomials expanded adaptive controller with inverse compensation is proposed in this paper. The proposed controller is constructed by introducing an offline designed inverse compensation (IC) controller and an online adaptive controller to the EHFS governed by traditional Proportional Integral (PI) controller, in which the former IC controller is acting as the inner loop controller and the latter adaptive controller is regarded as an outer controller. The inner loop IC controller with fixed control parameters is offline designed on the basis of traditional PI controller by means of the generalized projection identification algorithm and the zero magnitude error tracking technology, focusing on extending the real-time force tracking bandwidth of the EHFS. The outer loop online adaptive controller is developed by Legendre polynomials expanded adaptive filters with nonlinear mapping ability, whose weights are online updated by an adaptive tuning algorithm with the aim of handling system’s dynamic variations, nonlinearities and uncertain disturbances. The proposed controller is implemented on a real EHFS test rig by the xPC/Target rapid prototyping technique, and comparative experimental results demonstrate that the proposed controller can achieve much higher high frequency tracking performance than the traditional PI and IC controller commonly used in industry.

Explicit Model Predictive Cascade-Free Direct Force and Torque Control of Quadrotors

High-performance control of quadrotors' force and torques is the basis for achieving excellent trajectory tracking. However, the conventional method indirectly controls the force and torques by controlling four permanent magnet synchronous motors' speeds, resulting in poor dynamic performance and static deviations when pneumatic parameters mismatch. Dedicated to achieving high-dynamic and high-accuracy control of force and torques, an explicit model predictive (EMP) cascade-free direct force and torque control method is proposed. Firstly, defining force current and torque currents, whereby a new structure is proposed. Then, dynamics of the quadrotor and motor are fused to design the linear robust predictive models of force and torques. Accordingly, the EMP controller is constructed to replace the traditional cascaded speed solution module and four speed controllers uniformly. The EMP controller generates the optimal current commands directly from the force and torque commands, realizing direct control without the speed loop. The new structure makes it possible to solve the pneumatic parameter mismatch problem with an auxiliary extended state observer, obtaining offset-free control. The proposed method optimizes the dynamic performance and steady-state accuracy of force and torques and improves the system's robustness. Finally, the proposed method's feasibility is verified by experiments.

Deep reinforcement learning‐based active mass driver decoupled control framework considering control–structure interaction effects

AbstractControl–structure interaction (CSI) plays a significant role in active control systems. Popular methods incorporate actuator dynamics into an integrated control system to account for CSI, leading to a situation where existing structural control algorithms that ignore CSI cannot be applied directly. To address this issue, this study proposes a deep reinforcement learning (DRL) based active mass driver (AMD) decoupled control framework, in which a structural control algorithm is employed to generate the control force command without consideration of CSI, while a DRL agent is utilized to attenuate the CSI effects of AMD systems and achieve a desired control force. The DRL‐based AMD control framework is verified through a series of numerical experiments. Furthermore, the applicability of the control framework is confirmed in a wind‐excited 76‐story benchmark building. Comprehensive analysis indicates that the proposed control framework can effectively eliminate the CSI effects and apply accurate control force to the structure in various scenarios, which allows for an ideal structural response control.

SPORTS AVIATION IN THE WORLD AND YUGOSLAVIA AFTER SECOND WORLD WAR

After World War II, the accelerating demand for personal and utility aircraft gave rise to the term general aviation to describe all flying that did not fall into the category of military or scheduled air transport. Immediately before the liberation, the first aviation organization in Yugoslavia was formed in Zemun in 1944. In March 1945, the Air Force Command established the Gliding Center in Vršac, and in April classes for the first class of gliding teachers began. The first aero-clubs began to operate within the Commission for Technology and Sports, at the beginning of 1946 (later Narodna tehnika). The Aviation Association of Yugoslavia (Vazduhoplovni savez Jugoslavije – VSJ) was founded on April 25, 1948 in Belgrade. In 1950, he renewed his membership in the FAI, was unanimously accepted as a member at the 43rd general conference held in Stockholm.

The evolution trend and thinking of the modernization of command, control and communication system of American nuclear force

The nuclear force Command, Control and Communication System (NC3) is a variety of facilities required when the president issues nuclear operations instructions, is the central nervous system to achieve the United States "trinity" strategic nuclear strike, and is an important basis for achieving reliable and effective nuclear deterrence. The future contest between major powers is a comprehensive confrontation based on the comprehensive national strength of strategic nuclear forces. While the United States has the world's most advanced conventional combat forces and the largest nuclear Arsenal, it continues to apply new technological means to improve the operational command and control system of nuclear forces, upgrade its nuclear Arsenal, strengthen the construction and development of nuclear forces, and maintain its nuclear superiority. We should draw inspiration from this and speed up the independent research and development of a credible and reliable combat command system of nuclear forces to ensure that we will win the first opportunity in future wars.

Vision-admittance-based adaptive RBFNN control with a SMC robust compensator for collaborative parallel robots

This paper proposes a novel vision-admittance-based adaptive neural network control method for collaborative parallel robots tracking a predefined trajectory and force command. First of all, the vision-admittance model is creatively developed for coupling visual information and force-sensing information in the image feature space and is applied to generate the image feature reference trajectory online according to the desired trajectory and the command of the interaction force. Secondly, considering the system modelling uncertainties and external disturbances, an adaptive Radial basis functions neural network (RBFNN) controller is created to realize high-precision trajectory tracking. The adaptive tuning laws are designed based on the Lyapunov stability theorem so that the entire system’s stability and the convergence of the weight adaptation can be guaranteed. Moreover, a sliding mode control (SMC)-based robust compensator is added to the RBFNN controller as an auxiliary term to improve the robustness and stability of the control system. Finally, co-simulations between ADAMS/Simulink are performed on a collaborative Five-bar parallel robot to demonstrate the efficacy of the proposed controller.

From Trainee to Adapter: A Mapping of Leadership Competencies of Adapter Cadet in the Air Force Academy

The beginning of military training of those who join the Armed Forces is one of the most important stages of their professional lives. At the Air Force Academy (AFA), this period is known as the Military Adaptation Internship (EAM), and demands a lot of dedication of the candidates, called trainees, and of the Officers of the Cadet Corps Command, who are responsible for adapting inexperienced young people to the new and strenuous routine. In order to carry out such a challenge, it is necessary that the Officers should be assisted by a group of cadets to conduct the various activities that will positively influence the trainees during their first days in the barracks. These cadets, now called as adapters, are chosen by their Squadron Command through a selection process that should occur as uniformly as possible. In order to provide such an important service, it is essential that the adapters are properly trained, as they will reflect on their subordinates the main attributes of an Air Force cadet and serve as a reference to them. However, it is noted that nowadays, the selection process for adapters is not formally standardized. In this sense, the objective of this work is to contribute to the mapping of the competencies that the adapter cadet needs to have developed by the beginning of the EAM, in order to better fulfill the tasks to which he/she will be assigned during this internship. The transactional leadership theory will serve as the basis for identifying knowledge, skills and attitudes in the cognitive, affective and psychomotor fields of the students, in order to explain the importance of each one. The methodology consists of an applied, descriptive and explanatory research, using a questionnaire with the Officers of the Squadron Commands of AFA, to analyze the sample of competencies to be suggested and implemented. In addition, it was done a bibliographic review of the most relevant articles, books and academic works on the subject, and paying special attention to the publications of the Air Force Command that deal with the issues at hand. At the end of this research, the main aspects of an adapter cadet were highlighted, emphasizing the meaning of each item and how it can assertively reflect on the career of a future officer of the Brazilian Air Force.

Multifingered Robot Hand Compliant Manipulation Based on Vision-Based Demonstration and Adaptive Force Control.

Multifingered hand dexterous manipulation is quite challenging in the domain of robotics. One remaining issue is how to achieve compliant behaviors. In this work, we propose a human-in-the-loop learning-control approach for acquiring compliant grasping and manipulation skills of a multifinger robot hand. This approach takes the depth image of the human hand as input and generates the desired force commands for the robot. The markerless vision-based teleoperation system is used for the task demonstration, and an end-to-end neural network model (i.e., TeachNet) is trained to map the pose of the human hand to the joint angles of the robot hand in real-time. To endow the robot hand with compliant human-like behaviors, an adaptive force control strategy is designed to predict the desired force control commands based on the pose difference between the robot hand and the human hand during the demonstration. The force controller is derived from a computational model of the biomimetic control strategy in human motor learning, which allows adapting the control variables (impedance and feedforward force) online during the execution of the reference joint angles. The simultaneous adaptation of the impedance and feedforward profiles enables the robot to interact with the environment compliantly. Our approach has been verified in both simulation and real-world task scenarios based on a multifingered robot hand, that is, the Shadow Hand, and has shown more reliable performances than the current widely used position control mode for obtaining compliant grasping and manipulation behaviors.

Model-Based Adaptive Collaboration of Multi-Terminal Internal Force Tracking

This paper proposes a multi-terminal adaptive collaborative operation method for solving the problem of unstable internal force tracking in the clamping and handling of unknown objects by multi-terminal robots. In the proposed method, the internal command force changes the complex internal force control problem into an internal force tracking problem from multi-slave to master. Moreover, we develop an algorithm for multi-slave setups to estimate the object stiffness and motion uncertainty in the direction of the internal command force according to Lyapunov theory. Finally, the impedance control generates a reference trajectory for the multi-slave to maintain the desired internal force and track the master’s motion. Several experiments were conducted on a self-made robot. The experimental results show that the oscillation amplitude of each slave end is less than 1 mm and the directional oscillation amplitude is less than 1 degree during the tracking of the desired commanded internal force. For objects with a low stiffness, the error of the commanded internal force is less than 1 N (6%) per slave. The error in tracking the commanded internal force for objects with a high stiffness is less than 2 N (8%). The results prove the feasibility and effectiveness of the proposed method.

LQR force command planning–based sliding mode control for active suspension system

In this article, a linear quadratic regulator (LQR)-based sliding model control strategy was proposed for the commercial vehicle seat suspension system. First, the multiple degrees of freedom mechanical dynamics model of a quarter suspension system was built. Then, the LQR force command planner was designed based on mechanical dynamics to ensure driver comfort. Second, considering the mechanical dynamics augmented with hydraulic actuator dynamics, a proportional-integral sliding mode control strategy was developed to track the reference force, which was calculated by the LQR force command planner in real time. Taking the problems of noise disturbances and unavailable full states feedback into consideration, the Kalman filter and tracking differentiator were designed and integrated into the control algorithm. Finally, the quarter suspension AMESim model was built, and the proposed control strategy was implemented and verified in the AMESim-Matlab/Simulink co-simulation environment. Comprehensive simulations were carried out. The simulation results, both from time domain and frequency domain perspective, indicated that the seat ride comfort can be effectively improved with the proposed method.

Visual-admittance-based model predictive control for nuclear collaborative robots

This paper presents a novel visual-admittance-based model predictive control scheme to cope with the problem of vision/force control and several constraints of a nuclear collaborative robotic visual servoing system. A visual-admittance model considering the desired image feature and force command in the image feature space is proposed. Moreover, a novel constraint scheme of the model predictive control (MPC) is proposed to cancel the overshoot in the interaction force control for most cases by taking the desired force command as the constraint of the proposed MPC. Via applying the robotic dynamic image-based visual servoing (IBVS) model, some other constraints, such as the actuator saturation, joint angle, and visual limits, can be satisfied simultaneously. The simulation results for the two-degrees-of-freedom (DOF) robot manipulator with an eye-to-hand camera are present to demonstrate the effectiveness of the proposed controller.

Brytyjskie formacje konne na półwyspie Gallipoli w 1915 roku

The fighting on the Gallipoli peninsula in 1915 was primarily a clash of masses of infantry. The limited area controlled by the allies and difficult terrain basically prevented the effective use of cavalry. Nevertheless, after a few weeks, the first cavalry units landed on the peninsula. Over the following months, their number systematically grew. At its peak, the composition of the British forces included as many as 15 horse brigades. Armament, equipment, and above all, the principles of training allowed it to fight in the same way as infantry. It was used to man field fortifications at the front or to strengthen the most weakened infantry divisions. Sending horse formations to the peninsula was irrational. Using such formations as infantry deprived them of their main advantage, which was mobility. What's more, positional fighting caused significant losses, even in a situation of relative calm on the front. In addition, problems with provisions and hygiene caused increasing non-combat losses. In the fall, these problems only increased. The Mediterranean Expeditionary Force Command was aware of these problems. It even attempted to obtain additional infantry units from Egypt to replace the cavalry on the peninsula. Unfortunately, personal animosities, competition and lack of strategic thinking meant that these intentions were not implemented.