Entry vehicle control system design for the Tianwen-1 mission

The entry vehicle for the Tianwen-1 mission successfully landed on the surface of Mars at 7:18 AM BJT on May 15, 2021. This successful landing made China the first country to orbit, land, and release a rover in their first attempt at the Mars exploration. The guidance, navigation, and control (GNC) system plays a crucial role in the entry, descent, and landing (EDL) phases. This study focused on the attitude control component of the GNC system design. The EDL phase can be divided into several sub-phases, namely the angle of attack control phase, lift control phase, parachute descent phase, and powered descent phase. Each sub-phase has unique attitude control requirements and challenges. This paper introduces the key aspects of designing attitude controllers for each phase. Furthermore, flight results are presented and analyzed.

A trim problem formulation for maximum control authority using the Attainable Moment Set geometry

This paper presents a generic trim problem formulation, in the form of a constrained optimization problem, which employs forces and moments due to the aircraft control surfaces as decision variables. The geometry of the Attainable Moment Set (AMS), i.e. the set of all control forces and moments attainable by the control surfaces, is used to define linear equality and inequality constraints for the control forces decision variables. Trim control forces and moments are mapped to control surface deflections at every solver iteration through a linear programming formulation of the direct Control Allocation algorithm. The methodology is applied to an innovative box-wing aircraft configuration with redundant control surfaces, which can partially decouple lift and pitch control, and allow direct lift control. Novel trim applications are presented to maximize control authority about the lift and pitch axes, and a “balanced” control authority. The latter can be intended as equivalent to the classic concept of minimum control effort. Control authority is defined on the basis of control forces and moments, and interpreted geometrically as a distance within the AMS. Results show that the method is able to capitalize on the angle of attack or the throttle setting to obtain the control surfaces deflections which maximize control authority in the assigned direction. More conventional trim applications for minimum total drag and for assigned angle of elevation are also explored.

Smartphone Operated Elevator

additionally as an interface as a connection among cell phones and lift control boards. Moreover, we'll show the arrangement of the apparatus which animates an effect board for the lift call and interface which can get signals, measure them and send them to the fundamental lift instrument board. The introduced framework may be used in shrewd house projects and, particularly for crippled individuals. The common link change framework includes a long change cycle on the change of level floor, running bends, and including running parts for the lift. Then again, it generally requires close coordination between two agents. So this paper plans a lift remote change framework, including Bluetooth innovation, Android telephone innovation, and microcontroller innovation. The lift remote change framework makes the technique for change natural, decreases the responsibility of the adjustor, and speeds up the lift change cycle. Contrasted to the typical lift change strategy, this procedure makes it conceivable to utilize an Android telephone as a lift change apparatus to troubleshoot the lift with Bluetooth. Other than contrasted and other remote lift change strategies, the remote module is fixed on the regulator for the lift as opposed to the lift regulator, this technique maintains a strategic distance from the restriction of remote distance and subsequently, the adjustor simply should remain inside the lift while changing the boundary of the lift instead of running here and there, the continuous change result's fit to be seen inside the Android telephone. The test has demonstrated the achievability, viability, and dependability of the plan of a lift remote change framework.

Adaptive fuzzy direct lift control of aircraft carrier-based landing

Considering the precise landing demand for carrier-based aircraft flight control, this paper proposes an adaptive fuzzy landing control method for the strong time-varying, parameter uncertainty and various complex coupling in the actual state aircraft model. This method is applied to the flap channel to achieve direct lift control, and the fuzzy system is utilized to approximate the six-degree-of-freedom nonlinear system model of a carrier aircraft that is difficult to accurately describe, to achieve accurate tracking of the landing glideslope, and improve the landing accuracy. Lyapunov method was used to judge the stability of the adaptive fuzzy control algorithm. During the simulation, the airwake and deck motion disturbance were introduced to simulate the landing environment of the aircraft. The effectiveness of the landing control system was verified by the Matlab software. Monte-Carlo random test was utilized to carry out the landing point accuracy for the conventional control scheme and the adaptive fuzzy direct lift control scheme respectively. Through the response curve and landing point statistical results, it is confirmed that the direct lift control scheme has better control effect, and the landing precision has improvement compared with the conventional control scheme.

The Future of Plunger Lift Control Using Artificial Intelligence

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201132, “The Future of Plunger Lift Control Using Artificial Intelligence,” by Ferdinand Hingerl and Brian Arnst, SPE, Ambyint, and David Cosby, SPE, Shale Tec, et al., prepared for the 2020 SPE Virtual Artificial Lift Conference and Exhibition - Americas, 10-12 November. The paper has not been peer reviewed. Dozens of plunger lift control algorithms have been developed to account for different well conditions and optimization protocols. However, challenges exist that prevent optimization at scale. To address these challenges, a plunger lift optimization software was developed. One aspect of this software is enabling set-point optimization at scale. This paper will present the methodology to do so, detailing three separate areas working in unison to offer significant value to plunger lift well operators. Introduction Even in vertical wells, plunger lift presents significant challenges to optimization. Despite their mechanical simplicity, plunger lifted wells produce large amounts of data, and the combinations of possible set points to optimize the well are many. Additionally, plunger lift wells can present a variety of different types of anomalies and problems that require a robust understanding of the underlying physics and mathematics. Such problems then are amplified when applied to horizontal well applications. The underlying physics and mathematics applied throughout the years for vertical wells do not produce accurate results for horizontal wells. Additionally, the anomalies produced in horizontal wells are more complex. Finally, typical production engineers and well optimizers now regularly look after more than 150—and often more than 500—wells, creating additional resource constraints to optimizing a field of plunger lift wells. The presented plunger lift optimization software was implemented by creating a secure connection between the operator’s supervisory control and data acquisition (SCADA) network and the cloud. As new data are generated by the SCADA network, they are automatically transmitted to the cloud and processed. Plunger Lift Control Algorithm Overview These algorithms are the software code that determines when the well opens and when the well closes. Even though the algorithms only control well open/close, the plunger moves through four stages of plunger operation to complete one cycle: plunger fall time, casing pressure build time, plunger rise, and after flow (or production). Optimizing each individual stage is critical to ideal well production. Plunger fall time is the time required for the plunger to descend from the lubricator to the bottomhole assembly (BHA). Currently, operators use the manufacturer’s anticipated fall time, trial and error, previous knowledge, acoustical plunger tracking, and plunger fall applications to set the appropriate fall time in the controller. A “fudge factor” is often applied to help ensure that the fall timer does not expire before the plunger reaches the BHA. Plunger fall time is affected by many changing variables: plunger condition, tubing condition, liquid height, and gas and liquid density. These variables make it difficult for a fall timer set once to represent accurately the correct time required for the plunger to reach the BHA on every cycle.

A Generalized Approach to Operational, Globally Optimal Aircraft Mission Performance Evaluation, with Application to Direct Lift Control

A unified approach to aircraft mission performance assessment is presented in this work. It provides a detailed and flexible formulation to simulate a complete commercial aviation mission. Based on optimal control theory, with consistent injection of rules and procedures typical of aeronautical operations, it relies on generalized mathematical and flight mechanics models, thereby being applicable to aircraft with very distinct configurations. It is employed for an extensive evaluation of the performance of a conventional commercial aircraft, and of an unconventional box-wing aircraft, referred to as the PrandtlPlane. The PrandtlPlane features redundant control surfaces, and it is able to employ Direct Lift Control. To demonstrate the versatility of the performance evaluation approach, the mission-level benefits of using Direct Lift Control as an unconventional control technique are assessed. The PrandtlPlane is seen to be competitive in terms of its fuel consumption per passenger per kilometer. However, this beneficial fuel performance comes at the price of slower flight. The benefits of using Direct Lift are present but marginal, both in terms of fuel consumption and flight time. Nonetheless, enabling Direct Lift Control results in a broader range of viable trajectories, such that the aircraft no longer requires cruise-climb for maximum fuel economy.