Shuttle Vehicle Research Articles

Airport Shuttle Vehicle Routing Optimization Model and Algorithm Based on Internet of Things

Airport Shuttle Vehicle Routing Optimization Model and Algorithm Based on Internet of Things

Anti-Overturning Capability and Fuzzy PID Speed Control for Four-Way Shuttle Vehicles in Processed Grain Storage

As the four-way shuttle vehicle is prone to overturning in finished grain storage during acceleration and deceleration, an overturning mechanical model is constructed. The design factors analyzed include grain bag height, vehicle and grain bag mass, and the type of grain’s effect on the vehicle’s anti-overturning stability. The critical overturning condition of the shuttle vehicle during operation is also determined as a result of this analysis. With the critical overturning condition, the speed control of the shuttle vehicle based on the fuzzy PID method is carried out to improve the anti-overturning stability. Significant details are made about the fuzzification of input and output variables, determination of membership function, establishment of the fuzzy rule base, fuzzy reasoning, and defuzzification. Finally, the comparative simulation model of fuzzy PID and conventional PID in the MATLAB/Simulink platform showed that the fuzzy PID control method had the advantages of fast convergence and quick response to the speed control of the four-way shuttle vehicle.

Scheduling quay cranes and shuttle vehicles simultaneously with limited apron buffer capacity

How to schedule quay cranes (QCs) and shuttle vehicles (SVs) simultaneously or model them in an integrated scheduling problem is one of the most important problems in operations and management of a container terminal. This paper investigates an integrated QC and SV scheduling problem constrained by apron buffer capacity. In this problem, the decisions to make include the bay-to-QC assignment, the QC-bay sequence, the QC-job sequence, the job-to-SV assignment and the SV-job sequence. First, a mixed-integer linear programming model is formulated for this problem to minimize the makespan. Second, the relationships and interactive variables among the four segments of constraints of the proposed model (i.e., scheduling QCs for vessel bays, sequencing jobs handled by a QC in each bay, scheduling SVs for jobs, apron buffer capacity constraints for each vessel bay) are analyzed to present three rules: vessel block rule, near-to-far rule and full-buffer rule. Finally, a sequential insertion algorithm, a greedy insertion algorithm and an improved genetic algorithm are proposed to solve mid- and large-sized cases for the problem. Numerical experiments show that the algorithms perform well, compared to the off-the-shelf solver. Based on these experiments, managerial implications are discussed for container terminal operations and management.

Integrated quay crane–shuttle vehicle scheduling problem capacitated by apron buffer

This paper investigates an integrated quay crane (QC)–shuttle vehicle (SV) scheduling problem (SP) with capacitated apron buffer, which is subject to practical constraints on non-zero travelling time, precedence relationships between container-handling jobs, QC non-interference, safety margin, blocking and apron buffer capacity. The objective is to minimise the makespan of vessel handling by simultaneous optimisation of bay-to-QC assignment, the sequences of bays handled by QCs, the sequences of jobs handled by QCs, job-to-SV assignment and the sequences of jobs handled by SVs. To achieve this, a mixed-integer linear programming model is first formulated to solve the SP. The relationships of decision variables and model constraints are then analysed to generate two sub-models: assignment based and sequence based. The former sub-model is developed from the proposed model by pre-determining the assignment of bay-to-QC and job-to-SV, and the latter is developed from the proposed model by pre-determining the sequences of jobs handled by each QC and each SV. Hybrid genetic algorithms with the two sub-models are proposed for numerical experiments. Practical implications of this investigation for apron buffer zone design are discussed.

A Real-time Schoolchild Shuttle Vehicle Tracking System Base on Android Mobile-apps

Indonesians parent widely use private school shuttle services for their schoolchild due to their lack of time and effectiveness, unfortunately mostly of those shuttle vehicles (car or motor cycle) services currently cannot be tracked. From a security point of view, the parent’s need a system that can identified the location of the vehicle in real-time. With rapid technological development today, parents' skepticism can be overcome by tracking the shuttle vehicles through a mobile applications that connected to Global Positioning System (GPS). This research presents the design of a prototype, called “AS-OJEK”, an android-based mobile apps and web technology for schoolchild shuttle applications that used several technology such as Web-services, JSON, PHP, MySQL and bootstrap framework as application builders. The application could be installed on any android smartphone version, it will be able to send the location and displaying the vehicle shuttle location on the smartphone screen and display historical location of the tracked vehicle. Rapid Application Development (RAD) framework was used as a software development method, with its 4 phases; phase 1: requirements planning and specifications, phase 2: user design, phase 3: construction, phase 4: cutover. The application was already appropriate with user’s needs, proven by performing functional testing and User Acceptance Test (UAT). Based on the results of the UAT, this application has been running well and succeed sending vehicle location to the server, and can tracked through mobile-apps or web applications.

Overview of acoustic and sonic boom advancements during development of NASA launch vehicles

During the study and development of NASA space vehicles, acoustic environments have been a critical design input. This paper surveys some of the key challenges and focuses on the contributions and collaborations of Kenneth J. Plotkin/Wyle Laboratories with various NASA centers and personnel. In the mid-1960’s and early 1970’s, a method for predicting in-flight fluctuating environments for vehicle systems was developed for the Saturn Development Programs at NASA Marshall Space Flight Center (MSFC). With the Space Shuttle Vehicle development in the 1970’s, sonic boom became a concern and sonic boom focusing was studied. Attention was turned to the Space Shuttle Orbiter entry maneuvers during the approach to the KSC landing site. In 1993, a PC version for sonic boom prediction was developed for the National Launch System study. Near-field pressure data from computational fluid dynamics analyses were used to develop the shape factors used in the X-33 sonic boom analyses. For the X-34 sonic boom analyses, the influence of plumes on the shape factor was included. In the 2000s, rocket noise prediction software at the KSC launch platform was developed for the Constellation Program. All this acoustic work is being leveraged on NASA’s latest vehicle, the Space Launch System.

Aerospace Meteorology: An Overview of Some Key Environmental Elements

The natural terrestrial environment plays a significant role in the design and operation of aerospace vehicles (space vehicles and rockets) and in the associated integrity of aerospace systems and elements. Addressed herein are some of the key vehicle and environment areas of concern plus lessons learned that have been identified over a number of years. Many of these aerospace meteorology related events occurred during the development and interpretation of natural environment inputs, especially those of terrestrial environment, used in the design and development of the Saturn Apollo and Space Shuttle vehicles plus associated mission operations. Background is given regarding the actions needed to avoid having to re-learn these lessons.

Planning for an Aging Fleet of Shuttle Vehicles with Simulation

San Francisco State University operates a small but aging fleet of shuttle vehicles that facilitate travel by its affiliates to, from, and around campus. Its shuttle system is primarily intended to supplement municipal bus service in connecting the university to the nearest Bay Area Rapid Transit train station in Daly City, California, approximately a mile and a half south of campus. This article presents an animated discrete-event simulation model of the system that can be used by campus planners to make capital improvement decisions about the fleet. In particular, the model can help identify the best type of shuttle (in terms of capacity and number of doors) to replace the older existing vehicles. Furthermore, experimentation with the model can predict how different fleet configurations would accommodate various increases in ridership; e.g., if ridership increases 40% over the next few years, a satisfactory level of service can be maintained by replacing just two of the fleet's six existing shuttles with new 39-passenger, two-door, low-floor vehicles.

Dynamics of contained liquids: A personal odyssey

Dynamics of contained liquids: A personal odyssey

Lunar Landing Craft for the Reusable Launch Vehicle and Shuttle Vehicles

Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.

Microbiology of the space shuttle water system

The Space Shuttle has a once-through water system that is initially filled on the ground, partially drained before launch and then refilled with fuel-cell generated water on orbit. The microbiological standard for the Space Shuttle potable water system during this study period allowed only 1 microbe of any kind per 100mL and no detectable coliforms. Contamination episodes in more than 15 years of Shuttle operation have been rare; however, for the past 24 missions, bacterial contamination has been detected in 33% of the samples collected 3d before launch. These samples have had on average 55CFU/100mL of bacteria, with the median less than 1CFU/100mL. Burkholderia cepacia has been the primary contaminant of the Shuttle water supply system both before and after flight. Water samples assessed during the STS-70 mission aboard the Space Shuttle Discovery were found to be contaminated (<20CFU/100mL) with B. cepacia and B. pickettii. In 1991, waste and water lines were removed from the Space Shuttle Columbia and the waste lines were found to harbor biofilms containing Bacillus spp. Nevertheless, the water systems of the four Space Shuttle vehicles provide extremely pure water.

Microbiology of the space shuttle water system

The Space Shuttle has a once-through water system that is initially filled on the ground, partially drained before launch and then refilled with fuel-cell generated water on orbit. The microbiological standard for the Space Shuttle potable water system during this study period allowed only 1 microbe of any kind per 100mL and no detectable coliforms. Contamination episodes in more than 15 years of Shuttle operation have been rare; however, for the past 24 missions, bacterial contamination has been detected in 33% of the samples collected 3d before launch. These samples have had on average 55CFU/100mL of bacteria, with the median less than 1CFU/100mL. Burkholderia cepacia has been the primary contaminant of the Shuttle water supply system both before and after flight. Water samples assessed during the STS-70 mission aboard the Space Shuttle Discovery were found to be contaminated (<20CFU/100mL) with B. cepacia and B. picketti. In 1991. waste and waterlines were removed from the Space Shuttle Columbia and the waste lines were found to harbor biofilms containing Bacillus spp. Nevertheless, the water systems of the four Space Shuttle vehicles provide extremely pure water.

New iterative method to solve optimal control problems with terminal constraints

Introduction T HE objective of this work is to present a new iterative method for solving optimal control problems with terminal constraints. The main idea in this work is to use a linear approximation to the state equations and a quadratic approximation to the cost functional, so that at each iteration efficient algorithms to solve linear quadratic (LQ) problems can be used to compute incremental corrections to the control signal, to make the terminal state approach the prescribed value. Many works on iterative techniques using second variations to solve optimal control problems can be found in the literature, including Refs. 1-3. The proposed scheme, however, differs from the neighboring extremal method because here the exact solution to an approximation is used in an iterative way, whereas Refs. 1-3 concern approximate solutions to the original nonlinear nonquadratic problem. The performance of the proposed method was studied in a number of examples, including a problem of atmospheric re-entry of Shuttle vehicles.

Calculation of Real-Gas Effects on Airfoil Aerodynamic Characteristics

The effects of high temperature thermochemical phenomena on the aerodynamic characteristics at hypersonic speeds are calculated for two-dimensional airfoils in air. The calculations are performed on an airfoil similar to that used for the Space Shuttle Orbiter, and ellipses of thickness ratios varying between 5 and 15 percent. For the airfoil, one flight condition is considered. For the ellipses, the calculations are carried out over a range of chord lengths, flight velocities, flight altitudes, and angles of attack. It is shown that the lift and drag coefficients are consistently reduced by the thermochemical phenomena, and that the behavior can be represented by a specific heat ratio value less than 1.4. The center of pressure shifts forward due to the thermochemical phenomena, but its extent is sensitively affected by the geometry and angle of attack and cannot be represented by a fixed specific heat ratio. The calculated results are in qualitative agreement with the data obtained during the entry flights of the Space Shuttle vehicle.

Enhancements of a three-dimensional hyperbolic grid generation scheme

A hyperbolic grid generation scheme formulated from grid orthogonality and cell volume specification has been significantly enhanced so that high quality three-dimensional grids can be obtained for a wide variety of geometries. While the speed of the scheme remains one to two orders of magnitude faster than typical elliptic grid generation methods, the robustness of the scheme has been greatly improved over previous applications of the three-dimensional hyperbolic grid generation procedure. Enhancements included the use of spatially-variable smoothing coefficient, metric correction procedures, local treatment of severe convex corners, and new extrapolation treatments of floating and axis boundaries. The versatility of the new hyperbolic grid generation scheme is demonstrated by three-dimensional grids generated for external components of the integrated Space Shuttle vehicle and the SOFIA telescope.

Middle atmosphere density data and comparison with models

Density data derived from measurements of the drag on twelve reentering Shuttle vehicles within the altitude range 40 to 97km have been compared with several models. There are no significant differences between the values of the several models, but the Shuttle data for a number of flights are significantly different from the models. Possible reasons for this are discussed. The variation of density with latitude is, in general, well represented by the models, but the seasonal dependence in the empirical models needs to be improved. Some flights show marked departures from the models at the higher altitudes (generally above 70km). Some possible causes of these departures, including convective activity and gravity waves, are discussed.

Recent concepts in missions to Mars - Extraterrestrial processes

This paper presents some recent concepts in Mars Sample Return (MSR) missions that utilize extraterrestrial resources. The concepts examined include the power and energy needs of this mission. It is shown that solar energy is not especially attractive. Radioisotopic power generator and a Rankine cycle use are seen to be viable options. Quantitative estimates, taking into consideration state-of-the-art and projected technologies indicate that the power/energy per se is not critical to the mission - but reliability is. Hence, various modern options for the components of the power generation and utilization are discussed. The dramatic savings in Shuttle (or other) vehicle launches are quantitatively plotted. The basic system that is discussed here is the production of hydrocarbon (methane) fuel and oxygen from Martian atmosphere. For the simplest mission, it is seen that earth-carried methane burned with oxygen produced on site provides the best system.

Launch processing system operations with a future look to operations analyst (OPERA)

The launch processing system at Kennedy Space Center is used to process a Shuttle vehicle from its initial arrival in an Orbiter processing facility to a launch pad. This paper describes the launch processing system architecture and the ground support operations required to provide Shuttle system engineers with the capability to safely process and launch an Orbiter. The described ground operations are the culmination of 11 years of experience and redesign. In this paper, I examine some of the “lessons learned” and discuss problem areas which ground support operations have identified over the years as the Shuttle and launch processing systems continue to grow in complexity. As we strive to maintain the efficient level of support currently provided, some benefits have been gained through standard information management and automation techniques. However, problems requiring complex correlational analyses of information have defied resolution until artificial intelligence research developed expert system applications technology. The operational analyst for distributed systems (OPERA), a proposed set of expert systems for launch processing system operational assistance, is discussed along with its extensions to prospective future configurations and components for the launch processing system.

Space Shuttle performance with a heads-up ascent

A method of increasing the space transportation system (STS) lift capability by flying the Space Shuttle vehicle in a heads-up, conventional airplane-piloting attitude during the first-stage atmospheric flight as opposed to the current heads-down attitude is presented. It is revealed that the STS lift capability and solid rocket motor burnrate definition are sensitive to the magnitude and direction of normal aerodynamic force acting on the Space Shuttle vehicle during atmospheric ascent. The STS operational trajectory design angle of attack will permit increases in the solid rocket motor (SRM) burnrate definition and STS lift capability for the proposed heads-up ascent when compared to the current heads-down ascent. For a heads-up ascent, the SRM burnrate can be increased 7% with a corresponding 4000 Ib increase in STS lift capability. A comparison of the heads-up and heads-down ascent reveals similar performance trades for changes in trajectory-shaping parameters, SRM and Space Shuttle main engine (SSME) performance characteristics.

Trends in space transportation

Near-future goals of international launch systems are aimed at placing payloads of at least 5000 kg into geosynchronous earth orbit (GEO). In the United States, this will be accomplished by the Shuttle with a new upper stage and complementary expendable launch vehicle (CELV) such as the Titan 34D7/Centaur. The Soviet Union's efforts will also achieve this goal and the European Space Agency's (ESA) Ariane 5 will approach it. It appears clear that the U.S. will revert to a mixed fleet policy, utilizing the Shuttle only for those missions where its capacity is needed or where manned presence is a necessity. The ESA Hermes and the Soviet shuttle will also be chiefly used in the latter capacity. In the United States and the Soviet Union, much thought and some funds are being devoted to the study of third-generation space transportation systems. The objectives are to achieve either/or ready access to space, low cost per pound to orbit, and very heavy weights (at low cost/pound) to orbit. Concepts such as the AerospacePlane and HOTOL (horizontal take-off and landing); the Shuttle-derived vehicles (SDV), and mammoth heavy lift launch vehicles (HLLVs) are being studied. The third generation of launch vehicles will serve both civilian and military needs. Civilian applications represent a myriad of advanced needs. They range from the normal extension of present communications, earth observations, in-space manufacturing, and space station and other manned operations to the more exotic missions of Mars expeditions (both manned and unmanned), lunar bases, and large space-based power systems. Military applications are likely to include advanced intelligence and reconnaissance systems, spacecraft servicing and maintenance tasks, support of the Strategic Defense Initiative (SDI) systems, and possibly a permanent manned presence in space. Both civil and military aims may lead to the development of the AerospacePlane. This vehicle could evolve into forms designed for high speed air and space transportation and flexible response missions. This paper describes the present thinking and early plans of medium launch vehicles, advanced shuttles, and AerospacePlane-type vehicles. Shuttle-derived and heavy-lift earth to low orbit systems are discussed, along with the ESA/Centre National d'Etudes Spatiales (CNES) Hermes and Soviet shuttle concepts.