Cruise Mode Research Articles

A Peripherally-Located Virtual Instrument Landing Display Affords More Precise Control of Approach Path during Simulated Landings than Traditional Instrument Landing Displays

We compared the precision of simulated fixed-wing aircraft landing approaches with three different head-up display (HUD) formats: a) MIL-STD-1787B Cruise Mode, b) MIL-STD-1787B Instrument Landing System (ILS) Mode, and c) a virtual ILS HUD presented to the visual periphery. Non-pilot participants used simplified controls to guide a landing simulation under both day and night visual meteorological conditions. Experiment 1 confirmed that testing non-pilots with our experimental setting could induce the black-hole illusion, in which the approach is lower than appropriate at night. Experiment 2 compared landing performance aided by the three HUD formats under the same visual conditions. We found that both ILS displays improved approach path precision as compared to the MIL-STD Cruise Mode, and that the peripherally-located virtual ILS HUD reliably afforded the greatest precision. These results suggest that ILS approaches may be better supported by presenting a virtual ILS display to the visual periphery.

Effect of Advanced Aftertreatment for PM and NOx Control on Heavy-Duty Diesel Truck Emissions

Emissions from four heavy-duty and medium-duty diesel vehicles were tested in six different aftertreatment configurations using a chassis dynamometer. The aftertreatment included four different diesel particle filters (DPF) and two prototype selective catalytic reduction (SCR) devices for NO(x) control. The goal of the project was to fully characterize emissions from various in-use vehicles meeting the 2007 particulate matter (PM) standard for the United States and California and to provide a snapshot of emissions from 2010 compliant vehicles. The aftertreatment devices all worked as designed, realizing significant reductions of PM and NO(x). The DPF realized > 95% PM reductions irrespective of cycle and the SCRs > 75% NO(x) reductions during cruise and transient modes, but no NO(x) reductions during idle. Because of the large test matrix of vehicles and aftertreatment devices, we were able to characterize effects on additional emission species (CO, organics, and nucleation mode particles) from these devices as a function of their individual characteristics. The two predicting parameters were found to be exhaust temperature and available catalytic surface in the aftertreatment, which combine to create varying degrees of oxidizing conditions. The aftertreatments were not found to incur a fuel penalty.

Atmospheric Emissions from a Passenger Ferry with Selective Catalytic Reduction

The two main propulsion engines on Staten Island Ferry Alice Austen (Caterpillar 3516A, 1550 hp each) were fitted with selective catalytic reduction (SCR) aftertreatment technology to reduce emissions of oxides of nitrogen (NOx). After the installation of the SCR system, emissions from the ferry were characterized both pre- and post-aftertreatment. Prior research has shown that the ferry operates in four modes, namely idle, acceleration, cruise, and maneuvering modes. Emissions were measured for both engines (designated NY and SI) and for travel in both directions between Manhattan and Staten Island. The emissions characterization used an analyzer system, a data logger, and a filter-based particulate matter (PM) measurement system. The measurement of NOx, carbon monoxide (CO), and carbon dioxide (CO2) were based on federal reference methods. With the existing control strategy for the SCR urea injection, the SCR provided approximately 64% reduction of NOx for engine NY and 36% reduction for engine SI for a complete round trip with less than 6.5 parts per million by volume (ppmv) of ammonia slip during urea injection. Average reductions during the cruise mode were 75% for engine NY and 47% for engine SI, which was operating differently than engine NY. Reductions for the cruise mode during urea injection typically exceeded 94% from both engines, but urea was injected only when the catalyst temperature reached a 300 °C threshold pre- and postcatalyst. Data analysis showed a total NOx mass emission split with 80% produced during cruise, and the remaining 20% spread across idle, acceleration, and maneuvering. Examination of continuous NOx data showed that higher reductions of NOx could be achieved on both engines by initiating the urea injection at an earlier point (lower exhaust temperature) in the acceleration and cruise modes of operation. The oxidation catalyst reduced the CO production 94% for engine NY and 82% for engine SI, although the high CO levels during acceleration did cause analyzers to over-range. No clear, quantitative conclusions could be made regarding the effects of the SCR on PM

소형 무인 헬리콥터의 시스템 식별

In this paper, Recursive Least Squares (RLS) and Fourier Transform Regression (FTR) methods for estimating stability and control derivatives of small unmanned helicopter are evaluated together with MMLE technique. Flight data simulated by using a commercial small-scale helicopter model are exploited to estimate the parameters with accuracies for hover and cruise modes. The performances of the system identification methods are also compared by analyzing the responses of the reconstructed systems using estimated derivatives.

Low-Frequency Vibroisolation Mounting of Power Plants for New Generation Airplanes with Engines of Extra-High by-Pass Ratio

Compliance of aircraft with new noise standards defines the tendency to switch to extra-high bypass ratio engines. Substantial noise redistribution has occurred in the aircraft of the new generation. While jet noise has been reduced dramatically, the engine still remains the basic source of noise, which is a fan noise. In the forward hemisphere, beside the discrete components at fan blade frequency, long row of discrete components has been observed around the principal blade frequencies as result of shockwave influence. This phenomenon is called “buzz-saw noise”. Fan shaft frequency reduction is one of the necessary measures for shockwaves control. Due to the decrease of frequency, the vibration spectrum shifts towards the low-frequency range. Such components will determine dynamical impact spectrum of power plant, transmitted through mounting to the airframe construction. An airframe typically possesses dozens of oscillation modes in the low-frequency spectrum part. Interaction of some of them with the influence of power plant may generation of discrete low-frequency high-level noise components in cabin. We have designed a new low frequency attachment containing built-in elastic elements with non-linear characteristics and with quasi-zero stiffness zone at proof load by cruise mode.

Low-frequency vibroisolation mounting of power plants for new-generation airplanes with engines of extra-high bypass ratio

Compliance of aircraft with new noise standards defines the tendency to switch to extra-high bypass-ratio engines. Substantial noise redistribution has occurred in the aircraft of the new generation. While jet noise has been reduced dramatically, the engine still remains to be the basic source of noise, which is a fan noise. In the forward hemisphere, besides the discrete components at fan blade frequency, long row of discrete components has been observed around the principal blade frequencies as a result of shockwave influence. This phenomenon is called “buzz-saw noise”. Fan shaft frequency reduction is one of the necessary measures for shockwaves control. Due to the decrease of frequency, the vibration spectrum shifts towards the low-frequency range. Such components will determine the dynamical impact spectrum of power plant, transmitted through mounting to airframe construction. An airframe typically possesses dozens of oscillation the modes in the low-frequency spectrum part. Interaction of some of them with the influence of the power plant may generate discrete low-frequency high-level noise components in the cabin. We have designed new low-frequency attachments containing built-in elastic elements with nonlinear characteristics and with a quasi-zero stiffness zone at proof load by the cruise mode.

Modal Analysis of In-Use Emissions from Heavy-Duty Diesel Engines: On-Board Measurement

This paper reports the results of modal analysis performed to determine the episodic nature of events and emissions for engine operation within the not-to-exceed (NTE) zone, for each of the selected routes. West Virginia University developed a portable emissions measurement device called the mobile emissions measurement system to obtain engine operating conditions, vehicle speed, and in-use brake-specific emissions of CO2 and NOx from heavy-duty vehicles, tested on specific routes, which included a mix of highway and city driving patterns. The contribution of each mode to variations in emissions rates has been documented. The average brake-specific emissions of NOx and CO2 show a strong dependence on the driving modes and were the highest when the engine operated in the cruise mode. The amounts of time that the engine spends in the NTE region and also over continuous 30 s windows of NTE operation for the different routes were calculated. Results indicate that longer operation in the NTE region produced higher brake-specific emissions of NOx compared with their shorter operating counterparts. The primary implication of this work is that emission control strategies and policies should be focused on the mode of operation of the vehicle during on-road operation, in addition to existing procedures.

Estimation of Fish School Volume Using Omnidirectional Multi-Beam Sonar: Scanning Modes and Algorithms

Previous studies have resulted in a quantitative omnidirectional sonar (FSV30 research version, Furuno) using 64 multi-beams and a 24 kHz center operating frequency. The practical applications of this sonar are currently being studied with regard to fisheries resource assessment. This paper presents one part of this research, i.e., methods for estimating fish school volume using different sonar scanning modes. To determine its suitability for various purposes, we conducted a simulation to measure scatter aggregation; the simulation was validates by measuring the volume of a balloon filled with seawater. A practical survey was also simulated for spherical scatter aggregation with a 20 m diameter, and its volume was examined using different scanning modes. Our results indicate that a semicircular cruise mode is more suitable than a circular mode for measuring fish school volume, and that using an anchored instrument scanning mode provides greater accuracy than a cruising scanning mode.

비행 시험을 통한 비행선의 운동 특성 해석 및 시험 결과 분석

For decades, airships have being developed in Europe (especially German) and America. Airships are planning to be used for advertisements and airliners as well. In Korea, KARI (Korea Aerospace Research Institute) is developing stratospheric communication airship and the similar research is carried out in Japan. Among them, Zeppelin of German has the cutting-edge airship technology with Zeppelin NT. In this paper, the flight performance and stability were evaluated by comparing mathematical theory and the real test. The stability was examined through dynamic modeling and assured by designing controllers at each flight mode. Elevator angle, rudder angle, magnitude of thrust and tilting angle of thrust vector were used as control inputs. Moreover, after measuring the airship velocity, flight direction, magnitude and direction of the wind, attitude angles and trajectories of the airship at each flight mode, the results were compared with the simulation. To get the reasonable data, low-pass filter and band-stop filter were designed to get rid of the sensor noise and engine vibration. The test was accomplished at cruise mode, turning mode, and deceleration. To conclude, with comparing the simulation data and flight test data, it could be known that the dynamic model used in this paper was reasonable.

Diesel emissions prediction from dissimilar cycle scaling

A method for prediction of heavy heavy-duty diesel vehicle emissions on a test cycle using data from dissimilar test cycles is examined and presented. Four dissimilar modes of a new California test schedule were used to generate emission predictions for the US heavy-duty urban dynamometer driving schedule (UDDS). Intensive properties of each mode and of the UDDS, including average speed, stops/mile, percentage idle and average kinetic energy, were chosen for further study. The four dissimilar modes were the idle, creep, transient and cruise modes, created by the California Air Resources Board (CARB) in a prior effort. The predictive weightings were applied to emissions from 11 heavy-duty vehicles measured in units of grams/second (g/s), grams litre of fuel consumed (g/l) and brake specific emissions (g/kW h). Predictions of emissions for the UDDS in units of grams second of NOx and CO2were acceptable, but particulate matter (PM) deviations were substantial. Errors for prediction of NOx did not exceed 7 per cent for any case, and errors for CO2 prediction did not exceed 15 per cent. PM errors in the g/s case varied substantially, depending on the weighting case, indicating instabilities in the predictions. Errors for g/l and g/kW h predictions were higher. A series of corrections was applied to each of the predictive cases for each emissions unit studied. These corrections are shown to improve the predictive ability of the weightings, but the fundamental nature of the prediction was eroded. A weighting using the intensive properties of average speed, percentage idle and average kinetic energy was found to yield the best uncorrected prediction for every case, regardless of the emissions unit considered. The best predictive method was also shown to work acceptably when applied to unseen data from another 12 heavy-duty vehicles.

Quantification of Highway Vehicle Emissions Hot Spots Based upon On-Board Measurements

The purpose of this study is to demonstrate a methodology for quantification of high emissions hot spots along roadways based upon real-world, on-road vehicle emissions measurements. An emissions hot spot is defined as a fixed location along a corridor in which the peak emissions are statistically significantly greater by more than a factor of 2 than the average emissions for free-flow or near free-flow conditions on the corridor. A portable instrument was used to measure on-road tailpipe emissions of carbon monoxide, nitric oxide, hydrocarbons, and carbon dioxide on a second-by-second basis during actual driving. Measurements were made for seven vehicles deployed on two primary arterial corridors. The ratio of average emissions at hot spots to the average emissions observed during a trip was as high as 25 for carbon monoxide, 5 for nitric oxide, and 3 for hydrocarbons. The relationships between hot spots and explanatory variables were investigated using graphical and statistical methods. Average speed, average acceleration, standard deviation of speed, percent of time spent in cruise mode, minimum speed, maximum acceleration, and maximum power have statistically significant associations with vehicle emissions and influence emissions hot spots. For example, stop-and-go traffic conditions that result in sudden changes in speed, and traffic patterns with high accelerations, are shown to generate hot spots. The implications of this work for future model development and applications to environmental management are discussed.

Control of an underactuated remotely operated underwater vehicle

In this paper, a steady state model of a thruster and a general equation of rigid-body motion for an underwater robotic vehicle (URV) is presented. By means of modelling, simulation and experiments, the model parameters have been identified. These are used in the analysis and design of closed-loop stabilizing controllers for two control modes: manual cruise and station keeping. Since the URV under study has fewer actuators than possible degrees of freedom, it is necessary to limit the controllable degrees of freedom. These variables are eventually selected based on the inherent vehicle dynamics. Using the Lyapunov direct method, which has been shown to be appropriate for such non-linear systems, appropriate stabilizing controllers have been designed. The manual cruise mode controller is non-linear and would result in chattering in the thruster outputs, but simulations show that the desired results can be achieved. The station-keeping mode controller has a proportional-integral-derivative (PID) structure and its gain values are designed using a non-linear optimizing approach. Simulation and swimming pool tests for the heave and yaw directions have shown that such a controller is possible.

Control of an underactuated remotely operated underwater vehicle

In this paper, a steady state model of a thruster and a general equation of rigid-body motion for an underwater robotic vehicle (URV) is presented. By means of modelling, simulation and experiments, the model parameters have been identified. These are used in the analysis and design of closed-loop stabilizing controllers for two control modes: manual cruise and station keeping. Since the URV under study has fewer actuators than possible degrees of freedom, it is necessary to limit the controllable degrees of freedom. These variables are eventually selected based on the inherent vehicle dynamics. Using the Lyapunov direct method, which has been shown to be appropriate for such non-linear systems, appropriate stabilizing controllers have been designed. The manual cruise mode controller is non-linear and would result in chattering in the thruster outputs, but simulations show that the desired results can be achieved. The station-keeping mode controller has a proportional-integral-derivative (PID) structure and its gain values are designed using a non-linear optimizing approach. Simulation and swimming pool tests for the heave and yaw directions have shown that such a controller is possible.

Estimating Emissions and Fuel Consumption for Different Levels of Freeway Congestion

To improve upon the speed correction factor methodology used by conventional emission models (i.e., MOBILE and EMFAC), the Environmental Protection Agency is introducing in its latest version of MOBILE (version 6) a new set of facility-specific driving cycles. These cycles represent driving patterns for different facility types (e.g., highway and arterial) and congestion conditions. Using a state-of-the-art comprehensive modal emissions model developed under NCHRP Project 25-11, one is able to predict the integrated emissions and fuel use values for these cycles for a wide variety of vehicle-technology categories. These facility-congestion results are then compared with steady-state emissions-fuel use measurements that were made in deriving the modal model. Furthermore, cruise modes that have mild speed perturbations are also investigated. All of these results are then compared with the speed correction equations used in the conventional emissions factor models. It is found that the mild acceleration perturbations at high speeds can lead to significantly higher emissions compared with the steady-state values. Because of this, the new high-speed freeway driving cycles (representing higher levels of service) in many cases have (modeled) emissions higher than those for the cycles that represent lower levels of service. Fuel consumption by speed does not change drastically in the comparisons.

A novel concept for the next generation civil supersonic transport propulsion system: the retractable fan

Suggests that the next civil supersonic passenger aircraft project will pose a number of challenges. The propulsion system for this aircraft will have to achieve economic operation for both supersonic and subsonic cruise modes. In addition, the current and intended noise and pollutant emissions legislation will have to be met. Suggests that, while there are a number of proposed engines for the next generation civil supersonic aircraft, they all exhibit difficulties in meeting the compromises inherent in the engine duty. Offers a novel solution based on a unique design. Discusses the underlying issues and presents the design based on retractable fans driven by a single stage double pass tip turbine.

Study of aircraft cruise

The long range aircraft cruise problem is analyzed using a model intermediate in complexity between energy model and point mass model. It is shown that this formulation imbeds the classical steady state cruise as the central member along with several other oscillatory extremals. The oscillatory cruise trajectories are shown to exist if the Hessian of the function QD/VT with respect to altitude and airspeed is positive definite. An expression for predicting the frequency of oscillation is developed. Qualitative effects of increasing the vehicle thrust and improving the L/D are discussed. Numerical results for two fighter aircraft and a transport aircraft are given. While oscillatory cruise mode exists for the two fighter aircraft, steady state cruise at full throttle is found to be optimal for the transport aircraft. A second variation analysis to bring out the reason for fuel savings is developed. It is shown that whenever the Hessian of the function QD/VT is positive definite, the second variation will be zero along the classical steady state cruise arc, indicating that a neighboring extremal is competitive. Comparisons with the previous point mass and energy modeled results are given.

VENERA 13, 14 Unmanned Interplanetary Spacecraft Attitude Control Subsystem

Flight performances of the Venera 13, 14 spacecraft attitude control subsystem based on onboard telemetry data analysis are described. The spacecraft stabilization process in cruise mode is discussed. Design philosophy for attitude control subsystem development is also presented.

An ultrasonic head position interface for wheelchair control.

To give quadriplegics independent mobility, a "smart" microprocessor-based electric wheelchair has been developed by the Palo Alto Veterans Administration Medical Center and Stanford University. Ultrasound distance-ranging technology is employed to track the user's head position in two-dimensional space. These data are then used to determine the chair's direction and speed. A working prototype vehicle using this type of motion control has been successfully demonstrated. Obstacle detection, wall-following, and cruise control modes are other implemented features of the current design.

Advanced Digital Avionics of the DC‐9 Super 80

The DC‐9 Super 80 will be delivered with advanced avionics in early 1980. This paper discusses from the aircraft manufacturer's point of view the avionics system architecture, its digital implementation, and some hardware details of most major system elements. New operational features are discussed including Category IIIa autoland, some new autopilot and autothrottle cruise modes, a head‐up display system, and a “hot on‐board spare” flight guidance computer. Finally, some of the advantages of the digital system over analog systems are noted.

Attitude Control of Mariner Jupiter-Saturn Spacecraft

A major challenge of the Mariner Jupiter-Saturn '77 spacecraft was devising a suboptimal attitude controller that could meet the demanding mission requirements. The challenge was met by implementing a discrete stochastic controller for a specially designed onboard computer. The paper describes the design and operation of the controller, based on a simple model of spacecraft dynamics. Two types of cruising modes are considered: inertial cruise, where spacecraft attitude is determined from gyro position outputs, and celestial cruise, where position information is obtained from sun sensors and a star tracker. These two cruise modes under conditions of disturbances were simulated on computer, and the results showed that the controller maintained the spacecraft attitude with low rates. An appendix gives details on the single-step predictor.