Showing papers on "Range (aeronautics) published in 1985"

Periodic optical cruise of an atmospheric vehicle

Abstract: Since the steady-state cruise path of an idealized point mass model of an atmospheric vehicle operating in the hypersonic flight regime is dynamically not fuel minimizing, closed periodic paths are numerically determined. By application of second-order conditions for local optimality, a periodic extremal path for a flat Earth is shown to be locally minimizing and produces an improvement in fuel usage of 4.2% over the steady-state cruise path. Application of these second variational conditions to extremal paths for the spherical Earth failed. Nevertheless, these paths produce improved fuel performance over the associated steady-state cruise path. UEL efficient cruise trajectories for aircraft have been a subject of continuous theoretical interest and are becoming one of practical interest as well. The analysis of aircraft trajectories for fuel minimization was first performed in a reduced state space.1"3 By neglecting the altitude and flight path angle dynamics, the equations of motion of a point mass representation of the aircraft motion reduces to the energy-state approximation where energy and fuel mass are the state variables, thrust and velocity (or altitude) are considered the control variables, and range is the independent variable. The first-order dynamics or rates are represented by the rate of change in the energy and fuel with respect to a change in range. The hodograph3 is formed by determining the boundary of reachable rates for admisible values of the control variables at a given energy value (the rates are independent of the fuel). The steady-state cruise fuel performance is given by the value of the fuel mass rate where the hodograph crosses the zero energy rate axis. If the hodograph is not convex so that a straight line tangent to two points on the hodograph (called the convex hull3) crosses the zero energy rate axis at a smaller value of fuel mass rate than does the hodograph, then the control variables at the points of tangency are used to form a chattering control sequence which theoretically will improve fuel performance over the steadystate cruise path. This chattering sequence, first discussed in Ref. 1, is an unrealizable infinite frequency control sequence between two thrust levels and two altitude and velocity points on the energy manifold where the aircraft is aerodynamic or propulsion efficient. This chattering cruise is also referred to as the relaxed steady state cruise in Ref. 2. Since velocity and altitude chattering is unrealizable, altitude has been added as a state variable in Ref. 4 and thrust and flight path angle are considered the control variables. In Ref. 4 the small angle approximation applied to the flight path angle results in flight path angle and thrust appearing linearly in the aircraft dynamic model and cost function. These control variables which lie interior to their admissible control sets along the extremizing steady-state cruise path form what is called a doubly singular arc in the calculus of variations.5'6 By applications of the matrix generalized Legendre-Clebsch condition due to Robbins, 7 it is demonstrated in Ref. 8 that the steady-state cruise path is not minimizing..

Indicating system for warning airspace or threatening aircraft in aircraft collision avoidance system

Abstract: The present invention relates to a indicating system for warning airspace or threatening aircraft in aircraft collision avoidance system which provides simply and inexpensively information required for safe cruising of aircraft with respect to range of warning airspace of aircraft, positions of other aircraft involving threatening of collision, and flight courses of proximate said other aircraft involving threatening of collision. The present system can provide simply and inexpensively information indispensable for safe cruising of aircraft with respect to range of warning airspace of aircraft, positions of other aircraft involving threatening of collision, and flight courses of proximate said other aircraft involving threatening of collision by such manner that the warning airspace is changed into a required shape in response to speed of a subject aircraft, and indication range for the threatening aircraft is changed in response to angle of climb or descent of the subject aircraft, besides detected data of distances and bearings with respect to the other aircraft are indicated by a prescribed afterglow time.

X-wing helicopter-scout attack configuration

Abstract: The present invention provides a single seat aircraft having the capabilities of vertical takeoff, landing and hovering operations utilizing the X-Wing as a conventional helicopter rotating wing. After transition to forward flight following takeoff, the rotating wing is stopped and becomes a fixed wing of "X" configuration. The aircraft utilizes two engines within the fuselage, one engine being positioned vertically above the other along the longitudinal axis of the aircraft, the particular arrangement of engines allowing aircraft size and weight to be substantially reduced.

New Concepts in Control Theory, 1959-1984

Abstract: ONTROL theory is a branch of applied mathematics that deals with the analysis and synthesis of logic for the control of man-made systems. It is applied to a wide range of fields from aerospace to robotics and economics. Its applications to aerospace can be divided into four areas: 1) Flight Planning: The determination of a nominal flight path and associated control histories for a given vehicle to accomplish specified objectives with specified constraints. 2) Navigation: The determination of a strategy for estimating the position of ^vehicle along the flight path given outputs from specified sensors. 3) Guidance: The determination of a strategy for following the nominal flight path in the presence of off-nominal conditions, wind disturbances, and navigation uncertainties. 4) Control: The determination of a strategy for maintaining angular orientation of the vehicle during the flight that is consistent with the guidance strategy and the vehicle, crew and passenger constraints. These four categories often overlap. For example, aircraft velocity and angular orientation are coupled, so that guidance and control of aircraft must be considered together. Dynamic Models A prerequisite for developing a satisfactory control history or strategy is a satisfactory dynamic model of the system to be controlled (often called the-"plant" by controlengineers). Dynamic modeling of aircraft began with Bryan's work in the early 1900's (see Refs. 1 and 2 for excellent descriptions of the history). When computers became reliable and economical in the 1950's, interest in dynamic modeling for simulation and control design increased considerably. References 2, 3, and 4 cover the state of the art in dynamic modeling of aircraft. Dynamic modeling of spacecraft began in the 1960's and now includes elastic modeling of spacecraft with many connected components. References 4 through 9 cover much of the state of the art in dynamic modeling of spacecraft, boosters, and missiles. Dynamic models can be inferred from tests run on the plant. A pilot flying a new aircraft develops a "model" of the aircraft in his brain based on his perceptions of its responses ("outputs") to his motions of the controls ("inputs"). In the last ten to twenty years, investigators have learned how to emulate the pilot by constructing dynamic models of an aircraft from recorded input and output histories (see "Identification" to follow). These models are then stored in a computer for later use in synthesizing autopilot logic.

Aviation Fuels Technology

Abstract: This book presents the current specifications for aviation gasolines and turbine fuels, with descriptions of the method of test for each property, and of the main production processes to achieve the specified standards. The possibilities of supplemental fuels derived from alternative sources are discussed. The availability, properties and performance of a range of substitute fuels, together with the energy economy of the production and use of these alternatives are also examined. Topics covered include: current aero engine types; current aviation fuel types; production; specification test methods; operational handling; fuel characteristics within air-craft fuel systems; fuel combustion performance; development of specifications; relaxation of specifications; aviation fuels from alternative sources; aviation fuels substitutes; and fuels for high performance aircraft.

Stratiform charging engine

Abstract: PURPOSE:To obtain excellent combustibility and improve exhaust gas purifying performance by performing at a light load, a stratiform combustion by the supply of unevenly distributed fuel to the vicinity of the ignition device, at a heavy load range, uniform combustion by the supply of dispersed fuel, and in a deceleration operation by throttling the suction air. CONSTITUTION:In a combustion chamber 1, a sparking plug 8 and a stratifying fuel injection nozzle 9 which supplies fuel to the vicinity of the sparking plug 8 are provided. On the other hand, in a suction passage 3, a dispersing fuel injection nozzle 12 which supplies dispersed fuel and a throttle valve 14 which is opened or closed by an actuator 15 are arranged. When the load is in the range of light or medium below a set value, the supply of the dispersed fuel is stopped and stratified fuel is supplied for stratiform combustion, and when the load exceeds the set value the stratified fuel is decreased and dispersed fuel is increased to proceed to uniform combustion. In a deceleration operation, the throttle valve 14 is closed, which reduces the suction air quantity, decreases the quantity of air flowing through a catalyzer device 7, and prevents the device 7 from being excessively cooled, thus improving the exhaust gas purifying performance.

Orbit on demand - In this century if pushed

Abstract: Performance requirements and design features of the next generation of manned launch vehicles are discussed. The vehicles will launch within minutes of demand and will have a several-day turnaround time. Launch and landing sites will have minimal facilities. Baseline requirements comprise carriage and return of a 5000 lb, 7 ft diam, 15 ft long payload, a 160 n. mi. polar orbit, a 200 fps on-orbit delt-V capability, provisions for two men for 24 hr, an 1100 n. mi. cross range option, 500 flights/vehicle, land on 10,000 ft runways, and be acceptable passing over populated areas. Significant advances are needed in propulsion and fuel systems, lightweight durable structures and airbreathing acceleration engines. Trade-offs have yet to be fully explored among the number of stages and horizontal or vertical take-off.

Method for indicating a vehicle operation in a fuel economy range for a vehicle with a manual transmission

Abstract: A method for indicating a vehicle operation in a fuel economy range, for a vehicle with a manual transmission, indicates that the vehicle is operating in a fuel economy range when both of an up-shifting condition and a down-shifting condition are not satisfied. The method further detects a non-regular state of the vehicle operation and stops the indication of the vehicle operation under the fuel economy range when the non-regular state of the vehicle operation is detected even though both of the up-shifting and down-shifting conditions are not satisfied.

Speed control system for vehicles

Abstract: In a speed control system for a vehicle, when a desired running speed of the vehicle is to be preset, the desired running speed of the vehicle is compared with the actual running speed so that when the resulting difference between the desired running speed and the actual running speed exceeds a predetermined range, the operation of presetting the desired running speed is limited.

Method for optimizing the air/fuel ratio under non-steady conditions in an internal combustion engine

Abstract: A self-optimizing control method for optimizing the fuel/air ratio under non-steady conditions in an internal combustion engine is described; in this method, a probe is provided both before and after the catalyst Control quantities and the time during which the post catalyst probe shows an undesirable fuel/air ratio are stored for certain specified engine-operating conditions in the non-steady range When the same engine operating condition is repeated, reference is made to the stored control quantities and time and the control quantity is varied in the direction of the correct fuel/air ratio The time now obtained is compared with the stored time and, if the time has decreased, the new control quantity and the new time are stored The control values are iteratively corrected by repeating these procedures, when the same engine operating condition reappears, until the time reaches a minimum

Automatic speed change gear

Abstract: PURPOSE:To prevent a motor car from starting suddenly, by a method wherein power transmission is made to perform after an engine speed has been reduced when shifting operation of a shift lever from a stopping range to a running range is made in case where an accelerator pedal is being stepped in during suspension of a vehicle. CONSTITUTION:In case of putting the title device into operation on a diesel engine, when an accelerator pedal 26 is stepped in and a shifting operation of a shift lever 34 is done from a suspension range to a running range when a matter that a vehicle is being suspended is detected by an output of a car speed sensor 35, a fuel injection quantity control component (spill ring) is shifted to an idling position by an electronic controller 12, in an injection pump 10. An injection quantity, therefore, of fuel from a fuel injection valve 6 is reduced and an engine speed is reduced to an idling speed. With this construction, a clutch 40 is shifted from a disengaged state to an engaged state, output torque of the engine is transmitted to a driving shaft through an automatic speed change gear 38 and then the vehicle is started.

Investigations into the effects of scale and compressibility on lift and drag in the RAE 5m pressurised low-speed wind tunnel

Abstract: : A survey is presented of results obtained from experiments in the RAE 5m low-speed pressurised wind tunnel. The tunnel is capable of operation over a range of pressures (from one to three atmospheres) so that the effects of Mach and Reynolds number may be separated. This decoupling of scale and compressibility effects has made possible reliable extrapolation of test results to full-scale conditions (where this is necessary) as well as giving greater insight into the underlying flow mechanisms. The large size of the tunnel, combined with pressurisation to three atmospheres, has enabled some tests, on small combat/trainer aircraft and on bomb-like stores, to be carried out at full scale. Three facets of the work of the 5m tunnel are described: work aimed at predicting or improving the high-lift performance of specific aircraft; work of a more fundamental nature concerned particularly with the optimisation of high-lift devices on generalised research models, and work on the drag of stores carried externally on combat aircraft. (Author)

Aircraft flight command and windshear-display system

Abstract: A system particularly adapted for guiding aircraft through wind shear conditions includes: a thrust com­mand control (10) for maintaining airspeed and ground­speed within a defined range; a detection system (12) for detecting and annunciating the presence of moderate and severe wind shear; and a pitch command system (14) which provides pitch command signals for optimum climb out from a wind shear condition.

The Future of International Air Transport

Abstract: Australia is one of the world's most advanced nations in terms of international air transport. Air travellers to and from Australia enjoy access to technology which has made the modern jet aircraft the safest, fastest, most efficient, reliable and economic means of transport in the world today. Australia's own international carrier, Qantas, is at the leading edge of the continuing dynamic process of applying new, appropriate technology in order to maintain reliable, economic and low-cost service for the travelling public. The company's current billion-dollar fleet modernisation programme, being funded entirely from the airline's own resources, embodies substantial innovation, including: - pioneering application of the advanced version of the Rolls Royce RB 211 524D4 engine, the power plant for Qantas' four new Boeing 747-300 Extended Upper Deck aircraft, offering more power and reduced fuel consumption; - pioneering use in the Asia-Pacific region of the extended range version of the Boeing 767, allowing non-stop, full-payload service on developing long haul routes such as Perth-Tokyo, and more frequent service on low-density routes; - new cockpit philosophies, incorporating advanced avionics which reduce the number of flight crew from three to two. - use of new lightweight materials to reduce aircraft weight and so enhance payload range capability.

Further work on modelling car fuel consumption

Abstract: Four fuel consumption models are described which cover the range of applications in urban traffic management. The models are all interrelated and keep the same set of vehicle characteristics as explicit parameters. An extension to the power (energy) model of car fuel consumption is described which considerably improves the model's accuracy, especially during hard accelerations. Drag power is estimated using steady speed fuel consumption data to ensure that the three components, rolling, engine and aerodynamic drag are all included. Functions for estimating acceleration, cruise and deceleration fuel consumption are developed by integration of the extended power model. These are used to form a four mode elemental model of fuel consumption which is very flexible in both its range of applications and data requirements. A model similar to the pke model called the running speed model is developed from the cruise fuel consumption function. The average travel speed model is related to this model and a method is given for modifying the parameters to suit different vehicles. The accuracies of the four models are described. The results of further work on the polynomial model of acceleration profiles are also given, and the dependence of fuel consumption on acceleration rate and profile is discussed (a).

Travel control unit for vehicle

Abstract: PURPOSE: To aim at reducing the fuel consumption of a vehicle and at improving the drive feeling thereof, by providing such an arrangement that the difference between an upper limit and a lower limit which are set by an upper and lower vehicle speed limit setting means increases as set speed increases. CONSTITUTION: The supply amount of fuel for an engine 20 is controlled to effect a moderate acceleration until the speed of a vehicle increases from a lower limit to an upper limit which are set within a constant speed travel range by a computer 30 with reference to a set vehicle speed unit 2, and therefore, when the vehicle sped reaches the upper limit, a clutch 10 is energized to cut off the transmission of drive power to wheels so that inertial travel is carried out until the vehicle speed decreases to the lower limit. In this case, setting is made such that the difference between the upper and lower limits increases as the set vehicle speed speed increases. Accordingly, by repeating moderate acceleration and inertial travel, it is possible to realize travel at a constant low speed with low fuel consumption, and further it is possible to reduce affection upon drive feeling, which is accompanied by vehicle speed changes during travel at a low speed. COPYRIGHT: (C)1987,JPO&Japio

Air/fuel mixture ratio learning controller in electronic control fuel injection internal combustion engine

Abstract: To control the air/fuel mixture ratio of an internal combustion engine, a pulse duty signal Tp corresponding to the amount of fuel to be injected is calculated at least from the intake air flow rate Q and the engine rotation speed N, a suitable correction value is applied to Tp to correct the amount of fuel to be injected Ti, and a signal representing the amount of fuel to be injected Ti is applied to a pulse control fuel injection unit. A correction is fed back to change the detected air/fuel ratio to the desired air/fuel ratio. A learned correction coefficient alpha0 is calculated to reduce the correction coefficient to a value as small as possible, and applied as a correction value to the Tp. However, since the reliability of alpha0 is small in the operating range where learning does not occur, an assumed value of alpha0 in that range is interpolated based on the value of alpha0 in the range in which learning occurred, thereby smoothening the gradient of control of the transient air/fuel ratio between different ranges.

Fuel injection device of engine

Abstract: PURPOSE:To pulverize fuel and as well to sufficiently attain the mixing of fuel and air, by arranging a first fuel injection valve for carrying out fuel injection ranging from the low load range to the high load range in the vicinity of a combustion chamber, and as well by arranging a second fuel injection valve for the high load range, apart from the combustion chamber. CONSTITUTION:A primary fuel injection valve 16 for carrying out fuel injection ranging from the low load range to the high load range is disposed in a primary branch intake-air passage 7 connected to a primary air port 4, proximate to a combustion chamber 2. Further, a second fuel injection valve 17 for carrying out fuel injection upon high speed and high load operation, is disposed in a secondary branch intake-air passage 9 connected to a second intake-air port 5, farther away from the combustion chamber 2 than the primary fuel injection valve 16. With this arrangement, the pulverization of fuel and the mixing of fuel and air may be sufficiently attained even in the high speed and high load operating range in which the time restriction for pulverization and evaporation of fuel is severe. Further, the increment of fuel for acceleration is injected from the primary fuel injection valve 16 proximate to the combustion chamber 2, thereby the responsiveness upon acceleration may be enhanced.

The Altitude Wind Tunnel (AWT) - A unique facility for propulsion system and adverse weather testing

Abstract: A need has arisen for a new wind tunnel facility with unique capabilities for testing propulsion systems and for conducting research in adverse weather conditions. New propulsion system concepts, new aircraft configurations with an unprecedented degree of propulsion system/aircraft integration, and requirements for aircraft operation in adverse weather dictate the need for a new test facility. Required capabilities include simulation of both altitude pressure and temperature, large size, full subsonic speed range, propulsion system operation, and weather simulation (i.e., icing, heavy rain). A cost effective rehabilitation of the NASA Lewis Research Center's Altitude Wind Tunnel (AWT) will provide a facility with all these capabilities.

Ground-simulation investigation of VTOL airworthiness criteria for terminal area operations

Abstract: A two-part ground simulation investigation of variables that affect VTOL terminal area operations was conducted. The baseline vehicle selected was a generalized tilt-rotor aircraft. Experimental variables included the manner in which conversion from airborne to thrust-borne flight is effected, the coupling between conversion and aircraft pitch and heave control, and the allowable range of airspeeds at given thrust inclination angles. Four pilots conducted over 200 piloted evaluations of combinations of these variables for representative VTOL terminal area tasks. Among the results shown are that, for visual approaches, the conversion profile had minimal influence on the aircraft's acceptability but, for instrument approaches, desired performance could be achieved only if all of the conversion was performed prior to acquiring the glide slope, or if additional automation and display assistance was provided.

Preliminary sizing and performance of aircraft

Abstract: The basic processes of a program that performs sizing operations on a baseline aircraft and determines their subsequent effects on aerodynamics, propulsion, weights, and mission performance are described. Input requirements are defined and output listings explained. Results obtained by applying the method to several types of aircraft are discussed.

Idle controller of engine

Abstract: PURPOSE:To quickly concentrate an idling speed to a desired speed when an external load is activated, by performing control of the idling speed with an air fuel ratio fixed to a point of rich mixture during the recovery period to the desired revolution speed when the external load is activated CONSTITUTION:When idling speed control is shifted to feedback control, a desired revolution speed is set according to an engine temperature and a load switch to extract a difference RPM between the desired revolution speed and an actual revolution speed When an external load is activated, anticipated compensation of the quantity of air sucked is performed and it is discriminated whether the difference DELTARPM of a revolution number is within a safety range indicated by +-beta or not If the difference is out of the safety range the air fuel ratio is fixed to the rich level and feedback control of the air fuel ratio is interrupted As aforementioned, the feedback control of air fuel ratio is interrupted with air fuel mixture rich in case the difference between revolution numbers is great, the air fuel ratio is restrained from getting lean in company with an anticipated increase of intake air when an external load is thrown and temporary drop in revolution number due to lack of output may be prevented

2-cycle internal-combustion engine

Abstract: PURPOSE:To improve fuel consumption and exhaust gas and to eliminate uncomfortable vibration by obtaining stable combustion of every other rotation or every some rotation by supplying fuel to an engine once in 2 cycles or some cycles in low negative load time. CONSTITUTION:In low load combustion cycle, a piston 4 is dropped to inject fuel into a cylinder 1 from a fuel injection valve 16 while a scavenging port 17 is opened. In the next cycle, fuel supply is completely stopped and scavenging cycle by air is produced. Thus, the inert gas ratio is reduced to perform sure combustion once in two cycles. In a normal running range, combustion of every cycle is possible.

Travel control device for vehicle

Abstract: PURPOSE: To hold an average speed of actual speed at a set vehicle speed with a high degree of accuracy, by providing such an arrangement that the difference between an upper limit which is set by an upper and lower vehicle speed limit setting means and the set vehicle speed is greater than that between the set vehicle speed and a lower limit. CONSTITUTION: The supply amount of fuel for an engine 20 is controlled to effect a moderate acceleration until the speed of a vehicle increases from a lower limit to an upper limit which are set within a constant speed travel range by a computer 30 with reference to a set vehicle speed unit 2, and therefore, when the vehicle speed reaches the upper limit, a clutch 10 is energized to cut off the transmission of drive power to wheels so that inertial travel is carried out until the vehicle speed decreases to the lower limit. In this case, setting is made such that the difference between the upper limit and the set vehicle speed is greater than that between the set vehicle speed and the lower limit. With this arrangement, control may be made such that an averaged vehicle speed during travel at a constant speed approaches the set speed, thereby it is possible to realize travel control with a high degree of accuracy. COPYRIGHT: (C)1987,JPO&Japio

Method of controlling air fuel ratio of engine

Abstract: PURPOSE:To improve fuel consumption with an engine rpm. ensured stably without any possibility of reducing operating characteristics of an engine by detecting the instability degree of the engine under constant operating condition and gradually reducing the air fuel ratio if the degree exceeds the value preset for preventing misfire. CONSTITUTION:A controller 14 constituted by a microcomputer calculates the standard fuel injection period of an injection valve 7 from the relation between the quantity Q of intake air detected by an air flow meter 2 and the rotational speed N detected by a rotational angle sensor 20. The controller makes both compensation of the injection period by the signals from a water temperature sensor 16, a throttle sensor 4 and so on and theoretical air fuel ratio control by the signal from an O2 sensor 13. Additionally, by varying the quantity of air from a bypass air solenoid valve 6, the controller determines whether the air/fuel ratio for optimum fuel consumption is in either rich range or lean range and compensates the air fuel ratio for lean mixture with an engine in constant operation. At the time of the constant operation, the controller detects instability degree of the engine from the difference between the maximum and minimum rotational speeds exhibited during every cycle of successive 120 deg.-cranking motions. If the degree exceeds the value preset to prevent misfire, the controller reduces the air fuel ratio gradually to prevent reduction of operating characteristics.

Knock preventing method for engine utilizing two kinds of fuel

Abstract: PURPOSE: To prevent knock over the whole operating range, by sucking the mixture of gasoline and air, and by injecting light oil into a combustion chamber in the vicinity of the top dead center during compression stroke. CONSTITUTION: During suction stroke of a high compression ratio engine 1, gasoline from a fuel supply device in an intake-air pipe 3 is atomized and then fed, and the thus obtained mixture is charged into a combustion chamber, and then light oil is injected into the combustion chamber in the vicinity of the top dead center during compression stroke to autogenously ignite the mixture and oil. Further, by adjusting the supply ratio between gasoline and light oil in accordance with the operating condition of the engine, it is possible prevent knock in low, middle and high load ranges. COPYRIGHT: (C)1987,JPO&Japio

Large-scale Advanced Propfan (LAP) performance, acoustic and weight estimation, January, 1984

Abstract: In comparison to turbo-prop applications, the Prop-Fan is designed to operate in a significantly higher range of aircraft flight speeds. Two concerns arise regarding operation at very high speeds: aerodynamic performance and noise generation. This data package covers both topics over a broad range of operating conditions for the eight (8) bladed SR-7L Prop-Fan. Operating conditions covered are: Flight Mach Number 0 - 0.85; blade tip speed 600-800 ft/sec; and cruise power loading 20-40 SHP/D2. Prop-Fan weight and weight scaling estimates are also included.

In-Use Vehicle Survey of Fuel Consumption and Emissions on Dynamometer and Road

Abstract: An upgraded vehicle fuel consumption/emission test facility is shown to be able to simulate on-road performance of cars up to wide open throttle operation. A procedure is described which permits dynamometer loads to be set so as to replicate the on-road, steady speed fuel consumption of each vehicle tested. A test program involving five driving cycles (schedules), three US and two Australian, and a range of other manoeuvres has been devised, to describe a wide range of on-road driving. The tests last one week and have been carried out on a fleet of almost 40 cars. Fuel and emission data has been logged at every half second interval of the tests. The overall test results only have been reported here. It is shown that there is considerable variability in the response of individual cars to changed test cycle. For the Australian test cycle fuel consumption is typically 15% higher than to US 75 FTP city test schedule. Corresponding increases in emissions are nearly 50% for HC, 90% for CO and 30% for NOx. There is some evidence that vehicle designs are "tailored" to the emission test cycle, and thus perform less well in more normal driving. There are indications that non-weight related improvements in recent model cars are more effective in reducing "on-road" fuel consumption than reflected by the US city test schedule. Lastly the influence of ambient temperature on fuel consumption and emissions is shown to be significant.

Fuel control device in engine

Abstract: PURPOSE:To optimumly control the air-fuel ratio over a wide operating range, by controlling either one of or both of the opening degree of the throttle valve and the fuel injection amount so that the actual fuel ratio takes a desired value, individually having the dynamic characteristic models of the fuel and air system. CONSTITUTION:Upon engine operation, a computing circuit 11 determines in which range B1, B2, B3 the running condition of the engine falls, in accordance with the rotational speed and load of the engine at that time. In the transition range B2 the injection amount of fuel and the opening degree of the throttle valve are calculated in view of the depressed amount of an accelerator pedal 9, etc., and therefore, a fuel injection valve drive circuit 12 and a throttle valve drive circuit 15 are controlled. Meanwhile, in the range B3, after the supply amount of fuel to an engine cylinder is calculated in view of the injection amount of fuel and the dynamic characteristic models of the fuel system, the fuel preference type control is made to determine the opening degree of the throttle valve in view of the amount of intake-air determined to allow the air- fuel ratio to take a desired value, and in view of the dynamic characteristic model of the air system. Further, in the range B2 the supply amount of fuel is determined by the air preference type control.

Device for controlling the fuel injection quantity in an internal combustion engine

Abstract: A fuel injection pump serves for injecting fuel into an engine. A movable element determines the quantity of fuel injected into the engine. The fuel injection quantity is a function of the position of the movable element. A critical position of the movable element is defined as one which lies between a range in which fuel injection is possible, and another range in which no fuel is injected. The movable element is controlled on the basis of the measured engine operating state and the measured critical position.