摘要:
An electronic microcomputer based engine brake control device and a method for controlling an engine compression brake is disclosed. An algorithm for enabling engine brake operation includes monitoring a brake enable switch, engine RPM, engine fueling rate, cruise control or power takeoff system activation state, throttle position, manifold pressure and clutch pedal position. Engine brake operation is fully automatic and operates in a safe manner according to the disclosed algorithm.
摘要:
A method is provided for computing a stabilized vehicle speed value from a detected vehicle speed pulse signal and a detected engine speed signal, the vehicle speed value being for use by a vehicle speed control system. The method comprises several continuous cyclic steps commncing with generating a measured vehicle speed value from the detected vehicle speed pulse signal and generating a measured engine speed value from the detected engine speed signal. A current gear ratio is calculated from the measured vehicle speed value and the measured engine speed value. This current gear ratio is then passed through a single pole digital filter to filter changes in the gear ratio between consecutive cycles as a function of the current gear ratio and the gear ratio computed in the last preceding cycle of the computation. A current usable gear ratio is generated which is changed from the most recently generated usable gear ratio only if changes in the gear ratio exceed predetermined limit values. Otherwise the current usable gear ratio is unchanged from its most recently generated value. A stabilized predicted vehicle speed value is then computed from the measured engine speed and the current usable gear ratio for use by the vehicle speed control system. Slew rate limiting of the predicted vehicle speed is also provided by the method.
摘要:
This invention provides a safety mechanism as an improvement to a bowstring release device and operative to prevent the accidental discharge of an arrow drawn in the bow. The safety mechanism disclosed comprises a slidable cam which is adapted to actuate a lock pin into a position to block the movement of a trigger member of the bowstring release device. When the safety mechanism is moved in the opposite direction, the lock pin is allowed to move away from the position blocking trigger movement under pressure of a biasing spring, thus freeing the trigger to operate.
摘要:
A feedforward disturbance compensation system and method for use with a spacecraft that compensates for predictable disturbances exerted on the spacecraft. The invention comprises a model of the disturbance that is to be compensated, means for knowing when the disturbance will occur, and means for applying the feedforward compensation to the spacecraft in accordance with the model (a compensation profile). The present invention reduces pointing transients through the application of open-loop, feedforward compensation of actuators used to point the spacecraft. The shape of the feedforward profile is determined by an in-orbit test or is predicted by analytical means. For the in-orbit test case that compensates for an eclipse, for example, the spacecraft is flown through the eclipse once to determine the size and shape of the thermal shock disturbance and this information is stored in a spacecraft control processor. The application of the feedforward compensation is synchronized with the start and end of each day's eclipse. This may be achieved by sensing the change in battery discharge current that occurs in solar panels on the spacecraft, for example. On subsequent days, the invention anticipates the occurrence of the disturbance using the stored data. When the start or end of eclipse is detected, compensation for the expected disturbance is automatically applied to spacecraft actuators. The invention can also compensate for a large variety of known periodic disturbances other than thermal shock. These disturbances may be external or internal to the spacecraft. The present invention can also provide compensation by fine tuning the compensation magnitude and duration of the compensation, and is also applicable to both linear and nonlinear control systems.
摘要:
Method and apparatus for reducing torpedo drag in which polymer drag redug material is carried by the torpedo in concentrated form, ambient water is ingested and mixed with the concentrated polymer to produce a seawater-polymer solution of predetermined concentration, and the solution is ejected from the torpedo nose to be swept rearwardly in intimate contact with the exterior surface of the torpedo under torpedo forward motion.
摘要:
A method of spacecraft attitude determination is proposed which calculates the bias between the usual two-cell and four-cell earth sensor measurements. During period of sun or moon interference, when the two-cell mode is selected, this bias is added to or subtracted from the two-cell measurements. This removes the step change in the calculated spacecraft roll and pitch angles when the switch is made between two and four cell modes and allows a substantially more accurate measurement to be obtained from a given sensor for the period of time for which interference would otherwise reduce sensor performance.
摘要:
Structures and methods are provided for deriving corrected star coordinates Ccrctd from measured star coordinates Cms that include star tracker charge transfer efficiency (CTE) errors. The structures and methods are based on a recognition that measured star coordinates Cms of star image centroids include CTE errors which are functions of the CCD path lengths over which the associated electrical charges traveled. In particular, the errors are substantially a product of a respective path length and a star-coordinate error factor &xgr; which, in turn, is a function of the star image magnitudes msi. Information contained in different measured star coordinates Cms is organized to facilitate the derivation of an estimate &xgr;* of the star-coordinate error factor &xgr; with conventional estimation processes. The measured star coordinates Cms are then corrected with the error factor estimate &xgr;* to realize the corrected star coordinates Ccrctd and, thereby, improve the accuracy of spacecraft attitude control.
摘要:
1. Apparatus for inflicting explosive damage upon an underwater object, crising;(a) an encapsulated charge of a first material which is highly reactive with water, said first charge being for explosively reacting with the water to produce a gas bubble which sequentially expands to a predetermined peak size and then contracts,(b) explosive means for bursting the encapsulated charge in a manner in which the bursted particles of said first materials are dispersed in directions symmetrically outward from the center of the charge to cause the bursted particles of said bursted material to penetrate the ambient water with a symmetric and uniformly dense pattern of penetration, and thereby obtain effective and complete explosive reaction between said first material and the water medium and produce said peak size of bubble, and(c) means for initiating said explosive means for bursting the encapsulated charge when said charge is sufficiently close to the object that a material portion of the bubble front is in contact with the surface of the object when the bubble reaches its peak size,whereby upon contraction of the gas bubble a re-entrant jet of ambient water enters the bubble in a direction normal to the surface of the object to exert a punch-like force thereagainst.