Abstract: A method of creating a simplified computer implement for engine model comprises obtaining a complete computer implement for engine model (110) and selecting, from the complete engine model (110), elements defining the simplified engine model (110). The method further comprises obtaining from a library of rules at least one computer implementable model creation rule corresponding to the selected elements and using that at one rule to create the simplified computer implementable engine model (110).

Abstract: A method of controlling a rate of introduction of a NOx reducing substance or precursor to a catalyst component. The method comprises obtaining the amount of NOx entering the catalyst component, modelling the amount of NOx reducing substance or precursor in the catalyst component and controlling the rate of introduction of the NOx reducing substance or precursor to reduce NOx.

Abstract: A method and apparatus of identifying engine gas composition in an engine cylinder comprise obtaining a measure of cylinder pressure from a cylinder pressure sensor, deriving the polytropic index from said measure and obtaining a measure of the quantity of an engine gas component therefrom.

Abstract: A method of modelling the effect of a fault on the behaviour of a system. The method comprises modifying a functional model of a system to specify a fault in the system; running the model in accordance with a test, the test having an input and an expected output, the input defining the value of a least one input variable over a period of time and the expected output defining the expected value of at least one output variable over the period of time; the functional model calculating, in dependence on the value of the input variable defined by the input, a modelled output comprising the modelled value of the output variable over the period of time; and comparing the modelled output with the expected output to determine a severity score for the fault based on the difference between the modelled output and the expected output.

Abstract: A composite automotive pulley wheel and pump comprises a pulley wheel (2) and a pump (22). The pump comprises an impeller (20) carried on a rotary shaft (6), an inlet region (24) and an outlet region (26). The pulley is mounted on the shaft (6) and comprises a radially outwardly extending support (4) connected to an annular axially extending flange (10, 12), the outer surface of which is adapted to be engaged by a pulley belt. The flange (4) defines a cooling fluid passage (14) within it which extends in the circumferential direction and communicates at two circumferentially spaced positions with an inlet passage (16) and an outlet passage (18), respectively. The inlet and outlet passages (16, 18) extend through the support (4) and the shaft (6) and communicate with the outlet region (26) and the inlet region (24), respectively.

Abstract: A turbocharger system comprising first and second turbochargers, configured in series, where the turbochargers hand over control from one turbocharger to the other, which incorporates switching adjustment terms at the point of transition to ensure a smooth transition.

Abstract: A rotary shaft, such as an automotive crankshaft, for rotation about an axis carries an eccentric substantially circular section, radially extending flap (6), connected to the radially outer surface of which is an annular housing (16) affording a cavity defined in part by radially inner and radially outer coaxial cylindrical surfaces. The axis (22) of the cavity is offset from the axis (4) of the shaft. The cavity accommodates an annular inertia mass (20) and the radially inner and outer surfaces of the cavity are opposed to radially inner and outer surfaces, respectively, of the inertia mass whereby there are two pairs of opposed surfaces. One of the said pairs constitutes bearing surfaces guiding relative motion of the inertia mass and the housing (16) about the axis (22) of the coaxial cylindrical surfaces.

Abstract: A clutch including two rotary shafts, one of which is connected to one or more first clutch plates which cooperate with a second set of clutch plates, the clutch plates acted on by an actuating piston positioned within a two chamber hydraulic cylinder. A torque control valve comprising a cylindrical inner valve member rotatably and linearly movably received in a cylindrical opening in an outer valve member. Each valve member having elongate recesses positioned such that longitudinal movement of the inner valve member within the outer valve member will vary the degree of communication between the first and second elongate recesses connected to two hydraulic fluid sources of differing pressures. The second clutch plates are connected to one side of a spring of predetermined spring rate, which is also connected to one of the valve members, and the other side of the spring is connected to the other of the valve members and to the other rotary shaft.

Abstract: A vehicle control system includes at least one driver input, a supervisor and at least one sub-system controlled by the supervisor. The supervisor assesses the driver input to establish actual driver demand and controls the sub-systems accordingly. As a result intuitive driver demand is identified and met.

Abstract: An in-cylinder pressure sensor obtains a high resolution pressure curve for each cylinder cycle allowing the various data to be derived for improved monitoring and control of operation of the engine. A more accurate measure of work done by the engine is obtained allowing more accurate estimation of the vehicle torque and hence real torque control. In addition engine losses can be more accurately calculated and the estimates corrected yet further by obtaining an accurate top dead centre position for the engine cylinders.

Abstract: A carburettor for a two stroke engine includes a flow duct comprising rich and lean flow passages separated by a partition, at least one fuel jet communicating with the rich passage, the partition including an aperture towards which the fuel jet is directed, and a substantially planar butterfly valve being received in the aperture so as to be pivotable between a first position, in which the flow duct is substantially closed and the aperture is substantially open, and a second position, in which the flow duct is substantially open and the aperture is substantially closed, the flow duct further comprising a venturi section located substantially upstream of the aperture, and wherein the venturi section extends only partially around a perimeter of the flow duct.

Abstract: A method and apparatus for obtaining a corrected engine operational parameter value, using cylinder pressure information. A real pressure sensor signal output from a sensor (41D) is compared for discrepancies with an estimated output from engine pressure model (42A), including an engine model and a sensor model. The engine pressure model is corrected dependent on the discrepancy and the model engine pressure is then taken as the output value.

Abstract: A vehicle powertrain modelling system includes a powertrain model (20), a vehicle model (30), a seat model (55), a driver model (60) and a correlation element (50) comprising a neural network. As a result vehicle development is enhanced, using the neural network (50) to correlate modelled shift aspects with previous subjectively obtained ratings.

Abstract: The carburettor (1) includes a flow duct comprising rich (60) and lean (50) flow passages in parallel, through which, in use, air flows in a flow direction and which are separated by a substantially planar partition (30), at least one fuel jet 5 communicating with the rich passage (60), the partition (30) including an aperture (40) towards which the fuel jet (5) is directed, and a substantially planar butterfly valve (20) being received in the aperture (40) so as to be pivotable between a first position, in which the flow duct is substantially closed and the aperture (40) is substantially open, and a second position, in which the flow duct is substantially open and the aperture (40) is substantially closed, the upstream half of the aperture (40) being defined by an upstream semi-annular seating ledge (48) affording an upstream seating surface which is engaged by one of the surfaces of the butterfly valve (20) when it is in the second position and a first end surface which extends between the upstream seating

Abstract: A carburettor for a two stroke engine includes a flow duct including rich and lean flow passages (160, 150) in parallel, through which, in use, air flows in a flow direction and which are separated by substantially planar partition (130). At least one fuel jet (5) communicates with the rich passage (160) and the partition includes an aperture (140) towards which the fuel jet is directed. A substantially planar butterfly valve (120) is received in the aperture so as to be pivotable between a first position, in which the flow duct is substantially closed and the aperture is substantially open, and a second position, in which the flow duct is substantially open and the aperture is substantially closed.

Abstract: A control system for a load (10), the system comprising a first microprocessor (16) having an output to drive one side of a load (10), a second microprocessor (18) having an output to drive the other side of the load (10), the system being arranged so that when either microprocessor detects a fault in the control of the load (10) the load (10) is switched off.

Abstract: A vehicle powertrain modelling system includes a powertrain model (20), a vehicle model (30), a seat model (55), a driver model (60) and a correlation element (50) comprising a neural network. As a result vehicle development is enhanced, using the neural network (50) to correlate modelled shift aspects with previous subjectively obtained ratings.

Abstract: A method of generating a checksum for a data message comprises processing the data message to extract data blocks therefrom and computing a checksum from the data blocks. In particular non-linear operators are applied to the data blocks.

Abstract: A carburettor is connected into the inlet duct (48) of an internal combustion engine. The inlet duct is divided by a dividing wall (64) into a rich passage (42) and a lean passage (44). The carburettor includes a fuel chamber (4) and defines a flow duct divided by a planar partition (66) into a rich duct (30) and a lean duct (32) which communicate with the rich and lean passages, respectively. The partition (66) defines an aperture (40) in which a planar butterfly valve (20) is pivotably mounted. A number of fuel supply orifices (61, 62) communicate with the fuel chamber (4) and with the duct (30) at a position opposite to the aperture (40).

Abstract: A vehicle transmission system includes an input shaft connected to a differential mechanism, which has two output shafts. The two output shafts carry first and second coaxially mounted sun wheels, respectively, of an epicyclic gear system which mesh with first and second sets of planet wheels, respectively, which mesh with first and second annulus wheels, respectively. Each planet wheel is mounted to rotate independently about a respective planet shaft and the planet shafts are connected to a common carrier, which is rotatably mounted coaxially with the first and second sun wheels. The first and second annulus wheels are connected together. The carrier is connected to selectively operable speed changing device arranged to increase or decrease the speed of rotation of the carrier about its axis.