Patent Application
20070294015
The present invention relates to a power train control method and system.
The present invention may be used to advantage in a power train comprising an internal combustion engine, to which the following description refers purely by way of example.
The control system of a power train comprising an internal combustion engine comprises at least one electronic control unit (ECU) located close to the engine and normally housed in the engine compartment of a vehicle; and a number of sensors connected to the control unit to measure various power train operating parameters (e.g. drive shaft angular position and rotation speed) which are used by the control unit to control the power train.
Optimum control of power train performance by the control system calls for measuring various power train parameters which are extremely complicated and expensive to measure (such as the rotation speed of a turbosupercharger). In other words, certain power train parameters (such as turbosupercharger rotation speed) can only be measured accurately using either laboratory instruments (which are extremely accurate but obviously unfeasible in a mass production context, for reasons of cost, size, and dependability) or invasive, extremely high-cost, potentially unreliable sensors.
US2001023685A1 discloses an air-fuel mixture control device controlling a combustible air-fuel mixture to be supplied to a combustion chamber of an engine; this device is constructed of an injector used for fuel supply, a fuel pump, a fuel filter, a fuel pressure regulator, and an electronic control unit, which are united as an assembly with respect to a throttle body including an intake passage and a throttle valve. A memory incorporated in the ECU stores a correction value with respect to the fuel injection quantity dispersion preliminarily experimentally determined on an assembly-by-assembly basis; the ECU corrects the fuel injection quantity based on the correction value stored in the memory to control the fuel injection quantity.
It is an object of the present invention to provide a power train control method and system designed to eliminate the aforementioned drawbacks, and which are straightforward and cheap to implement.
According to the present invention, there are provided a power train control method and system as claimed in the attached Claims.
A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
Number 1 in
Power train 1 comprises an internal combustion engine 2 with four cylinders 3 (only one shown in
Intake manifold 4 is supplied with fresh air (i.e. air from outside) via a throttle valve 10 adjustable between a closed position and a fully-open position. An exhaust device 11 with one or more catalysts (not shown in detail) extends from exhaust manifold 7 to expel the gases produced by combustion inside cylinders 3 into the atmosphere. A turbosupercharger (not shown) may be provided downstream from exhaust manifold 7 and upstream from intake manifold 4, to exploit the kinetic energy of the exhaust gas to increase the speed and pressure of the fresh air intake through intake manifold 4.
Four injectors 12 (one for each cylinder 3) are fitted to intake pipes 5 to inject petrol cyclically into intake pipes 5; and four spark plugs 13 (one for each cylinder 3) are fitted to cylinders 3 to cyclically ignite the mixture inside cylinders 3.
Each cylinder 3 has a piston 14, which slides linearly along cylinder 3 and is connected mechanically by a connecting rod 16 to a drive shaft 15, in turn connected mechanically to a transmission 17 with the interposition of a clutch 18 to transmit drive torque to the drive wheels of the vehicle (not shown).
Power train 1 comprises a control system 19 for monitoring operation of power train 1. Control system 19 comprises at least one electronic control unit 20 (ECU) which monitors operation of power train 1, is located close to engine 2, and is normally housed inside the engine compartment of the vehicle (not shown); and a number of sensors 21 connected to control unit 20 to measure various operating parameters of power train 1 (e.g. the angular position and rotation speed of drive shaft 15) which are used by control unit 20 to control power train 1.
As shown in
As shown in
Processing the intensity of the pressure waves generated by power train 1 to determine the value of at least one operating parameter of power train 1 comprises processing the intensity of the pressure waves in frequency, and may comprise combining the intensity of the pressure waves with signals (e.g. temperature, vibration, or instantaneous speed signals) from other sensors 21.
In other words, at least one pressure sensor 21a is incorporated in control unit 20, and therefore outside engine block 22, to gather physical evidence concerning the operation of power train 1, with no direct connection (piping or contact) to engine block 22, but by gathering pressure waves (and therefore also acoustic noise, even in the non-audible range). The purpose of pressure sensor 21a is to extract operating quantities representing phenomena occurring in engine 2 or transmission 17, e.g. turbosupercharger rotation speed, the rotation speed of drive shaft 15, the rotation speed of a secondary shaft of transmission 17 (from which the engaged gear can be determined), and combustion status (e.g. detonation phenomena).
Sensor 21a is cheap and easy to use, by being installable with no difficulty whatsoever inside control unit 20. In this connection, it should be pointed out that, being separate from engine block 22, control unit 20 is subject to no mechanical or thermal stress, and need not be any particular shape or size (so that space can easily be found for sensor 21a). Moreover, control unit 20 being subject to no mechanical or thermal stress, sensor 21a incorporated in control unit 20 may be simple in design yet highly reliable.
| Number | Date | Country | Kind |
|---|---|---|---|
| 06425240.6 | Apr 2006 | EP | regional |
