Measuring and testing – Vehicle chassis – Steering
Patent
1995-02-27
1996-05-28
Chilcot, Richard
Measuring and testing
Vehicle chassis
Steering
36443101, 73115, G01M 1500
Patent
active
055200435
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The invention is based on a device for crankshaft-synchronous detection of a periodically changing variable in an internal combustion engine, in particular the load, of the generic type of the main claim.
It is known that the negative pressure in the induction pipe of an internal combustion engine pulsates in time with the power cycle of the internal combustion engine. However, in order to control the internal combustion engine precisely the actual air flow rate is required. In many cases, an equivalent variable such as the average value of the induction pipe pressure is used. Therefore, it is proposed for example in the German Offenlegungsschrift DE-A 38 03 276 to sense the induction pipe pressure in an angle-synchronous fashion twice per period length and to damp either the signal obtained or the induction pipe pressure itself by means of suitable filters in such a way that a quasi-sinusoidal signal characteristic is obtained. If this signal is sampled twice per ignition interval, the average value can be calculated directly from two successive values.
For modern internal combustion engines this average value formation is still too imprecise. Furthermore, with this method it is only possible to determine the average value and not the precise pressure characteristic or the precise air flow rate, but this is precisely what is desired for some control measures.
ADVANTAGES OF THE INVENTION
In contrast, the device according to the invention with the characterizing features of the main claim has the advantage that, on the one hand, a very precise average value formation is possible and, on the other hand, the precise induction pipe pressure characteristic or the precise characteristic of the quantity of air inducted can be determined. It is therefore also possible to determine precisely the quantity of air inducted per power cycle. Overall, a particularly precise and reliable load determination is possible.
Furthermore, it is advantageous that the achieved measured values can be compared with one another from segment to segment and thus from power cycle to power cycle, and at the same time it is possible to form average values which are associated with the individual segments and are then also available for controlling the internal combustion engine.
These advantages are achieved in that the signal characteristic is sampled with a high sampling rate, the start of the sampling being synchronized in relation to the crankshaft and the sampling therefore starting at the same point for each segment. This promotes synchronization with the periodically oscillating load signal. By integrating over a power cycle the associated quantity of air inducted is calculated.
Suitable filtering of the periodically oscillating signal can be carried out before sampling but, in contrast with the solution disclosed in the German Offenlegungsschrift DE-A 38 03 276, is not absolutely necessary.
By means of the measures specified in the subclaims, advantageous developments of the device disclosed in the main claim are possible.
DRAWING
The invention is illustrated in the drawings and is explained in greater detail in the subsequent description. In particular, FIG. 1 shows a diagrammatic illustration of the device according to the invention. In FIGS. 2a, 2b and 2c, associated signal sequences are illustrated by means of which the invention is explained.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
In FIG. 1, the parts of an internal combustion engine which are essential to the invention are illustrated diagrammatically. Here, 10 designates the control unit, 11 the crankshaft and 12 a disc which is connected to the crankshaft 11 and rotates therewith.
The surface of the disc 12 has a number of marks 13a, 13b, 13c which is matched to the number of cylinders of the internal combustion engine. In the case illustrated in FIG. 1 there are three marks, such a disc is used in a 6-cylinder internal combustion engine. A region which is designated by CA forms a so-called segment. This region is defined in FIG. 1 as an angle between
REFERENCES:
patent: 3886817 (1975-06-01), Paul et al.
patent: 4343180 (1982-08-01), Herden et al.
patent: 4403505 (1983-09-01), Hattori et al.
patent: 4424709 (1984-01-01), Meier et al.
patent: 5076098 (1991-12-01), Miwa
patent: 5125267 (1992-06-01), Kuroda et al.
patent: 5127262 (1992-07-01), Demizu et al.
patent: 5321979 (1994-06-01), McKendry et al.
patent: 5359518 (1994-10-01), Wimmes
patent: 5359519 (1994-10-01), Jehanno
patent: 5400648 (1995-03-01), Mahr
Koelle Ulrich
Lock Andreas
Roth Andreas
Chilcot Richard
Dombroske George M.
Robert & Bosch GmbH
Striker Michael J.
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