Apparatus and method for analyzing events for an internal combustion engine
First Claim
1. An apparatus for analyzing a plurality of events of an internal combustion engine having at least one cylinder, a rotatable crankshaft and a reciprocating piston, the cylinder having a fuel injector, an intake valve and an exhaust valve, comprising:
- a crankshaft sensor being adapted to monitor the rotational position of the crankshaft and responsively produce a crankshaft pulsetrain;
a cylinder pressure sensor being adapted to sense the pressure produced in the engine cylinder and responsively produce a cylinder pressure signal corresponding to predetermined crankshaft positions;
memory means for storing precalculated values representing a plurality of engine cylinder volumes at predetermined crankshaft positions; and
processing means for receiving the crankshaft pulsetrain and cylinder pressure signals and determining the start of combustion for occurring engine cycle relative to the crankshaft position in response to the cylinder pressure signal magnitude, P2, at a current crankshaft position being equal or greater than the following relationship;
space="preserve" listing-type="equation">P.sub.1 (V.sub.1 /V.sub.2).sup.nwhere,P1 =cylinder pressure corresponding to a previous crankshaft position;
V1 =cylinder volume corresponding to the previous crankshaft position;
V2 =cylinder volume corresponding to the current crankshaft position; and
n=predetermined polytropic value;
wherein the start of combustion is determined prior to the next occurring engine cycle.
1 Assignment
0 Petitions
Accused Products
Abstract
In one aspect of the present invention, an apparatus for analyzing a plurality of events of an internal combustion engine is provided. A crankshaft sensor monitors the rotational position of the crankshaft and responsively produces a crankshaft pulsetrain. A cylinder pressure sensor senses the pressure produced in the engine cylinder and responsively produces a cylinder pressure signal. A memory device stores previously calculated values representing engine cylinder volumes at predetermined crankshaft positions. A microprocessor determines the start of combustion for an occurring engine cycle in response to a cylinder pressure signal magnitude, P2, at a current crankshaft position being equal or greater than the relationship:
P.sub.1 (V.sub.1 /V.sub.2).sup.n
where, P1 equals the cylinder pressure corresponding to a previous crankshaft position, V1 equals cylinder volume corresponding to the previous crankshaft position, V2 equals the cylinder volume corresponding to the current crankshaft position, and n equals a predetermined polytropic value. Advantageously, the start of combustion is determined prior to the next occurring engine cycle.
40 Citations
17 Claims
-
1. An apparatus for analyzing a plurality of events of an internal combustion engine having at least one cylinder, a rotatable crankshaft and a reciprocating piston, the cylinder having a fuel injector, an intake valve and an exhaust valve, comprising:
-
a crankshaft sensor being adapted to monitor the rotational position of the crankshaft and responsively produce a crankshaft pulsetrain; a cylinder pressure sensor being adapted to sense the pressure produced in the engine cylinder and responsively produce a cylinder pressure signal corresponding to predetermined crankshaft positions; memory means for storing precalculated values representing a plurality of engine cylinder volumes at predetermined crankshaft positions; and processing means for receiving the crankshaft pulsetrain and cylinder pressure signals and determining the start of combustion for occurring engine cycle relative to the crankshaft position in response to the cylinder pressure signal magnitude, P2, at a current crankshaft position being equal or greater than the following relationship;
space="preserve" listing-type="equation">P.sub.1 (V.sub.1 /V.sub.2).sup.nwhere, P1 =cylinder pressure corresponding to a previous crankshaft position; V1 =cylinder volume corresponding to the previous crankshaft position; V2 =cylinder volume corresponding to the current crankshaft position; and n=predetermined polytropic value; wherein the start of combustion is determined prior to the next occurring engine cycle. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for analyzing a plurality of events of an internal combustion engine having at least one cylinder and a rotatable crankshaft, the cylinder having a fuel injector, an intake valve, an exhaust valve and a reciprocating piston, comprising the steps:
-
monitoring the rotational position of the crankshaft and responsively producing a crankshaft pulsetrain; sensing the pressure produced in the engine cylinder and responsively producing a cylinder pressure signal corresponding to predetermined crankshaft positions; storing precalculated values representing a plurality of engine cylinder volumes at predetermined crankshaft positions; and receiving the crankshaft pulsetrain and cylinder pressure signals and determining the start of combustion for an occurring engine cycle relative to the crankshaft position in response to a cylinder pressure signal magnitude, P2, at a current crankshaft position being equal or greater that the following relationship;
space="preserve" listing-type="equation">P.sub.1 (V.sub.1 /V.sub.2).sup.nwhere, P1 =cylinder pressure corresponding to a previous crankshaft position; V1 =cylinder volume corresponding to the previous crankshaft position; V2 =cylinder volume corresponding to the current crankshaft position; and n=predetermined polytropic value; wherein the start of combustion is determined prior to the next occurring engine cycle. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
Specification