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US 11,421,587 B2Granted
Method and system for diagnosing and/or controlling a reciprocating engine having a variable compression ratio
AssigneeAVL List GmbH
InventorPhilip Williams
Life of this patent
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Abstract
The invention relates to a method for diagnosing and/or controlling a reciprocating engine having a variable compression ratio, wherein the method comprises the working steps: determining (S30) a first value (U1,1, U1,2; Δ1) of a rotational irregularity parameter of a crankshaft (1) of the reciprocating engine; and determining (S60) a value of a compression ratio parameter for the reciprocating engine based on said first rotational irregularity parameter value.
Claims16
A method of diagnosing or controlling a reciprocating piston engine with a variable compression ratio, comprising:
- detecting at least one of a crank angle of a crankshaft of the reciprocating piston engine and at least one time derivative of the crank angle;
- determining a first value of a rotational irregularity parameter of the crankshaft on the basis of the at least one of the detected crank angle and the at least one time derivative for a first target compression ratio of at least a first cylinder of the reciprocating piston engine,
- wherein the first value of the rotational irregularity parameter is determined for at least one specified crank angle region extending over from at least 2° to at most 135° and comprising at least one of a top dead center and a bottom dead center of the first cylinder;
- changing a target compression ratio of the first cylinder of the reciprocating piston engine from the first target compression ratio to a second target compression ratio;
- determining a second value of the rotational irregularity parameter of the crankshaft for the second target compression ratio;
- determining a value of a compression ratio parameter for the reciprocating piston engine on the basis of the first and second values of the rotational irregularity parameter;
- and
- outputting a signal if the value of the compression ratio parameter satisfies a specified condition.
5 more elements
A system for diagnosing or controlling a reciprocating piston engine with a variable compression ratio, comprising:
- a sensor for detecting at least one of a crank angle of a crankshaft of the reciprocating piston engine and at least one time derivative of the crank angle;
- and
- an engine control unit for:
- determining a first value of a rotational irregularity parameter of the crankshaft on the basis of the at least one of the detected crank angle and the at least one time derivative for a first target compression ratio of at least a first cylinder of the reciprocating piston engine,
- wherein the first value of the rotational irregularity parameter is determined for at least one specified crank angle region extending over from at least 2° to at most 135° and comprising at least one of a top dead center and a bottom dead center of the first cylinder;
- changing a target compression ratio of the first cylinder of the reciprocating piston engine from the first target compression ratio to a second target compression ratio;
- determining a second value of the rotational irregularity parameter of the crankshaft for the second target compression ratio;
- determining a value of a compression ratio parameter for the reciprocating piston engine on the basis of the first and second values of the rotational irregularity parameter;
- and
- outputting a signal if the value of the compression ratio parameter satisfies a specified condition.
7 more elements
A motorized vehicle, comprising:
- a reciprocating piston engine with a variable compression ratio that includes a first cylinder coupled to a crankshaft by a piston rod having an adjustable length;
- and
- a system for controlling the reciprocating piston engine which includes:
- a sensor for detecting at least one of a crank angle of the crankshaft and at least one time derivative of the crank angle;
- and
- an engine control unit for:
- determining a first value of a rotational irregularity parameter of the crankshaft on the basis of the at least one of the detected crank angle and the at least one time derivative for a first target compression ratio of at least the first cylinder of the reciprocating piston engine,
- wherein the first value of the rotational irregularity parameter is determined for at least one specified crank angle region extending over from at least 2° to at most 135° and comprising at least one of a top dead center and a bottom dead center of the first cylinder;
- changing a target compression ratio of the first cylinder of the reciprocating piston engine from the first target compression ratio to a second target compression ratio;
- determining a second value of the rotational irregularity parameter of the crankshaft for the second target compression ratio;
- determining a value of a compression ratio parameter for the reciprocating piston engine on the basis of the first and second values of the rotational irregularity parameter;
- and
- outputting a signal if the value of the compression ratio parameter satisfies a specified condition.
10 more elements
Dependencies are inferred from the claim text.