CONTROLLING VARIABLE VALVE ACTUATION SYSTEM
A method of controlling a variable valve actuation system for an internal combustion engine having a plurality of cylinders, each of the plurality of cylinders having a variable valve actuator and in-cylinder pressure sensor is provided. Output of an in-cylinder pressure sensor is monitored at a predetermined crank angle Θp with an electronic control module. The output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders at the predetermined crank angle Θp is compared to a stored threshold value for in-cylinder pressure at the predetermined crank angle. A variable valve actuator is adjusted to adjust a crank angle Θc corresponding to when an intake valve of the monitored one of the plurality of cylinders closes when the output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders does not correspond to the stored threshold value.
1 . A method of controlling a variable valve actuation system for an internal combustion engine having a plurality of cylinders, each of the plurality of cylinders having a variable valve actuator and in-cylinder pressure sensor, the method comprising:
monitoring output of an in-cylinder pressure sensor, wherein the in-cylinder pressure sensor is in operable communication with one of a plurality of cylinders, at a predetermined crank angle Θ p with an electronic control module;
comparing the output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders at the predetermined crank angle Θ p to a stored threshold value for in-cylinder pressure at the predetermined crank angle; and
adjusting a variable valve actuator to adjust a crank angle Θ c corresponding to when an intake valve of the monitored one of the plurality of cylinders closes when the output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders does not correspond to the stored threshold value.
2 . The method of claim 1 , wherein the predetermined crank angle Θ p is from about twenty degrees before top dead center to about five degrees before top dead center.
3 . The method of claim 2 , wherein the predetermined crank angle Θ p is about ten degrees before top dead center.
4 . The method of claim 1 , wherein the threshold value for in-cylinder pressure is based upon an average pressure of the plurality of cylinders at the predetermined crank angle Θ p .
5 . The method of claim 4 , wherein the threshold value for in-cylinder pressure is an average pressure of the plurality of cylinders at the predetermined crank angle Θ p .
6 . The method of claim 1 , wherein the adjustment of the variable valve actuator closes the intake valve at an earlier crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is less than the stored threshold value.
7 . The method of claim 1 , wherein the adjustment of the variable valve actuator closes the intake valve at a later crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is more than the stored threshold value.
8 . The method of claim 1 , wherein the adjustment of the variable valve actuator is based upon a lookup table having adjustments based upon an amount of difference between the output of the in-cylinder pressure sensor of the first cylinder at the predetermined crank angle and the stored threshold value.
9 . A method of controlling a variable valve actuation system for an internal combustion engine having a plurality of cylinders, each of the plurality of cylinders having a variable valve actuator and in-cylinder pressure sensor, the method comprising:
monitoring output of an in-cylinder pressure sensor of a plurality of cylinders at a predetermined crank angle Θ p with an electronic control module;
generating a pressure setpoint value of the plurality of cylinders at a predetermined crank angle Θ p ;
comparing the output of each of the plurality of in-cylinder pressure sensors at the predetermined crank angle Θ p to the pressure setpoint value;
calculating a revised valve closing crank angle Θ c for each of the plurality of cylinders; and
adjusting a variable valve actuator to adjust the valve closing crank angle Θ c for each of the plurality of cylinders to the revised valve closing crank angle.
10 . The method of claim 9 , wherein the predetermined crank angle Θ p is from about twenty degrees before top dead center to about five degrees before top dead center.
11 . The method of claim 10 , wherein the predetermined crank angle Θ p is about ten degrees before top dead center.
12 . The method of claim 9 , wherein the adjustment of the variable valve actuator closes the intake valve at an earlier crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is less than the stored threshold value.
13 . The method of claim 9 , wherein the adjustment of the variable valve actuator closes the intake valve at a later crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is more than the stored threshold value.
14 . The method of claim 9 , wherein the adjustment of the variable valve actuator is based upon a lookup table having adjustments based upon an amount of difference between the output of the in-cylinder pressure sensor of the first cylinder at the predetermined crank angle Θ p and the pressure setpoint value.
15 . A physical computer program product, comprising a computer usable medium having an executable computer readable program code embodied therein, the executable computer readable program code for implementing a method of controlling a variable valve actuation system for an internal combustion engine having a plurality of cylinders, each of the plurality of cylinders having a variable valve actuator and in-cylinder pressure sensor, the method comprising:
monitoring output of an in-cylinder pressure sensor, wherein the in-cylinder pressure sensor is in operable communication with one of a plurality of cylinders, at a predetermined crank angle Θ p with an electronic control module;
comparing the output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders at the predetermined crank angle Θ p to a stored threshold value for in-cylinder pressure at the predetermined crank angle; and
adjusting a variable valve actuator to adjust a crank angle Θ c corresponding to when an intake valve of the monitored one of the plurality of cylinders closes when the output of the in-cylinder pressure sensor of the monitored one of the plurality of cylinders does not correspond to the stored threshold value.
16 . The method of claim 15 , wherein the predetermined crank angle Θ p is from about twenty degrees before top dead center to about five degrees before top dead center.
17 . The method of claim 16 , wherein the predetermined crank angle Θ p is about ten degrees before top dead center.
18 . The method of claim 15 , wherein the threshold value for in-cylinder pressure is based upon an average pressure of the plurality of cylinders at the predetermined crank angle.
19 . The method of claim 15 , wherein the adjustment of the variable valve actuator closes the intake valve at an earlier crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is more than the stored threshold value.
20 . The method of claim 15 , wherein the adjustment of the variable valve actuator closes the intake valve at a later crank angle Θ c2 before top dead center than the previous crank angle Θ c1 when the intake valve closed when the output of the in-cylinder pressure sensor of the first cylinder is more than the stored threshold value.