Method for estimation of indicated mean effective pressure for individual cylinders from crankshaft acceleration

An internal combustion engine controlled by an engine control algorithm including a method for inferring Indicated Mean Effective Pressure as total transient indicated engine torque, wherein said method includes the steps of:

• acquiring at least one crankshaft time stamp for use in determining a cylinder-specific engine velocity,
• calculating an incremental change in engine kinetic energy from the previously fired cylinder (j−1st) to the currently fired (jth) cylinder using said cylinder-specific engine velocity,
• equating said incremental change in engine kinetic energy to a change in energy-averaged cylinder torque (IMEP) from the previously-fired (j−1st) to a currently-fired (jth) cylinder,
• summing a plurality of said incremental changes in engine kinetic energy over time to determine a value of the transient component of indicated torque,
• determining a value of quasi-steady indicated engine torque, and
• adding said value of the transient component of indicated torque to said value of quasi-steady indicated engine torque to yield said Indicated Mean Effective Pressure.