Method to perform intake cam lift state transitions

A method of transitioning between a first intake valve state and a second, distinct valve state in an cylinder of an internal combustion engine, comprising the steps of:

• providing an instruction to shift an intake valve lift state from the first state to the second state,
• determining a instantaneous angular position of an intake cam and an exhaust cam,
• determining if an intake cam and an exhaust cam are in positions wherein the commanded shift will result in constant engine torque output before and after the commanded shift,
• adjusting the instantaneous angular position of the intake cam and the exhaust cam to provide constant torque before and after the commanded shift,
• commanding an actuator to shift an intake cam assembly from the first lift state to the second lift state and wherein an exit threshold of the actuator to shift an intake cam assembly from the first lift state to the second lift state is lower than an entrance threshold of the actuator to shift an intake cam assembly from the first lift state to the second lift state.

A method of transitioning between intake valve states in an internal combustion engine, comprising the steps of:

• monitoring current operating conditions of the internal combustion engine,
• determining that the current operating condition require a change in intake valve lift state,
• providing an instruction to shift an intake valve lift state from a first lift state to a second lift state,
• determining current phases of an intake cam and an exhaust cam,
• adjusting phases of the intake cam and exhaust cam to provide constant torque before and after the commanded shift,
• commanding an intake cam transition from the first lift state to the second lift state and wherein an exit threshold of the intake cam transition from the first lift state to the second lift state is lower than an entrance threshold of the intake cam transition from the first lift state to the second lift state.