Camshaft phase error monitoring

A control system for controlling a valve actuator for an internal combustion engine, the control system comprising one or more controllers, the control system being configured to:

• receive a requirement signal indicative of a requirement for valve actuation with a first valve timing characteristic;
• receive an expected flow signal indicative of an expected mass flow rate of air associated with the first valve timing characteristic;
• control the valve actuator to provide the first valve timing characteristic;
• receive an actual flow signal indicative of an actual mass flow rate of air associated with the control of the valve actuator;
• cause comparison of the actual flow signal with the expected flow signal;
• and
• cause an action to be performed in dependence on the comparison, wherein the action comprises at least one of a compensation action, a fault reporting action, and determining camshaft phase information.

A method for controlling a valve actuator for an internal combustion engine, the method comprising:

• receiving a requirement signal indicative of a requirement for valve actuation with a first valve timing characteristic;
• receiving an expected flow signal indicative of an expected mass flow rate of air associated with the first valve timing characteristic;
• controlling the valve actuator to provide the first valve timing characteristic;
• receiving an actual flow signal indicative of an actual mass flow rate of air associated with the control of the valve actuator;
• causing comparison of the actual flow signal with the expected flow signal;
• and
• causing an action to be performed in dependence on the comparison, wherein the action comprises at least one of a compensation action, a fault reporting action, and determining camshaft phase information.