End of motion detection circuit for diesel engines

A method of synchronizing output signals from an engine control unit (ECU) to a diesel injection valve, the valve having a first coil for opening the valve and a second coil for closing the valve, the method comprising:

• comparing a back electromotive feedback (BEMF) signal received from the valve to a first threshold, thereby defining a first output,
• filtering the BEMF signal thereby providing a filtered BEMF signal,
• detecting an end of motion of the valve by comparing a difference between the BEMF signal and the filtered BEMF signal to a second threshold, thereby defining a second output,
• joining the first output with the second output to define an output signal,
• activating the output signal only when the BEMF signal is above the first threshold and when the difference between the BEMF signal and the filtered BEMF signal is greater than the second threshold,
• receiving activated output signal at the ECU,
• synchronizing control signals sent by the ECU to the valve based on end of motion of the valve,
• wherein the detecting step includes subtracting the BEMF signal from a moving average of the filtered BEMF signal, thereby defining said difference.

A method of detecting end of motion of a diesel injection valve, the valve having a first coil for opening the valve and a second coil for closing the valve, the method comprising:

• comparing an back electromotive feedback (BEMF) signal received from the valve to a first threshold, thereby defining a first output,
• filtering the BEMF signal thereby providing a filtered BEMF signal,
• detecting an end of motion of the valve by comparing a difference between the BEMF signal and the filtered BEMF signal to a second threshold, thereby defining a second output,
• joining the first output with the second output to define an output signal, and
• activating the output signal only when the BEMF signal is above the first threshold and when the difference between the BEMF signal and the filtered BEMF signal is greater than the second threshold,
• wherein the detecting step includes subtracting the BEMF signal from a moving average of the filtered BEMF signal, thereby defining said difference.