System and method for servo control of nonlinear electromagnetic actuators

A solenoid having a core of a material which minimizes core loss at a predetermined frequency comprising:

• a. a drive coil;
• b. an armature capable of movement within said drive coil;
• c. a yoke coupled to said drive coil, wherein said yoke is positioned in relation to said armature such that there is at least one air gap between said yoke and said armature;
• and
• d. control means including a drive coil controller coupled to said drive coil, wherein said control means regulates movement of said armature within said drive coil based upon measurements of current and an oscillatory characteristic of the current from said drive coil.

A solenoid comprising:

• a drive coil;
• an armature capable of movement within said drive coil;
• a yoke coupled to said drive coil, wherein said yoke is positioned in relation to said armature such that there is at least one air gap between said yoke and said armature;
• control means including a drive coil controller coupled to said drive coil, wherein said control means regulates movement of said armature within said drive coil based upon electrical measurements from said drive coil;
• and
• launch control means for computing and initiating drive coil signals for movement of said armature with minimal electrical power consumption.

A method for controlling the duration of a drive pulse transmitted to a drive coil of a solenoid having an armature and a yoke so as to move said armature to a prescribed position, said method comprising the steps of:

• a. supplying a drive pulse to said drive coil for movement of said armature in relation to said yoke;
• b. determining a signal sensitive to movement of said armature;
• c. defining as a function of time a threshold for said signal sensitive to said movement;
• d. comparing said signal with said threshold;
• and
• e. terminating said drive pulse either when said signal substantially corresponds with said threshold, or when a predefined time limit is reached.

A solenoid comprising:

• a drive coil;
• an armature capable of movement within said drive coil;
• control means including a drive coil controller coupled to said drive coil, wherein said control means regulates movement of said armature within said drive coil based upon electrical measurements from said drive coil;
• and
• wherein said solenoid is a reciprocating pump actuator which drives the pump, said solenoid further comprising means for identifying pre-loading of said armature through actuation of said drive coil.