Rudder control system with adjustable solenoid on/off settings, solenoid burnout protection, and hydraulic system monitoring
AssigneeNorthrop Grumman Corporation
InventorRonald K. Richey
Life of this patent
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Abstract
A rudder control system having adjustable rudder drive turn off and “turn on,” and component wear monitoring. The rudder drive “turn off” being adjusted in accordance with the rudder stop position relative to the rudder order stop position, thereby improving position accuracy. Frequency of system “turn on” is compared to an acceptable “turn on” frequency for solenoid operation. Should the “turn on” frequency exceed the acceptable “turn on” frequency, the rudder angle at which “turn on” is implemented is adjusted to protect solenoids in the system from burnout. The rate of change of the rudder repeatback signal is monitored. A slow rate of change providing an indication of some component problem.
Claims14
A method for positioning a rudder of a ship wherein the rudder is driven by a rudder drive system in accordance with a rudder error determined by the difference between a rudder position and a rudder order, the rudder drive system including a solenoid energized at a set rudder error, said solenoid coupled to an hydraulic pump which is activated when said solenoid is energized, comprising the steps of:
- establishing an energizing frequency for solenoid burnout protection thereby providing a burnout protection frequency;
- monitoring solenoid energizing frequency:
- determining when said solenoid is being energized at an energizing frequency that exceeds said burnout protection frequency;
- and
- adjusting said set rudder error to a second set rudder error when said energizing frequency exceeds said burnout protection frequency.
A rudder positioning apparatus for a ship including an hydraulic system having solenoids energized at a set rudder position error, to activate pumps, of the hydraulic system, a rudder position error being determined by the difference between a rudder position and a rudder order, comprising:
- a frequency detector coupled to said hydraulic system to determine frequency of said hydraulic system turn on, and
- a solenoid turn on adjuster coupled to said solenoid of said hydraulic system and said frequency detector for adjusting said set rudder position error when said frequency detector indicates that a predetermined frequency of solenoid energizations has been exceeded.
Dependencies are inferred from the claim text.