Systems and Methods for Steering Control for a Hydraulic Machine

A steering system for a hydraulic machine having a pump, an actuator, and a tank, the steering system comprising:

• a manual steering valve including a first pump connection, a first tank connection, a first actuator connection, and a second actuator connection, the manual steering valve configured to selectively couple the first pump connection, the first tank connection, the first actuator connection, and the second actuator connection;
• and
• an electronic steering valve including:
• a valve body defining a pump port configured to couple to the pump, a first actuator port configured to couple to the actuator, a second actuator port configured to couple to the actuator, a tank port configured to couple to the tank, a second pump connection configured to couple to the first pump connection, a second tank connection configured to couple to the first tank connection, a third actuator connection configured to couple to the first actuator connection, and a fourth actuator connection configured to couple to the second actuator connection;
• a directional control spool disposed within the valve body, the directional control spool configured to selectively couple the pump port, the first actuator port, the second actuator port, and the tank port;
• and
• an isolator spool disposed within the valve body, the isolator spool configured to switch the steering system between a manual steering mode, in which the directional control spool is decoupled from the pump port, the first actuator port, and the second actuator port by the isolator spool, an electronic steering mode, in which the directional control spool is coupled to the pump port, the first actuator port, and the second actuator port by the isolator spool.