Straight tracking control system for a machine with a dual path electronically controlled hydrostatic transmission

A control system for a machine comprising:

• a first drive system comprising:
• a first forward solenoid and a first reverse solenoid;
• a first pump controlled by the first forward solenoid and the first reverse solenoid;
• and
• a first motor powered by the first pump;
• a second drive system comprising:
• a second forward solenoid and a second reverse solenoid;
• a second pump controlled by the second forward solenoid and the second reverse solenoid;
• and
• a second motor powered by the second pump;
• an operator input device, the operator input device generating a first command to control the first drive system and a second command to control the second drive system in response to user manipulation of the operator input device;
• a first sensor to measure a speed of the first motor;
• a second sensor to measure a speed of the second motor;
• a controller to generate a control value using the measured speed of the first motor and the measured speed of the second motor in response to the first command and the second command being equal;
• a subtractor to generate a control signal for the first forward solenoid and the first reverse solenoid using the control value and the first command;
• and
• the second forward solenoid and the second reverse solenoid receiving the second command.