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US 11,731,688 B2Granted
Differential steering control vehicle, system and method
AssigneeCNH Industrial America LLC
InventorsPhilip J. Ehrhart, Madhu Pankaj, Robert L. Fackler
Life of this patent
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Abstract
A method of differentially steering a hydraulically driven vehicle includes measuring left and right swash plate angles of pumps which drive left and right wheels of the vehicle and if the angles are different from one another and the larger swash plate angle is equal to or exceeds a threshold value then reducing the larger swash plate angle. If the larger swash plate angle is between the threshold value and a lower limit, or below the lower limit the swash plate angle is increased. Control systems and vehicles include swash plate angle sensors and actuators in communication with a controller which effects the steering control method.
Claims20
A method of steering a vehicle having at least a left wheel and a right wheel oppositely disposed, torque being applied to said left wheel by a left hydraulic pump having a left swash plate, torque being applied to said right wheel by a right hydraulic pump having a right swash plate, said method comprising:
- measuring a left swash plate angle of said left swash plate;
- measuring a right swash plate angle of said right swash plate;
- comparing said left swash plate angle to said right swash plate angle;
- comparing said left swash plate angle to a left angle threshold if said left swash plate angle is greater than said right swash plate angle;
- comparing said right swash plate angle to a right angle threshold if said right swash plate angle is greater than said left swash plate angle;
- reducing said left swash plate angle if said left swash plate angle is equal to or greater than said left angle threshold;
- reducing said right swash plate angle if said right swash plate angle is equal to or greater than said right angle threshold;
- and
- repeating said measuring, comparing and reducing steps.
6 more elements
A control system for steering a vehicle having at least a left wheel and a right wheel oppositely disposed, torque being applied to said left wheel by a left hydraulic pump having a left swash plate, torque being applied to said right wheel by a right hydraulic pump having a right swash plate, said control system comprising:
- a controller;
- a left swash plate sensor in communication with said controller, said left swash plate sensor for measuring a left swash plate angle and sending signals indicative of said left swash plate angle to said controller;
- a right swash plate sensor in communication with said controller, said right swash plate sensor for measuring a right swash plate angle and sending signals indicative of said right swash plate angle to said controller;
- a left swash plate actuator in communication with said controller for adjusting said left swash plate angle of said left swash plate;
- and
- a right swash plate actuator in communication with said controller for adjusting said right swash plate angle of said right swash plate;
- wherein
- said controller having programmed instructions to:
- compare said left and right swash plate angles with one another;
- compare said left swash plate angle to a left angle lower limit in response to a determination that said left swash plate angle is greater than said right swash plate angle;
- compare said right swash plate angle to a right angle lower limit in response to a determination that said right swash plate angle is greater than said left swash plate angle;
- control said left swash plate actuator to increase said left swash plate angle in response to a determination that said left swash plate angle is less than said left angle lower limit;
- and
- control said right swash plate actuator to increase said right swash plate angle in response to a determination that said right swash plate angle is less than said right angle lower limit.
11 more elements
A control system for steering a vehicle having at least a left wheel and a right wheel oppositely disposed, torque being applied to said left wheel by a left hydraulic pump having a left swash plate, torque being applied to said right wheel by a right hydraulic pump having a right swash plate, said control system comprising:
- a controller;
- a left swash plate sensor in communication with said controller, said left swash plate sensor for measuring a left swash plate angle and sending signals indicative of said left swash plate angle to said controller;
- a right swash plate sensor in communication with said controller, said right swash plate sensor for measuring a right swash plate angle and sending signals indicative of said right swash plate angle to said controller;
- and
- at least one swash plate actuator in communication with said controller for adjusting said left swash plate angle of said left swash plate and said right swash plate angle of said right swash plate;
- wherein
- said controller having programmed instructions to:
- compare said left and right swash plate angles with one another;
- compare said left swash plate angle to a left angle threshold in response to a determination that said left swash plate angle is greater than said right swash plate angle;
- compare said right swash plate angle to a right angle threshold in response to a determination that said right swash plate angle is greater than said left swash plate angle;
- control said at least one swash plate actuator to reduce said left swash plate angle in response to a determination that said left swash plate angle is greater than said left angle threshold;
- and
- control said at least one swash plate actuator to reduce said right swash plate angle in response to a determination that said right swash plate angle is greater than said right angle threshold.
10 more elements
A differentially steered vehicle, said vehicle comprising:
- a chassis having an engine and a plurality of wheels mounted thereon including a left wheel and a right wheel disposed on opposite sides of said vehicle;
- a left hydraulic motor operatively associated with said left wheel;
- a right hydraulic motor operatively associated with said right wheel;
- a left hydraulic pump driven by said engine, said left hydraulic pump operatively associated with said left hydraulic motor and having a left swash plate;
- a right hydraulic pump driven by said engine, said right hydraulic pump operatively associated with said right hydraulic motor and having a right swash plate;
- a controller;
- a left swash plate sensor in communication with said controller, said left swash plate sensor for measuring a left swash plate angle and sending signals indicative of said left swash plate angle to said controller;
- a right swash plate sensor in communication with said controller, said right swash plate sensor for measuring a right swash plate angle and sending signals indicative of said right swash plate angle to said controller;
- a left swash plate actuator in communication with said controller for adjusting said left swash plate angle of said left swash plate;
- and
- a right swash plate actuator in communication with said controller for adjusting said right swash plate angle of said right swash plate;
- wherein
- said controller having programmed instructions to:
- compare said left swash plate angle to a left angle threshold in response to a determination that said left swash plate angle is greater than said right swash plate angle;
- compare said right swash plate angle to a right angle threshold in response to a determination that said right swash plate angle is greater than said left swash plate angle;
- control said left swash plate actuator to reduce said left swash plate angle in response to a determination that said left swash plate angle is greater than said left angle threshold;
- and
- control said right swash plate actuator to reduce said right swash plate angle in response to a determination that said right swash plate angle is greater than said right angle threshold.
15 more elements
A differentially steered vehicle, said vehicle comprising:
- a chassis having an engine and a plurality of wheels mounted thereon including a left wheel and a right wheel disposed on opposite sides of said vehicle;
- a left hydraulic motor operatively associated with said left wheel;
- a right hydraulic motor operatively associated with said right wheel;
- a left hydraulic pump driven by said engine, said left hydraulic pump operatively associated with said left hydraulic motor and having a left swash plate;
- a right hydraulic pump driven by said engine, said right hydraulic pump operatively associated with said right hydraulic motor and having a right swash plate;
- a controller;
- a left swash plate sensor in communication with said controller, said left swash plate sensor for measuring a left swash plate angle and sending signals indicative of said left swash plate angle to said controller;
- a right swash plate sensor in communication with said controller, said right swash plate sensor for measuring a right swash plate angle and sending signals indicative of said right swash plate angle to said controller;
- and
- at least one swash plate actuator in communication with said controller for adjusting said left swash plate angle of said left swash plate and said right swash plate angle of said right swash plate;
- wherein
- said controller having programmed instructions to:
- compare said left swash plate angle to a left angle threshold in response to a determination that said left swash plate angle is greater than said right swash plate angle;
- compare said right swash plate angle to a right angle threshold in response to a determination that said right swash plate angle is greater than said left swash plate angle;
- control said at least one swash plate actuator to increase said left swash plate angle in response to a determination that said left swash plate angle is less than said left angle threshold;
- and
- control said at least one swash plate actuator to increase said right swash plate angle in response to a determination that said right swash plate angle is less than said right angle threshold.
14 more elements
Dependencies are inferred from the claim text.