Differential steering control for a continuously variable transmission machine
AssigneeCaterpillar Inc.
InventorsHarold D. Dabbs, Eric D. Stemler, Lance M. Cowper, Richard F. Shults
Life of this patent
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Abstract
A differential steering control system and method for a machine includes a motor for steering the machine in a leftwards or a rightwards direction, a continuously variable transmission for moving the machine in a forwards or a backwards direction, and a control unit connected to the motor and the continuously variable transmission. The control unit determines the speed of the continuously variable transmission and based upon the determined speed, modifies a speed of the motor in order to achieve/maintain a desired turn radius for the machine.
Claims22
A method of steering a machine having an engine, a continuously variable transmission, a steering differential, and a steering control system including a steering motor adapted to operate said steering differential for steering said machine in a leftward or rightward direction, said steering control system having an actuable steering device, the steering control system further including a control unit in electrical communication with said steering device, said engine, said continuously variable transmission, and said steering motor, and wherein said control unit is configured to monitor and control direction and speed of said machine, said method of steering comprising the following steps:
- a) said control unit determines at least one of a speed of said continuously variable transmission and a load on said engine;
- b) said control unit determines a desired turn radius of said machine based upon inputs from said steering device;
- and
- c) said control unit modifies speed of said steering motor in response to at least one or both of said determined speed of said continuously variable transmission and said load on said engine to maintain said desired turn radius.
A method of steering a machine having an engine, a hydromechanical transmission, a steering differential, and a steering control system, said steering control system having an actuable steering device, and including a steering motor adapted to operate said steering differential for steering said machine in a leftward or rightward direction, the steering control system including a pump for operating the steering motor, and further including a control unit in electrical communication with said steering device, said engine, said hydromechanical transmission, said pump, and said steering motor, and wherein said control unit is configured to monitor and control direction and speed of said machine, said method of steering comprising the following steps:
- a) said control unit determines at least one of a speed of said hydromechanical transmission and a load on said engine;
- b) said control unit determines a desired turn radius of said machine based upon inputs from said steering device;
- and
- c) said control unit modifies speed of said steering motor in response to at least one or both of said determined speed of said hydromechanical transmission and said load on said engine to maintain said desired turn radius.
A method of steering a machine having an engine, a continuously variable transmission having a generator and an electric drivetrain motor, a steering differential, and a steering control system having an electronically actuated steering device and a steering motor adapted to operate said steering differential for steering said machine in a leftward or rightward direction via inputs of said steering device, the steering control system including a control unit in electrical communication with a) said engine, b) said continuously variable transmission, and c) said steering motor, and d) said steering device, wherein said control unit is configured to monitor and control direction and speed of said machine, said method of steering said machine comprising the following steps:
- a) said control unit determines at least one of a speed of said drivetrain motor and a load on said engine;
- b) said control unit determines a desired turn radius of said machine based upon inputs from said steering device;
- and
- c) said control unit modifies speed of said steering motor in response to at least one or both of said determined speed of said drivetrain motor and said load on said engine to maintain said desired turn radius.
Dependencies are inferred from the claim text.