Open loop machine motor speed control based on downhill slope determination

A non-transitory computer-readable medium including computer-executable instructions, executable by a programmed controller, for managing operation of a machine to prevent movable machine components from reaching excessive speed while the machine is traveling down a steep incline, the computer-executable instructions facilitating performing the steps of:

• determining a downhill slope value in a machine direction of travel;
• establishing a maximum commanded transmission output speed in accordance with the determined downhill slope value;
• establishing a maximum commanded gear ratio, for a transmission having a variable gear ratio, based upon the maximum commanded transmission output speed and a current engine speed;
• comparing the maximum commanded variable gear ratio to an operator requested gear ratio;
• establishing a target gear ratio for the variable gear ratio of the transmission based upon a minimum of the compared commanded variable gear ratio and the operator requested gear ratio;
• and
• issuing the target gear ratio to a controller for the transmission, thereby ensuring that the target gear ratio provided to the controller for the transmission does not exceed the maximum commanded variable gear ratio for a current determined value for the downhill slope value in the machine direction of travel.

A machine comprising:

• a traction drive;
• an engine;
• a transmission providing power from the engine to the traction drive, the transmission having a variable gear ratio;
• and
• a programmed controller configured with a non-transitory computer-readable medium including computer-executable instructions for managing operation of the machine to prevent movable machine components from reaching excessive speed while the machine is traveling down a steep incline, the computer-executable instructions facilitating performing the steps of:
• determining a downhill slope value in a machine direction of travel;
• establishing a maximum commanded transmission output speed in accordance with the determined downhill slope value;
• establishing a maximum commanded gear ratio, for the transmission, based upon the maximum commanded transmission output speed and a current engine speed;
• comparing the maximum commanded variable gear ratio to an operator requested gear ratio;
• establishing a target gear ratio for a variable transmission based upon a minimum of the compared commanded variable gear ratio and the operator requested gear ratio;
• and
• issuing the target gear ratio to a controller for the transmission, thereby ensuring that the target gear ratio provided to the controller for the transmission does not exceed the maximum commanded variable gear ratio for a current determined value for the downhill slope value in the machine direction of travel.