Abstract: An adaptive engine speed control system for a grass mowing machine having an internal combustion engine, a hydrostatic traction drive circuit and a hydraulic mowing circuit for operating a plurality of cutting units. A controller provides a traction feedback output signal if the grass mowing machine is moving at an actual ground speed that is below a pedal based desired ground speed, and uses the traction feedback output signal to command the internal combustion engine to an increased speed above a pedal based engine speed control range.

Abstract: An adaptive engine speed control system for a grass mowing machine having an internal combustion engine, a hydrostatic traction drive circuit and a hydraulic mowing circuit for operating a plurality of cutting units. A controller provides a traction feedback output signal if the grass mowing machine is moving at an actual ground speed that is below a pedal based desired ground speed, and uses the traction feedback output signal to command the internal combustion engine to an increased speed above a pedal based engine speed control range.

Abstract: An electric lawn tractor roll away prevention system includes a brushless DC electric motor powering a traction drive wheel on the electric lawn tractor. The motor is connected to phase wires and provides a back EMF voltage on the phase wires if the electric lawn tractor rolls and turns the traction drive wheel without electric power from the motor. A three phase inverter rectifies the back EMF voltage, turns on the traction controller if the rectified voltage reaches a pre-specified threshold, and applies a voltage to the phase wires to reduce the speed of the electric lawn tractor by regenerative braking.

Abstract: An electric lawn tractor roll away prevention system includes a brushless DC electric motor powering a traction drive wheel on the electric lawn tractor. The motor is connected to phase wires and provides a back EMF voltage on the phase wires if the electric lawn tractor roils and turns the traction drive wheel without electric power from the motor. A three phase inverter rectifies the back EMF voltage, turns on the traction controller if the rectified voltage reaches a pre-specified threshold, and applies a voltage to the phase wires to reduce the speed of the electric lawn tractor by regenerative braking.

Abstract: A system to clear stuck reels on a grass mowing machine with a reversible electric or hydraulic motor connected to a cutting reel. The reel motor can rotate in a forward direction and a reverse direction. A controller provides electric signals to the reel motor, and commands the motor to reverse direction if the reel motor does not rotate in the forward direction at a rotational speed at least as high as a preset minimum speed, or rotate a pre-specified number of revolutions.