Method of dynamic speed modulation in extended braking applications in electric vehicles

A controller for use in association with a power system of a battery-powered electric vehicle to achieve dynamic speed modulation in extended braking applications, wherein the power system of the electric vehicle comprises:

• at least one electric motor operatively connected to a drive train of the vehicle;
• a rechargeable battery for supply of power to the at least one electric motor;
• and
• a regenerative braking system operatively connected to the at least one electric motor which progressively limits the groundspeed of the vehicle and provides recharging power to the battery;
• wherein the controller contains a processor and control software and is operatively connected to the power system of the electric vehicle so as to be capable of:
• monitoring a sensed parameter of the battery, and the current groundspeed of the vehicle;
• determining a change in the parameter which would be caused by the regenerative braking system at the current groundspeed of the vehicle;
• and
• adjusting the current groundspeed of the vehicle between zero and a maximum operating groundspeed;
• and
• wherein the controller, during operation of the vehicle, facilitates the dynamic speed modulation in extended braking applications by continually executing the steps of:
• a) determining the sensed parameter of the battery;
• b) determining a parameter threshold of the battery;
• c) if the sensed parameter of the battery is the same or exceeds the parameter threshold, reducing the maximum groundspeed to a predetermined safe speed;
• d) if the sensed parameter of the battery is below the parameter threshold, determining the change in the parameter which would be caused by the regenerative braking system at the current groundspeed of the vehicle;
• e) if the change in the parameter would cause the sensed parameter to reach or exceed the parameter threshold, decreasing the groundspeed of the vehicle to one at which the change in the parameter caused by the regenerative braking system would cause the sensed parameter to approximate but not exceed the parameter threshold of the battery;
• and
• f) if the change in the parameter would cause the sensed parameter to remain within the parameter threshold, increasing the groundspeed of the vehicle to one at which the change in the parameter caused by the regenerative braking system would cause the sensed parameter to approximate but not exceed the parameter threshold of the battery and which does not exceed the maximum operating groundspeed.

A battery powered electric vehicle configured to achieve dynamic speed modulation in extended braking applications, said vehicle comprising:

• a. at least one electric motor operatively connected to a drive train of the vehicle;
• b. a rechargeable battery for supply of power to the at least one electric motor;
• and
• c. a regenerative braking system operatively connected to the at least one electric motor which progressively limits the groundspeed of the vehicle and provides recharging power to the battery;
• and
• d. a controller for use in association with a power system of the vehicle comprising a processor and associated control software, being operatively connected to the power system of the electric vehicle so as to be capable of:
• i. monitoring a sensed parameter of the battery, and the current groundspeed of the vehicle;
• ii. determining a change in the parameter which would be caused by the regenerative braking system at the current groundspeed of the vehicle;
• and
• iii. adjusting the current groundspeed of the vehicle between zero and a maximum operating groundspeed;
• wherein the controller, during operation of the vehicle, facilitates the dynamic speed modulation in extended braking applications by continually executing the steps of:
• a. determining the sensed parameter of the battery;
• b. determining a parameter threshold of the battery;
• c. if the sensed parameter of the battery is the same or exceeds the parameter threshold, decreasing the groundspeed to a predetermined safe speed;
• d. if the sensed parameter of the battery is below the parameter threshold, determining the change in the parameter which would be caused by the regenerative braking system at the current groundspeed of the vehicle;
• e. if the change in the parameter would cause the sensed parameter to reach or exceed the parameter threshold, decreasing the groundspeed of the vehicle to one at which the change in the parameter caused by the regenerative braking system would cause the sensed parameter to approximate but not exceed the parameter threshold of the battery;
• and
• f. if the change in the parameter would cause the sensed parameter to remain within the parameter threshold, increasing the groundspeed of the vehicle to one at which the change in the parameter caused by the regenerative braking system would cause the sensed parameter to approximate but not exceed the parameter threshold of the battery and which does not exceed the maximum operating groundspeed.